阅读说明：本技术 一种矿用监测设备及采空区气体监测方法 (Mining monitoring equipment and goaf gas monitoring method ) 是由 侯树宏 胡文博 田文华 秦汝祥 景巨栋 何维胜 康新荣 冯涛 李宁 杨志华 田文 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种矿用监测设备及采空区气体监测方法,包括气相色谱仪、井下气体传输机构和气路切换机构。本发明公开的一种矿用监测设备及采空区气体监测方法,可以对采空区中的气体进行实地监测,通过气路切换机构可以实现自动切换气路,以供气相色谱仪对每个监测点中的气体进行分析,通过布置压差测量仪,可以对两个监测点的压差或能位进行监测,操作方便,可以为采空区漏风与遗煤自燃研究提供较为准确的监测结果。(The invention discloses a mining monitoring device and a goaf gas monitoring method. The mining monitoring equipment and the goaf gas monitoring method disclosed by the invention can be used for monitoring gas in the goaf on site, can realize automatic gas circuit switching through the gas circuit switching mechanism, can be used for analyzing the gas in each monitoring point by a gas chromatograph, can be used for monitoring the pressure difference or energy level of the two monitoring points by arranging the pressure difference measuring instrument, are convenient to operate, and can provide more accurate monitoring results for research on goaf air leakage and spontaneous combustion of residual coal.)

1. The mining monitoring equipment is characterized by comprising a gas chromatograph, an underground gas transmission mechanism and a gas path switching mechanism;

the underground gas transmission mechanism comprises a protection pipe, a plurality of gas inlet heads arranged on the protection pipe and a plurality of gas conveying pipes positioned in the protection pipe, wherein each gas inlet head is connected with one gas conveying pipe;

the gas circuit switching mechanism comprises a box body with an air outlet, a fixed disc arranged in the box body, a rotating disc arranged in the box body and a driving mechanism which is arranged in the box body and is used for driving the rotating disc to rotate;

the fixed disk is provided with a plurality of fixed disk vent holes, and each gas conveying pipe is connected with one fixed disk vent hole;

the rotating disc is provided with a rotating disc vent hole and a plurality of rotating disc exhaust holes;

when the rotating disc vent hole is in butt joint communication with one fixed disc vent hole, each rest fixed disc vent hole is in butt joint communication with one rotating disc exhaust hole respectively;

a rotating shaft air passage is arranged on a rotating disc rotating shaft of the rotating disc, and a rotating disc air passage communicated with the rotating shaft air passage and the rotating disc vent hole is arranged in the rotating disc;

the end part of the rotating disc rotating shaft is provided with a sealing end cover, the gas chromatograph is communicated with the rotating shaft air passage through a first vent pipeline, and a first valve is arranged on the first vent pipeline.

2. The mining monitoring device of claim 1, wherein the rotating disc air vents and each of the rotating disc air vents are provided with a telescopic docking arrangement capable of docking and undocking with the fixed disc air vents.

3. The mining monitoring device of claim 2, wherein the telescopic docking arrangement comprises a fixed sleeve fixedly mounted on the rotatable disc and a sliding sleeve slidably connected to the fixed sleeve;

and a piston used for driving the sliding sleeve to stretch is arranged between the fixed sleeve and the sliding sleeve.

4. The mining monitoring device of claim 1, wherein the drive mechanism includes a stepper motor and a drive gear;

a gear rotating shaft of the transmission gear is arranged in the box body through a bracket;

an output shaft of the stepping motor is connected with the gear rotating shaft;

and a rotating disc gear is arranged on the peripheral surface of the rotating disc and is meshed with the transmission gear.

5. The mining monitoring device of claim 1, wherein the protection pipe comprises a main pipe arranged in a roadway and a secondary pipe arranged in a goaf, and the secondary pipe is connected with the main pipe in an L shape;

the air inlet head is arranged on the auxiliary pipe.

6. The mining monitoring device of claim 5, wherein the air intake head includes an air intake end and a connection end connected to the air intake end;

the connecting end is positioned in the auxiliary pipe, and the gas conveying pipe is connected with the connecting end;

the air inlet end is located on the outer side of the auxiliary pipe, and a plurality of air inlets are formed in the air inlet end.

7. The mining monitoring device of claim 6, wherein the air inlet end is spherical.

8. The mining monitoring device of any of claims 1-7,

the mining monitoring equipment comprises two sets of underground gas transmission mechanisms, two sets of gas circuit switching mechanisms and a differential pressure measuring instrument;

each set of gas path switching mechanism is arranged between the gas chromatograph and one set of underground gas transmission mechanism;

the gas chromatograph is communicated with the rotating shaft air passages in the two sets of gas path switching mechanisms through the two first channel pipelines;

two gas input ends of the differential pressure measuring instrument are respectively communicated with the rotating shaft gas passages in the two sets of gas path switching mechanisms through a second vent pipeline, and a second valve is arranged on the second vent pipeline.

9. A goaf gas monitoring method, characterised in that a mine monitoring apparatus as claimed in any one of claims 1 to 8 is employed, comprising the steps of:

s01: a gas chromatograph, an underground gas transmission mechanism and a gas circuit switching mechanism are arranged in advance, so that an air inlet head is positioned in a goaf;

s02: gas transmitted from each air inlet head is monitored and analyzed by a gas chromatograph at regular time every day, and the rotating disc is driven to rotate by a driving mechanism so as to realize air path switching;

s03: and the gas chromatograph transmits the gas data to the control processing equipment, and the control processing equipment processes and stores the daily gas data of each gas inlet head.

10. A goaf gas monitoring method in accordance with claim 9 further comprising the steps of:

the pressure difference of the gas transmitted from the two air inlet heads in the two sets of air path switching mechanisms is monitored by a pressure difference measuring instrument every day at regular time, the pressure difference is transmitted to a control processing device, and the control processing device processes and stores the pressure difference of every two air inlet heads every day.

Technical Field

The invention relates to the field of mine ventilation safety, in particular to a mine monitoring device and a goaf gas monitoring method.

Background

In the working face mining process, a top plate behind the hydraulic support falls off to form a goaf of porous media. Because the air current makes a 90-degree right-angle turn at the lower corner of the working surface, part of the air current enters the goaf to form air leakage under the influence of inertia. Under the influence of the distribution of the energy level or the air pressure difference of the working surface, the air leakage of the goaf can enter the roadway space again from the upper corner of the working surface. At the moment, leaked air carries harmful gas in the goaf to enter the roadway space together, and the production safety of the working face is threatened. Meanwhile, the air flow of the goaf creates conditions for oxidizing residual coal in the goaf, and potential safety hazards of spontaneous combustion of the goaf are formed. The gas composition and concentration in the goaf and the energy contributing to air leakage are the main research contents for determining the goaf danger.

At present, theoretical analysis, numerical simulation, analog simulation and field actual measurement methods are mainly adopted for the research on air leakage of a goaf on a working face, wherein the field actual measurement is the most real and reliable method and is widely applied, and tracer gas is generally adopted for detection. However, the key of trace gas detection is detection timing, release point arrangement and gas sample collection point arrangement, and it is often difficult to obtain effective results.

In view of the above, it is necessary to provide a monitoring device and a goaf gas monitoring method capable of performing actual measurement on a goaf site.

Disclosure of Invention

The technical scheme of the invention provides a mining monitoring device, which comprises a gas chromatograph, an underground gas transmission mechanism and a gas path switching mechanism;

the underground gas transmission mechanism comprises a protection pipe, a plurality of gas inlet heads arranged on the protection pipe and a plurality of gas conveying pipes positioned in the protection pipe, wherein each gas inlet head is connected with one gas conveying pipe;

the gas circuit switching mechanism comprises a box body with an air outlet, a fixed disc arranged in the box body, a rotating disc arranged in the box body and a driving mechanism which is arranged in the box body and is used for driving the rotating disc to rotate;

the fixed disk is provided with a plurality of fixed disk vent holes, and each gas conveying pipe is connected with one fixed disk vent hole;

the rotating disc is provided with a rotating disc vent hole and a plurality of rotating disc exhaust holes;

when the rotating disc vent hole is in butt joint communication with one fixed disc vent hole, each rest fixed disc vent hole is in butt joint communication with one rotating disc exhaust hole respectively;

a rotating shaft air passage is arranged on a rotating disc rotating shaft of the rotating disc, and a rotating disc air passage communicated with the rotating shaft air passage and the rotating disc vent hole is arranged in the rotating disc;

the end part of the rotating disc rotating shaft is provided with a sealing end cover, the gas chromatograph is communicated with the rotating shaft air passage through a first vent pipeline, and a first valve is arranged on the first vent pipeline.

Furthermore, the rotary disc vent holes and each rotary disc exhaust hole are provided with telescopic butt joint devices capable of being in butt joint with and separated from the fixed disc vent holes.

Furthermore, the telescopic butt joint device comprises a fixed sleeve fixedly arranged on the rotating disc and a sliding sleeve in sliding connection with the fixed sleeve;

and a piston used for driving the sliding sleeve to stretch is arranged between the fixed sleeve and the sliding sleeve.

Further, the driving mechanism comprises a stepping motor and a transmission gear;

a gear rotating shaft of the transmission gear is arranged in the box body through a bracket;

an output shaft of the stepping motor is connected with the gear rotating shaft;

and a rotating disc gear is arranged on the peripheral surface of the rotating disc and is meshed with the transmission gear.

Further, the protection pipe comprises a main pipe arranged in a roadway and a secondary pipe placed in the goaf, and the secondary pipe is connected with the main pipe in an L shape;

the air inlet head is arranged on the auxiliary pipe.

Furthermore, the air inlet head comprises an air inlet end and a connecting end connected with the air inlet end;

the connecting end is positioned in the auxiliary pipe, and the gas conveying pipe is connected with the connecting end;

the air inlet end is located on the outer side of the auxiliary pipe, and a plurality of air inlets are formed in the air inlet end.

Further, the air inlet end is spherical.

Furthermore, the mining monitoring equipment comprises two sets of underground gas transmission mechanisms, two sets of gas path switching mechanisms and a differential pressure measuring instrument;

each set of gas path switching mechanism is arranged between the gas chromatograph and one set of underground gas transmission mechanism;

the gas chromatograph is communicated with the rotating shaft air passages in the two sets of gas path switching mechanisms through the two first channel pipelines;

two gas input ends of the differential pressure measuring instrument are respectively communicated with the rotating shaft gas passages in the two sets of gas path switching mechanisms through a second vent pipeline, and a second valve is arranged on the second vent pipeline.

The technical scheme of the invention also provides a goaf gas monitoring method, and the mining monitoring equipment adopting any one of the technical schemes comprises the following steps:

s01: a gas chromatograph, an underground gas transmission mechanism and a gas circuit switching mechanism are arranged in advance, so that an air inlet head is positioned in a goaf;

s02: gas transmitted from each air inlet head is monitored and analyzed by a gas chromatograph at regular time every day, and the rotating disc is driven to rotate by a driving mechanism so as to realize air path switching;

s03: and the gas chromatograph transmits the gas data to the control processing equipment, and the control processing equipment processes and stores the daily gas data of each gas inlet head.

Further, the goaf gas monitoring method also comprises the following steps:

the pressure difference of the gas transmitted from the two air inlet heads in the two sets of air path switching mechanisms is monitored by a pressure difference measuring instrument every day at regular time, the pressure difference is transmitted to a control processing device, and the control processing device processes and stores the pressure difference of every two air inlet heads every day.

By adopting the technical scheme, the method has the following beneficial effects:

the mining monitoring equipment and the goaf gas monitoring method provided by the invention can be used for monitoring gas in the goaf on site, can realize automatic gas circuit switching through the gas circuit switching mechanism, can be used for analyzing the gas in each monitoring point by a gas chromatograph, can be used for monitoring the pressure difference or energy level of the two monitoring points by arranging the pressure difference measuring instrument, are convenient to operate, and can provide more accurate monitoring results for goaf air leakage and residual coal spontaneous combustion research.

Drawings

Fig. 1 is a schematic diagram of a mine monitoring device provided in an embodiment of the invention;

FIG. 2 is a schematic view of the connection of the inlet header to the secondary pipe;

FIG. 3 is a schematic view of the inlet end of the inlet head being spherical;

FIG. 4 is a schematic view of the gas path switching mechanism being turned off;

FIG. 5 is a schematic diagram of the air path switching mechanism being turned on;

FIG. 6 is a cross-sectional view of the rotating disk shaft and seal head;

FIG. 7 is a schematic structural view of the telescopic docking device;

FIG. 8 is a schematic view of a mounting plate having a plurality of mounting plate through holes;

FIG. 9 is a schematic view of the meshing of the turntable gear on the turntable with the drive gear;

FIG. 10 is a cross-sectional view of the rotary disk along the rotary disk air passages;

FIG. 11 is a schematic view of the communication connections of the control processing device, the gas chromatograph, the differential pressure gauge, the piston, and the stepper motor;

fig. 12 is a schematic view of gas monitoring of a gob using a mining monitoring device.

Detailed Description

The following further describes embodiments of the present invention with reference to the accompanying drawings. In which like parts are designated by like reference numerals. It should be noted that the terms "front," "back," "left," "right," "upper" and "lower" used in the following description refer to directions in the drawings, and the terms "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.

As shown in fig. 1 to 12, a mining monitoring device according to an embodiment of the present invention includes a gas chromatograph 1, a downhole gas transmission mechanism 2, and a gas circuit switching mechanism 3.

The downhole gas transmission mechanism 2 comprises a protection tube 21, a plurality of gas inlet heads 22 arranged on the protection tube 21, and a plurality of gas delivery pipes 23 in the protection tube 21, wherein each gas inlet head 22 is connected with one gas delivery pipe 23.

The air passage switching mechanism 3 includes a box 31 having an air outlet 311, a fixed disk 32 disposed in the box 31, a rotary disk 33 disposed in the box 31, and a driving mechanism 36 disposed in the box 31 and used for driving the rotary disk 33 to rotate.

The fixed disk 32 is provided with a plurality of fixed disk vent holes 321, and each gas delivery pipe 23 is connected with one fixed disk vent hole 321.

The rotary disk 33 is provided with one rotary disk ventilating hole 331 and a plurality of rotary disk ventilating holes 332.

Wherein, when the rotary disk vent holes 331 are in butt communication with one of the fixed disk vent holes 321, each of the remaining fixed disk vent holes 321 is in butt communication with one of the rotary disk vent holes 332, respectively.

A rotary shaft air passage 341 is provided on the rotary shaft 34 of the rotary disk 33, and a rotary disk air passage 333 for communicating the rotary shaft air passage 341 with the rotary disk vent hole 331 is provided in the rotary disk 33.

The end of the rotating disc rotating shaft 34 is provided with a sealing end cover 35, the gas chromatograph 1 is communicated with the rotating shaft air passage 341 through a first vent pipeline 11, and the first vent pipeline 11 is provided with a first valve 12.

The mining monitoring equipment provided by the embodiment of the invention is mainly used for monitoring and analyzing the gas in the goaf.

The mining monitoring equipment comprises a gas chromatograph 1, an underground gas transmission mechanism 2 and a gas circuit switching mechanism 3.

The gas chromatograph 1 is an apparatus for qualitatively and quantitatively analyzing a complex mixture of multiple components by using a chromatographic separation technique and a detection technique.

The downhole gas transfer mechanism 2 is used to be disposed in the return air lane 101 and/or the haulage lane 102 on both sides of the work surface 100 to extend toward the gob 200 so that the intake head 22 can be disposed in the gob 200 to collect gas.

The downhole gas transmission mechanism 2 comprises a protection pipe 21, a plurality of gas inlet heads 22 and a plurality of gas delivery pipes 23.

The protection tube 21 is a metal tube and plays a role in protection. A plurality of gas inlet heads 22 are mounted on the protection pipe 21 at intervals, a plurality of gas conveying pipes 23 are arranged in the protection pipe 21, and each gas inlet head 22 is connected with one gas conveying pipe 23, so that the gas of the gas inlet head 22 of each monitoring point is independently transmitted.

The gas path switching mechanism 3 is arranged between the gas chromatograph 1 and the downhole gas transmission mechanism 2, and is used for realizing gas path switching, so that only one gas inlet 22 is transmitted to the gas chromatograph 1 at a time for analysis.

The air passage switching mechanism 3 includes a case 31, a fixed disk 32, a rotating disk 33, and a driving mechanism 36.

The tank 31 has a cavity therein, and the tank 31 has an exhaust port 311 communicating with the cavity.

The fixed tray 32 is fixedly mounted in the case 31, and the fixed tray 32 has a plurality of fixed tray ventilation holes 321 that penetrate therethrough. A plurality of fixed disk ventilation holes 321 are evenly distributed on the fixed disk 32 along the circumferential direction.

The number of the fixed disk vent holes 321 corresponds to the number of the gas inlets 22, each gas inlet 22 is connected with one fixed disk vent hole 321 through one gas delivery pipe 23, and the gas collected by each gas inlet 22 can be provided to the gas chromatograph 1 through one fixed disk vent hole 321.

The rotary disk 33 is arranged in the box body 31, a rotary disk rotating shaft 34 of the rotary disk 33 is rotatably arranged on the box body 31, and one end of the rotary disk rotating shaft 34 extends out of the box body 31. The rotary disk 33 rotates integrally with the rotary disk rotating shaft 34. The rotating disc shaft 34 may be mounted on the case 31 through a bearing.

The rotary disk 33 has a rotary disk vent hole 331 and a plurality of rotary disk vent holes 332. A rotary disk ventilating hole 331 and a plurality of rotary disk exhausting holes 332 are uniformly distributed on the rotary disk 33 in the circumferential direction.

The number of the rotary disk vent holes 331 and the rotary disk vent holes 332 is equal to the number of the fixed disk vent holes 321.

The rotary disk vent hole 331 is a blind hole provided on the rotary disk 33. The rotary disk discharge hole 332 penetrates the rotary disk 33, and communicates with the cavity of the case 31.

The rotary disk 33 has a rotary disk air passage 333 therein, and the rotary disk rotary shaft 34 has a rotary shaft air passage 341 therein. The rotary disk air passage 333 communicates between the rotary disk vent hole 331 and the rotation shaft air passage 341. The end of the rotating disc rotating shaft 34 facing the fixed disc 32 is a sealed end, and the end of the rotating disc rotating shaft outside the box 31 is provided with a sealed end cover 35, and the sealed end cover 35 is provided with a first joint 351. The gas chromatograph 1 is connected to the first joint 351 through the first vent pipe 11.

The driving mechanism 36 is disposed in the housing 31, and an output end thereof is connected to the rotary disk 33 or the rotary disk rotating shaft 34 for driving the rotary disk 33 to rotate.

Each actuation of the drive mechanism 36 causes the rotary disc 33 to rotate through an angle alpha. If the number of the fixed disk vent holes 321 is n, and n is a natural number equal to or greater than 3, α is 360 °/n. The fixed disk 32 is arranged coaxially with the rotary disk 33. The fixed disk vent holes 321, the rotating disk vent holes 331 and the rotating disk vent holes 332 have the same radius, and the radius is r. The distance between the center of the fixed disk vent hole 321 and the center of the fixed disk 32, the distance between the center of the rotary disk vent hole 331 and the center of the rotary disk 33, and the distance between the center of the rotary disk exhaust hole 332 and the center of the rotary disk 33 are equal to R, respectively.

Each time the drive mechanism 36 is driven, the rotary disk vent holes 331 are in abutting communication with one of the fixed disk vent holes 321, and each of the remaining fixed disk vent holes 321 is in abutting communication with one of the rotary disk vent holes 332. Only one gas collected by the gas inlet head 22 is supplied to the gas chromatograph 1 for analysis through the gas delivery pipe 23, the fixed disk vent hole 321, the rotating disk gas passage 333, the rotating shaft gas passage 341, and the first vent pipe 11 at a time. The remaining gas collected in the gas inlet header 22 is discharged through the corresponding gas delivery pipe 23, the fixed disk vent hole 321, the rotating disk discharge hole 332, and the gas discharge hole 311.

The gas chromatograph 1 may transmit the data of the gas analysis to the control processing device 5 for processing and storage. The control processing device 5 may be a computer. According to the requirement, a warning value of the oxygen content can be preset in the control processing equipment 5, when the oxygen content of the data transmitted from the gas chromatograph 1 exceeds the warning value, warning is sent to constructors, including information warning, sound warning and the like, the fact that the goaf has the risk of spontaneous combustion of coal is indicated, and air leakage prevention operation and fire prevention and extinguishing preparation work are required to be carried out on the goaf.

The driving mechanism 36 can be controlled by the control processing device 5, a controller is arranged in the driving mechanism 36, the control processing device 5 is in communication connection with the controller in the driving mechanism 36, signals can be sent to the controller according to user setting, the driving mechanism 36 automatically drives the rotating disc 33 to rotate, air path switching is achieved, manual air path switching is not needed, and operation is convenient.

A sealing ring or a sealing ring is arranged between the sealing end cover 35 and the end part of the rotating disc rotating shaft 34, the sealing end cover 35 can rotate relative to the rotating disc rotating shaft 34, when the rotating disc rotating shaft 34 and the rotating disc 33 integrally rotate, the sealing end cover 35 can be kept not to rotate, so that the first joint 351 on the sealing end cover does not rotate, the first ventilation pipeline 11 does not need to rotate along with the rotating disc 33, and the connection of pipelines is facilitated.

In one embodiment, as shown in fig. 4-5, the rotary disk ventilating holes 331 and each of the rotary disk ventilating holes 332 are provided with a telescopic docking unit 37 capable of docking and undocking with and undocking from the fixed disk ventilating holes 321.

The provision of the telescopic docking means 37 ensures that both the rotary disk vent holes 331 and the rotary disk vent holes 332 can be docked with the fixed disk vent holes 321. The telescopic docking device 37 can be controlled automatically by the control processing device 5.

In one embodiment, as shown in fig. 7, the telescopic docking unit 37 includes a fixed sleeve 371 fixedly mounted on the rotary disk 33 and a sliding sleeve 372 slidably coupled to the fixed sleeve 371.

A piston 373 for driving the sliding sleeve 372 to extend and retract is provided between the fixed sleeve 371 and the sliding sleeve 372.

A sealing ring may be provided at the end of the sliding sleeve 372 to sealingly interface with the stationary disk vent 321, as desired.

Each piston 373 has a controller, the control processing device 5 is in communication connection with the controllers in the pistons 373, signals can be sent to the controllers according to user settings, the pistons 373 automatically drive the sliding sleeves 372 to extend and retract, manual butt joint and separation operation is not needed, and operation is convenient.

In one embodiment, as shown in fig. 4-5 and 9-10, the drive mechanism 36 includes a stepper motor 361 and a drive gear 362.

The gear rotation shaft 363 of the transmission gear 362 is installed in the case 31 through a bracket 364.

An output shaft of the stepping motor 361 is connected to the gear rotation shaft 363.

A rotary disk gear 334 is provided on the outer peripheral surface of the rotary disk 33, and the rotary disk gear 334 is meshed with the transmission gear 362.

The transmission ratio of the transmission gear 362 to the rotating disk gear 334 is K, and the angle of each rotation of the stepping motor 361 can be preset to be α/K according to actual needs, so that the stepping motor 361 rotates to enable the rotating disk 33 to rotate by α in sequence.

In one embodiment, as shown in fig. 1-2, the protection pipe 21 includes a main pipe 211 for being disposed in the roadway and a sub pipe 212 for being placed in the gob 200, the sub pipe 212 being connected to the main pipe 211 in an L-shape. The inlet header 22 is mounted on the secondary pipe 212.

The main pipe 211 is intended to be arranged in a roadway, for example in the return air roadway 101 and/or the haulage roadway 102. The secondary tube 212 is for disposition in the gob 200. The sub-pipe 212 is formed in an L shape integrally with the main pipe 211, and the intake head 22 is installed on the sub-pipe 212 to facilitate arrangement and collection of gas in the gob 200.

The position of each inlet header 22 may be set in advance on the secondary pipe 212 according to the position of the actual monitoring point.

In one embodiment, as shown in fig. 2-3, the intake head 22 includes an intake end 221 and a connection end 222 connected to the intake end 221. The connection end 222 is in the secondary pipe 212, and the gas delivery pipe 23 is connected to the connection end 222. The air inlet end 221 is located outside the secondary pipe 212, and a plurality of air inlets 223 are provided on the air inlet end 221.

According to the requirement, a filter screen can be arranged on the air inlet 223 to prevent impurities from entering.

In one embodiment, as shown in FIG. 3, the gas inlet end 222 is spherical, has high structural strength, and can be disposed with more gas inlets 223, for example, to collect gas in the gob 200.

In one embodiment, as shown in fig. 1, the mining monitoring device comprises two sets of downhole gas transmission mechanisms 2, two sets of gas circuit switching mechanisms 3 and one differential pressure measuring instrument 4.

Each set of gas path switching mechanism 3 is arranged between the gas chromatograph 1 and one set of underground gas transmission mechanism 2.

The gas chromatograph 1 is communicated with the rotating shaft air passages 341 in the two sets of air passage switching mechanisms 3 through the two first passage pipelines 11.

Two gas input ends 40 of the differential pressure measuring instrument 4 are respectively communicated with the rotating shaft gas passages 341 in the two sets of gas path switching mechanisms 3 through a second gas passage 41, and a second valve 42 is arranged on the second gas passage 41.

In this embodiment, the pressure difference between each two monitoring points in the two sets of downhole gas transmission mechanisms 2 can be measured by the pressure difference measuring instrument 4, so that an operator can know the pressure or energy position distribution of the goaf. The differential pressure measuring instrument 4 can transmit the air pressure difference at each two monitoring points to the control processing device 5 for processing and storage.

According to the requirement, a critical value of the air pressure difference can be preset in the control processing equipment 5, and when the air pressure difference between two or more monitoring points exceeds the critical value in the data transmitted from the pressure difference measuring instrument 4, warning including information warning, sound warning and the like is sent to constructors to indicate that air leakage prevention operation needs to be carried out on the goaf.

The goaf gas monitoring method provided by the embodiment of the invention adopts the mining monitoring equipment of any one of the embodiments, and comprises the following steps:

s01: the gas chromatograph 1, the downhole gas transmission mechanism 2, and the gas passage switching mechanism 3 are arranged in advance such that the intake head 22 is in the gob 200.

S02: the gas transmitted from each gas inlet 22 is monitored and analyzed by the gas chromatograph 1 at regular time every day, and the rotating disc 33 is driven to rotate by the driving mechanism 36 to realize gas path switching.

S03: the gas chromatograph 1 transmits the gas data to the control processing device 5, and the control processing device 5 processes and stores the daily gas data for each gas inlet head 22.

The control processing device 5 is preset with a warning value of oxygen content, and when the oxygen content of the data transmitted from the gas chromatograph 1 exceeds the warning value, warnings including information warning, sound warning and the like are sent to constructors, which indicate that the goaf has the risk of spontaneous combustion of coal, and air leakage prevention operation and fire prevention and extinguishing preparation operation are required to be carried out on the goaf.

In one embodiment, the goaf gas monitoring method further comprises the following steps:

the pressure difference of the gas transmitted from the two gas inlets 22 in the two sets of gas path switching mechanisms 2 is monitored by the pressure difference measuring instrument 4 at regular time every day, the pressure difference is transmitted to the control processing equipment 5, and the control processing equipment 5 processes and stores the daily pressure difference of every two gas inlets 22.

The control processing equipment 5 is preset with a critical value of air pressure difference, and when the air pressure difference between two or more monitoring points exceeds the critical value in the data transmitted from the pressure difference measuring instrument 4, warnings including information warning, sound warning and the like are sent to constructors to indicate that air leakage prevention operation needs to be carried out on the goaf.

According to the needs, the above technical schemes can be combined to achieve the best technical effect.

The foregoing is considered as illustrative only of the principles and preferred embodiments of the invention. It should be noted that, for those skilled in the art, several other modifications can be made on the basis of the principle of the present invention, and the protection scope of the present invention should be regarded.