Full-scale experimental study on thermal smoke movement characteristics in an indoor pedestrian street

Indoor pedestrian street, a common architecture scheme, brings both convenience and fire risk in the meantime. Full-scale tests were carried out to study thermal smoke movement characteristics, including smoke development, longitudinal temperature distribution in the room, and horizontal temperature distribution in the ring corridor, in an indoor pedestrian street under different mechanical smoke exhaust modes. Results showed that smoke movement characteristics were mainly influenced by the smoke exhaust mode and building structure. Under natural ventilation, thermal smoke spread along the two crossed channels of the room and entered the adjacent ring corridor and atrium. When the smoke exhaust system was activated, the smoke spread was effectively restricted. As the smoke exhaust was enhanced, the heat release rate of the ventilation controlled fire in the room was increased, resulting in the higher smoke temperature. In addition, the smoke temperature rise decreased exponentially with the increasing longitudinal distance from the fire in the room under all smoke exhaust modes. The stronger smoke exhaust and larger building space leaded to the higher decay rate. In the ring corridor, the decrease of smoke temperature rise with the horizontal distance was exponential under natural ventilation but was linear when the smoke exhaust system was activated.