Research on Performance Optimization of Liquid Cooling and Composite Phase Change Material Coupling Cooling Thermal Management System for Vehicle Power Battery

The serpentine tube liquid cooling and composite PCM coupled cooling thermal management system is designed for 18650 cylindrical power batteries, with the maximum temperature and temperature difference of the power pack within the optimal temperature operating range as the target. The initial analysis of the battery pack at a 5C discharge rate, the influence of the single cell to cooling tube distance, the number of cooling tubes, inlet coolant temperature, the coolant flow rate, and other factors on the heat dissipation performance of the battery pack, initially determined a reasonable value for each design parameter. A control strategy is used to regulate the inlet flow rate and coolant temperature of the liquid cooling system in order to make full use of the latent heat of the composite PCM and reduce the pump’s energy consumption. The simulation results show that the maximum battery pack temperature of 309.8 K and the temperature difference of 4.6 K between individual cells with the control strategy are in the optimal temperature operating range of the power battery, and the utilization rate of the composite PCM is up to 90%.