Narrow Results

Transient 3-D numerical simulations were performed to analyze the fire safety in a long railroad tunnel equipped with the mechanical ventilation system using dampers and jet fans. The flow behaviors of heat and pollutants were investigated for various emergency operation modes of the ventilation system in a rescue station and escape route in the long railroad tunnel in case of fire. The results showed that the ventilation mode, which extracts heat and pollutants from the tunnel on fire and pressurizes the opposite tunnel, was very effective for the fire safety of the rescue station. To evaluate the ventilation efficiency of the escape route, various geometries such as connection and slope angles of the escape route were considered. The importance of the jet fan operation in the escape tunnel on the ventilation performance was also discussed in detail.

Full evacuation is a key concern for supertall buildings due to the high population density and long travel distance. Using the elevator would speed up evacuation, but there are fire safety concerns. A design of fire safe elevator system combining the refuge place with fire safe elevator is studied. In the proposed design, fire safe elevator is surrounded by the refuge places with at least 2 hours’ fire resistance rating. During the fire, the elevators would be controlled to stop only at the stories with refuge places. This arrangement can protect both the occupants and the elevators. Smoke spread to the system is studied by the Computational Fluid Dynamics (CFD) code Fire Dynamics Simulator (FDS). Different arrangements of smoke extraction with pressurization systems are evaluated by analyzing the smoke dispersion and pressure distributions in this fire safe elevator system.