| In recent years,under the background of“double carbon”,electrochemical energy storage technology has been developed rapidly.Lithium-ion battery plays a leading role in current electrochemical energy storage system because of its high energy density,long service life and low self-discharge rate.The operation process of electrochemical energy storage system is accompanied by the charging and discharging behavior of lithium battery.The internal electrochemical reaction will generate a large amount of heat and lead to the temperature rise of the battery,which will adversely affect the performance and life of the battery,and even lead to thermal runaway in serious cases,threatening the safety of the electrochemical energy storage system.Therefore,it is crucial to design a reasonable and efficient battery thermal management system.At present,there are few researches on the thermal management of battery cabinet.In this paper,a model of the air-cooling heat dissipation system of battery cabinet was established,and the air-cooling heat dissipation performance of battery cabinet was studied through CFD simulation,and the influence of different factors on the heat dissipation performance was analyzed.The main research contents of this paper are as follows:（1）The working principle and heat generation mechanism of lithium ion battery are summarized,and the thermal model of lithium ion battery is established.The battery discharge experiment was carried out,and compared with the simulation results,the maximum absolute error was only 1.7℃,which verified the validity of the battery thermal model.The temperature distribution of the battery under different discharge rates was simulated.（2）A single-layer battery cabinet,that is,the air-cooled heat dissipation CFD model of the battery pack,was established,and the effects of different discharge rates,inlet flow,battery gap,inlet position and size,and the distance between the battery pack and the battery cabinet wall on the heat dissipation performance of the battery pack were studied.The critical inlet flow rate for discharge rate,battery gap and inlet temperature under different operating conditions is given.The results show that the maximum temperature and the maximum temperature difference of battery pack can be effectively reduced by increasing the inlet flow rate and the battery gap and decreasing the distance between battery pack and cabinet wall.The inlet flow rate has the greatest influence on heat dissipation.When the inlet flow rate is 0.2m~3/s,the maximum temperature and maximum temperature difference of the battery pack drop to 35.4℃and 6.9℃.However,the increase of inlet flow will lead to the increase of fan power consumption;increasing the battery gap and the distance between the battery pack and the cabinet wall will reduce the volumetric energy density of the battery cabinet.（3）Simulation analysis was carried out on the air-cooling heat dissipation of the multi-layer battery cabinet,and the air-cooling heat dissipation experiment of the battery cabinet was established to verify the accuracy of the CFD simulation method of the air-cooling of the battery cabinet.The effects of different air supply modes,inlet flow rate,the number of batteries in each layer and the number of battery cabinet layers on heat dissipation performance were simulated.The results show that the independent air supply of each layer has the best heat dissipation performance,and the top air supply and bottom air supply have little effect on heat dissipation.With the increase of inlet flow rate,the maximum temperature and average temperature of battery cabinet decrease,but the temperature uniformity becomes worse.Increasing the number of batteries in each layer and the number of battery cabinets has little effect on heat dissipation performance,but can effectively increase the volume energy density.When the number of batteries in each layer increases from 6 to 9,and the number of battery cabinets increases from 2 to 6,the maximum temperature and maximum temperature difference fluctuate within 2°C. |
PDF Full Text Request