Print Email Facebook Twitter Analysis of the impact of adjustments to the on board HVAC design by time domain simulations Title Analysis of the impact of adjustments to the on board HVAC design by time domain simulations Author Osté, J.G.A. Contributor Hopman, J.J. (mentor) De Vos, P. (mentor) Pijnen, G.J.A. (mentor) Konings, H. (mentor) Faculty Mechanical, Maritime and Materials Engineering Department Marine & Transport Technology Programme Mechanical Engineering - Mechanical Systems and Integration Date 2016-01-18 Abstract The system for heating, ventilation and air conditioning (HVAC) on board of passenger related ships is one of the biggest energy consumer. The system is vital to the comfort of the crew, passengers and can improve reliability of equipment. Since fuel prices keep rising and green credentials of a ship become more important it is necessary to have insight into the efficiency of the HVAC system. When a ship designer wants to analyse the potential of energy efficient measures, other HVAC layouts or needs to evaluate how the current system will behave in off-design conditions the behaviour of the system in actual service conditions is required. Power demand varies in time due to time dependent variables like ambient conditions and internal heat loads. These aspects can be investigated through time consuming on-site measuring, but this project investigates the possibility to generate this research data by time domain simulations with an HVAC system simulation computer model. The purpose of this project is to develop a tool which provides the ship designer easy access to data of energy consumption and HVAC system behaviour in different service conditions and operational areas, in order to analyse energy efficiency in the early design stage and to gain system understanding to enable the designer to act as smart customer towards HVAC experts and suppliers. The HVAC computer model is constructed from separate component models, each describing a physical discernible part of the HVAC process. These components are verified during extensive verification procedures, to make sure the model behaves as expected. The HVAC system of the AMELS 272 superyacht, a central variable air volume (VAV) configuration with reheating, is used as a benchmark for this project. A test case consisting of one air handling unit (AHU) and two conditioned rooms with dedicated local control is built from the component models. The benchmark simulation showed that the model is able to generate data of the energy consumption and the behaviour of the HVAC system and the separate components within a matter of seconds. From this data the energy consumption of the reheaters proved to be substantial during a one day cycle for every climate. The nominal local flow rate is determined based on the worst case design conditions and because the minimum flow rate of local supply air is limited at a certain percentage of the nominal flow rate, the local supply air provides too much cooling capacity the majority of the day. Therefore a substantial amount of reheating is required. From the system understanding gained with the results from the benchmark simulation several suggestions arose for case studies to increase the efficiency and demonstrate the capabilities of the model to investigate the impact of adjustments in the HVAC system. By raising the AHU supply temperature with one degree up to 14% energy reduction can be realized, with the consequence that less dehumidification occurs in the AHU, resulting in higher indoor relative humidity. Lowering the flow rate limit proved to reduce the energy consumption with up to 9% for decreasing the limit with 5%, with the consequence that possibly insufficient air mixing is provided to have homogeneous temperature distribution throughout the room. Increasing the recirculation ratio reduced the energy consumption with up to 3% for every 5% extra recirculation air. Because of the high reheating demand a measure to lower the solar heat gain through glass did not result in energy savings. To quantify the potential of the case studies more research needs to be conducted to the boundaries of the consequences of these energy efficient measures. If the consequences are found to be unacceptable, more research can be performed to measures to cope with the consequences. Subject HVACsimulationssuperyacht To reference this document use: http://resolver.tudelft.nl/uuid:010e4bdb-6162-4bb4-a7e2-7c9796281532 Embargo date 2021-01-18 Coordinates 52.0017, 4.3725 Part of collection Student theses Document type master thesis Rights (c) 2016 Osté, J.G.A.