新能源汽车单体锂离子电池三维散热模型仿真

Three dimensional heat dissipation model simulation of single lithium ion battery of new energy vehicle

研究采用30个单体磷酸铁锂型电池组成锂离子电池组,经过电池参数选取、设定电池排列与网格划分的模拟环境后,建立单体锂离子电池三维热模型,通过锂离子电池导热微分方程和其物理参数计算完成锂离子电池散热特性相关参数计算,模拟测试新能源汽车锂动力电池散热特性。实验结果表明:锂离子电池最高温度与放电倍率成正比,当放电倍率为2.5C时的电池最大温差是放电倍率为0.5时电池最大温差的7.33倍;不同散热风速情况下,电池串行最大温度曲线数值始终高于插行温度,电池的串行排列散热性能低于插行排列;当散热风速相同且离子电池放电倍率为1.5C时,单向吸风散热方式效果高于单向吹风散热方式;不同通风方式下,当通风周期时间延长时,往复通风方式较单向通风方式散热效果差;电池最高温度与其开缝宽度成反比例关系,电池开缝宽度越小其散热性能越好。

In this paper, a lithium-ion battery pack is composed of 30 single lithium iron phosphate batteries. After selecting battery parameters and setting the simulation environment of battery arrangement and grid division, a three-dimensional thermal model of single lithium-ion battery was founded. The parameters related to the heat dissipation characteristics of lithium-ion battery were calculated via the heat conduction differential equation of lithium-ion battery and its physical parameters. The heat dissipation characteristics of lithium power battery of new energy vehicle were simulated and tested. The experimental results show that the maximum temperature of lithium-ion battery is directly proportional to the discharge rate;When the discharge rate is 2.5 C,the maximum temperature difference of lithium-ion battery is 7.33 times that of lithium-ion battery when the discharge rate is 0.5;The value of the serial maximum temperature curve of the battery is always higher than the plug-in temperature at different heat dissipation wind speeds, and the heat dissipation performance of the serial arrangement of the battery is lower than that of the plug-in arrangement;When the heat dissipation wind speed is the same and the discharge rate of ion battery is 1.5 C,and the effect of one-way air suction heat dissipation is higher than that of one-way air blowing heat dissipation;When the ventilation cycle time is prolonged, the heat dissipation effect of reciprocating ventilation mode is worse than that of unidirectional ventilation mode(under different ventilation modes). The maximum temperature of the battery is inversely proportional to its slit width. The smaller the slit width of the battery, the better the heatdissipation performance.