Analysis and Optimization of Ventilation Mode of Smoke Control System in Subway Station Fires

In the subway station fires, the most immediate threat to passengers’ life is not the direct exposure to fire, but the smoke inhalation because it contains hot air and toxic gases. Theoretical analysis and CFD simulations are applied to analyze the various possible ventilation model and obtain the optimization of ventilation mode in the subway station fires. According to the structure characters of the subway station and the mechanics analysis of smoke flowing, the air curtain is put forward to control the smoke diffusion according to the streamline and flux principle. The computational mathematical model of the air curtain is derived theoretically. The results indicate that more than 6 minutes for safe evacuation can be guaranteed by air curtain. The quantity of fresh air that the air curtain needs has been only 2/5 of which the traditional method, which effectively prevent the fire expand and control the smoke diffusion.