Research On Synergetic Analysis Of Thermal Flow Field Of DC Charging Pile

As the size of the world economy and the number of people continue to grow,the competition for energy in the world is intensifying.The development of new energy sources and the development of clean,environmental protection and energy conservation are urgent.Under this development trend,various new energy vehicles are born in the needs of the times,among which electric vehicles are the mainstay.As the most important device for electric vehicle charging facilities,charging piles provide power supplement for electric vehicles.Vigorously developing electric vehicles and their charging facilities has become a problem that cannot be ignored in global energy development.With the continuous development of the power level of DC charging piles,the power density of the internal high-frequency switching rectification power module is also increasing.How to choose a reasonable cooling method to reduce the overall temperature rise of the charging pile and ensure the reliability of the charging pile? It can directly affect the promotion and application of electric vehicles.In this paper,150 kW DC charging pile is taken as the research object.Simulation software is used to simulate and analyze the internal fluid field and temperature field,and the internal heat transfer of DC charging pile and power module is analyzed.Firstly,this paper takes the 15 kW power module inside the DC charging pile as the simulation object,theoretically analyzes the thermal simulation model of the power module according to the theory of heat transfer and fluid mechanics,selects the best cooling method according to the calculation result,and determines the ventilation of the power module.The model of the quantity and cooling fan.Secondly,the structural parameters(including fin thickness,number of fins and fin height)of the finned heat sink inside the power module were optimized by orthogonal test method.The orthogonal test method is used to process the orthogonal test results to find the primary and secondary order and influence trend of the three factors affecting the heat dissipation effect of the power module.The variance analysis method is used to calculate the weight of the influencing factors of the heat dissipation effect of the power module.The combination of the two determines the optimal structural parameters of the heat sink.The optimized heat sink is applied to the power module model and simulated.The variation of the fluid field and temperature field of the power module before and after optimization is compared.The variation law is analyzed by field synergy theory to verify the fluid of the optimized model.The field and temperature field have better field synergy and lower temperature rise.Finally,the optimized power module is applied to the overall simulation of the DC charging pile,the boundary conditions and the solution parameters are reset,and the field and the temperature field cloud map of the charging pile before and after the power module optimization are analyzed.The field synergy effect of the model verifies that the field synergy of the optimized model is better than the original model.The reasonable power module structure can not only meet the temperature rise requirement of the power module,but also reduce the overall temperature rise of the charging pile,and achieve the purpose of improving the reliability of the charging pile operation and energy saving and emission reduction.The improved model has a flatter and evener distribution of the internal fluid field and temperature field,and the field synergy is better,thus achieving the purpose of reducing the temperature rise.This provides a theoretical basis for the subsequent heat dissipation design of high-power DC charging piles and related products.