Abstract: In order to widen the operating range in low-temperature of the heat pump airconditioning system and improve the thermal efficiency of the heat pump air-conditioning system further, this paper presents a heat pump air conditioning system with the function of waste heat recovery, which is based on the ordinary heat pump air-conditioning in mass production. This paper analyzes the system working principles in detail, and designs the technical scheme of the system with the heat pump air-conditioning compressor, the waste heat recovery exchanger, the electromagnetic valve and the electronic expansion valve as the main parts. The emphasis is put on the three important working modes of the waste heat recovery, including the waste heat of the motor recovery, the waste heat of the motor and the battery recovery, and the waste heat of the air recovery. Aiming at the electronic expansion valve which is the core part of the system, a proportion integration differentiation (PID) control method based on the exhaust target temperature is developed, which can improve 40% of the thermal efficiency compared to the ordinary heat pump air-conditioning without waste heat recovery.

Key words: Electric vehicle; Heat pump air conditioner system; Heat recovery; Electronic expansion valve

摘要： 为了拓宽热泵空调系统的低温使用环境温度范围，进一步提升热泵空调系统的热效率，文章基于公司某款纯电动汽车，在当前已具备量产条件的普通热泵空调基础上，提出了一种具备余热回收功能的热泵空调系统，详细分析了工作原理，设计了以热泵空调压缩机、余热回收换热器、电磁阀和电子膨胀阀为主体的系统技术方案，重点说明了余热回收换热器单独 回收电机余热、余热回收换热器同时回收电机和电池余热、余热回收换热器和车外换热器同 时回收空气余热的三种重要工作模式，针对系统的核心部件电子膨胀阀，制定了基于排气目 标温度的比例-积分-微分（PID）调节控制方法，实车验证了该系统节能效果，相比当前已量 产的普通的无余热回收的热泵空调有 40%以上的提升。

关键词: 电动汽车；热泵空调系统；余热回收；电子膨胀阀