Simulation and study of energy performance of solar assisted air-conditioning systems with dedicated outdoor air systems for hot and humid climate.
Chan, Kin Kuan.
Date of Issue2012
School of Mechanical and Aerospace Engineering
The increase in energy prices and effect of global warming has raised the concern about energy consumption reduction and efficiency improvement. In countries with hot and humid climate, application of desiccant cooling has the potential to reduce energy consumption as dehumidification plays a major part in air conditioning processes. However, the regeneration of desiccant dehumidifier requires heat and solar energy is one of the potential renewable heat sources for that purpose. In this project, TRNSYS simulation software was used to investigate the thermal comfort level and the energy consumption of 5 systems starting with conventional cooling system followed by addition of components such as desiccant wheel, heat wheel, solar thermal collector, hot water storage tank and absorption chiller. A typical office building was modelled in the TRNSYS software and the indoor condition was maintained at indoor air temperature between 22oC to 25oC and relative humidity between 55% and 65% during office hours. The simulation had shown that addition of dehumidifier was able to provide better dehumidification and handled latent load separately from chiller. The energy consumption of the chiller and pumps was found to be reduced by 15.4% but heating the regeneration air introduced increase in total energy consumption by 103.9%. The utilization of solar thermal collector was able to reduce the heating energy by 41.9% as Singapore receives consistent solar radiation due to its location near the equator. The overall energy consumption is found to be 35.8% more than conventional cooling system. Energy saving of 45.9% can be achieved when low grade heat such as waste heat is used for heating of regeneration air. In conclusion, the integration of solar thermal collector is feasible as a free and renewable heating source for regeneration of desiccant dehumidifier. The result of this simulation serves as a foundation for further investigation to improve energy efficiency in cooling systems.
DRNTU::Engineering::Mechanical engineering::Energy conservation
Final Year Project (FYP)
Nanyang Technological University