Research On Thermal Management System Of All-weather Battery Pack For Pure Electric Vehicle

Sales volume of electric vehicles is far lower than that of traditional gasoline vehicles.One of the main constraints is environmental adaptability.At present,electric vehicles do not have the same environmental adaptability as traditional vehicles,In the extreme environment of high temperature and high cold,the battery will fail to work normally.Environmental adaptability has become an important problem in the electric vehicle industry for a long time.This paper will discuss a new battery thermal management scheme,which can make the battery work normally in various extreme environments.Based on the assumption that the theory of battery thermal management is contrary to the existing theory,the strategy of battery thermal management in full thermal enclosed environment-total thermal management strategy is put forward for the first time.Based on this theory,the battery developed is called "all-weather battery pack".The total heat management system first isolates the batteries inside the battery pack from the external heat exchange completely.The batteries inside the battery pack does not directly exchange natural heat with the external environment,but only conducts controllable heat exchange with the efficient heat management system inside the battery pack.The model of battery thermal management system is built according to the total thermal management strategy,and the performance of battery pack in extreme hot and cold environment is simulated by using the CFD analysis software(Star CCM +).The multi condition simulation test is carried out for the use effect of battery pack in the whole vehicle : Static insulation in extremely cold environment,Vehicle operation in extremely cold and hot environment,The latest global uniform light vehicle emission test cycle working condition method is adopted for the whole vehicle operation.In order to verify the improvement of adaptability of all-weather battery compared with traditional battery environment,The comparison and simulation analysis of 12 hours Standing in-35 ℃ extreme cold environment,one hour WLTC in-35 ℃ extreme cold environment and two hours WLTC in 55 ℃ extreme hot environment were carried out,The comparison of data shows that the all-weather battery pack developed by the all thermal management strategy has four times the insulation capacity of the traditional battery pack in extremely cold environment,After wltc operation in extremely cold and hot environment,The temperature uniformity of cells in the battery pack is much higher than that in the traditional battery pack,and the ideal working temperature can be maintained,Weatherability of vehicle is close to the level of the traditional gasoline vehicle.The use of pure electric vehicles is no longer restricted by extreme climate.