Study On Numerical Simulation Of The Subway Station Ventilation System Under Fire

In 21^th century subway is the main vehicle in the city. When subway supplies people with much convenience, it also brings much damage.If the subway has a fire, it will bring enormous harm to people's lives and property because of its own character. So it is necessary to know as many things in subway fire as possible so as to design safer mechanical ventilation system under fire. To know some important things about the subway fire, I simulate a fire in the platform and the tunnel in the Xisanqi subway station with FDS, and summarize the result in several aspects. I hope what I have done will do mechanical ventilation system under fire some good.After simulation I find that the effect of opening partial screen doors near the fire to exhaust smoke is better than that of opening all screen doors during a fire in the platform. It can exhaust smoke faster,reduce the area of smoke and high temperature, decrease the maximum temperature, offer a better visibility and worth its salt in super fire. Opening partial screen doors system is better than opening all the screen doors system, and it can come true easily. First,it need no more equipment . Second, opening partial screen doors instead of opening all the screen doors in the mechanical ventilation system will be ok. In order to guarantee the safety of people's lives and property better, I hope desingers will apply the mechanical ventilation system of opening partial screen doors in platform screen doors system subway station.Except the above discovery I also find that the style of stairs, the size of the opening of the two sides of the stairs in the platform and a fire plume can affect the movement of the airflow a lot in the platform. So I hope designers of ventilation system under fire can consider their impact on the movement of the airflow fully. The whirl tube above the orbit and below the platform should adopt variable cross section tube,which poises the volume through every ventilator,and it will be good for the subway station both in order and under fire. During a train fire in the tunnel in the station it is necessary to close partial screen doors to control the fire and the smoke better after that all the passengers get out of the trains.