A Study on Heat and Smoke Exhaust Characteristics from the Subway Fire for Different Ventilation Modes

This study is focused on the numerical predictions for different smoke-control ventilation modes for the subway fire. Smoke-control ventilation mode in the domestic platform is that exhausting for the smoke detected zones while supplying air or stopping any ventilation for other zones in the platform. Three cases of smoke control ventilation modes are considered. First and second case are present running smoke control mode in Korea. The third is that smoke-control ventilation fans equipped in the platform are operated in first 4 minute(platform evacuation time, NFPA130) since then the fans equipped in the platform are stopped and the fans equipped in the tunnels are operated. Distributions of heat, carbon monoxide and visible range are compared at a height of 1.7m(passenger breath/sight height) above the platform. The numerical results show that air supply fan operation in the platform causes the smoke disturbance and a rapid spread of the smoke. The switch-operation with fans in both the platform and tunnel are better than operation with only platform fans in smoke rejection efficiency.