基于液冷的圆柱锂离子电池热管理系统冷却性能研究

Study on Liquid Cooling Performance of Battery Thermal Management to Cylindrical Lithium-ion Battery

为了维持锂离子电池的工作温度,液冷技术因其传热系数高、能耗低等优点而得到广泛的应用,但其存在成本高、接触面积小等问题.本文提出一种新的并联细管冷却方案,采用Fluent软件对热管理系统进行仿真实验,分析了不同的水管数量、流速、导热片宽度和流向对热管理系统冷却性能的影响.研究表明:冷却管数量为4,入口流速在1×10^-6 kg/s至1×10^-3 kg/s范围内变化时,电池放电过程中最高温度逐渐降低,最大温差为2.6 K.随着导热片宽度增大和冷却水管数量增加,冷却液对电池冷却效果加强,电池最高温度和最大温差减小.此外,冷却液流向不同时,电池最高温度会略有减小,同时电池的正负极间温度更加均匀.本文提出的并联细管冷却方案不会增加电池包空间,同时增强冷却管与电池之间的热传导,使电池模组温度更加均匀.

In order to maintain the working temperature of lithium-ion batteries,liquid cooling technology had been widely used because of its high heat transfer coefficient and low energy consumption.However,the problems,including high cost and small contact area,restricted the application of liquid cooling.In this paper,a novel liquid cooling scheme parallel pipe was proposed.The software of FLUENT was used to simulate the thermal management system,and the effects of the number of water tube,the flow rate of coolant,the width of the heat conduction sheet and the flow direction of the thermal management system were analyzed.The results showed that when the number of cooling tubes was 4 and the inlet flow rate changed from 1×10^-6 kg/s to 1×10^-3 kg/s,the maximum temperature gradually decreased,while the maximum temperature difference increased first and then decreases,and the maximum temperature difference was 2.6 K in the process of discharge.With the increase of the width of the heat conducting sheet and the number of water tubes,the cooling effect of the coolant was enhanced and the maximum temperature and the maximum temperature difference of the battery were reduced.Meanwhile,when the coolant flow direction was different,the maximum temperature of the battery was slightly reduced,and the temperature between the positive and negative poles of the battery became more uniform.when the coolant flow direction is different,the maximum temperature of the battery will be slightly reduced,and the temperature between the positive and negative poles of the battery would be more uniform.According to the cooling scheme proposed in this paper,the space of the battery pack was maintained,and the heat conduction between the cooling tubes and the battery cell was enhanced,by which the temperature of the battery module was made more uniform.