A Study on Ceiling Temperature Distribution and Critical Exhaust Volumetric Flow Rate in a Long-Distance Subway Tunnel Fire with a Two-Point Extraction Ventilation System

Zhao, Peng; Yuan, Zhongyuan; Yuan, Yanping; Yu, Nanyang; Yu, Tao

doi:10.3390/en12081411

Cited by 17 publications

(5 citation statements)

References 28 publications

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“…The point smoke exhaust system can effectively achieve the separation of smoke and people, and has become the first choice for smoke control design in many traffic tunnels [4]. At present, domestic and foreign studies on tunnel fires are mainly on horizontal and single-slope tunnels [5][6][7][8][9][10][11], and there are also related studies on V-shaped tunnels, such as Xuepeng Jiang [12] and En Xie [13] on the free diffusion law of smoke and smoke back-layering length of V-shaped slopes. But there is a lack of research on the effect of point smoke exhaust in V-shaped tunnels.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study on the Efficiency of the Point Smoke Exhaust System in V-shaped Urban Underground Road Tunnel

Kang,

Li,

Qiao

et al. 2024

J. Phys.: Conf. Ser.

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In order to study the exhaust effect of the point smoke exhaust system in V-shaped urban underground tunnel with different structures, effects of the slope differences on both sides of the slope changing point and the operating mode of the exhaust vent on the smoke spread distance, temperature at the height of 2 m above the road and the ceiling temperature were studied by the numerical method. The research results show that for the symmetric V-shaped tunnel, smoke can be controlled in the required range, but for asymmetric V-shaped tunnel with the slope difference on both sides, smoke cannot be easily controlled, ventilation supply is needed to improve the smoke exhaust efficiency. Point smoke exhaust system cannot effectively reduce the maximum temperature of the ceiling above the fire. When the fire source power is large, for the symmetrical V-shaped tunnel with a small slope, some fire prevention measures must be taken to protect the ceiling partition. For the asymmetric V-shaped tunnel, two exhaust vents opened on the small slope side and four opened on the large slope side are suggested for the occupant safe evacuation in tunnel.

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Section: Introductionmentioning

confidence: 99%

Numerical Study on the Efficiency of the Point Smoke Exhaust System in V-shaped Urban Underground Road Tunnel

Kang,

Li,

Qiao

et al. 2024

J. Phys.: Conf. Ser.

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“…Research on the application of point exhaust ventilation in tunnel fire smoke control has been reported extensively. Zhao et al [11] analyzed the critical smoke exhaust rate and temperature distribution in two-point exhaust tunnels through a 1:20 model test combined with theoretical analysis and obtained the corresponding prediction model. Tang et al [12] studied the effect of the longitudinal velocity on maximum temperature and found out a calculation model of maximum temperature in a smoke exhaust tunnel.…”

Section: Introductionmentioning

confidence: 99%

Effect of Different Smoke Vent Layouts on Smoke and Temperature Distribution in Single-Side Multi-Point Exhaust Tunnel Fires: A Case Study

Tao

Zeng

2022

Fire

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In this paper, a numerical model verified by a 1:10 small-scale model test was used to study the effect of different smoke vent layouts on fire characteristics and smoke exhaust efficiency. The results show that the total smoke spread length is shortest when four smoke vents are opened near the fire source. If there are more than four smoke vents, some of them will only inhale fresh air rather than smoke. More seriously, some smoke vents will promote the spread of toxic smoke farther. Under different smoke vent layout schemes, the maximum temperature shows the same change trend with the increase in smoke exhaust volume (first increasing and then decreasing). When there are four smoke vents, the temperature field is in a good range compared with other schemes. If four smoke vents are opened, the total smoke exhaust efficiency is highest, and exhaust rate has little influence on total exhaust efficiency. Total smoke exhaust efficiency of the tunnel is more than 93.7% under different exhaust volumes, and the maximum difference of total smoke exhaust efficiency is less than 1.5% under different exhaust volume of Case “4”. The exhaust volume has little influence on temperature decay beneath the ceiling, and a temperature attenuation model of a point exhaust tunnel with four smoke vents was proposed. For the single-side point exhaust tunnels, the number of smoke vents near the exhaust fan side shall not be more than that on the other side. Four smoke vents shall be opened in case of fire and the exhaust volume is 220 m³/s with HRR of 30 MW.

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“…The complex buildings in the URT system, ranging from station, section, vehicle base, to control center, belong to varied fire resistance ratings. Their components must meet relevant national standards [13][14][15][16][17][18][19]. To safeguard people's lives and properties, it is important to study the fire propagation law in large modern URT buildings.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation and Thermophysical Feature Analysis of Fire Propagation Law in Large Urban Rail Transit Buildings

Duanmu¹,

Zhan²,

Song³

2021

IJHT

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As the development of urban rail transit (URT) picks up speed, more and more attention has been paid to the safety hazards that threaten URT operations. In URT buildings with different fire resistance ratings, the combustion performance and fire resistance limit of their components must meet relevant national standards. It is of certain practical significance to explore the fire propagation law in large modern URT buildings. Considering the peculiarity of URT building fire, this paper carries out numerical simulation and thermophysical feature analysis of fire propagation law. Firstly, the fire propagation features in underground station and section (USS) of URT system were described, and the corresponding control equations were established for mass, momentum, and energy. Then, the factors affecting the attenuation coefficient, including heat exchange coefficient, convection coefficient, and radiation coefficient, were analyzed, and a prediction model was established for temperature attenuation. Experiments were carried out to verify the scientific nature of our numerical simulation of fire propagation law in URT buildings, and obtain the thermophysical properties of fire propagation in URT buildings.

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A Study on Ceiling Temperature Distribution and Critical Exhaust Volumetric Flow Rate in a Long-Distance Subway Tunnel Fire with a Two-Point Extraction Ventilation System

Cited by 17 publications

References 28 publications

Numerical Study on the Efficiency of the Point Smoke Exhaust System in V-shaped Urban Underground Road Tunnel

Numerical Study on the Efficiency of the Point Smoke Exhaust System in V-shaped Urban Underground Road Tunnel

Effect of Different Smoke Vent Layouts on Smoke and Temperature Distribution in Single-Side Multi-Point Exhaust Tunnel Fires: A Case Study

Numerical Simulation and Thermophysical Feature Analysis of Fire Propagation Law in Large Urban Rail Transit Buildings

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