Research On Mixed Gas Explosion And Shock Wave Propagation Characteristics

In our country Mining geological conditions of coal resources is harsh and complex,thatresult gas explosion accident frequency, But there are different types on shock wavepropagation characteristics at different types of tunnels.Usually underground gas containsflammable gas such as hydrogen, carbon monoxide, that have more serious consequences forgas explosion accident and can cause worse personal casualty and property loss.Based on the gas explosion theory, adopting methods of theoretical analysis andnumerical simulation, the dissertation studies characteristics of gas explosion and thepropagation law of shock wave of coal gas explosion in straight tunnel, bifurcation tunnel,and lane-way corner. And studies the over-pressure and dynamic pressure variationcharacteristics of under different hydrogen content in mixed gas explosion in the branchroadway. At last analysis of the explosion shock flame and wave velocity. The results offerimportant theoretical and technological support for preventing and controlling the damage ofexplosion shock wave and decision-making in gas explosion accidents.First hot explosion theory and chain reaction were used in theoretical analysis of the gasexplosion mechanism. Then based on physical mechanism of gas explosion dissemination, theanalysis for regulation of the gas explosion flame dissemination and shock wave spreadingwas made. And from the basic equation of gas explosion,the relationship to the ignitionenergy between shock wave pressure and flame temperature of gas explosion was studied.This paper studies the propagation characteristics of gas explosion shock wave indifferent types of tunnels using AutoReaGas. The results show that Gas explosion shock waveoccur reflection and diffraction, which cause the over-pressure in bifurcation duct andlane-way corner both increases greatly, And the spread of flame propagation speed also growth more quickly. In the bifurcation of the pipeline the combustion process and turbulenceare relatively complex, To bend and bifurcation pipe the over-pressure of lane-way corner isbigger than bifurcation duct greater than straight pipe. Explosion wave reflection will makethe pressure increase markedly.Forward shock wave forms of re-circulation zone throughmultiple reflections. Therefore, the corner of the over-pressure obviously is much greater thanthe other location.In practical mines often exist bifurcation, corner and hydrogen, therefore, in this paper,We studied the different hydrogen ratio of gas explosion shock wave propagationcharacteristics occurred in the branch roadway by numerical simulation The results show thatwith the more increase of hydrogen content,the more fierce of explosion, the more rapid ofover-pressure and dynamic pressure, the higher speed of flame and shock wave speed, thatmade flame structure became distortion and the degree of turbulence became more stronger.When the hydrogen content is higher, detonation phenomenon will happen.Through the simulation of gas explosion shock wave propagation in different types oftunnels and the different proportions of methane-hydrogen mixing process of gas explosionin the branch tunnels. It is concluded that the pressure distribution condition, the change ruleof the measuring point peak over-pressure and dynamic pressure, flame and shock wavepropagation law. Some of the conclusions which this article got have important guidingsignificance on the effective prevention of the gas explosion accidents and the accidentsinvestigation in coal mine.