Simulation Analysis And Structure Optimization Of Parallel Air Cooling System For Electric Vehicle Battery Pack

Due to the current severe energy crisis and environmental pollution,the development of electric vehicles is an inevitable trend in today’s society.The performance of the power battery is the guarantee of the performance of the electric vehicle,and the good battery performance ensures the normal operation of the electric vehicle.Lithium-ion batteries have become widely used as power batteries due to their long life,no pollution and low self-discharge rate.Battery temperature directly affects battery performance,especially the maximum temperature and maximum temperature difference of the battery.Therefore,certain measures need to be taken to optimize the battery pack.In this paper,the method of computational fluid dynamics is used to study the temperature field of parallel air-cooled battery.First,the structure and working principle of the battery are introduced.The heat generation mechanism and heat dissipation mechanism of the battery are studied and the basic theory of computational fluid mechanics is explained to lay the foundation for simulation calculation.Secondly,the temperature field of the parallel air cooling system is simulated to obtain its maximum temperature and maximum temperature difference and the reasons for the temperature difference are introduced.The battery temperature difference is caused by differences in the distribution of air velocity and pressure drop in the cooling channel.Thirdly,the system is optimized by adding a secondary vent,and the effect of the location and size of the secondary vent on the heat dissipation performance is studied.The results show that the location of the secondary vent will affect the maximum temperature and the maximum temperature difference of the battery pack.The optimization effect of the battery pack is best when the secondary vent is facing the third cooling channel.The larger the width of the secondary vent,the better the heat dissipation performance.Fourth,the system is optimized by adjusting the battery spacing.when the inlet air velocity is 5m/s and the spacing adjustment step size is 0.1mm,the system needs 29 adjustments to achieve the best optimization effect.The maximum temperature difference is reduced by 85%.However,when the adjustment step is increased to 0.2mm,the optimization time is reduced by45%,and the maximum temperature difference is only 0.15 K higher than when the spacing adjustment step size is 0.1mm.The optimization time is significantly shortened,and themaximum temperature difference is only slightly changed,comprehensive comparison believes that 0.2 mm is the best value for spacing adjustment step.Change the inlet wind speed to study its impact on the spacing adjustment optimization,and find that the larger the inlet wind speed,the longer the optimization time required,and the optimization efficiency is reduced.Comprehensive analysis believes that 5m/s is the optimal air velocity of the system.