Influence of the train running on the fire smoke spread characteristics in the rescue station

2021 ◽  
pp. 1-16
Author(s):  
Yuanlong Zhou ◽  
Honglin Wang ◽  
Haiquan Bi
Keyword(s):  
Smoke Spread ◽  
Fire Smoke

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.

Dimensionless analytical solutions for steady-state fire smoke spread through high-rise shaft

2017 ◽  
Vol 93 ◽  
pp. 12-20 ◽  
Author(s):  
Dahai Qi ◽  
Liangzhu (Leon) Wang ◽  
Jie Ji ◽  
Man Li
Keyword(s):  
Steady State ◽  
Analytical Solutions ◽  
High Rise ◽  
Smoke Spread ◽  
Fire Smoke

Numerical Analysis on the Effect of Thermal Insulation of Closure on Fire Smoke Spread Rate in Building's Corridor

2014 ◽  
Vol 513-517 ◽  
pp. 2635-2638
Author(s):  
Xuan Wei Peng
Keyword(s):  
Numerical Analysis ◽  
Thermal Insulation ◽  
Air Temperature ◽  
Spread Rate ◽  
Smoke Flow ◽  
External Insulation ◽  
Flow Prediction ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Fire Ignition

The corridor is an important way of evacuation and rescue in building fire. The fire smoke flow prediction software developed successfully was applied to simulate a building with a 28.8 meters long corridor to investigate the effect of the different thermal insulation on fire smoke spread rate. Two representative thermal insulation, external insulation and internal insulation were compared. In 3600s fire time, air temperature in the corridor of external insulation is much lower than that of internal insulation. The air temperature gap gets narrowed between the two insulation methods in the corridor with the prolongation of fire time. Temperature difference increases as the distance increase from the fire ignition place. The corridor gets unsafe of internal insulation in 7 minute since fire ignition, while about half the length of the corridor stay secure of external insulation in 10 minutes since fire ignition. That implies more available safe egress time can be gained with external insulation than internal insulation. Smoke spread rate was numerically compared based on the air temperature variation. Smoke spread rate of internal insulation is much higher than that of external insulation and the corresponding ratio is 1.732:1.

scholarly journals Numerical simulation on the characteristics of smoke exhaust effect with different sets of smoke vent in deep buried inclined channel fire

2021 ◽  
Vol 252 ◽  
pp. 02050
Author(s):  
Lu Yuhan ◽  
Weng Miao cheng ◽  
Liu Fang
Keyword(s):  
Control Effect ◽  
Smoke Control ◽  
Metro Station ◽  
Thermal Buoyancy ◽  
Average Temperature ◽  
Fire Source ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Fire Characteristics ◽  
Better Than

Deep buried metro stations require longer and more inclined exit passages to connect with the outside. The fire characteristics of these inclined and narrow passages are significantly different from those of above-ground or shallow buried metro station exit passages, and at the same time fires in those inclined channels have a greater risk. This paper takes a channel of deep buried tunnel station in Chongqing as an example and simplifies the actual passage to establish a 3D model to study the smoke spread characteristics along the passage with different smoke vent characteristics including shape and location by FDS, as well as temperature distribution characteristic under different working conditions. The results show that: after a fire, smoke will spread upwards rapidly under the action of thermal buoyancy, and mechanical smoke exhaust plays a certain role in controlling smoke, which is more obvious at the beginning of the fire; there are differences in the smoke exhaust efficiency of different smoke extraction openings shape, but the differences are small, and square smoke vents have a slightly better effect on smoke control than other shapes of smoke vents; changing the location of smoke outlets has a greater impact on the environment in the tunnel. When the smoke vent is located directly above the fire source, the mechanical smoke control effect is significantly better than other positions, and as the distance between smoke vent and fire source increases, the average temperature along the passage increases. At the same time, because of the pressure difference after the fire, the emergency staircase and the upstream of the fire source are basically unaffected by smoke.

scholarly journals Research on factors affecting bus fire based on numerical simulation

2021 ◽  
Vol 303 ◽  
pp. 01042
Author(s):  
Min Xu ◽  
Pengyi Bu ◽  
Lin Xin ◽  
Chao Li ◽  
Limin Han ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Heating Rate ◽  
Rapid Development ◽  
Factors Affecting ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Co Concentration ◽  
In Fire

With the rapid development of economy, the number of buses and bus fire increases. This paper takes bus as the research object and uses software FDS to explore the fire smoke spread under different fire power conditions. The results show that: with the increase in fire power, the smoke in the compartment rapidly accumulates, and the heating rate is also accelerated. The visibility decreases with the diffusion of smoke in the compartment. The CO concentration increases with time. The greater the fire power, the higher the temperature which will eventually stabilize. Only the concentration of smoke near the entrance will be slightly reduced. This is also conducive to the escape of people inside the car.

scholarly journals Effects of Fire Compartmentation and Smoke Exhaust Measures on Smoke Spread Caused by Cable Fire in Utility Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Li Xin ◽  
Zhang Yuanyuan ◽  
Jia Boyan ◽  
Zhang Guowei ◽  
Zheng Li
Keyword(s):  
Prevention And Control ◽  
Simulation Software ◽  
Normal Operation ◽  
Spread Rate ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Utility Tunnel ◽  
Smoke Prevention ◽  
And Control ◽  
Fire Door

Investigating the behavior of fire smoke in utility tunnel as well as smoke prevention and control measures are of vital significance for exhausting smoke from utility tunnel, realizing efficient firefighting and rescue, and guaranteeing the normal operation of cities. Taking utility tunnel as the research background, this paper builds a simulation calculation model for fire smoke prevention and control in the utility tunnel using PyroSim numerical simulation software and explores the rules of smoke spread under conditions such as building ceiling screen, changing fire compartmentation tightness, and adding smoke exhaust facilities. According to study results, before the tunnel was filled with smoke, ceiling screens lowered smoke spread rate, and smoke spread rate was inversely proportional to the ceiling screen height. When the fire door was opened, fire smoke spread to the adjacent fire compartment, and smoke spread rate was directly proportional to the fire door opening angle. Before the tunnel was filled up, mechanical smoke exhaust facilities significantly lowered the smoke spread rate by as much as 50%. When the entire tunnel was full of smoke, mechanical smoke exhaust facilities significantly reduced the smoke concentration in the utility tunnel; smoke layer temperature dropped by as much as 32°C, while visibility improved by as much as 66%. By studying smoke spread in utility tunnel, this paper aims to determine the optimal measures of preventing and controlling smoke spread in utility tunnel. This paper could also offer some reference for practical engineering applications in smoke prevention and control in utility tunnel.

Analysis of Fire Smoke Control System of under Construction Tunnel

2012 ◽  
Vol 594-597 ◽  
pp. 1245-1250
Author(s):  
Jia Yun Sun ◽  
Zheng Fang ◽  
Jian Ping Yuan
Keyword(s):  
Control System ◽  
Ventilation Rate ◽  
Smoke Control ◽  
Smoke Movement ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Under Construction ◽  
Smoke Control System ◽  
Distinguishing Features ◽  
Ventilation Systems

Compared with operated tunnel, one of the distinguishing features of a tunnel during construction is its single-ended geometry. The direction of fire smoke movement is the same as the direction for worker to evacuate the tunnel. This paper calculates fire-induced conditions, including temperature, smoke movement and visibility, which are influenced by two different ventilation systems. According to the simulation, when the fire located at bottom of tunnel, forced extraction is more effective; when the fire located at middle of tunnel, forced injection can protect workers in tunnel. Besides，increasing ventilation rate can control smoke spread effectively.

Atrium-Corridor Structure Fire Smoke Simulation

2012 ◽  
Vol 198-199 ◽  
pp. 781-785
Author(s):  
Wen Si Liu ◽  
Chen Hua Zhong ◽  
Zhi Qing Yang ◽  
Li Wei Wang
Keyword(s):  
Single Factor ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Smoke Simulation ◽  
Fire Design

This article aims to simulate fire smoke spread in atrium-corridor structure with different factors, reveal the relation between spread time and each single factor, which may provide guidance for further fire design in the atrium-corridor structure.

Study on the smoke propagation characteristics of metro tunnel fire under the effects of piston wind

2021 ◽  
pp. 1420326X2199842
Author(s):  
Fei Wang ◽  
Fang Liu ◽  
Imad Obadi ◽  
Miaocheng Weng
Keyword(s):  
Wind Speed ◽  
Bernoulli Equation ◽  
Propagation Characteristics ◽  
Control Effect ◽  
Smoke Control ◽  
Tunnel Fire ◽  
Longitudinal Ventilation ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Metro Tunnel

Metro trains running in tunnels cause piston wind, and when a metro train stops in a tunnel due to a fire, the effect of the piston wind on smoke propagation characteristics cannot be ignored. In this paper, a theoretical model based on the unsteady flow theory of the Bernoulli equation was established to describe the change in piston wind speed under fire conditions. The characteristics of the smoke propagation in tunnel fires under the effect of the piston wind were analysed by means of numerical simulation. The result indicates that the piston wind has a significant effect on the characteristics of smoke distribution. In a longitudinally ventilated tunnel, whether the direction of piston wind is the same as that of longitudinal ventilation could seriously affect the control of fire smoke. When the direction is the same, the piston wind could enhance the smoke control effect of the longitudinal ventilation. Otherwise, the smoke control effect could be significantly diminished, and the smoke control by the critical wind speed of longitudinal ventilation would fail. The findings could contribute to a better understanding of the characteristics of tunnel fire to control smoke spread under the influence of piston wind.

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