System and method for automatically measuring and recording gas pressure during coal seam hole sealing

Abstract

The invention discloses a system and a method for automatically measuring and recording gas pressure during coal seam hole sealing. The system comprises a gas extraction hole sealing device comprising a gas extraction pipeline; a rubber baffle group is respectively sleeved at two ends of the gas extraction pipeline; a curing material conveying pipeline and a sealing fluid conveying pipeline whichare parallel to the gas extraction pipeline are respectively arranged outside the gas extraction pipeline; a port of the gas extraction pipeline is connected with a pressure recorder; an inlet end ofthe curing material conveying pipeline is connected with a curing material driving device through a curing material high-pressure pipeline; a curing material outlet is positioned in at least one rubber baffle group; an inlet end of the sealing fluid conveying pipeline is connected with a sealing fluid driving device through a sealing fluid high-pressure pipeline; and a sealing fluid outlet is positioned between two rubber baffle groups. The invention can seal the peripheral cracks of the gas extraction hole, prevent leakage of the measured gas and comprehensively record the gas pressure; and the pressure-measuring time is short, and the working efficiency is high.

Description

Technical field [0001] The invention relates to a system and method for automatically measuring and recording gas pressure in coal seam sealing holes, which is suitable for measuring the gas pressure of coal seams in various coal seams. Background technique [0002] Gas drainage is currently one of the most effective measures to reduce gas concentration in coal mining working faces and implement regional outburst prevention. The effect of gas drainage depends to a large extent on the hole sealing method and sealing quality. [0003] The gas sealing and pressure measurement systems commonly used in coal mines mainly include cement mortar sealing and pressure measurement systems, polyurethane hole sealing and pressure measurement systems, and apron pressure and mucus sealing pressure measurement systems. [0004] When using cement mortar to seal holes and measure pressure, cement mortar prepared from ordinary Portland cement is used. Due to the early chemical shrinkage and aut...

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Problems solved by technology

[0004] The cement mortar is used to seal the hole and measure the pressure. The cement mortar prepared by ordinary Portland cement is used. Due to the early chemical shrinkage and self-shrinkage of the cement and the later volume shrinkage caused by temperature changes and dry environments, etc., it will be to a certain extent. Increase the risk of cement shrinkage and cracking, resulting in plugging failure

[0005] Polyurethane sealing is used for pressure measurement. Due to the low compressive capacity of polyurethane material (uniaxial compressive capacity is 0.9-1.2Mpa), it is gradually compressed as time goes by, and its mechanical properties cannot prevent the creep of the drilled hole and the leakage of the air leakage channel. Formed, the seal is not firm, resulting in a sharp decrease in the gas drainage concentration in the later stage, and the sealing failure; moreover, because the polyurethane reacts too quickly and contains toxic substances, considering the rough manual sealing process and intense work, it may not all enter the drilled hole. The reaction is complete, causing the blocked drilling to be scrapped, and at the same time affecting the health of workers

[0006] Apron pressure mucus seals holes. Although the pressure mucus can seal the cracks around the drill hole in time, the mucus pressure is slightly higher than the gas pressure, but as time goes by, the mucus pressure releases and cannot achieve the effect of real-time monitoring and replenishment of mucus pressure; another On the one hand, the measured pressure data is single and irrelevant, and cannot reflect the change of gas pressure in the process of pressure measurement in real time; the national industry standard AQ / T 1047-2007 "Direct Measurement Method of Gas Pressure in Underground Coal Seams in Coal Mine" stipulates that the pressure change is less than 0.015 within 3 days Mpa is the real gas pressure of the coal seam, and the general pressure measurement pressure gauge has low accuracy and does not meet the pressure measurement requirements, which increases the uncertainty of the later mining work

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