Heat transfer characteristics of liquid cooling system for lithium-ion battery pack

To improve the thermal uniformity of power battery packs for electric vehicles, three different cooling water cavities of battery packs are researched in this study: the series one-way flow corrugated flat tube cooling structure (Model 1), the series two-way flow corrugated flat tube cooling structure (Model 2), and the parallel sandwich cooling structure (Model 3). Based on the fluid-solid coupling method, this study analyzes the cooling performance of the three models, including thermal uniformity, heat dissipation, and pressure loss. At a high discharge rate, compared with the series cooling system, the parallel sandwich cooling system makes the average temperature and maximum temperature of the battery pack decrease by 26.2% and 26.9% respectively, and the battery pack temperature difference decreases by 62%, and the coolant pressure loss decreases by 95.8%. The results show that the Model 3 overcomes the temperature accumulation caused by the series flow of coolant and achieves a better level of thermal uniformity while improving the heat dissipation and pressure loss performance. The research provides scholars and industries with a reference for upgrading thermal management and improving the stability of the power battery pack for electric vehicles, which has both theoretical and practical significance.