CFD Calculation And Analysis Of Electric Cabinet Ventilation System Of Hybrid Locomotive

With the rapid development of Chinese economy,the products developed by using hybrid technology meet the requirements of national policies and industrial development,and the research and application of new hybrid locomotives meet the national medium and long-term development strategic plan.The equipment carried in the electric cabinet of hybrid locomotive is mostly high-power and high-power electrical equipment,and the assembly structure is complex.High power consumption electrical equipment will generate a lot of heat during operation.In order to make the temperature rise of electrical equipment components not exceed the limit and ensure the operation reliability and safety of the electrical cabinet,forced air cooling is usually used to ventilate and dissipate heat in the electrical cabinet.In this paper,the ventilation system of electric cabinet of hybrid electric locomotive is calculated and analyzed by CFD.The three-dimensional modeling software Creo is used to model,measure and analyze the frame structure and component layout in the electric cabinet.Under the platform of ANSYS Workbench,the calculation model is calculated and post processed through Fluent and CFD-Post.By analyzing the basic parameters such as temperature,speed and pressure of the calculation results of the initial scheme,two improvement schemes are proposed and calculated and analyzed,and the basic parameters and flow performance of different schemes are compared.The final improvement scheme effectively reduces the temperature of components in the electrical cabinet and has better flow performance,so that the electrical cabinet has good ventilation and heat dissipation performance,and ensures the safety and reliability of the operation of the electrical cabinet.Aiming at the large space flow field of the magnetic device module of the electrical cabinet,taking the initial scheme and the improved scheme(II)as the analysis object,the sections of the densely arranged LLC module transformer and the main inductance of the three-level module are created.The synergy between velocity field and temperature field,velocity field and pressure field is analyzed.After comprehensive comparison,it is found that the two synergies in the improved scheme(II)are better,the heat dissipation effect is better,and the work efficiency of pressure is higher as a whole.Aiming at the fin radiator in the fixed cooling air duct of the electrical cabinet,the size of the fin radiator is optimized based on genetic algorithm,and the thermal resistance expression is obtained through the thermal resistance network model.Taking the lowest total thermal resistance of the radiator as the optimization goal and the fin thickness W_p and fin spacing W_cis the optimization variable,the optimization mathematical model is established,and the fin thickness is calculated when W_p is 3.5 mm,when fin spacing W_c is 2.5 mm,the total thermal resistance of the radiator is the lowest and the heat dissipation effect is the best.The simulation results show that the optimization result is reliable.At the same time,through the control variables,the laws of velocity,pressure and turbulence performance of fin radiator air duct with different fin spacing and different fin thickness are analyzed.