Study On The Technology Of Increasing Drainage In High Gas And Low Air Permeability Coal Seam

In view of the low permeability and high gas-outburst coal seam of the excavating working faces, this dissertation advances a new technology that uses long-hole pre-splitting controlling blast worked along with long borehole draining。 Based on the theory of seam gas occurrence and fluid and the mechanism of long-hole pre-splitting controlling blast, the computer simulation and analysis have been done with the aid of FLUENT and MATLAB。 Moreover, after combining the on-the-spot data of the PanSan Coal Mine, the optimum plan for the drill arrangement and the parameters of blast have been make out。The study shows that by taking the new technology it can not only make the breaks and the permeability coefficient much larger around the boreholes, raise the total gas-draining quantity greatly, and shorten the pre-drainage time greatly; but also extend the efficient draining radius largely after blast, improve the gas suction rate greatly, and reduce the menace of coal-and-gas outburst. Therefore, it provides a valuable reference to the combined management of coal gas, and makes the problem of disallowed gas concentration and gas outburst solved。...