Research On Questions Of The Fresh Air Amount Inside The Subway Car And Subway Station

This paper was written to mainly research on problems of fresh air amount inside the subway car and subway station, because the air quality of the subway car and subway station which were in the underground space, depend on supply of the fresh air whether enough or not, and the especial piston effect in running of the subway car impacted obtaining of fresh air amount inside subway car when the subway car in different positions along the metro lines. First of all, from the aerodynamic theory formula, analyzed piston effect caused by train when traveling in the singlet tunnel with ventilation shaft. In order to more fully study the piston wind effect on the air quality of subway metro tunnel, carriages and station, In this paper, firstly an island-style subway station was studied as a object, selected3different conditions include the pitted side separately setting ventilation shaft, the outbound side separately setting ventilation shaft, the pitted side and the outbound side both setting ventilation shafts. Fluent was used to establish the two-dimensional model of metro tunnel and train, analyzed the piston effect on tunnel airflow in the whole running process include subway train in the deceleration stopping, stopping, and speeding up the off-site. And in the case of without considering the station air-conditioning system, the piston wind effect when train stopped and tunnel ventilation system were used as the basic way of station ventilation. Airpak was used to establish the model of a3D island-style subway station, analyzed the piston wind effect on airflow of subway platform when platform screen doors fully opened during the single train or double train stopping stage, And studied whether the introduction amount of outdoor fresh air satisfied the requirement of specification, on fresh air amount of passengers in subway cars and station, on fresh air amount of diluting CO2, and on minimum ventilation frequency. Obtained the programs of setting ventilation shafts both on pitted side and outbound side was best for the demand, to keep the subway environmental air quality good. Also through simulating the air age of subway station, this paper analyzed the level of fresh air of different positions in subway platform more comprehensively.