Investigation on Smoke Flow in Stairwells induced by an Adjacent Compartment Fire in High Rise Buildings

Jun Zhang,Tiannian Zhou,Dongxu Ouyang,Jian Wang,Jingwen Weng,Ruichao Wei,Qinpei Chen

doi:10.3390/app9071431

Abstract

The aim of this study was to evaluate the transport phenomena of smoke flow and vertical temperature distribution in a 21-story stairwell with multiple fire locations and openings. A large eddy simulation (LES) method was used to model the smoke flow in a stairwell model with a set of simulation parameters, wherein the fire heat release rate (HRR) and fire location were varied. Based on the results, a wall attachment effect was found in three-dimensional figures. Moreover, with an increase in the fire HRR, the effects were more pronounced. The simulation results verified that the vertical temperature distribution is an index model with a natural logarithm, where the pre-finger factor and attenuation coefficient increase considerably in accordance with an increase in the fire HRR. Moreover, there was a decrease in the maximum temperature (Tm) with an increase in the fire location factor (h*) due to the upward thermal smoke. Moreover, heat mainly accumulates in the area above a fire source. However, h* has a slight influence on the time required to reach Tm within the range of 53–64 s. Furthermore, the direction of the airflow at each side opening in the stairwell varied in accordance with the variation in the fire location changes, and a regular calculation was carried out.

Highlights

In recent years, a significant number of skyscrapers have been constructed to fully utilize vertical space and to reduce land occupation
The results revealed that the heat release rate (HRR) has a significant effect on the distribution of the smoke, temperature, and velocity
The results indicated that the upper average smoke temperatures in the fire room decrease with an increase in the HRR, and the heat pressure induced by smoke in the stairwell increases with an increase in the HRR and opening height

Summary

Introduction

A significant number of skyscrapers have been constructed to fully utilize vertical space and to reduce land occupation. There are several fire safety problems in relation to high rise buildings [1,2,3,4,5]. The fire spread to the 28th floor in less than 4 minutes with the help of stack effects; the majority of people had no time to escape. Another significant case is that of the closed-circuit television (CCTV) Cultural Center Building fire, which led to 17 casualties and economic losses of 160 million yuan in 2009 [6]. Casualties caused by smoke account for approximately 40–70% of fire-related casualties in high-rise buildings.

Objectives

Results

Conclusion