Design of a Heat Exchanger with Thermal Storage using PCM

Energy efficiency is a key goal for the Quooker system. To further increase the energy efficiency of the Quooker system, this study investigates a possible heat integration system where the waste heat from the refrigeration cycle for chilled drinking water is implemented to preheat water before entering the boiling water reservoir.<br/>Due to...

Boundary layer flashback prevention by active control: Combining process and control engineering knowledge

Hydrogen is a promising fuel for both reducing greenhouse gas emissions and being used as an energy carrier for renewable energy sources. The adaption of hydrogen instead of natural gas as a fuel in gas turbine combustors introduces additional challenges regarding flame stability. One instabilities is boundary layer flashback. This phenomenon...

The dryer section of a paper machine: Modelling and simulation

Currently, the paper producing industry is a significant energy consumer and contributes to the excessive greenhouse emissions. In order to become carbon neutral by 2050, it is evident that the paper industry must become more sustainable as well. Most of the energy is consumed in the dewatering process. Therefore, optimizing this process is key...

Investigations on NOx emissions from a turbulent non-premixed bluff body stabilized flame

In this thesis work, we strive to describe and apply the modelling methodology for simulating a turbulent jet diffusion flame stabilized behind a bluff body by applying flamelet generated manifold (FGM) model and steady diffusion flamelet model for predicting the pollutant emissions from the flame. The flame under consideration is a CH4/H2 (1:1)...

Using Artificial Intelligence for turbulent combustion modelling: Simplifying the conventional lookup tables

In reacting flows, detailed chemistry computations are usually avoided precomputing the thermochemical quantities as functions of a reduced set of variables such as the Flamelet Generated Manifold (FGM) approach[34]. Although it mitigates the calculations of detailed chemical mechanism, the memory requirement associated to store the lookup table...

Development of pure-rotational coherent Raman spectroscopy on hydrogen for applied flame thermometry

Work is presented on a novel hybrid fs/ps two beam CARS application for spatiotemporal gas phase hydrogen thermometry, capable of sampling at a rate of 1 kHz. The aim of the research is to assess the feasibility of directly probing hydrogen for accurate temperature measurements in a combustion environment. Typically, nitrogen is used in applied...

Numerical modelling of flame flashback in premixed tube burners with turbulent flow and high hydrogen content

This study presents the numerical modeling of boundary layer flame flashback in premixed tube burners with turbulent flow and high hydrogen content. The modeling approach is based on a RANS turbulence model and a flamelet combustion model using a flame surface density approach in combination with multiple turbulent flame speed correlations to...

Boundary layer flashback prediction for high hydrogen flames at gas turbine burner geometry and operating conditions

The idea of using hydrogen as a medium for storing excess renewable energy is gathering momentum but to deliver, several technological advances are required. One of the main challenges is boundary layer flame flashback (BLF) as a key operability issue for low NO_x premixed combustion of hydrogen-enriched fuels; thus design of tools to...

Comparative study of different Radiation, Turbulence and Chemistry models for the simulation of a Lab-scale MILD combustion furnace

Flameless combustion, or MILD combustion is a technology that enables stable combustion with high efficiency while maintaining very low NOx and soot emissions. It is characterized by uniform heat flux and can be achieved when fuel and preheated oxidant jets are mixed into a strong recirculating flow. It is a complex process which combines...

Sensing ultraviolet light emission from hydrogen flames: Flame detection and flame monitoring in CO2 emission free domestic boilers

As a contribution to the decarbonisation of domestic heating, the graduation project investigates the feasibility of the application of UV sensor technology for flame detection and flame monitoring in hydrogen-powered domestic gas boilers. The research includes empirical studies and an analytical approach to describe influences on the sensor...

Indirect estimation of mean vorticity from polarized emission of nanoparticles in turbulent duct flows

Optical measurement techniques are widely used in fluid mechanics to measure quantities like velocity, vorticity, and temperature. They are usually non-intrusive visualization techniques that provide a major advantage by not influencing the flow properties. Most of the developed measurement techniques estimate vorticity by computing the...

Waste heat recovery from quenching towers

Steel plants are one of the largest sources of waste heat. Waste heat recovery throughout the steelmaking process is not a new phenomenon. One of the sources of waste heat is found in the coke plant. Cokes are an essential part of steel production. During the coking process hot cokes are cooled down. Most coke plants in the world traditionally...

Synchronization in Rowing: Thesis on the effect of crew synchronization on rowing performance

On all levels of rowing, a general rule is that you have to row together. Rowing together has no clear-cut definition. However, it is known that each rower has his or her own style, which can be registered in movement patterns and force curves. The big question is how to combine these individual styles such that the crew works together in the...

RANS-FGM simulation of n-heptane spray flame in OpenFOAM: A new implementation of flamelet generated manifold to account for enthalpy loss with detailed reaction mechanisms

The efficient and clean combustion of liquid fuels is a fundamental requirement in the design of future energy systems. Simulation plays a more and more important role in the design of such burners. In this work the spray combustion simulation approach introduced by Ma (2016) is improved, and validated against the CORIA Jet Spray Flame database ...

Chemical Reactor Network for LDI Combustor: CRN development and Analysis of Different Fuels

Prediction of emissions from combustion systems is a complex problem involving the coupling between the flow field and chemistry. CFD analysis is the most commonly employed approach. However, it has the drawback that a very high computational cost prevents the use of detailed chemistry models. This master thesis, which focuses on NOx emissions,...