Abstract: Direct heat pump can improve the electric energy utilization efficiency and comprehensive thermal management level of electric vehicles. However, in the spring and autumn conditions that require heating and dehumidification, due to the heat coupling of the evaporator and the internal condenser of the direct heat pump, there may be a problem of discontinuity of the outlet air temperature in theory, that is the "outlet air temperature gap". In this paper, a typical direct heat pump system is studied. The upper and lower boundary of the outlet air temperature under the condition of 10~30 ℃ is tested in the enthalpy difference laboratory. The existence of the outlet air temperature crack is confirmed. Through analyzing the factors such as ambient temperature, compressor performance, front inlet air volume and air inlet temperature of heating ventilation air conditioning, a series of optimization countermeasures are proposed and validated, which provides a possible solution for solving the outlet air temperature gap of direct heat pump.

Key words: Electric vehicle; Direct heat-pump; Outlet air temperature gap; Heat pump system circulation mode; Heat coupling

摘要： 采用直接热泵技术可以提升电动汽车的电能利用效能和综合热管理水平。但在春秋季 等需要采暖、除湿的工况下，由于直接热泵的蒸发器和内置冷凝器的热量耦合在理论上可能 会出现出风温度不连续的问题，即“出风温度裂隙”。文章研究了一种典型的直接热泵系统， 在焓差实验室测试了 10～30 ℃春秋季工况下出风温度的上下边界，确认了出风温度裂隙的存 在。通过分析环境温度、压缩机性能、前端进风风量、空调箱进风温度等因素，提出了一系 列优化对策，并进行了有效性验证，为解决直接热泵的出风温度裂隙提供了可能的解决方案。

关键词: 电动汽车；直接热泵；出风温度裂隙；热泵系统循环模式；热量耦合