Experimental study of heat exhaust efficiency with natural ventilation in tunnel fire: Impact of shaft height and heat release rate

2020 ◽  
Vol 201 ◽  
pp. 104173 ◽  
Author(s):  
Lu He ◽  
Zhisheng Xu ◽  
Frank Markert ◽  
Jiaming Zhao ◽  
Qiulin Liu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Natural Ventilation ◽  
Tunnel Fire ◽  
Fire Impact

Scale Modeling on the Effect of Air Velocity on Heat Release Rate in Tunnel Fire

2008 ◽  
Vol 18 (2) ◽  
pp. 111-124 ◽  
Author(s):  
C. Chen ◽  
L. Qu ◽  
Y. X. Yang ◽  
G. Q. Kang ◽  
W. K. Chow
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Air Velocity ◽  
Tunnel Fire ◽  
Scale Modeling

Experimental Study on Variation of Gas and Heating Capacity about a Combustible Organic Rock

2014 ◽  
Vol 962-965 ◽  
pp. 1025-1028
Author(s):  
Xiao Feng Ma
Keyword(s):  
Experimental Study ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Production Rates ◽  
Organic Sample ◽  
Heating Capacity

the paper determines and calculates variation of gas and heating capacity in a combustible organic rock, the experiment shows that organic sample radiating intensity is low when temperature is below 110 °C, it gradually increased more than 110 °C when the heat release rate increases considerably. the speed of CO and CO2production rates increased slowly nevertheless the temperature is up to 65°C and raised faster and finally enhanced dramatically. Organic rock combustion can be inhibited effectively by lowering the temperature and reduce Organic Rock oxidation velocity.

Experimental Study on Effect of Ceiling on Upward Flame Spread over Poly(Methyl Methacrylate) Sheets

2016 ◽  
Vol 705 ◽  
pp. 114-118 ◽  
Author(s):  
Fei Peng ◽  
Li Zhong Yang ◽  
Xiao Dong Zhou
Keyword(s):  
Experimental Study ◽  
Heat Release ◽  
Heat Release Rate ◽  
Flame Spread ◽  
Release Rate ◽  
Unit Area ◽  
Sample Length ◽  
Upward Flame Spread ◽  
Series Of Experiments ◽  
Sample Width

A series of experiments was designed to investigate the effects of ceiling on upward flame spread. The result reveals that the ceiling accelerates the burning rate of upward flame under certain situations. And the acceleration is slightly increase with the increasing sample length, but almost keeps the same with different sample width. The heat release rate per unit area nearly keeps the same for the series work with ceiling or the series work without ceiling. But the heat release rate per unit area between the two series is obvious, the heat release rate per unit area with ceiling is much higher than the ones without ceiling.

scholarly journals Experimental Study on Occurrence Limit Heat Release Rate of Flashover in a Building Fire

2021 ◽  
Vol 21 (2) ◽  
pp. 65-71
Author(s):  
Seunggoo Kang ◽  
Yi Chul Shin
Keyword(s):  
Experimental Study ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Large Scale ◽  
Fire Behavior ◽  
Design Calculation ◽  
Building Fire ◽  
Fire Source ◽  
Combustion Tests

In this study, to allow the flashover to occur, combustion tests were conducted by setting the conditions of a fire source using a large-scale compartment and changing the opening condition. As a result, the inside temperature of the compartment was measured under the fire source conditions. Moreover, according to the “Handbook on Design Calculation &#x0004d;ethods of Fire Behavior” by the Architectural Institute of Japan, the validity of the heat release rate required for the flashover to occur was verified through the correlation between <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>Q</mi><mrow><mi>F</mi><mi>O</mi></mrow></msub><mo>/</mo><msub><mi>Q</mi><mrow><mi>v</mi><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>A</mi><mi>T</mi></msub><msup><mrow><mo>(</mo><mi>k</mi><mi>p</mi><mi>c</mi><mo>)</mo></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup><mo>/</mo><msub><mi>c</mi><mrow><mi>P</mi></mrow></msub><mn>0</mn><mo>.</mo><mn>5</mn><mi>A</mi><msup><mi>H</mi><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></math>.

Numerical Simulation and Analysis of Critical Velocity in Tunnel Fires Based on FDS

2013 ◽  
Vol 831 ◽  
pp. 455-459
Author(s):  
Shu Hui Xu ◽  
Ling Fei Cui ◽  
Lei Ning ◽  
Zi Ye Wang
Keyword(s):  
Heat Release ◽  
Critical Velocity ◽  
Heat Release Rate ◽  
Release Rate ◽  
Small Scale ◽  
Smoke Control ◽  
Tunnel Fires ◽  
Tunnel Fire ◽  
Velocity Prediction ◽  
The One

Critical velocity is a very important parameter in smoke control of tunnel fires and the variation of critical velocity against fire heat release rate is also one of the most important issues in tunnel fire researches. In this paper, a simplified physical model of a tunnel was established and the predictions of critical velocity for fire sizes in the 5-100MW range were carried out by FDS simulations. The FDS-predicted dimensionless critical velocities were compared with the values calculated by Wu and Bakar’s model. The result indicated that when the heat release rate was relatively small, Q≤30MW, the critical velocity increased with the increasing of heat release rate and varied as the one-third power of the heat release rate; when Q≥40MW, the growth rate of critical velocity became very small; after Q reach to 60MW, the critical velocity was almost unchanged with the increasing of heat release rate. In addition, the values of critical velocity calculated by Wu and Bakar’model which was derived from small-scale gas fire tests were underestimated. Therefore, the model suggested by Wu and Bakar is not suitable for critical velocity prediction in tunnel fires.

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