Study On Power Transmission Law Of Coal And Gas Outburst In Mine Ventilation System

In order to study the gas dynamic effects on mine ventilation system,aerodynamics-related knowledge,transient flow thery,incompressible thery,convection-diffusion and source-containing ventilation network is combined to analyze the diffusion of the outburst gas.An unsteady similar experimental is designed to verifie that the use of incompressible thery in the simulation of final phase of outburst is reasonable and accurate.According to the aforesaid theory and methods,disaster ventilation simulation software has been developed.This software not only can be used for normal mine ventilation simulation,which can also be used for disaster ventilation simulation after a gas outburst.This software can simulate gas diffusion process in whole mine and the changs of air volume of roadways,at a given pressure or flow boundary conditions;can simulate the spread pressure and wind speed variations cloud of the whole mine after a gas outburst,at a given pressure boundary condition.The simulation of Jiaozuo Jiulishan mine“10·27”outburst is used to verify the reliability of research results.Researches indicate:Outburst pressure wave and blast wave is quite different;Shock wave velocity is greater than the local speed of sound.Pressure wave propagation velocity is the speed of sound.Gas migration velocity is less than the pressure wave velocity;After the outburst,the propagation of pressure wave in whole mine is the first reasons which lead the change of flow;The effects of gas outburst on mine ventilation system include direct power influence and gas ventilation pressure.The use of incompressible thery and source-containing ventilation network thery to simulate the gas diffusion in the whole mine,taking into account two effects,is science.The use of the traditional network theory to simulate this disaster process,only consider the effect of gas pressure on the ventilation system,which is a great error or even wrong in early of the final phase;Gas outburst when occurred on the rise road,may lead to reduced air flow or even reverse in the side branch;when occurred on the downhill roadway,the air flow may stagnate even reverse back;Outburst will increase the air volume in air-return shaft,reduce air flow volume in the air-intake shaft,and even turn the a air-intake shaft into a air-return shaft.The research results have important theoretical and practical significance for outburst disaster aid,as well as effectively preventing the occurrence of secondary disasters.