堆叠式车载超级电容器热管理方式分析

Simulation of air-and liquid-cooled thermal management of stacked automotive supercapacitors

本研究使用COMSOL Multiphysics 6.0软件对堆叠式车载超级电容器建立了有限元模型,并且针对空冷和液冷两种不同的热管理方式分别建立了热模型以对比其热管理效果。首先,在相同的参数变化范围内,分别研究了空冷和液冷两种方式的超级电容器的最高温度与换热介质的初始温度、在入口处的流速以及超级电容器模组的发热功率之间的关系。结果表明,换热介质的初始温度越高,超级电容器的发热功率越大,则超级电容器的最高温度越高,而换热介质在入口处的平均流速越大,则超级电容器的最高温度越低,且存在一个临界流速1.5m/s,超过该临界值之后,二者的相关性将大大减弱。此外,基于参数化研究结果,设定相同的操作参数,深入分析了这两种热管理方式的换热过程,解释了本研究中空冷和液冷在高度方向上温度梯度方向相反的现象,并从最高温度与温差、温度分布和换热时间三个方面对比了二者的热管理效果。结果表明,液冷超级电容器的最高温度更低,温差很小,温度分布十分均匀,且换热时间远少于空冷超级电容器,热管理效果更好。

Finite element models were created for stacked automotive supercapacitors using COMSOL Multiphysics 6.0,and thermal models were developed for two different thermal management methods,air-and liquid-cooled,to compare their effects on thermal management.First,the correlations between the maximum temperature of air-and liquid-cooled supercapacitors and the initial temperature of the heat exchange medium,inlet flow rate,and heat generation power of the supercapacitor modules were investigated within the same parameter variation range.The results show that the higher initial temperature of the heat transfer medium and greater heating power of the supercapacitor lead to higher maximum temperatures of the supercapacitor.Conversely,a faster average flow rate of the heat exchange medium at the inlet results in lower maximum temperatures of the supercapacitor.A critical flow rate of 1.5 m/s exists,beyond which the correlation between flow rate and maximum temperature weakens greatly.Second,based on the parametric study results,the heat transfer processes of these two thermal management methods were analyzed in-depth by setting the same operating parameters.This analysis explains opposite heat gradient direction in the height dimension between air-and liquid-cooled methods.The comparison of thermal management effects of the two methodsincludes factors such as maximum temperature,temperature difference,temperature distribution,and heat exchange time.The results show that liquid-cooled supercapacitors exhibit lower maximum temperatures,smaller temperature differences,more uniform temperature distribution,and much less heat exchange time compared to air-cooled supercapacitors and have better thermal management effects.