Thermal Field Simulation And Heat Dissipation Control Of Lithium-ion Power Battery Modules

The development of liquid cooling technology has promoted the gradual improvement of the thermal management system of the mini-channel liquid cooling battery.The purpose of thermal management is to ensure that each single cell in the battery pack works in a reasonable temperature range,while keeping the temperature distribution of the battery pack and battery modules as uniform as possible.First of all,a simulation model of lithium-ion single cell is constructed.The voltage and temperature characteristics of the battery are simulated and compared with reference experimental data to verify the numerical simulation method.And the validity of the simulation model lays the foundation for the subsequent thermal field simulation analysis of the battery module.Then,a method for analyzing the thermal behavior of the battery module combining single factor and orthogonal experiment is proposed.A simulation model of the liquid-cooled battery module is constructed in the computational fluid dynamics software.Under a constant discharge rate,the single factor analysis method is used to study the different cold plate structure,the number of mini-channels and the inlet mass flow rate on the thermal field distribution of the battery module and the influence of temperature indicators.Using simple and efficient orthogonal analysis and comprehensive analysis,the order of the factors affecting the thermal behavior of the battery module is obtained,and then the liquid cooling device structure with the best heat dissipation performance of the battery thermal management system is obtained.The results show that the cooling structure design significantly affects the high temperature area of the battery pack.At the same time,the cold plate structure design can significantly improve the temperature index of the battery pack.The optimal combination can control the maximum temperature below 302 K and reduce the maximum temperature difference to 3.52 K.Finally,based on the model of the optimal liquid cooling device structure obtained from the above analysis,in order to better analyze the heat dissipation control effect of the battery thermal management system,the width of the cold plate that affects the temperature distribution of the battery module and the mini-channel that affect the temperature difference.The interval and the mass flow that affect the temperature index are used as research factors.The influence of three factors on the heat dissipation performance of the battery module is analyzed.After orthogonal analysis,the optimal liquid-cooled battery thermal management system model is obtained,and an auxiliary cooling system is added to the optimal model to control the maximum temperature and temperature difference of the battery module below301.19 K and 2.74 K,respectively,which are 4.9% and 9.2% lower than the previous temperature indicators.The temperature index of the battery thermal management system is controlled within a reasonable range,which meets the requirements of the current lithium-ion power battery pack for temperature index under high discharge rate.The research strategy and analysis method proposed in this paper can further improve the heat dissipation performance of the battery thermal management system,and provide a reference for the heat dissipation control of the compact lithium-ion power battery pack with high discharge rate in engineering applications.