Energy-gathered pulsed abrasive jet coal seam anti-reflection device and method based on liquid nitrogen phase change

Abstract

The invention relates to the technical field of coal seam anti-reflection, in particular to an energy-gathered pulsed abrasive jet coal seam anti-reflection device and method based on liquid nitrogen phase change. In the anti-reflection device, the nitrogen cavity of the piston bin is filled with the liquid nitrogen, and the liquid nitrogen in the nitrogen cavity is heated to be quickly gasified, so that the nitrogen in the nitrogen cavity reaches the set pressure; the oil cavity is filled with high-pressure oil liquid, so that the oil liquid in the oil cavity reaches the set pressure; then the impact pipe is filled with particles through the particle filling mechanism, then the oil cavity is subjected to rapid pressure relief, the piston is rapidly pushed under the action of high-pressure nitrogen, the particles are pushed out of the impact pipe at a high speed through an impact head of the piston, and the high-speed particles hit the surface of a coal body; the coal rock is crushed through the impact energy of the high-speed particles; the process is repeated, different impacts on the coal rock are achieved till rock breaking setting requirements are met, rock breaking construction operation is safer, more efficient and more environmentally friendly, and the gas mining efficiency can be improved.

Description

Technical Field

[0001] This application relates to the field of coal seam permeability enhancement technology, and in particular to a coal seam permeability enhancement device and method based on liquid nitrogen phase change using focused pulse abrasive jet. Background Technology

[0002] In the process of coal seam mining and gas extraction, hard coal is inevitably encountered. A commonly used method for breaking coal is mechanical rock breaking, which mainly refers to the use of coal mining machine cutting drums or tunneling machine cutting teeth to cut and peel away the coal body through continuous mechanical force. Mechanical breaking has outstanding advantages such as continuous operation, high safety, and ease of automation, and has become the mainstream technology in modern coal mining.

[0003] However, traditional mechanical crushing methods suffer from problems such as severe wear of cutting tools, high energy consumption, and the risk of gas explosions caused by sparks when dealing with hard coal seams, interbedded rock, or highly ductile coal-rock complexes. This not only significantly increases tool replacement costs and downtime, reducing mining efficiency, but the resulting severe vibrations and frictional heat can also induce safety accidents such as coal and gas outbursts and dust explosions. How to significantly improve the crushing efficiency of complex coal seams and reduce equipment wear while ensuring safety is a key technological bottleneck for achieving safe and efficient coal mining.

[0004] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0005] The purpose of this application is to provide a device and method for enhancing the permeability of coal seams using concentrated pulse abrasive jet based on liquid nitrogen phase change, so as to solve or alleviate the problems existing in the prior art.

[0006] To achieve the above objectives, this application provides the following technical solution: A coal seam permeation enhancement device based on liquid nitrogen phase change pulsed abrasive jet, the device comprising a pulsed abrasive jet mechanism and a particle filling mechanism; The pulsed abrasive jet mechanism includes a piston chamber, in which an impact piston is guided and arranged. The impact piston divides the piston chamber into two parts: a nitrogen chamber and an oil chamber. The nitrogen chamber is filled with nitrogen gas, and the oil chamber is filled with oil. An impact tube is provided on one side of the piston chamber, and an impact head is provided on the impact piston. The impact head moves within the impact tube. The particle filling mechanism is used to fill particles into the impact tube. After the nitrogen chamber and oil chamber reach equilibrium, the oil chamber is depressurized, so that the piston drives the impact head to push the particles out of the impact tube and strike the coal surface.

[0007] As described above, the energy-concentrating pulse abrasive jet coal seam permeation enhancement device based on liquid nitrogen phase change preferably has a liquid nitrogen injection port provided in the piston chamber within the range of the corresponding nitrogen chamber. The liquid nitrogen injection port is connected to a liquid nitrogen storage tank through a pipeline, and a buffer tank is also provided in the pipeline between the liquid nitrogen storage tank and the liquid nitrogen injection port. A first solenoid valve is installed on the pipeline between the liquid nitrogen storage tank and the buffer tank, and a first pressure gauge and a second solenoid valve are installed on the pipeline between the liquid nitrogen injection port and the buffer tank. The liquid nitrogen in the liquid nitrogen storage tank first enters the buffer tank for temporary storage, and then the liquid nitrogen enters the nitrogen chamber from the buffer tank.

[0008] In the liquid nitrogen phase change-based focused pulse abrasive jet coal seam permeation enhancement device described above, preferably, a heater is provided in the nitrogen chamber of the piston chamber, the heater is connected to a temperature controller, and the temperature controller is used to control the heating power of the heater; A first pressure sensor is installed in the nitrogen chamber.

[0009] In the liquid nitrogen phase change-based focused pulse abrasive jet coal seam permeability enhancement device described above, preferably, the piston chamber is provided with an oil injection port and an oil drain port within the range of the corresponding oil chamber. The drain port is connected to the return port of the hydraulic oil tank through the unloading pipeline. A second pressure gauge and a third solenoid valve are installed on the unloading pipeline. A second pressure sensor is installed in the oil chamber.

[0010] In the liquid nitrogen phase change-based focused pulse abrasive jet coal seam permeation enhancement device described above, preferably, the oil injection port is connected to the oil outlet of the hydraulic oil tank through an oil injection pipeline, and a booster pump, a third pressure gauge and a fourth solenoid valve are installed on the oil injection pipeline.

[0011] In the liquid nitrogen phase change-based focused pulse abrasive jet coal seam permeation enhancement device described above, preferably, multiple guide grooves are provided on the side of the oil chamber away from the impact piston, and buffer blocks are provided in some of the guide grooves.

[0012] In the liquid nitrogen phase change-based focused pulse abrasive jet coal seam permeability enhancement device described above, preferably, a spring is provided between the buffer block and the bottom of the guide groove.

[0013] As described above, the liquid nitrogen phase change-based focused pulse abrasive jet coal seam permeation enhancement device preferably includes a particle filling mechanism comprising a particle filling chamber and a first variable frequency motor, wherein the particle filling chamber is mounted on the output shaft of the first variable frequency motor. The particle loading chamber has multiple particle loading positions. The particle loading chamber is rotated by an electric variable frequency motor so that the particle loading positions are aligned with the impact tube.

[0014] As described above, the liquid nitrogen phase change-based focused pulse abrasive jet coal seam permeation enhancement device preferably further includes a feeding mechanism for loading particles into a particle loading chamber. The feeding mechanism includes a second variable frequency motor, a crank, a connecting rod, a filling piston, and a particle chamber; the crank is connected to the output shaft of the second variable frequency motor, and the two ends of the connecting rod are respectively hinged to the crank and the filling piston. The loading piston is positioned at the top of the particle loading chamber, and the discharge port of the particle chamber is located between the loading piston and the particle loading chamber.

[0015] This application also provides a method for enhancing the permeability of coal seams using a focused pulse abrasive jet based on liquid nitrogen phase change. The method utilizes the aforementioned focused pulse abrasive jet coal seam enhancement device based on liquid nitrogen phase change, and includes the following steps: Step 1: Open the first solenoid valve to allow liquid nitrogen in the liquid nitrogen storage tank to flow to the buffer tank. At this time, observe the value of the first pressure gauge. When the value of the first pressure gauge reaches the set value, close the liquid nitrogen storage tank and the first solenoid valve. Step 2: Open the second solenoid valve to allow liquid nitrogen from the buffer tank to fill the nitrogen chamber; Step 3: Start the heater to vaporize the liquid nitrogen in the nitrogen chamber. Once the first pressure sensor reaches the set value, turn off the heater. Step 4: Open the fourth solenoid valve and start the booster pump to inject hydraulic oil into the oil chamber. The hydraulic oil pushes the impact piston to move, thereby compressing the nitrogen chamber. When the second pressure sensor reaches the set value, close the fourth solenoid valve and the booster pump. Step 5: Start the second variable frequency motor and push the particles into the particle filling position of the particle filling chamber through the filling piston. Then start the first variable frequency motor to drive the particle filling chamber to rotate, so that the next empty position is aligned with the filling piston, until the particle filling chamber rotates the particles to the impact tube position. Step 6: Open the third solenoid valve to depressurize the oil chamber. Under the pushing action of compressed nitrogen, the impact piston pushes the particles out of the impact tube, and the particles hit the surface of the coal body. Step 7: Repeat steps 1-6 until the set coal body crushing and permeability enhancement task is completed.

[0016] Compared with the closest prior art, the technical solution of this application has the following beneficial effects: In this permeation enhancement device, liquid nitrogen is introduced into the nitrogen chamber of the piston compartment and heated to rapidly vaporize the liquid nitrogen, thereby achieving a set pressure in the nitrogen chamber. High-pressure oil is introduced into the oil chamber to achieve a set pressure in the oil chamber, thus balancing the nitrogen chamber and the oil chamber. Then, particles are loaded into the impact tube through a particle filling mechanism, and the oil chamber is rapidly depressurized. Under the action of high-pressure nitrogen, the piston is rapidly pushed, causing the piston's impact head to push the particles out of the impact tube at high speed. The high-speed particles strike the surface of the coal body, thereby breaking the coal and rock through the impact energy of the high-speed particles. The above process is repeated to achieve different impacts on the coal and rock until the rock breaking requirements are met.

[0017] This permeability enhancement device uses particle crushing, completely eliminating the problem of wear and tear on traditional mechanical coal crushing blades. Moreover, the oil in the device can be reused, and the nitrogen emissions will not have a significant impact on the coal mining environment. This makes rock breaking operations safer, more efficient, and more environmentally friendly, and helps improve gas extraction efficiency. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein: Figure 1 This is a schematic diagram of the structure of an antireflection device provided according to some embodiments of this application; Figure 2 This is a detailed schematic diagram of a piston chamber provided according to some embodiments of this application; Figure 3 for Figure 2 Cross-sectional view of AA in the middle; Figure 4 This is a schematic diagram of the feeding mechanism provided according to some embodiments of this application; Figure 5 This is a schematic diagram of the structure of a particle loading chamber provided according to some embodiments of this application.

[0019] Explanation of reference numerals in the attached figures: 1. Liquid nitrogen storage tank; 2. Pressure boosting valve; 3. Safety valve; 4. Vent valve; 5. First solenoid valve; 6. Buffer tank; 7. First pressure gauge; 8. Second solenoid valve; 9. Temperature controller; 10. Switch; 11. Heating plate; 12. First pressure sensor; 13. Second pressure sensor; 14. Particle chamber; 15. Outlet velocity detector; 16. Second pressure gauge; 17. Third solenoid valve; 18. Hydraulic oil tank; 19. Ball valve; 20. Pressure boosting pump; 21. Third 21. Pressure gauge; 22. Fourth solenoid valve; 23. Central control system; 24. Liquid nitrogen injection port; 25. Nitrogen chamber; 26. Liquid nitrogen buffer chamber; 27. Impact piston; 28. Oil chamber; 29. ​​Buffer block; 30. Oil buffer chamber; 31. Feeding mechanism; 311. Filling piston; 312. Connecting rod; 313. Crank; 32. Particle filling bin; 33. First variable frequency motor; 34. Oil inlet; 35. Oil drain port; 36. Second variable frequency motor; 37. Spring; 38. Piston chamber. Detailed Implementation

[0020] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of interpretation and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present application without departing from the scope or spirit thereof. For example, a feature represented or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present application encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0021] In the following description, the terms "first / second / third" are used merely to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing embodiments of this disclosure only and is not intended to limit this disclosure.

[0023] In the description of this application, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and do not require that this application be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. The terms "connected," "linked," and "set up" used in this application should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; direct connections or indirect connections through intermediate components; wired connections, radio connections, or wireless communication signal connections. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0024] The present application will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0025] According to specific embodiments of this application, such as Figure 1-5 As shown, this application provides a coal seam permeability enhancement device based on liquid nitrogen phase change using a focused pulse abrasive jet. The permeability enhancement device includes a pulse abrasive jet mechanism and a particle filling mechanism.

[0026] The pulsed abrasive jet mechanism includes a piston chamber 38, in which an impact piston 27 is guided.

[0027] The impact piston 27 divides the piston chamber 38 into two parts: a nitrogen chamber 25 and an oil chamber 28. The nitrogen chamber 25 is filled with nitrogen, and the oil chamber 28 is filled with oil.

[0028] An impact tube is provided on one side of the piston chamber 38, and an impact head is provided on the impact piston 27. The impact head moves guided within the impact tube. In one embodiment of this application, the impact head is detachably disposed on one side of the impact piston 27. Specifically, pin holes can be provided on both sides of the impact piston 27 and the impact head, in which case the impact head and the impact piston 27 are connected by a fixing pin; alternatively, a threaded hole can be provided on one side of the impact piston 27, and a threaded post can be machined on one side of the impact head. In this case, the threaded post on the side of the impact head is installed in the threaded hole on the side of the impact piston 27, thereby achieving a detachable connection between the impact head and the impact piston 27. This arrangement facilitates quick and convenient replacement of the impact head after wear.

[0029] The particle filling mechanism is used to fill particles into the impact tube. After the nitrogen chamber 25 and the oil chamber 28 reach equilibrium, the oil chamber 28 is depressurized, so that the piston drives the impact head to push the particles out of the impact tube and hit the coal surface.

[0030] In this permeation enhancement device, liquid nitrogen is filled into the nitrogen chamber 25 of the piston chamber 38, and the liquid nitrogen in the nitrogen chamber 25 is heated to rapidly vaporize the liquid nitrogen, thereby bringing the nitrogen in the nitrogen chamber 25 to a set pressure. High-pressure oil is filled into the oil chamber 28, bringing the oil in the oil chamber 28 to a set pressure. This brings the nitrogen chamber 25 and the oil chamber 28 into balance. Then, particles are loaded into the impact tube through the particle filling mechanism, and the oil chamber 28 is rapidly depressurized. Under the action of high-pressure nitrogen, the piston is rapidly pushed, causing the piston's impact head to push the particles out of the impact tube at high speed. The high-speed particles strike the surface of the coal body, thereby breaking the coal and rock through the impact energy of the high-speed particles. The above process is repeated to achieve different impacts on the coal and rock until the rock breaking requirements are met.

[0031] This permeability enhancement device uses particle crushing, completely eliminating the problem of wear and tear on traditional mechanical coal crushing blades. Moreover, the oil in the device can be reused, and the nitrogen emissions will not have a significant impact on the coal mining environment. This makes rock breaking operations safer, more efficient, and more environmentally friendly, and helps improve gas extraction efficiency.

[0032] The piston chamber 38 is provided with a liquid nitrogen injection port 24 within the range of the nitrogen chamber 25. The liquid nitrogen injection port 24 is connected to the liquid nitrogen storage tank 1 through a pipeline. A buffer tank 6 is also provided on the pipeline between the liquid nitrogen storage tank 1 and the liquid nitrogen injection port 24. A first solenoid valve 5 is provided on the pipeline between the liquid nitrogen storage tank 1 and the buffer tank 6. A first pressure gauge 7 and a second solenoid valve 8 are provided on the pipeline between the buffer tank 6 and the liquid nitrogen injection port 24. The liquid nitrogen in the liquid nitrogen storage tank 1 first enters the buffer tank 6 for temporary storage, and then the liquid nitrogen enters the nitrogen chamber 25 from the buffer tank 6.

[0033] In this embodiment, the first pressure gauge 7 is located upstream of the second solenoid valve 8. When liquid nitrogen needs to be filled into the nitrogen chamber 25, the liquid nitrogen storage tank 1 and the first solenoid valve 5 are opened first, so that the liquid nitrogen in the liquid nitrogen storage tank 1 flows to the buffer tank 6. At this time, the value of the first pressure gauge 7 is observed. When the value of the first pressure gauge 7 reaches the set value, the liquid nitrogen storage tank 1 and the first solenoid valve 5 are closed. Then the second solenoid valve 8 is opened. The liquid nitrogen in the buffer tank 6 is in a high-pressure state. The high-pressure liquid nitrogen automatically flows to the low-pressure environment of the nitrogen chamber 25. By observing the value of the first pressure gauge 7, the flow state of the liquid nitrogen is determined. When the value of the first pressure gauge 7 drops to the set range value, the second solenoid valve 8 is closed. At this time, the liquid nitrogen is filled into the nitrogen chamber 25.

[0034] By setting a buffer tank 6 between the liquid nitrogen storage tank 1 and the liquid nitrogen injection port 24, the liquid nitrogen first enters the buffer tank 6 and then enters the nitrogen chamber 25 from the buffer tank 6, which can ensure higher safety during the liquid nitrogen filling process.

[0035] In this embodiment, a liquid nitrogen buffer chamber 26 is arranged around the periphery of the nitrogen chamber 25 in the piston chamber 38. The liquid nitrogen buffer chamber 26 is interconnected with the nitrogen chamber 25 to increase the volume of the nitrogen chamber 25. A first pressure sensor is arranged in the liquid nitrogen buffer chamber 26 to monitor the pressure changes in the liquid nitrogen buffer chamber 26 and the nitrogen chamber 25 in real time.

[0036] In this embodiment, the liquid nitrogen storage tank 1 is equipped with a pressure boosting valve 2, a safety valve 3 and a venting valve 4 to ensure that the liquid nitrogen storage tank 1 has sufficient safety.

[0037] A heater is installed in the nitrogen chamber 25 of the piston compartment 38. The heater is connected to a temperature controller 9, which controls the heating power of the heater. A first pressure sensor is installed in the nitrogen chamber 25.

[0038] In this embodiment, the temperature controller 9 is located outside the piston chamber 38, and the heater is located inside the piston chamber 38. The heater and the temperature controller 9 are connected by a wire, and a switch 10 is installed on the wire. When liquid nitrogen is filled into the nitrogen chamber 25, the switch 10 is turned on, and the heater is heated by the temperature controller 9 to vaporize the liquid nitrogen. The pressure in the nitrogen chamber 25 is monitored in real time by the first pressure sensor. After the pressure in the nitrogen chamber 25 reaches the set value, the switch 10 is turned off to stop the heater from heating.

[0039] In this embodiment, the heater can be a heating plate 11 structure. The heating plate 11 has a large heating area, which is more conducive to heating liquid nitrogen and vaporizing the liquid nitrogen.

[0040] The piston chamber 38 is provided with an oil inlet 34 and an oil outlet 35 within the range of the corresponding oil chamber 28; the oil outlet 35 is connected to the return port of the hydraulic oil tank 18 through the oil discharge pipeline, and a second pressure gauge 16 and a third solenoid valve 17 are provided on the oil discharge pipeline; a second pressure sensor 12, a first pressure sensor 13 are provided in the oil chamber 28.

[0041] In this embodiment, a ball valve 19 is also provided on the oil injection line. When using the anti-reflection device, the ball valve 19 is opened first. This arrangement is to improve the safety of the anti-reflection device.

[0042] When it is necessary to depressurize the oil chamber 28, the third solenoid valve 17 is opened, and the hydraulic oil in the oil chamber 28 enters the hydraulic oil tank 18 through the depressurization pipeline. When the second pressure gauge 16 reaches the set pressure value, the depressurization is completed, and then the third solenoid valve 17 is closed.

[0043] In this embodiment, an oil buffer chamber 30 is arranged around the periphery of the oil chamber 28 in the piston chamber 38. The oil buffer chamber 30 is interconnected with the oil chamber 28 to increase the volume of the oil chamber 28. A second pressure sensor 12 and a first pressure sensor 13 are arranged in the oil buffer chamber 30 to monitor the pressure changes in the oil buffer chamber 30 and the oil chamber 28 in real time.

[0044] In this embodiment, an exit velocity detector 15 is provided near the outlet of the impact tube on the piston chamber 38 to detect the initial velocity of the particles emitted from the impact tube.

[0045] The anti-reflection device also includes a central control system 23. The first pressure sensor, the second pressure sensor 12, the first pressure sensor 13, and the outlet velocity detector 15 are all electrically connected to the central control system 23 to transmit monitoring signals to the central control system 23. The central control system 23 performs calculations and analyses on the first pressure sensor, the second pressure sensor 12, the first pressure sensor 13, and the outlet velocity detector 15 to optimize and adjust the allowable parameters of the anti-reflection device, thereby reducing the energy consumption of the anti-reflection device and improving the particle impact efficiency.

[0046] The oil inlet 34 is connected to the oil outlet of the hydraulic oil tank 18 via an oil inlet pipeline. A booster pump 20, a third pressure gauge 21, and a fourth solenoid valve 22 are installed on the oil inlet pipeline. In this embodiment, when oil needs to be injected into the oil chamber 28, the fourth solenoid valve 22 is opened, and the booster pump 20 is started to inject hydraulic oil into the oil chamber 28. When the third pressure gauge 21 reaches the set pressure value, the fourth solenoid valve 22 is closed, and the booster pump 20 is turned off.

[0047] Multiple guide grooves are provided on the side of the oil cavity 28 away from the impact piston 27, and buffer blocks 29 are provided in some of the guide grooves.

[0048] In this embodiment, four guide grooves are provided on the side of the oil chamber 28 away from the impact piston 27. Buffer blocks 29 are provided in two of the opposite guide grooves, while the other two guide grooves are left empty to ensure the smooth flow of oil in the oil chamber 28.

[0049] A spring 37 is provided between the buffer block 29 and the bottom of the guide groove. In this embodiment, one end of the spring 37 is fixed to the end face of the buffer block 29, and the other end is fixed to the bottom of the guide groove. After the impact piston 27 pushes out the particle, the impact piston 27 still has a large speed. When the impact piston 27 continues to move, it hits the buffer block 29. The buffer block compresses the spring 37 to play a buffering role, thereby preventing the impact piston 27 from directly impacting the piston chamber 38. This can greatly reduce the kinetic energy of the impact piston 27 after hitting the particle, so as to ensure that the piston chamber 38 has a better service life and durability.

[0050] The particle filling mechanism includes a particle filling chamber 32 and a first variable frequency motor 33. The particle filling chamber 32 is mounted on the output shaft of the first variable frequency motor 33. The particle filling chamber 32 has multiple particle filling positions. The particle filling chamber 32 is rotated by the variable frequency motor so that the particle filling positions are aligned with the impact tube.

[0051] In this embodiment, the particle filling chamber 32 is a disk-shaped structure, with multiple particle filling positions arranged around the outer ring of the particle filling chamber 32. Each particle filling position can be filled with one particle. The particles can be particles made of materials with high hardness, such as steel particles or iron particles.

[0052] The anti-reflection device also includes a feeding mechanism 31, which is used to load particles into the particle filling chamber 32. The feeding mechanism 31 includes a second variable frequency motor 36, a crank 313, a connecting rod 312, a filling piston 311, and a particle chamber 14. The crank 313 is connected to the output shaft of the second variable frequency motor 36, and the two ends of the connecting rod 312 are respectively hinged to the crank 313 and the filling piston 311. The filling piston 311 is aligned with the particle filling position at the top of the particle filling chamber 32, and the discharge port of the particle chamber 14 is located between the filling piston 311 and the particle filling chamber 32.

[0053] In this embodiment, both the particle filling mechanism and the feeding mechanism 31 are installed at the impact tube outlet position of the piston chamber 38; a guide hole is provided in the piston chamber 38 at the position corresponding to the feeding piston 311 of the feeding mechanism 31 to guide the feeding piston 311.

[0054] When it is necessary to fill the particles, the feeding mechanism 31 and the particle filling mechanism work together. The particles in the particle chamber 14 first fall between the filling piston 311 and the top particle filling position of the particle filling chamber 32. Then, the second variable frequency motor 36 drives the crank 313 to rotate, and the connecting rod 312 pushes the filling piston 311 to move, so that the filling piston 311 pushes the particles into the particle filling position of the particle filling chamber 32. Then, the first variable frequency motor 33 drives the particle filling chamber 32 to rotate, so that the next empty particle filling position is aligned with the filling piston. The above process is repeated, that is, the particles are installed in the column filling position of the particle filling chamber 32.

[0055] This application also provides a method for enhancing the permeability of coal seams using a focused pulse abrasive jet based on liquid nitrogen phase change. The method utilizes the aforementioned focused pulse abrasive jet coal seam enhancement device based on liquid nitrogen phase change, and includes the following steps: Step 1: Open the first solenoid valve 5 to allow the liquid nitrogen in the liquid nitrogen storage tank 1 to flow into the buffer tank 6. At this time, observe the value of the first pressure gauge 7. When the value of the first pressure gauge 7 reaches the set value, close the liquid nitrogen storage tank 1 and the first solenoid valve 5. In this embodiment, the liquid nitrogen storage tank 1 is a self-pressurizing storage tank. After opening the first solenoid valve 5 and the hydraulic storage tank, the liquid nitrogen can automatically flow into the buffer tank 6.

[0056] Step 2: Open the second solenoid valve 8 to allow liquid nitrogen in the buffer tank 6 to fill the nitrogen chamber 25. In this embodiment, since the liquid nitrogen in the buffer tank 6 is under high pressure, the high-pressure liquid nitrogen automatically flows to the low-pressure nitrogen chamber 25. By observing the value of the first pressure gauge 7, the flow state of the liquid nitrogen is determined. When the value of the first pressure gauge 7 drops to the set range, the second solenoid valve 8 is closed, and the liquid nitrogen filling into the nitrogen chamber 25 is completed.

[0057] Step 3: Start the heater to vaporize the liquid nitrogen in the nitrogen chamber 25. When the first pressure sensor reaches the set value, turn off the heater. In this embodiment, when the heater is started, the vaporization of liquid nitrogen will push the impact piston 27. At this time, no particles are placed in the particle loading position of the particle loading chamber 32 aligned with the impact tube to avoid directly pushing out the particles in this step. In this step, the vaporization of liquid nitrogen is accelerated by setting the heating plate 11 so that a large amount of nitrogen can quickly fill the nitrogen chamber 25.

[0058] Step 4: Open the fourth solenoid valve 22 and start the booster pump 20 to inject hydraulic oil into the oil chamber 28. The hydraulic oil pushes the impact piston 27 to move, thereby compressing the nitrogen chamber 25. When the second pressure sensor 12 and the first pressure sensor 13 reach the set value, close the fourth solenoid valve 22 and the booster pump 20. In this embodiment, the second pressure sensor 12 and the first pressure sensor 13 can monitor the pressure in the oil chamber 28 in real time, and the third pressure gauge 21 can monitor the pressure in the oil injection line in real time. The two can be mutually calibrated, so that after the oil chamber 28 reaches the set pressure value, the fourth solenoid valve 22 and the booster pump 20 are closed. At this time, both the nitrogen chamber 25 and the oil chamber 28 are in a high-pressure state.

[0059] At this time, the pressure of the nitrogen chamber 25 and the oil chamber 28 can be monitored in real time through the central control system 23 to ensure the permissible stability of the anti-reflection device.

[0060] Step 5: Start the second variable frequency motor 36 and push the particles into the particle loading position of the particle loading chamber 32 through the loading piston 311. Then start the first variable frequency motor 33 to drive the particle loading chamber 32 to rotate, so that the next empty position is aligned with the loading piston 311, until the particle loading chamber 32 rotates the particles to the impact tube position. Step 6: Open the third solenoid valve 17 to depressurize the oil chamber 28. Under the driving force of compressed nitrogen, the impact piston 27 pushes the particles out of the impact tube, and the particles hit the surface of the coal body. In this embodiment, after opening the third solenoid valve 17, the high-pressure oil in the oil chamber 28 flows back to the hydraulic oil tank 18 through the drain port 35. At this time, under the driving force of compressed nitrogen, the impact piston 27 pushes the particles towards the coal body at extremely high speed to break the rock. After the particles are pushed out, the impact piston 27 hits the buffer block 29, which provides better buffering.

[0061] Step 7: Repeat steps 1-6 until the set coal body crushing and permeability enhancement task is completed.

[0062] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A coal seam permeation enhancement device based on liquid nitrogen phase change using focused pulse abrasive jets, characterized in that, The antireflection device includes a pulsed abrasive jet mechanism and a particle filling mechanism; The pulsed abrasive jet mechanism includes a piston chamber, in which an impact piston is guided and arranged. The impact piston divides the piston chamber into two parts: a nitrogen chamber and an oil chamber. The nitrogen chamber is filled with nitrogen gas, and the oil chamber is filled with oil. An impact tube is provided on one side of the piston chamber, and an impact head is provided on the impact piston. The impact head moves within the impact tube. The particle filling mechanism is used to fill particles into the impact tube. After the nitrogen chamber and oil chamber reach equilibrium, the oil chamber is depressurized, so that the piston drives the impact head to push the particles out of the impact tube and strike the coal surface.

2. The energy-concentrating pulsed abrasive jet coal seam permeation enhancement device based on liquid nitrogen phase change according to claim 1, characterized in that, The piston chamber is equipped with a liquid nitrogen injection port within the range of the corresponding nitrogen chamber. The liquid nitrogen injection port is connected to the liquid nitrogen storage tank through a pipeline. A buffer tank is also installed on the pipeline between the liquid nitrogen storage tank and the liquid nitrogen injection port. A first solenoid valve is installed on the pipeline between the liquid nitrogen storage tank and the buffer tank, and a first pressure gauge and a second solenoid valve are installed on the pipeline between the liquid nitrogen injection port and the buffer tank. The liquid nitrogen in the liquid nitrogen storage tank first enters the buffer tank for temporary storage, and then the liquid nitrogen enters the nitrogen chamber from the buffer tank.

3. The coal seam permeation enhancement device based on liquid nitrogen phase change using focused pulse abrasive jet as described in claim 2, characterized in that, A heater is installed in the nitrogen chamber of the piston compartment. The heater is connected to a temperature controller, which is used to control the heating power of the heater. A first pressure sensor is installed in the nitrogen chamber.

4. The coal seam permeation enhancement device based on liquid nitrogen phase change using focused pulse abrasive jet as described in claim 3, characterized in that, The piston chamber is provided with an oil inlet and an oil outlet within the range of the corresponding oil chamber; The drain port is connected to the return port of the hydraulic oil tank through the unloading pipeline. A second pressure gauge and a third solenoid valve are installed on the unloading pipeline. A second pressure sensor is installed in the oil chamber.

5. The coal seam permeation enhancement device based on liquid nitrogen phase change using focused pulse abrasive jet as described in claim 4, characterized in that, The oil filling port is connected to the oil outlet of the hydraulic oil tank through an oil filling pipeline. A booster pump, a third pressure gauge, and a fourth solenoid valve are installed on the oil filling pipeline.

6. The energy-concentrating pulsed abrasive jet coal seam permeation enhancement device based on liquid nitrogen phase change according to claim 5, characterized in that, Multiple guide grooves are provided on the side of the oil chamber away from the impact piston, and buffer blocks are provided in some of the guide grooves.

7. The coal seam permeation enhancement device based on liquid nitrogen phase change using focused pulse abrasive jet as described in claim 6, characterized in that, A spring is provided between the buffer block and the bottom of the guide groove.

8. The energy-concentrating pulsed abrasive jet coal seam permeation enhancement device based on liquid nitrogen phase change according to claim 7, characterized in that, The particle filling mechanism includes a particle filling chamber and a first variable frequency motor, wherein the particle filling chamber is mounted on the output shaft of the first variable frequency motor. The particle loading chamber has multiple particle loading positions. The particle loading chamber is rotated by an electric variable frequency motor so that the particle loading positions are aligned with the impact tube.

9. The coal seam permeation enhancement device based on liquid nitrogen phase change using focused pulse abrasive jet as described in claim 7, characterized in that, The anti-reflection device also includes a feeding mechanism for loading particles into a particle loading chamber. The feeding mechanism includes a second variable frequency motor, a crank, a connecting rod, a filling piston, and a particle chamber; the crank is connected to the output shaft of the second variable frequency motor, and the two ends of the connecting rod are respectively hinged to the crank and the filling piston. The loading piston is positioned at the top of the particle loading chamber, and the discharge port of the particle chamber is located between the loading piston and the particle loading chamber.

10. A method for enhancing the permeability of coal seams using focused pulse abrasive jet based on liquid nitrogen phase change, characterized in that, The enhanced permeability method uses the liquid nitrogen phase change-based focused pulse abrasive jet coal seam enhanced permeability device as described in claim 9, and the enhanced permeability method includes the following steps: Step 1: Open the first solenoid valve to allow liquid nitrogen in the liquid nitrogen storage tank to flow to the buffer tank. At this time, observe the value of the first pressure gauge. When the value of the first pressure gauge reaches the set value, close the liquid nitrogen storage tank and the first solenoid valve. Step 2: Open the second solenoid valve to allow liquid nitrogen from the buffer tank to fill the nitrogen chamber; Step 3: Start the heater to vaporize the liquid nitrogen in the nitrogen chamber. Once the first pressure sensor reaches the set value, turn off the heater. Step 4: Open the fourth solenoid valve and start the booster pump to inject hydraulic oil into the oil chamber. The hydraulic oil pushes the impact piston to move, thereby compressing the nitrogen chamber. When the second pressure sensor reaches the set value, close the fourth solenoid valve and the booster pump. Step 5: Start the second variable frequency motor and push the particles into the particle filling position of the particle filling chamber through the filling piston. Then start the first variable frequency motor to drive the particle filling chamber to rotate, so that the next empty position is aligned with the filling piston, until the particle filling chamber rotates the particles to the impact tube position. Step 6: Open the third solenoid valve to depressurize the oil chamber. Under the pushing action of compressed nitrogen, the impact piston pushes the particles out of the impact tube, and the particles hit the surface of the coal body. Step 7: Repeat steps 1-6 until the set coal body crushing and permeability enhancement task is completed.

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