The Optimization Design And Simulation Of Heat Exchanger On Air Conditioning Of Rail Transport

The railroad refrigerating and air conditioning system is different from domestic and commercial air conditioners.In order to save the installation space,it is generally composed of unit overheads,including compressors,heat exchangers,throttling devices,etc.Each unit is installed in a box.To form a complete air conditioning unit.The heat exchanger plays an important role in transferring heat.Its working efficiency determines the cooling capacity of the whole machine,and its volume accounts for about 30%-40%of the entire machine volume,which plays a key role in the compactness of the entire machine.Therefore,the advantages and disadvantages of structural parameters design of the heat exchanger will directly affect the volume of the air conditioning unit and the overall work efficiency.Because the traditional theoretical research and optimization design methods are only optimized with a single objective,the reliability and universality of the heat exchanger optimization design results are difficult to guarantee.Therefore,based on the theoretical basis of computational fluid dynamics and heat transfer,multi-objective optimization analysis is performed on the structural parameters of flat finned heat exchangers.Finally,a set of optimal parameter combinations is selected to optimize the design of the heat exchanger.Research provides reference.In this paper,a rail transit air-conditioning heat exchanger was designed as the research object.First of all,in accordance with the needs of the heat exchange capacity of the railcar,considering the operating environment of the rail transit air conditioning,the overall structure design of the heat exchanger was performed,and the fin structure was selected.Type and optimal design.The Ansys DM module was used for parametric modeling.The calculation cost was considered and the model was simplified.The ICEM was used to structure the model and the fluid was used to calculate the fin structure of the heat exchanger using the fluid calculation software Fluent.Then,four optimization parameters were selected:fin pitch,heat pipe diameter,lateral center distance of heat pipe,and vertical center distance of heat pipe,to study the effects of heat transfer factor,resistance factor and heat exchanger volume.Matlab was used to fit the quadratic polynomials to the three targets.The non-inferiorly-ordered genetic algorithm(NSGA-?)was used to optimize the three objective functions.Finally,a set of structures that were more suitable for the fins of rail transit air-conditioning heat exchangers was obtained.Parameter combination.The research results show that the optimization of the heat exchanger structural parameters program is verified in the Fluent software.The results show that the optimized design scheme improves the heat exchange efficiency of the heat exchanger,the resistance of the axial fan,and the heat exchanger.The volume is reduced to achieve the desired optimization effect.