An automatic pressure equalization device and method for an airtight coal roadway

Abstract

The present invention discloses an automatic pressure equalization device for a sealed coal roadway, which is installed in the coal roadway. There is a sealed wall in the coal roadway, and the end of the coal roadway is a goaf. There is a space between the sealed wall and the goaf. The automatic pressure equalization device for the sealed coal roadway includes a telescopic nitrogen storage device, a pressure airbag, a first pressure sensor, a second pressure sensor, a fixing frame, a nitrogen generator, a U-shaped drainage trough, a drainage pipe, a first solenoid valve, a second solenoid valve, an electromagnetic check valve, an air inlet pipeline, and an injection pipeline. The present invention also provides an automatic pressure equalization method for a sealed coal roadway. The automatic pressure equalization device for the sealed coal roadway of the present invention can realize automatic pressure equalization in the goaf, balance the internal and external pressures, and inhibit the oxidation and spontaneous combustion of the residual coal in the goaf; when the gas pressure in the goaf is greater than the gas pressure in the coal roadway area on the front side of the telescopic nitrogen storage device, the escaped gas is discharged into the drainage pipe, reducing the risk of gas accumulation.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mine safety, and particularly relates to an automatic pressure equalization device and method for airtight coal roadways. Background Art

[0002] Air leakage in airtight coal roadways is a harmful factor commonly existing in coal mines. It can not only cause spontaneous combustion of the residual coal in the goaf, but also lead to problems such as gas gushing from the goaf to the front of the wall, resulting in casualties and property losses and threatening the safe production of coal mines.

[0003] At present, the methods for preventing air leakage in the goaf during the mining process mainly include building airtight walls, controlling air leakage by pressure equalization technology, grouting filling, isolating the goaf from the working face, injecting gel in coal pillars to block air leakage channels, etc. These methods have important positive significance for the safe production of coal mines, but due to the complexity of the underground working environment of coal mines and the restriction of technical conditions, using a single means cannot completely prevent air leakage. The reasons are as follows: on the one hand, the pore fissures developed in the coal seam itself and the pore fissures generated inside the coal and rock mass around the coal roadway affected by mining activities enhance the pore connectivity in the coal and rock around the coal roadway, forming air leakage channels; on the other hand, the air pressure in the roadway is affected by the change of the ground atmospheric pressure, resulting in a pressure difference with the gas in the goaf, so that the air leakage prevention effect is not ideal, and there is still a large amount of air seeping into the goaf, causing spontaneous combustion in the goaf. After the coal roadway is sealed, it is usually manually monitored by using a U-shaped tube for the air outlet and inlet of the airtight, which can only observe the pressure situation at a certain time point, but cannot reflect the change of pressure in the continuous goaf with the ground climate and underground environment, and cannot respond immediately to abnormal situations.

[0004] Therefore, in order to take effective measures to reduce the accidents caused by air leakage in the goaf, it is necessary to invent an automatic pressure equalization device and method for airtight coal roadways to prevent oxygen in the fresh air flow from flowing into the goaf, causing oxidation and spontaneous combustion of the coal body, or gas gushing from the goaf to form a harmful gas accumulation area in front of the wall. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide an automatic pressure equalization device and method for airtight coal roadways.

[0006] To achieve the above purpose, the present invention provides the following technical solution: an automatic pressure equalization device for airtight coal roadways, which is installed in the coal roadway. There is an airtight wall in the coal roadway, the end of the coal roadway is the goaf, and there is a space between the airtight wall and the goaf. The automatic pressure equalization device for airtight coal roadways includes a telescopic nitrogen storage device, a pressure airbag, a first pressure sensor, a second pressure sensor, a fixed frame, a nitrogen generator, a U-shaped drainage trough, a drainage pipe, a first solenoid valve, a second solenoid valve, an electromagnetic check valve, an air inlet pipeline, and an injection pipeline;

[0007] The telescopic nitrogen storage device is fixed in the coal roadway through a fixing frame and is located on the front side of the airtight wall. The telescopic nitrogen storage device includes a shell, a slider and a displacement induction switch. A slider that can slide axially along the inside of the shell is arranged inside the shell, and a displacement induction switch is arranged on the inner wall at the end of the shell. The displacement induction switch is used to monitor the moving distance of the slider. The shell is axially arranged inside the fixing frame, and the end of the fixing frame is fixed on the inner wall surface of the coal roadway. A pressure airbag is arranged in the gap between the outside of the fixing frame and the inner wall surface of the coal roadway. An injection pipeline is connected to the air outlet of the shell. The injection pipeline penetrates through the airtight wall and extends into the space between the airtight wall and the goaf, and an electromagnetic check valve is arranged on the injection pipeline; A channel is arranged axially inside the shell, and an intake pipeline is arranged inside the channel. The intake end of the intake pipeline is connected to the nitrogen generator, and the outlet end of the intake pipeline is connected to the air inlet of the shell. A first solenoid valve is arranged on the intake pipeline; A first pressure sensor is arranged in the coal roadway area on the front side of the telescopic nitrogen storage device to monitor the gas pressure in the coal roadway area on the front side of the telescopic nitrogen storage device. A second pressure sensor is arranged in the space between the airtight wall and the goaf to monitor the gas pressure in the space between the airtight wall and the goaf; A U-shaped drainage trough is arranged in the rock stratum below the telescopic nitrogen storage device. The extraction pipe sequentially passes through the U-shaped drainage trough and the airtight wall from the coal roadway in front of the telescopic nitrogen storage device and then penetrates into the space between the airtight wall and the goaf, and a second solenoid valve is installed on the extraction pipe.

[0008] Further, the cross-section of the shell is a rectangular structure, and the front end is an open structure. The slider is a rectangular block and is made of rubber material. Lubricating oil is applied between the slider and the inner wall of the shell.

[0009] Further, the fixing frame includes a hollow rectangular frame body and fixing rods. The rectangular frame body is fixed to the inner wall surface of the coal roadway through a plurality of fixing rods.

[0010] Further, the gap between the pressure airbag and the inner wall surface of the coal roadway is filled with polyurethane foam.

[0011] Further, a gas sensor is also arranged on the extraction pipe, and the gas sensor is electrically connected to the PLC controller.

[0012] Further, the nitrogen generator, displacement induction switch, electromagnetic check valve, first pressure sensor, second pressure sensor, first solenoid valve, and second solenoid valve are all electrically connected to the PLC controller.

[0013] An automatic pressure equalization method for an airtight coal roadway is realized by using the above automatic pressure equalization device for an airtight coal roadway, and specifically includes the following steps:

[0014] The PLC controller controls the electromagnetic check valve to open, the first solenoid valve and the second solenoid valve are both closed, and the displacement induction switch is turned on;

[0015] When the gas pressure P1 in the coal roadway area on the front side of the telescopic nitrogen storage device measured by the first pressure sensor is greater than the gas pressure P2 in the space between the airtight wall and the goaf measured by the second pressure sensor, the nitrogen in the telescopic nitrogen storage device is injected into the space between the airtight wall and the goaf through the injection pipeline until P1 and P2 are balanced. The slider automatically stops sliding, and the electromagnetic check valve ensures that the gas cannot flow back into the telescopic nitrogen storage device. The position of the slider is monitored by the displacement induction switch throughout the process. When the slider slides to an incompressible state, the displacement induction switch is triggered, and then the electromagnetic check valve is closed. The nitrogen generator and the first solenoid valve are opened, and nitrogen is filled into the shell through the inlet pipeline to replenish nitrogen for the telescopic nitrogen storage device until it is full. After the slider returns to its original position, the displacement induction switch is triggered, and the PLC controller closes the nitrogen generator and the first solenoid valve and opens the electromagnetic check valve;

[0016] When the gas pressure P1 in the coal roadway area on the front side of the telescopic nitrogen storage device measured by the first pressure sensor is less than the gas pressure P2 in the space between the airtight wall and the goaf measured by the second pressure sensor, since the electromagnetic check valve is opened, it is ensured that the gas in the space between the airtight wall and the goaf cannot flow back into the telescopic nitrogen storage device. At this time, the PLC controller opens the second solenoid valve on the extraction pipe, sucks the gas in the space between the airtight wall and the goaf into the extraction pipe, and the position of the slider is monitored by the displacement induction switch throughout the process. When it is found that the slider slides, the second solenoid valve on the extraction pipe is immediately closed.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The airtight coal roadway automatic pressure equalization device of the present invention double-guarantees the strict sealing of the coal roadway through the pressure airbag and the polyurethane foaming agent to prevent air leakage through gaps; the airtight coal roadway automatic pressure equalization device of the present invention can realize the automatic pressure equalization of the coal roadway. When the gas pressure in the coal roadway area on the front side of the telescopic nitrogen storage device is greater than the gas pressure in the space between the airtight wall and the goaf, the airtight coal roadway automatic pressure equalization device responds immediately, injects nitrogen into the space between the airtight wall and the goaf through the device to balance the internal and external pressures and inhibit the oxidation and spontaneous combustion of the residual coal in the goaf; when the gas pressure in the adjacent goaf is greater than the gas pressure in the coal roadway area on the front side of the telescopic nitrogen storage device, the escaped gas is discharged into the extraction pipe to reduce the risk of gas accumulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the airtight coal roadway automatic pressure equalization device of the present invention;

[0020] In the figure:

[0021] 1. Housing, 2. Slide block, 3. Displacement induction switch, 4. Pressure airbag, 51. First pressure sensor, 52. Second pressure sensor, 6. Fixing frame, 61. Rectangular frame body, 62. Fixing rod, 7. Nitrogen generator, 8. First solenoid valve, 9. U-shaped drain trough, 10. Extraction pipe, 11. Second solenoid valve, 12. Gas sensor, 13. Electromagnetic check valve, 14. Inlet gas pipeline, 15. Injection gas pipeline;

[0022] 100. Coal roadway; 200. Goaf; 300. Sealing wall. Specific implementation mode

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] Embodiment 1

[0025] Please refer to Figure 1 , a closed coal roadway automatic pressure equalization device, which is installed in the coal roadway 100. There is a sealing wall 300 in the coal roadway 100. The end of the coal roadway 100 is a goaf 200. There is a space between the sealing wall 300 and the goaf 200. The closed coal roadway automatic pressure equalization device includes a telescopic nitrogen storage device, a pressure airbag 4, a first pressure sensor 51, a second pressure sensor 52, a fixing frame 6, a nitrogen generator 7, a U-shaped drain trough 9, an extraction pipe 10, a first solenoid valve 8, a second solenoid valve 11, an electromagnetic check valve 13, an inlet gas pipeline 14, and an injection gas pipeline 15;

[0026] The telescopic nitrogen storage device is fixed in the coal roadway 100 by a fixing frame 6 and is located on the front side of the airtight wall 300. The telescopic nitrogen storage device includes a housing 1, a slider 2, and a displacement induction switch 3. A slider 2 that can slide axially inside the housing 1 is provided inside the housing 1, and a displacement induction switch 3 is provided on the inner wall at the end of the housing 1. The displacement induction switch 3 is used to monitor the moving distance of the slider 2. The housing 1 is axially placed inside the fixing frame 6, and the end of the fixing frame 6 is fixed on the inner wall surface of the coal roadway 100. A pressure airbag 4 is provided in the gap between the fixing frame 6 and the wall of the coal roadway 100. An injection pipeline 15 is connected to the air outlet of the housing 1. The injection pipeline 15 passes through the airtight wall 300 and extends into the space between the airtight wall 300 and the goaf 200, and an electromagnetic check valve 13 is provided on the injection pipeline 15. A channel is provided axially inside the housing 1, and an intake pipeline 14 is provided inside the channel. The intake end of the intake pipeline 14 is connected to a nitrogen generator 7, and the outlet end of the intake pipeline 14 is connected to the air inlet of the housing 1. A first solenoid valve 8 is provided on the intake pipeline 14. A first pressure sensor 51 is provided in the area of the coal roadway 100 on the front side of the telescopic nitrogen storage device to monitor the gas pressure in the area of the coal roadway 100 on the front side of the telescopic nitrogen storage device. A second pressure sensor 52 is provided in the space between the airtight wall 300 and the goaf 200 to monitor the gas pressure in the space between the airtight wall 300 and the goaf 200. A U-shaped drainage trough 9 is provided in the rock stratum below the telescopic nitrogen storage device. The extraction pipe 10 sequentially passes through the U-shaped drainage trough 9 and the airtight wall 300 from the coal roadway 100 on the front side of the telescopic nitrogen storage device and then penetrates into the space between the airtight wall 300 and the goaf 200, and a second solenoid valve 11 is installed on the extraction pipe 10.

[0027] The cross-section of the housing 1 is a rectangular structure, and the front end is an open structure. The slider 2 is a rectangular block and is made of rubber material. Lubricating oil is applied between the slider 2 and the inner wall of the housing 1.

[0028] The fixing frame 6 includes a hollow rectangular frame body 61 and fixing rods 62. The rectangular frame body 61 is fixed to the inner wall surface of the coal roadway 100 through a plurality of fixing rods 62.

[0029] Polyurethane foaming agent is filled in the gap between the pressure airbag 4 and the inner wall surface of the coal roadway 100.

[0030] A gas sensor 12 is also provided on the extraction pipe 10. The gas sensor 12 is electrically connected to a PLC controller. The gas sensor 12 is used to judge the gas concentration of the extracted gas and judge whether there is a risk of residual coal spontaneous combustion in the goaf.

[0031] The nitrogen generator 7, displacement induction switch 3, electromagnetic check valve 13, first pressure sensor 51, second pressure sensor 52, first solenoid valve 8, and second solenoid valve 11 are all electrically connected to the PLC controller.

[0032] Embodiment 2

[0033] Referring to Figure 1 , an automatic pressure equalization method for a closed coal roadway, which is implemented by using the automatic pressure equalization device for a closed coal roadway in Embodiment 1, specifically including the following steps:

[0034] The PLC controller controls the electromagnetic check valve 13 to open, the first solenoid valve 8 and the second solenoid valve 11 to close, and the displacement induction switch 3 to turn on;

[0035] When the gas pressure P1 in the area of the coal roadway 100 on the front side of the telescopic nitrogen storage device measured by the first pressure sensor 51 is greater than the gas pressure P2 in the space between the airtight wall 300 and the goaf 200 measured by the second pressure sensor 52, the nitrogen in the telescopic nitrogen storage device is injected into the space between the airtight wall 300 and the goaf 200 through the injection pipeline 15 until P1 and P2 are balanced. The slider 2 automatically stops sliding. The electromagnetic check valve 13 ensures that the gas cannot flow back into the telescopic nitrogen storage device. The position of the slider 2 is monitored by the displacement induction switch 3 throughout the process. When the slider 2 slides to an incompressible state and touches the displacement induction switch 3, the electromagnetic check valve 13 is immediately closed, and the nitrogen generator 7 and the first solenoid valve 8 are turned on. Nitrogen is filled into the housing 1 through the inlet pipeline 14 to replenish nitrogen for the telescopic nitrogen storage device until it is full. After the slider 2 returns to its original position and touches the displacement induction switch 3, the PLC controller closes the nitrogen generator 7 and the first solenoid valve 8 and opens the electromagnetic check valve 13;

[0036] When the gas pressure P1 in the area of the coal roadway 100 on the front side of the telescopic nitrogen storage device measured by the first pressure sensor 51 is less than the gas pressure P2 in the space between the airtight wall 300 and the goaf 200 measured by the second pressure sensor 52, since the electromagnetic check valve 13 is opened, it is ensured that the gas in the space between the airtight wall 300 and the goaf 200 cannot flow back into the telescopic nitrogen storage device. At this time, the PLC controller opens the second solenoid valve 11 on the extraction pipe 10 to suck the gas in the space between the airtight wall 300 and the goaf 200 into the extraction pipe 10. The position of the slider 2 is monitored by the displacement induction switch 3 throughout the process. When it is found that the slider 2 slides, the second solenoid valve 11 on the extraction pipe 10 is immediately closed.

[0037] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic pressure equalization device for a sealed coal roadway, which is installed in the coal roadway. There is a sealed wall in the coal roadway, and the end of the coal roadway is a goaf. There is a space between the sealed wall and the goaf. Characterized in that, The automatic pressure equalization device for the sealed coal roadway includes a telescopic nitrogen storage device, a pressure airbag, a first pressure sensor, a second pressure sensor, a fixing frame, a nitrogen generator, a U-shaped drainage trough, a drainage pipe, a first solenoid valve, a second solenoid valve, an electromagnetic check valve, an air inlet pipeline, and an injection pipeline; The telescopic nitrogen storage device is fixed in the coal roadway through the fixing frame and is located on the front side of the sealed wall. The telescopic nitrogen storage device includes a housing, a slider, and a displacement induction switch. There is a slider that can slide axially along the inside of the housing in the housing. A displacement induction switch is provided on the inner wall at the end of the housing. The displacement induction switch is used to monitor the moving distance of the slider. The housing is axially placed in the fixing frame, and the end of the fixing frame is fixed on the inner wall surface of the coal roadway. A pressure airbag is provided in the gap between the outside of the fixing frame and the inner wall surface of the coal roadway. An injection pipeline is connected to the air outlet of the housing. The injection pipeline penetrates through the sealed wall and extends into the space between the sealed wall and the goaf, and an electromagnetic check valve is provided on the injection pipeline; A channel is provided axially in the housing, and an air inlet pipeline is provided in the channel. The air inlet end of the air inlet pipeline is connected to the nitrogen generator, and the air outlet end of the air inlet pipeline is connected to the air inlet of the housing. A first solenoid valve is provided on the air inlet pipeline; A first pressure sensor is provided in the coal roadway area on the front side of the telescopic nitrogen storage device to monitor the gas pressure in the coal roadway area on the front side of the telescopic nitrogen storage device. A second pressure sensor is provided in the space between the sealed wall and the goaf to monitor the gas pressure in the space between the sealed wall and the goaf; A U-shaped drainage trough is provided in the rock stratum below the telescopic nitrogen storage device. The drainage pipe sequentially passes through the U-shaped drainage trough and the sealed wall from the coal roadway in front of the telescopic nitrogen storage device and then penetrates into the space between the sealed wall and the goaf, and a second solenoid valve is installed on the drainage pipe.

2. An automatic pressure equalization device for a sealed coal roadway according to claim 1, Characterized in that, The cross-section of the housing is a rectangular structure, and the front end is an open structure. The slider is a rectangular block and is made of rubber material. Lubricating oil is applied between the slider and the inner wall of the housing.

3. An automatic pressure equalization device for a sealed coal roadway according to claim 1, Characterized in that, The fixing frame includes a hollow rectangular frame body and fixing rods. The rectangular frame body is fixed to the inner wall surface of the coal roadway through a plurality of fixing rods.

4. An automatic pressure equalization device for a sealed coal roadway according to claim 1, Characterized in that, The gap between the pressure airbag and the inner wall surface of the coal roadway is filled with polyurethane foam.

5. An automatic pressure equalization device for a sealed coal roadway according to claim 1, Characterized in that, A gas sensor is also provided on the drainage pipe, and the gas sensor is electrically connected to a PLC controller.

6. An automatic pressure equalization device for a sealed coal roadway according to claim 1, Characterized in that, The nitrogen generator, displacement induction switch, electromagnetic check valve, first pressure sensor, second pressure sensor, first solenoid valve, and second solenoid valve are all electrically connected to the PLC controller.

7. An automatic pressure equalization method for a sealed coal roadway, implemented using the automatic pressure equalization device for a sealed coal roadway according to any one of claims 1-6. Specifically It includes the following steps: The PLC controller controls the electromagnetic check valve to open, the first solenoid valve and the second solenoid valve to close, and the displacement induction switch to turn on; When the gas pressure P1 in the coal roadway area in front of the telescopic nitrogen storage device measured by the first pressure sensor is greater than the gas pressure P2 in the space between the sealed wall and the goaf measured by the second pressure sensor, the nitrogen in the telescopic nitrogen storage device is injected into the space between the sealed wall and the goaf through the injection pipeline until P1 and P2 are balanced. The slider automatically stops sliding, and the electromagnetic check valve ensures that the gas cannot flow back into the telescopic nitrogen storage device. The position of the slider is monitored by the displacement induction switch throughout the process. When the slider slides to an incompressible state and touches the displacement induction switch, the electromagnetic check valve is immediately closed, the nitrogen generator and the first solenoid valve are turned on, and nitrogen is filled into the shell through the intake pipeline to replenish the nitrogen in the telescopic nitrogen storage device until it is full. After the slider returns to its original position and touches the displacement induction switch, the PLC controller closes the nitrogen generator and the first solenoid valve and opens the electromagnetic check valve; When the gas pressure P1 in the coal roadway area in front of the telescopic nitrogen storage device measured by the first pressure sensor is less than the gas pressure P2 in the space between the sealed wall and the goaf measured by the second pressure sensor, since the electromagnetic check valve is opened, it is ensured that the gas in the space between the sealed wall and the goaf cannot flow back into the telescopic nitrogen storage device. At this time, the PLC controller opens the second solenoid valve on the extraction pipe to suck the gas in the space between the sealed wall and the goaf into the extraction pipe, and the position of the slider is monitored by the displacement induction switch throughout the process. When it is found that the slider slides, the second solenoid valve on the extraction pipe is immediately closed.

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