In-situ gasification mining method of extremely thin coal seam group based on microwave radiation

Abstract

The invention discloses an in-situ gasification mining method for ultra-thin coal seam groups based on microwave radiation. The air intake shaft and the gas outlet shaft are constructed from the ground through the rock stratum to the ultra-thin coal seam, and water is constructed in the ultra-thin coal seam by the air intake shaft. Flat wells, horizontal wells run through the inlet well and the gas outlet well, and a microwave radiation well is constructed between the inlet well and the gas outlet well. The three wells are all connected to the horizontal wells in the coal seam group, and the O 2 and H 2 O, and use microwaves to radiate the water in the coal body. Because water is a strong microwave absorber, microwaves can heat water rapidly, and the high-temperature and high-pressure water vapor generated is conducive to the development of coal cracks and heat transfer. Vaporizes rapidly after full contact with reactive gas. The method fully utilizes the heat effect of microwave radiation to improve the in-situ gasification efficiency of coal body, has simple process and convenient operation, and has wide practicability in the technical field.

Description

technical field [0001] The invention relates to an in-situ gasification mining method, in particular to an in-situ gasification mining method for extremely thin coal seam groups based on microwave radiation, and belongs to the technical field of underground coal gasification. Background technique [0002] In the field of coal mining, with the continuous improvement of mining intensity, the reserves of thick and medium-thick coal seams in some mines are decreasing day by day, and extremely thin coal seams have gradually become the main coal mining seams. Coal seams with a thickness below 0.8m are called ultra-thin coal seams. The geological structure of ultra-thin coal seams is complex and distributed in groups; the mining height is low, which is not conducive to the use of large-scale mining equipment; The economic benefits are extremely low. Therefore, the mining of extremely thin coal seams is extremely difficult. Underground coal gasification is the controlled combustio...

AI Technical Summary

Problems solved by technology

However, the traditional ignition method is complicated in process and high in energy consumption. Due to the extremely poor thermal conductivity of coal, the temperature rise rate of coal body is slow. In addition, the injected H 2 O It is difficult to maintain the gasification state. Due to the extremely low permeability of the coal body, it is difficult for the reaction gas to fully contact the coal body, resulting in difficulty in coal gasification

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