Optimization method of phase change energy storage device for electric vehicle batteries based on numerical simulation

Phase change energy storage devices are extensively utilized in latent heat thermal energy storage and hold significant potential for application in the thermal management of automotive batteries. By harnessing the high-density energy storage capabilities of phase change materials to absorb heat released by the batteries, followed by timely release and utilization, there is a substantial improvement in energy efficiency. This approach aligns with the objective of promoting low-carbon environmental protection and presents an opportunity to enhance the operational performance and energy utilization efficiency of electric vehicle batteries in low-temperature conditions. However, the thermal conductivity of medium and low temperature phase change materials is poor, leading to its inefficient utilization. This paper focuses on optimizing the structure of a phase change heat exchanger in a phase change energy storage device to improve its performance. A basic design of the phase change heat exchanger is used as an example, and fin structure is added to enhance its heat exchange capabilities. A predictive surrogate model is built using numerical simulation, with the dimension and number of fins as design variables, and heat flow density, heat absorption and release time as optimization objectives. The fitted design variable distribution surface is used to select any number of design points for verification. The deviation between prediction results and simulation results is less than 4%. Compared with the original design, the optimized design better meets functional requirements. The structural optimization method outlined in this paper offers a cost-effective approach to accurate prediction results, demonstrating practical engineering implications for the design of phase change energy storage devices and thermal management of electric vehicle batteries.