A method for gas drainage by pre-cracking high-stress and low-porosity coal seams

Abstract

The invention discloses a system and method for pre-splitting, anti-reflection, and gas drainage of high-stress and low-porosity coal seams, which includes a pre-splitting device, and the pre-splitting device includes an exhaust casing, and multiple gas outlets are evenly arranged on the exhaust casing. A vent hole, the rear part of the exhaust shell is provided with a blasting tube, the blasting tube is provided with a liquid carbon dioxide storage pipe, and the front end of the liquid carbon dioxide storage pipe entering the exhaust area is blocked with everything A variable disc, the liquid carbon dioxide storage pipeline is provided with a heating element; the rear end of the liquid carbon dioxide storage pipeline is provided with a liquid injection terminal, and the liquid injection terminal is provided with a liquid injection port, and the liquid injection port It communicates with the liquid carbon dioxide storage pipeline, and the liquid injection end is provided with an electrode for leading to the outside, and the electrode is connected with the heating element circuit. It can effectively increase the density and range of coal fractures, change the state of coal primary fractures, and improve the efficiency and safety of gas drainage.

Description

technical field [0001] The invention relates to the field of disaster prevention and control in coal mining working faces, in particular to a system and method for pre-splitting high-stress and low-porosity coal seam pre-splitting, improving permeability, and draining gas. Background technique [0002] In the process of coal mining, gas is one of the biggest threats. Gas explosion, coal and gas outburst disasters restrict the safe production of coal mine industry in my country. Gas drainage is the most effective measure to solve this threat. The most important method of gas management and utilization can fundamentally eliminate or reduce the source of gas in the working face, and the extracted gas can be used intensively. The geological mining conditions of coal seams in my country are complex. Compared with foreign coal seams, it has the characteristics of low strength and poor permeability. With the continuous increase of coal mining intensity and depth, under the conditio...

AI Technical Summary

Problems solved by technology

[0003] There are many shortcomings in the traditional anti-reflection technology. For example, although the hydraulic anti-reflection technology uses high-pressure water pump to inject water, although the scope of application is broadened, the pressure provided by the water pump is limited, and the micro-cracks generated are few, so it is difficult to achieve the desired effect; In addition, the pressure of the water injection pump The higher the value, the higher the operation, maintenance and management costs of the equipment

Explosive blasting anti-reflection technology has limited adaptability, complex operation process, and low safety factor. The possibility of dumb guns cannot be ruled out. The heat generated by blasting can easily ignite and detonate the gas stored in the coal body. In high gas mines and coal and gas outbursts Disabled in mines

The intensive cross-drilling method requires a large amount of engineering, has little effect on the development of secondary fractures in the coal body, and has poor permeability enhancement effect

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