Experimental Study on Spontaneous Combustion Monitoring in Coal Mine Airspace Based on Distributed Fiber Optic Temperature Measurement

ABSTRACT

Spontaneous combustion fires in the mining airspace seriously affect safety at mines. It is crucial to accurately predict the location of fire sources and forecast spontaneous combustion disasters. This study, therefore, proposes an intuitive, accurate, and efficient distributed fiber optic temperature measurement technique for detecting spontaneous coal combustion. To overcome the limitations of using traditional optical fibers in the complex environment of the goaf, this study independently developed an enhanced armored distributed optical fiber for coal mines through experiments. Aiming at the possible influence of the armoring material on the accuracy of temperature measurement, the temperature of the armored distributed optical fiber was corrected through calibration experiments of the armored optical fiber and the heat transfer simulation study of the enhanced temperature measurement optical fiber, to improve the accuracy of the measurement. Based on COMSOL’s simulation study of the spontaneous combustion temperature field and fiber optic detection in the extraction zone, a method of laying optical fibers in parallel at 15-meter intervals to achieve accurate detection of the fire source location in the extraction zone. To explore the feasibility of this technology, a field test was carried out in the 22,117 working faces of Shanxi Lu’an Group Luning Coal Co. Ltd. in the hollow area. The temperature analysis results are consistent with the results of the beam pipe monitoring. The results show that the distributed fiber optic temperature measurement technology can produce a graded warning of spontaneous coal combustion and achieve an accurate detection of the fire source.

KEYWORDS:

• Distributed fiber optics
• goaf
• spontaneous coal combustion
• predictive forecasting
• numerical simulation

Acknowledgements

The author thanks National Natural Science Foundation of China (52074188) Graduate Education Innovation Project Fund of Shanxi Province (2023KY182) Supported by Fundamental Research Program of Shanxi Province (202203021212218) Research on Intelligent Monitoring Technology of Coal Mine Airspace Temperature Information Based on Distributed Fiber Optics (023AH504064B) Research on the coupled pollution of H₂S and dust in high sulfur mines and synergistic control mechanism(202203021212218).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [52074188].