Experiment And Simulation Research Of Silica Cooling Plate Coupled Forced Convection Battery Thermal Management System

With the development of society,people are facing the pressure of environmental pollution,energy conservation and emission reduction.The development of electric vehicles is benefit for the environmental protection.Electric vehicles are powered by the power batteries.And the battery thermal management system can maintain the battery within the appropriate temperature range,ensuring them with the high efficiency,safety and long life.There are many advantages for air-cooling battery thermal management system,such as low cost,simple structure,easy to maintenance and light weight.The silica cooling plates with the high thermal conductivity are used to improve the short coming of air which with low thermal conductivity in traditional air-cooling system.Hence,the silica cooling plate coupled forced convection battery thermal management system was designed and researched in this thesis.In this thesis,the temperature tendency of the battery under 5 C discharged process is tested through the experiment method.Then the temperature curve is fitted through the simulation method with the software MATLAB for the sake of getting the heat generation rate of the battery under the 5 C discharge process,which is about 20.39 W.The silica cooling plate with copper mesh coupling forced convection battery thermal management system is applied in the single battery and tested through the experiment method.The maximum temperature of battery is decrease as the thickness of the silica cooling plate is increasing.Considering the cost and cooling effect,the thickness of 1.5 mm is suitable.The maximum temperature of battery is decrease as the air velocity is increasing.Considering the energy consumption and cooling effect,the air velocity of 3.5 m/s is appropriate.And the experiment also figures out that the position of fan affects little to the heat dissipation,the fan placed in the face side of battery shows slight advantage than placed in the back face.When coupling with two fans,the cooling effect of battery is better than that with one fan.The silica cooling plate with copper mesh coupling with forced air convection thermal management system applied in the single battery is tested through simulation method.The largest relative error between experiment and simulation is within 3%,and the maximum temperature difference between them is within 1.5?,which shows the simulation and the heat generation rate are of high reliability.The structure model of the battery module using silica cooling plate with copper mesh coupling air cooling thermal management system is build and the cooling effect is tested through simulation method.The highest temperature is observed in the battery at the far side of the air inlet.The average temperature of the five batteries using a 1.5 mm silica cooling plate with copper mesh under 5 m/s forced convection with one fan during the 5 C discharge process is 2.87°C higher than that of one battery condition.The average temperature of the five batteries with two fans is 3.59°C higher than that of one battery condition.This is because the accumulation of heat between the junction of the batteries increased as the number of batteries increased.Besides dissipating the heat timely,it is necessary for the battery thermal management system to improve its mechanical strength.Therefore,a silica cooling plate with aluminum cooling plate coupled forced convection battery thermal management system is proposed,and it is applied and tested in the battery module through experiment method.Under 1 C discharge process,the highest temperature of battery module without thermal management system maintains within 41°C,but the maximum temperature difference is more than 3°C,while the one using silica cooling plate battery thermal management system maintain within 1°C.It is because the silica cooling plate with high conductivity is benefit for improving temperature uniformity of the battery module.Under 2 C discharge process,the highest temperature and the maximum temperature difference of battery module that using the silica cooling plate with aluminum cooling plate thermal management system can be maintained in the safe range.But in the higher discharged process situation which is 4 C discharge rate,the thermal management system using the silica cooling plate with aluminum cooling plate need coupling forced convection so the highest temperature and the maximum temperature difference of battery module can be maintained in the safe range.