锂电池热管理系统多物理场耦合数值模拟研究

Numerical simulation of multi-physics field coupling of lithium-ion battery thermal management system

电池组温度对锂离子电池的工作性能和使用寿命等特性影响很大。为研究电池放电倍率以及冷却液流速对电池热管理系统温度分布的影响,本文以18650锂离子电池为研究对象,采用有限元方法仿真分析了在不同放电倍率、不同流动速度下的BTMS温度分布情况,分析造成温度和温差过高的原因。研究结果表明:当冷却液流动速度相同时,放电倍率越大,电池单体温度越高;当冷却液速度在0~0.05 m/s范围内时,增大冷却液流速,电池组最高温度降低越显著;当流速大于0.05 m/s后,冷却液流速越大,电池单体间温差越小,但冷却效果也在逐渐变差。

The temperature of the battery pack has a great impact on the performance and service life of lithium-ion batteries.In order to study battery discharge ratio and cooling liquid flow speed on temperature distribution of battery thermal management system,a 18650 lithium-ion battery is chosen as the research object,and the finite element method is used to simulate the temperature distribution of BTMS at different discharge rates and flow rates,aiming to find out the reason to cause high temperature and temperature difference.The results show that when the coolant flow rate is the same,the larger the discharge magnification is,the higher the temperature of the battery cell is.However,when the coolant speed is in the range of 0 to 0.05 m/s,with the increase of coolant flow rate,the maximum temperature of battery pack decreases significantly.When the flow rate is greater than 0.05 m/s,the larger the coolant flow rate is,the smaller the temperature difference between the battery monomer is,but the cooling effect is gradually deteriorated.