Mechanism research of gas and coal dust explosion

Combined with the experimental results from the large tunnel of the ChongqingResearch Institute,the mechanism of gas and coal dust explosion was studied.Someconcepts about gas and coal dust explosion were introduced such as the form conditionand influential factors.Gas and coal dust explosion propagation was researched and thelifting process of coal dust was simulated.When an explosion occurred due to great mixtureof gas and air,the maximum explosion pressure appeared in the neighborhood of theexplosion source point.Before it propagated to the tunnel of the deposited coal dust,themaximum explosion pressure appeared to be in declining trend.Part of the energy waslost in the process of raising the deposited coal dust through a shock wave,so the maximumexplosion pressure was smallest on the foreside of the deposited coal dust sector.On the deposited coal dust sector,the explosion pressure rapidly increased and droppedoff after achieving the largest peak value.Because of coal dust participation in the explosion,the flame velocity rose rapidly on the deposited coal dust and achieved a basic stablevalue;coal dust was ignited to explode by initial laminar flame,and the laminar flametransformed into turbulent flame.The turbulence transformed the flame fold into a funnelshape and the shock wave interacted with the flame,so the combustion rate rose and thepressure wave was further enhanced.The regeneration mechanism between the flamecombustion rate and the aerodynamic flowing structure achieved the final critical state forforming the detonation.