Numerical Simulation Analysis Of Seepage-gushing Characteristics In Front Of The Coal Mining Work Face

It is a very complex problem of coal seam gas occurrence and flow. At present,the research to the theory of gas flow has been more perfect. But in the actual coalmining process, the physical environment of coal is very complex, which makes theanalysis of gas flow state hard. Therefore, in this paper, based on the coal parameterthrough the laboratory test, some related functions of ANSYS finite element softwareare used to simulate the gas seepage field, and discuses the gas pressure distributioncharacteristics in coal seam and the seepage properties characteristics under theinfluence of gas pressure and mining stress.Using related functions of ANSYS finite element software, the numericalanalysis of the seepage flow field and mining stress field on the seam is takensystematically. contrasting the thermal analysis principle of ANSYS finite elementsoftware and gas seepage control equation, the feasibility of gas seepage simulation isdetermined, and by derivate unit of the equation, the material parameters unitrequired by the finite element analysis is determined, which makes the parametersand boundary conditions, used in the analysis, meet the coal seam gas seepage theory.by getting the gas pressure-permeability relation curve through the empirical formula,and taking it into the nonlinear calculation by parameters nonlinear definitionfunction, the seepage field and pressure field under the influence of gas pressure iscalculated out, and contrasting with them without influence, the effect characteristicsof gas pressure to the seepage field are concluded; with the simulation of mining areacoal mining stress field, coal swelling rate, and the relationship between the effectivestress and the permeability, the coal seam permeability distribution is determined, andthe seepage simulation is taken out with it.It is apparent by the simulation results that, gas pressure and mining stress iseffective on gas seepage, and can reduce the gas pressure in coal body near workingsurface. The analysis to gas flow velocity of the working face obtains gas emissionrate and emission quantity. But in the early coal exposure, due to uneven distributionof mining coal stress, coal body swelling and unloading, permeability changesirregularly, which results unstable seepage in the coal body, and effects of gaspressure and mining stress on coal and gas outburst are analyzed.Through the establishment of simulate model and data parameters more in linewith the actual coal mining, a series of gas seepage numerical simulation can be takengenerally. It also provides a new method to analyze gas seepage in coal seam.