Study On The Propagation Law And Influence Factors Of Gas Explosion Shock Wave In The Underground Roadway

Most coal containing in our country holds gas to varying degree, which causesgas explosion to be one of the biggest hidden troubles of security in the coal mining.Since the founding of new China, coal mine safety accidents occurred frequently,especially the gas explosion resulting in the huge property losses and casualtiesthreatened the development of coal industry in China. Therefore, researches onunderground roadway gas explosion characteristics and influencing factors of gasexplosion is of great significance.Based on the gas thermal explosion theory and the theory of fluid dynamics,this thesis analysis the influence of the factors such as the gas concentration, theobstacles and pipeline of the structure to the characteristics of gas explosionpropagation. According to the theory of gas explosion shock wave propagationanalysis, this thesis established a suitable physical and mathematical model, usingdisplay dynamic analysis software LS-DYNA to simulate the process of roadway ingas explosion shock wave propagation. According to the feature of LS-DYNAsoftware, the author regards the spread of gas explosion in the roadway as afluid-structure interaction problems. Combined with complicated environmentunderground roadway, in this paper, the simplified roadway turning roadwaycross-sectional area changes, roadway bifurcation, and setting up obstacles ofroadway model is simulated, and several kinds of models in different location ofroadway under explosion pressure and the flow field changes are analyzed.According to theoretical analysis and numerical simulation, this thesis get thefollowing conclusion: The barrier in tunnel has incentive effect obviously on the gas explosionpropagation. The formation of gas explosion near the obstacles is high, the barrierdue to the block and the diffraction effect to form the gas explosion low pressurearea, the presence of obstacles slowing the attenuation of gas explosion; A bend inthe tunnel, when the gas explosion propagates to the corner, it will form a highpressure zone on the upper wall, while the bottom wall form the low pressure area,and the pressure of bend and bend feature point explosion roadway is obviouslyhigher than that of straight roadway; bifurcation of roadway has obvious dischargeeffect on gas explosion pressure, bifurcated tunnel in feature point pressure issignificantly lower than straight feature point pressure in the roadway; the suddenexpansion of roadway cross-sectional area can accelerate the speed of explosionshock wave and reduce the pressure of gas explosion, on the contrary, the suddennarrowing cross section area of roadway can reduce the speed of shock wavepropagation and increase the pressure of gas explosion.Based on the findings of the research, the author puts forward the measures andmethods to reducing harm gas explosion, hoping to provide certain theoreticalguidance for coal mine safety production.