Numerical Security Assessment In Case Of Fire In Underground Transport Spaces

In case of fire in a subway station and if the fire smoke extraction is not handled properly, passengers may be trapped and thus would be in a life-threatening situation. The most immediate threat is not direct exposure to fire, but the smoke inhalation. The smoke contains hot air and toxic gases. The increasing rate of use of subway stations could lead to an increase in the frequency of serious fires, thus subway station designers and operators must consider all fire aspects, smoke propagation, and ventilation strategies within their facilities. In this paper, heat transfer through the spread of smoke in the event of a fire in a subway station is examined. It concerns the identification of ventilation strategies in the station so as to provide security for passengers and rescuers, based on numerical simulations using the FDS software. Smoke control strategies by traps located at the ceiling associated with different tunnel ventilation were investigated. The results show that the safest strategies are mainly those with air flow rate blown into the station from the tunnels less than the flow rate extracted by the traps. The least safe scenarios are those where the ventilation through the tunnels is accomplished with flow rate greater than the one extracted by the traps.