Study On The Influence Of Spontaneous Combustion Induced By The Drainage Negative Pressure In Goaf

In recent years,gas drainage has become a major means of prevention gas accidents in goaf.However,the drainage negative pressure affected the gas flow and concentration field,which influences the problem of goaf coal spontaneous combustion.Therefore,the study of the rule under the condition of drainage is of great importance for safety mining.Comprehensive analysis of application and research status at home and abroad and the existing researches of mechanisms of coal spontaneous combustion and theories of gas drainage in goaf,the rule of spontaneous combustion in goaf under different drainage negative pressures by buried pipes in 5877 Y working face of Lvjiatuo Mine is studied through laboratory experiment,beam tube monitoring and numerical simulation.Based on the theoretical analysis of fluid mechanics,heat transfer and mass transfer,the mathematical model of multiphysics coupling of spontaneous combustion in goaf is established.Through experiments of industry analysis and comprehensive thermal analysis,parameters like moisture content,density and exothermicity are measured to provide reference for later numerical simulation.By laying tubes in 5877 Y workin g face and monitoring oxygen concentration during mining,the scope of spontaneous combustion “three zones” is defined.By the goaf spontaneous combustion mathematical model and the COMSOL calculating,distributions of flow field,temperature field and the oxygen concentration field,the spontaneous combustion “three zones” and the danger zone of high temperature under different drainage negative pressures are obtained.The comparison between measured and simulated result proves the rationality of the mode l.The rule of goaf spontaneous combustion in different drainage negative pressures is got by numerical simulation,which accurately predicts the “three zones” and the danger zone under different drainage negative pressure.It is of great practical signifi cance for the prevention and control of fire caused by spontaneous combustion under drainage in goaf.