Structural Optimization And Performance Analysis Of A New Energy Battery Cooling Plate For A Passenger Car

With the advantages of environmental protection and energy saving,new energy vehicles will become the development direction of automobile industry in the future.Power battery provides power for the operation of electric vehicles,and its performance has an important impact on the power performance,service life and stability of electric vehicles.In the process of driving,the battery will produce a lot of heat,and the accumulation of heat in the battery pack will lead to the rise of battery temperature.When the maximum temperature of the battery exceeds the optimal working temperature range,the performance of the battery will decline,and in serious cases,it will lead to vehicle fire and explosion.Therefore,it is necessary to carry out thermal management of automotive power battery to ensure that the battery temperature is in the appropriate working temperature range.In this paper,combined with the enterprise cooperation project,taking a new energy passenger car battery cooling plate as the research object,using three-dimensional software to establish the power battery heat generation model,and combined with the experiment to verify.Then,combined with the topology optimization of cooling structure,the channel layout of the initial cold plate is improved.Finally,the thermal characteristics of the optimized cold plate are studied,and the influence of different factors on the heat dissipation performance of the cold plate is analyzed.The main research work is as follows:(1)The structure,heat generation and heat transfer principle of the power battery used in the target vehicle are studied and analyzed,and the heat generation model of the battery is established.The temperature rise experiment and Simulation of power battery under different discharge rates are carried out.The simulation results are compared with the experimental data.The results show that the error between the two results is less than 5%,and the simulation results are basically consistent with the experimental data.It is confirmed that the heat generation model is accurate and available.(2)In order to get the heat dissipation performance parameters of the initial cold plate,the simulation analysis of different discharge rates of the power battery module and the initial cold plate was carried out.It is found that the maximum temperature of the battery is higher than the optimal working temperature range when the cold plate is not added,and the temperature of the battery module is successfully reduced to the optimal working range after the cold plate is added.However,the temperature difference of the battery is too large under2 C discharge condition,which is more than 5 ℃ of the maximum allowable temperature difference of the battery.(3)Traditional cold plate design is based on the designer’s own experience,which is lack of theoretical basis.In order to make the cold plate design more reasonable,the topology optimization of cooling structure is analyzed.Based on the variable density method,two optimization examples of uniform heat generation region are designed,and the distribution structure of heat conduction material is obtained through the analysis of the examples,which provides theoretical support for the later cold plate design.(4)Combined with topology optimization of cooling structure,the initial cold plate was improved and optimized,and then the optimized cold plate was simulated and analyzed.The effects of ambient temperature,coolant temperature and coolant flow rate on the performance of cold plate were studied.The results show that the performance of the optimized cold plate has been greatly improved,the maximum temperature of the battery has been successfully reduced,the temperature consistency has been improved,and the optimal temperature of the battery has been achieved.