Full-scale experimental study on fire-induced smoke movement and control in an underground double-island subway station

Abstract The research carried out full-scale fire experiments for smoke movement and control in an underground double-island subway station. Four kinds of fire scenarios were designed in the station hall and platform respectively, and series of thermocouples were arranged in the public space. Several vital fire parameters were analyzed, including the vertical temperature distribution, the longitudinal temperature distribution, smoke layer height and smoke front arrival time. Besides, the effectiveness of exhaust system was evaluated for fire emergency. The results showed that the smoke flow characteristics under different fire scenarios exhibited diversely. Under natural ventilation, the maximum temperature excess near fire source was 18 ℃ and 21℃ in the station hall and platform fire scenarios separately, and the smoke temperature attenuated gradually with the longitudinal distance from fire. Besides, the smoke layer exceeded the height of 4.0 m and 2.8 m when fire in the station hall and platform. After activating the exhaust system in the B-end, it was obvious that the smoke layer height increased and the temperature excess decreased. Additionally, the smoke front arrival time was influenced by the fire source locations and ventilation conditions. In the above scenarios, the smoke diffusion velocity was empirically determined as 0.11–0.18 m/s and 0.21–0.35 m/s when a fire in the station hall and platform respectively. The conclusions from the on-site fire experiment could provide data support for the fire accident emergency in an underground double-island subway station.