Shockwave and dynamic pressure propagation law of methane–air explosion in full-scale pipe network

Abstract

ABSTRACT Methane explosions are the main cause of coal mine disasters. Considering the scale effect involved in the process of methane explosion, small-scale methane explosion experiments can only obtain a qualitative trend of explosion parameters. It is necessary to study methane explosions in a full-size complex pipe network. In this study, the No. 501 experiment at the Lynn Lake Experimental Mine in the United States was used as the background case. GASFLOW-MPI was used to study the oscillation, attenuation, and dynamic pressure evolution laws of the explosion shockwaves in a full-size complex pipe network with consideration of the heat loss. The results showed that the numerical simulation results considering heat loss were more accurate than the adiabatic simulation results, and the average error of the peak pressure was only 4.25%. The pressure – time history curve of methane explosion shockwaves in a complex pipe network differed from that in a single pipe. The pressure peak was a bimodal curve near the explosion source, the dynamic pressure changes significantly, and both forward and reverse wind reaching 200 m/s occurred. The pressure curve far from the explosion source was a unimodal peak curve, and only the forward wind occurred. This reasonably explains the bidirectional deformation of rock bolted plates found in the US UBB accident. The results are expected to provide theoretical support for emergency mine rescue operations and mitigating the effects of methane explosions.