电动汽车锂电池模块化热管理系统的设计及实验研究

A design scheme of modular thermal management system of lithium batteries for electric vehicles is proposed to solve the problem that the lithium batteries of electric vehicles are easy to cause degradation of battery performance under high temperature conditions, and even lead to thermal runaway. The system is designed with 20 staggered cylindrical batteries. Six cooling cells with coolant channels are arranged between the batteries. The cooling fluid flowing in the cooling cells can quickly remove the heat generated by the batteries during operation and thus ensure the lithium batteries to work within the appropriate range of 25-40 ℃. The designed system is used to simulate and to optimize the influences of coolant flow rate and pipe connection on the cooling performance of the batteries module. An experimental platform is built for verification based on the optimization results. Experimental results show that the increase in the coolant flow rate effectively improves the cooling efficiency, but the selection of flow rate should balance the advantages and disadvantages of cooling effect and power consumption. The maximum temperature and temperature difference in parallel connection are reduced by 7.55℃ and 6.74℃ respectively compared with those in series connection. This indicates that parallel connection can improve the heat dissipation performance of the entire modular thermal management system of batteries, and when the number of battery packs is large, parallel mode should be adopted. Parallel connection manner shortens the time of wide temperature fluctuation, and reduces the impact of excessive temperature fluctuation on the batteries.