动力锂离子电池模块散热结构仿真研究

摘要

Due to the heat dissipation problem of power lithium-ion battery packs, 12 series-10A∙h lithium iron phosphate battery packs were taken as the research object. A three dimensional thermal simulation model for lithium ion battery packs was established based on the finite element commercial software COMSOL MULTIPHYSICS and validated by infrared imaging technology to analyze the influence of the air forced convection cooling and cold plate cooling on the heat dissipation of battery packs. The result shows that with the convection heat transfer coefficient increasing from 5 W/(m2·K) to 100 W/(m2·K), the center temperature of packs reduces only 0.2 K, but the temperature difference reaches 10 K. It can be concluded that the ability about lowering temperature of forced convection cooling is limited, and the forced convection cooling aggravates the temperature uniformity of packs. The maximum and minimum temperatures of battery pack with 5C discharge rate are 318.91 and 317.19 K, respectively, which is superior to forced convection cooling. It can be concluded that the cold plate cooling can balance the pack temperature. Increasing the thickness of cold plate and the number of external cooling fins can reduce the temperature and temperature uniformity of battery packs, but it is not obvious under natural convection cooling.%针对目前动力锂离子电池模块散热困难的问题，以12串10 A∙h磷酸铁锂动力电池为研究对象，基于COMSOL MULTIPHYSICS平台建立其三维热仿真模型，并应用红外成像技术进行验证；定量分析不同工况下空气强制对流冷却和冷却板冷却对电池模块散热性能的影响。结果表明：空气强制对流冷却降低电池温度的能力有限，且造成电池模块温度均匀性变差。对流换热系数从5 W/(m2·K)变化至100 W/(m2·K)进行5C放电时，电池模块中心温度仅降低0.2 K，电池温差达到10 K；冷却板冷却具有平衡电池模块温度场的作用，其降温效果和温度均匀性均优于空气冷却时的。5C放电时，电池模块最高温度为318.91 K，最低温度为317.19 K；空气强制对流冷却时，增加冷却板厚度和外部散热翅片的数量都能够降低电池模块温度和均匀性，但在自然冷却条件下该变化不明显。