"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:8931565a-5afc-4be0-9071-6dd184875758","http://resolver.tudelft.nl/uuid:8931565a-5afc-4be0-9071-6dd184875758","Development of a High-Temperature Industrial Heat Pump Model with a Novel Compressor Technology","Bashandy, Vincent (TU Delft Mechanical, Maritime and Materials Engineering)","Peeters, J.W.R. (mentor); Zhao, A. (graduation committee); Hooman, K. (graduation committee); Goosen, J.F.L. (graduation committee); Delft University of Technology (degree granting institution)","2024","The current global environmental crisis has resulted in increased efforts towards more efficient and sustainable industrial processes. High-temperature heat between 150 ◦C & 400 ◦C accounts for a major part of the energy demand in industrial processes. At the same time, large quantities of waste heat are unutilised at temperatures up to 200 ◦C. A heat pump could upgrade this waste heat to cover a part of the demand, resulting in considerable savings both for the planet and the operator. Nevertheless, heat pumps have seen little development in heat delivery temperatures above about 150 ◦C. This research aims to assess the current technological potential and limitations of high-temperature heat pumps. Subsequently, solutions and recommendations are developed.
Focussing on mechanical vapour compression heat pumps, a thorough understanding of such cycles is gained first. The performance of a heat pump is highly dependent on the choice of cycle setup and working fluid, with the compressor posing the largest limitations for higher temperatures. To assess these, this project develops a heat pump model which simulates many different working fluids for different component configurations. The model was subjected to two temperature domains, covering waste heats of 100 ◦C & 200 ◦C and process heat temperatures in the range of 150 ◦C to 400 ◦C.
Results were obtained for all fluids incorporated in RefProp 9.0 and showed that multistage compression with intercooling and superheating considerably improved the performance of nearly all fluids. By comparing fluids based on efficiencies, capacities, temperatures and pressures, benzene and propylcyclohexane showed the best performance for the lower and higher part of process heat temperatures, respectively. The results however also showed the potential superiority of water as it has the best efficiencies and the largest applicability range, which combines with the hazard-free & environmentally friendly nature, low cost and wide availability. The main downside of water appeared to be the persistent, unacceptably high compression temperatures, combined with large pressures and pressure ratios. It was subsequently investigated how the disadvantages of water could be handled. A solution was found in the usage of Liquid Piston Gas Compression (LPGC), in which a rising liquid column, supplied by a pump, acts as a reciprocating piston in a compression chamber. This setup conveniently allows for liquid spray injection to cool the steam upon compression and alleviates limitations on the pressure ratio. By using the same water as the liquid in the LPGC, any temperature rise is compensated by the evaporation of liquid, resulting in more steam with a lower temperature. A numerical model of this type of compressor was made in which dynamics were modelled down to individual droplets. This simplified approach provided insight into the compression path with such liquid injection and allowed the approximate determination of the required amount of spray. Results showed that the injection could cool the vapour adequately even for high temperature lifts. The LPGC was subsequently incorporated into a single-stage heat pump cycle and compared the results for other fluids using ordinary compressors. These results showed large CoP improvements of 15-25 % CoP and low discharge temperature. With that, it was shown that an environmentally friendly fluid could be used in a simple single-stage configuration and still provide the best performance compared to any other fluid.","High-temperature heat pumps; liquid piston gas compression; Vapor compression heat pump; water; Intercooling; Superheating","en","master thesis","","","","","","","","","","","","Mechanical Engineering | Energy, Flow and Process Technology","",""
"uuid:22a483ae-2aec-4cfc-93c3-8b6833e2fd8f","http://resolver.tudelft.nl/uuid:22a483ae-2aec-4cfc-93c3-8b6833e2fd8f","Optimization of The Energy Systems of Residential Buildings Using PV, Heat Pump and Battery Technology: Designing and optimizing the energy systems of residential buildings in various cities with PV, heat pump and battery storage technologies by adding new features to the PVMD Toolbox","Kodzhabash, Tekin (TU Delft Electrical Engineering, Mathematics and Computer Science)","Santbergen, R. (mentor); Blom, Y. (graduation committee); Delft University of Technology (degree granting institution)","2024","This thesis addresses the imperative need for sustainable energy solutions in the residential sector which is a significant contributor to global energy consumption and greenhouse gas emissions. Focusing on modeling and optimizing residential energy systems, the study explores the integration of photovoltaic (PV) panels, heat pumps, and batteries. The purpose is extending the applications of the Photovoltaic Material and Devices (PVMD) toolbox, offering a framework for future research and advancements. The objective is to enhance energy efficiency, reduce carbon footprints, and contribute to energy security by diversifying energy sources.
The research encompasses a comprehensive analysis of heat pump models, emphasizing their role in space heating, space cooling, and domestic hot water functions. Two specific models are chosen for Coefficient of Performance (COP) and Energy Efficiency Ratio (EER) calculations. These models, along with the utilization of the nPro tool, lay the foundation for integrating heat pump systems with PV production and battery storage in residential buildings.
The study successfully integrates the model of the battery’s performance and the overall grid-connected energy system. Employing a mathematical modeling approach, each component is systematically incorporated into the system, including the previously developed heat pump model. This integration, coupled with the Alternating Current (AC) output of the PVMD toolbox and the battery, establishes the groundwork for subsequent economic and performance analyses of the system.
The study systematically selects various locations with different environmental conditions such as Equivalent Sun Hours (ESH) and average ambient temperature to analyze the economic aspect by checking the Net Present Cost (NPC) and performance aspects by checking Self Consumption Ratio (SCR) and Self Sufficiency Ratio (SSR) of the integration model. The findings emphasize the economic viability of heat pump investments in cities with distinct heating and cooling demands. It has been demonstrated that in colder cities where heating demand is predominant, heat pumps are economically attractive, resulting having heat pumps in optimal scenarios that give the minimum NPC in Amsterdam and Lisbon. Additionally, although the individual components of the system may seem cost-ineffective, their value is derived more from integration in milder cities where heating demand is dominant, resulting having heat pump and PV integrated for the optimal scenario for Lisbon. However, cities dominated by cooling demand face challenges in achieving financially optimal designs because the operational savings for cooling cannot be accurately included such as Cairo and Dakar. The research underscores the importance of considering various system factors, including initial investment costs and electricity tariffs, to achieve financially optimal sizing. As the initial cost of the battery decreases, battery technology becomes economically appealing for Lisbon and Dakar. Moreover, changes in the tariff prove economically favorable for integrating the battery system in Lisbon, Cairo, and Dakar.
This work contributes valuable insights to the field of renewable energy, providing practical solutions for the transition towards cleaner and more efficient residential energy systems.","Residential building; PV panels; Heat pump; Battery Energy Storage System (BESS); NPC","en","master thesis","","","","","","","","","","","","Electrical Engineering | Sustainable Energy Technology","",""
"uuid:6afd744c-906a-430d-a573-4382492596b3","http://resolver.tudelft.nl/uuid:6afd744c-906a-430d-a573-4382492596b3","Model Predictive Control for a Heat Pump System with Thermal Storage Tanks: Economical Operation and Demand-Side Management","Tang, Weihong (TU Delft Mechanical, Maritime and Materials Engineering)","Keviczky, T. (mentor); Li, Y. (mentor); Walker, S. (graduation committee); Khosravi, M. (graduation committee); Delft University of Technology (degree granting institution)","2024","In light of the pressing challenges posed by global climate change and the imperative to reduce CO2 emissions, innovative approaches in energy management are critically important. This thesis presents an exploration of heat pumps integrated with Thermal Storage System (TES) systems, an area of research and application pivotal for enhancing energy efficiency and environmental sustainability. The combination of heat pumps and TES systems emerges as a key factor in reducing greenhouse gas emissions and optimizing the utilization of renewable energy. Such integration plays a crucial role in minimizing operational costs, reducing environmental negative impact, and augmenting system efficiency by enabling the storage and later use of energy from renewable sources. Moreover, this integration facilitates the effective management of demand-side energy, bolstering the capacity to incorporate fluctuating renewable generation into the energy grid. This is achieved by dynamically load shifting to balance energy supply and demand.
A central aspect of this thesis is the utilization of Model Predictive Control (MPC) for advanced energy management. The research delves into the use of MPC to optimize the operational economy of the system, aiming to maximize cost-efficiency. Additionally, an innovative MPC-based Demand-Side Management (DSM) strategy is introduced. This strategy involves two key steps: initially establishing a model to assess the system's energy flexibility, followed by harnessing this flexibility to respond to demand fluctuations. Such an approach facilitates dynamic adaptation to varying energy demands, ensuring optimal resource utilization. The predictive capability of MPC, which accounts for future disturbances including demand forecasts, electricity pricing, and weather conditions, is exploited to improve the system’s responsiveness and operational efficiency.
Experimentation was conducted both in simulations and through the implementation in real systems. These practical applications demonstrated significant savings in energy costs and energy consumption, achieving economical operation. Furthermore, the execution of the proposed two-step demand-side management strategy successfully managed energy demands. This not only underscores the practical effectiveness of the proposed system but also highlights its potential in real-world scenarios.
In summary, this research underscores how the integration of heat pumps, TES systems, and advanced control strategies like MPC can significantly improve energy efficiency, reduce operational costs, and enhance energy flexibility. It highlights the vital role of incorporating sophisticated control mechanisms into sustainable energy systems, aligning with the strategic goals of modern energy policies and advancing the field of sustainable energy management.","MPC; Heat pump; Demand Side Management; Model Predictive Control","en","master thesis","","","","","","","","2026-01-25","","","","Mechanical Engineering | Systems and Control","",""
"uuid:b4f6a4a4-2e48-4bbe-9093-3f1368282f63","http://resolver.tudelft.nl/uuid:b4f6a4a4-2e48-4bbe-9093-3f1368282f63","Integrated Design Optimization of Electrically-Driven Vapor Compression Cycle Systems for Aircraft: Powered by High-Speed Centrifugal Compressors","Giuffré, A. (TU Delft Flight Performance and Propulsion)","Colonna, P. (promotor); Pini, M. (copromotor); Delft University of Technology (degree granting institution)","2024","In 2022 the aviation sector accounted for 1.9%of global greenhouse gas emissions, 2.5% of global CO2 emissions, and 3.5% of effective radiative forcing. To reach the long-term target of net zero emissions, revolutionary aircraft designs, featuring electrified or hydrogen powered propulsion systems, are needed. At the same time, the electrification of the non propulsive aircraft subsystems is necessary to comply with the requirements of emissions abatement in the short and medium time horizon.
Among the auxiliary subsystems, the Environmental Control System (ECS) is the largest consumer of non-propulsive power, accounting for up to 3-5% of the total fuel burn. The replacement of the conventional Air Cycle Machine (ACM) with an electrically-powered ECS based on the Vapor Compression Cycle (VCC) system could enable: i) a substantial decrease in fuel consumption; ii) a finer regulation of the relative humidity in the air distribution system, leading to improved air quality in the cabin and flight deck; iii) a reduction in maintenance costs and an increase in system reliability, due to the removal of the maintenance-intensive bleed system. However, the adoption of VCC systems in the aerospace sector has been historically very limited, due to safety concerns regarding the ozone depleting potential, toxicity and flammability of the working fluids used as refrigerants, as well as because of a lack of research specifically targeting airborne applications.
This dissertation documents research work performed as part of the NEDEFA project, which entails the investigation of VCC-based ECS architectures powered by oil-free highspeed centrifugal compressors. The first objective is to advance of the state-of-the-art regarding high-speed compressors operating with gas bearings, i.e., the key technological enablers of airborne VCC systems. The second target is to develop of a methodology for the integrated design of aircraft ECS, namely, a design philosophy in which the system and the main components are optimized simultaneously.
The main outcomes of this work are the development of a preliminary design model for high-speed compressors, extensively validated with experimental data and computational fluid dynamics simulations, and the implementation of an integrated design framework for aircraft ECS, embedding a multi-point and multi-objective optimization strategy. The compressor model has been applied to derive design guidelines for single-stage and twin-stage machines operating with arbitrary working fluids, as well as to perform the fluid dynamic design optimization of the compressor that will be installed in the IRIS (Inverse organic Rankine Integrated System) test rig of the Propulsion and Power Laboratory. Furthermore, the integrated design method has been used to size and compare the performance of two alternative ECS configurations for a single-aisle, short-haul aircraft resembling the configuration of an Airbus A320, i.e., a bleedless ACM and an electrically driven VCC. The results reveal that the optimal VCC system could be both more efficient and lighter than the corresponding ACM architecture, leading to potential fuel savings in the order of 20% for the prescribed application.
IBE) and energy-efficient way (0.673 kWeh/kgIBE) while allowing full recycle of biomass and most of the separated water. Besides improving yield by continuously recovering the inhibitory products, fermentation can be further enhanced by avoiding biomass loss and reducing water requirements. Lastly, the implemented energy-saving techniques ensure complete electrification of the proposed IBE recovery process. Therefore, the original results of this research study significantly contribute to the development of sustainable biofuel production processes.","Azeotropic dividing-wall column; Downstream processing; Heat pumps; Process electrification; Process intensification","en","journal article","","","","","","Funding Information: All persons who have made substantial contributions to the work reported in the manuscript (e.g. technical help, writing and editing assistance, general support), but who do not meet the criteria for authorship, are named in the Acknowledgements and have given us their written permission to be named. If we have not included an Acknowledgements, then that indicates that we have not received substantial contributions from non-authors. Publisher Copyright: © 2024 The Author(s)","","","","","BT/Bioprocess Engineering","","",""
"uuid:e6472160-3d10-4a1c-8241-759fe215e85e","http://resolver.tudelft.nl/uuid:e6472160-3d10-4a1c-8241-759fe215e85e","Improving plant-level heat pump performance through process modifications","de Raad, B.W. (TU Delft Energie and Industrie); van Lieshout, Marit (Rotterdam University of Applied Sciences); Stougie, L. (TU Delft Energie and Industrie); Ramirez, Andrea (TU Delft ChemE/Chemical Engineering)","","2024","Heat pumps are a promising option to decarbonize the industrial sector. However, their performance at a plant-level can be affected by other process changes. In this work, process changes that improve the heat pump's performance have been identified using Process Change Analysis (PCA), where the background pinch point is used as a reference point for appropriate placement. The effects of the process changes on the heat pump's work requirements are studies by introducing exergy to PCA to form the split exergy grand composite curve. This graph shows the work potential of the streams connected to the heat pump and therefore its work targets. The framework is demonstrated in two case studies. In a biodiesel production plant, it allowed to identify technologies that enhance heat pump performance while reducing overall heating requirements. Here, a heat pump transfers 1.9 MW with a COP of 4.2 but incurs a 40 kW penalty for transferring heat above the background process's pinch temperature. Replacing the wet water washer with a membrane separation unit avoided this penalty, while drastically reducing energy requirements from 0.9 MW to 0.3 MW. in a vinyl chloride monomer-purification process, PCA showed how the extraction of heat by the heat pump impacted the formation of the background pinch, from which an implementation strategy was derived that increased the heat pump's plant-level performance by 6.5% with respect to standard implementation.","Exergy grand composite curve; Heat pumps; Pinch analysis; Process change analysis","en","journal article","","","","","","","","","","ChemE/Chemical Engineering","Energie and Industrie","","",""
"uuid:f7d604b6-cb03-43be-8091-743dd2ccbe3f","http://resolver.tudelft.nl/uuid:f7d604b6-cb03-43be-8091-743dd2ccbe3f","Thermodynamic analysis and heat exchanger calculations of transcritical high-temperature heat pumps","Zhao, A. (TU Delft Energy Technology); Pecnik, Rene (TU Delft Energy Technology); Peeters, J.W.R. (TU Delft Energy Technology)","","2024","Heating in industrial processes is responsible for approximately 13% of greenhouse gas emissions in Europe. Switching from fossil-fuel based boilers to heat pumps can help mitigate the effect of global warming. The present work proposes novel high-temperature transcritical heat pump cycles targeted at heating air with a mass flow rate of 10 kg/s up to 200 °C for spray drying processes. Four low-GWP refrigerants, R1233zd(E), R1336mzz(Z), n-Butane, and Ammonia are considered as the candidate working fluids. The pressure ratio of the compressor is optimized to achieve a maximum coefficient of performance (COP) for the four working fluids. A shell & tube heat exchanger is considered as the gas cooler. Using a generalized version of the ϵ-NTU method, the gas cooler is sized and a second law analysis is conducted. Striking a balance between the first- and second-law performance and size of the gas cooler, the R1233zd(E) transcritical heat pump cycle with a COP of 3.6 is judged to be the most promising option.","Heat pump; Low-GWP refrigerants; Second law analysis; Transcritical","en","journal article","","","","","","","","","","","Energy Technology","","",""
"uuid:7c261e38-6309-487c-9df7-145c291f430b","http://resolver.tudelft.nl/uuid:7c261e38-6309-487c-9df7-145c291f430b","The electrification of industrial process heat: Implementation of thermal energy storage and the potential of novel high-temperature heat pump technologies","Verloop, Koen (TU Delft Mechanical, Maritime and Materials Engineering)","Hooman, K. (mentor); Zanetti, E. (graduation committee); Klein, S.A. (graduation committee); Delft University of Technology (degree granting institution)","2023","Electrification and decarbonization of industrial process heat is an important next step in the energy transition to reduce greenhouse gas (GHG) emissions. This study provides an in-depth analysis of how in the current industrial landscape the combination of commercially available electric heating technologies with the implementation of thermal energy storage (TES) can realize the electrification of
medium-temperature industrial process heat on the short-term. Moreover, it explores what potential novel high-temperature heat pump (HTHP) technologies, specifically the supercritical CO2 (sCO2) reversed Brayton HTHP, have to realize this electrification even more efficient in terms of electricity demand in the future. Thereby, it also briefly highlights the opportunities and challenges to combine HTHP technology and TES in the future to realize an optimal electrification.","Thermal energy storage; High-temperature heat pumps; Electric (E-)heating","en","master thesis","","","","","","","","","","","","Mechanical Engineering | Energy, Flow and Process Technology","",""
"uuid:ef26f5de-461b-4477-b4a4-47f32d8a33ba","http://resolver.tudelft.nl/uuid:ef26f5de-461b-4477-b4a4-47f32d8a33ba","Modelling of wet compression in compression-resorption heat pumps","Brancaccio, Marina (TU Delft Mechanical, Maritime and Materials Engineering)","Hooman, K. (mentor); Delft University of Technology (degree granting institution)","2023","The ever-increasing power demand, the high scarcity of fossil fuel resources and the growing environmental pollution have pushed the development on technologies related to sustainable energy systems. Maximizing the energetic performance of industrial processes is a key aspect in this quest for sustainable
energy management. A large share of waste heat below 100°C is rejected into the environment during industrial processes. This low temperature industrial waste heat can be a relevant heat source, reducing the consumption of fossil fuel and the emission of CO2 into the atmosphere. While these lower temperatures may not be suitable for direct industrial use and their capture may not be economically justified, the implementation of a heat pump allows for the elevation of these stream temperatures to levels that can support a wide range of industrial processes.
Heat pumps can be utilized to upgrade waste heat streams from low to higher temperature levels
which can then be used as energy supply for other industrial processes. State-of-the-art heat pumps are still restricted to temperature levels below 120°C due to long payback periods and technical limitations regarding the compressor. The application of heat pumps in industry could become more widespread if the technology would allow for a higher temperature output. Compression-resorption heat pumps (CRHPs) are a promising option to upgrade waste heat streams since they combine the advantages of absorption heat pumps (working with a mixture having non-isothermal phase transitions and low environmental impact) and vapor-compression heat pumps. CRHPs can operate both under dry and wet compression conditions. One of the main issues in reaching high temperatures with dry compression is the degradation of the oil, which leads to a reduction of the performance. Employing wet compression, the liquid can function as a lubricant avoiding both oil contamination and irreversibility caused by the superheating of the vapor. As pointed out by several researchers, a crucial point for the feasibility of high temperature CRHPs is a good value of isentropic efficiency for the compressor. As such, since a technological solution is currently not commercially available, the diffusion of CRHPs in the industrial processes is inhibited.
This research thesis develops a numerical model of the compressor in which the liquid phase and
the vapor phase are at non-equilibrium conditions. The model incorporates heat transfer between
the phases, yielding new insights and results. The validated model serves as a tool for analyzing
optimal operating conditions to maximize compressor efficiency. A case study within the dairy industry was considered. The results indicate a 60% reduction in operating costs and a saving of 104 tonnes of emissions if a single heat pump substitutes a traditional boiler. The substitution of fossil fuel fired boilers with heat pumps becomes increasingly necessary in light of the EU Renewable Energy Directive, ratified in 2023, which targets a 45% renewable energy share by 2030. The development of such next generation heat pumps could be a major breakthrough for optimizing energy management in industrial processes.","Heat pumps; Wet compression; oil-free compressor; twin screw compressor; ammonia-water; heterogeneous; modelling; double-phase flow; High temperature Heat Pumps; waste heat; Waste heat recovery; renewable energy","en","master thesis","","","","","","","","","","","","Mechanical Engineering | Energy, Flow and Process Technology","",""
"uuid:f4fc5dfa-fed2-4697-a2a1-5e1f43fa607c","http://resolver.tudelft.nl/uuid:f4fc5dfa-fed2-4697-a2a1-5e1f43fa607c","Developing a Sound Reducing Heat Pump Cover","Swen, Micha (TU Delft Industrial Design Engineering)","Tempelman, E. (mentor); Haans, M.C. (graduation committee); Hoogendoorn, Tim (graduation committee); Delft University of Technology (degree granting institution)","2023","The heat pump market is growing rapidly and new noise legislation creates issues for many people living in terraced housing and apartments. The assignment was to develop a sound reducing heat pump cover for Qventi. It should reduce the sound sufficiently, while being aesthetically pleasing and easy to assemble. It should also be smaller, lighter and sold for a lower price than the main competitors.
Through market analysis, it was found that 10-15dB reduction was needed to stay within legal limits and data was gathered about the types of heat pumps and sound reducing covers. Through interviews, installers were found to value ease of delivery, ease of installation and ease of quoting. There are researching users, who research and install by themselves, and there are outsourcing users, who leave everything to the installer.
An anechoic chamber was used to test an aesthetic cover of Qventi with varying configurations of foam. This had no noticeable effect on the sound level of the heat pump. However, the key heat pump frequencies were found, which led to the optimal foam thickness and sheet metal thickness for the final design.
Through nine iterations, the final design was reached. It consists of five sheet metal panels, with clamped-in foam. A recirculation plate splits the inner area into two compartments, preventing the recirculation of air. Anti-vibration foam is placed underneath the heat pump to prevent contact sound.
The model was optimised for assembly by reducing the part count and pre-assembling the panels. Two doors were created on the side panels for easy maintenance access. The roof panel slots into place using a hidden locking mechanism.
Magnelis was chosen as a metal for its high corrosion resistance, long lifespan, recyclability and low CO2 footprint. For the foam, stratocell whisper was chosen for its sound reduction capabilities, low weight, moisture resistance and long lifespan.
Qventi will sell a range of sizes, with the option of custom sizing using a configure to order workflow, where models, technical drawings and quotes are automatically generated based on the specific case of the user. The first model Qventi will bring to the market will be priced at €2065,- for consumers. It is lighter, lower cost, more compact and easier to install than its competitors.
Through an evaluation with users and installers, the hush was found to be more aesthetically pleasing than the rest of the market. Mainly because of the hidden screw holes and the sleek, clean and robust design.","Design for Manufacturing; Heat pumps; Acoustic absorption; Sheet metal; Foam","en","master thesis","","","","","","","","","","","","Integrated Product Design","",""
"uuid:9760c151-9bd8-4526-adeb-e0530d4aab8f","http://resolver.tudelft.nl/uuid:9760c151-9bd8-4526-adeb-e0530d4aab8f","Analyses of the Oil Management in High-Temperature Heat Pumps and Modelling of the Oil-Refrigerant Separation","Dekker, Victor (TU Delft Mechanical, Maritime and Materials Engineering)","Ramdin, M. (mentor); de Vries, Wouter (mentor); Delft University of Technology (degree granting institution)","2023","Due to financial and environmental benefits, the interest in high-temperature heat pumps, producing heat sinks above 100 °C, is rising. Research is intensifying, and technology is developing fast. However, of all the components of the heat pump cycle, the oil management system seems to be the least investigated, even though 12% of the faults in large-scale heat pumps are related to oil management. This study aims to develop a method that predicts the oil-refrigerant separation performance in high-temperature heat pumps.
Oil injection is necessary for high-temperature heat pumps to run without failures. The oil lubricates, seals and cools the compressor, increasing its performance and lifetime. However, if the oil is not separated correctly, it causes problems in the other components; The oil increases the pressure drop and decreases the heat transfer of the heat exchanger. Additionally, the refrigerant
partially dissolves in the oil, altering its thermophysical properties and increasing the risk of improper lubrication. Finally, the transport of the refrigerant deteriorates.
The oil management of a heat pump includes several components; an oil injector, oil separator, oil pump, oil sump/reservoir, oil temperature regulator and an oil filter. The core of oil management is the oil separator; three types of separation mechanisms are distinguished: impingement, centrifugal and coalescence. A centrifugal-type separator is most applied for industrial applications since it provides a wide operating range, allows high flow rates, and is simple and, thus, cheap to manufacture.
A data set containing the flow conditions and thermophysical properties is developed to use as input for the oil-refrigerant separation process modelling. A Daniel plot and developed correlations determine the properties of the oil-refrigerant mixture. The Tatterson equation is used to predict droplet size, and
the droplet distribution is described using the Rosin-Rammler distribution. A test case is designed to validate the developed method.
Finally, the oil separation due to a cyclone oil separator is modelled in Ansys fluent. A transient simulation based on the Reynolds stress modelling approach is conducted for the continuous phase. The discrete phase method simulates the oil-refrigerant droplets. The developed method serves as a strong foundation for future research. For the future, including models for droplet behaviour and wall-film models is strongly recommended to provide scientifically relevant outcomes.","lubricating oil; heat pump","en","master thesis","","","","","","","","2025-01-16","","","","Mechanical Engineering | Energy, Flow and Process Technology","",""
"uuid:ab3dbb90-f436-4ca1-9fdf-e99cff86e333","http://resolver.tudelft.nl/uuid:ab3dbb90-f436-4ca1-9fdf-e99cff86e333","Advanced downstream processing of bioethanol from syngas fermentation","Jankovic, T.J. (TU Delft BT/Bioprocess Engineering); Straathof, Adrie J.J. (TU Delft BT/Bioprocess Engineering); Kiss, A.A. (TU Delft ChemE/Product and Process Engineering)","","2023","Syngas fermentation is used industrially to produce diluted bioethanol (about 1–6 wt%). This research study proposes a novel downstream process that recovers bioethanol in an energy-efficient and cost-effective manner, improves fermentation yield by recycling all fermentation broth components (microbes, acetate and water), and is designed for full-scale industrial-level application. Therefore, vacuum distillation at fermentation temperature was conceptually studied as an initial ethanol recovery step, leading to a bottom stream that may be recycled. Advanced separation and purification techniques were designed to recover 99.5% of initially present ethanol as high-purity product (99.8 wt%). Mechanical vapor recompression and heat integration methods were used to maximize sustainability and eco-efficiency of the proposed recovery process. Implementation of these techniques on a process using 6 wt% ethanol feed stream decreased the total annual costs by 54.2% (from 0.175 to 0.080 $/kgEtOH), reduced the primary energy requirement by 66.1% (from 2.82 to 0.96 kWthh/kgEtOH), lowered the CO2 emission by up to 82.6% (from 0.414 to 0.072 kgCO2/kgEtOH), and reduced the fresh water usage by 62.6% (from 0.242 to 0.091 m3W/kgEtOH). Sensitivity analysis for ethanol concentrations ranging from 6 to 1 wt% showed that the recovery costs and energy use increased to 0.336 $/kgEtOH and 1.78 kWthh/kgEtOH respectively. Since ethanol recovery performs better but fermentation will perform worse at higher ethanol concentration in fermentation broth, there is a trade-off concentration for the overall process. The current analysis is an important step toward determining this trade-off.","Bioethanol; Downstream processing; Fluid separation; Heat pumps; Syngas fermentation","en","journal article","","","","","","","","","","","BT/Bioprocess Engineering","","",""
"uuid:af452225-2403-4183-ad73-3b9727641685","http://resolver.tudelft.nl/uuid:af452225-2403-4183-ad73-3b9727641685","Process systems engineering perspectives on eco-efficient downstream processing of volatile biochemicals from fermentation","Jankovic, T.J. (TU Delft BT/Bioprocess Engineering); Straathof, Adrie J.J. (TU Delft BT/Bioprocess Engineering); Kiss, A.A. (TU Delft ChemE/Product and Process Engineering)","","2023","Increasing concerns over environmental pollution, climate change and energy security are driving a necessary transition from fossil carbon sources to more sustainable alternatives. Due to lower environmental impact, biochemicals are rapidly gaining significance as a potential renewable solution, particularly of interest in Europe. In this context, process systems engineering (PSE) helps with the decision-making at multiple scales and levels, aiming for optimum use of (renewable) resources. Fermentation using waste biomass or industrial off-gases is a promising way for the production of these products. However, due to the inhibitory effects or low substrate concentrations, relatively low product concentrations can be obtained. Consequently, significant improvements in downstream processing are needed to increase the competitiveness of the overall bioprocesses. This paper supports sustainable development by providing new PSE perspectives on the purification of volatile bioproducts from dilute fermentation broths. Since purification significantly contributes to the total cost of biochemical production processes (20%–40% of the total cost), enhancing this part may substantially improve the competitiveness of the overall bioprocesses. The highly advanced downstream process offers the possibility of recovering high-purity products while enhancing the fermentation step by continuously removing inhibitory products, and recycling microorganisms with most of the present water. Besides higher productivity, the upstream process can be greatly improved by avoiding loss of biomass, enabling closed-loop operation and decreasing the need for fresh water. Applying heat pumping, heat integration and other methods of process intensification (PI) can drastically reduce energy requirements and CO2 emissions. Additionally, the opportunity to use renewable electricity instead of conventional fossil energy presents a significant step toward (green) electrification and decarbonization of the chemical industry.","biochemical production; downstream processing; distillation; heat pumps; heat integration; process intensification; electrification","en","journal article","","","","","","","","","","","BT/Bioprocess Engineering","","",""
"uuid:d3a38c97-88fb-4d64-bdc1-756bbe5d1c78","http://resolver.tudelft.nl/uuid:d3a38c97-88fb-4d64-bdc1-756bbe5d1c78","The techno-economic integrability of high-temperature heat pumps for decarbonizing process heat in the food and beverages industry","Dumont, Marina (Universiteit Leiden); Wang, Ranran (Universiteit Leiden); Wenzke, Diana (Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)); Blok, K. (TU Delft Energie and Industrie); Heijungs, Reinout (Universiteit Leiden; Vrije Universiteit Amsterdam)","","2023","High-temperature heat pumps (HTHPs) are an emerging technology to improve overall process efficiency and reduce energy demand while enabling a switch from fossil fuels to renewable electricity. New industrial HTHP technologies aim to achieve an output heat temperature of 250 °C, suitable for decarbonising the food and beverages industry considering its temperature requirements of <250 °C. Here, we employ a bottom-up approach to investigate the techno-economic feasibility of integrating new HTHP technologies into heat processes of the German food and beverages industry and estimate emissions reduction potentials under waste heat scenarios. Our results indicate that the new HTHP technologies could meet 12 TWh of process heat demand in the German food and beverages industry and cut emissions by 9% considering Germany's current electricity fuel mix. A modest carbon tax of 38 €/t CO2 eq. or higher makes the HTHPs cost-competitive with an optimised fossil fuel-based alternative.","GHG emissions abatement; High-temperature heat pumps; Industrial decarbonisation; Techno-economic assessment","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Energie and Industrie","","",""
"uuid:7a553909-664d-4536-b889-bf3f019a5535","http://resolver.tudelft.nl/uuid:7a553909-664d-4536-b889-bf3f019a5535","Life cycle cost analysis (LCCA) of Stirling-cycle-based heat pumps vs. conventional boilers","Khan, Umara (Åbo Akademi University); Zevenhoven, Ron (Åbo Akademi University); Stougie, L. (TU Delft Energie and Industrie); Tveit, Tor Martin (Olvondo Technology)","","2023","Heat pumps (HPs) which use low temperature (waste) heat and renewable energy sources to provide high temperature heat are widely regarded as a critical technology for reducing carbon dioxide emissions in the industrial sector. The HighLift technology considered here can provide high temperature output heat up to around 200 °C. This article focuses on the Life Cycle Cost Analysis (LCCA) method and its use for the economic evaluation of different industrial-scale heating methods i.e., a Stirling-cycle-based heat pump, a fossil fuel oil-fired boiler (OB), a bio oil-fired boiler (BOB), a natural gas-fired boiler (NGB) and a biogas-fired boiler (BGB). Many input parameters and boundary conditions apply to Sweden, where the considered heat pump is located. Findings from this study suggest that when comparing the life cycle costs of all these technologies Stirling-cycle-based heat pumps give more economic benefits than fossil fuel or biofuel-fired conventional boilers. For a typical 15-year lifespan, its total life cycle cost decreases in following order OB > BOB > NGB > BGB > SC-HP. The study indicates that replacing conventional boilers with a Stirling-cycle-based heat pump, despite an increased initial cost, would still be a cost-effective heating option due to lower operating and maintenance costs.","Levelized cost of energy (LCOE); Life cycle cost analysis (LCCA); Net present value (NPV); Stirling-cycle-based heat pump (SC-HP)","en","journal article","","","","","","","","","","","Energie and Industrie","","",""
"uuid:332c2f51-8859-4fc1-be1e-46977ac76626","http://resolver.tudelft.nl/uuid:332c2f51-8859-4fc1-be1e-46977ac76626","Identifying techno-economic improvements for a steam generating heat pump with exergy-based costs minimization","de Raad, B.W. (TU Delft Energie and Industrie; Rotterdam University of Applied Sciences); van Lieshout, Marit (Rotterdam University of Applied Sciences); Stougie, L. (TU Delft Energie and Industrie); Ramirez, Andrea (TU Delft ChemE/Chemical Engineering)","","2023","Steam generating heat pumps show great potential for reducing carbon emissions in the industrial sector. However, predicting their performance is challenging as the exergy destruction of e.g., compressors and expansion valves increases with the temperature lift and condenser temperature. With over seventy design improvements mentioned in the literature, selecting the most effective design improvements is crucial. In this study, energy and exergy-based methods were compared in their ability to identify design improvements for a single stage subcritical heat pump to produce steam from hot condensate. The energy-based method suggested the addition of a sequential compressor with an intermediate cooler; however, this design did not improve the heat pump's techno-economic performance. The suggestion of adding either an internal heat exchanger or a flash vessel by exergy-based methods did lead in both cases to improved techno-economic performance. The internal heat exchanger performed best and increased the coefficient of performance from 2.3 to 2.8 and reduced operational costs by 0.8 M€ after 5 years of operation. Additionally, the initial investment decreased by 135 k€, and the total costs of operation decreased from 10.3 M€ to 8.7 M€. These findings show that exergy-based methods are the way forward in identifying effective design improvements for steam generating heat pumps.","advanced heat pump configuration; Exergy-based costs minimization; High-temperature heat pump; Steam generation; Techno-economic analysis","en","conference paper","International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-06-21","","ChemE/Chemical Engineering","Energie and Industrie","","",""
"uuid:5d6106e8-e133-41f8-a26c-3d3ccec1e6f9","http://resolver.tudelft.nl/uuid:5d6106e8-e133-41f8-a26c-3d3ccec1e6f9","Layering strategies for active magnetocaloric regenerators using MnFePSi for heat pump applications","Pineda Quijano, D.F. (TU Delft RST/Fundamental Aspects of Materials and Energy); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics); Brück, E.H. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2023","The development of affordable magnetocaloric materials (MCM) with a giant magnetocaloric effect (MCE) has brought magnetocaloric heat pumps a step closer to commercialization. The narrow temperature range in which these materials exhibit a large MCE demands the use of several materials with Curie temperatures covering the temperature span of the heat pump in a so-called layered active magnetocaloric regenerator (AMR). How to place these materials in the AMR in terms of distribution of Curie temperatures and thickness of each layer is still a topic of study. In this research we used a one dimensional numerical model to unveil potential benefits of either using a distribution of Curie temperatures that follows a sigmoidal shape or using thicker layers at the cold and hot ends of the AMR along with a linear distribution of Curie temperatures. We found that these AMRs are less sensitive to changes in the hot and cold reservoir temperatures compared to an AMR that uses just a linear distribution of Curie temperatures with uniform layer length, but only the one with thicker ends produces similar heating capacities and second law efficiencies. The heating capacity of the simulated AMR with a sigmoidal distribution of Curie temperatures varies only 5.6 % in a high utilization scenario, flow rate 37.5 g/s and a frequency of 0.75 Hz, when the hot side temperature changes from 308 K to 312 K and the temperature span is 18 K while the corresponding change is 8.7 % for the AMR with thicker end layers, and 37.9 % for the one with a linear distribution of Curie temperatures. For the considered geometry and operating conditions, the maximum heating capacities with temperature span 27 K in the high utilization scenario are 28.6 W, 23.0 W, and 28.5 W, whereas the corresponding second law efficiencies are 33.2%, 27.3 %, and 32.7% for the AMRs with linear distribution of Curie temperatures, sigmoid distribution, and linear distribution with thicker ends respectively.","Layered AMR; Layering strategies; Magnetocaloric heat pump; MnFePSi; Numerical simulation; Packed bed","en","journal article","","","","","","","","","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:8d8df0b7-e0b7-4e0b-8e52-4a158257978c","http://resolver.tudelft.nl/uuid:8d8df0b7-e0b7-4e0b-8e52-4a158257978c","Assessing the grid impact of Electric Vehicles, Heat Pumps & PV generation in Dutch LV distribution grids","Damianakis, Nikolaos (TU Delft DC systems, Energy conversion & Storage); Chandra Mouli, G.R. (TU Delft DC systems, Energy conversion & Storage); Bauer, P. (TU Delft DC systems, Energy conversion & Storage); Yu, Y. (TU Delft DC systems, Energy conversion & Storage)","","2023","Low Carbon Technologies (LCTs), such as Photovoltaics (PVs), Electric Vehicles (EVs), and Heat Pumps (HPs), are expected to cause a huge electric load in future distribution grids. This paper investigates the grid impact in terms of over-loading and nodal voltage deviations in different distribution grids due to increasing LCT penetrations. The major objectives are the identification of the most severe LCT, grid impact issue, seasonal effect, and vulnerable distributional area, considering the physical models of the LCTs. It is concluded that Winter is the most hazardous for the future grid impact, characterized by nearly 3 times higher over-loading and 2.5 times higher voltage deviations during high HP penetrations, while suburban areas are the most vulnerable. Moreover, while HPs seem to have, in general, a greater impact compared to EVs, EVs cause more prolonged violations. While this work follows a bottom-up approach, using detailed physical models, aggregated national data has also been acquired, which is often used by top-down approaches. Different grid impact issues have been compared for the two approaches in terms of magnitude and duration. While bottom-up approaches generate more pessimistic results regarding the magnitude of the violations, results about the duration of the violations can be contradictory.","Distribution grids; EVs; Grid impact; Heat pumps; LCT; PVs","en","journal article","","","","","","","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:e5431373-7f01-4029-a467-d27e69ace94f","http://resolver.tudelft.nl/uuid:e5431373-7f01-4029-a467-d27e69ace94f","Risk-averse Estimation of Electric Heat Pump Power Consumption","Damianakis, Nikolaos (TU Delft DC systems, Energy conversion & Storage); Chandra Mouli, G.R. (TU Delft DC systems, Energy conversion & Storage); Bauer, P. (TU Delft DC systems, Energy conversion & Storage)","","2023","An important aspect of the energy transition is the expected grid impact due to the abrupt increase of distributed electric generation and electric load demand. A part of this impact is going to be inflicted by the electrification of heating with heat pumps (HPs). Therefore, it is essential that the future power consumption of electric heating is estimated. This work develops a power estimation model without the use of heating demand data, needing only weather data and building heat pump specifications. Moreover, it is characterized as a risk-averse estimation since it uses no optimal control and utilizes the heat pump output capacity curves giving simultaneous priority to the customers' thermal comfort. Finally, it also estimates the power savings of electric heating due to future buildings' new insulation and energy label norms, revealing their importance.","air-sourced heat pumps; COP; floor-heating; insulation; power consumption","en","conference paper","Institute of Electrical and Electronics Engineers (IEEE)","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-04","","","DC systems, Energy conversion & Storage","","",""
"uuid:be398b96-b0c2-40e1-9d04-d2a74c9fb5b6","http://resolver.tudelft.nl/uuid:be398b96-b0c2-40e1-9d04-d2a74c9fb5b6","A numerical study of a wastewater-air source hybrid heat pump for domestic use","Bunikyte, Ugne (TU Delft Mechanical, Maritime and Materials Engineering)","Pecnik, R. (mentor); Wapperom, S.H. (mentor); Delft University of Technology (degree granting institution)","2022","To face the ongoing climate crisis, the Dutch government adopted a number of policies and measures to limit its greenhouse gas emissions. It is estimated that 10% of Dutch annual emissions are caused by the built environment, a large portion of which come from two sources: space heating and domestic hot water.
The use of heat pumps is said to meaningfully contribute to the electrification of domestic heat supply. However, heat pumps face intermittency issues during unfavourable climate conditions when heating is most needed, thus limiting their potential of being standalone heating systems.
A hybrid heat pump - meaning a single heat pump operating with multiple renewable heat sources - could efficiently provide heat all year round with maximised performance. However, literature on the subject is sparse and non-systematic. Therefore, conclusions on the system performance and its variability cannot be drawn.
Thus, the aim of this project was to create a modular numerical model of a hybrid heat pump system to analyse its performance. This was achieved by individually modelling and experimentally validating each component.
The chosen heat sources were wastewater and air. The numerical model showed satisfactory correlation with experimental results for each component, particularly the condenser of the heat pump, air source and wastewater storage bag. Improvements could be made in the evaporator of the heat pump, boiler and spiral heater.
After analysis of its yearly performance, it may be concluded that the modelled hybrid heat pump is not currently a worthwhile investment for a typical Dutch home. However, with a higher capacity heat pump, alongside other component and control optimisations, the system can be an all-electric alternative to many gas-heated homes.","Renewable energy; Heat pump; Hybrid heat pump","en","master thesis","","","","","","","","2024-11-18","","","","","",""
"uuid:f6e99f5a-7eaa-49f8-9df4-68ac34e14dca","http://resolver.tudelft.nl/uuid:f6e99f5a-7eaa-49f8-9df4-68ac34e14dca","A heat pump decision tool for homeowners: An advise leading to the benefits of the homeowner and a contribution to the energy transition of the built environment","Kolman, Stephan (TU Delft Architecture and the Built Environment)","van den Ham, E.R. (mentor); Bergsma, A.C. (graduation committee); Heintz, John L. (graduation committee); Delft University of Technology (degree granting institution)","2022","The Netherlands is in de midst of an energy transition, 7 million households and 1 million buildings that are currently poorly insulated and heated by natural gas must be transformed into well-insulated buildings and heated with a sustainable heat source. The government encourages homeowners to make their home more sustainable by providing subsidies for insulation and sustainable heating technologies such as heat pumps. Heat pump manufacturers are seizing their opportunity by developing online heat pump decision-making tools that allow homeowners to check whether their home is already suitable for a sustainable heat pump system, said they do this mainly out of their own interest to sell more heat pumps. In addition, there are also independent organizations that develop online heat pump decision making tools, they do this more out of interest for the climate. But it’s not clear whether these tools provide all the information and advice a homeowner needs before engaging an installer to install a heat pump system. In addition, it is not clear whether existing tools provide right advice to support the energy transition. Therefore existing online tools are analysed and reflected on through literature and additional research in order to develop a better tool. Therefore the main research question in this thesis is:
How is a heat pump decision tool for homeowners with limited technological knowledge designed, which gives an advice that contributes to the energy transition of the built environment and which provides an advice on which heat pump system and additional measures a homeowner should consider before engaging an installer?
First a literature study is conducted into the energy problems related to space heating in the Dutch built environment. Possible sustainable sources and heat pump systems with a high contribution to the energy transition are defined. These sources and systems are then included in the newly designed heat pump decision making tool.
Existing online heat pump decision making tools are then analysed in order to function as a basis to define all aspects a homeowner should consider before purchasing a heat pump system. A review is made on the basis of the literature study carried out earlier in which areas the advice of the existing tools is lacking. These shortcomings are addressed in the new tool.
Thirdly based on an example home, it is investigated which measures during an energy renovation that a home ultimately uses less energy, emits less CO2, is heated sustainably and has an higher indoor comfort. These findings are included in the new tool.
The new heat pump decision making tool is then developed on the basis of flow diagrams. All decision moments are based on the findings from the various conducted studies. These flowcharts are eventually converted into a digital online heat pump decision making tool. With this new tool, the homeowner is provided with all the necessary research-based information before engaging an installer to purchase a heat pump system. This assures the homeowner of correct advice without the involvement of an installer, which leads to a major contribution to the energy transition, better indoor comfort and lower heating costs.
Overall it can be concluded that: insulating the home first as described in the tool (minimum label B according to the insulation standard) leads to the highest contribution to the energy transition and a higher indoor comfort. And that the choice of the heat pump systems depends on the home-specific aspects, and the wishes of the homeowner.","Heat pump; Energy transition; Decision Making Tool; Home owners","en","master thesis","","","","","","","","","","","","Architecture, Urbanism and Building Sciences | Building Technology","",""
"uuid:597fed16-98bd-4e14-b7da-33242fcc0824","http://resolver.tudelft.nl/uuid:597fed16-98bd-4e14-b7da-33242fcc0824","Thermodynamic Modeling of High Temperature Heat Pump Systems","Vermani, Sanjay (TU Delft Aerospace Engineering)","de Servi, C.M. (mentor); Delft University of Technology (degree granting institution)","2022","Industrial processes are estimated to be responsible for about 20 % of the total greenhouse gas emissions within the European Union (EU). The majority of the industrial energy demand is related to the thermal energy required for process heating. Thus, there is a need to make radical changes to the industrial heating supply to achieve net-zero CO2 emissions. In this regard, high-temperature heat pump systems are being studied as an alternative to conventional fossil fuel-based systems. This project focuses on the modeling and analysis of thermodynamic characteristics of the two heat pump concepts, namely, reverse Rankine cycle based and reverse Brayton cycle-based systems. Both heat pump concepts are compared for high-temperature applications in terms of performance, design feasibility of the key components, and ease of integration with industrial processes.","High temperature Heat Pumps; Heat pump; Waste heat recovery; centrifugal compressor","en","master thesis","","","","","","","","","","","","Aerospace Engineering","",""
"uuid:31ba7e70-7de5-4e1d-b41e-e4a6e8e5f435","http://resolver.tudelft.nl/uuid:31ba7e70-7de5-4e1d-b41e-e4a6e8e5f435","Development of a heat pump system for mobile applications","Bokil, Siddharth Rahul (TU Delft Mechanical, Maritime and Materials Engineering)","Vlugt, T.J.H. (mentor); Karremans, Erik (graduation committee); Delft University of Technology (degree granting institution)","2022","The heating and cooling sector is one of the biggest sectors at this moment due to drastic fluctuations in climate parameters. Even though this sector helps in making sure everyone gets comfortable temperatures at the home, office, etc., there are environmental consequences attached to them. These consequences are in terms of emissions of greenhouse gases. Almost around 80% of the current greenhouse gas emissions are due to the demand for energy, mostly in the form of electricity and heat. Having looked at these emissions, the demand for heating and cooling in residential and commercial spaces is increasing day by day. The systems which provide the desired effect of cooling and heating use different working mediums i.e. fossil fuels and renewable sources which correspond to 75% and 22% usage in the EU currently. So, to reduce the consumption of fossil fuels, heat pumps came into the picture.
A heat pump uses a refrigerant through which heat transfer is carried out to attain the desired temperature at a particular location. The properties of these refrigerants and other component-based parameters affect the COP (Coefficient of Performance) of the system. For a mobile system, i.e. a portable heating and cooling device used for military camps, agricultural purposes currently use fossil
fuels which lead to enormous emissions, thus, these systems have to be redesigned by using vapor compression technology. One of the constraints is being able to use a refrigerant with GWP (Global Warming Potential i.e. a measure of the amount of heat a greenhouse gas traps in the atmosphere
comparing it with the same amount of CO2) of less than 150. Aspen model was created to assess different refrigerant behavior under some constraints like a cooling capacity of 40 kW, a heating capacity of 60 kW, and an air-air system with an airflow rate of less than 10000 m3/h, these requirements are
obtained from fossil fuel-based mobile systems, as these systems are air-air systems and system is kept outside the desired place, hoses have to be used to provide the air into and out of the system, thus, the specific air flow rate has to be achieved to get the desired temperature inside the desired place, similarly, 40-60 kW is a need for these systems due to high capacity applications. Sensitivity analysis of the aspen model was carried out by changing ambient temperature from 21 to 40 °C for cooling and -5 to 15°C for heating respectively, to quantify the behavior of refrigerants R290, R1234yf, R1234ze, R454C, R455A, R1270, R600a, R717, R516A. Exergy analysis was carried out along with the COP
calculations to examine the second law efficiency for all the refrigerants to see the feasibility of these refrigerants being an alternative option for widely used R410A refrigerant. By varying a few parameters considered for the heat pump systems, optimization and sensitivity analysis resulted in finding the most
suitable refrigerant for this system. For ease of calculations, a few assumptions and constraints were considered while simulating the system.
The maximum COP value obtained for the refrigerants R290, R1270, R1234yf, R1234ze, R454C, R455A, and R516 for cooling effect are 1.75, 1.77, 2.09, 1.91, 2.18, 2.25 and 2.21 respectively and similarly for heating effect are 3.61, 3.26, 2.49, 2.72, 3.56, 3.67 and 3.68 respectively. These COP values are obtained when the pressure drop across the heat exchangers is zero, so, the values with a
pressure drop of 0.5 bar will fluctuate a bit from these values. If not COP, it will surely affect all other component parameters. Apart from COPs, second law efficiency is also a crucial parameter to analyze the system performance compared to a Carnot system i.e. an ideal system. Exergy analysis helped
in quantifying the second law efficiency of the system for each refrigerant, which is calculated by the ratio of the actual COP of the system and Carnot COP of the system (Calculated by taking the source and sink temperature values). The maximum second-law efficiency values obtained for the refrigerants
R290, R1270, R1234yf, R1234ze, R454C, R455A and R516 for cooling effect are 0.32, 0.27, 0.2, 0.16, 0.29, 0.31 and 0.21 respectively and similarly for heating effect are 0.4, 0.41, 0.37, 0.45, 0.405, 0.42 and 0.41 respectively. So, by considering all the COP and second law efficiency values it can be
concluded that a suitable refrigerant for this system with good performance as well as safe to use and handle is R455A, and other potential refrigerants being R454C almost similar performance with respect to R455A, and R290 and R1270 single component refrigerants with the concern of higher flammability
can be used with further optimizations in the model.","Heat pumps; Vapour compression cycle; Low GWP Refrigerants; Exergy Analysis; Aspen Plus Modelling","en","master thesis","","","","","","","","","","","","","",""
"uuid:e6a1b7ec-d7f9-4381-ba77-92803f758132","http://resolver.tudelft.nl/uuid:e6a1b7ec-d7f9-4381-ba77-92803f758132","""It is just too much hassle!"": A stated choice experiment regarding the perception of hassle factors on the decision-making of heat pump adoption by homeowners in the Netherlands","Scherer, Tormo (TU Delft Technology, Policy and Management)","de Vries, G. (mentor); Chorus, C.G. (graduation committee); de Haas, M.C. (graduation committee); Delft University of Technology (degree granting institution)","2022","European and Dutch environmental goals prescribe that national emitted CO2 levels need to be reduced. Therefore, the Dutch government chose to transition the whole Dutch residential sector to gas-free living by 2050, to decrease CO2 levels. Homeowners are responsible themselves for adopting a sustainable heating system, where specifically heat pumps are one of the main proposed solutions. However, renovation rates are not expected to meet their determined goals. Hassle factors are a psychological barrier in homeowners' decision-making process, leading to inaction and delays. Therefore, it is determined what is perceived as a hassle and to what extent it is a barrier in homeowners' decision-making process.
Five main hassles were determined which impact the decision-making: ‘length of disruption’, ‘information gathering’, ‘subsidy and loan applications’, ‘finding a contractor’ and ‘neighbour consultation’. Next, their influence as a barrier has been examined through discrete choice modelling with the help of a stated-preference choice experiment containing in total 155 complete responses. The results of this study, for the first time, empirically validated that all five mentioned hassles negatively influence homeowners' decision-making. However, these five individual influences are best modelled as one combined hassle factor, which is perceived as more important than the financial profit a homeowner receives over the lifetime of a heat pump. Additionally, a latent class analysis was performed, finding significantly different preferences between two homeowners groups within the sample. Looking more closely at what a homeowner perceives as a hassle, the additional factor of ‘profit’ is found to have a de-hassling effect on the overall amount of hassle, indicating that context is important for homeowners. Looking more closely at the perceptions of hassle, differences between conscious and unconscious perceptions can be found.
The findings of this research show that reducing the five main hassles can be used to speed up the adoption process of heat pumps and contribute to reducing the adversities of climate change. Policymakers and businesses can perform interventions to decrease hassle or provide even ‘hassle-free’ alternatives by taking over tasks. The appropriateness of these interventions can be based on the derived value of time indicators created for each individual hassle factor. The use of context differentiations can be used as an additional tool via nudging and sludging to decrease or increase the perceived amount of hassle of choices. This research's overall value provides a better understanding of the psychological barrier hassle, which is rarely considered in homeowners' decision-making.","Hassle; Decision-making; Homeowners; Heat pumps; Choice modelling","en","master thesis","","","","","","","","","","","","Complex Systems Engineering and Management (CoSEM)","",""
"uuid:facce8a7-d3ee-4d61-92df-fc5b5f21194d","http://resolver.tudelft.nl/uuid:facce8a7-d3ee-4d61-92df-fc5b5f21194d","Using Peltier elements in low temperature district heating networks","kleyn Winkel, Lars (TU Delft Mechanical, Maritime and Materials Engineering)","Peeters, J.W.R. (mentor); Lösch, Carsten (mentor); Delft University of Technology (degree granting institution)","2022","By placing multiple Peltier elements in a linear arrangement while two water flows run past the elements, a temperature increase can be realised in one flow while the other flow is cooled down. In this study the heating of domestic hot water with Peltier elements as solid state heat pumps, and a heating network was investigated. A numerical model that solves the thermal energy balance within the Peltier elements was derived to describe the internal temperature distribution of the Peltier element, and its interaction with the domestic hot water and the heating network. The model was used to simulate the performance of 40 Peltier elements in a custom designed Peltier Heat Exchanger. Experiments were run to validate the numerical model. The numerical simulation of the temperature distribution within a Peltier Heat Exchanger and the temperature distributions observed in the experiments were not in agreement. The model input parameters Seebeck coefficient, resistance, thermal conductivity and a relation for the Nusselt number were re-evaluated using the experimental results. After the adjustment of the model input parameters, the new simulation results were able to accurately describe the temperature distribution with the Peltier Heat Exchanger. The Peltier Heat Exchanger was able to deliver domestic hot water with a COP between 1.2 and 1.8 depending on the flow speed of the domestic hot water and the heating network. The COP can potentially be increased by using Peltier elements with a higher Seebeck coefficient.","Peltier elements; Heating network; Domestic hot water; Coefficient of performance; Heat transfer; heat pump","en","master thesis","","","","","","","","","","","","Mechanical Engineering | Energy, Flow and Process Technology","",""
"uuid:7eed9da0-86c3-4b7d-82ae-abcd202f90a6","http://resolver.tudelft.nl/uuid:7eed9da0-86c3-4b7d-82ae-abcd202f90a6","FEA analysis of the Tree Heat Pump","Remmerswaal, Joost (TU Delft Industrial Design Engineering)","van der Vegte, Wilhelm Frederik (mentor); Minnoye, A.L.M. (mentor); Delft University of Technology (degree granting institution)","2022","The amount of Heat pumps in the Netherlands is on the rise mainly because of the climate accords that hope to abolish the use of natural gas. This project aims to improve upon the current design of heat pumps to answer to this increased market. This is done in collaboration with ThuisBaas and more specifically Errico Garofalo who created the concept design The Tree. This concept design is expanded upon and simulated in this master thesis.","FEA; Heat pump; Simulation","en","master thesis","","","","","","","","","","","","Integrated Product Design","",""
"uuid:93fdc1a2-740b-4908-8006-be3f1ebbacc1","http://resolver.tudelft.nl/uuid:93fdc1a2-740b-4908-8006-be3f1ebbacc1","Robust Optimal Control for Demand Side Management of Multi-Carrier Microgrids","Carli, Raffaele (University of Bari); Cavone, Graziana (University of Bari); Pippia, T.M. (TU Delft Team Tamas Keviczky); De Schutter, B.H.K. (TU Delft Team Bart De Schutter); Dotoli, Mariagrazia (University of Bari)","","2022","This paper focuses on the control of microgrids where both gas and electricity are provided to the final customer, i.e., multi-carrier microgrids. Hence, these microgrids include thermal and electrical loads, renewable energy sources, energy storage systems, heat pumps, and combined heat and power units. The parameters characterizing the multi-carrier microgrid are subject to several disturbances, such as fluctuations in the provision of renewable energy, variability in the electrical and thermal demand, and uncertainties in the electricity and gas pricing. With the aim of accounting for the data uncertainties in the microgrid, we propose a Robust Model Predictive Control (RMPC) approach whose goal is to minimize the total economical cost, while satisfying comfort and energy requests of the final users. In the related literature various RMPC approaches have been proposed, focusing either on electrical or on thermal microgrids. Only a few contributions have addressed the robust control of multi-carrier microgrids. Consequently, we propose an innovative RMPC algorithm that employs on an uncertainty set-based method and that can provide better performance compared with deterministic model predictive controllers applied to multi-carrier microgrids. With the aim of mitigating the conservativeness of the approach, we define suitable robustness factors and we investigate the effects of such factors on the robustness of the solution against variations of the uncertain parameters. We show the effectiveness of the proposed RMPC approach by applying it to a realistic residential multi-carrier microgrid and comparing the obtained results with the ones of a baseline robust method.","demand side management (DSM); Energy and environment-aware automation; Heat pumps; Microgrids; multi-carrier microgrid; Renewable energy sources; Resistance heating; robust model predictive control.; robust optimization; Robustness; set-based uncertainty; Stochastic processes; Uncertainty","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Team Bart De Schutter","","",""
"uuid:cc63a126-b6d7-4635-bdff-d9da42b8c1da","http://resolver.tudelft.nl/uuid:cc63a126-b6d7-4635-bdff-d9da42b8c1da","Importance of Model Fidelity of Power to X Devices in Energy System Analysis","Gusain, D. (TU Delft Intelligent Electrical Power Grids); Cvetkovic, M. (TU Delft Intelligent Electrical Power Grids); Yağci, Bekir Caner (Student TU Delft); Palensky, P. (TU Delft Intelligent Electrical Power Grids)","","2022","Power-to-X (PtX) technologies are accelerating the energy transition. Increasingly, these technologies are also being leveraged as flexible energy resources to support the electrical grid. PtX models are often represented using a constant efficiency term as a linear relation between the power input and energy output. However, the operational performance of any PtX device such as an electrolyser or an electric heat pump can depend on factors such as operational temperature. In this paper, we have developed and analyzed two levels of model fidelity of the most widely assessed PtX technologies: electrolyser and heat pump systems. We assess the impact of detailed models on operation of PtX within simulation-based energy system analysis. Our results show that for electrolyser systems, the efficiency errors can be almost 0.6%. With heat pump systems, the difference in COP can be as high as 1.4.","electrolyser; heat pump; model fidelity; power to x; temperature dynamics","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-01-12","","","Intelligent Electrical Power Grids","","",""
"uuid:e6fc33cc-1086-4325-b6db-740e80591d74","http://resolver.tudelft.nl/uuid:e6fc33cc-1086-4325-b6db-740e80591d74","The energy performance of dwellings with heat pumps of Dutch non-profit housing associations","van der Bent, H.S. (TU Delft Design & Construction Management); van den Brom, P.I. (TU Delft Building Energy Epidemiology); Visscher, H.J. (TU Delft Design & Construction Management); Meijer, A. (TU Delft Building Energy Epidemiology); Mouter, N. (TU Delft Transport and Logistics)","","2022","Achieving energy efficiency in the built environment requires extensive efforts in the renovation and adaptation of housing stock. A promising design solution is the heat pump. While gas boiler systems are commonly used in Dutch non-profit housing stock, the share of dwellings with a heat pump grew from 1.6% in 2017 to 3.2% in 2021. However, building characteristics and the energy consumption of dwellings with a heat pump are unclear. Therefore, a dataset of 69,422 dwellings with different types of heat pumps has been examined and compared to dwellings with a traditional HR107 condensing gas boiler. This research reports average characteristics and the average actual energy consumption of dwellings with all-electric, hybrid and gas absorption heat pump systems. Dwellings with a heat pump system are on average of higher building quality, their gas consumption is lower and their electricity consumption is higher than dwellings with an HR107 condensing gas boiler. Detailed insight is provided for dwellings with different heat pump systems and for dwellings with different building characteristics. Further research to determine the energy performance of dwellings with specific heat pump configurations is recommended in light of the energy transition in the built environment.","energy consumption; Heat pump systems; housing stock; non-profit housing","en","journal article","","","","","","","","","","","Design & Construction Management","","",""
"uuid:3c5d4ac6-66b1-4a7b-8aab-5a782da5e209","http://resolver.tudelft.nl/uuid:3c5d4ac6-66b1-4a7b-8aab-5a782da5e209","Assessing the Demand Response Potential of Heat Pumps in All-Electric Buildings Equipped with PV, EV (V2G) and BES to Minimize Energy Costs","Gaona, David (Student TU Delft); Vermeer, W.W.M. (TU Delft DC systems, Energy conversion & Storage); Chandra Mouli, G.R. (TU Delft DC systems, Energy conversion & Storage); Bauer, P. (TU Delft DC systems, Energy conversion & Storage)","","2022","An integrated energy system consisted of PV panels, EV (electric vehicle), BES (battery energy storage), and a HP (heat pump) coupled with thermal storage tanks (TES) has been studied. The research aimed to minimize the total energy costs by scheduling the optimal power consumption of each device as response to two external signals as part of a demand response program. One of the signals corresponded to a selling electricity price tariff or feed-in tariff (FIT) to account for the ability of the system to sell energy towards the grid. On the other hand, the second signal corresponded to the buying electricity price tariff to account for the system's energy consumption from the grid. This control scheme allowed to determine the optimal energy consumption of the HP and its flexibility potential to shift its load towards times of low electricity prices. It was concluded that the proposed integrated system will produce a 50 % total energy cost reduction while the operation of the HP for one week in winter will reduce the gas consumption in 53 m3 in a traditional Dutch house.","Demand response program; heat pump (HP); thermal energy storage (TES); energy systems optimization; integrated energy systems","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-06-01","","","DC systems, Energy conversion & Storage","","",""
"uuid:8499fc01-5c9e-4ce2-b937-ac5641e0903f","http://resolver.tudelft.nl/uuid:8499fc01-5c9e-4ce2-b937-ac5641e0903f","L'effet de la taille et du fluide actif sur la conception multi-objectifs des compresseurs centrifuges à grande vitesse","Giuffré, A. (TU Delft Flight Performance and Propulsion); Colonna, Piero (TU Delft Flight Performance and Propulsion); Pini, M. (TU Delft Flight Performance and Propulsion)","","2022","The impact of size and working fluid on the efficiency, operating range, and axial thrust on bearings is examined for high-speed, oil-free centrifugal compressors. First, the development and validation of a reduced-order model based on scaling principles is documented. Then, the validated compressor model is used to generate design maps for stages operating with arbitrary fluid molecules, and characterized by different size. The results show that compressors operating with fluids made by heavy and complex molecules provide lower efficiency over the entire design space, if compared to their simple-molecule counterparts. However, compressors for complex-molecule fluids require lower rotational speed, and generate lower axial thrust on bearings, thus making them particularly suitable for small-scale applications. Furthermore, a decreasing value of the size parameter has a detrimental effect on the stage efficiency, as a result of manufacturing constraints. The results computed by the compressor model suggest that the efficiency penalty is more sensitive to variations of clearance gap than to surface finishing. Lastly, the reduced-order model has been used to perform a design exercise, i.e., the multi-objective optimization of the first compressor stage of the heat pump test rig being realized at Delft University of Technology. The key characteristics of the optimal compressor design has been compared to those derived from the design maps, to corroborate their validity. The optimal design has been extensively characterized by means of CFD, providing further evidence that efficient mini-compressors operating with organic fluids, and featuring pressure ratios up to five at off-design, are feasible.","Centrifugal compressors; Computational fluid dynamics (CFD); Environmental control system (ECS); Heat pumps; Multi-objective optimization; Working fluids","fr","journal article","","","","","","","","","","","Flight Performance and Propulsion","","",""
"uuid:40920e0d-ef7f-49f8-b979-73fed64baf68","http://resolver.tudelft.nl/uuid:40920e0d-ef7f-49f8-b979-73fed64baf68","The main utilization forms and current developmental status of geothermal energy for building cooling/heating in developing countries","Liu, Zhengxuan (TU Delft Design & Construction Management; Hunan University); Xing, Chaojie (Hunan University); Zeng, Chao (Southwest Jiaotong University); Zhou, Yuekuan (The Hong Kong University of Science and Technology)","","2022","Geothermal energy (GE), as an ideal renewable resource for building cooling/heating with stability and abundance in energy supply, has been widely exploited in developing countries. The common utilization forms of GE mainly include the ground source heat pump (GSHP), underground duct system (UDS), and abandoned wells energy (AWE) system. However, there is still a lack of comprehensive overview of the current developmental status of the GSHP, UDS, and AWE systems for building cooling/heating in developing countries. This chapter will be conducted from the following aspects: (1) The literature review and categories of GE utilization in the developing countries, mainly including the latest literature review on GE development and categories of utilization for building cooling/heating. (2) The common utilization of the GSHP system and its current application and development in the developing countries, mainly including the ground-coupled heat pump (GCHP) system and groundwater heat pump (GWHP) system. (3) The common utilization of the UDS system and its current application and development in the developing countries, mainly including the horizontal UDS system, vertical UDS system, and the corresponding coupled system with phase change energy storage and other advanced technologies. (4) The common utilization of the AWE system and its current application and development in the developing countries, mainly including the abandoned oil and gas wells. (5) The existing issues and in-depth analysis on the practical application of GE for building cooling/heating in the developing countries. This chapter can provide some effective guidelines on the various GE utilization forms for building cooling/heating in developing countries.","Abandoned wells energy; Building cooling/heating; Developing countries; Geothermal energy; Ground source heat pump; Underground duct system","en","book chapter","Elsevier","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Design & Construction Management","","",""
"uuid:299218d6-7f32-4ea1-a39e-cf3ab7cacb8e","http://resolver.tudelft.nl/uuid:299218d6-7f32-4ea1-a39e-cf3ab7cacb8e","Materializing the Demand Response Potential from Heat Pumps in the Netherlands in 2050: Investigating the Role of Consumer Behavior","Schumacher, Merel (TU Delft Technology, Policy and Management)","de Vries, G. (mentor); Chappin, E.J.L. (mentor); Delft University of Technology (degree granting institution)","2021","By the year 2050, the Dutch government aims to have transitioned away from natural gas and provide heating to all residential dwellings using more sustainable technologies. Heat pumps (both all-electric and hybrid models) are expected to play a large role in fulfilling this heating demand. However, because heat pumps require electricity in order to provide heating, a rise in the number of installed heat pumps is expected to have a significant effect on the residential electricity demand. This poses an issue during times of peak demand and low renewable power availability, leaving no choice but to increase reserves and ramping needs from fossil-fueled conventional power assets. Luckily, when provided with the right control strategy, heat pumps are able to flexibly draw electricity from the power grid, lowering the electricity required during peak hours. As a result, it is both possible that an increase of installed heat pumps in the Netherlands can either aggravate the flexibility problem or provide a key role in solving it.
The extent to which heat pumps could contribute to providing this demand response is not only dependent on the technical demand-response characteristics of the heat pumps. Rather, it is determined by both the willingness of households to adopt the heat pump and the way users react to the proposed control strategy. Using econometric techniques, the master thesis research project quantifies these behavioral dimensions into a model estimating the electrical flexibility heat pumps will be able to either require or provide in the Netherlands in 2050. In the research, several consumer typologies are defined distinguishing between consumer user groups and consumer adoption groups. The research finds that an additional 1.6 GW of flexibility can be provided by heat pumps in 2050 should policy be developed that targets consumer adoption behavior. Consumer user behavior has less of an influence on the average demand response potential of heat pumps, however could be an area of focus should a frequent demand response be desired.","Heat pump; Demand response; Adoption Behavior; User Behavior","en","master thesis","","","","","","","","","","","","Complex Systems Engineering and Management (CoSEM)","Energy Transition Lab",""
"uuid:71089afc-d43e-41f7-90fe-de66298d9713","http://resolver.tudelft.nl/uuid:71089afc-d43e-41f7-90fe-de66298d9713","The decarbonisation of process heat in the German food and beverages industry: A study quantifying the techno-economic potential of High-Temperature Heat Pumps in the German food and beverages industry, the GHG emission abatement potential, and evaluating the economic and political framework conditions for industrial decarbonisation","Dumont, Marina (TU Delft Technology, Policy and Management)","Blok, K. (mentor); Wang, Ranran (mentor); Delft University of Technology (degree granting institution); Universiteit Leiden (degree granting institution)","2021","Industrial decarbonisation has largely stagnated over the last years in Germany. A large share of Greenhouse Gas (GHG) emissions stem from the combustion of natural gas for producing higher temperature process heat. High-Temperature Heat Pumps (HTHPs) are an emerging technology that can upgrade waste heat with electrical input to high temperatures needed for the processes and thus can contribute to the electrification of industries. Hence, HTHP can significantly reduce GHG emissions stemming from the production of process heat. While residential heat pumps are widely commercially available due to lower temperature requirements, no HTHPs were installed in German industries in 2018 due to multiple technical, market, and knowledge barriers. HTHPs are expected to reach temperatures up to 250°C soon, making the food and beverages industry a suitable sector due to process temperature requirements at the lower industrial spectrum (<250°C). The International Energy Agency (IEA) outlines that HTHPs are a core emerging technology to replace fossil-fuel boilers in industry over the next decades. Thus, there is a large market ahead for manufacturers. This study evaluates the techno-economic potential of HTHPs in the Germany food and beverages industry. Further, it evaluates the GHG emissions abatement potential in relation to total GHG emissions of the industrial sector. This study has a generalized and systemic scope, thus does neither consider specific case studies, nor performs process optimization. It follows a bottom-up approach to include process- and technology-specific information and scales it up to national level. This study uses two waste heat scenarios, first considering an average 45°C industrial waste heat availability as worst-case, and second considering direct exhaust temperatures as best-case scenario. The generic bottom-up approach results in limited, but more detailed, coverage which makes the results conservative estimates for the application potential of HTHPs in German industries. The most energy-intensive sub-sectors of the German food and beverages industry are sugar production, meat processing, dairy processing, bakery products production and beer production, which together accounted for approximately 9333 kt-CO2-equivalents in 2020. The processes dominating the thermal energy demand are mainly pasteurisation, cooking, baking, evaporation, and drying processes, which require higher temperatures for the evaporation of liquids and boiling off bacteria. The thermodynamic efficiency, the COPs, of applying HTHPs to the processes lay between 1,7 – 4,8 for the worst-case scenario and 2,4 – 22,7 for the best-case scenario. The technical potential for 2018 results in 12 TWh. Between 3 - 5,5 TWh of electricity are required to cover the technical potential. The GHG emissions abatement potential lays between 52 - 855 kt-CO2-eq. This could mean a reduction of up to 9% of total GHG emissions of the five sub-branches. Due to very high electricity costs and an absent carbon tax in industry in 2018, the most cost-effective scenario (50 MW HTHP in the best-case) is not cost-competitive with the optimized fossil-fuel benchmark. The levelized cost of heat (LCOH) for this scenario is 37 €/MWh, of which approximately 67% are stemming from electricity costs. With a carbon tax of min. 48 €/t-CO2-eq. the switch to an HTHP becomes cost-competitive (incl. maintenance and investment costs). With an expected increase in carbon taxation, less efficient scenarios become cost competitive. By reducing the electricity price by 50%, the best-case scenario with the large HTHP is cost-competitive without a carbon tax. Hence, there is a strong correlation between electricity price and cost-competitiveness of HTHPs. It is expected that the emission factor of the German electricity mix will decrease further in the future and strive towards zero in the long-term, which will lead to substantial increase of GHG emissions abatement potential. When the emission factor for electricity is reduced by 38%, the GHG emissions abatement potential lays at 16% of total GHG emissions of the five sub-branches. The timely investment into HTHPs drastically reduces the risk of sunken costs and makes industrial decarbonisation efforts in this decade attractive from an industrial perspective. Subsidies, carbon taxation, and the reduction of electricity prices by for example removing the German renewable energy levy (EEG) can contribute to making low-carbon technologies such as HTHPs more competitive to fossil-fuel infrastructure that run on fossil fuels with low prices in the industrial sector. Industrial decarbonisation is highly relevant in Germany due to the recent tightening of industrial decarbonisation targets and the systemic demonstration of HTHPs potentials crucial to achieving the latter.","Industrial decarbonisation; process heat; high temperature heat pumps; techno-economic potential; GHG emissions abatement potential; carbon tax; German food and beverages industry; bottom-up approach","en","master thesis","","","","","","","","","","","","Industrial Ecology","",""
"uuid:25adc273-6d05-4a98-9319-be64d8e30bb8","http://resolver.tudelft.nl/uuid:25adc273-6d05-4a98-9319-be64d8e30bb8","Dynamic Characteristics of Industrial Heat Pump Operation: A modeling study","Hovenga, Nick (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Process and Energy)","Boersma, B.J. (mentor); Klein, S.A. (graduation committee); Pecnik, R. (graduation committee); Pourquie, M.J.B.M. (graduation committee); Otero Rodriguez, G.J. (graduation committee); Delft University of Technology (degree granting institution)","2021","In order to reach the goals of the Paris Agreement, global emissions must decrease at a high rate. Looking at the industrial sector, the largest share of energy is used for process heating, with fossil fuels as its primary source. A way to improve the energy efficiency and reduce the emissions of process heating is by the integration of heat pump technology.
However, operational costs are still a limiting factor in the widespread uptake of this technology. A potential of industrial heat pumps that will have a positive effect on the operational costs, as well as its general applicability, is the possibility to operate the equipment in a flexible manner. At this point, the potential to respond with high temperature industrial heat pumps to heat demand, the electricity market or to grid congestion, is not yet unlocked.
The focus in this study is on gaining more insight into the dynamic characteristics of industrial heat pump operation. The approach is based on the modeling of a 2 MW high temperature industrial heat pump in the Dymola simulation environment. Based on the system dynamics, a suitable control method is selected and the controller settings are optimized. With this control system in place, the dynamic limitations are studied.
The limiting factor in the considered economizer based heat pump cycle is the ability of the control system to keep the superheat at the screw compressor injection port within acceptable limits during load level changes. The heat pump is found to be able to ramp up and down at a maximum rate of approximately 20%/min. This level of flexibility allows use of the heat pump for both heat demand and electricity price response, as well as for participation in grid load balancing pools. On a higher level, based on these results flexible heat pump operation can be considered possible.","Industrial heat pump; Dynamic modeling; Flexibility","en","master thesis","","","","","","","","","","","","","",""
"uuid:b60dabb5-a018-4e79-a8ac-24fb2a02d376","http://resolver.tudelft.nl/uuid:b60dabb5-a018-4e79-a8ac-24fb2a02d376","Solar-assisted ground-source heat pump solutions for Dutch terraced houses: Investigation and modelling of SAGSHP technology as an alternative to traditional gas heating systems","Tarantini, Daniele (TU Delft Mechanical, Maritime and Materials Engineering)","Infante Ferreira, C.A. (mentor); Delft University of Technology (degree granting institution)","2021","In the last decades, the excessive increase in average global temperature related to a massive rise in greenhouse gas emissions showed the world how the fossil fuel society we live in today is drastically modifying and destroying the world we live in and is turning it in an un-habitable planet. Scientist all over the world made it clear that if we stay on the current patterns and we don't reduce drastically our greenhouse gas emissions, we are gonna end up with the extinction of the human species. The urgency of the problem seems to be clear to most people, what we need now are immediate actions to drastically reduce our greenhouse gas emissions. Among all different sectors, the residential sector is one of the biggest contributors to greenhouse gases (GHG) emissions and most of the energy is used for space heating (SH) and electrical appliances. In the specific case of the Netherlands, most energy provided to the residential sector is produced by means of natural gas, and the goal of the country is to replace natural gas with net-zero CO2 solutions. In this thesis work, a solar-assisted ground-source heat pump (SAGSHP) system for space heating for a typical Dutch terraced house is thoroughly investigated. In particular a 115 m2 house with 3 people living in it. The main different components of the system are investigate by looking at the state-of-the-art technology to understand what are the different system components that would be more convenient to use in the Netherlands in terms of efficiency, costs, etc. After the different system components have been selected and a general layout of the system is determined, the different components are designed and modelled using Matlab or Simulink environment. Finally, the whole system is assembled together and simulated in a Simulink environment. The simulation runs over a period of one year using a simulation time step of 6 minutes (0.1 hours). In particular two different cases have been used for the simulation. The base case used is an year where the ambient conditions used (ambient temperature and irradiance intensity) are values averaged over a period of twenty years (1991-2020). The second case is the simulation of a very cold year to see how the system performs in extreme cases. The simulated year is the year 2010. The obtained results are presented and discussed to draw conclusions and future work recommendations. The final goal of this work is to understand the competitiveness of the system with respect to a traditional gas boiler in terms of CO2 emission reduction, performance and costs. From this work it was possible to conclude that the chosen SAGSHP system performs slightly better in colder climates where a higher heat load requirement is needed. From the base case study used in this work, it was concluded that the modelled SAGSHP system can achieve a system seasonal coefficient of performance (SSCOP) of about 3.8 and it can significantly reduce the amount of CO2 emissions generated, up to about 2.8 ton of CO2 every year. From an economical point of view, the system levelized cost of energy (LCOE) is still higher than the LCOE of a traditional gas boiler system due to the high initial investment associated with SAGSHP systems.","SAGSHP; Solar-assisted ground-source heat pumps; modelling; MATLAB; Matlab Simulink","en","master thesis","","","","","","","","","","","","","",""
"uuid:47a374cf-f9d1-4fea-a5b9-6f51391ebf81","http://resolver.tudelft.nl/uuid:47a374cf-f9d1-4fea-a5b9-6f51391ebf81","Assessing the Operation of Typical Dutch Distribution Systems with Large Penetration of Low-Carbon Energy Technologies","Verhoeven, Gijs (Eindhoven University of Technology); Vergara Barrios, P.P. (TU Delft Intelligent Electrical Power Grids); Kok, Koen (Eindhoven University of Technology)","","2021","Currently, the majority of the available test feeder models are based on the North American type of distribution systems, leaving an absence of representative feeder models for the European (and Dutch) types of distribution systems. Therefore, a standardized set of power flow models for typical Dutch LV distribution networks is developed using real networks and operational data provided by a Dutch DSO. These network models are used to assess if typical Dutch LV distribution networks are ready to operate with large penetration of low-carbon energy technologies (e.g. PV systems, electric heat pumps, EVs). According to the obtained results, simulations of all the modelled networks showed the same behaviour for the power flow at the head of the distribution system and the voltage magnitude level. The changes in voltage magnitude however is dependent on the size of the network, resulting in larger changes in the larger networks. While the voltage magnitude level of the smaller networks stays within the ± 10% range, the larger networks encounter voltage magnitude violations. Thus, it can be concluded that the larger networks are not ready (under the current conditions) for large penetrations of low-carbon energy technologies, while the smaller networks appear to be ready.","power distribution control; distribution networks; distributed power generation; photovoltaic power systems; heat pumps; power grids; load flow","en","conference paper","","","","","","","","","","","Intelligent Electrical Power Grids","","",""
"uuid:bbe857d3-94fa-435c-a268-0c53fbe9db40","http://resolver.tudelft.nl/uuid:bbe857d3-94fa-435c-a268-0c53fbe9db40","Heat pump assisted drying of flower bulbs","Wagenaar, S. (Student TU Delft; Wagenaar Koeltechniek); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","","2021","Within the agriculture sector, drying of food and flowering products is a required production step. Most companies use hot air dryers where the heat is obtained by combustion of natural gas. This paper proposes a heat pump assisted drying system as an alternative. Flower bulb carrying boxes containing just harvested products have been approximated as packed beds filled with spherical products. A heat pump is proposed which includes a cross flow heat exchanger and allows for recirculation of the drying air while maintaining its operating temperature and humidity at optimal conditions to guarantee the required drying rate while preventing damage of the product. Simulink is used to optimize the operating conditions of the system guaranteeing both the product quality and a low energy consumption. The heat pump has been sized to dry 10 flower bulb carrying boxes of about 800 kg each in 24 hours. The performance of the heat pump (170 kWh/day renewable electricity) is compared to the performance of conventional fossil fuel based drying systems (350 kWh/day fossil fuel). Understanding heat and mass transfer mechanisms during drying allows optimization of the heat pump design.","Heat pump; Drying of horticulture products; Moisture removal; Experimental drying rates","en","conference paper","IEA","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:12a694b6-4514-4e91-b29f-73676d900caf","http://resolver.tudelft.nl/uuid:12a694b6-4514-4e91-b29f-73676d900caf","Seasonal thermal energy storage for large scale district heating","Remmelts, J.J.R. (Student TU Delft); Tensen, S.C. (Eneco Industrial & Heat); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","","2021","Seasonal thermal energy storage (STES) systems in combination with heat pumps can significantly reduce the impact of peak loads in large scale district heating systems and allow for the application of renewable heat sources in these networks. This paper investigates technologies with the highest potential for implementation in large scale district heating networks and identifies high temperature aquifer thermal energy storage (HT-ATES) as the most suitable technology. The HT-ATES has been applied at the primary side of the network (90 to 110 oC) and at the secondary side (72 to 92 oC). Suitable locations for the STES have then been identified. A control volume approach is used in Matlab to predict heat transfer and pressure drop in the HT-ATES wells considering porosity, permeability, grain size and geometry of the aquifer. The temperature distribution and extraction temperature are predicted as function of time. The yearly heating demand of a network has been used in combination with different operating modes to identify the required size of the HT-ATES. The simulations indicate that it will take 5 years to reach steady temperature supply.","Heat pump; High temperature aquifer energy storage; District heating","en","conference paper","IEA","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:f41ad100-4962-4f43-8475-8e888f488370","http://resolver.tudelft.nl/uuid:f41ad100-4962-4f43-8475-8e888f488370","Heating system based on heat recovery from sewage","Avadhani, M. (Student TU Delft); van Rooyen, Roland (City of Rotterdam); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","","2021","Buildings consume 40% of the total global energy and contribute to over 30% of all CO2 emissions. Space heating forms a significant part of energy consumption in buildings. A possible solution is to recover waste heat from sewage and to upgrade its exergy using a heat pump. Polymers reduce cost and energy required for manufacturing the heat exchangers. The impact of sewage flow and temperature, heat exchanger dimensions and thermal enhancement of polymers on heat recovery is studied using a Matlab model. The model integrates a sewage heat exchanger with a heat pump and optimizes heat recovery from sewage. A heat pump is used to obtain hot water at 55°C for space heating. Heat recovered from sewage and overall COP are quantified. In case of HPDE with graphite filler, increase in filler content from 0% to 30% increases thermal conductivity from 0.46 to 1.89 Wm-1K-1 increasing the heat recovery with 34%. The heat transfer coefficient becomes twice as large when polymer with no filler is enhanced with 30% filler content. Large heat exchange area and variability of sewage level limit the recovered heat.","Enhanced polymer; Sewage heat recovery; heat pump; Building heating systems","en","conference paper","IEA","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:2685f344-1b1f-4171-b41f-cf40010bf96b","http://resolver.tudelft.nl/uuid:2685f344-1b1f-4171-b41f-cf40010bf96b","Low temperature district heating based on low temperature geothermal heat (30 oC)","Knepper, S. (Student TU Delft); Pothof, I.W.M. (TU Delft Support Process and Energy; Deltares); Itard, L.C.M. (TU Delft Building Energy Epidemiology); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","","2021","A comparative study for a representative case district in the Netherlands with around 2500 dwellings has been executed with the purpose of identifying the best solution for a Low Temperature District Heating (LTDH) with Low Temperature Geothermal Heat (LTGH) as the main heat source. The district is presently connected to the Dutch gas network. Its heat demand and building typologies are used as departing points. The comparison is based on 3 key performances indicators (KPI’s): CO2 emissions, levelized costs of energy (LCOE) and peak electricity use. The following LTDH designs have been considered: Central heat pump and collective peak supply at 70 ⁰C / 50 ⁰C; Central heat pump and decentral peak supply at 70 ⁰C / 50 ⁰C; Decentralized heat pumps using 30 ⁰C supply temperature. Individual air source heat pumps for space heating and electric boilers for domestic hot water purposes are taken as reference. The LTDH concept with decentralized heat pumps saves 19.5 %, 16.8 % and 36 % on the CO2 emission, LCOE, and electricity use in peak load hours compared to the reference concept.","Heat pump; Low temperature district heating; Low temperature geothermal heat source","en","conference paper","IEA","","","","","","","","","","Support Process and Energy","","",""
"uuid:08e16a9e-e8f7-41a1-be55-aa1285a6ecdf","http://resolver.tudelft.nl/uuid:08e16a9e-e8f7-41a1-be55-aa1285a6ecdf","Analytical model for arbitrarily configured neighboring shallow geothermal installations in the presence of groundwater flow","Al-Khoury, Rafid (TU Delft Applied Mechanics); BniLam, Noori (Universiteit Antwerpen); Musivand Arzanfudi, M. (TU Delft Applied Mechanics; DIANA FEA); Saeid, S. (TU Delft Reservoir Engineering)","","2021","This paper introduces an analytical model analyzing the effect of groundwater flow on heat transfer in an infinite conductive-convective porous domain representing shallow geothermal systems with arbitrarily configured cylindrical heat sources. The model is formulated based on the moving source concept and solved based on the spectral analysis method and the superposition principle. Compared to models based on the Green's function and the Laplace transform, the proposed spectral model has a simpler formulation, computationally efficient and easy to implement in computer codes. It can handle random time-dependent thermal loads and any arbitrarily configured grid distribution. The verification and numerical examples demonstrate the computational capabilities of the model, and show how the groundwater flow can play an important role in the thermal interaction between heat sources. They also feature how to make use of the direction of groundwater flow to avoid undesirable thermal interaction between neighboring installations, rapid depletion of energy sources and unfair mining of geothermal energy.","Conduction-convection heat flow; Heat flow due to groundwater; Moving cylindrical heat source; Neighboring ground source heat pump installations","en","journal article","","","","","","","","","","","Applied Mechanics","","",""
"uuid:5026a9fb-369c-4241-a5e8-ff1c0c132194","http://resolver.tudelft.nl/uuid:5026a9fb-369c-4241-a5e8-ff1c0c132194","Prediction of stirling-cycle-based heat pump performance and environmental footprint with exergy analysis and lca","Khan, Umara (Åbo Akademi University); Zevenhoven, Ron (Åbo Akademi University); Stougie, L. (TU Delft Energie and Industrie); Tveit, Tor Martin (Olvondo Technology)","","2021","The use of Stirling-cycle-based heat pumps in high-temperature applications and waste heat recovery at an industrial scale is of increasing interest due to the promising role in producing thermal energy with zero CO2 emissions. This paper analyzes one such technology as developed by Olvondo Technology and installed at the pharmaceutical company AstraZeneca in Sweden. In this application, the heat pump used roughly equal amounts of waste heat and electricity and generated 500 kW of steam at 10 bar. To develop and widen the use of a high-performance high-temperature heat pump that is both economically and environmentally viable and attractive, various analysis tools such as exergy analysis and life cycle assessment (LCA) can be combined. The total cumulative exergy loss (TCExL) method used in this study determines total exergy losses caused throughout the life cycle of the heat pump. Moreover, an LCA study using SimaPro was conducted, which provides insight into the different emissions and the overall environmental footprint resulting from the construction, operation (for example, 1, 8, and 15 years), and decommissioning phases of the heat pump. The combined results were compared with those of a fossil fuel oil boiler (OB), a bio-oil boiler (BOB), a natural gas-fired boiler (NGB), and a biogas boiler (BGB).","Exergy analysis; Life cycle assessment (LCA); Stirling-cycle-based heat pump; Sustainability; Total cumulative exergy loss (TCExL)","en","journal article","","","","","","","","","","","Energie and Industrie","","",""
"uuid:20e231dc-5df4-48b5-b1e2-b8c3cb4752f2","http://resolver.tudelft.nl/uuid:20e231dc-5df4-48b5-b1e2-b8c3cb4752f2","The Pavilion Roof: Modular Roof-System for Sustainable Household Provision","de Jonge, Linde (TU Delft Industrial Design Engineering; TU Delft Sustainable Design Engineering)","Faludi, J.J. (mentor); Kroon, C.P.J.M. (graduation committee); Delft University of Technology (degree granting institution)","2020","This report contains the graduation project of Linde de Jonge in collaboration with Paviljoen 3, and aims to find a solution to reducing the eco-footprint of existing homes, by combining solar panels, green roofs and heat pumps in a modular fashion to be adaptable to the specific requirements of each household and complement the working of each individual system. Method User research, market analysis, creative sessions and observational studies have been implemented to support the iterative process towards a solution. The creative process was divided in three cycles. The focus of the first cycle was to find a solution with high feasibility for the company, by combining products on the market and adding small but crucial design intervention to create a unified system for flat roof surfaces. The second cycle aimed to create a solution suitable for tiled roofs, which is exceedingly common in the Netherlands, yet thus far incompatible with a green roof. The focus was on creating a solution which would enhance the exterior of the building, to increase the desirability of the design (an opportunity based on client research). The two cycles resulted in two concepts with a very opposing solution approach. These concepts were presented to the company and a selection was made. This selected concept was the start of the third cycle. In this cycle, the feasibility is established by detailing the embodiment of the system. Furthermore, the viability is illustrated by a future development roadmap. Design This project’s main challenge can be summarized as finding the balance between: 1. introducing an entire roof-system to market; 2. without losing the flexibility in the wide range of products (PV, heat pump or green roof) available to fit the variance in client and household needs; 3. and with the least amount of in-house produced parts to fit the company’s resources. The solution of this project is an entire roof-system, consisting of market available components and components proposed to be developed and manufactured by the company Paviljoen 3, which are implemented into the system according to distinct development phases. By combining existing products on the market, solely introducing components which are crucial for the viability of the roof-system and separating the innovation of system’s components into separate phases, this solution diffuses the investment costs for P3, while enabling them to acquire empirical insights concerning the system, which they can apply in further system development. They can have intensive prototyping and experience using market-bought products, before they invest in launching their own product. The design cycle ends with a final prototype of the developed components, and a company evaluation. The report concludes with a list of recommendations for the company to pursue further concept development.","Sustainable; Roof-system; Solar panels; Green roof; Heat pump","en","master thesis","","","","","","","","","","","","Integrated Product Design","",""
"uuid:874e838c-f6e4-4f72-9a07-b4b5fcf90f79","http://resolver.tudelft.nl/uuid:874e838c-f6e4-4f72-9a07-b4b5fcf90f79","Assessing the Demand Response Potential of Heat Pumps in All-Electric Buildings Equipped with PV, EV, and BES to Minimize Energy Costs","Gaona Reinoso, David (TU Delft Electrical Engineering, Mathematics and Computer Science; TU Delft DC systems, Energy conversion & Storage)","Chandra Mouli, G.R. (mentor); Delft University of Technology (degree granting institution)","2020","In the residential sector, natural gas has been the main consumed energy resource for surface heating (SH) and domestic hot water (DHW) during cold seasons, and substituting this energy carrier with electricity from renewable resources imposes challenges not only in economic but also technical terms. Due to the intermittent nature of renewable sources, the electricity production will fluctuate causing a mismatch between the electricity supply and demand. Therefore, this fluctuation in the electricity supply must be mitigated to prevent instability in the transmission and distribution grids. In this context, the integration of flexible energy devices such as heat pumps (HP), electric vehicles (EV), and batteries (BES) within demand response programs present as a promising option to reduce the effects of intermittent electricity production from renewable resources for the residential and transportation sectors. In this thesis, an integrated energy system formed by PV panels, EV, BES, and a HP coupled with thermal storage tanks (TES) has been studied. The research aimed to minimize the total energy costs by scheduling the optimal power consumption of each device using a demand response program based on electricity price signals. This control scheme allowed to determine the optimal energy consumption of the HP and its flexibility potential. This has been achieved by developing a HP-TES model to satisfy the SH and DHW demands of a typical Dutch household. Then, the HP-TES model was implemented into a second model developed by Wiljan Vermeer and Gautham Ram which described the functioning of the PV-BES-EV systems. With this, an NLP optimization problem to minimize the total energy costs of the all-electric system was formulated and solved in GAMS. Three different scenarios were studied: a base case where no demand response program is used, a demand response case with a high feed-in tariff (FIT), and a demand response case with a reduced FIT. The HP coupled to a TES produced a load shifting potential, where its power consumption was optimally scheduled to happen at times of low electricity prices to charge the storage tanks. Thus, at times of high electricity prices, the HP remained OFF and the thermal demand of the building was entirely met by the storage system. It was calculated that the HP did not operate for 9.45 h/per day during 5 days in winter season, shifting in total 56 kWh of energy towards low demand times. Finally, it was found that in the high FIT scenario, the system’s strategy to minimize the energy costs consisted of purchasing and injecting energy at low and high prices, respectively. It was calculated that a 49% in cost savings could be achieved in this scenario compared to the base case. On the other hand, in the reduced FIT case, the system’s energy intake was reduced, and no energy was injected to the grid, resulting in 44% in cost reduction.","Heat pumps; Demand Response; Thermal energy storage; Renewable Energy Integration; Cost minimisation; V2G","en","master thesis","","","","","","","","","","","","Electrical Engineering | Sustainable Energy Technology","",""
"uuid:cc6633ee-44bd-47a0-9b05-72449f4029f4","http://resolver.tudelft.nl/uuid:cc6633ee-44bd-47a0-9b05-72449f4029f4","Experimental Validation of Wet Compression with a Twin Screw Compressor Prototype","Kothari, V.V. (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Process and Energy)","Infante Ferreira, C.A. (mentor); Delft University of Technology (degree granting institution)","2020","Decarbonisation can be done through various routes: reducing the final energy consumption by improving process conditions and efficiency, reusing waste heat and by an outright energy transition to renewable sources. In this study, the focus is on reusing waste heat. Heat pumps have the potential to drastically reduce energy requirements in the industry and in that way reduce emissions (Kiss and Infante Ferreira, 2017). van de Bor et al. (2015) compared different heat pump technologies and for industrial applications where there is a temperature glide of the heat source and/or sink compression-resorption heat pumps (CRHP) utilizing wet compression can achieve a higher coefficient of performance (COP) than alternative technologies. However, an isentropic efficiency of 70% for the compressor was assumed. If this limit is not reached there might be no advantage of wet compression compared to the traditionally used vapour compression heat pump (VCHP) as pointed out by several authors (Itard and Machielsen (1994), and Zaytsev (2003)). This study consists of experimental and modelling aspects. The compressor model is experimentally validated in this thesis. Deep knowledge about relevant topics like wet compression, compressor specifications, thermodynamic and geometrical models is developed before starting off with the experiments. The experiments are carried out for four rotational speeds: 10320 rpm, 12910 rpm, 14205 rpm and 15500 rpm, taking system constraints into account. Two approaches are considered here: the homogeneous approach and the heterogeneous approach. In the homogeneous approach, the concentration of ammonia is constant across the compressor and the process medium is treated as a single entity. In the heterogeneous approach, an assumption is made: only the vapour is compressed whereas the liquid exchanges heat with the vapour leading to partial evaporation. The model developed is updated. The experimental and model results are then validated and conclusions are drawn.","Wet compression; twin screw compressor; Experimental; Heat pump; compressor","en","master thesis","","","","","","","","","","","","","",""
"uuid:f5dd1a15-d66d-4fc9-b2cf-15129c6c2800","http://resolver.tudelft.nl/uuid:f5dd1a15-d66d-4fc9-b2cf-15129c6c2800","Investigating Hidden Flexibilities Provided by Power-to-X Considering Grid Support Strategies","Yağci, Caner (TU Delft Electrical Engineering, Mathematics and Computer Science)","Cvetkovic, M. (mentor); Delft University of Technology (degree granting institution)","2020","Highly volatile nature of renewable energy sources (RES) has increased the demand for flexibility in electrical power systems. Electrification of the industry with power-to-X (PtX) technologies is one of the most promising ways to increase energy system flexibility since industry accounts for the largest share of the world’s total energy demand. However, flexibilities provided by power-to-X models can be concealed in the simulation results due to modelling approximations. Therefore, PtX modelling must be analyzed with respect to the requirements of flexibility analysis. Additionally, the planning and operation of such multi-energy system (MES) needs to be coordinated to use the available resources (RES & PtX) optimally. Thus, a comprehensive energy management approach must be provided for MES.This study investigates the impact of model fidelity of PtX devices in flexibility analysis. Additionally, impact of hierarchical energy management system to optimally control the flexibility dispatch is investigated. First, a realistic case study is developed for multi-energy system to investigate energy system flexibility. Secondly, power-to-gas and power-to-heat models are developed in OpenModelica, and the effect of operational temperature simplifications of PtX models on flexibility analysis is investigated. Lastly, using co-simulation, PtX models are combined with Pandapower optimal power flow solver for the optimal deployment of flexibility.The findings of this study have provided a deeper insight into multi-energy system flexibility. The investigation of hidden flexibility has revealed that precision of flexibility analysis is bounded by the efficiency characterization of PtX, and correct efficiency characterization of PtX highly depends on operating temperature conditions. The study also shown that, a comprehensive control approach can be achieved by agent-based hierarchical energy management system and this new understanding may help to improve predictions for the optimum operation point of MES.","Multi-energy system; energy flexibility; power-to-X; hierarchical control; optimal power flow; co-simulation; electrolyser; heat pump","en","master thesis","","","","","","","","","","","","Electrical Engineering | Electrical Power Engineering","",""
"uuid:d4d8a46b-08ba-4c3d-9e28-6ff40c662fa5","http://resolver.tudelft.nl/uuid:d4d8a46b-08ba-4c3d-9e28-6ff40c662fa5","The influence of freezing-thawing cycles on the geotechnical performance of an end-bearing energy pile","Snoeren, Jasper (TU Delft Civil Engineering and Geosciences)","Vardon, Phil (mentor); de Nijs, Richard (graduation committee); Copuroglu, Oguzhan (graduation committee); van Dorst, Renée (graduation committee); Delft University of Technology (degree granting institution)","2020","Energy piles are getting more attention for their sustainable and economic potential. The fluid pipes are integrated in the foundation piles, which makes it cost-attractive, but also relatively new to the Dutch geotechnical industry. By lowering the temperature limit of the anti-freeze fluid in the pipes the heat extraction and thereby also the necessary pile length can be optimized. However, the resulting thermal loads might influence the structural function and are therefore a main obstruction for the industry. Within this thesis three aspects of freezing-thawing of an axially compressed end-bearing energy pile are evaluated: (i) frost resistance of concrete, (ii) thermal analysis and (iii) geotechnical analysis. The objective is to work towards a conclusion on the degradation effects of freezing-thawing processes along the edge of an end-bearing energy pile and come up with practical advice for the design. The behaviour of the concrete is evaluated by literature, wherein the concrete thermal conductivity and mixture are key elements. For the thermal analysis a pile group simulation and a detailed single pile analysis is performed in Comsol Multiphysics. The soil stratigraphy is simplified and based on the Western part of the Netherlands. The input originates from the heat-cool demand of a single household related to the monthly gas usage in the Netherlands. Typical heat extraction for this specific case, i.e. long-term average amount of 7 W/m, for 7 years did not result in freezing temperatures at the edge of the most critical piles. Freezing occurred after an increased heat extraction until 10 W/m. Furthermore, the influence of daily cycles in the single pile analysis damped by the thermal resistance of the concrete pile. The geotechnical analysis is assessed in an axisymmetric model in Plaxis with and without a fully-coupled thermo-hydro-mechanical (THM) module. The first set of analyses with THM examines the influence of expansion and contraction of materials including phase changes, but without changes in soil mechanical and physical properties. Two situations are considered that are different in terms of the position of their neutral plane and negative shaft resistance. The resulting settlements can be distinguished as initial structural load and settlements due to thermal seasonal cycles, which fluctuate between 1 mm. A ratcheting behaviour was observed and resulted in a settlement of 12 and 3 mm over 5 years. However, the volumetric strain accumulation around the pile indicates unrealistic results in the THM module and conclude that the simulation of freezing-thawing cycles has to be done in a more advanced constitutive model which can capture freezing-thawing behaviour of soils. Within the second set of analyses the impact of the soil strength and stiffness due to a freezing-thawing cycle was investigated for the two situations to determine their effect on the pile behaviour in terms of load-displacement and shear distribution. The results indicate that effective cohesion is most influencing the pile behaviour and it indicates that no need exist to change the design approach of end-bearing piles as long as the potential negative shaft resistance along the pile over all layers above the bearing layer is included in the design calculation and considered fully mobilized.","energy pile; Geothermal Energy; Ground source heat pump; Thermo-hydro-mechanical; Freezing-thawing; Concrete degradation","en","master thesis","","","","","","","","","","","","Geo-Engineering","",""
"uuid:ebf35354-7521-4a59-8347-c85a0982f3de","http://resolver.tudelft.nl/uuid:ebf35354-7521-4a59-8347-c85a0982f3de","Technical and economic analysis of wet compression–resorption heat pumps","Gudjonsdottir, V. (TU Delft Engineering Thermodynamics); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","","2020","Heat pumps can efficiently upgrade waste heat from the industry and in that way reduce emissions. One of the main reasons why heat pumps are not applied to a greater extent in industry are large payback periods. Compression–resorption heat pumps (CRHP) enhanced by wet compression are considered a very promising option that can have higher coefficient of performance compared to traditional technologies when the heat source and/or sink have a large temperature glide. In this study the thermodynamic and economic performance of two potential industrial cases are examined for CRHP operating with NH3–H2O and NH3–CO2–H2O. A detailed thermodynamic model of the compressor is used to evaluate the isentropic efficiency for each case. The results are used to calculate the simple payback period, when a boiler is replaced by a CRHP, as a function of the predicted gas and electricity prices in the Netherlands from 2020 to 2035. The results indicate that adding CO2 to the NH3–H2O mixture increases the cycle COP when the temperature glide of the heat sink is 40 K while the opposite occurs when the glide is 80 K. The highest COPs and lowest payback times are obtained when the outlet vapor quality is around 0.50 for both the binary and ternary mixtures. Larger glides require higher outlet qualities. However, it is clear that even for high temperature glides the payback period can be within acceptable limits, especially if the cost of CO2 emissions is taken into account.","High temperature heat pumps; NH-HO; NH–CO–HO; Technical and economic analysis; Twin-screw compressor","en","journal article","","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:36622fed-b99a-418b-8ff1-73aabfea6a5c","http://resolver.tudelft.nl/uuid:36622fed-b99a-418b-8ff1-73aabfea6a5c","Parameter identification algorithm for ground source heat pump systems","Bni Lam, N.H.N. (TU Delft Applied Mechanics; Universiteit Antwerpen); Al-Khoury, Rafid (TU Delft Applied Mechanics)","","2020","This paper presents a new parameter identification (PI) algorithm for estimating effective and detailed thermal parameters of ground source heat pump systems using data obtained from the well-known thermal response test. The PI comprises an iterative scheme coupling a semi-analytical forward model to an inverse model. The forward model is formulated based on the spectral element method to simulate transient 3D heat flow in ground source heat pump (GSHP) systems, and the inverse model is formulated based on the interior-point optimization method to minimize the system objective function. Compared to existing interpretation tools for the thermal response test, the proposed PI algorithm has several advanced features, including: it can handle fluctuating heat pump power and inlet temperatures; interpret data obtained from multiple heat injection or extraction signals; produce accurate backcalculation for short and long duration experiments; and handle multilayer systems. The PI algorithm is tested against synthesized data, using a wide range of random noise, and versus an available laboratory experiment. The computational results show that the PI algorithm is accurate, stable and exhibiting relatively high convergence rate.","Backcalculation of thermal properties; Borehole heat exchanger; Ground source heat pump; Parameter identification; Thermal response test","en","journal article","","","","","","","","","","","Applied Mechanics","","",""
"uuid:fe91b587-0447-4118-ba17-428c2969b205","http://resolver.tudelft.nl/uuid:fe91b587-0447-4118-ba17-428c2969b205","Experimental investigation of absorption in upward and downward flow of NH3-CO2-H2O in a mini-channel heat exchanger","Shi, Liang; Gudjonsdottir, V. (TU Delft Engineering Thermodynamics); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","","2020","Heat pumps can drastically reduce energy requirements in industry. Operating a compression resorption heat pump with an NH3-CO2-H2O mixture has been identified as a promising option that can have an increased performance compared to only NH3-H2O. In this paper an important process of the heat pump cycle is investigated: The absorption process. A mini-channel heat exchanger with 116 tubes of inside diameter of 0.5 mm is used for this purpose. For the NH3-H2O experiments overall heat transfer coefficients of 2.7–6 kW/(m2K) were reached for mixture mass flows of 0.71–2.5 kg/h. For the NH3-CO2-H2O mixture pumping instabilities limited the operating range which resulted in higher pressures and higher mixture mass flows compared to NH3-H2O. The overall heat transfer coefficients were lower in the case of the added CO2, with the maximum of 3 kW/(m2K) corresponding to a mixture mass flow of 4.2 kg/h. However, an increase in heat transfer of approximately 5% was reached with the added CO2 which is beneficial for heat pump applications. Additionally, limited research has been conducted on absorption in upward versus downward flow and, therefore, these two configurations have also been tested in the mini-channel heat exchanger. Even though the pumping instabilities vanished with absorption in upward flow it was confirmed that absorption in downward flow with the mixture on the tube side is the most beneficial configuration for absorption of ammonia in NH3-CO2-H2O or NH3-H2O in a mini-channel heat exchanger. The performance increased by approximately 10% with absorption in downward flow.","Heat pumps NH-CO-HO NH-HO absorption mini-channel heat exchanger","en","journal article","","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:b42b9e88-d083-4135-bf0e-e4142845a309","http://resolver.tudelft.nl/uuid:b42b9e88-d083-4135-bf0e-e4142845a309","Scalable distributed sensor fault diagnosis for smart buildings","Papadopoulos, Panayiotis M. (University of Cyprus); Reppa, V. (TU Delft Transport Engineering and Logistics); Polycarpou, Marios M. (University of Cyprus); Panayiotou, Christos G. (University of Cyprus)","","2020","The enormous energy use of the building sector and the requirements for indoor living quality that aim to improve occupants'productivity and health, prioritize Smart Buildings as an emerging technology. The Heating, Ventilation and Air-Conditioning ( HVAC ) system is considered one of the most critical and essential parts in buildings since it consumes the largest amount of energy and is responsible for humans comfort. Due to the intermittent operation of HVAC systems, faults are more likely to occur, possibly increasing eventually building's energy consumption and - or downgrading indoor living quality. The complexity and large scale nature of HVAC systems complicate the diagnosis of faults in a centralized framework. This paper presents a distributed intelligent fault diagnosis algorithm for detecting and isolating multiple sensor faults in large-scale HVAC systems. Modeling the HVAC system as a network of interconnected subsystems allows the design of a set of distributed sensor fault diagnosis agents capable of isolating multiple sensor faults by applying a combinatorial decision logic and diagnostic reasoning. The performance of the proposed method is investigated with respect to robustness, fault detectability and scalability. Simulations are used to illustrate the effectiveness of the proposed method in the presence of multiple sensor faults applied to a 83-zone HVAC system and to evaluate the sensitivity of the method with respect to sensor noise variance.","Fault diagnosis; HVAC; Buildings; Autoregressive processes; Analytical models; Heat pumps; Water heating","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-10-28","","","Transport Engineering and Logistics","","",""
"uuid:a7f05e8b-cf08-4923-b7a9-05ff817a50fc","http://resolver.tudelft.nl/uuid:a7f05e8b-cf08-4923-b7a9-05ff817a50fc","A spectral model for a moving cylindrical heat source in a conductive-convective domain","Al-Khoury, Rafid (TU Delft Applied Mechanics); Bni Lam, N.H.N. (Universiteit Antwerpen); Musivand Arzanfudi, M. (TU Delft Applied Mechanics; DIANA FEA); Saeid, S. (TU Delft Reservoir Engineering)","","2020","This paper introduces a spectral model for a moving cylindrical heat source in an infinite conductive-convective domain. This physical process occurs in many engineering and technological applications including heat conduction-convection in ground source heat pump systems, where the borehole heat exchangers likely go through layers with groundwater flow. The governing heat equation is solved for Dirichlet and Neumann boundary conditions using the fast Fourier transform for the time domain, and the Fourier series for the spatial domain. A closed form solution based on the modified Bessel functions is obtained for the Dirichlet boundary condition and an integral form for the Neumann boundary condition. Limiting cases of the moving cylindrical heat source to represent a moving line heat source are also derived. Compared to solutions based on the Green's function and the Laplace transform, the spectral model has a simpler form, applicable to complicated time-variant input signals, valid for a wide range of physical parameters and easy to implement in computer codes. The model is verified against the existing infinite line heat source model and a finite element model.","Conduction-convection heat flow; Ground source heat pump; Heat flow in groundwater; Moving cylindrical heat source","en","journal article","","","","","","","","","","","Applied Mechanics","","",""
"uuid:b02ca317-8855-48b7-9e3f-7215ed63641f","http://resolver.tudelft.nl/uuid:b02ca317-8855-48b7-9e3f-7215ed63641f","Potential of polymer sewage heat exchangers with enhanced thermal properties","Avadhani, Maneesh (TU Delft Mechanical, Maritime and Materials Engineering)","Infante Ferreira, Carlos (mentor); Delft University of Technology (degree granting institution)","2019","Buildings contribute to 30% of global CO2 emissions and consume 40% of the global energy supply (Yang et al., 2014). Heating and cooling requirements of the buildings form the major part of the energy consumption in buildings (Culha et al., 2015). Thus to solve this problem, one of the solutions currently being
looked at is to recover heat from the sewage. Cities have large sewage flows and in the winter the sewage is warmer than ambient and in the summer it is colder than the ambient, thus making it a good heat source and sink respectively. This work involves the integration of waste water heat exchanger with heat pump
to form a Waste Water Source Heat Pump (WWSHP). This system was further integrated with Aquifer Thermal Energy Storage (ATES) system. The WWSHP system was modeled in Matlab and the aquifer was modeled in COMSOL. COMSOL Live-link Matlab feature was used to integrate the two models.
Polymers were chosen as heat exchanger material due to their low cost, low weight (lower CO2 emissions during transportation), flexibility, non corrosive nature and low energy requirement in manufacturing (Hussain et al., 2017). Two systems were proposed to support the heating and cooling demands of the concert venue and convention centre of the Rotterdam, the ’Doelen’. The objective of this work was to illustrate the potential of polymer sewage heat exchangers. The first system was called the WWSHP system. In this system, heat was recovered from the sewage in the winter through polymer heat exchangers and was upgraded in a heat pump for use in the heating network of the ’Doelen’. The heat pump was a reversible one, thus, in the summer, heat was extracted from the cooling network of the ’Doelen’ and rejected to the sewage through the same polymer heat exchangers. To obtain more heat in the winter, a second system was proposed. This system was called WWSHP + ATES system. In this system, heat was extracted from the sewage and an aquifer. This extracted heat was upgraded in a heat pump for supply to the ’Doelen’. In the summer, the heat extracted from the ’Doelen’ along with the heat recovered from the sewage were used to refill the warm well of the aquifer to maintain thermal balance. The scope of the work also included optimizing the dimensions, material and cost of the waste water heat exchanger. In both the systems, the summer and the winter models were different, hence they were simulated separately. The heat recovery model was built based on a sewage channel near the ’Doelen’. The sewage channel data and the sewage flow and temperature data were provided by the Gemeente of Rotterdam. The waste wa-ter heat exchanger was chosen to be a multi row tube polymer heat exchanger. Various polymer options were available, among which the option with the highest thermal conductivity, High Density Poly-ethylene (HDPE) was chosen. Among six combinations of standard HDPE tube lengths and diameters, tube length of 30 m and tube inner diameter of 29 mm were found to be the most optimum in terms of economics and heat recovery. Based on the optimized tube dimensions, heat delivered by the system to the ’Doelen’ per unit cost was compared for different materials and the results confirmed that HDPE with a cost of 0.54 €/kg was the best choice. Thus, using the optimized combination of tube dimensions and HDPE as tube material, 374 MWh of heat was recovered from the sewage in the winter and 486 MWh of heat was supplied to the heating network of the ’Doelen’ through the heat pump. In the summer, 23 MWh was removed from the ’Doelen’ by the heat pump and 26 MWh was rejected to the sewage using the same HDPE heat exchangers. Among the different polymer and filler combinations, PE (Polyethylene) with 30% graphite filler was foundto be the best choice. Using PE with 30% graphite resulted in 32% higher heat recovery from the sewage in the winter and 15% higher heat rejection to the sewage in the summer when compared to HDPE with no fillers. Thermal enhancement of polymer tubes, although increased the amount of heat exchanged with the sewage in the winter and the summer, it reduced the system economic performance (kWh/€) in the winter.
The WWSHP + ATES system supplied 1244 MWh of heat to the ’Doelen’ in the winter and removed 388 MWh of heat from the ’Doelen’ in summer. Furthermore, thermal enhancement of polymers of the waste water heat exchangers reduced the performance (kWh/€) of the WWSHP+ATES system in both the summer and the winter. WWSHP + ATES system proved to be capable of handling higher heating and cooling demand than the WWSHP system. The costs of heat exchangers and electricity were also much higher for this option, thus making it less economical. For instance, the WWSHP model supplied 66 kWh to the ’Doelen’ per € spent, as opposed to the WWSHP + ATES system which supplied only 34 kWh/€. Thus, only high heating and cooling requirements would justify the use of WWSHP + ATES system.","Polymers; Waste heat recovery; ATES; Sewage; Heat exchanger; Waste water source heat pump; Heat pump","en","master thesis","","","","","","","","","","","","Mechanical Engineering","",""
"uuid:8b1d99a0-eda0-4efc-b519-04ae1e695079","http://resolver.tudelft.nl/uuid:8b1d99a0-eda0-4efc-b519-04ae1e695079","Assessment of machine learning algorithms for the purpose of heat pump detection based on load profiles and temperature readings","Francica, Roberto (TU Delft Electrical Engineering, Mathematics and Computer Science)","Tindemans, S.H. (mentor); van Westering, Werner (mentor); Delft University of Technology (degree granting institution)","2019","The aim of this research thesis is to use machine learning models to distinguish owners of heat pumps from non-owners of heat pumps based on load profiles and temperature data only. As is the case with data mining project, its workflow can be divided into business understanding, data gathering, analysis, modeling and interpretation and deployment. As of the time of the time of this writing the models have not yet been deployed. The necessity to conduct this master thesis arises from the growing popularity of heat pumps in the Netherlands, and the potential issues associated with this spread on management of low-voltage distribution grids, in particular the rising electricity demand in the heating season. Before such issues can be analyzed however, the number of all heat pump users needs to be determined. This master thesis aims in determining precisely the overall number of heat pumps users by examining individual load profiles.
Data available for the purpose of thesis consists of load profiles of owners and non-owners of heat pumps provided by Alliander, load profiles of London-based non-owners of heat pumps, referred to as baseload profiles, load profiles of heat pumps only spread across the UK, temperature records for De Bilt in the Netherlands, London and Nottingham. The above-mentioned data was cleaned and manipulated before features were extracted from it. In particular, synthetic load profiles of heat pump owners were created by pairing baseload profiles with the pump only load profiles. Next all load profiles were normalized in order to diminish the importance of confounding variables, more on that later, and only night-hours were kept so as not to account for PV production. Such normalized load profiles were paired up in two sets: Alliander's set which consisted of load profiles of heat pump owners and non-owners provided by Alliander and simulated set which consisted of baseload profiles and synthetic load profiles of heat pump owners. It is worth mentioning that a confounding variable was present in Alliander's set, mainly the size of house since owners of heat pumps all lived in single standing houses as compared to non-owners, majority of whom lived in apartments.
Subsequently, the following four features were extracted from normalized night-time load profiles within each two sets: (1) average daily electricity consumption in January and December (this period is also referred to as winter or heating period), (2) ratio of average daily electricity consumption in January and December to average daily electricity consumption in July and August (it is also referred to as summer or cooling period), (3) slope of the curve representing mean daily temperature on x-axis and daily electricity consumption in y-axis, and lastly (4) coefficient of determination of curve representing mean daily temperature on x-axis and daily electricity consumption in y-axis.
Three main evaluation criteria were set for the performance of machine learning models: True Negative Rate, True Positive Rate and Precision. For simplicity, the mean score was used as well, which is equal to the average of True Positive Rate, True Negative Rate and Precision. Benchmark for all evaluation metrics was set to 90\%. Five models that were used to distinguish heat pump owners from non-owners were Logistic regression, Decision Tree and Support Vector Machines with Linear, Polynomial and Radial kernels. The evaluation procedure was the following: first hyperparameters for all the five models were tuned by using 10-fold cross validation with test and training set being features extracted from Alliander's set only. Next, the models with optimal hyperparameters were trained on features extracted from Alliander's set and tested on features from simulated set.
The results show that none of the models managed to reach the benchmark of triple 90\% for True Positive Rate, True Negative Rate and Precision. In the hyperparameter tuning stage both True Negative Rate and True Negative Rate were close to reaching 90\%, however, this has been achieved at the cost of low Precision, reaching just above 50\%. This was the case due to the propensity of the models to commit type I error, that is false positives. On the other hand, at the evaluation stage when the simulated set-features served as test set, it was noticed that precision was at a significantly higher level, approximately 75\%, which came at a cost of lower True Positive Rate, around 50\%. True Negative Rate though did exceed 90\%. These results show a strong tendency of making type II error, that is false negatives. The best performing model, which was the Support Vector Machine with Radial Kernel, achieved a mean score of 75\%.
The divergence of results from the hyperparameter tuning stage to the evaluation stage is caused by the fact that there are different usage patterns of heat pumps between the owners of heat pumps in Alliander's load profiles and in the synthetic load profiles of heat pump owners. Particularly it is the case that owners of heat pumps in Alliander's set, do use heat pump in the night, as compared to synthetic users, which do so to a much smaller extent. As a result the features extracted from the simulated set of load profiles are less indicative of heat pump ownership than the features extracted from Alliander's load profiles.
This master thesis could be improved by trying out more machine learning models, improving the process of normalization of load profiles and acquiring better heat pump only load profiles which are more similar to Alliander's set in terms of usage patterns among many others. Further work can be built upon the results of this thesis. Once heat pump owners have been identified based on load profiles, similar work can be done for identification based on voltage profiles. The advantage of using voltage profiles rather than load profiles is the fact that voltage profiles are not as privacy sensitive. Furthermore, providing more insight into the kind of heat pumps the users are utilizing (air-to-air or water source or geothermal) might provide further insight. Last but not least, the models developed in this master thesis could be deployed in Alliander and used to investigate heat pump ownership among entire dataset of 120k load profiles at the disposal of Alliander.
The compression-resorption heat pump (CRHP) can be distinguished from a traditional vapor-compression heat pump (VCHP) by operating with non-azeotropic mixtures and an incomplete evaporation in the desorber. The working fluid enters the compressor as a two-phase mixture. This type of compression is known as wet compression. The efficiency of the wet compression process has significant influence on the performance of the complete heat pump system. Ammonia water mixtures are often used in this type of heat pump systems. A new mixture, NH3-H2O-CO2, has been proposed in order to increase the performance of CRHPs. However this improvement can only be reached if the compressor efficiency is not negatively influenced by the addition of CO2.
A wet compressor model operating with NH3-H2O-CO2 is developed in order to predict the efficiency of the compressor. The model indicates improvements on the isentropic efficiency of the compressor with NH3-H2O-CO2 compared to ammonia water up to 3.5 %. With the compressor model heat pump applications can be investigated by taking into account the efficiency of the compressor, predicted with the model. Especially for heating applications, improvements on the heat pump system operating with NH3-H2O-CO2 are indicated. Experimental validation of the compressor model is the next important step at this point.","Wet compression; screw compressor; ammonia water; NH3-H2O-CO2; Compression-resorption heat pump; COP; Isentropic efficiency; Indicated power","en","master thesis","","","","","","","","2022-05-13","","","","Mechanical Engineering","",""
"uuid:0913c6df-9f01-42a5-add2-302ff0f2b156","http://resolver.tudelft.nl/uuid:0913c6df-9f01-42a5-add2-302ff0f2b156","Highly efficient absorption heat pump and refrigeration systems based on ionic liquids: Fundamentals & Applications","Wang, M. (TU Delft Engineering Thermodynamics)","Infante Ferreira, C.A. (promotor); Vlugt, T.J.H. (promotor); Delft University of Technology (degree granting institution)","2019","Improving efficiencies of thermal energy conversion systems is an important way to slow down global warming and mitigate climate change. Vapor absorption heat pump and refrigeration cycles are highly efficient ways of heating and cooling. These thermally activated systems also provide opportunities for the integration with a wide spectrum of low-grade and renewable heat sources, such as district heating networks, exhaust industrial heat, concentrated solar thermal energy and biomass. New fluids - ionic liquids - have been introduced into the absorption refrigeration/ heat pump field as absorbents to overcome drawbacks of traditional working fluids and to improve the energetic efficiency of systems. Some ionic liquids show high boiling points, superior thermal and chemical stabilities and strong affinities with refrigerants. Ammonia (NH3) is an environmentally friendly refrigerant with favorable thermodynamic and transport performance. Thus, studies in this thesis placed emphasis on the ammonia/ionic liquids working pairs. Studies in this thesis focus on exploring applications of ammonia/ionic liquid based vapor absorption refrigeration cycles, from a practical point of view in the refrigeration and heat pump field. By applying multi-scale evaluations covering thermodynamic and heat and mass transport aspects, it is intended to further understand the fundamentals of applying ionic liquids in heating and cooling systems. The highlights include: Assessments of equilibriummodels applied for ammonia-ionic liquid working fluids; Prediction of properties of ammoniaionic liquid fluids using molecular simulation; Collection and modeling of relevant thermophysical properties; Evaluation of the heat and mass transfer performance. Besides, concepts of using ionic liquids as absorbents with ammonia as the refrigerant in various thermodynamic cycles are analyzed and evaluated for applications in the built environment and industry...","Absorption cycle; ionic liquid; Ammonia; refrigeration; Heat pump; Plate heat exchanger","en","doctoral thesis","","978-94-6366-134-8","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:357c298c-633b-43fa-8be7-19f30fd1f412","http://resolver.tudelft.nl/uuid:357c298c-633b-43fa-8be7-19f30fd1f412","Environmental impact of the materials used in the Dutch heat transition","van der Kooij, Jim (TU Delft Technology, Policy and Management)","Sprecher, B. (mentor); Jansen, S.C. (graduation committee); Delft University of Technology (degree granting institution); Universiteit Leiden (degree granting institution)","2019","The Dutch government set two environmental goals by 2050. One of them is being climate neutral and the other one is to have a circular economy. In order to meet both goals in the best environmental conditions, extensive environmental research is required. This thesis is one of these researches and its main focus is on the climate neutral goal by 2050. In this thesis I start by creating a generic model in ArcGIS that will calculate the required materials and their environmental impacts for the implementation of high and low district heat networks and for air-water heat pumps in residential buildings. The model uses national spatial data of buildings, heat networks, and energylabels and combines them with material data that is retrieved from life cycle inventories (LCI) out of life cycle assessment (LCA) papers, material databases, several manuals, technical specifications on websites and own examination. The model is applied to the Merenwijk in Leiden. The model’s results show that for the Merenwijk the indirect environmental impact of the materials will reduce the total reduction in the heat pump scenario by approximately 10% and will be covered in the first 2 years of operation. On the material demand side, the model shows that the Netherlands will face problems with the demand for glass and glass wool. The current market for both materials should be intensified by 4 to 5 times in order to meet the expected demand. Glass wool demands will even reach 2% of the current global mineral wool market. In conclusion this thesis provides an addition to current environmental calculations by looking at the material environmental impact in the Dutch heat transition. The environmental impact of materials does have a significant impact on the overall environmental calculations.","GIS; LCA; Heat transition; Materials; Environmental impact; Heat pump; District heating; Insulation","en","master thesis","","","","","","The Master's programme Industrial Ecology is jointly organised by Leiden University and Delft University of Technology","","","","","","Industrial Ecology","",""
"uuid:44e88dad-0c83-4a19-96af-c600dba29768","http://resolver.tudelft.nl/uuid:44e88dad-0c83-4a19-96af-c600dba29768","Integrating Installations into a Zero-Energy Renovation","Berkhout, Rosanne (TU Delft Architecture and the Built Environment)","Klein, Tillmann (mentor); van den Engel, Peter (graduation committee); Delft University of Technology (degree granting institution)","2019","In order to counter climate change many approaches have been taken to make
the building sector more sustainable. But for porch houses there aren't many
solutions on the market. This research project uses one of the approaches that
is does focus on porch houses, 2ndskin. In march 2018 a demonstrator project
has been build in Vlaardingen using the 2ndskin approach. The research found a
problem with integrating the installations, they took up a lot of space and were so heavy that an extra foundation was needed. This problem is not unique to 2ndskin or the zero-on-the-meter renovations of porch houses, it's a problem in other sustainable projects as well. Therefore this research has looked into the following problem:
The installations needed to renovate a post-war porch house in accordance with the 2ndskin approach are too heavy and take up a lot of valuable space.
Current systems have been analyzed in order to solve this problem. The
comparison of these systems unveiled the main causes of the size and weight
of these systems: Empty space between the installations, placement of the
connections, required space for installation and maintenance, the kind of
installations used and the integration between them. In the end three concepts
where presented. Prioritizing different aims, the concepts show different ways
to integrate the installations according to different priorities.. For the 2ndskin
demonstrator project these concepts show that its possible to decrease the by
50% to 70% and the weight by 30% to 60%. The amount of possible decrease
depends on the priorities within the project. But, smaller installations spaces are
possible when designing from within the installations instead of around it.","heat pump; sustainable design; Size optimization; Weight Reduction; Porch houses; social housing; 2ndskin; ventilation; integration","en","master thesis","","","","","","","","","","","","","2ndskin","51.54419, 4.19393"
"uuid:18e9d987-9343-458c-a007-36b587ae3d42","http://resolver.tudelft.nl/uuid:18e9d987-9343-458c-a007-36b587ae3d42","Developing a BIPVT: Building Integrated PV-Thermal System","Garg, Shiwankar (TU Delft Electrical Engineering, Mathematics and Computer Science)","Santbergen, R. (mentor); Smets, A.H.M. (mentor); Mensink, Michiel (mentor); Delft University of Technology (degree granting institution)","2018","Photovoltaic Technologies in recent years have gained immense attention owing to reduced costs and increasing efficiencies. While decades of research in Photovoltaic Thermal (PVT) technologies, producing thermal and electrical energy simultaneously have brought these costs further down, improving a system’s overall performance. PVT collectors consist of PV modules with a thermal absorber bonded/attached underneath them. Excessive solar radiation that is not converted into electricity by the panels is released as heat, causing their temperatures to rise. Rising PV panel temperatures have an adverse effect on their efficiency, particularly for building integrated photovoltaics, that generally lack sufficient ventilation for this heat release. Thermal absorbers for PVT systems, are designed specifically for absorbing the excess heat generated by PV modules. In practise, helping the panels perform better by effectively removing the heat present behind them, with the help of a heat transfer fluid.
This project has been a collaborative effort between the TU Delft, and Exasun BV, a solar panel manufacturer located in the Netherlands. At Exasun, the project has also benefited by being a part of a larger consortium project, the PVT inSHaPe, currently underway at the Solar Energy Application Centre (SEAC), in Eindhoven. PVT inSHaPe aims to realise zero energy buildings by integrating PVT systems with heat pumps alongside effective thermal storage. As a manufacturer, Exasun BV specialises in state of the art building integrated photovoltaic systems (BIPV). BIPV systems aim to integrate photovoltaic technologies seamlessly into building facades. In doing so, they forego essential thermal ventilation required for maintaining lower panel temperatures. Thus, a novel BIPVT design was developed in-house at Exasun, for extracting the excess heat of panels, and utilising it to match the domestic hot water and space heating demand for Dutch households.
A simple thermal model for concentrating PV-Thermal collectors, currently under development at the TU Delft was validated alongside widely used steady-state and quasi-dynamic thermal models. Individually calculated thermal efficiencies from the models were juxtaposed, with the simple thermal model recording an error of 1.65% against the steady-state model, and an error of 9.21 % against the quasi-dynamic model. Once validated, the model was used further for system characterisation and performance evaluations of the design.
Various technology concepts have been tested extensively. However, further feasibility, reliability and optimisation studies need to be performed, in order to test the novel, cost-effective, and relatively maintenance free design in mind. The performance of PVT systems rely on high irradiance levels from the sun, and module temperatures. As space heating demands are higher during winter months, even after heat pump integration, the system is not effective enough to match the entirety of the load demand, and must be coupled with an auxiliary (electrical) heater, that can be powered by the PV system. Presumptive performance analysis carried out for a simulated household, revealed an average thermal efficiency of 10 % for the design, while recording a combined efficiency of 36 %. The stand-alone system was able to match over 55 % of the domestic hot water demand. When combined with a heat pump, the system is able to meet roughly 80 % of the hot water demand, while it is able to match almost 40 % of the complete thermal demand for a household.","BIPVT; PVT; Heat pump; PVT heat pump integration; Model validation; A simple thermal model","en","master thesis","","","","","","","","2019-01-01","","","","Electrical Engineering | Sustainable Energy Technology","",""
"uuid:ac8b24f5-662f-4348-82f1-609ff30567bb","http://resolver.tudelft.nl/uuid:ac8b24f5-662f-4348-82f1-609ff30567bb","Fault Detection and Diagnosis of Industrial Heat Pumps of GEA B.V.","Hofstad, Magnus (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Engineering Thermodynamics)","Infante Ferreira, C.A. (mentor); Gerritsen, J (mentor); Ferrari, Riccardo M.G. (graduation committee); Vlugt, T.J.H. (graduation committee); Delft University of Technology (degree granting institution)","2018","Heat pumps represent an effective technology to convert electrical energy to thermal energy through the expansion and compression of a refrigerant. Heat pumps are becoming increasingly more efficient which decreases energy consumption. However as heat pumps are getting increasingly more efficient, complexity is also increasing which leads to failures.
GEA is one of Europe’s largest providers of industrial heat pumps, delivering a variety of different industrial heat pumps for food production, breweries, waste heat recovery, and thermal power plants. As industrial heat pump systems are becoming increasingly complex, so is the task of detecting faults in the systems. Whenever a heat pump breaks down it is challenging to see what the reason for the failure is without visual inspection. A typical service engineer will have data from over 20 sensors, each with over two and a half million measurement intervals, to inspect and look for the cause of failure. Visual inspection of the heat pump systems can only be done by experienced engineers who knows
exactly what to look for and where to look for it.
As heat pumps have been developing so has the sensor technology and computational resources available in modern computers. Over the last decades the price of sensors has decreased rapidly while the capability and reliability of sensors has improved. The computational power of modern computers has increased significantly while the price for these resources has decreased.
Several other industries have, with the development in sensor technology and computational power, investigated the possibilities of implementing Fault Detection & Diagnosis (FDD) programs to automatically
analyze sensor data in order to detect failures and diagnose the failure cause. FDD programs were previously limited to critical processes, for example power plants, aerospace, or national defence. They
were expensive programs due to the sensor requirements, the computational resource requirements and the development costs. However, as the price of sensors and computational resources has been
decreasing, FDD is becoming increasingly more popular for less critical equipment. For the past two decades FDD programs have been developed for different Heating, Ventilation, Air-Conditioning and Refrigeration (HVAC&R) equipment with a special focus to refrigeration.
This project aims to develop a FDD program for GEAs industrial heat pump systems. Following a literature study it was concluded that thus far, FDD programs have not been utilized for heat pump systems of this complexity. It was seen that most FDD programs use a quantitative, qualitative or process history based approach to detect faults. Quantitative FDD programs aim to design a digital twin of the system at hand based on physical relations, and compare measured values to defined values for
faulty or fault-free operation. Qualitative FDD programs aim to mimick the behaviour of system experts and base decisions on previously seen failures and cases. Process history based FDD programs aim
to learn how systems should ideally behave through an abundance of operational data, and compare systems to sampled data.
The FDD program for GEA uses a qualitative approaches for all faults where expert knowledge is available. For faults not seen before, a process history based approach classifies operation as faulty or
fault-free. The complexity of the faults and the system do not allow for a quantitative FDD program. A predefined list of in total 23 faults was agreed upon, the FDD program further aims to detect all 23 failures and diagnose the failure cause.
The project is meant as a proof of concept for GEA. By proving that an off-line FDD program is possible, GEA can ultimately implement the algorithms used in this off-line FDD program in to the control system of the heat pumps to increase the reliability of their heat pumps and detect faults as they are occurring.","Heat pumps; Fault Detection; Failure Prediction; GEA; Industrial applications","en","master thesis","","","","","","","","2023-11-03","","","","Mechanical Engineering","",""
"uuid:71bbbc7f-8c6b-42b6-a423-87bc78b28b45","http://resolver.tudelft.nl/uuid:71bbbc7f-8c6b-42b6-a423-87bc78b28b45","Investing in a changing world: The combination of ABM and Bayesian network tested in the Dutch heat pump market","Keemink, Wessel (TU Delft Technology, Policy and Management)","van Gelder, P.H.A.J.M. (graduation committee); Nikolic, I. (mentor); Khakzad, N. (graduation committee); Delft University of Technology (degree granting institution)","2018","This thesis focuses on the combination of agent based modelling and Bayesian network. These techniques are used to see if this is a viable way of modelling green markets, like the heat pump market. These markets can change quickly. The combination of the techniques gives the investors in the model the ability to learn from new information during the model and change their strategy or decision upon this. The outcomes show that this is a promising combination and future research should be done to further explore the possibilities.","Agent-Based Modelling; Bayesian Network; Heat pumps; Green investments","en","master thesis","","","","","","","","","","","","Complex Systems Engineering and Management (CoSEM)","",""
"uuid:3e4a4a1b-b32a-4084-8645-afc47767beaf","http://resolver.tudelft.nl/uuid:3e4a4a1b-b32a-4084-8645-afc47767beaf","Distinctions in heat pump pools for participation in the Dutch balancing market","van den Meiracker, Tom (TU Delft Technology, Policy and Management)","Weijnen, M.P.C. (graduation committee); Hakvoort, R.A. (mentor); Warnier, Martijn (graduation committee); Bogerd, J.C. (graduation committee); Delft University of Technology (degree granting institution)","2018","Electricity is a basic need in today`s society, being present in almost every aspect of life. The extensive infrastructure that transports electricity to the consumers, is expected to always work. At the same time there is a growing realism that the energy sector needs to modernise and ‘greenify’, in order to become more climate friendly. This is realised in the Netherlands by increasing the electricity produced by rooftop solar panels and wind parks.
Electricity produced by solar and wind depends on weather circumstances. Their production pattern is much more variable and uncertain than conventional fossil power plants. In order to maintain the balance on the electricity grid, an increased amount of balancing power is needed. For the Netherlands this is estimated to reach 15.2 TWh in the year 2050.
New sources of balancing power are also established by becoming more climate friendly. In the Netherlands the electrification of demand, results in gas fired boilers being replaced by heat pumps. Not just the established ground water based variant, but also the air based heat pump.
The heat pumps capability of providing balancing power is based on two aspects. First are the well-insulated houses in which they are installed. This reduces the cooling rate. Secondly is that residents generally do not experience any discomfort when the room temperature slightly deviates from their comfort temperature. And when they are absent, the room temperature may take any value.
Among the houses and residents where a heat pump is installed, differences can be found. Not everyone lives in a detached house, and not everyone is absent during the day. The effect of these differences on the demand response from a pool of heat pumps, is not known. This leads to the main research question:
“To what extent can a distinction in different residents and houses, increase the accuracy of demand response calculations for a Dutch heat pump pool?”
In order to answer the research question, a model based approach is chosen. The ISO 13790 modelling approach is selected, as it includes the following requirements:
1.Includes the comfort temperature of the resident
2.Includes the 4 MW participation requirement of the secondary reserve market
3.Allows the comfort temperature to change on an hourly basis
4.Allows for a distinction between different houses and residents
5.Includes the room temperature
6.Includes the air based heat pump`s dependency on the outside temperature
As a result of the 4 MW participation requirement, heat pumps need to be combined into a pool. An aggregator is tasked with controlling this pool, and offering the demand response to the market. It is the aggregator that must predict the demand response available from each heat pump. Distinguishing between the different houses and residents, should increase the accuracy of predictions.
The distinction between the different houses and residents programmed into the model, depends strongly on the information available about the region. The region chosen in this research is the Netherlands. For this region four different categories of houses have been identified, each with a different cooling rate.
•Detached house
•Semi-detached house
•Terraced house middle
•Terraced house corner
In case of the residents three different types have been identified. Each having a different comfort temperature and a different daily routine.
•The single
•The couple
•The family
Each of the three types of residents could live in any of the four categories of houses. All of the possible combinations have been included in the experiments. In the experiments the demand response available from the two types of heat pump has been calculated, in both the up- and downward direction. The demand response is here defined as the intentional deviation in the electric load, compared to the normal use of the heat pump.
The results of the experiments show that both types of heat pump are capable of keeping the house near to the comfort temperature. Between the two types of heat pump a significant difference was found. The air based variant is capable of providing more demand response, especially during the winter.
A significant difference was also found between the three different types of residents, and almost all of the four different categories of houses. With the exception of the semi-detached house and the terraced house middle, where no significant difference was found in the upward direction.
The conclusion is that by making a distinction between residents, houses and heat pumps the accuracy of calculations will increase.
The differences in the demand response available from each combination, effect the number of heat pumps needed for the 4 MW participation requirement. Depending on the time of day, the size of the pool would range between less than 10.000, and more than 180.000. It can be stated that it is not about finding the size of the pool that allows an aggregator to always participate. But it is about determining when an aggregator is capable of participating, based upon the pool he controls.
With the growing balancing power needed by 2050, heat pumps will be capable of providing part of the needed capacity. However, the balancing power offered fluctuates strongly depending on the time of day and season. Next to that, it will require large numbers of heat pumps in order to participate.
To heat a building, a certain heat input is necessary to keep the building on the same temperature. This heat demand can be determined by standardized yearly values used in the sector. If these are distributed monthly over a year, a mean heat demand per second can be determined. This heat demand is provided by harvesting heat out of the water on the roof by using a heat pump. Therefore the temperature of the water changes. To state that the water may not turn into ice, a maximum daily heat drainage can be calculated. The total amount of thermal energy which can be harvested is determined by the water’s temperature and volume. The temperature of the water is influenced by the temperature of the air in contact with the water, incoming radiation and outgoing heat from the building underneath. The volume rises through precipitation on the roof and lowers by evaporation and the discharge from water of the roof. The influence of the air on the water temperature is modelled with the Cooling Law of Newton.
By modelling the described system, an equilibrium temperature difference between water and air can be found with a given heat demand. When cooling is needed, this difference will also occur because the heat pump transfers heat into the water and is cooled by the air. This method for heating a building can be used from March to November in the Netherlands. By using another isolation layer which can retain more radiation instead of the green layer, the applicability can be increased. Cooling with a heat pump can be applied if the cooling demand is low. A high water temperature is adversely for the efficiency of the heat pump and the vegetation. Because a Polder Roof isolates a building better than a conventional roof, the building has a lower cooling demand, so the temperature of the water will rise less. The use of a heat pump is more energy-efficient than a conventional installation, on the condition that the COP is higher than 1.33.","Heat pumps; Polder roofs; Green Blue roofs; Watermanagement","nl","bachelor thesis","","","","","","","","","","","","Civil Engineering","",""
"uuid:af334c80-eefd-4f78-a0b5-77091c13c6a7","http://resolver.tudelft.nl/uuid:af334c80-eefd-4f78-a0b5-77091c13c6a7","In silico screening of metal-organic frameworks for adsorption-driven heat pumps and chillers","Erdös, M.; de Lange, M.F. (TU Delft Engineering Thermodynamics); Kapteijn, F. (TU Delft ChemE/Catalysis Engineering); Moultos, O. (TU Delft Engineering Thermodynamics); Vlugt, T.J.H. (TU Delft Engineering Thermodynamics)","","2018","A computational screening of 2930 experimentally synthesized metal-organic frameworks (MOFs) is carried out to find the best-performing structures for adsorption-driven cooling (AC) applications with methanol and ethanol as working fluids. The screening methodology consists of four subsequent screening steps for each adsorbate. At the end of each step, the most promising MOFs for AC application are selected for further investigation. In the first step, the structures are selected on the basis of physical properties (pore limiting diameter). In each following step, points of the adsorption isotherms of the selected structures are calculated from Monte Carlo simulations in the grand-canonical ensemble. The most promising MOFs are selected on the basis of the working capacity of the structures and the location of the adsorption step (if present), which can be related to the applicable operational conditions in AC. Because of the possibility of reversible pore condensation (first-order phase transition), the mid-density scheme is used to efficiently and accurately determine the location of the adsorption step. At the end of the screening procedure, six MOFs with high deliverable working capacities (∼0.6 mL working fluid in 1 mL structure) and diverse adsorption step locations are selected for both adsorbates from the original 2930 structures. Because the highest experimentally measured deliverable working capacity to date for MOFs with methanol is ca. 0.45 mL mL-1, the selected six structures show the potential to improve the efficiency of ACs.","adsorption; chillers; heat pumps; metal-organic frameworks; Monte Carlo","en","journal article","","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:d88d21d4-8b27-4b8d-93af-9f18f8d49207","http://resolver.tudelft.nl/uuid:d88d21d4-8b27-4b8d-93af-9f18f8d49207","The Influence of Financial Incentives on the Adoption of Heat Pumps in the Netherlands: A diffusion study using Agent Based Modelling","Swart, Ron (TU Delft Technology, Policy and Management)","Herder, Paulien (mentor); Fens, Theo (mentor); Mouter, Niek (mentor); Chappin, Emile (mentor); Delft University of Technology (degree granting institution)","2017","","Heat pumps; Innovation diffusion; Adoption; Netherlands","en","master thesis","","","","","","","","","","","","Complex Systems Engineering and Management (CoSEM)","",""
"uuid:4c67ea0b-837c-4aed-994d-7f89c42f40e9","http://resolver.tudelft.nl/uuid:4c67ea0b-837c-4aed-994d-7f89c42f40e9","Simulating the flexibility potential of demand response with heat pumps in the Netherlands","van Etten, Max (TU Delft Technology, Policy and Management; TU Delft Multi Actor Systems)","Warnier, Martijn (mentor); Delft University of Technology (degree granting institution)","2017","The growth of electricity generated by renewables increases the intermittency of the Dutch electricity production. To deal with this, the Dutch power system requires a higher amount of flexibility in the future. Demand response with heat pumps is one of the options with a high potential to provide flexibility, because it offers the potential to store energy close to demand. In this thesis, the potential for electricity cost reduction with demand response with heat pumps for space heating by using the thermal inertia of buildings in the Netherlands is investigated. The effect of different heat load profiles, seasonality, and different comfort requirements on the economic potential demand response with heat pumps is analysed. An existing Matlab model is revised and expanded to perform simulations with different cluster types, seasons and predefined comfort limits. The model simulates the DR algorithm, R.E.X., and shifts the load of clusters based upon their thermal demand and the EPEX market prices within the predefined technical and consumer flexibility constraints, to analyse the potential of operational cost reductions of DR with heat pumps. Therefore, the key input parameters of the model are: (1) the thermal demand, (2) electricity market prices, and (3) the flexibility constraints. The key output parameters are: (1) the operational savings in euro, (2) the operational savings in percentage, and (3) the amount of shifted load. The model design, behaviour and results are validated with an expert validation.
It is concluded, that DR with heat pumps can facilitate flexible balancing of supply and demand by aggregators in the Netherlands. The potential of DR with heat pumps for different stakeholders can increase depending upon the penetration of RES-E, heat pumps and EVs. Current obstacles for the development of DR of heat pumps are the high share of fixed energy taxes and the reduced efficiency and lifetime of the heat pump when DR is used. Designing flexible tariffs and a focus on flexibility in the re-design of heat pumps can take these obstacles away.","Flexibility; Demand Response; Heat pumps; Heat load profiles; Seasonality; comfort requirements","en","master thesis","","","","","","","","","","","","Complex Systems Engineering and Management (CoSEM)","",""
"uuid:b1a48e1c-686b-4c1b-a86d-46f5a1a5a72b","http://resolver.tudelft.nl/uuid:b1a48e1c-686b-4c1b-a86d-46f5a1a5a72b","Absorption of Ammonia-Water and CO2-NH3-H2O Mixture in Mini-Channel Heat Exchangers","Shi, L.","Infante Ferreira, C.A. (mentor)","2017","The energy consumption in the industry field is considerable. Saving energy has great potential in many industrial processes. For example, heat recovery from the spent cooling water can be achieved by applying heat pump technology, and the recovered heat can be used for district heating. Previous study indicates that the compression-resorption cycle has higher efficiency than traditional vapor-compression heat pumps due to the fact that it can take advantage of the temperature glide of the multi-component working fluid. The absorption process within the resorber and its performance should be further investigated. Ammonia-water mixture is commonly used as the working fluid in the compression-resorption heat pump. Recently the CO2-NH3-H2O mixture has been identified as a promising working fluid theoretically, relevant experiment should be conducted to verify it. For the theoretical background, previous studies about kinetics of CO2 absorption in ammonia-water have been reviewed. Currently most of the theoretical and experimental studies are performed for post combustion capture usage. The working conditions deviate much from that for the compression-resorption heat pump cycle; therefore existent kinetic models are not suitable for predicting the absorption rate of the CO2 in ammonia-water within a compression-resorption heat pump cycle. Previous studies from TU Delft indicate that a more accurate model should be developed to predict the absorption process of the ammonia-water mixture in a multi-tube mini-channel heat exchanger. In this study a steady-state theoretical model has been developed to predict the absorption process of ammonia-water mixture in a multi-tube mini-channel heat exchanger by assuming Nusselt falling film theory and annular flow pattern. The model is extended to cover all three different phases (superheated vapor, 2-phase, and sub-cooled liquid) of the ammonia-water mixture. Experiments with two different working fluids (ammonia-water mixture and CO2-NH3-H2O mixture) on the tube side and cooling water on the shell side have been performed respectively. Results indicate that adding a small amount of CO2 (2.1 wt%) directly will lead to slightly better heat exchange on the water side when operated in optimum condition. But the operating status becomes much less stable than the experiment with ammonia-water as a working fluid. The pump becomes difficult to operate with constant mass flow. While when the flow directions on both sides are changed, more stable operating conditions can be achieved. This indicates the configuration of the heat exchanger and the flow direction influence the operating stability. Also it is possible to have CO2 desorbed at the pump even in low temperature. Therefore to put into practical use, more tests should be done to comprehensively investigate the feasibility of applying CO2-NH3-H2O mixture as working fluid in a compression-resorption heat pump. The theoretical model has been validated by the experimental data. For the 2-phase flow condition on the tube side, the simulation results indicate that the assumption of annular flow pattern is reasonable for most of the heat exchange area. But when the vapor quality is low, the film thickness prediction based on the Nusselt falling film theory is not reasonable any longer, this indicates a transition of a flow pattern. A new flow pattern occurs in order to enhance the transport phenomena. The validation results show that the extended model can accurately predict the heat load and the temperature profile along the absorption process. However the pressure drop cannot be reasonably predicted. This can be caused by inaccurate friction factor estimation or ignorance of other effects which can cause extra pressure drop. The heat transfer performance at the superheated region is studied in detail. Results show an obscure relation between the weakened heat transfer phenomenon and the hydrodynamic instabilities on the tube side. Experimental data are also applied to validate the thermodynamic equilibrium models for the CO2-NH3-H2O mixture. The model developed in this project can be used to predict the heat transfer performance for certain type of heat exchangers conducting ammonia-water absorption process, or be modified to apply for other conditions. The experimental data are useful for ammonia-water and CO2-NH3-H2O mixture absorption related studies. As a follow-up for this research it is of interest to further investigate and identify the flow pattern transition when the vapor quality is low, and develop a more comprehensive model to predict the absorption process. Visual observations will help to understand the flow pattern transitions. A complete compression-resorption heat pump setup will contribute to more useful experimental result to estimate the performance using CO2-NH3-H2O mixture as a working fluid.","compression-resorption heat pumps; ammonia-water mixture; absorption; mini-channel heat exchangers; waste heat recovery; CO2-NH3-H2O mixture; steady state model","en","master thesis","","","","","","","","","Mechanical, Maritime and Materials Engineering","Process and Energy","","","",""
"uuid:05fd9db8-0830-43fe-b55f-79549b7f09f8","http://resolver.tudelft.nl/uuid:05fd9db8-0830-43fe-b55f-79549b7f09f8","Enhanced performance of wet compression-resorption heat pumps by using NH3-CO2-H2O as working fluid","Gudjonsdottir, V. (TU Delft Engineering Thermodynamics); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics); Rexwinkel, G. (Frames); Kiss, AA (Akzo Nobel)","","2017","Upgrading waste heat by compression resorption heat pumps (CRHP) has the potential to make a strong impact in industry. The efficiency of CRHP can be further improved by using alternative working fluids. In this work, the addition of carbon dioxide to aqueous ammonia solutions for application in CRHP is investigated. The previously published thermodynamic models for the ternary mixture are evaluated by comparing their results with experimental thermodynamic data, and checking their advantages and disadvantages. Then the models are used to investigate the impact of adding CO2 to NH3-H2O in wet compression resorption heat pump applications. For an application where a waste stream is heated from 60 to 105 °C, a COP increase of up to 5% can be attained by adding CO2 to the ammonia-water mixture, without any risk of salt formation. Additional advantages of adding CO2 to the ammonia-water mixture in that case are decreased pressure ratio, as well as an increase in the lower pressure level. When practical pressure restrictions are considered the benefits of the added CO2 become even larger or around 25% increase in the COP. Nonetheless, when the waste stream was considered to be additionally cooled down, no significant benefits were observed.","Compression resorption; Heat pumps; Heat recovery; NH-CO-HO mixture; Thermodynamic model","en","journal article","","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:f3dd8980-d142-4a49-8c97-e99ae8e46697","http://resolver.tudelft.nl/uuid:f3dd8980-d142-4a49-8c97-e99ae8e46697","Absorption of CO2-NH3-H2O mixture in mini-channel heat exchangers","Shi, Liang; Gudjonsdottir, V. (TU Delft Engineering Thermodynamics); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics); Rexwinkel, Glenn (Frames); Kiss, Anton A. (Akzo Nobel)","","2017","Compression resorption heat pumps (CRHP) are a promising option to upgrade waste heat from industry. Alternative working fluids can further improve the efficiency of CRHP. The ternary mixture NH3-CO2-H2O has been identified as a promising working fluid for CRHP and has the potential to further enhance the coefficient of performance (COP) of the cycle compared to the traditionally used ammonia water mixture. So far the studies on the NH3-CO2-H2O mixture have focused mainly on carbon capture applications. But the desired operating conditions are different than for CRHP applications, e.g. the NH3 concentration. Additionally the absorption process with the mixture in tubular absorbers has not yet been reported. The focus of this study is therefore to investigate experimentally the absorption process of a CRHP with this ternary mixture. To reach this goal a model is developed for ammonia-water that takes into account the kinetics and mass transfer during the absorption process. To validate the model, experiments were performed for an absorption process in a mini channel heat exchanger with NH3 concentration of 35 wt%. The results show a good match between the model and the experiments. Additionally CO2 has been added to the solution and the experimental performance was compared with the experimental performance of the NH3-H2O mixture. A concentration of 2 wt% CO2 resulted in a performance increase of up to 5% however the working fluid flow became limited by pumping instabilities.","heat pumps; NH3-CO2-H2O mixture; NH3-H2O mixture; waste heat recovery; absorption; mini-channel heat exchangers","en","conference paper","Stichting HPC 2017","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:fe221324-9382-4c58-90ec-f70b7806094b","http://resolver.tudelft.nl/uuid:fe221324-9382-4c58-90ec-f70b7806094b","Performance analysis of double-effect absorption heat pump cycle using NH3/ILs pairs","Wang, M. (TU Delft Engineering Thermodynamics); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","","2017","Ionic liquids (ILs), as novel absorbents, draw considerable attention for their potential roles in replacing H2O or LiBr aqueous solutions in conventional NH3/H2O or H2O/LiBr absorption chiller or heat pump cycles. In this paper, NH3/IL working pairs are proposed for implementation in parallel double effect heat pump systems. To investigate their performance, a property-prediction method, based on experimental heat capacities and the nonrandom two-liquid (NRTL) activity coefficient model for the vapor pressure, was used to estimate the thermodynamic properties for the proposed NH3/IL mixtures. Then, parallel configuration double-effect absorption heat pump cycles driven by a high-temperature heat source were analyzed by means of evaluation of the thermodynamic operating limits and performance simulations with the aforementioned properties. The ILs investigated include [Mmim][DMP], [Emim][BF4], [Hmim][BF4], [Omim][BF4], [Bmim][BF4], [Bmim][PF6], [Emim][Tf2N], [Emim][EtSO4] and [Emim][SCN]. The performance, such as the coefficient of performance, COP, and circulation ratio f, along with the environmental temperature used as heat source were compared for these ILs based pairs and the conventional ones. This work on double-effect heat pumps with NH3/ILs pairs shows that there is an optimum distribution ratio between the parallel flows and that some of the investigated mixtures have the potential to show a better performance than that of the traditional NH3/H2O pair in cooling and heating applications.
3/ionic liquid mixtures for absorption heat pump cycles","Kabra, Abhishek; Becker, T. (TU Delft Engineering Thermodynamics); Wang, M. (TU Delft Engineering Thermodynamics); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics); Vlugt, T.J.H. (TU Delft Engineering Thermodynamics)","","2017","Force Field based Monte Carlo (MC) simulations are conducted to predict the performance of an absorption heat pump cycle involving NH3/ionic liquid (IL) (refrigerant/absorbent) as working pair. To investigate the thermodynamic performance of the cycle, various properties such as the enthalpy of absorption, heat capacity, and solubility of refrigerant in the absorbent are required. As an alternative to experiments, MC simulations are used to predict the required properties. The simulations are performed at temperatures ranging from 303 K to 373 K and pressures ranging from 4 to 16 bar. The thermodynamic performance parameters such as the coefficient of performance, COP, and the circulation ratio, f, of NH3 paired with [emim][Tf2N] are investigated using MC simulations and compared to results obtained from correlated experimental data, showing a reasonable agreement. MC simulations could be used as an inexpensive alternative for preliminary design considerations involving potential working pairs for absorption heat pump cycles in the absence of available experimental data.","Working pair; Absorption cycle; Monte Carlo simulations; Heat pump; Ionic liquids; NH3","en","conference paper","Stichting HPC 2017","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:fb000216-03cf-486a-a268-189674b0d421","http://resolver.tudelft.nl/uuid:fb000216-03cf-486a-a268-189674b0d421","Control strategies of CO2 refrigeration / heat pump system for supermarkets","Shi, Liang; Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics); Gerritsen, Jan (Frijado Retail); Kalkman, Hendrine (Frijado Retail)","","2017","CO2 is a promising refrigerant compared to traditional HFCs due to its insignificant global warming potential and nonthreatening to the ozone layer. It has been used as refrigerant in industrial and commercial refrigeration in recent years. With high compactness and the ability to recover heat, CO2 booster systems have been widely installed in newly constructed supermarkets in the Netherlands. One remarkable advantage of this system is that great amount of heat can be recovered from the gas cooler for heating use due to high temperature driving force from CO2. Sometimes the COP is sacrificed to fully satisfy the heating demand. Within the present work, a quasi-steady-state computer model has been developed to study the performance of the system based on a typical Dutch supermarket. The model has been validated using experimental data. By altering condensing pressure and gas cooler capacity using different methods, various control strategies to satisfy both cooling and heating demand have been proposed and compared. The results from the simulation illustrate that some control strategies have lower energy consumption and easier operation compared to the others. The study also shows that CO2 booster refrigeration system has a good potential for heat recovery. It has the potential to save 13% primary energy compared to conventional heating method in supermarkets.","CO2 refrigeration / heat pump system; supermarket; heat recovery; control strategies","en","conference paper","Stichting HPC 2017","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:00aab992-3f19-435d-b02d-2dd3d9e47f68","http://resolver.tudelft.nl/uuid:00aab992-3f19-435d-b02d-2dd3d9e47f68","Techno-economic feasibility study of a system for the transfer of refrigeration capacity from LNG regasification plants to industrial assets","Pineda Quijano, Diego; Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics); Duivenvoorden, Wil (Royal HaskoningDHV); Mieog, Juriaan (Royal HaskoningDHV); van der Noortgaete, Tom (Royal HaskoningDHV); van Velpen, Bart (Royal HaskoningDHV)","","2017","The recovery of cold energy during the regasification of Liquefied Natural Gas (LNG) has gained attention in recent years due to the fast growth of the LNG trade market and the increasing importance that governments are giving to energy efficiency and sustainability. Near 200 kWh/ton of LNG are potentially recoverable during the regasification process, but this energy is usually discarded when seawater or ambient air are used as heat source. Researchers have focused on the development of technologies for the use of this cold energy in the fields of air separation and cryogenic power generation. However, in some regasification plants the demand of natural gas is so low or so fluctuating that this kind of applications are economically unfeasible. This research focused on determining the techno-economic feasibility of a heat pump and a cold distribution system for the transfer of a fraction of the refrigeration capacity of LNG to industrial assets with low-temperature refrigeration demands located in the surroundings of the regasification plant. CO2 was selected as the heat transfer fluid that recirculates in a close loop between the cold users and the LNG site. A techno-economic model was implemented in Matlab taking the distance between the users and the LNG plant, and the refrigeration demand as the evaluation parameters. It was found that for a refrigeration demand of 20 MW the distance between the plants should be less than 1.2 km in order to make a project economically feasible.","waste heat recovery; Liquefied Natural Gas; R744 - Carbon Dioxide; industrial heat pumps","en","conference paper","Stichting HPC 2017","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:0f33b589-7ceb-4df5-aa82-1a9bca930fea","http://resolver.tudelft.nl/uuid:0f33b589-7ceb-4df5-aa82-1a9bca930fea","Heat recovery in milk powder drying by using a liquid sorption process","Pineda Quijano, Diego; van der Pal, Michel (ECN, Petten); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics); Boer, de, Robert (ECN, Petten); Vollenbroek, Jasper (Royal Friesland Campina)","","2017","The last step in the production of milk powder is drying, an energy intensive process that demands 30% to 40% of the total energy input of a typical plant. It takes place in Spray Dryers (SD), where concentrated milk is sprayed and placed in direct contact with hot and dry air that cools down and gains humidity as water is evaporated from milk. The warm and humid air leaving the SD contains a small portion of potentially recoverable sensible heat and a large portion of latent heat that is impractical to recover by direct condensation due to the low dew point of this stream and due to the presence of milk powder particles that become sticky at high relative humidity values. In this research, the thermodynamic feasibility of a liquid sorption system for the recovery of heat from the exhaust of SD’s was investigated. The system proposed has two main advantages: the dehumidification of air in the absorber for reuse in the SD, and the production of medium pressure steam in the regenerator for integration to the steam network of the plant. A mathematical model was implemented in Matlab, and two system configurations were evaluated. The calculations showed that a SD equipped with this system can achieve energy savings between 58% and 99% when using aqueous solutions of phosphoric acid as liquid desiccant depending on the system configuration. The challenge with this liquid desiccant remains on the construction materials.","milk powder spray drying; liquid sorption; heat recovery; energy efficiency; liquid sorption heat pump; air dehumidification; liquid desiccants","en","conference paper","Stichting HPC 2017","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:5fa33d4a-8c02-4293-bc3a-eec0ac435488","http://resolver.tudelft.nl/uuid:5fa33d4a-8c02-4293-bc3a-eec0ac435488","Absorption heat pump cycles with NH3 – ionic liquid working pairs","Wang, M. (TU Delft Engineering Thermodynamics); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","","2017","Ionic liquids (ILs), as novel absorbents, draw considerable attention for their potential roles in replacing water or LiBr aqueous solutions in conventional NH3/H2O or H2O/LiBr absorption refrigeration or heat pump cycles. In this paper, performances of 9 currently investigated NH3/ILs pairs are calculated and compared in terms of their applications in the single-effect absorption heat pumps (AHPs) for the floor heating of buildings. Among them, 4 pairs were reported for the first time in absorption cycles (including one which cannot operate for this specific heat pump application). The highest coefficient of performance (COP) was found for the working pair using [mmim][DMP] (1.79), and pairs with [emim][Tf2N] (1.74), [emim][SCN] (1.73) and [bmim][BF4] (1.70) also had better performances than that of the NH3/H2O pair (1.61). Furthermore, an optimization was conducted to investigate the performance of an ideal NH3/IL pair. The COP of the optimized mixture could reach 1.84. Discussions on the contributions of the generator heat and optimization results revealed some factors that could affect the performance. It could be concluded that the ideal IL candidates should show high absorption capabilities, large solubility difference between inlet and outlet of the generator, low molecular weights and low heat capacities. In addition, an economic analysis of the AHP using NH3/[emim][SCN] working pair with plate heat exchangers was carried out based on heat transfer calculations. The results indicated that the NH3/IL AHP is economically feasible. The efforts of heat transfer optimization in the solution heat exchanger and a low expense of ILs can help the IL-based AHP systems to become more promising.","Absorption cycle; Economic analysis; Heat pump; ILs; NH; Optimization","en","journal article","","","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:fd2cf18e-cb1d-4c9e-a22f-1971cd2e7540","http://resolver.tudelft.nl/uuid:fd2cf18e-cb1d-4c9e-a22f-1971cd2e7540","Innovative Hybrid CHP systems for high temperature heating plant in existing buildings","de Santoli, Livio (Sapienza University Roma); Lo Basso, Gianluigi (Sapienza University Roma); Nastasi, B. (TU Delft Building Physics)","d’Ambrosio Alfano, Francesca R. (editor); Mazzarella and Piercarlo, Livio (editor)","2017","This paper deals with the potential role of new hybrid CHP systems application providing both electricity and heat which are compatible with the building architectural and landscape limitations. In detail, three different plant layout options for high temperature heat production along with the electricity generation were investigated and compared each other. To do so, conventional natural gas CHPs and back up boiler, two-stage Electric Heat Pumps (EHPs) and trans-critical CO2 electric heat pump (CO2-HP) have been considered as reference technologies to build hybrid systems. In addition, hybrid solar collectors (PV/T) thermal output, along with the recovered low-grade heat from CHP exhaust gas, flowing to the stack, have been used as the CO2-HP low temperature driving source.","Building refurbishment; Hybrid Heating Systems; CHP; CO2 Heat pump; PV/T; Energy Efficiency","en","conference paper","Elsevier","","","","","","","","","","Building Physics","","",""
"uuid:c8d2adbb-625d-459c-a299-4eb3203538e9","http://resolver.tudelft.nl/uuid:c8d2adbb-625d-459c-a299-4eb3203538e9","Entropy production minimisation of a compression-resorption heat pump","Aarts, S.P.","Infante Ferreira, C.A. (mentor)","2016","Waste heat recovery is essential to reduce energy consumption in industry. A heat pump can be used to upgrade waste heat to a temperature level that is suitable for process heat. This study concerns a compression-resorption heat pump. The goal is to optimise the heat pump energetically, while keeping the investment attractive. Entropy production is a measure for energy dissipation and therefore this will be used to quantify the exergetic losses of the cycle. To minimise entropy production is equivalent to optimising the energetic performance. A literature study is performed and two models are developed and applied to an example case from industry. For the example case the calculations showed that the COP can be increased by 26 % with respect to the currently installed pentane vapour-compression heat pump. The theory of non-equilibrium thermodynamics is applied to find the local entropy production distribution in the resorber. The calculations showed that especially in the beginning of the process the entropy production rate is high. Together the models are used to evaluate the economic performance of the system. To reduce the payback period new configurations of the heat exchanging process in the resorber are investigated using the criterion of equipartition of entropy production. These investigations show that distributing the inlet mass flow over the length of the heat exchanger does not decrease the required heat transfer area. Decreasing the cross-sectional area for the flow however, does cause a reduction of the heat transfer area.","heat exchanger; Heat pump; energy efficiency; ammonia-water; non-equilibrium thermodynamics; entropy production; waste heat","en","master thesis","","","","","","","","","Mechanical, Maritime and Materials Engineering","Process and Energy","","","",""
"uuid:07499c0a-c23d-4af7-a4e3-b41ad8e69954","http://resolver.tudelft.nl/uuid:07499c0a-c23d-4af7-a4e3-b41ad8e69954","Heat Recovery in the Drying Process of Milk Powder by Using a Liquid Sorption System","Pineda Quijano, D.F.","Infante Ferreira, C.A. (mentor)","2016","The last step in the production of milk powder is drying, a very energy intensive process that demands 30% to 40% of the total energy input of a typical plant. It takes place in Spray Dryers (SD), where concentrated milk is sprayed and placed in direct contact with hot and dry air that cools down and gains humidity as water is evaporated from milk. The warm and humid air leaving the SD contains a small portion of potentially recoverable sensible heat and a large portion of latent heat that is impractical to recover by direct condensation due to the low dew point of this stream and due to the presence of milk powder particles that become sticky at high relative-humidity values. In this research, the feasibility of a liquid sorption system for the recovery of the aforementioned latent heat was investigated. The system proposed has two main advantages: the dehumidification of air in the absorber for reuse in the SD, and the production of high pressure steam in the regenerator for integration to the steam network of the plant. A mathematical model of the system was implemented in Matlab, and several system configurations were evaluated. The calculations showed that a SD equipped with this system can achieve energy savings above 55% when using aqueous solutions of phosphoric acid as liquid desiccant. The challenge with this liquid desiccant remains on the construction materials","liquid sorption; heat pump; drying; heat recovery; energy efficiency; phosphoric acid; sodium hydroxide","en","master thesis","","","","","","","","2021-08-31","Mechanical, Maritime and Materials Engineering","Process and Energy","","","",""
"uuid:5d7963b4-b3fa-40ed-b2f4-7fb1518b7ab8","http://resolver.tudelft.nl/uuid:5d7963b4-b3fa-40ed-b2f4-7fb1518b7ab8","Thermodynamic Model of a Screw Compressor","van Bommel, L.L.","Infante Ferreira, C.A. (mentor)","2016","A Compressor Resorption Heat Pump (CRHP) is a potential contribution to energy reduction in applications in which waste streams are upgraded, with limited energy addition, into high value process streams for reuse in industry. Previous research concluded that a CRHP with a wet screw compressor is a suitable option for many applications. An ammonia/water mixture was found to be the most appropriate fit, in terms of thermodynamic behaviour, for such an application. Objective of this thesis was to develop an integration of a geometry model and a thermodynamic model suitable for further optimisation of the wet twin-screw compressor. The integration of the geometry model and the thermodynamic model was carried out in modelling tool Matlab/Simulink, with inclusion of the physical properties of the working fluid. The development of the integrated dynamic model was carried out based on research for a heat pump process with a pre-selected geometry and a homogeneous two-phase fluid. The existing geometry model was transformed from shaft rotation based to time based equations to achieve the dynamic model requirements and the possibility of modelling the process in Simulink. The geometry model provides inputs to the thermodynamic model that dynamically describes the wet twin-screw compressor from the suction phase through compression to the discharge phase. The thermodynamic model requires inclusion of physical properties of the fluid and these were added by importing the physical properties through Refprop via Fluidprop. Mechanical constraints of a wet twin-screw compressor inevitably lead to internal leakage paths that reduce the compressor efficiency. The leakage paths have been included together with factors for friction, flow loss, etc. to represent the process in a more realistic way. The integrated model has been validated with the calculated result by model case A and measured results from the experimental set-up by Zaytsev [1]. A number of variations have been applied to the integrated model as examples of how to evaluate options for improvements. Making use of the developed integrated model parameters can be varied to show the influence on the compressor. The evaluations used a specific set of boundary conditions from previous research, using the geometry specified by Zaytsev [1]. The effects of three input parameters on the output and efficiency were evaluated: rotor length, discharge port area and vapour quality. The main result of the evaluation is that per boundary condition, the inputs from the geometry model have to be adjusted to achieve an optimal design of the twin-screw compressor. Further research to find the optimal design can be done with the help of the model that was developed for this thesis.","screw compressor; CRHP; Compression resorption heat pump; Thermodynamic model screw compressor; compressor heat pump; two phase compressor","en","master thesis","","","","","","","","","Mechanical, Maritime and Materials Engineering","Process and Energy (P&E)","","","",""
"uuid:9a69b760-7d03-4d1d-b2cf-95d2a19cbe52","http://resolver.tudelft.nl/uuid:9a69b760-7d03-4d1d-b2cf-95d2a19cbe52","The ENergy Roof","Hoekstra, W.S.","Luscuere, P.G. (mentor); Schnater, F.R. (mentor); Van der Spoel, W.H. (mentor)","2016","This report describes the development of the ENergy Roof: a new concept for the Nul-op-de-Meter (NoM) renovation of single family dwellings in the Netherlands. The ENergy Roof consists of innovative technology, namely a solar assisted heat pump (SAHP) connected to photovoltaic solar panels that operates as evaporator (PV-DX). Furthermore the concept integrates all the required installation components in a single roof element which allows industrialisation, high production rates, price reduction and a one-day renovation, making a NoM more attractive. The purpose of this study is to develop the installation and control system of the ENergy Roof. A numerical MATLAB/Simulink model was constructed in order to simulate the system’s SCOP and annual electrical energy input to supply the space heating and hot tap water demand of the dwelling. This study has shown that the ENergy Roof is technically and financially feasible.","solar assisted heat pump; direct expansion; renovation; row house; thermal storage; renewable energy; nul op de meter; net zero energy; new stepped strategy","en","master thesis","","","","","","","","2018-07-01","Architecture and The Built Environment","Building Technology","","","",""
"uuid:75eea7d8-307f-45fc-92f9-1be3f648c405","http://resolver.tudelft.nl/uuid:75eea7d8-307f-45fc-92f9-1be3f648c405","Towards industrialized Zero Energy retrofit","Assad, A.","Kostantinou, T. (mentor); Klein, T. (mentor); van den Engel, P. (mentor)","2016","The goal to achieve the EU mission 20-20-20 through energy neutral buildings is a hot topic in Dutch building industry. Nowadays the focus lies in renovating the existing building stock to achieve the EU goal. Besides improving the energy efficiency a couple more issue needs attention. The acceptance of the occupants, the neighborhood and new business models. All these topics has one common related subject: The building industry needs to come with new building envelope solutions to achieve a less disturbance renovation process that fits in new business models. This research is part of consortium called the 2ndSkin. The purpose of this group is to find suitable solutions for the renovation of post war apartments in the Netherlands. The inhabitants are the central requirement. They are seeking for concepts that has minimal disturbance on the inhabitants and neighborhood, with minimal activities on site during and industrialized concept that could be use in a mass-implementation. The design is based on future potential building services, and the design is focusing only on the façade. The research has resulted in an integrated facade module that consist of two designs with existing technology been merged together. A design for the all-electric system mainly for the boiler to fit in the façade module and a façade/window element that carry these building services. This integrated design focus on a prefabrication and assemblage method of an integrated façade element. In order to provide acceleration on the building site and in assemblage process. Thereby disturbance on the inhabitants, on- site costs and transport will be minimalized. The outcome will be a higher safety, efficiency throw production till the assemblage process and potential amount of renovation as zero energy by using an all-electric. Besides that of course the façade element meets the stricter rules regard the energy efficiency.","Refurbishment; Retrofit; Zero Energy; Prefabricated; Heat pump","en","master thesis","","","","","","","","2017-01-31","Architecture and The Built Environment","Building Technology","","","",""
"uuid:e50fc686-e88b-492b-ba81-4e10aef14ed9","http://resolver.tudelft.nl/uuid:e50fc686-e88b-492b-ba81-4e10aef14ed9","Screening criteria for ILs used in NH3 based absorption heat pump systems","Wang, M. (TU Delft Engineering Thermodynamics); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","Groll, Eckhard (editor)","2016","This paper describes a properties-optimization work for the working fluids in NH3 / ionic liquid (ILs) based single-effect absorption heat pumps. The optimum parameters of the IL can be used as criteria in screening task-specified ILs, which play the role of absorbents, in absorption heat pumps. First, a 8-parameter thermodynamic model to calculate performances of a single-effect absorption heat pump cycle was proposed, which is based on the non-random two-liquid (NRTL) activity coefficient model for the vapor pressure and a linear function for the heat capacity. Then, experimental data on the vapor-liquid equilibrium (VLE) of solutions and heat capacities of the pure ILs were reviewed and fitted to obtain ranges of those parameters. Within certain limits, the values of parameters were optimized in the following step using the above proposed mode. The objective is a maximum system performance. The optimized ILs have low molecular weights, low specific heats and have high absorption capabilities.","absorption cycle; heat pump; ILs; NH3","en","conference paper","Purdue University","","","","","Paper no. 1690 http://docs.lib.purdue.edu/iracc/1690","","","","","Engineering Thermodynamics","","",""
"uuid:2e24e7e8-575e-4d1a-b5e4-0cdca49d9ab6","http://resolver.tudelft.nl/uuid:2e24e7e8-575e-4d1a-b5e4-0cdca49d9ab6","Metal-Organic Frameworks For Adsorption Driven Energy Transformation: From Fundamentals To Applications","De Lange, M.F.","Kapteijn, F. (promotor); Gascon, J. (promotor); Vlugt, T.J.H. (promotor)","2015","A novel class of materials, i.e. Metal-Organic Frameworks (MOFs), has successfully been developed that is extremely suited for application in heat pumps and chillers. They have a superior performance over commercial sorbents and may potentially contribute to considerable energy savings worldwide. Globally about 33 % of the energy consumption is used for heating and cooling of e.g. houses and buildings. Adsorption driven heat pumps and chillers are very well suited to reduce this energy consumption and can even use low-grade waste heat or sustainable solar energy in combination with environmentally benign working fluids (e.g. water). MOFs are porous crystalline materials built up from inorganic clusters connected by organic ligands in 1, 2 or 3 dimensions, and display a rich variety of topologies and can be functionalized in many different ways. They offer the materials scientist an outstanding platform to design new materials with superior properties. The described research has identified MOFs with sufficient stability against water, that show the desired adsorption behavior of water. These MOF-water pairs possess higher energy efficiency and working capacity than benchmark materials and may operate with a lower driving temperature. The selected MOFs can be coated (without binder) directly on heat-exchanger surfaces for a fast response. In short, there is a bright future for the application of MOFs in adsorption heat pumps and chillers with a large energy savings potential.","adsorption; MOFs; heat pumps; coatings; energy efficiency","en","doctoral thesis","","","","","","","","","Applied Sciences","Chemical Engineering","","","",""
"uuid:737def3e-897a-4153-8f57-791a8afa14a8","http://resolver.tudelft.nl/uuid:737def3e-897a-4153-8f57-791a8afa14a8","Mini-channel heat exchangers for industrial distillation processes","Van de Bor, D.M.","Vlugt, T.J.H. (promotor)","2014","In this thesis the technical and economic performance of compression-resorption heat pumps has been investigated. The main objective of this thesis was to improve the performance and reduce the investment costs of compression-resorption heat pumps applied in process industry. A model that is able to capture the performance of most heat pumps based on the Carnot and Lorentz COP by only knowing the temperature driving forces and estimating the compressor isentropic efficiency has been developed. By including an economic model for the investment costs of compressors and heat exchangers and including costs for electricity and heating, the model was capable of predicting the payback period for conventional systems. For larger systems of 10 MWth applied to a standard distillation column where compression-resorption heat pumps could use 50% of the lift as temperature glide, predictions show that such a heat pump will have a minimum payback period of approximately 3 years, while systems with a capacity of 2.8 MWth require about 5 years, clearly demonstrating the effect of system size. A more detailed model was implemented to investigate the performance of a compression-resorption heat pump applied to distillation processes in the Dutch industry. In this case, the heat pump could only make use of the temperature glide available in reboilers and condensers, which is much smaller than using the temperature glide in the columns. This is limiting the possible performance of the heat pump. The results showed that for most cases the performance was such that both energetic and cost advantages can be obtained with the implementation of such heat pumps. Further the model showed that in case of wet compression the inlet of the absorber should be a saturated vapor to reach maximum efficiency. To increase the performance of the compression-resorption heat pump and decrease the investment cost, the performance of mini-channel heat exchangers operating with a two-phase ammonia-water mixture was experimentally investigated. Initial research focused on the absorber performance in a mini channel annulus with a hydraulic diameter of 0.4 mm and a length of 0.8 m. Absorption side heat transfer coefficients in the range of 1000 to 10000 W m-2 K-1 were obtained for mass fluxes between 75 and 350 kg m-2 s-1 while the average vapor quality ranged from 0.2 to 0.6. The pressure drop varied between 0.2 and 1.6 bar under the given conditions and correlated with literature models within +25% / -25%. The heat transferred from shell to tube side ranged between 50 and 300 W. At low vapor qualities the heat transfer coefficient increases sharply between mass fluxes of 100 and 175 kg m-2 s-1. This behavior was less profound during experiments at higher vapor qualities. The tube side of the same heat exchanger was also investigated using the ammonia-water mixture during a desorption process. The tube side had a diameter of 1.1 mm and a length of 0.8 m. The obtained desorption side heat transfer coefficients lie in the range between 5500 and 10500 W m-2 K-1. The mass fluxes ranged from 150 to 300 kg m-2 s-1 and the average vapor quality ranged from 0.2 to 0.5. The heat transfer performance was well predicted by a model from literature after one of the empirical constants was adjusted. Due to ongoing deposition of debris in and in front of the channel the pressure drop increased over time such that a clear trend in pressure drop as function of mass flux and vapor quality could not be derived. The heat transferred in the heat exchanger under the given conditions ranged from 50 to 250 W. 116 One of the problems with mini-channel heat exchangers is upscaling. One tube can deliver up to 250 W, so for a system of 10 MWth 40 000 tubes are required. Further problems arise with flow distribution: one wants to distribute the flow such that each tube gets the same amount of liquid and vapor. As an intermediate step a heat exchanger was designed comprising of 116 tubes with a diameter of 0.5 mm. The shell side has a hydraulic diameter of 1.8 mm and an inner diameter of 21 mm. The flow distribution for single phase flows was first analyzed using a model which could capture the effects of contraction and expansions in the distributor and a similar design of the collector. Modeling the pressure drop in the shell side of a heat exchanger with the given geometry is complex. To simplify the approach, the Chilton-Colburn method has been chosen to be able to predict the friction factor in the shell side. The results from the model using water as working fluid showed that the flow is distributed evenly over all the tubes, deviations from the average were smaller than 0.1%. The heat transfer coefficients obtained with water as the working fluid on both sides lie between 750 and 850 W m-2 K-1 for mass fluxes between 5 and 30 kg m-2 s-1. The heat transfer model predicts 800 W m-2 K-1 for all heat transfer experiments, and the variation between the experiments can be merely seen as the deviations possible in the measurements and data reduction. Heat transfer experiments using the ammonia-water mixture have been conducted on this heat exchanger. When using this mixture in the shell side of the heat exchanger, it becomes clear that the heat transfer performance is lower compared to the same unit working with water in both shell and tube side. The shell side heat transfer coefficient is the limiting factor during the experiments. The overall heat transfer coefficient during the experiments ranged from 150 to 600 W m-2 K-1 for shell side mass fluxes from 2.7 to 8.1 kg m-2 s-1. The overall heat transfer coefficient now shows an increasing trend with mass flux, while during the water experiments the trend of increasing heat transfer coefficient with increasing mass flux remained within the error of the measurements. During all measurements the flow condition in the tube side was in all cases laminar flow. The ammonia-water mixture has also been put as the working fluid in the tube side of the heat exchanger in such a way that both shell and tube sides operate within the two-phase region. The overall heat transfer coefficients ranged between 300 and 1800 W m-2 K-1. The maximum attainable heat transfer coefficient increased because the mass flux could be increased from 8.1 kg m-2 s-1 to 16 kg m-2 s-1. Again the trend of increasing heat transfer coefficient with increasing mass flux was obtained. By increasing the inlet temperature of the absorber, the average vapor quality increases and the heat transfer coefficients also. Pressure drop ranged from 0.01 bar to 0.3 bar for tube side mass fluxes between 25 and 200 kg m-2 s-1, while the pressure drop on the shell side varied between 0.04 to 0.5 bar at mass fluxes between 2 and 16 kg m-2 s-1. During all two-phase measurements oscillations in flow rate and pressure drop have been identified, while they were stable during single phase flow. These oscillations are most likely caused by Taylor- and hydro-dynamic instabilities. During the desorption processes in the tube side of the heat exchangers the oscillations were larger, however, experiments","compression-resorption heat pump; mini-channel heat exchanger; ammonia-water; heat transfer coefficient; pressure drop","en","doctoral thesis","","","","","","","","2014-05-28","Mechanical, Maritime and Materials Engineering","Process and Energy","","","",""
"uuid:03399ff0-71be-43d9-9eff-2b10dc335cd8","http://resolver.tudelft.nl/uuid:03399ff0-71be-43d9-9eff-2b10dc335cd8","Energy Storage Strategies","Van Meijeren, W.M.","Luscuere, P.G. (mentor); Van der Spoel, W.H. (mentor)","2013","This report describes the development of energy storage strategies for short term Thermal Energy Storage in residential buildings with an air-source heat pump. Short term TES allows advanced integration of renewables because the associated mismatch between demand and availability is solved. The aim of the research was to develop control strategies which define a control sequence of heat pump operations with the purpose of minimization of primary energy input for space heating. This is achieved by more frequent utilization of free, low quality energy input. Exergy principles were used to assess the quality of energy. More free input will minimize the amount of work (high quality input) that is additionally required for the heat pump to generate the heating energy. In a conventional heat pump energy system, the installation is controlled without notion of exergetic optimal operation. This reference control strategy was compared to three optimization control strategies that were developed in this research, in combination with different storage capacities. The most advanced optimization strategy involves Greedy Optimal Control. This strategy defines optimal control of the installation based on estimates of future heat loads and future conditions for generation. First, a numerical MATLAB model was constructed in order to explore and compare the energetic potential of the strategies. This model showed that the optimization strategies result in significant primary energy saving when applied to large storage volumes that can only be realized within dwellings with latent TES. In latent TES, the high storage density during the phase change allows more compact storage. Secondly, the most potential storage configurations were translated into six use cases. The performance in terms of energy and exergy of these uses cases in combination with the most optimal control strategy was further simulated in a detailed TRNSYS model, and compared with the conventional control strategy. The aim of this model was to assess the influence of dynamic behavior of the heating emission system and temperature control on the performance of both strategies. It includes transient simulation of latent storage (macroencapsulated hydrated salt modules in a TES tank). This study has shown that the control strategy that optimizes operation and storage according to exergy principles, results in maximum 10% reduction of primary energy consumption for space heating compared to the reference situation.","short term thermal energy storage; predictive control strategies; exergy approach; phase change material; heat pump; variability renewable energy resources","en","master thesis","","","","","","","","2013-10-27","Architecture and The Built Environment","Architectural Engineering and Technology","","Green Building Innovation","",""
"uuid:dc13c65d-5a00-401a-bec3-5dc38c702967","http://resolver.tudelft.nl/uuid:dc13c65d-5a00-401a-bec3-5dc38c702967","Assessing the performance of ground source heat pumps in neighboring medium-size households","Alvarez Gallardo, M.D.P.","Korevaar, G. (mentor); Vardon, P.J. (mentor)","2013","The Master's programme Industrial Ecology is jointly organised by Leiden University and Delft University of Technology. This research project was done during an internship of 8 months completed with Royal Dutch Shell within the department of Future Energy Technologies of The Netherlands. It is focused on a case study of a medium size house (2202) situated in The Hague, NL and the neighboring households with the same characteristics along the same street. Homes in the Netherlands are likely to have their heat requirements fulfilled by conventional natural gas systems due to the relatively cheap cost compared to other systems (installation and investment wise) that could have a lower carbon footprint. However, innovative installations could make other more environmentally friendly systems as accessible as conventional systems. The Netherlands as one of the European member states have the goal of reducing CO2 emissions to accomplish their Kyoto targets; however, The Netherlands was not able to meet this target by 3.24% (target of 200.4 megaton CO2-eq). Besides, there is a general lack of financial incentives, making it in many cases an obvious decision to keep and use standard fossil fuel energy systems (both large- and small-scale) regardless of the environmental impact they may have. The building energy consumption sector provides a great opportunity and focus area for trying to reduce even more those emissions, and efforts have been made to introduce into the market more environmentally friendly systems. Until now, exploitation of geothermal shallow energy using a Ground Source Heat Pump (GSHP) has generally been limited to large commercial / industrial units. One reason for this is that the technology used for obtaining the geothermal energy and raising it to an appropriate temperature for the heat requirements of a typical house requires a big space for its installation which in turn proves to be a disruptive and complex process that requires the use of heavy and bulky machinery which immediately translates in a restriction for small homes. Innovations for installations of Ground Source heat pumps are starting to appear in the market, giving the possibility and the opportunity to install those systems in smaller areas, with less disruption and lower investment costs, although some concerns may arise when considering the thermal interference between the boreholes. This project examined the geological characteristics of the case study as determined by a Thermal Response Test (TRT) where parameters such as the thermal conductivity, the thermal resistance and the thermal diffusivity of the ground were obtained. Furthermore, the heat requirements of the test house were calculated with real data obtained during a year between 2012 and 2013 in order to determine the size of the system that would be required for each one of the houses assuming they all have the same demand throughout the year, having a peak demand for a winter day of 16 KW and an average demand of 10 KW in the winter months. Calculations of the length required of every Borehole Heat Exchanger (BHE) and the distance between them were made for the area of each house assuming no thermal interference. The first set of results indicated that a BHE length of 268 m would be needed, and with borehole thermal interference introducing a temperature penalty calculated with an analytical model, the length required increased to 332 m, 68 m more. After this a proposed design of borehole arrangement is suggested for the test house considering the space constraints. Calculations on the Economic and Environmental advantage from Ground Source Heat Pump (GSHP) compared to a Gas Boiler is done, taking into consideration two scenarios for the GSHP, 1) with a Seasonal Performance Factor (SPF) of 3.5 and 2) with a SPF of 3.0. Domestic gas and electricity price fluctuations over the past years were included, extrapolating this behavior for the years 2015 and 2020. Gas prices are considered to have changed 9% per year given the data from 1996 – 2013. Having extrapolated the prices, calculations are done on running costs and investment cost, to give the payback times when considering current power and gas prices for 2015 and 2020. The current situation (2013) seems the more expensive moment for having the system with a payback time of 24 years however a GSHP system in 2020 with electricity and gas prices following a 9% increase for gas prices would take just 8 years to have the investment back. For the environmental performance the Dutch footprint of power generation is calculated for the average predicted trends of different scenarios in the future for European power generation where GSHP with a SPF of 3.5 in 2020 seems to have the best Carbon Footprint advantage of all with 59% advantage of the compared systems. Recommendations are made in order to come up with connected scenarios of Dutch power and natural gas to have a coherent and timely understanding of GSHP and other renewable systems in the Dutch heating market for the coming years. Further recommendations are made in order to have a clear understanding on all the interrelated factors that have an impact on the efficiency, feasibility and performance of GSHP systems and how this research project could be broadened.","ground source heat pumps; renewable energy","en","master thesis","","","","","","","","","Technical University of Technology","Chemical Engineering","","Industrial Ecology","",""
"uuid:2c426196-6690-445f-8933-e3083a57b54c","http://resolver.tudelft.nl/uuid:2c426196-6690-445f-8933-e3083a57b54c","Design and analysis of a heat pump applied to old apartment buildings","Türkmen, Ö.S.","Infante-Ferreira, C.A. (mentor)","2012","Newly build buildings in the Netherlands are quite sustainable but are currently less that 5% of the total amount of buildings. Cooperative building societies are getting requirements from the European Union which they have to meet in a few years (Action Plan for Energy Efficiency: Realising the Potential). The target is to reduce the current energy consumption (heating and electricity) of buildings with 20% in 2020.The hypothesis is that with the correctly selected type of heat pump, with or without the combination with a CHP in the right proportions, a heating unit configuration exists with which mid to high temperature heating can be achieved in existing apartment buildings in the Netherlands, in a sustainable and cost effective way. Three heat pumps types were highlighted and explained, the Vapor Compression Heat Pump (VCHP), the Gas Absorption Heat Pump (GAHP) and the Compression Absorption Heat Pump (CAHP). Based on the yearly average temperature and the required temperature gain for the central heating water, the CAHP was the most economical option according to data from literature. The CAHP was investigated in more detail. When the heat pump was only able to deliver 336 kWth, the best investment and annual savings relation was obtained. With this configuration the heat pump is able to fully cover the 30-50ºC temperature range only. At higher required temperature ranges the heat pump would only deliver a part (336 kWth) of the total heating demand, up to 400 kWth would be delivered by a CHP and the remaining heating demand would be provided by conventional boilers. Despite that the Net Present Value (NPV) for the CAHP is 13% higher than the NPV for VCHP configuration, the latter is preferred. Since the CAHP is a rather new technology entering the market, more research is required in order to decrease the involved risk and uncertainties of the system.","heat pump; compression absorption heat pump; mini channel heat exchangers; old apartment buildings","en","master thesis","","","","","","","","","Mechanical, Maritime and Materials Engineering","Sustainable Process & Energy Technologies","","Energy Technology","",""
"uuid:79801e1e-ef19-4136-963d-c149f11bf56b","http://resolver.tudelft.nl/uuid:79801e1e-ef19-4136-963d-c149f11bf56b","Flexibilty of future energy scenarios","Laumans, C.J.","Gibescu, M. (mentor)","2011","If the Netherlands wishes to achieve an 80% CO2 reduction by the year 2050, technologies such as heat pumps and electric vehicles will be required to replace their fossil fuel burning counterparts. These technologies however have large consequences for electricity networks; not only will the amount of electricity transported over the networks increase, but so will the peak loads, pushing transformers and cables to their operating limits. This is a challenge that network operators are currently facing, and new methods are required to help them prepare for the future. In this thesis the flexibility of future energy technologies with the goal of limiting network loads in the Dutch low voltage electricity grid is investigated. ‘Flexibility’ refers to different variations, control strategies, and combinations of technologies that exist. Focus is placed on eight electric vehicle charging strategies and five types of electric heat pumps. Solar photovoltaics, electric hot water boilers, micro CHPs, and electric heaters as well as the effect of household insulation and thermostat setting are also investigated. The impact on the electricity grid is quantified by creating a testing environment in which the load of transformers and cables can be easily determined for any combination of market penetrations of the above technologies. Three representative low voltage networks are considered: A city, a village, and a countryside neighborhood. Calculations are carried out for a typical summer and winter day with 15 minute intervals. The technologies are modeled as Strand-Axelsson loads to take into account simultaneousness and accurately be able to predict the peak load of any number of users. The testing environment is validated by comparing the results to those obtained by Gaia, a software package specifically designed for carrying out electricity network calculations. Power demand profiles for all technologies are created using different modeling strategies. The electric vehicles are modeled based on mobility data of 50.000 Dutch citizens. Eight control strategies are modeled, examples are: uncontrolled charging, night time charging, and vehicle to grid. To model space heating technologies a Matlab model has been constructed that accurately predicts the heat demand of a household taking into account factors such as household type, insulation, thermostat setting, and outdoor temperature. With the model the power demand profiles of heat pumps and other heaters are created by modeling their control strategies. The electric vehicle and heat pump profiles are verified by comparing the results to measured data obtained from Alliander. The power demand profiles are entered into the testing environment and simulations are carried out. The impact of each technology on transformer and cable loads is quantified and the effects of flexibility are investigated. It is found that uncontrolled use of heat pumps and electric vehicles present problems for the electricity network: market penetrations as low as 20% could cause transformer loads to reach values above 100%. Flexibility options however do exist and can be used effectively to limit network loads. Electric vehicles offer the most flexibility since the charging times are the easiest to control. Heating technologies have limited flexibility but improving household insulation and using the right thermostat settings can reduce network loads. Micro CHPs combine very well with other technologies and can be very effective at limiting the loads caused by both electric vehicles and heat pumps.","flexibility; electricity grid; electricity network; heat pumps; electric vehicles","en","master thesis","","","","","","","","2012-02-01","Electrical Engineering, Mathematics and Computer Science","Electrical Power Engineering","","Sustainable Energy Technology","",""
"uuid:e1b40273-3855-4bda-892d-afffa37806e0","http://resolver.tudelft.nl/uuid:e1b40273-3855-4bda-892d-afffa37806e0","Hybrid adsorption compression heat pump systems: Configuration study & dynamic modeling","Van den Heuvel, C.M.","Infante Ferreira, C.A. (mentor)","2010","Evaluation of hybrid adsorption compression heat pump & heat transformer performance.","adsorption; compression; heat pump; heat transformer","en","master thesis","","","","","","","","","Mechanical, Maritime and Materials Engineering","Process & Energy","","Engineering Thermodynamics","",""
"uuid:5564f3f1-ae44-4366-a2b9-93fd76dd085d","http://resolver.tudelft.nl/uuid:5564f3f1-ae44-4366-a2b9-93fd76dd085d","Minimization of entropy production in diabatic distillation columns with integrated compression resorption heat pumps","De Kruif, J.","Infante Ferreira, C.A. (mentor); Kjelstrup, S. (mentor); Gross, J. (mentor)","2008","In recent years a trend towards more comfortable beds and mattresses has been developed. Water-filled warming mattresses have proofed to increase the comfort of beds. With the climate change, the number of nights with high temperatures during the summer is increasing. SBI has proposed to develop a water-circulated heating / cooling mattress to allow for comfort during both cold winter and hot summer nights. SBI has extended know-how about mattress heating systems. Cooling aspects are new to SBI. The introduction of such a mattress requires investigation of contact pressure / pressure points, comfort ratings in relation to cooled surface temperature, cooling requirements and heat exchanger surface design next to working principle requirements.","entropy production optimization; compression resorption heat pumps; heat pump integration","en","master thesis","","","","","","","","","Mechanical, Maritime and Materials Engineering","Process and Energy","","Engineering Thermodynamics","",""
"uuid:62fe7d42-d841-43c1-81ed-cab91f0b17c5","http://resolver.tudelft.nl/uuid:62fe7d42-d841-43c1-81ed-cab91f0b17c5","Design of A District Heating System Including The Upgrading of Residual Industrial Waste Heat","Falcao, P.W.; Mesbah, A.; Suherman, M.V.; Wennekes, S.","","2005","This study was aimed to evaluate the feasibility of using a waste heat stream from DSM for a District Heating System. A conceptual design was carried out with emphasis on the unit for upgrading the residual waste heat. Having reviewed heat pump technology, mechanical heat pump was found to be the best option for recovering the heat from the residual waste water. This heat pump (ammonia loop) combined with a natural gas fired heater will provide the districts with the required heat. The energy that can be extracted from the waste heat from DSM (100 TJ/annum) with a mechanical heat pump represents approximately 8% of the required energy input of the total Upgrading Unit. Therefore, additional energy input will be provided by a gas fired heater as combustion, which will also serve as a back up system. Heat pump technology is a sustainable method of heating and district heating system using heat pumps is a proven and well-known technology. It is widely used in Europe, Canada and the USA. Currently there is a district heating system in Norway using ammonia in a mechanical heat pump, which includes one airport and adjacent residential buildings and the design of another facility in the future has been considered. Moreover, nowadays environmental concerns require that the flue-gas emissions resulting from the supply of energy to processes should be minimized. By using the mechanical heat pump for upgrading the heat in this specific design, 4% emissions reduction will be achieved. The outputs of the design were established based on the required plant capacity and the results of the evaluation of the demand fluctuations and heat losses in the distribution system. Thus, the Upgrading Unit was designed for 923 Tera Joules per annum in order to compensate the heat losses in the pipeline network and supply the districts with a maximum annual demand of 780 Tera Joules. This capacity corresponds to approximately 11,000 houses being supplied with heat. The Upgrading Unit will be located as close as possible to DSM site in Delft, The Netherlands. The configuration of the distribution system and pipeline lengths were estimated based on the districts listed in a previous feasibility study. The economical plant life was assumed to be at least 15 years, considering continuous operation 24 h/day, 365 days/year. The total investment is MUS$29.3 and the production costs are MUS$20.3. They were calculated with Lang’s factored estimation method aiming to achieve ± 25% accuracy. As a result of the economic evaluation of this design, a negative cash flow of MU$6.1 was found. The Upgrading Unit might be profitable if one considers the possibility of using it as a power station in addition to the normal function as a heat producing plant. Decreasing the number of connected districts or collecting more waste water or waste water with a higher energetic value would be another option.","Mechanical Heat Pump; Chemical Heat Pump; Upgrading Unit; Waste Water; District Heating System","en","report","Delft University of Technology","","","","","","","2015-12-13","Applied Sciences","DelftChemTech","","","",""
"uuid:93b7fba3-fbfa-472a-80c1-460abc4beeb4","http://resolver.tudelft.nl/uuid:93b7fba3-fbfa-472a-80c1-460abc4beeb4","Heat pump for comfort, with added energy savings","Van de Graaf, A.","Cauberg, H. (contributor); Van de Dobbelsteen, A. (contributor); Van der Spoel, W. (contributor)","2005","The high-efficiency central heating boiler is about to reach the limits of its potential, so innovative insulation and other energy efficiency solutions are required, even though energy consumption in the Netherlands per household has dropped by 70% since 1986. Now that houses and offices are being fitted with increasingly efficient winter coats, an unexpected new problem has arisen, that of overheating. The savings through insulation are being squandered by air-conditioning units that are kept running all through the summer. According to Professor Ir. Hans Cauberg of the faculty of Architecture at Delft University of Technology, there is an efficient solution to this problem. A heat pump ensures that the cooling and heating processes are much more sustainable, and also more comfortable into the bargain. It will enable us to replace high-grade fossil fuels with sustainable, low-grade sources of energy such as ground water, geothermal energy, and waste heat. This will reduce the energy demand for heating by up to 40%, and for cooling by as much as 90%.Cauberg and his researchers have already prepared new design rules for some practical, but not inconsiderable problems such as condensation and acoustics. The heat pump will play an essential part in our future energy systems.","heat pump; low-energy house","en","journal article","Delft University of Technology","","","","","","","","","","","","",""
"uuid:22042cac-902f-481f-bc16-29dcd2e7e419","http://resolver.tudelft.nl/uuid:22042cac-902f-481f-bc16-29dcd2e7e419","Test loops for two-phase thermal management system components","Delil, A.A.M.; Heemskerk, J.F.","","1990","Two mechanically pumped two-phase test rigs were built at NLR in order to experimentally study critical issues of spacecraft two-phase thermal management systems: - a 5 kW, 31 mm ID, freon loop, focusing on the critical components of the ESA Two-Phase Heat Transport System. - a 30000 W, 4.93 mm ID, ammonia loop, to support the development of the ESA Capillary Pumped Loop Experiment (for the in-orbit demonstration of two-phase heat transport system technology) and to experimentally support two-phase thermal modelling and scaling activities. The rigs are described in detail. Typical test results are presented. Presented at SAE 901272 in the International Thermal Control Technology Session of the 20th Intersociety Conference on Environmental Systems, Williamsburg (VA), 9-12 July 1990.","two-phase flow; heat transfer; spacecraft temperature; temperature control; heat pumps; heat exchanges; performance tests; ammonia; freon; working fluids; spacecraft radiators","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:df41770e-639b-4d9c-ba39-6d5057b24603","http://resolver.tudelft.nl/uuid:df41770e-639b-4d9c-ba39-6d5057b24603","Preliminary experiments with an electro-osmotic heat pipe laboratory model","van den Assem, D.; Bunk, P.B.","","1983","Preliminary experiments have been performed with a laboratory model of an electro-osmotic heat pipe filled with ethanol. With dismounted electro-osmotic pump, the heat transport through the pipe and the temperature distribution along the pipe wall have been measured. The measurements have been performed as a function of the temperature difference across the pipe. The heat pipe performed like a CCHP imder wick limited operation conditions. Superheating of the ethanol in the evaporator caused relatively large variations' of the heat transport. With the electro-osmotic pump in operation, the heat pipe showed a fast gas production and corrosion of the electrodes of the electro-osmotic pump, whereas no measurable effect on the heat transport (< 2 W) could be observed. Most probably this disappointing result is caused by pollution of the ethanol.","electrokinetics; electro-osmosis; heat pipes; temperature; control; performance tests; boiling; osmosis; ethyl alcohol; heat transfer; heat pumps; models","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""
"uuid:f16fb8db-0150-44cc-bd32-f32a4deb7264","http://resolver.tudelft.nl/uuid:f16fb8db-0150-44cc-bd32-f32a4deb7264","Theory and design of conventional heat pipes for space applications","Delil, A.A.M.","","1976","The scope of this report is: - to give a short description of the possible operation principles and applications of heat pipes - to derive the governing equations for a model of a conventional heat pipe (including the limits to the heat transfer capability) - to describe the theoretical derivation of the formulae for the various thermal resistances associated with heat transfer in and by heat pipes and the equations necessary for the calculation of the resulting temperature distributions - to present a design philosophy and illustrate the design procedures - to compile data that are required for a proper heat pipe design - to survey typical space applications of heat pipes (both existing systems and possible future applications) - to indicate specific topics and problems areas associated with heat pipe use in space - to make a listing of heat pipe manufacturers, suppliers and users In this report restriction will be made to the single fluid, cylindrical - so-called conventional - heat pipe. The extension to more (fluid) components heat pipes and variable conductance heat pipes is foreseen to be presented in a report later. Calculations performed for heat pipe - fin radiator - combinations will be reported separately. Recommendations for future work are given as a result of the information that has heen collated in the report.","heat pipes; temperature control; satellite temperature; heat transfer; capillary flow; heat pumps; phase transformations","en","report","Nationaal Lucht- en Ruimtevaartlaboratorium","","","","","","Campus only","","","","","","",""