电动汽车电池包热电制冷系统的实验研究

Investigation on thermoelectric cooling system for battery packof electrical vehicle

为提高电动汽车动力电池包在高温环境下的安全性,设计并测试了一个热电制冷系统,采用了自行开发的肋柱型散冷器,安装了6个热电制冷模块,并采用循环冷却水进行热端散热。在测试中,当输入功率为273.6 W时,热电制冷系统的能效比随散冷风速和冷却液流量的增加迅速增加,然后趋于稳定,最佳的散冷风速和冷却液流量分别为2.5 m/s和33.3 mL/s,系统最大能效比为0.26。针对于一个储电量为36 kW·h的锂电动力电池包,电池包箱体内的温度在不同的产热率(50~200 W)下的降温幅度均超过20℃。动力电池包在200 W的产热率下,其内部温度从68℃降低到45℃以内,表明设计的热电制冷系统可有效降低动力电池包内的温度,从而提高电动汽车的安全性。

In order to promote the safety of the power battery pack in high-temperature environments for electrical vehicles,a thermoelectric cooling system was designed and tested.This system utilized a self-developed pin fin assisted cooling distributor,equipped with 6 thermoelectric cooling modules,and employed circulating cooling water for heat dissipation at the hot-ends.The coefficient of performance(COP)of the thermoelectric cooling system increased rapidly with the increase of the cooling air velocity and flow rate of cooling liquid,and then stabilized.The optimal cooling air velocity and flow rate of cooling liquid were 2.5 m/s and 33.3 mL/s,respectively.The maximum COP reached 0.26.For a lithium-ion power battery pack with a storage capacity of 36 kW·h,the temperature inside the battery pack case decreased by more than 20℃under different heat generation rates(50~200 W).The initial temperature of the power battery pack dropped from 68℃to below 45℃at a heat generation rate of 200 W,indicating that the thermoelectric cooling system designed in this study could effectively reduce the temperature inside the power battery pack and improve the safety of electrical vehicle.