The Influence of Different Concentrations of Methane in Ditches on the Propagation Characteristics of Explosions

As the urban underground natural gas pipeline network expands, the explosion risk arising from methane accumulation in drainage ditches due to pipeline leakage has increased severely. A two-dimensional numerical model—9.7 m in length (including a 1-m obstacle section), 0.1 m in diameter, and with a...

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Main Authors: Xingxing Liang, Junjie Cheng, Yibo Zhang, Zhongqi Wang
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Fire
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Online Access:https://www.mdpi.com/2571-6255/8/7/275
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author Xingxing Liang
Junjie Cheng
Yibo Zhang
Zhongqi Wang
author_facet Xingxing Liang
Junjie Cheng
Yibo Zhang
Zhongqi Wang
author_sort Xingxing Liang
collection DOAJ
description As the urban underground natural gas pipeline network expands, the explosion risk arising from methane accumulation in drainage ditches due to pipeline leakage has increased severely. A two-dimensional numerical model—9.7 m in length (including a 1-m obstacle section), 0.1 m in diameter, and with a water volume fraction of 0.2—was developed to address the flexible boundary characteristics of urban underground ditches. The investigation examined the influence of methane concentration on explosion propagation characteristics. Results indicated that, at a methane concentration of 11%, the peak pressure attained 157.9 kPa, and the peak temperature exceeded 3100 K—all of which were significantly higher than the corresponding values at 10%, 13%, and 16% concentrations. Explosion-induced water motion exerted a cooling effect that inhibited heat and pressure transfer, while obstacles imposed partial restrictions on flame propagation. Temporal profiles of temperature and pressure exhibited three distinct stages: “initial stability–rapid rise–attenuation”. Notably, at a methane concentration of 16%, the water column formed by fluid vibration demonstrated a pronounced cooling effect, causing faster decreases in measured temperatures and pressures compared to other concentrations.
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institution Kabale University
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publishDate 2025-07-01
publisher MDPI AG
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series Fire
spelling doaj-art-bd1d99d3b7d84cef999c9ea83642cfe92025-08-20T03:58:26ZengMDPI AGFire2571-62552025-07-018727510.3390/fire8070275The Influence of Different Concentrations of Methane in Ditches on the Propagation Characteristics of ExplosionsXingxing Liang0Junjie Cheng1Yibo Zhang2Zhongqi Wang3Faculty of Public Security and Emergency Management, Kunming University of Science and Technology, Kunming 650500, ChinaFaculty of Public Security and Emergency Management, Kunming University of Science and Technology, Kunming 650500, ChinaFaculty of Public Security and Emergency Management, Kunming University of Science and Technology, Kunming 650500, ChinaState Key Laboratory of Explosion Science and Safety Protection, Beijing Institute of Technology, Beijing 100081, ChinaAs the urban underground natural gas pipeline network expands, the explosion risk arising from methane accumulation in drainage ditches due to pipeline leakage has increased severely. A two-dimensional numerical model—9.7 m in length (including a 1-m obstacle section), 0.1 m in diameter, and with a water volume fraction of 0.2—was developed to address the flexible boundary characteristics of urban underground ditches. The investigation examined the influence of methane concentration on explosion propagation characteristics. Results indicated that, at a methane concentration of 11%, the peak pressure attained 157.9 kPa, and the peak temperature exceeded 3100 K—all of which were significantly higher than the corresponding values at 10%, 13%, and 16% concentrations. Explosion-induced water motion exerted a cooling effect that inhibited heat and pressure transfer, while obstacles imposed partial restrictions on flame propagation. Temporal profiles of temperature and pressure exhibited three distinct stages: “initial stability–rapid rise–attenuation”. Notably, at a methane concentration of 16%, the water column formed by fluid vibration demonstrated a pronounced cooling effect, causing faster decreases in measured temperatures and pressures compared to other concentrations.https://www.mdpi.com/2571-6255/8/7/275methane explosionurban underground ditchnumerical simulationconfined space explosion dynamicsgas–liquid two-phase flow
spellingShingle Xingxing Liang
Junjie Cheng
Yibo Zhang
Zhongqi Wang
The Influence of Different Concentrations of Methane in Ditches on the Propagation Characteristics of Explosions
Fire
methane explosion
urban underground ditch
numerical simulation
confined space explosion dynamics
gas–liquid two-phase flow
title The Influence of Different Concentrations of Methane in Ditches on the Propagation Characteristics of Explosions
title_full The Influence of Different Concentrations of Methane in Ditches on the Propagation Characteristics of Explosions
title_fullStr The Influence of Different Concentrations of Methane in Ditches on the Propagation Characteristics of Explosions
title_full_unstemmed The Influence of Different Concentrations of Methane in Ditches on the Propagation Characteristics of Explosions
title_short The Influence of Different Concentrations of Methane in Ditches on the Propagation Characteristics of Explosions
title_sort influence of different concentrations of methane in ditches on the propagation characteristics of explosions
topic methane explosion
urban underground ditch
numerical simulation
confined space explosion dynamics
gas–liquid two-phase flow
url https://www.mdpi.com/2571-6255/8/7/275
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