Numerical study on the optimization of smoke ventilation mode at the conjunction area between tunnel track and platform in emergency of a train fire at subway station

Abstract

To cope with fires in a subway station, ventilation systems are usually installed, which includes an air supply system and a smoke exhaust system. In case of a train fire, the operation of these ventilation systems needs to be studied in order to get optimal control of smoke propagation and provide better environmental conditions for personnel evacuation. In this paper, CFD simulations are carried out by Fire Dynamics Simulator (FDS) to study the effectiveness of different ventilation modes in case of a train fire in a subway station. The temperature and visibility contours are computed as to compare the performance of various ventilation modes for subway stations with full-seal Platform Screen Door (PSD) or half-height safety door. Results show that appropriate activation of the air supply system can improve the efficiency of the ventilation system in smoke control, and vice versa. It is better to activate the lobby air supply system and meanwhile close the platform air supply system. As for the exhaust system, it is necessary to activate the platform exhaust system and the Over Track Exhaust (OTE) system, and it is better to deactivate the Under Platform Exhaust (UPE) system. The optimization strategy of the ventilation mode for subway stations with full-seal PSD is similar to that for subway stations with half-height safety door. With the help of the additional smoke barrier, smoke propagation in a subway station can be well controlled. The results in the paper may serve as a useful reference for the smoke control design in case of subway train fires.