Study On Heating Characteristics Of Al-Si Alloy Phase Change Energy Storage Heating Device For Electric Vehicles

Electric vehicles have the advantage of saving energy and producing zero emissions.However,in cold climates,a part of battery energy of the electric vehicles is used to provide the heat needed to heat the cabin,which can lead to a significant reduction in mileage.In order to solve this problem,this thesis proposes a compact phase change energy storage system based on Al-Si alloy for electric vehicle heating,and carries out experimental research on its heat storage,heating and heating intensification.The research results have a good reference significance for improving the problem of electric vehicle range shortening caused by heating in winter.The main contents of this thesis include:1)The production of experimental prototype of Al-Si alloy phase change energy storage heating device and the construction of the test system;2)Analysis of heat storage and heating performance of experimental prototype of Al-Si alloy phase change energy storage heating device;3)The heating enhancement of Al-Si alloy phase change energy storage heating device.The results are as follows:（1）The volume,weight and heat storage of the experimental prototype of Al-Si alloy phase change energy storage heating device are 40.2 L,37 kg and 7.34±0.1 k Wh,respectively.The heat storage density is 181.84Wh/L,and the heat storage density is 198.37 Wh/kg.The unit’s heat storage density increased by 10.2%per unit weight compared to power battery heating.（2）The experimental prototype of Al-Si alloy phase change energy storage heating device can realize the heating power of 360～2350 W in a heating cycle,with the average heating power of 1317 W,the total heating capacity of 5.7 k Wh and the heating efficiency of 75.89%.（3）Fin,foamy copper and copper tube are used to strengthen the heating process,in which foamy copper has the best heat transfer enhancement effect.The mass of foamy copper is only 39.5 g,and the average heat transfer coefficient and average heating power are 18.3%and 15.9%higher than that of bare tube heat transfer,respectively.（4）With foamy copper as the filling material for intensified heating,air flow rate,valve opening and outlet air temperature are set respectively,and the heating characteristics of Al-Si alloy phase change energy storage heating device under six different combinations are obtained:1)When the valve opening is 30%and the air flow rate is 80 m~3/h,the average heating power,heating time,heating capacity and the maximum outlet air temperature are1239W,6.5 h,5.60 k Wh and 115℃,respectively;2)When the valve opening is 30%and 100m~3/h,the above parameters are 1497 W,5.7 h,5.69 k Wh and 122℃,respectively;3)When air flow rate is 80 m~3/h and outlet air temperature is 70℃,the average heating power,heating time,heating capacity and valve opening are 890 W,7.4 h,5.23 k Wh and 0～49%,respectively;4)When the air flow rate is 80 m~3/h and the outlet air temperature is 90℃,the above parameters are 1270 W,6.2 h,5.50 k Wh and 0～34%,respectively;5)When the air flow rate is 100 m~3/h and the outlet air temperature is 70℃,the above parameters are 1161 W,6.1 h,5.50 k Wh and 0～47%,respectively;6)When the air flow rate is 100 m~3/h and the outlet air temperature is 90℃,the above parameters are 1584 W,5.3 h,5.61 k Wh and 0～32%,respectively.