液冷板抑制锂离子电池组热失控蔓延性能及优化设计

Performance and design optimization of a cold plate for inhibiting thermal runaway propagation of lithium-ion battery packs

本工作通过数值方法研究了液冷板抑制锂离子电池组热失控蔓延的能力,并针对传统直流道液冷板在高温环境中应用出现的问题进行了优化设计。基于阿仑尼乌斯公式搭建了方形NCM电池组热失控蔓延模型,并与已有研究结果进行对比,证明该模型准确性较高。基于此模型进行后续液冷板抑制研究,其中液冷板置于电池之间。为了保证液冷板在高温环境中的可靠性,首先分析了板内流体温度表现。结果表明,当针刺电池发生热失控后,直流道液冷板在流速为0.01 m/s和0.05 m/s时流体最高温度超过沸点;流速为0.1 m/s时流体最高温度则低于沸点,且可以有效抑制电池组热失控蔓延。针对直流道液冷板流体温度过高的问题,采用变密度法对液冷板流道进行拓扑优化。分析了优化后液冷板的抑制性能,并与直流道液冷板进行对比。结果表明,优化后液冷板的抑制效果更优秀,且流体温度及液冷功耗均低于传统直流道液冷板:当流速为0.05 m/s和0.1 m/s时,流体最高温度相较直流道液冷板分别降低33℃和28℃,功耗分别降低17%和26%。

This study explores the ability of cold plates to inhibit the thermal runaway propagation of lithium-ion battery packs using a numerical method.Topology optimization was conducted to decrease the fluid temperature and power consumption of traditional cold plates with straight channels.The thermal runaway propagation model of a prismatic lithium-nickelcobalt-manganese oxide battery pack was built using the Arrhenius formula.To confirm the proposed model's high accuracy,its results were compared with those of existing models.A follow-up study was conducted based on this model,and a cold plate was placed between the batteries.To ensure the cold plate reliability in a high-temperature environment,the fluid temperature within the plate was first analyzed.The results showed that the maximum fluid temperature with straight channels exceeded the boiling point when the flow rates were 0.01 m/s and 0.05 m/s during the thermal runaway,inducing the danger of local high pressure.When the flow rate was 0.1 m/s,the maximum fluid temperature with straight channels was lower than the boiling point,and the cold plate inhibited the thermal runaway propagation of the battery pack.A variable density method was used to optimize the cold plate topology,aiming to improve the excessive fluid temperature of the cold plate with straight channels.The performance of the optimized cold plate was analyzed and compared with that of the straight channel plate.The results showed that the inhibition effect of the optimized cold plate was better.The fluid temperature and power consumption were lower than those of the traditional cold plate with straight channels;when the flow rates were 0.05 and 0.1 m/s,the maximum fluid temperatures were 33℃and 28℃lower than those of the cold plate with straight channels,and the power consumptions were 17%and 26%lower,respectively.