A rapid measurement device and method for gas pressure in high-moisture coal seams

Abstract

This invention provides a rapid measurement device and method for gas pressure in high-moisture coal seams, relating to the field of coal seam gas pressure measurement. The device includes: a pressure measurement and sealing unit, a gas-liquid separation unit, a pressure acquisition unit, a gas compression unit, and a drainage unit. The pressure measurement and sealing unit injects liquid and mud into the target sealing area to seal the target sealing area. The gas compression unit compresses air in the non-target sealing area within the borehole, causing the water-containing gas in the borehole to flow towards the drainage unit. The gas-liquid separation unit separates the water-containing gas in the borehole into water and liquid, with the separated liquid discharged through the drainage unit. The pressure of the separated gas is measured by the pressure acquisition unit to obtain the gas pressure within the borehole. The technical solution of this invention overcomes the problems of insufficient accuracy and reliability in pressure measurement caused by the lack of systematic solutions for gas-liquid separation, active pressure maintenance, and moisture content coupling correction in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of coal seam gas pressure measurement, and specifically to a rapid measurement device and method for gas pressure in high-moisture coal seams. Background Technology

[0002] As shallow resources are depleted and coal mines expand into deeper areas, gas occurrence becomes more complex. Coal seam gas pressure, as a key parameter for assessing the risk of coal seam outbursts, plays a fundamental role in gas prevention and control. Accurate measurement of coal seam gas pressure has significant theoretical and practical value for ensuring the safe operation of mines.

[0003] The gas pressure in high-water-cut coal seams differs significantly from that in dry coal seams due to the strong interference of water, exhibiting different occurrence patterns, measurement difficulties, and engineering impacts. A series of problems hinder effective gas monitoring and analysis in high-water-cut coal seams. Moisture filling fracture spaces reduces the gas desorption rate and impedes its flow path, leading to distorted pressure measurement results and slow system response. Conventional sealing techniques are prone to leakage under these geological conditions, resulting in seal failure. The entry of gas-water mixtures into the sensor can cause measurement errors and equipment malfunctions. Furthermore, pressure measurement methods relying on natural equilibrium have long cycles, failing to meet the real-time and efficiency requirements of engineering practice.

[0004] Existing technologies focus primarily on improving the sealing process, but fail to systematically address issues such as gas-liquid separation, active pressure maintenance, and moisture content coupling correction, resulting in insufficient pressure measurement accuracy and reliability.

[0005] Therefore, there is a need for a drainage pressure measurement device and method that can accurately, quickly and easily measure the gas pressure in water-bearing coal seams. Summary of the Invention

[0006] The main objective of this invention is to provide a rapid measurement device and method for gas pressure in high-moisture coal seams, in order to solve the problems of insufficient accuracy and reliability in pressure measurement caused by the lack of systematic solutions for gas-water separation, active pressure maintenance, and moisture content coupling correction in the prior art.

[0007] To achieve the above objectives, the present invention provides a rapid measurement device for gas pressure in high water-content coal seams, comprising: a pressure measurement and sealing unit, a gas-liquid separation unit, a pressure acquisition unit, a gas compression unit, and a drainage unit; the pressure measurement and sealing unit is used to inject liquid and mud into the target sealing area to seal the target sealing area; the gas compression unit compresses the air in the non-target sealing area of ​​the borehole, causing the water-containing gas in the borehole to flow to the drainage unit; the gas-liquid separation unit separates the water-containing gas in the borehole into gas and water, the separated liquid is discharged through the drainage unit, and the separated gas pressure in the borehole is measured by the pressure acquisition unit.

[0008] Furthermore, the pressure-testing and sealing unit includes: an injection pump, a grouting pump, an injection pressure gauge, a first valve, a grouting pipe, an injection tube, an injection pressure gauge, a first sluice bag, a second sluice bag, a return sluice pipe, and a sluice tank. The grouting pump is used to inject water-resistant mud into the target sealing area within the borehole. The sluice tank and the grouting pump are connected via an injection pipe. One end of the injection pipe is connected to the grouting pump, and the other end extends to the grouting layer between the first and second sluice bags within the borehole. The first and second sluice bags are respectively installed on the upper and lower sides of the target sealing area within the borehole. The injection pressure gauge is connected to the grouting pump to monitor the grouting pressure and ensure grout compaction. The injection pump is used to inject water-resistant injection fluid into the first and second sluice bags. The injection tube has three connecting ports, the first connecting port of which is... The injection pipe is connected to the injection pump. The second and third connecting ports of the injection pipe are connected to the first and second bladders, respectively. The first valve is installed on the injection pipe to control the injection speed. The injection pressure gauge is connected to the injection pump and is used to monitor the pressure during the injection process to prevent the first and second bladders from over-expanding and being damaged. The return pipe and slurry tank are used to determine whether the grouting process is complete. One end of the return pipe extends to the grouting layer, and the other end is connected to the slurry tank. The end face of the return pipe located in the grouting layer is higher than the end face of the injection pipe. After the first and second bladders are injected with liquid, they expand and fit tightly against the borehole wall to form a preliminary seal. After the grouting layer is injected with mud, a secondary seal is formed. The upper end of the first bladder and the borehole together form a sealed pressure measuring chamber.

[0009] Furthermore, the gas-water separation unit includes: a gas-water separator, a hydrophobic and breathable membrane, a first water level detector, a second water level detector, a fourth valve, a fifth valve, and a funnel-shaped water collection chamber; the hydrophobic and breathable membrane is located within the funnel-shaped water collection chamber and divides the funnel-shaped water collection chamber into a primary chamber located above the hydrophobic and breathable membrane and a secondary chamber located below the hydrophobic and breathable membrane; the gas-water separator is symmetrically arranged on the hydrophobic and breathable membrane, and the gas-water separator includes a multi-stage hydrophobic structure. The gas-water separator also has a gas-water separator inlet. The multi-stage hydrophobic structure allows gas to pass through the primary chamber from the gas-water separator inlet and prevents moisture from entering the primary chamber; the fourth valve and the fifth valve are symmetrically arranged and located within the secondary chamber. On the lower side wall of the secondary chamber, there is a drainage system to remove accumulated water after separation, preventing water buildup from affecting the separation effect. The opening and closing of the fourth and fifth valves are controlled by the detection results of the first and second water level detectors. The first water level detector is located above the fifth valve, and the second water level detector is located below the fifth valve. When the water level is higher than the first water level detector, the fourth and fifth valves are closed; when it is lower than the second water level detector, the fourth and fifth valves are opened. When the water level is between the two detectors, the valves remain in their current state. The first and second water level detectors are fixed on the side wall of the secondary chamber to monitor the water level in the orifice in real time, providing a basis for drainage operations and pressure correction.

[0010] Furthermore, the pressure acquisition unit includes: a pressure sensor, a sixth valve, a data cable, a data acquisition card, and a computer. The pressure sensor is located in the primary chamber and is used to acquire the gas pressure signal in the primary chamber. The sixth valve is installed on the data cable pipeline to block gas from entering the data cable pipeline. The data cable pipeline is installed along the wall of the water collection pipe, and the data cable is located inside the data cable pipeline. One end of the data cable is connected to the pressure sensor, and the other end is connected to the data acquisition card. The data acquisition card is electrically connected to the computer and is used to transmit the acquired pressure signal to the computer to realize real-time recording and analysis of pressure data.

[0011] Furthermore, the drainage unit includes: a water collection pipe, a drain pipe, a water storage tank, a water tank pressure gauge, a third valve, and a drain outlet; one end of the water collection pipe is connected to the water storage tank via a tee pipe and a drain pipe, and the other end of the water collection pipe is connected to a funnel-shaped water collection cavity; the water tank pressure gauge is installed on the water storage tank and is used to monitor the pressure inside the water storage tank; the third valve is installed on the drain outlet and is used to control the opening and closing of the drainage channel; the drain outlet is located at the bottom of the water storage tank and is used to drain the accumulated water inside the water storage tank.

[0012] Furthermore, the air compression unit includes: an air compressor, an air compressor pressure gauge, a second valve, an air injection pipe, an air bladder, and a side-perforated air pipe. One end of the air injection pipe is connected to the air compressor, and the other end is connected to the side-perforated air pipe. The air compressor is used to inflate the air bladder. The second valve is located on the air injection pipe and is used to control the opening and closing of the gas delivery channel. The air compressor pressure gauge is located on the air injection pipe near the air compressor outlet and is used to monitor the gas pressure inside the air compressor. Small inflation holes are evenly distributed on the side-perforated air pipe. The side-perforated air pipe is arranged in a ring along the outer edge of the funnel-shaped water collection cavity, away from the water collection pipe. The air bladder is fitted onto the side-perforated air pipe. After the gas is delivered from the air compressor, it passes through the air injection pipe and the inflation holes and is evenly injected into the air bladder. The air bladder squeezes the air above the borehole to quickly drain the water.

[0013] Furthermore, the air compressor inflates the airbag with gas.

[0014] Furthermore, the air compressor uses a 0.6MPa air pressure. The air compressor output is connected in sequence to the air pressure gauge and the second valve. The pressure threshold is set, and when the pressure inside the airbag is lower than the balance pressure by 0.1–0.2MPa, air is automatically replenished to maintain the positive pressure stability of the airbag.

[0015] This invention also provides a method for rapid measurement of gas pressure in high water-content coal seams, specifically including the following steps: S1. Accurately connect the pressure sensor to the data cable, place the first water level detector and the second water level detector at the set water level height, and fix them in the funnel-shaped water collection cavity; check the integrity of each component of the device, check the airtightness of all valves, and ensure that there is no air or water leakage; accurately connect each unit, ensure that all pipelines are unobstructed, and place the device in the target sealing area of ​​the borehole. S2. After placing the device in the designated position inside the borehole, open the first valve and start the injection pump to inject liquid into the first and second bags. The bags gradually expand and fully adhere to the borehole wall. Then, close the first valve. Start the grouting pump and inject mud into the grouting layer area through the grouting pipe. During the grouting process, observe the grouting pressure gauge and the return grout pipe. Once the grout tank shows a return grout, it indicates that the grouting layer is full of mud and the grouting is complete. Turn off the grouting pump and the borehole sealing is finished. At this time, the first and second bags cooperate with the grouting layer to form a closed pressure measuring chamber inside the borehole.

[0016] Furthermore, it also includes the following steps: S3, after grouting and sealing, the water accumulation data collected by the first and second water level detectors is used to determine the water accumulation situation in the borehole; the second, third, fourth, and fifth valves are opened, the air compressor unit is started, and the air compressor delivers gas to the air injection pipe. The gas is injected into the air bladder through the side-opening air pipe, causing the air bladder to inflate and compress the air in the upper part of the borehole, promoting the discharge of water and some gas from the fourth and fifth valves, flowing into the water collection pipe, and then being transported to the water storage tank through the drain pipe; when the first water level detector shows that there is no water in the borehole and the second water level detector detects a drop in water level, the third valve is closed. At this point, the water in the water collection pipe and storage tank forms a liquid seal to prevent gas leakage from the drain pipe. The gas in the coal seam passes through the gas-liquid separator, and after deep gas-liquid separation through the hydrophobic and permeable membrane, it enters the primary chamber. The sixth valve remains closed, and the pressure sensor begins to collect the gas pressure signal. The pressure signal is transmitted to the data acquisition card via the data cable, and then from the data acquisition card to the computer. The staff observes the pressure value changes on the computer. When the pressure sensor value stabilizes at a certain value, that value is the gas pressure measured in the borehole. The computer records the data changes in real time for subsequent gas content analysis. S4. After the gas pressure measurement is completed, open the third, fourth and fifth valves to release the remaining gas in the device and ensure that the pressure inside the device is balanced with the outside pressure; gradually dismantle each component of the device, and after dismantling, seal the entire borehole.

[0017] The present invention has the following beneficial effects: 1. Solving the problem of water accumulation interference: The compressed air unit, including a blower, a side-opening air pipe, and an air bag, actively injects nitrogen to compress the air above the borehole. This, combined with the water collection pipe and water tank of the drainage unit, quickly drains the water accumulated in the borehole. At the same time, the first and second water level detectors monitor the water accumulation status in real time to ensure thorough drainage and effectively avoid falsely high gas pressure readings caused by water column pressure, laying the foundation for accurate pressure measurement.

[0018] 2. Thorough gas-water separation and high measurement accuracy: The gas-water separation unit adopts a multi-stage hydrophobic structure that combines a gas-water separator with a hydrophobic and breathable membrane to achieve thorough separation of gas and water, avoiding interference from moisture with the pressure sensor's signal acquisition. Combined with a high-precision pressure sensor, this significantly improves the accuracy of gas pressure measurement.

[0019] 3. Short pressure measurement cycle and high efficiency: By actively compressing air and draining water, the gas seepage time is shortened. Combined with the real-time data acquisition and recording of the pressure acquisition unit, the gas does not need to fill the pressure measurement tube, which greatly shortens the traditional pressure measurement cycle and realizes rapid measurement of gas pressure. This effectively improves the efficiency of coal mine gas measurement and reduces the impact on mining progress.

[0020] 4. High adaptability and safety: The device's structural design is tailored to the geological characteristics of coal seams with high water content and low permeability. The coordinated operation of each unit not only enables rapid and accurate pressure measurement but also prevents gas leakage through liquid seals and other structures, thus improving the safety of coal mine gas control and having broad application prospects. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 A schematic diagram of the structure of a rapid measurement device for gas pressure in high water-content coal seams according to the present invention is shown.

[0022] Figure 2 A schematic diagram of a portion of the device after the airbag of the present invention has been inflated is shown.

[0023] Figure 3 A partial structural diagram of the gas-water separation unit of the present invention is shown.

[0024] Figure 4 A cross-sectional view of a portion of the structure of the air compressor unit of the present invention is shown.

[0025] In the above description of the attached figures: 1. Air compressor; 2. Liquid injection pump; 3. Grouting pump; 4. Data acquisition card; 5. Computer; 6. Water storage tank; 7. Liquid injection pressure gauge; 8. First valve; 9. Air compressor pressure gauge; 10. Second valve; 11. Third valve; 12. Drain outlet; 13. Water tank pressure gauge; 14. T-connector; 15. Data cable; 16. Drain pipe; 17. Air injection pipe; 18. Grouting pipe; 19. Grouting pressure gauge; 20. Drill hole; 21. Fourth valve; 22. Fifth valve; 23. Sixth valve; 24. Air-water separator; 241. Gas 25. Water separator air inlet; 26. First water level detector; 27. Hydrophobic and breathable membrane; 28. Pressure sensor; 29. ​​First bag; 20. Second bag; 31. Water collection pipe; 32. Air bag; 33. Side-opening air pipe; 34. Inflation hole; 35. Second water level detector; 36. Slurry return pipe; 37. Slurry tank; 38. Liquid injection pipe; 39. Funnel-shaped water collection cavity; 30. Data cable pipe; 100. Sealed pressure measuring chamber; 200. Primary chamber; 300. Secondary chamber; 400. Rock stratum; 500. Coal seam. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0027] A rapid measurement device for gas pressure in high-moisture coal seams includes: a pressure measurement and sealing unit, a gas-liquid separation unit, a pressure acquisition unit, a gas compression unit, and a drainage unit. The pressure measurement and sealing unit injects liquid and mud into the target sealing area to seal the target sealing area. The gas compression unit compresses the air in the non-target sealing area of ​​the borehole, causing the water-containing gas in the borehole to flow towards the drainage unit. The gas-liquid separation unit separates the water-containing gas in the borehole into gas and water, and the separated liquid is discharged through the drainage unit. The pressure of the separated gas is measured by the pressure acquisition unit to obtain the gas pressure in the borehole.

[0028] Specifically, such as Figure 1 and Figure 2As shown, the pressure sealing unit includes: an injection pump 2, a grouting pump 3, an injection pressure gauge 7, a first valve 8, a grouting pipe 18, an injection pipe 36, a grouting pressure gauge 19, a first bladder 28, a second bladder 29, a return grout pipe 34, and a grout tank 35. The grouting pump 3 is used to inject water-resistant mud into the target sealing area inside the borehole. The grout tank 35 and the grouting pump 3 are connected through the grouting pipe 18. One end of the grouting pipe 18 is connected to the grouting pump 3, and the other end extends into the first valve 8 inside the borehole 20. The grouting layer between the first grout bag 28 and the second grout bag 29 is provided. The first grout bag 28 and the second grout bag 29 are respectively installed on the upper and lower sides of the target sealing area inside the borehole 20. The grouting pressure gauge 19 is connected to the grouting pump 3 to monitor the grouting pressure and ensure that the grouting is compact. The injection pump 2 is used to inject water-resistant injection liquid into the first grout bag 28 and the second grout bag 29. The injection pipe 36 has three connecting ports. The first connecting port of the injection pipe 36 is connected to the injection pump 2, and the second connecting port of the injection pipe is connected to the injection pump 2. The third connecting port is connected to the first bladder 28 and the second bladder 29 respectively. The first valve 8 is set on the injection pipe 36 to control the injection speed. The injection pressure gauge 7 is connected to the injection pump 2. The injection pressure gauge 7 is used to monitor the pressure during the injection process to prevent the first bladder 28 and the second bladder 29 from being damaged due to excessive expansion. The return pipe 34 and the slurry tank 35 are used to determine whether the grouting process is completed. One end of the return pipe 34 extends to the grouting layer, and the other end is connected to the slurry tank 35. The end face of the return pipe 34 located in the grouting layer is higher than the end face of the injection pipe 18. That is, the end face of the return pipe 34 located in the borehole is close to the first bladder 28, and the end face of the injection pipe 18 located in the borehole is close to the second bladder 29. After the first bladder 28 and the second bladder 29 are injected with liquid, they expand and fit tightly against the borehole wall of the borehole 20 to form a preliminary seal. After the grouting layer is injected with mud, a secondary seal is formed. The upper end of the first bladder 28 and the borehole together form a closed pressure measuring chamber 100.

[0029] like Figure 1 As shown, the device provided by the present invention is located in a cross-layer borehole. The borehole passes through the rock layer 400 and the target coal seam 500 in sequence, and ends in the rock layer 400 1m away from the bottom of the coal seam.

[0030] Specifically, such as Figure 1 and Figure 3As shown, the gas-water separation unit includes: a gas-water separator 24, a hydrophobic and breathable membrane 26, a first water level detector 25, a second water level detector 33, a fourth valve 21, a fifth valve 22, and a funnel-shaped water collection chamber 37. The hydrophobic and breathable membrane 26 is located inside the funnel-shaped water collection chamber 37 and divides the funnel-shaped water collection chamber 37 into a primary chamber 200 located above the hydrophobic and breathable membrane 26 and a secondary chamber 300 located below the hydrophobic and breathable membrane 26. The gas-water separator 24 is symmetrically arranged on the hydrophobic and breathable membrane 26. The gas-water separator 24 includes a multi-stage hydrophobic structure and also has a gas-water separator inlet 241. The multi-stage hydrophobic structure allows gas to pass through the primary chamber 200 from the gas-water separator inlet 241 and prevents moisture from entering the primary chamber 200. The fourth valve 21 and the fifth valve 22 are symmetrically arranged. Located on the lower side wall of the secondary chamber 300, the valves are used to drain the water after separation and prevent water accumulation from affecting the separation effect. The opening and closing of the fourth valve 21 and the fifth valve 22 are controlled by the detection results of the first water level detector 25 and the second water level detector 33. The first water level detector is located 0.5m above the fifth valve, and the second water level detector is located 0.5m below the fifth valve. When the water level is higher than the first water level detector 25, the fourth valve 21 and the fifth valve 22 are closed; when the water level is lower than the second water level detector 33, the fourth valve 21 and the fifth valve 22 are opened. When the water level is between the two detectors, the valves remain in their current state. The first water level detector 25 and the second water level detector 33 are fixed on the side wall of the secondary chamber 300 to monitor the water level in the orifice in real time, providing a basis for drainage operation and pressure correction.

[0031] Specifically, the pressure acquisition unit includes: a pressure sensor 27, a sixth valve 23, a data cable 15, a data acquisition card 4, and a computer 5. The pressure sensor 27 is located in the primary chamber and is used to acquire the gas pressure signal in the primary chamber. The sixth valve 23 is installed on the data cable conduit 38 to block gas from entering the data cable conduit 38 where the data cable 15 is located. The data cable conduit is installed along the wall of the water collection pipe 30. The data cable 15 is located inside the data cable conduit 38. One end of the data cable 15 is connected to the pressure sensor 27, and the other end is connected to the data acquisition card 4. The data acquisition card 4 is electrically connected to the computer 5 and is used to transmit the acquired pressure signal to the computer 5 to realize real-time recording and analysis of pressure data.

[0032] Specifically, the drainage unit includes: a water collection pipe 30, a drain pipe 16, a water storage tank 6, a water tank pressure gauge 13, a third valve 11, and a drain outlet 12; one end of the water collection pipe 30 is connected to the water storage tank 6 through a tee pipe 14 and the drain pipe 16, and the other end of the water collection pipe 30 is connected to a funnel-shaped water collection cavity 37; the water tank pressure gauge 13 is installed on the water storage tank 6 and is used to monitor the pressure inside the water storage tank 6; the third valve 11 is installed on the drain outlet 12 and is used to control the opening and closing of the drainage channel; the drain outlet 12 is located at the bottom of the water storage tank 6 and is used to drain the accumulated water inside the water storage tank 6.

[0033] Specifically, such as Figure 1 and Figure 4 As shown, the air compressor unit includes: an air compressor 1, an air compressor pressure gauge 9, a second valve 10, an air injection pipe 17, an air bladder 31, and a side-opening air pipe 32; one end of the air injection pipe 17 is connected to the air compressor 1, and the other end is connected to the side-opening air pipe 32; the air compressor 1 is used to inflate the air bladder 31; the second valve 10 is located on the air injection pipe 17 and is used to control the opening and closing of the gas delivery channel; the air compressor pressure gauge 9 is located on the air injection pipe 17 near the outlet of the air compressor 1 and is used to monitor the gas pressure inside the air compressor 1; the side opening... Inflation holes 321 are evenly distributed on the tracheal tube 32. The tracheal tube 32 with side openings is arranged in a ring along the outer edge of the end of the funnel-shaped water collection cavity 37 away from the water collection pipe 30. The airbag 31 is fitted on the tracheal tube 32 with side openings. After the gas is sent out from the blower 1, it passes through the air injection pipe 17 and the inflation holes 321 and is evenly injected into the airbag 31. The airbag 31 squeezes the air in the upper part of the drill hole 20 to drain the air quickly. The airbag 31, the first bag 28, and the second bag 29 cooperate with each other to further improve the airtightness.

[0034] Specifically, the air compressor inflates the airbag with gas.

[0035] Specifically, the air compressor 1 uses a wind pressure of 0.6MPa. The output end of the air compressor 1 is connected in sequence to the fan pressure gauge 9 and the second valve 10. The pressure threshold is set. When the pressure inside the airbag 31 is lower than the balance pressure by 0.1–0.2MPa, air is automatically replenished to maintain the positive pressure stability of the airbag 31.

[0036] Specifically, the data acquisition card 4 is electrically connected to the pressure sensor 27, the first water level detector 25, and the second water level detector 33 to synchronously acquire gas pressure data and water level data. The computer 5 records the data change trend in real time, which is convenient for staff to analyze. Example 2

[0037] A rapid method for measuring gas pressure in high-moisture coal seams includes the following steps: S1, Device Inspection and Connection: Accurately connect the pressure sensor 27 to the data cable 15; place the first water level detector 25 and the second water level detector 33 at the set water level height and fix them in the funnel-shaped water collection cavity 37; check the integrity of each component of the device; check the airtightness of all valves (first valve 8, second valve 10, third valve 11, fourth valve 21, fifth valve 22, and sixth valve 23) to ensure there is no air or water leakage; accurately connect each unit through the tee pipe 14, drain pipe 16, air injection pipe 17, etc., to ensure all pipes are unobstructed; place the device in the target sealing area of ​​the borehole 20. S2, sealing operation to form a closed pressure measuring chamber: After placing the device in the designated position inside the borehole 20, open the first valve 8, start the injection pump 2, and inject liquid into the first bag 28 and the second bag 29. The bags gradually expand and fully adhere to the borehole wall of the borehole 20. Then close the first valve 8. Start the grouting pump 3 and inject mud into the grouting layer area through the grouting pipe 18. During the grouting process, always observe the grouting pressure gauge 19 and the return grout pipe 34. Once the grout tank 35 shows a return grout, it indicates that the grouting layer has been filled with mud and the grouting is complete. Turn off the grouting pump 3 and the sealing is finished. At this time, the first bag 28 and the second bag 29 cooperate with the grouting layer to form a closed pressure measuring chamber 100 inside the borehole.

[0038] Specifically, it also includes the following steps: S3, Active Drainage and Pressure Measurement: After grouting and sealing, the water accumulation data collected by the first water level detector 25 and the second water level detector 33 are used to determine the water accumulation situation in the borehole; the second valve 10, the third valve 11, the fourth valve 21, and the fifth valve 22 are opened, and the air compression unit is started. The air compressor 1 delivers gas to the air injection pipe 17. The gas is injected into the air bag 31 through the side-opening air pipe 32, causing the air bag 31 to inflate and squeeze the air in the upper part of the borehole 20, promoting the discharge of water and some gas in the borehole from the fourth valve 21 and the fifth valve 22, flowing into the water collection pipe 30, and then being transported to the water storage tank 6 through the drain pipe 16; when the first water level detector 25 shows that there is no water in the borehole and the second water level detector 33 detects the water level... When the pressure is reduced, the third valve 11 is closed. At this time, the water in the water collection pipe 30 and the water storage tank 6 forms a liquid seal to prevent gas leakage from the drain pipe. The gas in the coal seam passes through the gas-water separator 24 and the hydrophobic and breathable membrane 26 to achieve deep gas-water separation before entering the primary chamber 200. The sixth valve 23 remains closed, and the pressure sensor 27 begins to collect the gas pressure signal. The pressure signal is transmitted to the data acquisition card 4 via the data cable 15, and then transmitted to the computer 5 via the data acquisition card 4. The staff observes the pressure value changes on the computer 5. When the pressure sensor 27 value stabilizes at a certain value, that value is the gas pressure measured in the borehole 20. The computer 5 records the data changes in real time for subsequent gas content analysis. S4, Device dismantling and borehole sealing: After the gas pressure measurement is completed, open the third valve 11, the fourth valve 21 and the fifth valve 22 to release the remaining gas in the device and ensure that the pressure inside the device is balanced with the outside. Gradually dismantle each component of the device. After dismantling, seal the entire borehole 20 to prevent gas leakage and ensure the safety of coal mining.

[0039] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A rapid measuring device for gas pressure in high-moisture coal seams, characterized in that, include: The system comprises a pressure sealing unit, a gas-liquid separation unit, a pressure acquisition unit, a compressed air unit, and a drainage unit. The pressure sealing unit injects liquid and mud into the target sealing area to seal the borehole. The compressed air unit compresses the air in the non-target sealing area of ​​the borehole, causing the water-containing gas in the borehole to flow towards the drainage unit. The gas-liquid separation unit separates the water-containing gas in the borehole into water and liquid. The separated liquid is discharged through the drainage unit, and the pressure of the separated gas in the borehole is measured by the pressure acquisition unit. The gas-liquid separation unit includes: a gas-liquid separator, a hydrophobic and breathable membrane, a first water level detector, a second water level detector, a fourth valve, a fifth valve, and a funnel-shaped water collection chamber; A hydrophobic and breathable membrane is located within a funnel-shaped water collection cavity, dividing the cavity into a primary chamber above the membrane and a secondary chamber below it. A gas-liquid separator is symmetrically positioned on the membrane and includes a multi-stage hydrophobic structure. The separator also features an air inlet. This multi-stage hydrophobic structure allows gas to pass through the primary chamber from the air inlet while preventing moisture from entering. A fourth and fifth valve are symmetrically positioned on the lower sidewall of the secondary chamber to drain the separated water, preventing water accumulation from affecting the separation process. In terms of effectiveness, the opening and closing of the fourth and fifth valves are controlled by the detection results of the first and second water level detectors. The first water level detector is located above the fifth valve, and the second water level detector is located below the fifth valve. When the water level is higher than the first water level detector, the fourth and fifth valves are closed; when the water level is lower than the second water level detector, the fourth and fifth valves are opened. When the water level is between the two detectors, the valves remain in their current state. The first and second water level detectors are fixed on the side wall of the secondary chamber and are used to monitor the water level in the orifice in real time, providing a basis for drainage operations and pressure correction.

2. The rapid measurement device for gas pressure in high-moisture coal seams according to claim 1, characterized in that, The pressure-testing and sealing unit includes: an injection pump, a grouting pump, an injection pressure gauge, a first valve, a grouting pipe, an injection tube, an injection pressure gauge, a first sluice bag, a second sluice bag, a return sluice pipe, and a sluice tank. The injection pump injects water-resistant mud into the target sealing area within the borehole. The sluice tank and the injection pump are connected via an injection pipe. One end of the injection pipe is connected to the injection pump, and the other end extends to the grouting layer between the first and second sluice bags within the borehole. The first and second sluice bags are respectively installed on the upper and lower sides of the target sealing area within the borehole. The injection pressure gauge is connected to the injection pump to monitor the grouting pressure and ensure grout compaction. The injection pump injects water-resistant injection fluid into the first and second sluice bags. The injection tube has three connecting ports. The first connecting port of the injection tube is connected to... The injection pump is connected, and the second and third connecting ports of the injection pipe are connected to the first and second bladders, respectively. A first valve is installed on the injection pipe to control the injection speed. The injection pressure gauge is connected to the injection pump and is used to monitor the pressure during the injection process to prevent the first and second bladders from over-expanding and being damaged. The return slurry pipe and slurry tank are used to determine whether the grouting process is complete. One end of the return slurry pipe extends to the grouting layer, and the other end is connected to the slurry tank. The end face of the return slurry pipe located in the grouting layer is higher than the end face of the injection pipe. After the first and second bladders are injected with liquid, they expand and fit tightly against the borehole wall to form a preliminary seal. After the grouting layer is injected with mud, a secondary seal is formed. The upper end of the first bladder and the borehole together form a sealed pressure measuring chamber.

3. The rapid measurement device for gas pressure in high-moisture coal seams according to claim 1, characterized in that, The pressure acquisition unit includes: a pressure sensor, a sixth valve, a data cable, a data acquisition card, and a computer. The pressure sensor is located in the primary chamber and is used to acquire the gas pressure signal in the primary chamber. The sixth valve is installed on the data cable pipeline to prevent gas from entering the data cable pipeline. The data cable pipeline is installed along the wall of the water collection pipe, and the data cable is located inside the data cable pipeline. One end of the data cable is connected to the pressure sensor, and the other end is connected to the data acquisition card. The data acquisition card is electrically connected to the computer and is used to transmit the acquired pressure signal to the computer to realize real-time recording and analysis of pressure data.

4. The rapid measurement device for gas pressure in high-moisture coal seams according to claim 1, characterized in that, The drainage unit includes: a water collection pipe, a drain pipe, a water storage tank, a water tank pressure gauge, a third valve, and a drain outlet; one end of the water collection pipe is connected to the water storage tank via a tee pipe and a drain pipe, and the other end of the water collection pipe is connected to a funnel-shaped water collection cavity; the water tank pressure gauge is installed on the water storage tank and is used to monitor the pressure inside the water storage tank; the third valve is installed on the drain outlet and is used to control the opening and closing of the drainage channel; the drain outlet is located at the bottom of the water storage tank and is used to drain the accumulated water in the water storage tank.

5. The rapid measurement device for gas pressure in high-moisture coal seams according to claim 1, characterized in that, The air compression unit includes: an air compressor, an air compressor pressure gauge, a second valve, an air injection pipe, an air bladder, and a side-perforated air pipe. One end of the air injection pipe is connected to the air compressor, and the other end is connected to the side-perforated air pipe. The air compressor is used to inflate the air bladder. The second valve is located on the air injection pipe and is used to control the opening and closing of the gas delivery channel. The air compressor pressure gauge is located on the air injection pipe near the air compressor outlet and is used to monitor the gas pressure inside the air compressor. Small inflation holes are evenly distributed on the side-perforated air pipe. The side-perforated air pipe is arranged in a ring along the outer edge of the funnel-shaped water collection cavity, away from the water collection pipe. The air bladder is fitted onto the side-perforated air pipe. After the gas is delivered from the air compressor, it passes through the air injection pipe and the inflation holes and is evenly injected into the air bladder. The air bladder squeezes the air above the borehole to quickly drain the air. The air compressor inflates the air bladder with gas.

6. The rapid measurement device for gas pressure in high-moisture coal seams according to claim 5, characterized in that, The air compressor uses a 0.6MPa air pressure. The air compressor output is connected in sequence to the air pressure gauge and the second valve. The pressure threshold is set. When the pressure inside the airbag is lower than the balance pressure by 0.1–0.2MPa, the air is automatically replenished to maintain the positive pressure stability of the airbag.

7. A method for rapid measurement of gas pressure in high-moisture coal seams, utilizing the apparatus described in any one of claims 1-6, characterized in that, Specifically, the steps include the following: S1. Accurately connect the pressure sensor to the data cable, place the first water level detector and the second water level detector at the set water level height, and fix them in the funnel-shaped water collection cavity; check the integrity of each component of the device, check the airtightness of all valves, and ensure that there is no air or water leakage; accurately connect each unit, ensure that all pipelines are unobstructed, and place the device in the target sealing area of ​​the borehole. S2. After placing the device in the designated position inside the borehole, open the first valve and start the injection pump to inject liquid into the first and second bags. The bags gradually expand and fully adhere to the borehole wall. Then, close the first valve. Start the grouting pump and inject mud into the grouting layer area through the grouting pipe. During the grouting process, observe the grouting pressure gauge and the return grout pipe. Once the grout tank shows a return grout, it indicates that the grouting layer is full of mud and the grouting is complete. Turn off the grouting pump and the borehole sealing is finished. At this time, the first and second bags cooperate with the grouting layer to form a closed pressure measuring chamber inside the borehole.

8. The method for rapid measurement of gas pressure in high water-bearing coal seams according to claim 7, characterized in that, It also includes the following steps: S3, after grouting and sealing, the water accumulation data collected by the first and second water level detectors is used to determine the water accumulation situation in the borehole; the second, third, fourth, and fifth valves are opened, the air compressor unit is started, and the air compressor delivers gas to the air injection pipe. The gas is injected into the air bladder through the side-opening air pipe, causing the air bladder to inflate and compress the air in the upper part of the borehole, promoting the discharge of water and some gas from the fourth and fifth valves, flowing into the water collection pipe, and then being transported to the water storage tank through the drain pipe; when the first water level detector shows that there is no water in the borehole and the second water level detector detects a drop in water level, the third valve is closed. At this point, the water in the water collection pipe and storage tank forms a liquid seal to prevent gas leakage from the drain pipe. The gas in the coal seam passes through the gas-liquid separator, and after deep gas-liquid separation through the hydrophobic and permeable membrane, it enters the primary chamber. The sixth valve remains closed, and the pressure sensor begins to collect the gas pressure signal. The pressure signal is transmitted to the data acquisition card via the data cable, and then from the data acquisition card to the computer. The staff observes the pressure value changes on the computer. When the pressure sensor value stabilizes at a certain value, that value is the gas pressure measured in the borehole. The computer records the data changes in real time for subsequent gas content analysis. S4. After the gas pressure measurement is completed, open the third, fourth and fifth valves to release the remaining gas in the device and ensure that the pressure inside the device is balanced with the outside pressure; gradually dismantle each component of the device, and after dismantling, seal the entire borehole.

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