Abstract: A method for extracting gas by fracturing a coal seam through a combination of hydraulic slotting and multi-stage combustion impact wave comprises cutting slots in an impact borehole using a hydraulic slotting equipment to perform pressure relief and permeability enhancement on a coal seam and enlarge a N2 (nitrogen gas) or CO2 (carbon dioxide gas) storage space, injecting a large amount of N2 or CO2 into the borehole by means of a high pressure gas cylinder and a pressure reducing valve through a gas injection and extraction pipe, then injecting a certain amount of methane and dry air into a high-temperature and high-pressure combustion chamber by means of the high pressure gas cylinder and the pressure reducing valve, so that the gases are mixed and combusted to form high-temperature and high-pressure impact wave to push a piston to compress the N2 or CO2, thereby generating a large number of factures on the coal seam around the impact borehole under guiding action of the slots.

Abstract: The disclosure provides a method for extracting gas by fracturing a coal seam through a combination of hydraulic slotting and multi-stage combustion impact wave, comprising first cutting slots in an impact borehole using a hydraulic slotting equipment to perform pressure relief and permeability enhancement on a coal seam and enlarge a N2 or CO2 storage space, then injecting a large amount of N2 or CO2 into the borehole by means of a high pressure gas cylinder and a pressure reducing valve through a gas injection and extraction pipe, then injecting a certain amount of methane and dry air into a high-temperature and high-pressure combustion chamber by means of the high pressure gas cylinder and the pressure reducing valve, so that the gases are mixed and combusted to form high-temperature and high-pressure impact wave to push a piston to compress the N2 or CO2, thereby generating a large number of factures on the coal seam around the impact borehole under guiding action of the slots.

Abstract: Disclosed is a self-regenerative integrated device for the synergetic oxidation of low-concentration gas and ventilation gas in a coal mine. The integrated device comprises a metal shell (5). A honeycomb ceramic oxidation bed (13) is arranged within the metal shell (5) and divided into a regenerative section (40) and an oxidation section (41) by a heat exchange chamber (14). A first cavity between the regenerative section (40) and the inner wall of the metal shell (5) is divided into a first inlet chamber (6) and an exhaust chamber (8) by an inlet partition plate (7), a second cavity between the oxidation section (41) and the inner wall of the metal shell (5) is divided into a second inlet chamber (22) and a mixing chamber (20) by a partition plate (21) for averaging gas, and a plurality of gas nozzles (28) are provided on the partition plate (21) for averaging gas.

Abstract: A distributed combined cooling, heating and power energy system for gas extraction in a coal mining area, which belongs to an energy system for gas production.

Abstract: Disclosed is a self-regenerative integrated device for the synergetic oxidation of low-concentration gas and ventilation gas in a coal mine. The integrated device comprises a metal shell (5). A honeycomb ceramic oxidation bed (13) is arranged within the metal shell (5) and divided into a regenerative section (40) and an oxidation section (41) by a heat exchange chamber (14). A first cavity between the regenerative section (40) and the inner wall of the metal shell (5) is divided into a first inlet chamber (6) and an exhaust chamber (8) by an inlet partition plate (7), a second cavity between the oxidation section (41) and the inner wall of the metal shell (5) is divided into a second inlet chamber (22) and a mixing chamber (20) by a partition plate (21) for averaging gas, and a plurality of gas nozzles (28) are provided on the partition plate (21) for averaging gas.

Abstract: A distributed combined cooling, heating and power energy system for gas extraction in a coal mining area, which belongs to an energy system for gas production.