Visualization study on the effect of ambient wind on smoke layer height in chamber fires under natural smoke exhaust condition

2021 ◽  
Vol 208 ◽  
pp. 104458
Author(s):  
Liang Yi ◽  
Yijun Chen ◽  
Rongwei Bu ◽  
Chang Luo ◽  
Yang Zhou
Keyword(s):  
Layer Height ◽  
Ambient Wind ◽  
Smoke Layer

Determinations of the fire smoke layer height in a naturally ventilated room

2013 ◽  
Vol 58 ◽  
pp. 1-14 ◽  
Author(s):  
Chi-ming Lai ◽  
Chien-Jung Chen ◽  
Ming-Ju Tsai ◽  
Meng-Han Tsai ◽  
Ta-Hui Lin
Keyword(s):  
Layer Height ◽  
Fire Smoke ◽  
Smoke Layer

scholarly journals Experimental Investigation on the Discharge of Pollutants from Tunnel Fires

2020 ◽  
Vol 12 (5) ◽  
pp. 1817
Author(s):  
Lihua Zhai ◽  
Zhongxing Nong ◽  
Guanhong He ◽  
Baochao Xie ◽  
Zhisheng Xu ◽  
...  
Keyword(s):  
Laser Sheet ◽  
Longitudinal Velocity ◽  
Release Rates ◽  
Layer Height ◽  
Tunnel Fires ◽  
Smoke Flow ◽  
Longitudinal Ventilation ◽  
Toxic Gases ◽  
Smoke Layer ◽  
Series Of Experiments

Many pollutants are generated during tunnel fires, such as smoke and toxic gases. How to control the smoke generated by tunnel fires was focused on in this paper. A series of experiments were carried out in a 1:10 model tunnel with dimensions of 6.0 m × 1.0 m × 0.7 m. The purpose was to investigate the smoke layer thickness and the heat exhaust coefficient of the tunnel mechanical smoke exhaust mode under longitudinal wind. Ethanol was employed as fuel, and the heat release rates were set to be 10.6 kW, 18.6 kW, and 31.9 kW. The exhaust velocity was 0.32–3.16 m/s, and the longitudinal velocity was 0–0.47 m/s. The temperature profile in the tunnel was measured, and the buoyant flow stratification regime was visualized by a laser sheet. The results showed that the longitudinal ventilation leads to a secondary stratification of the smoke flow. In the ceiling extract tunnel under longitudinal ventilation, considering the research results of the smoke layer height and the heat exhaust coefficient, a better scheme for fire-producing pollutants was that an exhaust velocity of 1.26–2.21 m/s (corresponding to the actual velocity of 4.0–7.0 m/s) should be used. The longitudinal velocity should be 0.16–0.32 m/s (corresponding to the actual velocity of 0.5–1.0 m/s).

Experimental investigation on smoke spread characteristics and smoke layer height in tunnels

2019 ◽  
Vol 43 (3) ◽  
pp. 303-309 ◽  
Author(s):  
Zhisheng Xu ◽  
Jiaming Zhao ◽  
Qiulin Liu ◽  
Hongguang Chen ◽  
Yaohui Liu ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Layer Height ◽  
Smoke Spread ◽  
Smoke Layer

A Study Regarding Smoke Exhaust from an Atrium Type Building in a Fire Situation

2017 ◽  
Vol 21 ◽  
pp. 15-21
Author(s):  
Zeno Cosmin Grigoraş ◽  
Dan Diaconu-Şotropa
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Fluid Flow ◽  
Computer Program ◽  
Maximum Temperature ◽  
Layer Height ◽  
European Legislation ◽  
Smoke Layer

This paper presents the analysis of the effect of smoke exhaust and hot gases from an atrium type building using techniques for numerical simulation of a fire situation. Several scenarios regarding smoke exhaust are considered for that purpose and the variation of the following parameters is monitored: minimum and maximum temperature of hot gases as well as the smoke layer height inside the atrium. Using engineering techniques, the development of fire, in compliance with the European legislation has been modelled, by means of a specialized computer program in order to simulate the phenomena of both the fluid flow and the heat transfer manifested in a fire situation.

An Analysis of Factors Affecting Available Safe Escape Time

2014 ◽  
Vol 1001 ◽  
pp. 267-271 ◽  
Author(s):  
Vladimír Mózer
Keyword(s):  
Computer Model ◽  
Escape Time ◽  
Design Codes ◽  
Fire Growth ◽  
Factors Affecting ◽  
Layer Height ◽  
Standard Fire ◽  
Smoke Layer ◽  
Individual Variables ◽  
Model Scenarios

This paper deals with some of the parameters that affect the available safe evacuation time (ASET), including fire growth rate, enclosure area, and thermal properties of the bounding construction. Although the available safe escape time is a crucial design parameter, it is, or has to be, often generalised to cover a range of scenarios; this is also the case of design codes. It is therefore necessary to be aware in which aspects such generalisation is possible. A set of computer model cases, carried out in CFAST, is analysed and the effect of individual variables quantified. As real fires usually grow exponentially with time, the t2-fire model was used, employing the standard fire growth rates. By analysing the computer model scenarios, it was found that increasing the size of the enclosure does not bring proportional growth of available safe escape time. It is the rate of fire growth that is the primary factor affecting the safe available escape time. Two different smoke layer height tenability criteria – 0.9m and 1.5m – are also compared; the first derived from literature and the latter represent a more conservative estimate.

Justification of a Fire Model on Predicting Fire in Large Room

2012 ◽  
Vol 193-194 ◽  
pp. 1103-1108
Author(s):  
Shu Sheng Li ◽  
Ye Gao ◽  
Gao Wan Zou ◽  
Yan Huo
Keyword(s):  
Fire Test ◽  
Cfd Model ◽  
Layer Height ◽  
Fire Model ◽  
Fire Models ◽  
Air Temperatures ◽  
Fire Environment ◽  
Smoke Layer ◽  
Computational Fluid Dynamics Cfd ◽  
Microscopic Picture

Fire models using Computational Fluid Dynamics (CFD) are now popular design or evaluation tools as the computer’s development sharply. By those tools the thermal fire environment can be predicted in a ‘microscopic’ picture with air flow pattern, pressure and temperature contours. However, most of the fire models are only validated by some experiments not specially designed for such purpose, especially for large rooms. In this paper, an existing fire test was used to justify a fire model - FDS4.07 on predicting fires in large room. Smoke layer height and air temperatures inside the room were taken as the parameters. Functional analysis was applied to justify the predictions by the CFD model.

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