Study On Heat Dissipation And Energy Consumption Performance Of Liquid Cooling Plate Of Lithium Battery

The safety,endurance performance,service life and other characteristics of new energy vehicles are directly determined by the power battery.The quality of battery performance has become the focus of restricting the vigorous development of the new energy vehicle industry.Batteries are extremely sensitive to temperature,and temperature changes will have some irreversible effects on the internal resistance,capacity,and number of charge and discharge cycles and other characteristics of the battery.In severe cases,safety hazards may also occur.Therefore,it is necessary to adopt a thermal management system to maintain the battery temperature range,and it is of great significance to study the battery thermal management system.This paper proposes an indirect liquid cooling scheme based on the heat dissipation target of the ternary lithium ion battery module.The structure design of the parallel channel liquid cooling plate located at the bottom of the module is based on numerical simulation,single factor and orthogonal experimental analysis methods.The heat dissipation effect of the liquid cooling plate under different flow channel structures,the temperature balance ability and the proportion of the system liquid cooling energy consumption are comparatively studied.The main research contents are as follows:(1)A geometric model of the liquid cooling unit is established based on the structure,heat generation and heat dissipation mechanism of the battery,and the heat transfer process of the liquid cooling is analyzed.The average temperature and the average temperature for evaluating the performance of the liquid cooling plate are proposed.The three evaluation indicators of maximum temperature difference and flow resistance pave the way for the next step of analyzing the numerical simulation of the liquid-cooled plate.(2)CFD simulation software is used to carry out steady-state simulation of the liquid cooling plate.Based on the single factor method,the cooling performance of the parallel channel liquid cooling plate under different coolant flow rates,different channel widths and different channel depths is deeply explored.The results show that increasing the coolant flow rate will enhance the heat dissipation performance.When the flow rate is greater than 3.75L/min,the system energy consumption will increase significantly,and the design of the flow channel width on both sides of the narrow middle and the reduction of the flow channel width are beneficial to liquid cooling Board heat dissipation.(3)A three-factor four-level orthogonal test was carried out on the design parameters of the liquid cooling plate,and the sensit ivity of the coolant flow rate,width and depth under the specified evaluation indexes was studied through range analysis,and the primary and secondary design parameters were obtained.The results show that the coolant flow rate has the greatest impact on the heat dissipation performance of the liquid-cooled plate,and also has the greatest impact on the energy consumption.(4)Based on the theory of enhanced heat transfer,it is proposed to add a turbulence structure to the parallel flow channels of the liquid cooling plate,and the performance of the liquid cooling plate under different turbulence structure numbers,different turbulence structure arrangements and different turbulence structure radii is studied.The results show that,compared with the liquid cooling plate without turbulence structure,the maximum temperature drops 9.62 ℃ and the temperature difference drops 11.53 ℃ when the turbulent structure is uniformly distributed.Arranging the turbulence structure is an effective method to improve the heat dissipation and temperature uniformity performance of the liquid cooling plate.(5)The transient temperature field analysis of the liquid cooling unit under 1C fast charging conditions,WLTC conditions and high temperature cooling conditions is carried out to study the influence of the liquid cooling plate on the temperature change of the battery module under the common operating conditions of electric vehicles.The results show that the temperature difference of the battery can be effectively controlled under the action of liquid cooling,but the temperature difference in the height direction of the battery is greater than 5°C in both the 1C fast charging condition and the high temperature cooling condition.