Experimental and numerical study on the smoke movement and smoke control strategy in a hub station fire

Smoke movement is more complex in a station fire hub than in a common situation, and it is also difficult to deal with. In this paper, full-scale experiments were conducted to investigate the ceiling temperature, smoke-layer thickness and the temperature distribution within the station. The effect of smoke exhaust system and the velocity at staircase on smoke flow were investigated when the fire source located near the staircase, using a series of FDS numerical simulation. From the full-scale experiment and simulation results, several conclusions were made: (1) The full-scale experiment results showed that the sprinkler system was capable of confining the temperature rise if it is activated; (2) Meanwhile, it also proved that the propagation of smoke could be effectively controlled when the mechanical smoke exhaust system is switched on; (3) Based on the simulation results, smoke spread rapidly in the platform floor at the early stage and then it entered into the staircase when the smoke exhaust system was absent; (4) Even though the exhaust and supply system opened, smoke could still propagate through the staircase if there's no downward airflow at the entrance; (5) When the downward airflow existed, smoke still cannot be effectively discharged without the smoke exhaust system.