基于风冷散热的锂电池热管理数值模拟研究

Research on numerical simulation of lithium-ion battery thermal management based on air-cooling

圆柱形锂离子电池布置方式和热物性参数对电池的热特性及安全性具有重要影响。首先建立了18650型LiFePO_(4)单体电池产热模型以及电池组散热模型,分析了排布方式、电池间距等电池模块几何参数以及径向导热系数等热物性参数对电池模块散热特性的影响。结果表明,电池的间距越大,其平均温度越低,温差越小,散热效果越好;单就冷却效果而言,叉排排布结构最优,综合考虑电池模块的能量密度和冷却效果,六边形排布结构最优;径向导热系数由0.2174 W/(m·K)增加到1.7174 W/(m·K)时,电池最高温度由306.15 K降低到302.90 K,减小了3.25 K,电池模块温度分布更加均匀。研究为基于风冷的锂离子电池组热管理系统结构的设计和优化提供了重要参考。

The configuration and thermos-physical parameters of cylindrical lithium-ion battery have a significant influence on its thermal characteristics and safety.This paper established heat generation model for single 18650 LiFePO_(4) battery firstly and then the battery module heat dissipation model was also developed.The effect of geometric parameters of battery module such as the arrangement and battery spacing,and thermal physical parameters on the heat dissipation characteristics of battery module were analyzed.The results show that the average temperature,the temperature difference and cooling effect of batteries decrease with the increase of battery space,were also improved.The staggered arrangement is the optimal structure as far as the cooling effect only.However,the hexagonal configuration shows an excellent compressive performance when the energy density of battery module is considered.When the thermal conductivity in radial direction increases from 0.2174 W/(m·K)to 1.7174 W/(m·K),the maximum temperature of battery decreases from 306.15 K to 302.90 K,which shows a 3.25 K reduction,and the temperature distribution in battery module becomes more uniform.This research provides an important reference for the design and optimization of air based thermal management system for battery module.