Smoke Control in Subway Tunnel Fires

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.

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Safe Evacuation from Subway Station under Platform Train Fire

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.638-640.2023 ◽

2014 ◽

Vol 638-640 ◽

pp. 2023-2026 ◽

Cited By ~ 1

Author(s):

Sheng Zeng ◽

Xiao Xiong Zha ◽

Yi Yan Chen ◽

Rui Juan Jiang

Keyword(s):

Computer Simulation ◽

Theoretical Analysis ◽

Subway Station ◽

Concentration Change ◽

Smoke Control ◽

Fire Dynamics ◽

Fire Temperature ◽

Fire Dynamics Simulator ◽

Environmental Deterioration ◽

Time Calculation

The environmental deterioration of the subway station and the safety of the personnel evacuation under platform train fire are researched. The critical fire danger condition is proposed and the time calculation method of evacuation is determined. A platform train fire in a subway station is simulated by the Fire Dynamics Simulator software. Then the available egress time can be got by analyzing the fire temperature and smoke concentration change with time. At the same time, the required egress time is studied through theoretical analysis and computer simulation by software Building Exodus. The results showed that smoke exhaust rate is very important to the smoke control under platform train fire. And the stair evacuation ability is the key to the whole evacuation.

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Effect Analysis of Different Exhaust Velocity on Fire Smoke Control in Subway Tunnel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.424-425.1224 ◽

2012 ◽

Vol 424-425 ◽

pp. 1224-1227

Author(s):

Xin Han ◽

Xiao Ming Gao ◽

Bei Hua Cong

Keyword(s):

Cfd Simulation ◽

Simulation Analysis ◽

Simulation Method ◽

Subway Tunnel ◽

Control Effect ◽

Smoke Control ◽

Effect Analysis ◽

Longitudinal Ventilation ◽

Fire Smoke ◽

Ventilation Velocity

Taking a subway tunnel as the research object and based on the CFD simulation method, this paper adopts a large eddy simulation analysis software FDS to simulate and analyze the effect of exhaust velocity on fire smoke control under the condition of the same longitudinal ventilation velocity in subway tunnel. The simulated results can provide some reference to design institutes in the selection of exhaust fan. While the longitudinal ventilation velocity set as 1m/s, the simulation results demonstrate that a quite good smoke control effect could be achieved when the exhaust velocity reaches 5 m/s in the smoke exhaust duct

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.831.455 ◽

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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