Abstract: One enhanced and baseline heat pump air conditioning system(HPACS) for electrical vehicle(EV) are established including the new multi-flow micro-channel heat exchangers(HE) and the traditional fin-and-tube heat exchangers(HE), respectively. In order to provide theoretical guidance to the follow-up research of EV HPACS based on novel micro-channel design and frosting control, the performance differences are discussed between the two systems, the refrigeration and heating characteristics of both systems are compared under variable test conditions and the results show that volume of the indoor and outdoor heat exchangers decrease by 57.6% and 62.5%, respectively, effectively reduce air conditioner’s weight which contributes to the increase of EV’s Life mileage; at the same time, the enhanced system with compact HE could reduce air conditioner system’s charge by 26.5% which benefits to reduce the greenhouse effect. The cooling capacity and refrigeration coefficient of performance of the enhanced system reduce by 4.1%-10.7% and 1.7%-4.8%, respectively. It indicates that there are still some technical barriers require to be managed in case of multi-flow micro-channel HE applied in HPACS, for example, the flow path design of micro-channel HE, flow distribution and pressure drop in micro-channel HE. The heating capacity and heating performance coefficient of the enhanced system reduce by 1%-5% and 4.2%-9.7%, but the heating capacity per unit area increase by 16.7%-21.0%. The outdoor micro-channel HE will be frost when the outdoor temperature below 7 ℃, it immensely affects the heating capacity and the heating performance coefficient of enhanced system and demands to improve the frosting control strategy.

Key words: Coefficient of performance, Electrical vehicle, Fin-and-tube exchanger, Heat pump air conditioning, Microchannel heat exchanger