To improve the existing ejector heat pump air conditioning (EHPAC) system for electric vehicles

indoor and outdoor heat exchangers were designed to be separated from the front and rear rows

and ejectors were added to achieve cascade evaporation and recover the expansion work. The performance of the system was thus improved. The influences of the indoor and outdoor temperatures of the vehicle on the cooling and heating performances of the EHPAC system under summer and winter conditions were experimentally studied. The verification results show that the use of ejectors can significantly improve the heating performance of heat pump systems in vehicles. Compared with the traditional heat pump air conditioning (THPAC) system for electric vehicles

the cooling and heating performances of the EHPAC system are better at different vehicle indoor and outdoor temperature conditions. The cooling capacity increases by approximately 21.5%–35.7%. The cooling coefficient of performance (COP) increases by approximately 13.1%–21.7%. The heating capacity increases by approximately 4.4%–14.5%

and the heating COP increases by approximately 11.3%–18.3%. This also indicates that the performance of the EHPAC system is more sensitive to the indoor temperature of the vehicle than the outdoor temperature.