Thermal Field Analysis And Optimization Design Of Electric Heater For Rail Transit Vehicle

The design of rail vehicle electric heaters is not only the design of structural materials,but also the theory of aerodynamics and heat transfer.Due to technical limitations and lack of cost investment,few companies will conduct research on basic principles,let alone investing time to study the effects of various structural materials and other parameters on the performance of electric heaters.Most still rely on experience accumulation.When designing the solution,it is necessary to produce a prototype to verify that the design is feasible,and then modify the design according to the data obtained from the test.Mature products have empirical data to draw on,but in the development of new products,this design of the product is somewhat blind,often takes a lot of time and materials to test.Often,the product design and experiment process requires multiple iterations to meet design expectations,resulting in an extension of the product development cycle and an increase in cost.Combining the basic theories of computational fluid dynamics and heat transfer can improve the accuracy of analyzing the temperature and distribution of products at various points.These theories are too comprehensive,and general product design engineers do not have such analytical capabilities.In view of this situation,it is necessary to carry out research on the electric heaters of rail transit vehicles by using computer software that has easy-to-operate analysis functions as analysis tools and numerical calculation methods.By analyzing the thermal field of the electric heater,the influence of heat transfer factors of the electric heater on its temperature is explored,and the analytical model is optimized.The study is as follows:(1)According to the current structure and working principle of electric heaters for rail transit vehicles,the internal heat transfer methods are analyzed,and the analytical calculation methods for commonly used heat transfer modes are compiled,and numerical calculation methods are used for the heat transfer process of electric heaters.Applied research.(2)Establish a thermal field analysis and calculation model for natural convection electric heaters.Through simulation calculations,obtain the temperature values of the shell and the heating element,and compare them with the experimental data to verify the feasibility of the simulation calculation.(3)Establish the thermal field analysis and calculation model of the forced convection electric heater.Under the constant air volume,calculate the temperature values of the outer casing and the electric heating element,and verify the feasibility of the simulation calculation method by comparing with the experimental data.(4)Using heat transfer theory to analyze and analyze the factors affecting the heat transfer of electric heaters,especially the factors affecting the heat transfer and changing the temperature of the shell or heating element.Put forward the direction of improving the program.(5)According to the current design requirements of electric heaters for rail vehicles,the influence of power on the temperature of electric heaters is studied for natural convection plate type electric heaters and forced convection plate type electric heaters,and an optimized design method is proposed.This provides designers with some ideas for the design of electric heaters,and determines the direction of follow-up research.