CN-115822712-B - Accurate judging method for spontaneous combustion risk position of coal pillar coal

CN115822712BCN 115822712 BCN115822712 BCN 115822712BCN-115822712-B

Abstract

The invention discloses a precise judgment method for spontaneous combustion positions of coal pillars, and relates to the technical field of coal mine safety. The method comprises the steps of firstly monitoring deformation and crushing states of the surface of a coal pillar, determining possible risk sections with air leakage cracks or spontaneous combustion of coal, then judging whether the risk sections of the coal pillar have formed air leakage cracks or not by adopting a section air leakage detection mode, determining the positions and the air leakage speeds of the corresponding air leakage cracks, and finally measuring the positions of the coal spontaneous combustion high temperature risks and the migration trend of the coal spontaneous combustion high temperature risks along with tunneling or stoping of a roadway in the sections with the judged air leakage cracks by arranging temperature measuring points and temperature and gas concentration monitoring modes. The method is combined with a plurality of detection technologies to pre-judge and determine the positions of the air leakage cracks of the coal pillars and the coal spontaneous combustion high-temperature risks of the coal pillars in the tunneling period and the working face stoping period from a plurality of different dimensions, so that the tunneling and production safety of the coal pillars in the gob-side entry driving arrangement mode can be further improved, and the method has an important effect on mines adopting the coal pillar gob-side entry driving arrangement mode.

Inventors

QIN BOTAO
Luo zhongzheng
TIAN SIYU
MA DONG
GAO YUAN
SHENG PENG

Assignees

中国矿业大学

Dates

Publication Date: 20260508
Application Date: 20220902

Claims (6)

1. The accurate judging method for the spontaneous combustion risk position of the coal pillar coal is characterized by comprising the following steps of: S1, monitoring deformation of a coal pillar (7), periodically inspecting the broken state of the surface of the coal pillar (7), and determining potential air leakage cracks (4) and risk sections of spontaneous combustion of coal according to monitoring and inspection results, wherein the method comprises the following steps: s11, arranging a displacement sensor and a stress meter on the surface of the coal pillar (7), monitoring the displacement and the stress state of the surface of the coal pillar (7) in real time, and reflecting the compression condition of the surface of the coal pillar (7) and the coal body (1) of the coal pillar through the data change of the displacement sensor and the stress meter; S12, when the displacement sensor and stress meter data reach or exceed critical values epsilon t and sigma t , corresponding displacement and stress data are recorded, corresponding position data are recorded, and the corresponding position is a risk point; s13, recording the measured risk points, inspecting the sections with denser risk points, inspecting the surface crack development condition of the corresponding sections, and recording the sections with denser risk points and found that obvious surface cracks exist in inspection as potential air leakage cracks (4) and coal spontaneous combustion risk sections; s2, adopting a section air leakage detection mode for the potential air leakage cracks (4) and the coal spontaneous combustion risk section determined in the step one, and judging whether the air leakage cracks (4) exist in the coal pillar (7) or not and the positions and the air leakage speeds of the air leakage cracks (4) are located; S3, burying a temperature sensor in the section of the coal pillar (7) with the air leakage crack (4) determined in the step two, measuring the coal pillar coal spontaneous combustion high temperature risk position (5) and the migration trend of the coal pillar coal spontaneous combustion high temperature risk position (5) which are arranged in the coal pillar (7) in a measuring point arrangement and real-time monitoring mode, and determining the coal pillar coal spontaneous combustion high temperature risk position (5) which is arranged in the coal pillar (7).
2. The accurate judging method of the spontaneous combustion risk position of the coal pillar coal according to claim 1, wherein after the risk position is determined, gas concentration monitoring is carried out on a tunneling roadway of the coal pillar (7) every two to three days in each interval during tunneling or stoping of the coal pillar (7), a dangerous section is further determined based on the change of oxygen concentration and index gas concentration between two adjacent measuring points, and if the phenomenon of oxygen concentration reduction and index gas concentration increase exists between the two adjacent measuring points at the same time, the section corresponding to the two measuring points is indicated to be the dangerous section possibly having an air leakage crack (4) or a spontaneous combustion high-temperature risk position (5) of the coal pillar coal.
3. The method for accurately judging the spontaneous combustion risk position of the coal pillar coal according to claim 2, wherein the gas concentration monitoring is carried out in sections in a tunneling roadway, each section is 100-150 m, and the monitored gas is coal spontaneous combustion index gas containing oxygen, carbon monoxide and alkane gas.
4. The method for accurately judging the spontaneous combustion risk position of coal pillar coal according to claim 2, wherein a handheld gas concentration detector is combined with a ball bladder gas sample collection for gas concentration monitoring, the ball bladder collected gas sample is analyzed by a gas chromatography detector on the ground, and analysis results and data detected by the handheld gas concentration detector are recorded on a table at the same time so as to ensure the accuracy of detection results.
5. The method for accurately judging the spontaneous combustion risk position of coal pillar coal according to claim 1, wherein in the second step, the section air leakage detection is performed by adopting a trace gas concentration detection mode, the trace gas concentration detection is performed by adopting a handheld gas concentration detector to be combined with a ball bladder gas sample collection, the gas sample collected by the ball bladder is analyzed by a gas chromatography detector on the ground, and the analysis result and data detected by the handheld gas concentration detector are recorded on a table at the same time so as to ensure the accuracy of the detection result.
6. The accurate judging method of the spontaneous combustion risk positions of the coal pillars is characterized in that in the third step, the arrangement of the measuring points is based on the positions of the air leakage cracks (4) and the corresponding risk sections determined in the second step, one temperature measuring drill hole (2) is arranged in each risk section coal pillar (1) at 3-5 m intervals, the depth of each temperature measuring drill hole (2) is 1-2 m, a group of temperature sensors (3) are buried at the bottoms of the drill holes, after the arrangement of the measuring points is completed, the temperature data of each measuring point are detected and collected every day or every two days, the temperature data of each measuring point are uniformly arranged and summarized to prepare a temperature data statistical table, a position temperature trend image and a temperature change trend chart taking time as an axis are drawn, the temperature change rule in the sections of the coal pillars (7) is summarized, and finally the spontaneous combustion high-temperature risk positions (5) of the coal pillars existing in the coal pillars (7) are determined.

Description

Accurate judging method for spontaneous combustion risk position of coal pillar coal Technical Field The invention relates to the technical field of coal mine safety, in particular to a method for accurately judging the spontaneous combustion risk position of coal pillars. Background The coal pillar gob-side entry driving has the advantages of high recovery rate, low supporting cost and the like, not only can increase the economic benefit of coal mines, but also can improve the stress environment of surrounding rocks of the tunnel and reduce the occurrence of mine pressure accidents. However, as the coal pillar is a porous medium coal rock body, cracks or shortages are extremely easy to generate under the disturbance of stress in the tunneling and stoping processes, not only is an air leakage channel easily formed to cause spontaneous combustion of the residual coal in the goaf, but also the coal pillar is easily influenced by air leakage to generate oxidation heating points or natural ignition under specific conditions, thereby bringing great threat to the underground production safety. The method is mainly used for qualitatively judging the air leakage state of the coal pillar, but cannot determine the specific positions of the air leakage channel and the oxidation heating dangerous area of the coal pillar which is already crisp or generates cracks. Disclosure of Invention Aiming at the defects of the prior art in aspects of coal pillar air leakage and dangerous area monitoring, the invention provides a method for combining coal pillar deformation monitoring, section air leakage detection and key area temperature monitoring, and the dangerous areas and the dangerous sections of the coal pillar during tunneling and working face extraction are pre-judged and determined from a plurality of different dimensions. The invention provides a precise judgment method for the spontaneous combustion risk position of coal pillar coal, which comprises the following steps: monitoring the deformation of the coal pillar, periodically inspecting the broken state of the surface of the coal pillar, and determining potential air leakage cracks and risk sections of spontaneous combustion of coal according to the monitoring and inspection results. And step two, adopting a section air leakage detection mode for the potential air leakage cracks and the risk sections of spontaneous combustion of the coal determined in the step one to judge whether the coal pillar has the air leakage cracks and the positions and the air leakage speeds of the air leakage cracks. Burying a temperature sensor in the coal pillar section with the air leakage crack determined in the step II, measuring the coal pillar coal spontaneous combustion high temperature risk position and the migration trend of the coal pillar coal spontaneous combustion high temperature risk position in the coal pillar in a measuring point arrangement and real-time monitoring mode, and determining the coal pillar coal spontaneous combustion high temperature risk position in the coal pillar. Preferably, after the risk position is determined, the coal pillar tunneling roadway is monitored for gas concentration once every two to three days in the coal pillar tunneling or stoping period, the dangerous section is further determined based on the change of the oxygen concentration and the index gas concentration between two adjacent measuring points, and if the phenomena of the reduction of the oxygen concentration and the increase of the index gas concentration exist at two adjacent measuring points at the same time, the section corresponding to the two measuring points is the dangerous section which possibly has the air leakage crack or the spontaneous combustion high-temperature risk position of the coal pillar coal. Preferably, the gas concentration monitoring is carried out in sections in the tunneling roadway, each section is 100-150 m, and the monitored gas is coal spontaneous combustion index gas containing oxygen, carbon monoxide and alkane gas. Preferably, the gas concentration monitoring adopts a handheld gas concentration detector to collect the gas sample of the ball, the gas sample collected by the ball is analyzed by a gas chromatograph detector on the ground, and the analysis result and the data detected by the handheld gas concentration detector are recorded on a table at the same time so as to ensure the accuracy of the detection result. Preferably, in the first step, the method for determining the potential air leakage crack and the risk section of spontaneous combustion of coal according to deformation monitoring and periodic inspection comprises the following steps: And S1, arranging a displacement sensor and a stress meter on the surface of the coal pillar, monitoring the displacement and stress state of the surface of the coal pillar in real time, and reflecting the compression condition of the surface of the coal pillar and the coal body of the coal pillar through