结构因素对动力电池用多孔平板热管性能的影响

Effect of Structural Factors on Performance of Multi-Channel Flat Heat Pipe of Power Battery

摘要:

基于VOF（volume of fluid） 两相流模型，采用计算流体力学（CFD）方法对某款锂离子电池用多孔平板热管的性能进行了仿真研究。分析表明：方孔结构比圆孔结构具有更大的蒸发/冷凝传质率和管内平均流速，6方孔平板热管的当量导热系数比原始6圆孔结构提升了30.5%；热管当量导热系数随内部孔数的增加而增加，但性能提升幅度渐渐变小；在蒸发段参数不变的前提下，热管的性能是由冷凝效果及冷凝段回流效率共同决定，热管冷凝段长度的增大并没有实质性改变热管的冷热端温差，此时所定义的当量导热系数并不能反应热管的实际性能。

Abstract:

Using the CFD simulation method based on the volume of fluid (VOF) two-phase flow model, the characteristics of a multi-channel flat heat pipe developed for a lithium-ion battery was studied. Compared with the circular channel structure, the rectangular channel structure has a higher mass transfer rate of condensation/evaporation and a higher average velocity in the channels. The equivalent thermal conductivity of 6 square-channel flat heat pipe is 30.5% larger than that of the original structure with 6 circular channels. The heat pipe performance increases with the increase of channel number, but the increasing rate slows down gradually. With the fixed geometric parameters and the power input of the evaporation section, the performance of the multi-channel flat heat pipe is determined by the combined effect of condensation in the condensation section and the return efficiency of condensate liquid flow. As a result, the increase of the length of the condensation section does not substantially change the temperature difference between the two ends of the heat pipe, and the equivalent thermal conductivity does not reflect the effect of the length of condensation section on the performance of the heat pipe.