Simulation study of propane refrigerant for heat pump water heaters

Heat pumps are becoming an essential part of our daily lives due to their high efficiency when compared to the traditional water heating systems. The choice of refrigerant is one of the main issues for the HPWHs. Hydrofluorocarbons (HFCs) chlorofluorocarbons (CFCs) are still being used, but global warming and ozone depletion remain problems due to their high GWP and ODP. Propane R290 is found to be a better and cheap alternative which could be uyilised for HPWH systems due to its better GWP and ODP. This study involves the numerical simulation via IMST-ART simulation software. The software was used to simulate propane R290 which was compared with refrigerants R134a and R407C. To analyse the COP of R290, compressors with different stroke displacement and input power were also modelled on the software. The results indicate that refrigerant R290 was able to achieve better COP as the ambient temperature goes higher, whereas the COP for refrigerants R134a and R407C decreases at higher ambient temperature. The results for different input power compressor indicated that the compressor with the lower input power was able to achieve higher COP, when compared with the higher input power compressor.