Full-scale experiment on smoke propagation in metro station tunnel fire under opening the platform screen doors

The study conducted full-scale fire experiments in a representative subway station tunnel to investigate the law of smoke propagation, and three typical ventilation conditions were designed. Under opening the platform screen doors (PSD), the fuel pan was placed at the centerline of the tunnel, and the temperature profile was measured by a series of thermocouples. The vertical temperature distribution, longitudinal temperature distribution and smoke layer height were analyzed based on the measured data in the field. The results showed that the fire-induced smoke propagation was affected significantly by the longitudinal airflow. Under the natural ventilation, the temperature near the fire region was relatively low, and the smoke layer height varied slightly with the distance. Under the mechanical ventilation, the over track exhaust (OTE) system was activated by default, and the mode of the tunnel ventilation fan (TVF) system was changed. When the TVF system in the mode of supply in the A-end and exhaust in the B-end, the smoke distributed within the range of X = 38.5 to 5.5 m. At the location of X = 38.5 m, the smoke layer height was approximately 2 m, which had an impact on the evacuation. When the TVF system in the mode of exhaust at both ends, the smoke gathered at both ends of tunnel, with the smoke layer height of 4.7 m. Therefore, the third ventilation condition performed better owing to its more stable smoke layer and lower temperature. The conclusions from the full-scale fire experiments could provide on-site data for the emergency response during fire accident in metro station tunnels.