A Study on Road Tunnel Fires Using Hazmat, with Emphasis on Critical Ventilation Velocity

2005 ◽  
Vol 83 (5) ◽  
pp. 443-451 ◽  
Author(s):  
E. Palazzi ◽  
F. Currò ◽  
B. Fabiano
Keyword(s):  
Road Tunnel ◽  
Tunnel Fires ◽  
Ventilation Velocity

A novel representation of the critical ventilation velocity for mitigating tunnel fires

2021 ◽  
Vol 112 ◽  
pp. 103853
Author(s):  
S.K. Khattri ◽  
T. Log ◽  
A. Kraaijeveld
Keyword(s):  
Tunnel Fires ◽  
Ventilation Velocity

scholarly journals The effect of technical installations on evacuation performance in urban road tunnel fires

2021 ◽  
Vol 107 ◽  
pp. 103608 ◽  
Author(s):  
Yuxin Zhang ◽  
Hehua Zhu ◽  
Qinghua Guo ◽  
Ricky Carvel ◽  
Zhiguo Yan
Keyword(s):  
Road Tunnel ◽  
Urban Road ◽  
Tunnel Fires

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.

scholarly journals Numerical Study of Large-Scale Fire in Makkah’s King Abdulaziz Road Tunnel

Fluids ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 5
Author(s):  
Kamel Guedri ◽  
Abdullah A. Abdoon ◽  
Omar S. Bagabar ◽  
Mowffaq Oreijah ◽  
Abdessattar Bouzid ◽  
...  
Keyword(s):  
Large Scale ◽  
Unit Area ◽  
Numerical Study ◽  
Human Life ◽  
Gas Temperature ◽  
Road Tunnel ◽  
Air Velocity ◽  
Fire Dynamics ◽  
Tunnel Fires ◽  
Heat Released

Tunnel fires are one of the most dangerous catastrophic events that endanger human life. They cause damage to infrastructure because of the limited space in the tunnel, lack of escape facilities, and difficulty that intervention forces have in reaching the fire position, especially in highly crowded areas, such as Makkah in the Hajj season. Unfortunately, performing experimental tests on tunnel fire safety is particularly challenging because of the prohibitive cost, limited possibilities, and losses that these tests can cause. Therefore, large-scale modeling, using fire dynamic simulation, is one of the best techniques used to limit these costs and losses. In the present work, a fire scenario in the Makkah’s King Abdulaziz Road tunnel was analyzed using the Fire Dynamics Simulator (FDS). The effects of the heat released per unit area, soot yield, and CO yield on the gas temperature, radiation, concentrations of the oxygen and combustion products CO and CO2, and air velocity were examined. The results showed that the radiation increased with the heat released per unit area and the soot yield affected all parameters, except the oxygen concentration and air velocity. The CO yield significantly affects CO concentration, and its influence on the other studied parameters is negligible. Moreover, based on the validation part, the results proved that FDS have limitations in tunnel fires, which impact the smoke layer calculation at the upstream zone of the fire. Therefore, the users or researchers should carefully be concerned about these weaknesses when using FDS to simulate tunnel fires. Further comprehensive research is crucial, as tunnel fires have severe impacts on various aspects of people’s lives.

Determination of the applicable exhaust airflow rate through a ventilation shaft in the case of road tunnel fires

2010 ◽  
Vol 48 (6) ◽  
pp. 722-728 ◽  
Author(s):  
Ju-seog Ko ◽  
Chan-hoon Yoon ◽  
Sung-wook Yoon ◽  
Jin Kim
Keyword(s):  
Airflow Rate ◽  
Road Tunnel ◽  
Tunnel Fires ◽  
Ventilation Shaft

Critical ventilation velocity of two fire sources with different separating distances in road tunnel

2019 ◽  
Vol 37 (4-6) ◽  
pp. 320-339 ◽  
Author(s):  
Shaogang Zhang ◽  
Long Shi ◽  
Jinhui Wang ◽  
Xianbin Li ◽  
Yuedong Han ◽  
...  
Keyword(s):  
Critical Velocity ◽  
Empirical Model ◽  
High Probability ◽  
Experimental Validation ◽  
Road Tunnel ◽  
Fire Propagation ◽  
Fire Plumes ◽  
Fast Decrease ◽  
Numerical Tool ◽  
Ventilation Velocity

Critical ventilation velocity is an important parameter for the design of road tunnel, while the situation of two fire sources should be considered due to the high probability of two crashed vehicles or fire propagation. The influences of separating distance between two fire sources on the critical ventilation velocity were investigated numerically after the experimental validation of numerical tool. The trend of the dimensionless critical velocity along the separating distance can be divided into three regions, including limited influence, fast decrease, and slight fluctuation. As the separating distance keeps increasing, the fire plumes transform from completely merged to completely separate. The different merging behaviors of fire plumes are the main reasons of showing various critical ventilation velocities with different separating distances. Finally, an empirical model was developed to predict the dimensionless critical ventilation velocity of double fire sources with different separating distances in the longitudinally ventilated road tunnel.

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.

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