Calcalation The Heat Transfer Coefficient Of Light Urban Rail Trains In Cold Regions

With the continuous development of national economy,the size of the city increasing,and the subway construction extends to high latitudes and colder regions.At the same time,how to reduce the heat transfer caused by the subway inside and outside environment temperature increase.Air conditioning energy is a large part of the subway train operation energy,especially running in high latitude and cold regions subway trains.How to accurate get the subway heat transfer characteristics,and then put forward the optimization of targeted heat preservation and heat insulation,,is the key to reduce the subway air-conditioning energy consumption.So this article,which is based on subject of higher and colder subway heat insulation performance research,by adopting the combination of experiment and numerical calculation method,study the subway heat transfer characteristics and heat preservation performance.The main research content as follows:Based on steady state heat transfer of multiply layers falt wall.analyzed the heat transfer characteristics of subway in high altitude and cold regions,and the three kinds of typical structure steady heat transfer experiment was carried out.The numerical calculation model of heat transfer of train body was established.Through contrast experiment and numerical calculation results,verified the accuracy of numerical model and algorithm provides a theoretical basis and experimental research method for this article.The relationship between aluminum extruded sections thermal conductivity of the floor,the side wall and the roof and the number of fins,the thickness of the fins and the inclination angle of the fins were studied by numerical calculation.The mathematical relationship between the thermal conductivity and the influence parameters of the three typical structural profiles is obtained,then the thermal conductivity of the aluminum extruded sections can be calculated quickly and accurately,which provides the basis for the study of heat transfer of subway passenger room vehicle.Aiming at the hor bridge problem caused by the fixed bolts in body of high altitude and cold regions subway,Select four kinds structure as the typical heat transfer on structure bridge,is the floor rubber washer,seat fixing structure,seat back bolt and roof bolt.Obtained different thermal heat flow and thermal heating flow of subway,after comparison the increase heat flux of the typical structure of inner and outer surface.The results provide the basis for accurate K value of heat transfer coefficient.Finally,according to the results of second and third part in this paper,according to the physical size of the 1:1 and use the Gambit to establish the 1/4 subway passenger compartment steady heat transfer model.After independence in the full study of the grid computing model,through the calculation of subway heat transfer coefficient K value and the thermal correction factor is obtained.The heat transfer characteristics of subway room on the basis of a comprehensive analysis,while the introduction of heat transfer weight per unit area ratio and the typical structure heat transfer capacity be evaluate.According to the analysis results,put forward the optimization scheme for thermal insulation of the insulation weak structure in subway passenger rooms.