A high-efficiency coal underground gasifier and its construction method

Abstract

The invention discloses an efficient coal underground gasifier and a construction method thereof. The efficient coal underground gasifier includes an igniting channel, a gas collection channel, gas inlet channels, and a gas outlet channel that are arranged at a quadrilateral coal layer block, the horizontal distance of the gas outlet channel at the edge of the quadrilateral coal layer block from the gas collection channel is more than 10m, a backward combustion method is adopted to expand the cross section of the gas collection channel to be more than 2*2m<2>, and the plurality of gas inlet channels spacing at a certain distance are communicated with the expanded gas collection channel at the lower side to realize gas collection; and when the fire zone working face in the gas collection channel retreats to the vicinity of an outlet hole, the fracturing and reverse fire penetration combustion are carried out at the hole to communicate the gas outlet channel and the gas collection channel. The efficient coal underground gasifier can realize the parallel gasification of the plurality of gas inlet channels, so that the productivity of the gasifier is improved. By means of the methods of backward combustion and reverse penetration, the construction period of the gasifier is shortened. A gas outlet system consisting of vertical boreholes is arranged outside the stress concentration zone to improve the stability of the gas outlet system.

Description

technical field [0001] The invention relates to an underground coal gasification mining technology, in particular to a high-efficiency underground coal gasification furnace and a construction method thereof, which are suitable for high-efficiency underground gasification mining of coal seams of different occurrence states. Background technique [0002] Wellless underground coal gasification is the process of gasification by constructing geological drilling holes in the original underground coal seam. The original coal seams in different regions have different occurrence states, and the existing single-form underground gasifier cannot achieve effective coverage of coal resources from an economical and reasonable perspective; at the same time, the gas directly gasified in the gasification channel contains ash and high temperature. , high pressure, which will cause the gas outlet hole to block and deform; in addition, conventional underground gasifiers will form a large fuel-ai...

AI Technical Summary

Problems solved by technology

The original coal seams in different regions have different occurrence states, and the existing single-form underground gasifier cannot effectively cover coal resources from an economical and reasonable point of view; at the same time, the coal gas directly gasified in the gasification channel contains ash and high temperature , high pressure, which will cause blockage and deformation of the gas outlet borehole; in addition, conventional underground gasifiers will form a large burnout area at the bottom of the vertical gas outlet borehole, resulting in stress concentration at the bottom of the borehole and affecting the stable gas outlet of the borehole

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