On-demand closing device and method for goaf gas extraction branch opening

Abstract

According to the goaf gas extraction branch opening on-demand closing device and method, an air bag adheres to the interior of an extraction branch pipe and is connected with an inflation pipeline, when the gas concentration in an extraction header pipe is smaller than a preset value, a gas concentration sensor connected to the exterior of the extraction header pipe feeds back to a control unit through a signal line, the control unit opens a pneumatic valve, and the gas extraction branch opening is closed. The nitrogen cylinder inflates the air bag, and the air bag expands, so that the gas extraction branch opening is closed. And after closing, if the gas concentration in the gas extraction header pipe is still lower than the preset value, continuously and automatically executing the operation until the gas concentration in the gas extraction header pipe is greater than or equal to the preset value. The goaf gas extraction branch opening can be closed according to needs, the goaf gas extraction effect is improved, the possibility of upper corner gas overrun or gas disasters is reduced, energy consumption of a gas extraction pump is reduced, and gas resource development is promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine safety, and in particular relates to an on-demand closing device and method for gas extraction branch openings in goaf areas. Background Art

[0002] Coal resources are one of my country's important energy resources. During the coal mining process, some coal bodies are left behind due to the limitations of coal mining technology and ground protection facilities. As the coal mining face advances, the coal seam roof gradually collapses, and the remaining coal is buried in the goaf, where the remaining coal in the goaf undergoes gas desorption. In addition, gas in the adjacent layers will also flow into the goaf after the coal seam is depressurized. Under the action of wind flow, gas in the goaf flows toward the upper corners, which is particularly prone to causing gas exceeding the limit in the upper corners or gas disasters. Therefore, avoiding gas accumulation in the upper corners during coal mining can effectively reduce the possibility of gas disasters.

[0003] Upper corner gas extraction is an effective technical measure for gas control in goafs. Upper corner gas extraction generally adopts the technology of burying pipes in goafs, by laying a gas extraction main pipe in the goaf, and setting branch ports on the gas extraction main pipe to extract gas in the goaf. Studies have shown that as the coal mining face advances, the farther the goaf is from the coal mining face, the lower the gas concentration. Therefore, for goafs far away from the coal mining face, if gas extraction is carried out all the time, on the one hand, the loss of negative pressure along the way will be greatly increased, and on the other hand, the gas extraction efficiency of goafs close to the coal mining face will also be reduced, ultimately resulting in low extraction efficiency of the gas extraction main pipe in the entire goaf. Therefore, a device and method for closing the gas extraction branch ports in the goaf on demand is needed. Summary of the invention

[0004] The purpose of the present invention is to provide a device and method for closing a gas extraction branch port in a goaf on demand, which can close the gas extraction branch port on demand. By adhering an air bag in the extraction branch pipe, the air bag is connected to the inflation pipeline. When the gas concentration in the extraction main pipe is less than a predetermined value, the gas concentration sensor connected to the outside of the extraction main pipe feeds back to the control unit through a signal line. The control unit opens the pneumatic valve, and the inflation pipeline inflates the air bag. The air bag expands to achieve the closure of the gas extraction branch port. After closing, if the gas concentration in the gas extraction main pipe is still lower than the predetermined value, the above operation will continue to be automatically performed until the gas concentration in the gas extraction main pipe is greater than or equal to the predetermined value.

[0005] To achieve the above object, the present invention adopts the following technical solution: A device for closing gas extraction branches in goafs on demand, comprising a closing unit, an air charging unit, a first extraction branch pipe, a second extraction branch pipe, an extraction main pipe and a control unit, wherein the first extraction branch pipe and the second extraction branch pipe are both provided with closing units of the same structure, and the closing unit comprises an air bag, a first filter screen and a second filter screen, wherein the air bag is arranged on the inner wall of the extraction branch pipe, the first filter screen is arranged above the air bag, and the second filter screen is arranged below the air bag; The inflation unit includes a nitrogen cylinder, a pressure regulating valve, a first pressure sensor, a second pressure sensor, a first three-way joint, a second three-way joint, and a third three-way joint. The nitrogen cylinder is connected to the pressure regulating valve through an inflation pipeline, the pressure regulating valve is connected to the right end of the first three-way joint through the inflation pipeline, the upper end of the first three-way joint is connected to the right end of the second three-way joint through the inflation pipeline, the left end of the first three-way joint is connected to the right end of the third three-way joint through the inflation pipeline, the lower port of the second three-way joint is provided with a first pressure sensor, the first pressure sensor is connected to the control unit through a signal line, the left end of the second three-way joint is connected to the first pneumatic valve through the inflation pipeline, the first pneumatic valve is connected to the airbag of the closing unit in the first extraction branch pipe through the inflation pipeline, the upper port of the third three-way joint is provided with a second pressure sensor, the second pressure sensor is connected to the control unit through a signal line, the left end of the third three-way joint is connected to the second pneumatic valve through the inflation pipeline, and the second pneumatic valve is connected to the airbag of the closing unit in the second extraction branch pipe through the inflation pipeline; The control unit includes a PLC controller and a plurality of methane concentration sensors. The methane concentration sensors are arranged on the outer wall of the extraction main pipe, and the methane concentration sensor signals are connected to the PLC controller.

[0006] The extraction main pipe is connected to the extraction pump.

[0007] The main gas extraction pipe includes several gas extraction pipes, and adjacent gas extraction pipes are connected by flanges.

[0008] The method for closing the gas extraction branch opening in the goaf on demand is implemented based on the above-mentioned device for closing the gas extraction branch opening in the goaf on demand, and comprises the following steps: (1) Turn on the extraction pump to carry out extraction work, keep the airbags of each closed unit in an uninflated state, and set the minimum predetermined value of the gas concentration in the extraction main pipe through the control unit; (2) As the extraction work proceeds, when the methane concentration sensor monitors that the gas concentration in the extraction main pipe is less than the minimum preset value, the control unit sends a command to the first pressure sensor through the signal line, and the first pressure sensor controls the first pneumatic valve to open, and the nitrogen cylinder inflates the air bag in the first extraction branch pipe through the inflation pipeline until the air bag expands and completely blocks the first extraction branch pipe; (3) As the extraction work proceeds, the coal mining face moves forward. When the methane concentration sensor again detects that the gas concentration in the extraction main pipe is less than the minimum preset value, the control unit sends a command to the second sensor through the signal line. The second sensor controls the second pneumatic valve to open, and the nitrogen bottle inflates the air bag in the second extraction branch pipe through the inflation pipeline until the air bag expands and completely blocks the second extraction branch pipe.

[0009] As the coal mining face continues to advance, the area of ​​the goaf gradually increases, and more extraction branch pipes need to be installed in the goaf. A closing unit is installed in each extraction branch pipe, and each closing unit is connected to the nitrogen cylinder through an inflation pipeline and a pneumatic valve. If the methane concentration sensor again detects that the gas concentration is lower than the minimum preset value, the control unit will inflate the air bag to block the extraction branch pipes one by one until the coal mining is completed.

[0010] Compared with the prior art, the present invention has outstanding substantive features and significant progress. Specifically, the present invention adheres an airbag in the extraction branch pipe, and the airbag is connected to the inflation pipeline. When the gas concentration in the extraction main pipe is less than a predetermined value, the gas concentration sensor connected to the outside of the extraction main pipe feeds back to the control unit through a signal line, and the control unit opens the pneumatic valve, and the inflation pipeline inflates the airbag, and the airbag expands to achieve the closure of the gas extraction branch. After closing, if the gas concentration in the gas extraction main pipe is still lower than the predetermined value, the above operation continues to be automatically performed until the gas concentration in the gas extraction main pipe is greater than or equal to the predetermined value.

[0011] To sum up, the present application can realize the on-demand closure of gas extraction branches in goafs, improve the gas extraction effect in goafs, reduce the possibility of excessive gas in the upper corners or gas disasters, reduce the energy consumption of gas extraction pumps, and promote the development of gas resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the on-demand closing device of the present invention.

[0013] Figure 2 yes Figure 1 Enlarged view of part A in the middle.

[0014] Figure 3 yes Figure 1 Enlarged view of part B in the middle. DETAILED DESCRIPTION

[0015] The embodiments of the present invention are further described below with reference to the accompanying drawings.

[0016] Embodiment 1 like Figure 1-3As shown, the on-demand closing device for gas extraction branch ports in goaf includes a closing unit, an air charging unit, a first extraction branch pipe 2, a second extraction branch pipe 3, an extraction main pipe 1 and a control unit. Closing units with the same structure are arranged in the first extraction branch pipe 2 and the second extraction branch pipe 3. The closing unit includes an air bag 4, a first filter screen 5 and a second filter screen 6. The air bag 4 is arranged on the inner wall of the extraction branch pipe, the first filter screen 5 is arranged above the air bag 4, and the second filter screen 6 is arranged below the air bag 4. The inflation unit includes a nitrogen cylinder 7, a pressure regulating valve 11, a first pressure sensor 12, a second pressure sensor 13, a first three-way joint 8, a second three-way joint 9, and a third three-way joint 10. The nitrogen cylinder 7 is connected to the pressure regulating valve 11 through an inflation pipeline, the pressure regulating valve 11 is connected to the right end of the first three-way joint 8 through the inflation pipeline, and the upper end of the first three-way joint 8 is connected to the right end of the second three-way joint 9 through the inflation pipeline. The left end of the first three-way joint 8 is connected to the right end of the third three-way joint 10 through an air charging pipeline, the lower end of the second three-way joint 9 is provided with a first pressure sensor 12, the first pressure sensor 12 is connected to the control unit through a signal line, the left end of the second three-way joint 9 is connected to the first pneumatic valve 14 through an air charging pipeline, the first pneumatic valve 14 is connected to the air bag 4 of the closing unit in the first extraction branch pipe 2 through the air charging pipeline, the upper end of the third three-way joint 10 is provided with a second pressure sensor 13, the second pressure sensor 13 is connected to the control unit through a signal line, the left end of the third three-way joint 10 is connected to the second pneumatic valve 15 through an air charging pipeline, and the second pneumatic valve 15 is connected to the air bag 4 of the closing unit in the second extraction branch pipe 3 through the air charging pipeline; The control unit includes a PLC controller 24 and a plurality of methane concentration sensors 16. The methane concentration sensors 16 are arranged on the outer wall of the extraction main pipe 1. The methane concentration sensors 16 are connected to the PLC controller 24 through a signal line. The extraction main pipe 1 is connected to the extraction pump 23. The extraction main pipe 1 includes a plurality of gas extraction pipes 17, and adjacent gas extraction pipes 17 are connected by flanges 18. As the coal mining face 19 advances in the direction of arrow 20, the coal seam roof gradually collapses, and the remaining coal is buried in the goaf 21. The remaining coal in the goaf 21 undergoes a gas desorption effect. In addition, the gas in the adjacent layers will also flow into the goaf 21 after the coal seam is depressurized. The gas in the goaf 21 flows out to the upper corner 22 under the action of the wind flow, which is particularly prone to causing the gas in the upper corner 22 to exceed the limit or cause a gas disaster accident. Therefore, it is necessary to extract gas from the goaf 21. However, as the length of the goaf 21 gradually extends in the direction of arrow 20, more and more extraction branch pipes are buried in the goaf 21. As the extraction time increases, the gas concentration and flow rate of the extraction branch pipes far away from the coal mining face 19 gradually decrease, affecting the gas extraction effect of the extraction main pipe 1, and also greatly wasting manpower, material and financial resources.

[0017] Embodiment 2 The method for closing the gas extraction branch opening in the goaf on demand is implemented based on the device for closing the gas extraction branch opening in the goaf on demand described in the first embodiment, and comprises the following steps: (1) Turn on the extraction pump 23 to perform extraction work, keep the airbag 4 of each closed unit in an uninflated state, and set the minimum preset value of the gas concentration in the extraction main pipe 1 through the control unit. The minimum preset value is set by the engineering technicians; (2) As the extraction work proceeds, when the methane concentration sensor 16 detects that the gas concentration in the extraction main pipe 1 is less than the minimum preset value, the control unit sends a command to the first pressure sensor 12 through the signal line, and the first pressure sensor 12 controls the first pneumatic valve 14 to open, and the nitrogen cylinder 7 inflates the air bag 4 in the first extraction branch pipe 2 through the inflation pipeline until the air bag 4 expands and completely blocks the first extraction branch pipe 2; (3) As the extraction work proceeds, the coal mining face 19 moves forward. When the methane concentration sensor 16 detects again that the gas concentration in the extraction main pipe 1 is less than the minimum preset value, the control unit sends a command to the second sensor through the signal line. The second sensor controls the second pneumatic valve 15 to open, and the nitrogen bottle 7 inflates the air bag 4 in the second extraction branch pipe 3 through the inflation pipeline until the air bag 4 expands and completely blocks the second extraction branch pipe 3.

[0018] As the coal mining face 19 continues to advance, the area of ​​the goaf 21 gradually increases, and more extraction branch pipes need to be set in the goaf 21. A closing unit is set in each extraction branch pipe, and each closing unit is connected to the nitrogen bottle 7 through an air filling pipeline and a pneumatic valve. If the methane concentration sensor 16 detects that the gas concentration is less than the minimum preset value again, the control unit will inflate the airbag 4 to block the extraction branch pipes one by one until the coal mining is completed. When the number of extraction branch pipes is n, the first three-way connector 8 is the first (n+1) connector, and the first (n+1) connector is connected to n pipelines, each pipeline is connected to a three-way, and the upper port or the lower port of the three-way is connected to a pressure sensor, and the pressure sensor is connected to the control unit through a signal line, and the left port of the three-way is connected to the pneumatic valve, and the pneumatic valve is connected to the closing unit through a pipeline. As the coal mining face 19 advances in the direction of arrow 20, the hydraulic support gradually moves in the direction of arrow 20, and the next extraction branch pipe is gradually buried in the goaf 21. When the gas concentration in the extraction main pipe 1 is less than a predetermined value (the predetermined value is determined by engineering and technical personnel), the above steps are repeated until the coal mining is completed. The present invention adheres an air bag 4 in the extraction branch pipe, and the air bag 4 is connected to the inflation pipeline. When the gas concentration in the extraction main pipe 1 is less than the predetermined value, the gas concentration sensor connected to the outside of the extraction main pipe 1 is fed back to the control unit through the signal line, and the control unit opens the pneumatic valve, and the inflation pipeline inflates the air bag 4, and the air bag 4 expands to achieve the closure of the gas extraction branch port. After closing, if the gas concentration in the gas extraction main pipe 1 is still lower than the predetermined value, the above operation continues to be automatically performed until the gas concentration in the gas extraction main pipe 1 is greater than or equal to the predetermined value. When closing the extraction branch pipe, the gas extraction branch openings in the gas extraction main pipe 1 of the goaf 21 are closed one by one from far to near, so that the gas concentration of the gas extraction main pipe 1 is greater than or equal to a predetermined value; In summary, the present application can realize the on-demand closure of the gas extraction branch in the goaf, improve the gas extraction effect in the goaf 21, reduce the possibility of gas exceeding the limit or gas disaster in the upper corner 22, reduce the energy consumption of the gas extraction pump 23, and promote the development of gas resources.

[0019] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. Any modification or partial replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. The on-demand closing device for gas extraction branch openings in goaf areas is characterized by: It includes a closing unit, an air filling unit, a first extraction branch pipe, a second extraction branch pipe, an extraction main pipe and a control unit. The first extraction branch pipe and the second extraction branch pipe are both provided with closing units with the same structure. The closing unit includes an air bag, a first filter screen and a second filter screen. The air bag is arranged on the inner wall of the extraction branch pipe, the first filter screen is arranged above the air bag, and the second filter screen is arranged below the air bag. The inflation unit includes a nitrogen cylinder, a pressure regulating valve, a first pressure sensor, a second pressure sensor, a first three-way joint, a second three-way joint, and a third three-way joint. The nitrogen cylinder is connected to the pressure regulating valve through a charging pipeline, the pressure regulating valve is connected to the right end of the first three-way joint through the charging pipeline, the upper end of the first three-way joint is connected to the right end of the second three-way joint through the charging pipeline, the left end of the first three-way joint is connected to the right end of the third three-way joint through the charging pipeline, the lower port of the second three-way joint is provided with a first pressure sensor, the first pressure sensor is connected to the control unit through a signal line, the left end of the second three-way joint is connected to the first pneumatic valve through the charging pipeline, the first pneumatic valve is connected to the airbag of the closing unit in the first extraction branch pipe through the charging pipeline, the upper port of the third three-way joint is provided with a second pressure sensor, the second pressure sensor is connected to the control unit through a signal line, the left end of the third three-way joint is connected to the second pneumatic valve through the charging pipeline, and the second pneumatic valve is connected to the airbag of the closing unit in the second extraction branch pipe through the charging pipeline; The control unit includes a PLC controller and a plurality of methane concentration sensors. The methane concentration sensors are arranged on the outer wall of the extraction main pipe, and the methane concentration sensors are connected to the PLC controller through a signal line.

2. The on-demand closing device for gas extraction branch openings in goaf according to claim 1 is characterized in that: The extraction main pipe is connected to the extraction pump.

3. The on-demand closing device for gas extraction branch openings in goaf according to claim 1 is characterized in that: The main gas extraction pipe includes several gas extraction pipes, and adjacent gas extraction pipes are connected by flanges.

4. A method for closing a gas extraction branch opening in a goaf on demand, implemented based on the device for closing a gas extraction branch opening in a goaf on demand as claimed in any one of claims 1 to 3, characterized in that: The steps include: (1) Turn on the extraction pump to carry out extraction work, keep the airbags of each closed unit in an uninflated state, and set the minimum predetermined value of the gas concentration in the extraction main pipe through the control unit; (2) As the extraction work proceeds, when the methane concentration sensor monitors that the gas concentration in the extraction main pipe is less than the minimum preset value, the control unit sends a command to the first pressure sensor through the signal line, and the first pressure sensor controls the first pneumatic valve to open, and the nitrogen cylinder inflates the air bag in the first extraction branch pipe through the inflation pipeline until the air bag expands and completely blocks the first extraction branch pipe; (3) As the extraction work proceeds, the coal mining face moves forward. When the methane concentration sensor again detects that the gas concentration in the extraction main pipe is less than the minimum preset value, the control unit sends a command to the second sensor through the signal line. The second sensor controls the second pneumatic valve to open, and the nitrogen bottle inflates the air bag in the second extraction branch pipe through the inflation pipeline until the air bag expands and completely blocks the second extraction branch pipe.

5. The method for closing the gas extraction branch opening in the goaf as required according to claim 4 is characterized in that: As the coal mining face continues to advance, the area of ​​the goaf gradually increases, and more extraction branch pipes need to be installed in the goaf. A closing unit is installed in each extraction branch pipe, and each closing unit is connected to the nitrogen cylinder through an inflation pipeline and a pneumatic valve. If the methane concentration sensor again detects that the gas concentration is lower than the minimum preset value, the control unit will inflate the air bag to block the extraction branch pipes one by one until the coal mining is completed.

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