To solve the problem of low energy efficiency and driving mileage reduction when pure electrical vehicles are heated using electric heating

two kinds of heat-pump air-conditioning system

i.e.

with four-way valve and four magnetic valves

were designed

and performance and reliability were investigated experimentally. The charge amount of refrigerant in the two systems was scientifically determined based on the subcooled temperature and refrigerating capacity

and was 500 g and 700 g

respectively. The results show that the refrigerating capacity and heating capacity under normal conditions can reach 2 kW in both heat-pump air-conditioning systems. In addition

the heating capacity under low-temperature conditions drops to 800 W in both heat-pump air-conditioning systems

and the four-way valve causes a phenomenon called “gas bypass” under a vibration condition of 3 g @ 33 Hz

which easily leads to instability of the system

even damage to the compressor; however

the heat-pump air-conditioning system using four magnetic valves works steadily under the same vibration conditions.