Investigation on coal spontaneous combustion in the gob of Y type ventialtion caving face: A case study

Abstract Gas and coal spontaneous combustion (CSC) compound disasters have become a common mode of serious accidents in coal mines. This study is aimed at revealing the characteristics of such compound disasters in the gob of Y-type ventilation fully mechanized top coal caving face with a high-level drainage roadway (HLDR) (hereafter referred to as “Y+HLDR” working face) and providing a theoretical basis for disaster prevention and control. With the W1310 fully mechanized working face of Gaohe Coal Mine taken as the research background, the distribution law of gas concentration field in the gob of the “Y+HLDR” ventilation mode under different air supply conditions was numerically simulated with the aid of COMSOL, and the area of gas and CSC compound disaster in the gob was divided quantitatively. The results show that data obtained from the field experiment coincide with the simulation results, which verifies the effectiveness of the simulation; Meanwhile, with the increase of air supply volume, the gas concentration near the working face is significantly reduced, and high-concentration gas is transferred to the deep part of the gob. The area where CSC induces gas explosions is divided by superimposing the gas and oxygen concentration fields that meet the conditions of compound disaster occurrence on the gob floor. It is concluded that the range of area with compound disaster risk is positively correlated with the air supply volume. The results of the simulation provide important theoretical guidance for the prevention and control of gob disasters.