Study On The Water Infusion Of The Borehole Along The Seam In Coal Mining Face

In this thesis, the wetting radius of coal seam water injection.was studied by thecombined method of theoretical analysis and laboratory experimental study andnumerical simulation and field test.Fractal model of radial flow in horizontal plane of thick coal seam injection andthe wetting radius calculation formula is established：Fractal model of horizontal plane parallel flow in thin coal layer injection and thewetting radius calculation formula is established：Use FLUENT numerical simulation software to study the rule of the wettingradius under different water injection pressure, different water injection time anddifferent permeability. Results show that:(1)under the conditions of the same waterinjection pressure and the same coal seam permeability, with the prolongation ofinjection time, the wetting radius became bigger. When the water injection timeincrese to8h, the radial wetting radius of the borehole has already exceeded5m.(2)under the conditions of the same injection time and the same coal seam permeability,with the increase of the injection pressure, the wetting radius was increase in a certainrange.(3)under the conditions of the same water injection pressure and the samewater injection time, the wetting radius increases with the increase of permeability,The effect of permeability on water injection was obvious.Conduct the coal seam water injection experiments in Baiping coal mine. Theexperimental results show that the distance range of the wetting radius was5-6m, theincrement of coal moisture was generally greater than1%, which has a certainregularity basically. Thus, the wetting radius can be determined about5-6m,which isclose to the theoretical calculation, and also close to the numerical simulation results,that proved the feasibility of the theoretical calculation formula.