Using Fire Dynamics Simulator to reconstruct a fire scene in a hospital-based long-term care facility

Abstract

This study conducted a fire scene reconstruction on the seventh floor of a long-term care facility in a hospital in New Taipei City, Taiwan, using the Fire Dynamics Simulator software tool and applying computational fluid dynamics. The location of the point of origin and the cause of fire was determined based on the fire scene investigation and an official fire investigation report. Through a computer simulation, this study revealed that if a partition wall inside a room was not fully attached to the upper floor, or no fire protection stuffing was employed in the through-penetrations and construction openings inside a partition wall, thick smoke would diffuse and spread through these channels. Its flow would be accelerated by the self-contained air-conditioning unit in each room. In the rooms that were on fire, thick smoke entered from above the decorative ceiling through a return air vent, and it was then absorbed by a self-contained air-conditioning unit before exiting through an air outlet and channeled to other rooms, which complicated the evacuation of the persons in the affected rooms. On the basis of an analysis of the blaze and the flow of smoke layers, the recommended emergency egress time for rooms on fire (A = 35.13 m2, H = 2.8 m) was 179 s after fire occurrence. Even if the doors of a room on fire were closed, thick smoke still traveled to other rooms through air inlets, return air vents, and the compartment above the decorative ceiling that was not connected to the actual ceiling. The mortality rate of the residents who failed to evacuate in time increased due to the inhalation of excessive thick smoke. Therefore, responders should shut the doors of each room after completing an evacuation. In addition, the various aspects of the overall building structure, partition walls that connect to the ceiling, fire safety equipment, thorough implementation of educational training, and fire risk management should be considered.