Visually activated sprinklers applied in atria to mitigate the interaction of water spray with the smoke layer

This research investigates the fire suppression effectiveness of sprinklers in a large atrium of a public transport hub in Taipei, Taiwan, during a fire using FDS. The thermally-activated sprinkler had the shortcoming of delayed activation, with a thick smoke layer accumulating at the ceiling. Thereafter, the interaction of sprinkler spray with the thick smoke layer would cause a large amount of smoke falling to the floor level, significantly impacting safe egress. The novelty of this study is to couple a sprinkler system with a vision-based fire flame detection system (VFDS) having the advantage of locating the fire instantly to suppress fire. A combination of different atrium heights, fire sizes, and scenarios for a total of 27 cases were investigated. The research results have indicated that VFDS-activated sprinklers can suppress an atrium fire at the early stage, greatly reduce the amount of smoke generation and smoke accumulation. In consequence, the interaction of water spray and smoke layer is largely mitigated to prevent early fall of smoke. When the fire is suppressed, the atrium can maintain a clear height that is crucial to safe egress. The research finding of VFDS-activated sprinklers system is significant for fire safety of buildings with large atria.