Performance Analysis And Field Synergistic Optimization Of Liquid-cooling Heat Dissipation For Lithium-ion Power Battery Module

In order to alleviate the increasingly serious environmental pollution and energy crisis caused by fossil fuels,the research and development of new energy vehicles have been carried out in major countries and regions around the world for the traditional automobile industry.Pure electric vehicles,hybrid vehicles,plug-in hybrid vehicles are considered as the most promising future traffic solutions.As the core of new energy vehicles and household energy storage devices,the perf ormance of lithium battery,including cycle life,discharge capacit y and safety performance,is greatly affected by working temperature.Therefore,in order to ensure the safety and efficiency of the device,the thermal management system of lithium batteries has been paid more and more attention.This paper combines the existing research results and the basic theory of heat transfer,and adopts the method of combining simulation with experiment.The main work and innovation of this paper are as follows:(1)The thermal model of the lithium battery cell was built.Based on the electrochemical working mechanism and internal structure of the lithium-ion battery,the required model parameters were obtained through experiments and references.The heat generation of the battery cell at different discharge rates was numerically simulated,and the temperature distribution of the battery cell under different heat transfer conditions was obtained.The model was verified by experiments.(2)Combined with the analysis of the cell thermal model,the basic structure of a liquid-cooling battery module was preliminarily designed.The temperature performance of the liquid-cooled battery model under multiple working conditions was analyzed.The temperature distribution of the battery module at different discharge rates,different coolant inlet flow rates and inlet temperatures was analyzed.(3)In order to optimize the heat dissipation performance of the initial module,the field synergy principle proposed by academician of superincrement element was used to analyze in detail the heat flow s ynergy of coolant in cooling plate cooling pipeline at different flow rates.The theoretical basis that the cooling performance of parallel multi-channel is better than that of single channel under the same flow rate was given by using field synergy theory,and the cooling performance of parallel 2-channel and 3-channel were simulated and analyzed under the same working condition,and the temperature distribution of parallel 2-channel and 3-channel cooling plates and battery packs after discharge were obtained.At last,the flow direction of coolant when the parallel 3 flow channel has the best cooling performance was pointed out.