Numerical simulation study on gas drainage by interval hydraulic flushing in coal seam working face

In order to solve the problem of difficult gas extraction in coal mine, a method from seam by interval hydraulic flushing is put forward. Based on occurrence conditions 7609 working face Wuyang Coal Mine, numerical simulation research drainage ordinary drilling and was carried out using COMSOL software. The results show that with increase quantity, effective radius also increases. 0.5 m, 1.0 1.2 m 1.3 respectively when quantity 0.5t/m, 1.0t/m 1.5t/m. As multiple boreholes are drained at same time, will affect each other, which reduce pressure radius, spacing between can be greater than twice single borehole arranging boreholes. And smaller interval, more uniform reduction area. According results, test were field. Through observation analysis, concentration module increased 31.2% purity 5.77 times compared module. It shows effectively improve effect.