纯电动汽车动力电池组液冷系统优化及冷却性能研究  

Study on Optimization and Cooling Performance of Liquid Cooling System for Pure Electric Vehicle Power Battery Pack

作　　者：王延宁[1] WANG Yanning(Guangdong University of Science and Technology,Dongguan 523083,China)

机构地区：[1]广东科技学院,广东东莞523083

出　　处：《重庆理工大学学报（自然科学）》2020年第6期83-89,共7页Journal of Chongqing University of Technology：Natural Science

基　　金：国家自然基金青年基金项目(51705189)。

摘　　要：散热问题是影响电动汽车电池寿命以及行车安全性的重要因素。针对目前电动汽车动力电池导热系数较低、液冷系统结构不合理等问题,对18650型电池的散热问题进行研究。分析了电池放电过程中的生热特性,建立电池组模型,对其放电过程进行热仿真。根据仿真结果中存在的问题,对冷却系统结构进行优化设计。同时,为研究冷却液初始温度对液冷系统冷却性能的影响,分析了不同冷却液初始温度下电池组温度变化情况。仿真结果表明:优化后的液冷系统结构可有效提高电池组的导热效率,在放电开始后272 s内使电池组内最大温度差达到标准,传热率提高了47. 7%。在20~30℃范围内,随着冷却液温度的升高,放电终止时电池组内的最大温度差逐渐降低,达到标准温差时间有效缩短,在采用逐步降低冷却液温度的方法后可进一步提升液冷系统的散热能力。Aiming at the problems of low thermal conductivity and unreasonable structure of liquid cooling system of electric vehicle power battery,the heat dissipation of 18650 batteries was studied.Firstly,the heat generation characteristics of the battery during discharge are analyzed,and the battery pack model is established to simulate the discharge process.According to the problems existing in the simulation results,the cooling system structure is optimized.At the same time,in order to study the influence of initial temperature of coolant on cooling performance of liquid cooling system,the temperature change of battery pack under different initial temperature of coolant was analyzed.The simulation results show that the optimized structure of the liquid cooling system can effectively improve the thermal conductivity of the battery pack.Within 272 seconds after discharge,the maximum temperature difference in the battery pack reaches the standard,and the heat transfer rate increases by 47.7%.The maximum temperature difference in the battery pack decreases gradually with the increase of coolant temperature in the range of 20~30℃,and the time to reach the standard temperature difference is shortened.The cooling capacity of the liquid cooling system can be further improved by gradually reducing the coolant temperature.

关 键 词：动力电池 液冷散热 结构优化 冷却液 

分 类 号：TM912[电气工程—电力电子与电力传动] U469.72[机械工程—车辆工程]