18650型锂离子电池模组的液冷散热效果

Liquid cooling heat dissipation effect of 18650 type Li-ion battery module

为改进动力电池模组的散热效果,以18650型锂离子电池为研究对象,设计“S”形液冷管道散热结构。在混合功率脉冲特性(HPPC)内阻测试的基础上建立电池模组热模型,用STAR-CCM+软件仿真分析冷却液流速、通道数量、流体流向和液冷管连接方式对散热性能的影响。散热效果不会随着流速的增加而无限提升,在流速增大到0.50 m/s时,模组的最高温度稳定在28.20℃;通道数量对散热性能的影响很小,四通道的最高温度仅比一通道下降0.10℃;流体流向可以促进散热,相邻流道采用不同流向(ABAB流向)相比四个流道采用单一流向(AAAA流向)可使最高温度下降2.30℃;相比于串联结构,采用液冷通道并联结构时,最高温度仅降低0.10℃,但流体最大压降可下降70%。

To improve the heat dissipation effect of power battery module,18650 type Li-ion battery was taken as the study object,the“S”shaped liquid cooling tube heat dissipation structure was designed.Based on the internal resistance test of hybrid pulse power characteristic(HPPC),the thermal model of battery module was established.Through STAR-CCM+software simulation,the influence of coolant flow rate,channel number,flow direction and connection mode of liquid cooling tube on the heat dissipation performance was analyzed.The heat dissipation effect would not be unlimited increasing with the increase of flow rate.When the flow rate was increased to 0.50 m/s,the maximum temperature of module was stable at 28.20℃.There was little effect on heat dissipation performance with the number of channels.The temperature with four channels was decreased only by 0.10℃than that with one channel.The heat dissipation effect could be improved with the flow direction.The maximum temperature with different flow direction between adjacent channels(ABAB flow direction)was lower than that with single flow direction of all four channels(AAAA flow direction)by 2.30℃.Compared with the series structure,when adopting the parallel structure of liquid cooling channel,the maximum temperature could be decreased by only 0.10℃,but the maximum pressure drop of the fluid could be decreased by 70%.