Gas extraction promoting method based on electrothermal effect

Abstract

The invention discloses a gas extraction promoting method based on electrothermal effect. The method includes that a gas extraction hole with a diameter ranging from 120 mm to 130 mm and a coal seam preheating hole with a diameter ranging from 30 mm to 50 mm are constructed in a coal seam; a thermal resistor is fed into the coal seam preheating hole and is connected with a power source through a wire, a sliding resistor is used for controlling circuit current change, and the thermal resistor is heated by current; the gas extraction hole is sealed by a conventional drill hole sealing method to guarantee that a gas extraction pipe exposes out of a seal material by 3-5 m, the gas extraction pipe is connected with an underground gas pipeline through a valve for gas extraction, the coal seam receives heat, the temperature of the coal seam rises, and gas adsorbed in the coal seam is desorbed as free gas, so that gas extraction is promoted. The gas extraction promoting method based on electrothermal effect has the advantages of larger gas desorption affecting area, higher extracted gas concentration, remarkable effect and capability of meeting the needs of gas control of coal mine field areas and the like.

Description

technical field [0001] The invention relates to a method for promoting gas drainage based on an electrothermal effect, which belongs to the technical field of regional gas control in underground coal mines, and is especially suitable for the gas drainage operation of regional gas control in high-adsorption gas and low-permeability coal seams. Background technique [0002] The geological conditions of my country's coal mines are complex, high-gas coal seams account for 50%-70%, and high-gas low-permeability coal seams account for about 70% of them. With the efficient intensification of coal production and the increase of mining depth, the amount of gas gushing out is increasing, and the threat of gas explosion and gas outburst is becoming more and more serious. At present, the fundamental method to prevent and control coal mine gas disasters is to carry out gas drainage. The coal mine gas management policy of "draining first, then mining, monitoring and monitoring, and wind ...

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Problems solved by technology

[0003] However, the above methods are likely to cause local stress concentration, inhibit gas desorption, coal and rock movement, and even induce coal and gas outburst and other negative effects

The main reason is that after the implementation of traditional hydraulic technology, the existence of water blocks the gas flow channel, which inhibits gas desorption, diffusion and infiltration, resulting in unsatisfactory gas drainage effects and effective suppression of gas disaster coal samples; loose blasting is easy Induce the sudden release of gas, causing secondary gas disasters

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