| Power battery as the power source of the pure electric vehicles,Its advantages and disadvantages directly determine the performance of the vehicle.Lithium ion battery has high energy density and long cycle life,is the new energy vehicles,especially the ideal power supply temperature of the pure electric vehicles produced important influence on the performance of battery life and work,the highest temperature and the temperature uniformity is affect battery life and performance of the two most important factors in this paper,a company production of ternary lithium ion battery as the research object,by using the combined method of theoretical analysis and numerical simulation module and from the Angle of the thermal battery monomer battery pack,etc,the research and design The main research contents are as follows:(1)Analysis of the lithium ion battery structure,heat production and heat transfer principle,the heat production rate by Bernardi battery model to calculate the heating rate of monomer battery,battery monomer are calculated by using STAR-CCM+ software analysis in different discharge ratio in different environmental temperature convection heat transfer coefficient and the temperature rise under different initial battery temperature characteristics.(2)On the basis of heat transfer and CFD theory,established the battery module,cooling analysis and calculation model of dynamic heat transfer characteristics of the selected three kinds of cooling plate structure,this paper carried out simulation on three kinds of cooling plate compared to select the better cooling plate heat dissipation performance of the selected cooling plate.(3)Orthogonal experiment design,respectively,selected the coolant inlet velocity of coolant temperature pipe rotation frequency and channel width for experimental design factors,constructs the four factors,four levels orthogonal test table,each parameter was analyzed by STAR-CCM+ software calculation for battery module,the influence of cooling performance.(4)Using the particle swarm multiple objective optimization algorithm,with coolant inlet flow rate and temperature is variable,according to the maximum temperature difference in temperature of the battery module and the power consumption of the cooling system has carried on the multi-objective optimization,the optimized model there is a more balanced between the heat dissipation performance and power consumption.(5)The cooling structure model of the battery pack was established,and the temperature rise characteristics of the battery pack under 3C discharge rate were simulated in STAR-CCM+ software.CRUISE software was used to build the vehicle model and simulate the FTP75 cycle condition to obtain the dynamic current of the vehicle under this condition,and the transient simulation of the battery pack liquid cooling system under the actual condition was carried out.Design of battery pack cooling system control strategy,when the temperature of the battery pack is lower case closed cooling system,when the rising of the temperature of the battery pack,open branch,radiator coolant through the radiator cooling,when the temperature of the battery pack is higher,the radiator cooling capacity is insufficient,close the radiator to open refrigeration unit branch,cooling liquid by cooling refrigeration unit. |
