| At present,the problems of energy and environment are attracting much attention,so the electric vehicle has also attracted extensive attention and research.As the "heart" of electric vehicle,power battery is the key part of electric vehicle.It plays a vital role in electric vehicle and affects the performance of electric vehicle.Lithium-ion batteries have the advantages of high specific energy and long life,etc.,which are widely used in power batteries,and have gradually become an ideal power source for electric vehicles.Temperature has different degrees of influence on the performance of lithiumion batteries,high temperature and temperature inhomogeneity can affect the safety and performance of batteries,so in order to ensure the performance and safety of batteries,the use of battery thermal management system is very necessary.First of all,this paper analyzes the characteristics of lithium ion power battery,such as lithium ion battery classification,composition,working principle and heat generation,heat transfer principle,followed by the battery to do a characteristic test,that is,the impact of temperature at different rates on charge and discharge performance.In order to verify the accuracy and do the simulation analysis of lithium battery,the simulation software of ANSYS,including the determination of single cells to produce heat and heat capacity,as well as to the establishment and validation of monomer battery simulation model,build a model used for CFD software,for the rest of the lithium ion battery surface plate heat dissipation design and performance analysis provides the basis.Secondly,the model test and simulation analysis of the liquid-cooled plate were studied.On the basis of constructing the liquid-cooled plate CFD model and satisfying the energy conservation equation,the liquid-cooled plate was processed.The heat dissipation performance of the liquid-cooled plate was simulated and analyzed,and the verification result error was less than 5% through experimental comparison.It is shown that the simulation method can effectively reflect the heat dissipation performance of the liquid cooling plate of the single cell.In the following optimization design,the method of simulation is used.Then,the lithium ion battery surface plate heat dissipation design and performance analysis are studied,including monomer structure and import and export mode,the shape of the surface plate surface plate in the middle channel are connected,the channel of import and export quantity,width,height and the number of import and export,the highest temperature contrast the simulation results,the pressure drop,average temperature,The comprehensive evaluation index PEC is optimized layer by layer,and a better working condition is selected as the basic template to study the heat dissipation performance of the battery pack in the future.Finally,the heat dissipation performance of liquid-cooled battery pack module is analyzed and studied,including the establishment of battery pack model and grid division,namely CFD numerical analysis.Next,it is imported into ANSYS simulation software,and the simulation is carried out on the premise of setting boundary conditions and initial conditions.In the simulation analysis of the battery pack,3C and 5C discharge rates are selected to compare to ensure that the analysis results are more comprehensive and accurate.Then,the influences of different mass flow rates,different quantities of liquid cooling plates and different inlet and outlet directions of the channel on the heat dissipation performance of the battery pack are analyzed.The results show that 1.5g/s mass flow rate has better heat dissipation performance and lower power consumption.Under the premise of permissible manufacturing cost,the use of five liquid cooling plate can make the battery pack heat dissipation performance in the optimal state;The different inlet and outlet directions of the channel have certain influence on the maximum and average temperature of the battery pack. |
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