Critical ventilation velocity for multi-source tunnel fires

2010 ◽  
Vol 98 (10-11) ◽  
pp. 650-660 ◽  
Author(s):  
Kuang-Chung Tsai ◽  
Hon-Hsiang Chen ◽  
Shin-Ku Lee
Keyword(s):  
Tunnel Fires ◽  
Ventilation Velocity

Smoke Control in Subway Tunnel Fires

2014 ◽  
Vol 638-640 ◽  
pp. 2027-2030
Author(s):  
Xiao Xiong Zha ◽  
Sheng Zeng ◽  
Yi Yan Chen ◽  
Rui Juan Jiang
Keyword(s):  
Computer Simulation ◽  
Theoretical Analysis ◽  
Critical Velocity ◽  
Simple Formula ◽  
Control Mode ◽  
Subway Tunnel ◽  
Smoke Control ◽  
Release Rates ◽  
Tunnel Fires ◽  
Ventilation Velocity

This paper concerns the smoke control modes and the critical ventilation velocity when the subway tunnel on fires. The standard for the smoke control mode is making sure the smoke exhausting in the shortest way. The critical ventilation velocity means it is just sufficient to prevent the smoke spreading upstream. The critical velocity in different heat release rates obtained though theoretical analysis and computer simulation. In the end, a simple formula to calculate the critical velocity can be fitting out.

Reduced-Scale Model Tests of Fires in Railway Tunnel and Structure Fire Safety

2010 ◽  
Vol 168-170 ◽  
pp. 2473-2476 ◽  
Author(s):  
Hong Li Zhao ◽  
Zhi Sheng Xu ◽  
Xue Peng Jiang
Keyword(s):  
Fire Safety ◽  
Numerical Models ◽  
Scale Model ◽  
Railway Tunnel ◽  
Tunnel Fires ◽  
Tunnel Fire ◽  
Longitudinal Ventilation ◽  
Overall Stability ◽  
Reduced Scale ◽  
Ventilation Velocity

The high-temperature toxic gas released by long railway tunnel fires not only causes great harm to persons, but also damages the structure of the tunnel which will reduce the overall stability of tunnel. In order to diminish the damage to tunnel structure produced by a tunnel fire, on the basis of the first extra-long underwater railway tunnel in China, some reduced-scale tests were carried out to study the distribution of smoke temperature along the tunnel ceiling, the smoke velocity and the backlayering distance with the fire size of 63KW. The longitudinal ventilation velocity and the tunnel gradient varied in these tests. The smoke temperature below the tunnel ceiling in different times and under different longitudinal ventilation velocity, the smoke velocity under the ceiling, and the backlayering distance in the presence of different ventilation velocity are acquired from the tests. The conclusions have the guiding meaning to the disaster prevention design and construction of structure fire safety in tunnel fires, and all the experimental data presented in this paper are applicable for the verification of numerical models.

Smoke Propagation in an Inclined Semi-Circular Long Tunnel

2012 ◽  
Vol 446-449 ◽  
pp. 2143-2148 ◽  
Author(s):  
Jik Chang Leong ◽  
C.L. Chang ◽  
Y. C. Chen ◽  
L.W. Chen
Keyword(s):  
Propagation Rate ◽  
Fire Size ◽  
Tunnel Fires ◽  
Temperature Distributions ◽  
Break Up ◽  
Ventilation Velocity

This work used FDS to simulate tunnel fires occur in a semi-circular longitudinally ventilated tunnel. By varying the parameters such as the tunnel gradient, the fire size, and the ventilation velocity, their influence on the backlayering effect and downstream propagation rate can be recognized. Under weak ventilation, the backlayering effect either advances or vanishes depending on the slope of the tunnel. Under stronger ventilation, the backlayering effect would break up. The temperature distributions may become less and less dependent on the tunnel gradient when the ventilation velocity is increased. Although the hot gases and smoke in uphill tunnels propagate faster than those in downhill tunnels, their difference reduces with ventilation velocity.

An experimental study on the effect of ventilation velocity on burning rate in tunnel fires—heptane pool fire case

2008 ◽  
Vol 43 (7) ◽  
pp. 1225-1231 ◽  
Author(s):  
Jae Seong Roh ◽  
Seung Shin Yang ◽  
Hong Sun Ryou ◽  
Myong O Yoon ◽  
Youn Tae Jeong
Keyword(s):  
Experimental Study ◽  
Burning Rate ◽  
Pool Fire ◽  
Tunnel Fires ◽  
Ventilation Velocity

An experimental study on the effects of blockage ratio and ventilation velocity on the heat release rate of tunnel fires

2011 ◽  
Vol 29 (6) ◽  
pp. 555-575 ◽  
Author(s):  
Serkan Kayili ◽  
Ahmet Yozgatligil ◽  
O. Cahit Eralp
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Scaled Model ◽  
Wood Crib ◽  
Cross Sectional ◽  
Tunnel Fires ◽  
Longitudinal Ventilation ◽  
The Impact ◽  
Ventilation Velocity

It is very important to accurately predict the fire-induced air velocity, temperature, and smoke concentrations in tunnel fires to design efficient fire protection systems. In this study a scaled model of a tunnel was constructed based on Froude number scaling and wood sticks with different configurations which were burned in a controlled environment. Model vehicles having a square base were built according to the wood crib theory. The impact of varying longitudinal ventilation velocity and the cross-sectional area of the burning substances on the heat release rate and temperature distribution in the tunnel were measured.

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