大功率充电连接器相变冷却换热特性研究

Study of phase change cooling heat transfer characteristics of high power charging connectors

直流大功率快充技术可显著缩短电动汽车充电时间,缓解充电焦虑,然而在高电压、大电流下,充电连接器的温度短时间内急剧上升,将降低连接器使用寿命且易引发安全问题。为此,提出一种适用于大功率充电连接器的高效相变冷却技术,分别对单相和相变冷却性能进行数值建模分析,研究了冷却液种类、流量、套管厚度等参数对冷却性能的影响规律。结果表明,充电时长为5 min,加载电流为600 A时,采用40℃水单相冷却可将电缆温度降低至69℃,而采用R134a两相相变冷却则可将电缆温度降低至40℃以下。电缆温度随两相冷却液流量增加而降低,随套管厚度增加而增加,套管厚度相较冷却液流量对电缆温度的影响更为显著。

Direct current‑based high‑power charging(DC‑HPC)technology can significantly reduce the charging time of electric vehicles and therefore alleviates concerns about charging duration.However,the rapid temperature increase of charging connectors under high voltage and current poses a challenge,impacting their lifespan and safety.This paper proposes a phase change cooling technology for the high‑power super‑charging connectors.Through a comparative numerical analysis of the single‑phase and phase change cooling performance,the influence of coolant type,flow rate and casing thickness on the thermal behavior of the charging cable with active cooling are investigated.The results indicate that the cable temperature can be reduced to 69℃when using 40℃water as single‑phase coolant at a 5 min charging time and a 600 A loading current.In contrast,the two‑phase cooling coolant can further decrease the cable temperature to below 40℃.The charging cable temperature exhibits a decrease with increasing two‑phase coolant flow and an increase with rising coolant sleeve thickness.The coolant sleeve thickness has a more significant effect on cable temperature than the coolant flow rate.