锂离子电池组结构热仿真

Thermal simulation analysis of a lithium-ion battery group

锂离子电池组的热特性对于电池组的运行维护具有重要影响。将单体电池热模型简化为均匀发热体,减少仿真流程中的计算量,针对锂离子电池组进行热仿真分析,分析其结构的合理性,并通过实验验证其准确性。利用绝热加速量热仪(accelerating rate calorimeter,ARC)采集锂离子电池的热特性参数,利用简化的电池单体热模型,选择风冷作为冷却方式,通过CFD(computational fluid dynamics)以及CAD(computer aided design)软件建立锂离子电池组的热模型并进行求解,分析电池组内部流场分布、电池组运行时的温度数据,最后通过样机实验测试验证仿真结果的准确性。该电池组在0.5 C恒流充放电条件下,电池模拟温度与实验测试温度变化趋势一致,电池组模拟最高温度与实验测试温度误差0.9℃,电池模拟温差与实验测试温差误差0.2℃。

The thermal characteristics of the lithium-ion battery packs are of considerable significance for their operation and maintenance.In this study,a cell thermal model is simplified into a uniform heating unit to simplify the computation during the simulation process.The novel model structure is validated through thermal simulation using a lithium-ion battery pack,and its accuracy can be experimentally verified.Further,the thermal characteristic parameters of the lithium-ion cells are acquired via an accelerating rate calorimeter.Subsequently,a lithium-ion battery pack thermal model is constructed and solved using computational fluid dynamics and computer-aided design programs based on the simplified cell thermal model and considering an air cooling scenario.The internal flow field distribution and in-service temperature data of the battery pack are analyzed.Finally,the accuracy of the simulation result is verified through a prototype experiment.When charged and discharged at a constant current of 0.5C,the simulated temperature of this battery pack exhibits the same variation profile as that exhibited by the experimental measurement with an error of 0.9℃ being observed with respect to the maximum temperature and 0.2℃ being observed with respect to the temperature difference in case of the simulation and experimental results.