Study On Gas Migration Rule In Mining-induced Fractures Field And Application In Project In Yu Wu Coal Mine

Mined crack gas flow field is the basis for deep mining of coal and gas. In this paper, using WYS-800 computer controlled servo triaxial gas seepage)the test apparatus and made experiments of gas and mechanical properties of coal gas seepage. By simplifying the actual crack belt, he constructed mining landings model fractured field, mathematical models construction using the momentum equation, continuity equation, etc., using FLUENT simulation software, the U-shaped U-ventilation systems and ventilation + high pumping Lane crack belt in gas migration law were simulated, verifying by Yu Wu Coal S2107 Face measurement.Conventional triaxial the stress- strain seepage, divided under different gas pressures and different confining pressures of these two conditions. Conventional triaxial stress- strain is divided into four stages: compaction phase, elastic stage, the yield phase and destruction phase. Loading and unloading stress- strain divided into three stages: stress loading phase, phase constant stress and the stress descent phase. Under conditions of constant confining pressure, the compressive strength of coal will bec ome larger as the gas pressure decreases, coal permeability does not change with gas pressure presenting certain law. Under conditions of constant gas pressure, the intens ity of coal will increase as confining pressure increases, the permeability of coal samples will decrease as confining pressure increases. Permeability curves from two conditions, basically rendering of "U", namely coal permeability with the increased weight of the shaft decreases and then increases. Different gas pressure loading and unloading of coal sample experiment at a constant axial strain stage, volumetric strain, radial strain uniform increases permeability beginning continued to decline, and then begins to increase permeability, the rate of increase is very small in the decline stage, permeability increases rapidly, and the greater is the gas pressure, permeability will be a corresponding increase. Experiment with different loading and unloading confining pressure conditions, the start of unloading confining pressure, axial pressure is constant axial strain, radial strain, volume strain begins to increase. And the smaller is the confining pressure, the greater is the rate of growth of three kinds of deformation. The greater is the confining pressure, the smaller is the initial permeability. The confining pressure of gas permeation have binding effect and ultimately penetration will not exceed the initial value.Fluid software FLUENT U-ventilation, U type ventilation + high pumping gas migration law in Lane two kinds of ventilation systems under simulated, the author obtained a higher work surface corner gas content at U type ventilation conditions, more than safety code requirements. U type ventilation + High Suction Road conditions, work surface corner gas content is reduced to less than 1%, improving the working face security conditions.By Yu Wu S2107 Coal Face High Suction Tunnel Found, the author draws a conclusion that a large amount of gas drainage, drainage of high concentration, while the high pumping Lane drainage reduces the amount of gas and the return airway gas concentrations. The analys is and comparison of High Suction Tunnel Gas Drainage and the amount of the corner gas content, draws high initial mining roadway drainage pumping gas is smaller, while the top corner gas concentration is very high. As mining begins with the development of fractures, the amount of gas by high drainage roadway drainage gradually increases, the upper corner gas content decreases, so high pumping Lane solved Face and corner gas gauge problem and improved safety conditions of the working face.