Abstract: Outdoor refrigerant direct heat exchange system and outdoor coolant indirect heat exchange system are two typical new energy vehicle heat pump system architectures, the former has the characteristics of direct and high efficiency, and the latter has low cost and better refrigerant adaptability. For the two different architectures, the performance under typical operating conditions is analyzed by building AMESim simulation models. Get the following conclusions, compared with the coolant indirect heat exchange system and refrigerant direct heat exchange system, the decrease of cooling performance under cooling condition is more obvious than the decrease of heating performance; when temperature is lower, positive temperature coefficient (PTC) thermistor needs to supply heat advance, but the comprehensive coefficient of performance (COP) is still at a comparable level; COP is further reduced due to the influence of electric drive dissipating heat during cooling. The improvement measure is increasing the size of the radiator, or equipping passenger compartment and electric drive with independent radiators. Above analysis process and results provide a reference basis for the selection and design of system solution.

Key words: new energy vehicle; indirect heat pump; heat exchange system; secondary loop

摘要： 室外制冷剂直接吸放热系统和室外冷却液间接吸放热系统是两种典型的新能源汽车热 泵系统架构，前者有直接高效的特点，后者成本低、制冷剂适应性更好。针对两种不同架构， 通过建立 AMESim 仿真模型，分析了两者在典型运行工况下的性能表现，得到以下结论，冷 却液间接吸放热系统与制冷剂直接吸放热系统相比，在冷却条件下制冷性能的下降比制热性 能的下降更为明显；在温度较低时制热需要正温度系数（PTC）热敏电阻提前补充热量，但 综合性能系数（COP）仍在可比的水平；制冷时受到电驱散热的影响，COP 会进一步降低。 改进的措施有增大散热器的面积，或者为乘客舱和电驱配置各自独立的散热器。上述分析过 程和结果为系统方案选择和设计提供了参考依据。

关键词: 新能源汽车；间接热泵；吸放热系统；二次回路