The Research On Seepage Characteristic Of Water Infusion For Coal Seam And Numerical Simulation Analysis

Water injection in coal seam as main technical measure for preventing coal dust, have a widely use over the world. Characteristic of water seepage in coal bed during water injection are studied by theory analyze, experimental study, numerical simulation and spot testing. firstly, develop permeability testing device of coal sample, and have an experimental study on mechanism of injection water flow in coal bed, including the influence of factors such as confining and entrance water pressure (simulate injection water pressure)on permeability; later, give an numerical simulation analysis to water pressure and seepage speed distribution under different water injection pressure by comsol simulation software; at last, give a analysis on relationship of infusion pressure and such as injection mounts,and investigate the wetness radius of 12128 coal face under different injection pressure.The experimental research shows that, the relationship of coal permeability and confining pressure is mathematic quadratic polynomial; permeability is sensitive to stress, different coal sample have same sensitiveness to stress; the permeability of coal sample have an up trend accompany the rise of holder entrance water pressure, it is approximate cubic polynomial between coal permeability and entrance water pressure, entrance pressure have less influence to coal permeability when surpass the constant value; from the result of simulation,water pressure of pore decrease gradually along the center of drill hole, the water pressure distribution near the drill hole approximate as oval and extend to the surrounding, the wetness zone extending continuously when the injection water pressure increase, the speed of water flow near the drilling hole is higher, water flow extend to surroundings along the drilling hole, and later, the speed of water flow changing lower; it is linear relationship that injection water amounts of 12128 coal face single hole and injection water pressure, the relationship of injection parameters in spot are coincide with result of experimental study, when injection pressure increase,wetness radius have a greater scope,the result of investigating in spot nearly have same regular pattern with the result of simulation.