Study on the air leakage characteristics of a goaf in a shallow coal seam and spontaneous combustion prevention and control strategies for residual coal

Jianwei Li; Xintian Li; Changyou Liu; Ningbo Zhang

doi:10.1371/journal.pone.0269822

Study on the air leakage characteristics of a goaf in a shallow coal seam and spontaneous combustion prevention and control strategies for residual coal

PLoS One. 2022 Jun 24;17(6):e0269822. doi: 10.1371/journal.pone.0269822. eCollection 2022.

Authors

Jianwei Li¹, Xintian Li¹, Changyou Liu², Ningbo Zhang²

Affiliations

¹ College of Mining and Coal, Inner Mongolia University of Science and Technology, Baotou, China.
² School of Mines, China University of Mining & Technology, Xuzhou, China.

Abstract

Air leakage from surface mining-induced fissures can easily cause spontaneous combustion of residual coal in the goaf, which threatens the safe production of the underground working face. In order to study the air leakage law of the goaf under the surface air leakage and the prevention and control technology of spontaneous combustion of residual coal. Based on engineering data from the 6104 working face of the Chuancao Gedan coal mine, this study uses a combination of theoretical analyses, numerical simulations, and field observations to study the dynamic distribution characteristics of the air leakage velocity of surface mining-induced fissures in shallow coal seams, the distribution characteristics of relative pressure, the air leakage velocity, the air leakage flow field, the distribution ranges for the "three zones" of spontaneous combustion in the goaf, and a reasonable range for the pressurized ventilation of the working face. The results show that there is a quadratic relationship between the air leakage speed from the surface mining-induced fissures in shallow coal seams and the distance from the working face. The air leakage speed decreases as the distance from the working face increases, and the air leakage speed in the middle of the working face is slower than the air leakage on either side of the goaf. The pressure difference between the goaf and the surface mining-induced fissures is the root cause of air leakage into the goaf, and a change in the pressure difference has a significant impact on the air leakage flow field and the distributions of the "three zones" of spontaneous combustion in the goaf. When the pressure difference between the ground surface and the working face is maintained within the range of 200~-200 Pa, air leakage is effectively reduced, and the spontaneous combustion of residual coal is inhibited. The research results reveal the air leakage mechanism in the goaf of shallow coal seams and provide a reference for the prevention and control of spontaneous combustion of residual coal in the goaf.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Coal
Coal Mining* / methods
Engineering
Pressure
Spontaneous Combustion*

Substances

Coal

Grants and funding

Thanks to the National Natural Science Foundation of China, grant number 51864036, the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region, grant number NJYT-19-B33 and the Program for young innovative talents of “Grassland Talents” of Inner Mongolia for providing financial support to the author Jianwei Li. The authors would like to express their sincere gratitude for this financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.