Study of the destruction of ventilation systems in coal mines due to gas explosions

Abstract

Gas explosions presented a serious safety threat in the mining industry worldwide. Many coal miners had been killed due to explosions in mining. The malfunction of a ventilation system caused by a gas explosion was the primary reason for casualties in coal mines. In this study, two models were built to simulate ventilation systems in which gas explosions often occur. The models consisted of a pipe incorporating weak panels. Using each model, the propagation of the overpressure shock wave and the distribution on the ventilation system were verified. According to the characteristics of multiple ventilation facilities in a local ventilation system, the combined effects of bends and bifurcations and the destruction of ventilation facilities in the local network model due to an overpressure wave were analyzed. By analyzing the distribution of the methane/air mixture explosion overpressure wave in the pipe models, the effect of a weak panel on the explosion shock wave and the degree of explosion damage were characterized by the statistical results from the sizes of the fragments. The explosion wave peak overpressure in the forward direction was higher than the peak overpressure in the elbow bend direction. After explosion, the production gas was immediately extracted and the composition was analyzed. The destruction order for different ventilation facilities in the local ventilation system was determined according to the pipe model experimental results. The disaster of gas explosion for ventilation network and workers was analyzed, and the spare door was designed to recover the ventilation system after gas explosion.