Abstract
Spontaneous combustion of coal occurs when arising from a combination of factors, including oxidation and heating of residual coal in goaf and favorable heat retention conditions, and the spontaneous combustion hazard zones and high-temperature points formed exhibit dynamic, concealed, and three-dimensional characteristics, further complicating the on-site prevention and control of coal spontaneous combustion. Therefore, it is particularly important to study the dynamic evolution of coal spontaneous combustion (CSC) hazard areas in the goaf during the working face advancement process. With 010803 working face of Wang Wa Coal Mine for reference, the paper develops a three-dimensional Multiphysics coupling model of the goaf through field tests, laboratory experiments, and numerical simulations. For the first time, three-dimensional dynamic mesh technology is employed to investigate the spatial dynamic variation laws of spontaneous combustion hazard zones in goaf areas under advancing speeds ranging from 2 to 8 m/day. The results indicate that the relative error between simulated leakage airflow and field measurements is 1.4 %. As the advancing speed of the working face increases, the oxidation zone in the goaf shifts deeper, and its area increases linearly, though the rate of increase gradually decreases. With higher advancing speeds, the temperature of the high-temperature points in the goaf decreases, and the distances of these points from the lower corner of the working face grow exponentially in both strike and dip directions. However, the high-temperature points remain within the oxidation zone, with their strike migration ranging from 86.3 to 149 m and dip migration from 44 to 51 m. Based on this analysis, a spatial distribution function for high-temperature points in goaf areas is proposed. This study provides theoretical support for preventing and controlling coal spontaneous combustion in goaf areas.
Published Version
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