L形脉动热管启动和传热特性的研究

Start-up and Heat Transfer Characteristics of L-shaped Pulsating Heat Pipe

针对电动汽车锂离子电池发热的问题,本文提出了上部加热/底部冷却型L形脉动热管。该脉动热管具有加热段长、冷却段和绝热段短的特点。研究了在供热量为10~30 W,冷却水温度为20~30℃,甲醇充液率为7.1%~21.2%条件下L形脉动热管启动与传热特性的影响。实验结果表明:随着充液率的增加,该脉动热管的启动温度呈增大的趋势,而热阻呈先减小后增大的趋势。并且随着加热量的增加,启动温度、启动时间和热阻均呈减小的趋势。当充液率为10.1%~14.1%时,在10~20 W的加热量和25℃冷却水条件下电加热板的平均温度保持在54.7℃以内,表明L形脉动热管能够充分保障电动汽车电池正常工作所需温度,且显示出良好的启动和传热性能。

In this study,an L-shaped pulsating heat pipe was proposed to address the thermal management problem of lithium-ion batteries in electric vehicles.A pulsating heat pipe has a long heating section,a short cooling section,and a short insulation section.The parametric effects on the start-up and heat transfer characteristics of an L-shaped pulsating heat pipe were studied,including the heating capacity of 10-30 W,cooling water temperature of 20-30℃,and methanol filling rate of 7.1%-21.2%.The results showed that as the filling ratio increased,the start-up temperature increased,and the thermal resistance first decreased and then increased.As the heating power increased,the start-up temperature,start-up time,and thermal resistance decreased.The maximum temperature of the heater was 54.7℃for a 14.1%filling ratio and 10-20 W heating power,indicating that the L-shaped pulsating heat pipe can effectively maintain the temperature required for the normal operation of batteries in an electric vehicle.