Establishment Of Heat Dissipation Mathematical Model And Parameter Optimization Of Vehicle Power Battery Module

With the increasing problems of air pollution and resource shortages,more and more countries have begun to vigorously promote the development of electric vehicles.The core of electric vehicles is power battery,and the performance of power battery affects the quality and user experience of electric vehicles.The temperature has a significant impact on the performance of the power battery.If the heat generated by the battery is not released in time during high current discharge,the battery will experience problems such as life degradation,burning or even explosion.Therefore,in order to maintain the temperature within a safe range,designing a reasonable Battery Thermal Management System(BTMS)is of.great significance for improving the performance and life of the power battery.First of all,this paper establishes a flow resistance model based on the pressure drop loss equation and the flow loss equation,which can calculate the air flow rate in the cooling channel;based on the energy conservation equation,establishes a heat transfer model to calculate the battery temperature.The flow resistance model and the heat transfer model constitute the heat dissipation mathematical model of the battery thermal management system through the connection of the convective heat transfer coefficient,and the Computational Fluid Dynamics(CFD)method is used to verify the reliability of the heat dissipation mathematical model.Then,based on the mathematical model of heat dissipation,sensitivity analysis is carried out to study the influence of inlet flow,battery spacing,divergence angle,divergence width,convergence angle and convergence width on the power consumption,maximum temperature,and maximum temperature difference of the battery thermal management system,and then clarified the optimization parameters of the battery thermal management system.Finally,on the basis of the Non-dominated Sorting Genetic Algorithm-3(NSGA3)with elite retention strategy,the method of differential mutation is used to establish the Non-dominated differential genetic algorithm(NSGA3_DE).Regarding power consumption,maximum temperature and maximum temperature difference as the optimization goals,with battery spacing,divergence angle,convergence angle,convergence width and inlet flow rate as parameter variables,the NSGA3_DE algorithm is used to optimize the parameters of the heat dissipation mathematical model.The results show that compared with the original BTMS,the optimized BTMS power consumption is reduced by 16.7%,the maximum temperature difference is reduced by 60.7%,and the maximum temperature is reduced by 3.4K.