Indirect cooling circuit via heat exchanger allowing optional heat recovery for the calorifier or cabin heating.

间接排气管水冷却方式，当水流经热交换器时，允许水流经任意方向通过水与废气热交换器或散热箱。

Studies on heat exchanger aluminum fin precoat of air conditioner were reviewed. Six types of precoat as well as the application of hydrophilic precoat were described.

回顾了空调机热交换器预层铝散热片的研究概况，介绍了6种类型预层散热片材料的基本情况以及亲水性预膜散热片的应用效果。提出了该课题今后的研究方向。