准二级压缩型电动汽车热泵空调系统制冷性能研究

Research on refrigeration performance of electric vehicle heat pump air-conditioning system with quasi-two-stage compression

针对普通电动汽车热泵空调系统在夏季高温环境中制冷时,排气温度过高,系统制冷性能衰减的问题,设计了一种采用中压补气技术的准二级压缩型电动汽车热泵空调系统,系统以R407C为制冷剂,并搭建了试验台。通过在标准焓差实验室模拟测试不同外界环境温度及改变压缩机转速情况下系统的制冷性能,并与普通单级压缩系统进行对比。研究表明:在制冷时,准二级压缩热泵空调系统在降低压缩机排气温度方面有很大优越性,在标准制冷外界环境30℃下,准二级压缩热泵空调系统制冷量和压缩机功率增加显著,分别提高了12.97%,4.92%,系统COPc提高了7.94%;当压缩机转速从2 000 r/min提高到6 000 r/min时,准二级压缩热泵空调系统制冷量和压缩机功率分别提高了6.01%~12.31%和2.06%~6.24%,系统COPc提高了0.63%~6.51%。

For the problem of too high exhaust gas temperature and decay of system cooling performance during the cooling of ordinary electric vehicle heat pump air conditioning system in high temperature environment in summer,a quasi-two-stage compression type electric vehicle heat pump air conditioning system with medium pressure vapor injection technology was designed.The system uses R407C as refrigerant,and a test bench was built.The refrigeration performance of the system was simulated and tested in the standard enthalpy difference laboratory under different ambient temperature and by changing the compressor speed,and compared with the ordinary single-stage compression system.The research results show that the quasi-two-stage compression heat pump air conditioning system has great advantages in reducing the compressor exhaust temperature during refrigeration.Under the standard refrigeration environment of 30℃,the cooling capacity and compressor power of the quasi-two-stage compression heat pump air conditioning system are increased by 12.97%and 4.92%respectively,and the system COPc is increased by 7.94%.When the compressor speed increases from 2000 r/min to 6000 r/min,the cooling capacity and compressor power of the quasi-two-stage compressor heat pump air conditioning system are increased by 6.01%~12.31%and 2.06%~6.24%respectively,and the system COPc is increased by 0.63%~6.51%.