Design And Optimization Of Battery Thermal Management Based On Non-uniform Pin-fin Cooling Plate

In order to improve the life span and safety performance of power battery pack of new energy vehicles,this paper proposes a liquid cooling plate structure based on non-uniform pinfins,and carries out the design,optimization and experimental verification of the liquid-cooled thermal management system based on this structure.The structure can obtain better performance in temperature uniformity,power consumption and lightweight performance.Firstly,in order to verify the feasibility of the design of liquid-cooling plate with nonuniform pin-fins,the parameter influence analysis was carried out based on the established numerical model.Based on the theory of Bernardi battery thermogenesis,using experimental method to establish and verify the heat generation model of lithium polymer battery,the thermal-fluent coupling model of cooling plate and battery.The parametric study results show that in homogeneous fin design,simply increase/decrease fin diameter cannot reduce the maximum temperature,the temperature standard deviation of contact surface,power consumption and mass at the same time;In the non-uniform fin design,the scheme with fin diameter increasing or decreasing along the X direction has poor performance in temperature uniformity.However,the scheme with fin diameter increasing along the Y direction can obtain better performance: Compared with the parallel channel reference design,the control effect of the diagonal and edge temperature of the liquid cooled plate is obviously improved.The temperature in the central area is lower,and the mass,power consumption,temperature standard deviation and maximum temperature are reduced by 30.39%,11.2%,3.24% and 1.33℃,respectively.The parametric study results show that the design of the non-uniform pin-fin liquid cooling plate has feasibility and design potential.Secondly,in order to explore the optimal design of nonuniform fin liquid-cooled plates,multi-objective optimization was carried out.Two optimal design schemes of completely nonuniform and grouping non-uniform are proposed.Based on OLHS sampling method,CFD data of random samples were obtained by numerical simulation.The proxy model is built by using EBF elliptical base function method,and the proxy model is optimized by using multi-island genetic algorithm.By comparing the optimal scheme with the traditional parallel channel scheme,the simulation results show that the power consumption,mass,temperature standard deviation and maximum temperature of the optimal non-uniform fin liquid-cooled plate decrease by 29.84%,29.00%,17.43% and 1.039℃ respectively.Finally,in order to verify the non-uniform fin liquid cooling plate cooling effect,using additive manufacturing method,the optimal non-uniform fin liquid-cooled plate and the reference parallel channel liquid-cooled plate samples were fabricated,and the liquid-cooled circulation system was established.The liquid-cooling performance of the battery under 5C discharge condition was tested in an environmental test chamber.The experimental results show that the contact surface temperature of the optimal non-uniform pin-fin liquid cooling plate is lower than that of the parallel liquid cooling plate during the 120 s to 600 s of the discharge cycle,and the maximum temperature difference between the two is 0.9℃.At the end of the discharge,the temperature of the nonuniform fin liquid cooled plate is lower than 42℃.