Outburst Prevention Technique Of Hydraulic Flushing In PanSan Mine

Coal as a kind of basic energy sources is the basic guarantee of realizing economic sustainable development in our country. At present, with the increase of depth of coal mining in our country, a large number of coal mines will be faced with so many serious problems, such as low permeability, high ground stress, high gas content, complex geological conditions, which is seriously restricts the safe and efficient mining of coal. Hydraulic flushing has advantage of simple operation, high safety, which can widely used in the low gas permeability coal seams, and the multiply of mining in our country has obtained the good effect of elimination processes.By analyzing the existing hydraulic flushing technology through access to information, understanding the structure characteristics of the water jet hydraulic flushhing, several kinds of common water jet coal hypothesis, water jet breaking coal process and influence factors, the hydraulic flushing antireflection mechanism. At the same time, simulating the process of the water jet breaking coal, the stress and strain of the coal body around the flushing hole before and after hydraulic punching through the ANSYS/LS-DYNA finite element software. The simulation shows that when the water jet pressure is10Mpa, coal eventually formed funnel-shaped crushing pit, coal is given priority to with crushing destruction, tensile fracture is complementary; After hydraulic flushing, under the action of stress around the borehole in the large areas of stress and strain concentration, coal move to the drilling direction, in the process of the movement of the coal, the coal body internal tensile stress and shear stress, Eventually led to the coal body broken and produce crack around the drilling, coal seam permeability is increased.Finally, through experimentation of hydraulic flushing in PanSan coal mine, single-hole landings at3t, the coal quantity and water pressure on the punching process, the relationship is not simple as a positive correlation,13-1the optimal coal flushing pressure is10to15Mpa; The coal amount increased with the increase of punch time, to a certain degree stabilized gradually; attenuation coefficient of gas flow rate was only about1/3before punching. Through continuous37days of the gas extraction, punch radius of influence is8.5m. Within the punch radius of influence, through the analysis of investigation of coal seam gas pressure and gas content dropped significantly, the gas extraction rate is high, obtains a good effect on elimination outburst. Therefore, the hydraulic flushing technology is worth popularizing application in low permeability and high gas-outburst coal seam.