Reduced-scale experimental and numerical study of fire in a hybrid ventilation system in a large underground subway depot with superstructures under fire scenario

Wang, Zhilei; Zhu, Ling; Guo, Xinxin; Pan, Xuhai; Zhou, Bin; Yang, Jingbin; Jiang, Juncheng; Hua, Min; Feng, Lu

doi:10.1016/j.tust.2019.02.006

Cited by 23 publications

(6 citation statements)

References 28 publications

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“…According to the studies in the literatures, the value of D   should be 4 ~ 16 (Shafee and Yozgatligil, 2018;Wang et al, 2019). Therefore, the mesh size of  is in the range of 0.11 m ~ 0.54 m. Then, the mesh size is set to be 0.125 m near the fire source (8 m from the fire center in both the downhill direction and uphill direction), and 0.25 m in other places as shown in Fig.…”

Section: The Grid Systemmentioning

confidence: 99%

Numerical simulation on the maximum temperature and smoke back-layering length in a tilted tunnel under natural ventilation

Zhang

Lin

Shi

et al. 2021

Tunnelling and Underground Space Technology

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The present study investigates the maximum temperature and smoke back-layering length S in the downhill direction from the fire source in a tilted tunnel under natural ventilation. Numerical simulations were conducted using FDS to study the smoke flow behaviors for a fire in a tunnel with nine tunnel slopes of 0, 1%, 2%, 3%, 4%, 5%, 6%, 7% and 8%. It was found that, due to the stack effect, the smoke stagnated at a distance from the fire source in the downhill direction. The effects of tunnel slope,  , fire source heat release rate, Q , source-ceiling height H and tunnel width W on the maximum temperature and smoke back-layering length were studied. Results showed that the maximum temperature under the ceiling decreased with the increasing of tunnel slope or the decreasing of tunnel width. However, it increased with the increasing of heat release rate or the decreasing of source-ceiling height. A model was proposed for the maximum temperature rise. The smoke back-layering length S decreased with the increasing of the tunnel slope. Fire source heat release rate and tunnel width had no significant effect on the smoke back-layering length. And the smoke back-layering length decreased with the decreasing of source-ceiling height. Based on dimensional analysis, a simple model including the effects of both the tunnel slope and source-ceiling height H, was proposed to predict the smoke back-layering length.

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Section: The Grid Systemmentioning

confidence: 99%

Numerical simulation on the maximum temperature and smoke back-layering length in a tilted tunnel under natural ventilation

Zhang

Lin

Shi

et al. 2021

Tunnelling and Underground Space Technology

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“…Let g0 be the initial boundary value of the hot flue gas flow; q be the horizontal propagation speed of hot flue gas flow. Then, the following can be derived from formula (11):…”

Section: Basic Control Equationsmentioning

confidence: 99%

“…As the passenger traffic of the URT grows annually, the safety of the URT system has attracted more and more attention. Fire is the leading hidden hazard that threatens the operational safety of the URT [7][8][9][10][11][12]. The complex buildings in the URT system, ranging from station, section, vehicle base, to control center, belong to varied fire resistance ratings.…”

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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“…Hu et al [7] pointed out as well that activating the smoke control system too early would have a malign effect on smoke extraction. In order to ensure the safety and reliability of underground subway ventilation system, Wang et al [8] simulated and recorded the height of smoke layer, air flux of shaft, and smoke movement route. It was found that smoke diffusion along the ground floor ceiling could be suppressed by outdoor air flowing into the exhaust fan and smoke did not accumulate in the mezzanine.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Smoke Control in Underground Space

Yao

Zhang³

et al. 2022

Mathematical Problems in Engineering

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As the underground space is relatively closed compared to other buildings, the space is hardly connected to the outside world through entrances and exits, which makes it difficult to ventilate and exchange heat with the outside. In this case, it is easy to cause a large number of casualties when a fire breaks out. When the fire happens smoke will be discharged merely by the mechanical exhaust, and air system should work simultaneously to replenish the oxygen inside. By setting four-group models, the paper analyzes the strategies for smoke extraction and air makeup in the underground construction. The paper points out that when the fire happens in a smoke bay, the neighborhood smoke extraction fan should be opened and the air makeup system should not be located at the top to disturb the smoke layer. By comparing and analyzing the performance of the smoke extraction and air conditioning system, the casualties caused by the high temperature toxic smoke from the fire can be reduced as far as possible.

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Reduced-scale experimental and numerical study of fire in a hybrid ventilation system in a large underground subway depot with superstructures under fire scenario

Cited by 23 publications

References 28 publications

Numerical simulation on the maximum temperature and smoke back-layering length in a tilted tunnel under natural ventilation

Numerical simulation on the maximum temperature and smoke back-layering length in a tilted tunnel under natural ventilation

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

Numerical Simulation of Smoke Control in Underground Space

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