Design And Optimization Of Heat Dissipation Structure Of Power Battery Based On Microchannel Liquid Cooling Plate

In the 21st century,under the double pressure of environmental pollution and energy shortage,governments and major automobile manufacturers around the world have increased their research and development efforts on electric vehicles.As one of the three major components of electric vehicles(battery,motor,electronic control),power battery has also been widely concerned by governments and major automobile manufacturers.At present,lithium ion battery is considered as a suitable power source for electric vehicles,which has been studied by scholars.When people pursue high density,it also brings the problem of high heat,and high heat will cause a sharp rise in temperature,which brings great challenges to the performance of lithium batteries and the safety of electric vehicles.In this paper,the heat dissipation structure of power battery is designed and optimized based on microchannel liquid cooling plate.The main research contents are as follows:(1)Prepare experimental equipment and build an experimental bench for single batteries.Under three environmental temperatures,the heat generation of single battery under different charge and discharge rates is studied.Through different experimental groups,the detailed data of cell surface temperature changes are obtained,and combined with the related formulas of cell heat generation calculation in previous literature,the specific heat generation value of cell during discharge is calculated.(2)The thermal model of single cell is established,and the array thermal simulation is carried out after the grid quality reaches the standard.Finally,the simulation results are compared with the experimental results,so as to verify the reliability of the thermal simulation of the single cell and ensure the accuracy of the following research contents.(3)The microchannel cold plate in liquid cooling experiment was processed and assembled,and then its precision and sealing performance were measured.Then,a whole set of liquid cooling experiment bench is built,and then its reliability is verified.Finally,three groups of liquid cooling experiments are carried out and their specific data are sorted out.(4)Based on the traditional liquid-cooled plate with microchannel structure,a new liquid-cooled plate with microchannel structure is proposed.At the same time,a threedimensional fluid-structure coupling model is established.Combined with CFD numerical simulation and experimental research,the error between experimental data and simulation results is less than 5%,which verifies the reliability of simulation.Then,the influences of the number and width of channels,the number and width of outlets and the number of rows of fins on the temperature characteristics of liquid cooling plate and the power loss of pump are analyzed.Then,through orthogonal experiment,five variables were synthesized,and the microchannel cold plate with better structure was preliminarily selected.Finally,combined with the multi-objective optimization genetic algorithm,the structure of microchannel liquid-cooled plate is further optimized,so as to obtain the microchannel liquid-cooled plate structure with better heat dissipation performance.At the same time,it also lays a foundation for the selection of microchannel cold plate in battery pack heat dissipation.(5)Combined with the optimized micro-channel liquid-cooled plate structure above,Under the four discharge rates,the influence of the temperature of the cooling liquid and the arrangement of the microchannel cold plate on the temperature field of the battery pack is analyzed.