基于滤板调控风量的电池组风冷性能分析与优化

Analysis and optimization of air cooling performance of battery pack based on air volume regulated by filter plate

首先通过搭建测试平台,对18650锂离子电池单体容量、内阻和温升进行实验测试;再对比单体温升仿真与实验结果的一致性;最后建立了动力锂离子电池组模型,通过单因素分析和正交实验,研究过滤板自由面积比、电池间距、风速和电池距离底部间距对电池组最高温度和温差的影响。电池以1 C放电时得出结论:添加过滤板提升了电池组温度场一致性,过滤板自由面积比为0.1,0.9,0.9时电池组温差最小。最终通过正交实验得到最佳组合为风速6 m/s、电池间距4 mm、电池距离底部间距4 mm,比优化前最高温度下降了22.5%,温差下降了74.8%。

With the global trend of advocating environmental protection,energy conservation and emission reduction,and lowcarbon travel,electric vehicles have been vigorously developed.As the power source of electric vehicle,power battery pack is one of the core components of electric vehicle.At present,the mainstream battery used in electric vehicles at home and abroad is lithium-ion battery,which has the advantages of high power density and energy density,low cost,long service life and no memory effect.But its performance is greatly affected by temperature.Therefore,it is imperative to carry out thermal management of electric vehicles.Firstly,the capacity,resistance and temperature rise of 18650 lithium-ion battery were tested by building a test platform;then,the consistency between the simulation results of single temperature rise and the experimental results was compared;finally,the power lithium-ion battery pack model was established,through single factor analysis and orthogonal experiment,the effects of filter plate free area ratio,battery spacing,wind speed and battery bottom distance on the battery were studied.The influence of maximum temperature and temperature difference were studied.When the battery was discharged at 1 C,it was concluded that adding filter plate improves the consistency of temperature field of battery pack,and the temperature difference of battery pack was the minimum when the free area ratio of filter plate was 0.1,0.9 and 0.9.With the increase of wind speed,the maximum temperature decreased,temperature difference of battery pack first increased and then decreased.With the increase of battery spacing,the maximum temperature of battery pack first increased and then decreased,the temperature difference first increased,then decreased and increased at last.With the increase of the distance from the bottom of the battery,the maximum temperature of the battery pack first decreased and then increased.Finally,the best combination of 6 m/s,4 mm and 4 mm was obtained by orthogonal experiment,which decreased 22.5%and 74.8%respectively compared with the maximum temperature and temperature duffurence before optimization.