Effect of flexible obstacles on gas explosion characteristic in underground coal mine

Abstract

Gas explosion is one of the fatal accidents in underground coal mine, threatening the lives of miners and causing significant economic losses. Gas explosion characteristics are affected by many factors, including flexible obstacles such as flexible duct systems (DS) and line brattices (LB) in the auxiliary ventilation system. In order to explore the influence of flexible obstacles in the tunnel on the propagation law of gas explosion, this study established a numerical simulation model by using OpenFOAM that is an open-source CFD source code. The process variable in XiFoam tools was used for deflagration reaction. Gas explosion simulations were carried out for analyzing the impacts of DS and LB on the evolution of flame and shock wave propagation inside the tube. The results showed that the effect of flexible obstacles on the flame propagation law was evident. The flame shape easily caused many wrinkles in the tube with flexible obstacles. Meanwhile, the maximum pressure and flame propagation speed changed obviously comparing with the empty tube. In the model of DS and LB, the maximum pressure increased by 29 % and 77.8 % than the maximum pressure of empty tube, and the maximum flame propagation speed increased by 6.8 % and 20 % than the flame propagation of empty tube, respectively. The results can provide guidance for gas explosion prevention in underground coal mine.