Numerical Simulation Research Of The Air Quality In Subway Train

The subway is an extraordinarily brilliant solution that solves the congestion of cities traffic problem and promotes the efficiency of cities transport.For the past few years,it is developing rapidly,meanwhile the subway was constructed and applied in every city and everywhere.Excepting the safety,high-efficiency,speed,energy conservation and environment-friendly advantages,metro still has plenty of defects,such as ventilation shortcomings that passengers may feel a little bit hotter or cooler when they take the subway.Well air distribution is the fundamental condition of passenger's comfortableness.Well,researching the distribution of temperature field and airflow features in the tunnel and the inside of vehicles is a vital proposition that cannot be neglected.This paper introduces the current situation of the metro environment,the domestic and international research on the subway and tunnel airflow distribution,the development of computational fluid dynamics and the working mechanism of the Peking B-type subway air supply system at first.Then,in following section,the Peking B-type subway and a length which is between one metro station to another is used as the research object.Meanwhile,in next segment,the model of subway and tunnel are established by using sketchup software,and then the model is leaded into CFD(Computational Fluid Dynamics)simulation software.Furthermore,the model is divided into grid by CFD simulation softer,and then the CFD simulation software numerically simulates the model.Finally,through analyzes the conclusion of those procedures above,draws the proposal.This paper analyzes the factors that affect the airflow distribution in the metro compartment.First,via we change the arrangement of the air inlet and return air outlet of the subway train,and discuss the airflow distribution in the static subway vehicle,the optimal arrangement may will be given.Then,we obtain the rule of the airflow distribution in vehicle inside when the no-load subway is running in the tunnel by means of research with the airflow distribution and influence of tunnel environment to vehicle inside airflow distribution.We cloud draw the conclusion that following metro speed going fast,tunnel circumstance will influence the temperature field and the velocity field that subway inside more effectively.Finally,to close to the real circumstance brings the human body model into the simulation software,and calculates when the passenger(human body model)turns into vehicle.What the law of airflow distribution that inside vehicle is drawn from analysis the situation above.After human body model was added,both side of edge will low down the temperature first,meanwhill owe to the sluggish circulation in middle of the subway,it would be hotter than edge sides of metro itself.Based on the probe of the problem,the paper puts forward to meet the subway compartment airflow distribution and passenger comfort of the program and recommendations.The research of this paper has a certain practical value for optimizing the arrangement of airflow in the subway station and the way of air inlet and air outlet.