CN-121994930-A - Top coal structure dynamic identification device and method based on sound-radon monitoring

CN121994930ACN 121994930 ACN121994930 ACN 121994930ACN-121994930-A

Abstract

The invention discloses a device and a method for dynamically identifying a top coal structure based on acoustic-radon monitoring, and relates to the technical field of underground mining of coal mines. The device comprises a probe rod main body, a radon measuring device and an acoustic wave detection device, wherein the probe rod main body comprises a head section rod body, a tail section rod body and a plurality of sections of middle rod bodies, the adjacent rod bodies are detachably and fixedly connected, the radon measuring device comprises a miniature electromagnetic valve and a radon measuring instrument, and the acoustic wave detection device comprises an acoustic wave transmitting probe, an acoustic wave receiving probe and an acoustic wave controller. Meanwhile, the radon concentration and the sound wave signals of each section are synchronously collected and fused and analyzed by controlling the miniature electromagnetic valve in a sectional way, so that the dynamic detection of the top coal structure is effectively realized, and the key technical support is provided for the fully mechanized caving face.

Inventors

ZHANG WEI
TANG JIEBING
FAN WEITAO
GAO SHANFENG
ZHANG DONGSHENG
YANG FEILI
WANG JINGCHENG
MA LIQIANG
MAO JINFENG
ZHAO LEILEI

Assignees

中国矿业大学
新疆工程学院

Dates

Publication Date: 20260508
Application Date: 20260228

Claims (10)

1. The device is characterized by comprising a probe rod main body, a radon measuring device and an acoustic wave detecting device; The probe rod main body comprises a head rod body (1), a tail rod body and a plurality of intermediate rod bodies (2), wherein adjacent rod bodies are detachably and fixedly connected, each rod body is of a double-pipe structure and comprises a pressure-bearing outer pipe (21) and a ventilation inner pipe (22), the pressure-bearing outer pipe (21) and the ventilation inner pipe (22) are hollow pipe bodies, the ventilation inner pipe (22) and the pressure-bearing outer pipe (21) are coaxially arranged and detachably and fixedly installed in the pressure-bearing outer pipe (21), and the top end of the head rod body (1) is closed; the radon measuring device comprises miniature electromagnetic valves (4) and radon measuring instruments (9), wherein a first through hole (212) is formed in a pressure-bearing outer pipe (21) of each rod body, a second through hole (221) is correspondingly formed in an inner ventilation pipe (22), the miniature electromagnetic valves (4) are arranged on connecting pipelines of the first through hole (212) and the second through hole (221), a plurality of miniature electromagnetic valves (4) are correspondingly arranged on the rod bodies, and are connected with an electromagnetic valve controller (42) together and are opened and closed under the control of the electromagnetic valve controller (42), and the radon measuring instruments (9) are communicated with the inner ventilation pipe (22); The sound wave detection device comprises sound wave probes and sound wave controllers (51), wherein the bottom end of a pressure-bearing outer tube (21) of each rod body is sleeved with an expansion rubber ring (7), a wire passing hole (213) and an air injection opening (214) are formed in the tube wall of the pressure-bearing outer tube (21) corresponding to the expansion rubber ring (7), the air injection opening (214) is communicated with an air injection opening of the expansion rubber ring (7), the sound wave probes are arranged on the periphery of the expansion rubber ring (7) and are a plurality of groups uniformly distributed along the circumferential direction of the expansion rubber ring (7), each group of sound wave probes comprises a sound wave transmitting probe and a plurality of sound wave receiving probes (5), one sound wave transmitting probe is arranged on the periphery of the expansion rubber ring (7) on the tail rod body, the plurality of sound wave receiving probes (5) are correspondingly arranged on the peripheries of the expansion rubber ring (7) on the first rod body (1) and the middle rod body (2), and wires of the sound wave transmitting probes (5) are led out through the wire passing holes (213) to be connected with the sound wave controllers (51).
2. The device for dynamically identifying the top coal structure based on the sound-radon monitoring is characterized in that a positioning bracket (23) is arranged between a pressure-bearing outer pipe (21) and an air ventilation inner pipe (22) in each section of rod body, the pressure-bearing outer pipe (21) and the air ventilation inner pipe (22) are detachably and fixedly connected through the positioning bracket (23), the positioning bracket (23) comprises a C-shaped clamp (232), a wing bracket (231) and a limiting boss (234), the C-shaped clamp (232) is clamped on the air ventilation inner pipe (22), the wing bracket (231) is in a sector shape, three wing brackets (232) are uniformly distributed along the circumferential direction of the C-shaped clamp (232), the limiting boss (234) is fixedly arranged on a sector-shaped surface of the wing bracket (231), a clamping groove (211) which is matched with the limiting boss (234) to limit is formed in the circumferential direction of the inner wall of the pressure-bearing outer pipe (21), and the limiting boss (234) is embedded in the clamping groove (211).
3. The device for dynamically identifying the roof coal structure based on the sound-radon monitoring according to claim 2 is characterized in that two groups of locating brackets (23) in each section of rod body are vertically and symmetrically arranged, two groups of clamping grooves (211) are axially arranged along the pressure-bearing outer tube (21), a wire buncher (233) is further arranged on each locating bracket (23), and the wire buncher (233) is arranged between the two wing brackets (231).
4. The device for dynamically identifying the top coal structure based on the sound-radon monitoring according to claim 1 is characterized by further comprising a filtering device (3), wherein the filtering device (3) is cylindrical, the filtering device is in threaded connection with the pressure-bearing outer tube (21) and is arranged in the first through hole (212), the filtering device (3) comprises a metal filter screen (31), a filter element (32) and a waterproof breathable membrane (33) which are sequentially arranged, the end of the waterproof breathable membrane (33) is close to the ventilation inner tube (22), and an electromagnetic valve interface (34) is further arranged on the filtering device (3).
5. The device for dynamically identifying the top coal structure based on the sound-radon monitoring is characterized in that an expansion rubber ring (7) is sleeved on the top end of the head section rod body (1), and a hydraulic expansion rigid ring is sleeved below the expansion rubber ring (7) on the tail section rod body.
6. The device for dynamically identifying the top coal structure based on the sound-radon monitoring, which is disclosed in claim 5, is characterized in that a mounting seat (74) is further sleeved at the position, sleeved with an expansion rubber ring (7), of each section of rod body, the mounting seat (74) is of an annular hollow structure, the expansion rubber ring (7) is arranged on the periphery of the mounting seat (74), the inner side surface of the expansion rubber ring is fixedly connected with the mounting seat (74), and the outer side surface of the expansion rubber ring is in contact with the wall of a drilling hole.
7. The dynamic recognition device for the top coal structure based on the sound-radon monitoring is characterized in that the sound wave probes are three groups uniformly distributed along the circumference of the expansion rubber ring (7), three sliding connecting rods (72) are arranged in each expansion rubber ring (7) corresponding to the sound wave transmitting probes or the sound wave receiving probes (5), one end of each sliding connecting rod (72) is connected with the mounting seat (74), the other end of each sliding connecting rod is connected with the expansion rubber ring (7) and moves outwards radially along with expansion of the expansion rubber ring (7), annular powerful magnet buckles (73) are adsorbed on one end of each sliding connecting rod (72) away from the corresponding mounting seat (74), and the sound wave transmitting probes or the sound wave receiving probes (5) are fixedly connected with the corresponding sliding connecting rods (72) through the powerful magnet buckles (73).
8. A method for roof coal structure identification using the acoustic-radon monitoring-based roof coal structure dynamic identification device as claimed in any one of claims 1 to 7, comprising the steps of: S1, modularly preassembling a segmented rod body on the ground, and installing a radon measuring device and an acoustic wave detecting device on the rod body; S2, constructing a drill hole according to the thickness of the top coal, selecting a corresponding number of standard length preassembled segmented rod bodies to install, arranging a first segment of rod body (1) at the topmost end and arranging a tail segment of rod body at the bottommost end, connecting each segment of miniature electromagnetic valve quick connection wire (41) with a main circuit of an electromagnetic valve controller (42), connecting each segment of sound wave probe quick connection wire (52) with a main circuit of an acoustic wave controller (51), connecting each segment of expansion rubber ring quick connection gas injection pipe (71) with a main circuit of an air pump (8), and orderly fixing all connecting cables along a wire binding device (233) on a positioning bracket (23) in the process; S3, slowly placing the assembled probe rod to the designed depth in a drill hole, injecting hydraulic oil into the hydraulic expansion steel ring (6) by utilizing a portable hydraulic pump until the hydraulic expansion steel ring is in stable contact with the wall of the drill hole, starting the air pump (8), injecting air into the expansion rubber ring (7) through the air injection opening (214) to expand the air and drive the sliding connecting rod (72) to move radially outwards until the outer side surface of the expansion rubber ring (7) is tightly attached to the wall of the drill hole, and at the moment, adsorbing and fixing the sound wave transmitting probe and the sound wave receiving probe (5) at the end part of the corresponding sliding connecting rod (72) through the strong magnet buckle (73) to realize good acoustic coupling with coal and rock mass; s4, setting corresponding measurement segment numbers for each connected segment rod body in an electromagnetic valve controller (42) and an acoustic wave controller (51), configuring the starting sequence, single opening duration and data acquisition sampling frequency of each miniature electromagnetic valve (4), and configuring acoustic wave signal characteristic parameters and the starting sequence of three groups of probes uniformly distributed along the circumferential direction of a probe rod main body; S5, according to the set sectional numbers, the corresponding miniature electromagnetic valve (4) is automatically controlled to be opened, under the action of negative pressure, radon gas in the coal rock mass cracks and pores enters the ventilation inner pipe (22) through the miniature electromagnetic valve (4) after being purified by the metal filter screen (31), the filter element (32) and the waterproof breathable film (33) and is then conveyed to the radon measuring instrument (9) at the orifice to measure the radioactivity specific activity and calculate the concentration; S6, constructing a curve of 'sound wave speed and top coal thickness' and a curve of 'radon gas concentration and top coal thickness' according to the data of the sound wave speed and radon gas concentration of each section acquired by the sound wave controller (51) and the radon detector (9), carrying out superposition analysis on the two curves, observing the corresponding relation of the change trend of the two curves, dynamically identifying and dividing the top coal structure types according to the radon gas concentration and sound wave propagation speed characteristics of the coal rock mass under different fracture conditions, and determining a coal rock boundary.
9. The method of claim 8, wherein in S5, the sound wave velocity calculation formula is: Wherein: v' k,i -k th group of one-emitting-multiple-receiving acoustic probes, wherein the wave speed of the i section is m/s; DeltaS i -the distance between the sound wave probes of each section of the probe rod, namely the length of each section of the probe rod, m; The time difference s between the i-th and i-1 sound wave receiving probes (5) in the DeltaT k,i -kth group of one-emitting and multiple-receiving sound wave probes; S i -the distance from the ith sound wave receiving probe (5) to the transmitting probe, m; S i-1 -ith 1 Distance from the sound wave receiving probe (5) to the transmitting probe, m; The time s when the ith sound wave receiving probe (5) in the T k,i -kth group of one-emitting and multi-receiving sound wave probes receives the sound wave signal; ith sound wave probe of T k,i-1 -kth group The time s when 1 sound wave receiving probe (5) receives the sound wave signal; V i -the average wave velocity of the i sections in the three groups of one-emitting and multi-receiving acoustic wave probes, m/s.
10. The method of claim 8, wherein in S6, the coal rock boundary is located at a position where the sonic velocity is sharply increased from a minimum value to a maximum value, and the radon concentration remains relatively high.

Description

Top coal structure dynamic identification device and method based on sound-radon monitoring Technical Field The invention relates to the technical field of top coal structure identification, in particular to a device and a method for dynamically identifying a top coal structure based on sound-radon monitoring. Background Fully-mechanized mining is one of important methods for mining thick coal seam, and the principle is that the upper top coal is crushed and discharged from a coal discharge port by utilizing the action of mine pressure while mining the lower part of the thick coal seam. The identification of the top coal structural state, particularly the identification of the coal-rock transition zone and the positioning of the crack development zone directly affect the coal discharging efficiency, the coal quality and the resource recovery rate, so that the accurate mastering of the top coal structural state has important significance for optimizing the coal discharging parameters, improving the resource recovery rate and reducing the gangue mixing. Traditional coal propping structure judgment mainly depends on experience of workers or single detection equipment. However, workers usually judge by observing the characteristics of coal and rock flow of a coal discharging port, listen to sound and the like, and the method has strong subjectivity, low reliability and high labor intensity and is seriously influenced by underground coal dust, illumination, noise and other environmental factors. The single physical quantity monitoring method such as vibration and acoustic emission method has large interference caused by vibration of mechanical equipment on working surface, low signal to noise ratio, the image and visual method has bad underground environment, large dust, low visibility and poor real-time performance, and the radar and gamma ray method has expensive equipment, high radiation safety risk and large popularization difficulty. Therefore, the invention is needed to provide a device capable of identifying the top coal structure in real time and accurately in an anti-interference way, and provides technical support for safe and efficient stoping of the fully mechanized caving face of the coal mine. Disclosure of Invention Aiming at the problems, the invention discloses a device and a method for dynamically identifying a top coal structure based on acoustic-radon monitoring, which are used for grasping the state of the top coal structure and judging the coal-rock interface by measuring the radon concentration and the acoustic propagation speed of a coal stratum, so that the accuracy and the reliability of the identification of the top coal structure and the coal-rock interface are remarkably improved. According to the invention, the device for dynamically identifying the top coal structure based on acoustic-radon monitoring comprises a probe rod main body, a radon measuring device and an acoustic wave detecting device; the probe rod main body comprises a head rod body, a tail rod body and a plurality of intermediate rod bodies, wherein adjacent rod bodies are detachably and fixedly connected, each rod body is of a double-pipe structure and comprises a pressure-bearing outer pipe and a ventilation inner pipe, the pressure-bearing outer pipe and the ventilation inner pipe are hollow pipe bodies, and the ventilation inner pipe and the pressure-bearing outer pipe are coaxially arranged and detachably and fixedly installed in the pressure-bearing outer pipe; The radon measuring device comprises miniature electromagnetic valves and radon measuring instruments, wherein a first through hole is formed in a pressure-bearing outer pipe of each rod body, a second through hole is correspondingly formed in an air ventilation inner pipe, the miniature electromagnetic valves are arranged on connecting pipes of the first through hole and the second through hole, a plurality of corresponding sections of rod bodies are arranged, and the miniature electromagnetic valves are jointly connected with an electromagnetic valve controller and are opened and closed under the control of the electromagnetic valve controller; The sound wave detection device comprises sound wave probes and a sound wave controller, wherein the bottom end of a pressure-bearing outer pipe of each rod body is sleeved with an expansion rubber ring, a wire passing hole and an air injecting hole are formed in the pipe wall of the pressure-bearing outer pipe corresponding to the expansion rubber ring, the air injecting hole is communicated with an air injecting hole of the expansion rubber ring, the sound wave probes are arranged on the periphery of the expansion rubber ring and are a plurality of groups uniformly distributed along the circumferential direction of the expansion rubber ring, each group of sound wave probes comprises a sound wave transmitting probe and a plurality of sound wave receiving probes, one sound wave transmitting probe is arranged on t