Longitudinal ventilation for smoke control in a tilted tunnel by scale modeling

2010 ◽  
Vol 25 (2) ◽  
pp. 122-128 ◽  
Author(s):  
W.K. Chow ◽  
K.Y. Wong ◽  
W.Y. Chung
Keyword(s):  
Smoke Control ◽  
Longitudinal Ventilation ◽  
Scale Modeling

Study of Fire Smoke Flow of Tunnel at Different Longitudinal Ventilation

2012 ◽  
Vol 226-228 ◽  
pp. 1472-1475
Author(s):  
Pei Pei Yang ◽  
Xiao Lu Shi ◽  
Bi Ming Shi
Keyword(s):  
Flow Resistance ◽  
Reverse Flow ◽  
Ventilation System ◽  
Gas Temperature ◽  
Smoke Control ◽  
Smoke Flow ◽  
Longitudinal Ventilation ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Safety Evacuation

Once the tunnel fires happened, it will cause a major accident. And the smoke control of the runnel is important to fire prevention. A numerical simulation of the fire smoke flow in the tunnel model is presented by using FDS. The influence of different longitudinal ventilation on fire smoke flow of tunnel is obtained. And providing theory basis for tunnel ventilation system design, smoke spread control and safety evacuation. The results shown that in order to avoid reverse-flow and extend the time of smoke at the top of tunnel, the longitudinal speed should be controlled in 3.4 m/s; because of the role of longitudinal ventilation, smoke flow resistance and longitudinal ventilation generated by the effect of smoke flow resistance make the gas temperature first rise and then down.

The Study of the Confinement Velocity in the Longitudinal Ventilation Tunnel Fire

2012 ◽  
Vol 446-449 ◽  
pp. 3665-3669
Author(s):  
Ke Qing Sun ◽  
Hui Yang
Keyword(s):  
Characteristic Parameter ◽  
Experimental Models ◽  
Experimental Results ◽  
Mixed Gas ◽  
Control Effect ◽  
Smoke Control ◽  
Tunnel Fire ◽  
Longitudinal Ventilation ◽  
The Relationship ◽  
Two Sides

For the situation that the smoke exhaust vents are located on both sides of the fire source, critical ventilation velocity is not appropriate to evaluate the smoke control effect. “Confinement velocity” is proposed as the characteristic parameter to study the longitudinal ventilation by O.Vauquelin in this situation. However, there have been few studies on confinement velocity. An experimental study was carried out on two reduced scale tunnel models. The main objective is to analysis the relationship between confinement velocity and fire heat release in this situation. Helium and air in different ratio was used as the smoke, and the "cold smoke" produced by smoke generator was put into the mixed gas in order to measure the length of smoke layer. The experimental models were based on the half tunnel as flow field at two sides of fire is symmetrical. The CFD model was created on the basis of the experiment, and the results were basically accord with the experimental results. It was shown from the experimental results that the critical point of the confinement velocity is between L / H = 2 to L / H = 4 in section 1, between L / H = 1 to L / H = 2 in section 2, rather than a fixed value; Two tunnel models had similar dimensionless confinement velocity, but the dimensionless total confinement velocity was different.

scholarly journals Longitudinal Ventilation for Smoke Control of Urban Traffic Link Tunnel: Hybrid Field-network Simulation

2014 ◽  
Vol 84 ◽  
pp. 586-594 ◽  
Author(s):  
Du Tao ◽  
Yang Dong ◽  
Peng Shini ◽  
Xiao Yimin ◽  
Zhang Fan
Keyword(s):  
Network Simulation ◽  
Urban Traffic ◽  
Smoke Control ◽  
Longitudinal Ventilation ◽  
Field Network

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

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

A Study on Tunnel Smoke Control Strategies by Experiment and Numerical Simulation

2011 ◽  
Vol 402 ◽  
pp. 864-867
Author(s):  
Xiao Yang Liu ◽  
Jing Yan Zhang ◽  
Yan Feng Li ◽  
Li Li Zhang ◽  
Jin Feng Yuan
Keyword(s):  
Scale Model ◽  
Road Tunnel ◽  
Smoke Control ◽  
Fire Control ◽  
Fire Dynamics ◽  
Tunnel Fire ◽  
Longitudinal Ventilation ◽  
Fire Smoke ◽  
Smoke Layer ◽  
Layer Velocity

In order to meet the need of the study on the tunnel fire safety system, taking the tunnel laboratory bench in the key laboratory of the university of science and technology of China as the object, this paper does a scale model experiment on the tunnel fire, and uses the Fire Dynamics Simulator（FDS）software to simulate fire smoke layer velocity under different longitudinal ventilation control, by comparing the experimental and simulation results, this paper not only gives the variation law of the tunnel fire smoke layer velocity under different longitudinal ventilation speed, but also proposes the concept of the smoke stratification critical wind speed , which will provide some references for the road tunnel fire control, rescue and evacuation.

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