Influence law of air flow and water immersion duration on the risk of secondary oxidation spontaneous combustion of coal

Abstract To further elucidate the variations of secondary oxidation spontaneous combustion risk of lignite under different air flows and immersion time. Secondary oxidation experiments of short-term water-immersed coal and long-term water-immersed coal were conducted under four air flows. The result...

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Main Authors: Ruirui Yu, Ziwen Dong, Wanting Zhao, Peitao Zhu, Song Kong, Zhenya Zhang
Format: Article
Language:English
Published: Nature Portfolio 2025-01-01
Series:Scientific Reports
Subjects:
Online Access:https://doi.org/10.1038/s41598-024-84345-9
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author Ruirui Yu
Ziwen Dong
Wanting Zhao
Peitao Zhu
Song Kong
Zhenya Zhang
author_facet Ruirui Yu
Ziwen Dong
Wanting Zhao
Peitao Zhu
Song Kong
Zhenya Zhang
author_sort Ruirui Yu
collection DOAJ
description Abstract To further elucidate the variations of secondary oxidation spontaneous combustion risk of lignite under different air flows and immersion time. Secondary oxidation experiments of short-term water-immersed coal and long-term water-immersed coal were conducted under four air flows. The results show that, the presence of a temperature inflection point during primary oxidation process, when coal temperature exceeds it, both the oxygen consumption rate and heat release intensity of long-term water-immersed coal are lower, furthermore, decrease in air flow leads to reduction in the temperature inflection point. The oxygen consumption rate and heat release intensity during the primary oxidation process exceed those observed during the subsequent secondary oxidation process. In the secondary oxidation process, long-term water-immersed coal exhibits higher rates of oxygen consumption and heat release intensity compared to short-term water-immersed coal. Additionally, the oxygen-consuming activation energy for oxygen consumption of long-term water-immersed coal is lower. The increase in air flow and water immersion time generally leads to the extreme value of the limit parameters, such as the local maximum of minimal thickness of residual coal and the lower limit oxygen fraction, the local minimum of the maximal air leakage intensity develops in the direction of increasing the risk of spontaneous combustion of coal in goaf.
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spelling doaj-art-7ed7d831bb4d4dd9a5b83ef297cdabf82025-01-05T12:14:37ZengNature PortfolioScientific Reports2045-23222025-01-0115111510.1038/s41598-024-84345-9Influence law of air flow and water immersion duration on the risk of secondary oxidation spontaneous combustion of coalRuirui Yu0Ziwen Dong1Wanting Zhao2Peitao Zhu3Song Kong4Zhenya Zhang5School of Materials and Chemical Engineering/School of Safety Engineering, Ningbo University of TechnologySchool of Materials and Chemical Engineering/School of Safety Engineering, Ningbo University of TechnologySchool of Materials and Chemical Engineering/School of Safety Engineering, Ningbo University of TechnologySchool of Civil and Transportation Engineering, Ningbo University of TechnologySchool of Materials and Chemical Engineering/School of Safety Engineering, Ningbo University of TechnologySchool of Civil and Transportation Engineering, Ningbo University of TechnologyAbstract To further elucidate the variations of secondary oxidation spontaneous combustion risk of lignite under different air flows and immersion time. Secondary oxidation experiments of short-term water-immersed coal and long-term water-immersed coal were conducted under four air flows. The results show that, the presence of a temperature inflection point during primary oxidation process, when coal temperature exceeds it, both the oxygen consumption rate and heat release intensity of long-term water-immersed coal are lower, furthermore, decrease in air flow leads to reduction in the temperature inflection point. The oxygen consumption rate and heat release intensity during the primary oxidation process exceed those observed during the subsequent secondary oxidation process. In the secondary oxidation process, long-term water-immersed coal exhibits higher rates of oxygen consumption and heat release intensity compared to short-term water-immersed coal. Additionally, the oxygen-consuming activation energy for oxygen consumption of long-term water-immersed coal is lower. The increase in air flow and water immersion time generally leads to the extreme value of the limit parameters, such as the local maximum of minimal thickness of residual coal and the lower limit oxygen fraction, the local minimum of the maximal air leakage intensity develops in the direction of increasing the risk of spontaneous combustion of coal in goaf.https://doi.org/10.1038/s41598-024-84345-9Secondary oxidationOxygen consumption rateOxygen-consuming activation energyLimit parametersSpontaneous combustion hazard
spellingShingle Ruirui Yu
Ziwen Dong
Wanting Zhao
Peitao Zhu
Song Kong
Zhenya Zhang
Influence law of air flow and water immersion duration on the risk of secondary oxidation spontaneous combustion of coal
Scientific Reports
Secondary oxidation
Oxygen consumption rate
Oxygen-consuming activation energy
Limit parameters
Spontaneous combustion hazard
title Influence law of air flow and water immersion duration on the risk of secondary oxidation spontaneous combustion of coal
title_full Influence law of air flow and water immersion duration on the risk of secondary oxidation spontaneous combustion of coal
title_fullStr Influence law of air flow and water immersion duration on the risk of secondary oxidation spontaneous combustion of coal
title_full_unstemmed Influence law of air flow and water immersion duration on the risk of secondary oxidation spontaneous combustion of coal
title_short Influence law of air flow and water immersion duration on the risk of secondary oxidation spontaneous combustion of coal
title_sort influence law of air flow and water immersion duration on the risk of secondary oxidation spontaneous combustion of coal
topic Secondary oxidation
Oxygen consumption rate
Oxygen-consuming activation energy
Limit parameters
Spontaneous combustion hazard
url https://doi.org/10.1038/s41598-024-84345-9
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