Equilibrium Point For The Method Of Dealing With Both Gas And Fire In High Gas Spontaneous Combustion Coal Seam Fully-Mechanized Mine Goaf

For the Ting Nan Coal Mine 206 high gas spontaneous combustion coal seam fully mechanized mine goaf facing the problem that there are more coals left in the goaf which provided more sources of gas emission,methods of increasing gas extraction is used.On the other hand,the possibility of spontaneous combustion of coal seam will become larger.This thesis establishes the empirical model of porosity distribution in fully mechanized mine goaf.The CFD method is used to solve the three-dimensional flow field to obtain the spatial distribution of gas,air leakage and oxygen in the goaf.The spontaneous combustion"three zones" multi-index coupling dividing method which using the 0.004m/s upper limit air leakage velocity and the 10%lower limit oxygen volume fraction is proposed.The thesis puts forward that the minimum floating coal thickness of 0.6?3.0m can be used as the spontaneous combustion zone in the mine goaf.Aiming at the problem of multi factors and multi levels equilibrium point,statistical thinking is introduced.The maximum width of the oxidation zone is taken as the test index.Air volume,gas drainage quantity and nitrogen injection are taken as the experimental factors.A remarkable equation is established by using the Box-Behnken quadratic response surface design method.The P value is 0.0095.The final equilibrium point:air supply amount is 1168.10m3/min,extraction quantity is 162.94m3/min,nitrogen injection is 800.01m3/h,maximum width of oxidation zone is 70.37m,and limit advance speed is 1.81m/d.The research results can be used to dealing with both gas and fire for the 206 high gas spontaneous combustion coal seam fully mechanized mine goaf and the similar conditions.