Experimental evaluation of cycle performance for new-developed refrigerants in the electric vehicle heat pump systems

Abstract

The heat pump is increasingly popular for the electric vehicles (EVs), however, there are no appropriate refrigerants. To provide long-term and environmental-friendly refrigerants in the heat pump for EVs, a test bench that can investigate the performance of an R410A prototype was built. The drop-in tests of three refrigerants (M1, M2, M3) developed previously with ultra-low GWP were carried out. The cooling and heating cycle performance were measured for R410A and alternative refrigerants. Experimental results showed the optimal refrigerant charge for the alternatives was less by 36-44% than that of the R410A system. For M1 and M2, the heating capacities showed 85-99% of those of the R410A system, with COP being 94-112%; the cooling capacities showed 94-109% of those of the R410A system, with COP being 99-107%. M3 showed much better COP than that of R410A system. The pressure drops were lower than those of R410A up to 21.6%, 25% and 55.7% for M1, M2 and M3, respectively. Furthermore, the alternative refrigerants showed better temperature match with air in the evaporator and condenser, the irreversible loss in the heat exchangers was also analyzed. This research will contribute to providing appropriate refrigerant substitutes in heat pump for EVs.