Coal bed gas pressure measuring device and measuring method thereof

Abstract

The present application relates to a coal mine sealing hole pressure measuring equipment, and in particular to a coal seam gas pressure measuring device and its measuring method; it includes a connected sieve hole pipe and a pressure measuring tube; the top of the pressure measuring tube is connected with a three-way pipe, and the other two branches of the three-way pipe are also connected with valves and pressure gauges respectively; a rubber airbag is fixedly installed outside the pressure measuring tube, and a one-way valve with a flow direction from inside to outside and connected to the rubber airbag is installed on the wall of the pressure measuring tube; an airflow channel is formed at the part where the pressure measuring tube leads to the sieve hole pipe. Due to the implementation of the above technical scheme, the present application injects airflow into the pressure measuring tube through a valve connected to an air pump, and the airflow control valve closes the airflow channel, and then the airflow enters the rubber airbag through the one-way valve to achieve sealing; the air pump is removed to remove the air pressure in the pressure measuring tube and then the valve is closed; when the pressure gauge reading is stable for a period of time, the coal seam gas pressure can be obtained; the present application has a simple structure and low production cost, and only the valve needs to be operated at the drilling site, which reduces the labor intensity of the operators.

Description

Technical Field

[0001] The present application relates to a coal mine sealing hole pressure measuring device, and in particular to a coal seam gas pressure measuring device and a measuring method thereof. Background Art

[0002] As the depth of coal mining increases, the gas content and pressure of coal seams increase, and the risk of gas disasters increases. Gas disaster prevention and control is the top priority in ensuring safe coal mining. The coal seam gas pressure value is one of the important indicators for identifying the gas grade of the mine, evaluating the coal and gas outburst hazard of the coal seam, and formulating the gas extraction plan. Measuring coal seam gas pressure is an important part of gas disaster prevention and control work. Whether the coal seam gas pressure value is accurately measured directly affects the safe production of coal mines.

[0003] The existing coal seam gas pressure sealing methods are mainly divided into grouting and air bags; however, no matter which one is used, the structure of the pressure measuring device is relatively complicated, and pressure measurement often requires multiple steps, which is not easy to operate. Summary of the invention

[0004] The purpose of this application is to propose a coal seam gas pressure measuring device and method with simple structure, low manufacturing cost and few construction steps.

[0005] One of the technical solutions of the present application is achieved as follows: a coal seam gas pressure measuring device, which includes a connected sieve hole tube and a pressure measuring tube; the top of the pressure measuring tube is connected to a three-way pipe, and the other two branches of the three-way pipe are also connected to a valve and a pressure gauge respectively; a rubber airbag is fixedly installed on the outside of the pressure measuring tube, and a one-way valve with a flow direction from inside to outside and connected to the inner cavity of the rubber airbag is installed on the wall of the pressure measuring tube; an airflow channel is formed at the part of the pressure measuring tube leading to the sieve hole tube; an airflow control valve is installed at the bottom of the pressure measuring tube, which can close the airflow channel after being impacted by downward high-pressure airflow and can open the airflow channel in a natural state.

[0006] Furthermore, the airflow control valve includes a valve cylinder, a screen plate, a spring and a baffle; the valve cylinder is correspondingly connected between the screen hole tube and the pressure measuring tube; an inner ring platform is provided in the middle of the inner wall of the valve cylinder, and an airflow channel from the pressure measuring tube to the screen hole tube is formed in the middle of the inner ring platform; the screen plate is fixedly installed on the upper part of the inner wall of the valve cylinder, and the lower end surface of the screen plate is fixedly connected to the spring, and the other end of the spring is connected to the baffle which can be pressed against the inner ring platform as the spring moves downward and can block the airflow channel.

[0007] Furthermore, a guide column located inside the spring is fixedly erected on the screen plate.

[0008] Furthermore, the lower end surface of the baffle is in a spherical crown shape, and the lower end surface of the baffle is covered with a sealing layer; the inner ring of the upper end surface of the inner ring platform is provided with an inclined fitting surface with a higher outer side and a lower inner side.

[0009] Furthermore, an upper locking hoop and a lower locking hoop are fixed to the outer wall of the pressure measuring tube; a rubber airbag sleeved outside the pressure measuring tube is installed between the upper locking hoop and the lower locking hoop; a closed annular cavity is formed between the upper locking hoop, the lower locking hoop, the rubber airbag and the pressure measuring tube.

[0010] Furthermore, the top of the pressure measuring tube is connected to a pressure measuring terminal tube via a pipe joint, and the other end of the pressure measuring terminal tube is connected to a three-way tube.

[0011] The second technical solution of the present application is implemented as follows: a method for measuring coal seam gas pressure, characterized in that it includes the following steps: the first step, after the coal seam drilling construction is completed, the sieve hole pipe is downwardly installed in the borehole with the sieve hole pipe and the pressure measuring tube, and the three-way pipe is located outside the borehole; the second step, the air outlet pipe of the air pump is docked and installed at the other end of the valve, the valve is opened, the air pump is started, and the pressure gauge changes are observed at the same time; the third step, the air flow enters the pressure measuring tube, overcomes the spring force to push the baffle downward, and makes the baffle match and fit tightly against the inner ring platform to block the air flow channel; then the gas enters the rubber airbag through the one-way valve, gradually expands the rubber airbag, and the rubber airbag is tightly attached to the inner wall of the borehole to form a seal; the fourth step, when the pressure gauge reading reaches the set value, the air pump is turned off, the air outlet pipe of the air pump is removed from the valve, and the high-pressure gas in the pressure measuring tube is released, and then the valve is closed; the fifth step, the pressure gauge reading changes are recorded, and when the pressure gauge reading is stable for a period of time, the observation is stopped to measure the coal seam gas pressure.

[0012] Due to the implementation of the above technical scheme, the present application injects airflow into the pressure measuring tube by connecting the air pump through the valve. Under the action of the airflow hitting the top, the airflow control valve closes the airflow channel, and then the airflow enters the rubber airbag through the one-way valve to achieve sealing; after removing the air pump and removing the air pressure in the pressure measuring tube, the valve is closed; when the pressure gauge reading is stable for a period of time, the coal seam gas pressure can be obtained; the present application has a simple structure and low production cost, and only the valve needs to be operated at the drilling site, reducing the labor intensity of the operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The specific structure of this application is given by the following drawings and embodiments:

[0014] Figure 1 is a schematic diagram of the structure of Example 1 of the present application;

[0015] Figure 2 yes Figure 1 A schematic cross-sectional structure diagram of ;

[0016] Figure 3 yes Figure 2 Schematic diagram of the local enlarged structure at point I in the middle.

[0017] Legend: 1. Sieve tube, 2. Pressure measuring tube, 3. Tee tube, 4. Valve, 5. Pressure gauge, 6. Rubber airbag, 7. Check valve, 8. Air flow channel, 9. Valve cylinder, 10. Sieve plate, 11. Spring, 12. Baffle, 13. Inner ring platform, 14. Guide column, 15. Sealing layer, 16. Fitting surface, 17. Upper locking hoop, 18. Lower locking hoop, 19. Annular cavity, 20. Pressure measuring end tube, 21. Pipe joint. DETAILED DESCRIPTION

[0018] The present application is not limited by the following embodiments, and the specific implementation method can be determined according to the technical solution of the present application and actual conditions.

[0019] Embodiment 1, as Figures 1 to 3 As shown, the coal seam gas pressure measuring device includes a connected sieve hole pipe 1 and a pressure measuring tube 2; the top of the pressure measuring tube 2 is connected with a three-way pipe 3, and the other two branches of the three-way pipe 3 are respectively connected with a valve 4 and a pressure gauge 5; a rubber air bag 6 is fixedly installed outside the pressure measuring tube 2, and a one-way valve 7 with a flow direction from inside to outside and connected to the inner cavity of the rubber air bag 6 is installed on the wall of the pressure measuring tube 2; an air flow channel 8 is formed at the part where the pressure measuring tube 2 leads to the sieve hole pipe 1; an air flow control valve is installed at the bottom of the pressure measuring tube 2, which can close the air flow channel 8 after being impacted by a downward high-pressure air flow and can open the air flow channel 8 in a natural state.

[0020] During operation, the sieve tube 1 is downwardly installed with the sieve tube 1 and the pressure measuring tube 2 in the borehole, and the pressure measuring tube 2 or the pressure measuring end tube 20 outside the borehole is fixed to the ground through a bracket. The other end of the valve 4 is connected to the air pump, and the high-pressure airflow is injected into the pressure measuring tube 2 through the air pump. Under the impact of the airflow, the airflow control valve closes the airflow channel 8, and then the airflow enters the rubber airbag 6 through the one-way valve 7 to seal the hole; then the air pump is removed to release the high-pressure airflow in the pressure measuring tube 2, and the valve 4 is closed; when the reading of the pressure gauge 5 is stable for a period of time, the coal seam gas pressure can be obtained; the present application has a simple structure, a short production cycle, and a low production cost. The operator only needs to operate the valve 4 at the borehole according to the pressure setting value given by the technician, which reduces the process, reduces the difficulty, and reduces the labor intensity of the operator.

[0021] like Figure 1 , 2 As shown, the airflow control valve includes a valve cylinder 9, a sieve plate 10, a spring 11 and a baffle 12; the valve cylinder 9 is correspondingly connected between the sieve hole tube 1 and the pressure measuring tube 2; an inner ring platform 13 is provided in the middle of the inner wall of the valve cylinder 9, and an airflow channel 8 from the pressure measuring tube 2 to the sieve hole tube 1 is formed in the middle of the inner ring platform 13; the sieve plate 10 is fixedly mounted on the upper part of the inner wall of the valve cylinder 9, and the lower end surface of the sieve plate 10 is fixedly connected to the spring 11, and the other end of the spring 11 is connected to the baffle 12 which can move downward with the spring 11 and press against the inner ring platform 13 and block the airflow channel 8.

[0022] like Figure 2 , 3 As shown, a guide column 14 located inside the spring 11 is fixedly erected on the screen plate 10. In this way, the movement trajectory of the baffle 12 is easier to control under the impact of the airflow, and it is convenient to form an effective seal with the inner ring platform 13.

[0023] like Figure 2 , 3 As shown, the lower end face of the baffle 12 is in the shape of a spherical crown, and the lower end face of the baffle 12 is covered with a sealing layer 15; the inner ring of the upper end face of the inner ring platform 13 is provided with an inclined fitting surface 16 with a high outer side and a low inner side. The airflow impacts the baffle 12 after overcoming the elastic force of the spring 11, and the baffle 12 can only collide with the inner ring platform 13. The movement directions of the airflow and the spring 11 are uncertain, so the contact position of the baffle 12 and the inner ring platform 13 has a relatively large fluctuation. The spherical crown-shaped baffle 12 and the sealing layer 15 can effectively eliminate this defect. No matter how the baffle 12 swings, the fitting surface 16 will eventually form a vertical seal with the baffle 12 and the sealing layer 15 in the shape of a spherical crown.

[0024] like Figure 1 , 2 As shown, an upper locking hoop 17 and a lower locking hoop 18 are fixed to the outer wall of the pressure measuring tube 2; the rubber airbag 6 sleeved outside the pressure measuring tube 2 is installed between the upper locking hoop 17 and the lower locking hoop 18; a closed annular cavity 19 is formed between the upper locking hoop 17, the lower locking hoop 18, the rubber airbag 6 and the pressure measuring tube 2.

[0025] In this way, the distance between the upper locking hoop 17 and the lower locking hoop 18 can be adjusted according to the size of the drill hole and the environment inside the hole, thereby changing the setting diameter of the rubber airbag 6 to expand the scope of application of the present application.

[0026] like Figure 1 , 2 As shown, the top of the pressure measuring tube 2 is connected to a pressure measuring end tube 20 via a pipe joint 21 , and the other end of the pressure measuring end tube 20 is connected to the three-way pipe 3 .

[0027] The sieve tube 1, the pressure measuring tube 2 and the airflow control valve can be mass-produced to reduce costs. The pressure measuring end tube 20 can be produced and installed on site according to the actual coal seam and the drilling depth, and the connection through the pipe joint 21 is quick, time-saving and labor-saving.

[0028] Embodiment 2, a method for measuring coal bed gas pressure, characterized in that it comprises the following steps:

[0029] In the first step, after the coal seam drilling construction is completed, the sieve hole pipe 1 is downwardly installed in the borehole with the sieve hole pipe 1 and the pressure measuring pipe 2, and the tee pipe 3 is located outside the borehole;

[0030] The second step is to connect and install the air outlet pipe of the air pump to the other port of the valve 4, open the valve 4, start the air pump, and observe the changes of the pressure gauge 5 at the same time;

[0031] In the third step, the airflow enters the pressure measuring tube 2, overcomes the elastic force of the spring 11, pushes the baffle 12 downward, and makes the baffle 12 fit tightly against the inner ring 13, thereby blocking the airflow channel 8; then the gas enters the rubber airbag 6 through the one-way valve 7, gradually expands the rubber airbag 6, and the rubber airbag 6 is tightly attached to the inner wall of the borehole to form a seal;

[0032] Step 4: When the reading of the pressure gauge 5 reaches the set value, turn off the air pump, remove the air outlet pipe of the air pump from the valve 4, release the high-pressure gas in the pressure measuring tube 2, and then close the valve 4;

[0033] The fifth step is to record the changes in the reading of pressure gauge 5. When the reading of pressure gauge 5 is stable for a period of time, stop observing and measure the coal seam gas pressure.

[0034] The above technical features constitute the embodiments of the present application, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the needs of different situations.

Claims

1. A coal seam gas pressure measuring device, characterized in that: It includes a connected sieve hole pipe and a pressure measuring tube; the top of the pressure measuring tube is connected with a tee pipe, and the other two branches of the tee pipe are respectively connected with a valve and a pressure gauge; a rubber air bag is fixedly installed outside the pressure measuring tube, and a one-way valve with a flow direction from inside to outside and connected to the inner cavity of the rubber air bag is installed on the wall of the pressure measuring tube; an air flow channel is formed at the part of the pressure measuring tube leading to the sieve hole pipe; an air flow control valve for controlling the on and off of the air flow channel is installed at the bottom of the pressure measuring tube; The airflow control valve comprises a valve cylinder, a screen plate, a spring and a baffle; the valve cylinder is connected between the screen hole tube and the pressure measuring tube; an inner ring platform is provided in the middle of the inner wall of the valve cylinder, and an airflow channel from the pressure measuring tube to the screen hole tube is formed in the middle of the inner ring platform; the screen plate is fixedly installed on the upper part of the inner wall of the valve cylinder, the lower end surface of the screen plate is fixedly connected to the spring, and the other end of the spring is connected to the baffle that can move downward with the spring and press against the inner ring platform and block the airflow channel; A guide column located inside the spring is fixedly erected on the screen plate; The lower end surface of the baffle is in the shape of a spherical crown, and the lower end surface of the baffle is covered with a sealing layer; the inner ring of the upper end surface of the inner ring platform is provided with an inclined fitting surface with a high outer surface and a low inner surface; The outer wall of the pressure measuring tube is respectively fixed with an upper locking hoop and a lower locking hoop; the rubber air bag sleeved outside the pressure measuring tube is installed between the upper locking hoop and the lower locking hoop; the upper locking hoop, the lower locking hoop, the rubber air bag and the pressure measuring tube form a closed annular cavity.

2. The coal bed gas pressure measuring device according to claim 1, characterized in that: The top of the pressure measuring tube is connected with a pressure measuring terminal tube through a pipe joint, and the other end of the pressure measuring terminal tube is connected to a three-way tube.

3. A method for measuring coal bed gas pressure using the coal bed gas pressure measuring device according to claim 1 or 2, characterized in that The steps include: In the first step, after the coal seam drilling construction is completed, the sieve pipe is downwardly installed in the borehole with the sieve pipe and the pressure measuring pipe, and the tee pipe is located outside the borehole; The second step is to connect the air pump outlet pipe to the other port of the valve, open the valve, start the air pump, and observe the changes in the pressure gauge; In the third step, the airflow enters the pressure measuring tube, overcomes the spring force, pushes the baffle downward, and makes the baffle fit tightly against the inner ring platform to block the airflow channel; then the gas enters the rubber airbag through the one-way valve, gradually expanding the rubber airbag, and the rubber airbag is tightly attached to the inner wall of the drilled hole to form a seal; Step 4: When the pressure gauge reading reaches the set value, turn off the air pump, remove the air outlet pipe of the air pump from the valve, release the high-pressure gas in the pressure measuring tube, and then close the valve; The fifth step is to record the changes in the pressure gauge readings. When the pressure gauge readings remain stable for a period of time, stop observing and measure the coal seam gas pressure.

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