| With the development of new energy automotive industry,the electric vehicles will gradually replace the traditional car.Lithium-ion batteries are widely used in the power batteries pack because of their high power density,long life and no memory effect.But during charge and discharge cycles,the batteries will produce large amounts of heat due to the reaction heat and the joule heat.Because of the limitation of the layout of the power battery pack,the heat dissipation condition is poor,which leads to the accumulation of the heat of the battery and causes the temperature rising.Therefore,the design of the power battery must satisfy the requirements of heat dissipation capability of the battery pack.This paper intends to study the heat dissipation of the single battery and the battery box.The heat dissipation structure of the battery and the battery box is optimized based on the maximum temperature rising,the average temperature,the temperature variance and so on.As to the heat dissipation structure of the single battery,the paper uses the variable density based topology optimization method and principle,and uses the finite element software Comsol,establish the single battery cooling topology model aiming at the goal of average temperature and the temperature variance,and with the constraint of the amount of the cold plane.At last,optimization scheme is determined by comparing the topological results of the two goals.For the optimization of dissipation structure of the battery box,the paper will establish the model of the liquid cooling,calculate the heating distribution in the extreme conditions by using software Fluent.Then the goal of the minimium average temperature and minimum battery temperature variance is set to optimize the battery cooling structure,which can reduce the average temperature of the battery and improve the uniformity of the battery temperature.In addition,radiator model is established and docked with the battery box model.Transient simulation for the temperature changing of the cooler and battery box is done using sofhtware Fluent,to make sure that battery box cooling model will be more closed to the actual situation. |
