锂电池组高温节点空气冷却方案的数值模拟
Numerical Investigation for Hotspots of Stagger？？Arranged Lithium？？Ion Battery Stack with Air Cooling Strategy

为确保电动汽车动力锂离子电池组的安全、高效运行,建立了动力电池组三维数学模型,分别研究了送风速度、固定件热导率、导热翅片数量及热导率对动力电池组温度特性和流动特性的影响规律。研究结果表明:相比未考虑电池正负极固定件而言,传统环氧树脂(热导率为0？？2 W？m－1？K－1)作为电池正负极固定件显著提高了动力电池组内部的最高温度(约提高12 K),且随着雷诺数增大,2种情况的压降差异逐渐变大,说明未考虑电池正负极固定件的数学模型明显低估了动力电池组内部的最高温度和流动压降;当冷却空气在错列布置的动力电池组内部处于层流流动时,动力电池组整体散热性能达到最优的电池正负极固定件热导率为2 W？m－1？K－1,这一最优热导率值具有实际工程意义;导热翅片能有效改善动力电池组内部的温度分布,且可使电池组内部的空气流动压降增幅小于10％。
To ensure the safety and efficient operation of power batteries, a three？？dimensional numerical model of a stagger？？arranged battery pack was established to explore the effects of air supply velocity, number of fins, and thermal conductivities of fins and fixed parts on the thermal characteristics and pressure drop inside the battery pack. Numerical results show that the fixed parts made of traditional epoxy (λ=0？？2 W？m－1？K－1) between batteries more significantly increase the maximum temperature inside the battery pack compared with the case without fixed parts, and the temperature difference between these two cases is about 12 K. Moreover, the difference of pressure drop between these two cases gradually increases with Reynolds number. It is demonstrated that the numerical model of the stagger？？arranged battery pack without fixed parts distinctly underestimates the maximum temperature and pressure drop. As air coolant is of laminar flow inside the stagger？？arranged battery pack, the optimal thermal conductivity of fixed parts is 2 W？m－1？K－1. The temperature distribution inside the battery pack can be improved effectively by the fins associated with an increment of pressure drop less than 10％