Smoke diffusion and control at different platform floor structure of subway station in fire

According to the physical model of subway station, three-dimension simulations were done to analyze the smoke diffusion and control system for different typical structures including island-platform and side-platform with or without platform screen door (PSD) in subway station fire which was located in the middle of the train. The characterization of turbulent smoke flow was made up of energy equation, momentum equation, continuity equation, concentration equation and equation of full modified buoyancy, and the SIMPLEC arithmetic was adopted to work out the solutions. The results indicated that when the fire lasted for 360 s on both typical platforms, the smoke diffused on the upper space of the whole platform floor and deposited below 1.8m without PSD. On the contrary, with PSD, the smoke was restrained in the railway tunnel and more smoke was exhausted, all stairs were clean for evacuation. The efficiency of exhausting smoke was raised 15.8% in island-platform and 10.1% in side-platform. The effect of exhausting smoke in the side-platform was stronger than in the island-platform. Compared with the traditional smoke control model, it is found that PSD plays a remarkable role in restricting the diffusion of smoke, which provides a better condition for evacuation in the subway station fires.