Application of a Simulation Method for the Shock Wave Propagation Law of Gas Explosion

Gas explosion is one of the main causes of casualties in coal mines. Studying the propagation law of shock wave of mine gas explosion can reduce the economic loss and personnel injury caused by mine gas explosion. To solve the difficulty in the research of shock wave propagation of gas explosion in the mine scale, the segmented relay simulation method of shock wave propagation of gas explosion in a coal mine was put forward, the related key problems were studied, and the results were successfully applied in Yangchangwan No. 2 Mine. The results show the following: (1) When the length of the forked roadway exceeds 50 m, the length of the forked roadway has little effect on the shock wave overpressure in the main roadway. When the length of the forked roadway is short, the closure of the forked roadway has a great influence on the change curve of the shock wave overpressure in the main roadway. Therefore, the length of the bifurcation roadway should not be less than 50 m in numerical simulation. (2) The angle of the bifurcated roadway has a great influence on the shock wave propagation of explosion in the main roadway. With the increase in the angle of the bifurcated roadway, the overpressure in the main roadway tends to increase at first and then decrease, and the peak overpressure is the highest when the angle of the bifurcated roadway is 90°. (3) The influence range of the roadway pressure-outlet boundary is about 5 m, and the dynamic parameter monitoring point should be set at about 10 m away from the pressure outlet; dynamic boundary monitoring parameters should include static pressure, dynamic pressure, and temperature. (4) When the gas explosion occurs in the heading face, the shock wave will cause great damage to the adjacent heading face. When the shock wave reaches the head-on and upper corner of the heading face, it will be reflected violently, which will cause the local overpressure to rise obviously. The peak overpressure and gas accumulation length conform to the logarithmic function.