Analysis of Coolant Flowing and Heat Transfer Performance in High Voltage Heater System

A method for performance calculation and experimental method of a high voltage heater system in electric vehicles is proposed. This system is critical for the thermal management of electric vehicle batteries, especially in low-temperature environments. It provides essential heating support to maintain optimal battery performance and safety, thereby improving overall efficiency and reliability.Firstly, heater outlet temperature and pressure drop of the heater are used as metrics to compare simulation results with experimental data, thereby validating the established model. Then, simulations are performed on two heater flow channel configurations: a cavity flow channel and a cooling fin flow channel. It is observed that the latter significantly reduces the heating plate temperature. This reduction enhances the protection of heating elements and extends their operational lifespan, demonstrating the advantages of incorporating cooling fins into the flow channel structure. The optimization variables for multi-objective optimization include the fin unit length, fin height, fin thickness, fin width, and spacing between two adjacent rows of fins. The optimization objectives include pressure drop, heat transfer efficiency, and heating plate temperature. Multiple sets of sample schemes comprising the variables are generated using the Latin hypercube sampling method. For each combination of variables, the objectives is estimated using Fluent software. Based on the estimated relations of variables versus objectives using the Latin hypercube sampling method, a response surface model is constructed. Finally, the NSGA-II algorithm is used to determine the optimal fin structure scheme. The optimized design results show that a significant reduction in pressure drop, heat transfer efficiency is enhanced, and heating plate temperature is reduced compared to the original model, confirming the effectiveness of the optimization.