A device and method capable of realizing adaptive adjustment of coal seam hole expansion angle

Abstract

The present invention belongs to the technical field of air jet and coal seam pressure relief and permeability enhancement, and in particular relates to a device and method capable of realizing adaptive adjustment of coal seam hole expansion angle, comprising an air compressor, a high-pressure resistant pipeline connected to the air compressor, the high-pressure resistant pipeline connected to a drill pipe through an air braid, a hole expander is provided at the end of the drill pipe, a drill bit is provided at the end of the hole expander, and also comprises a resin ball arranged in the central channel of the drill pipe, the hole expander comprises a central flow channel and a straight flow channel nozzle, a hole expansion assembly is provided at the end of each straight flow channel nozzle, two symmetrical nozzles are provided outside the hole expander shell, and the nozzles are connected to the straight flow channel nozzle; the present invention can realize adaptive adjustment of hole expansion angle, can effectively avoid hole expansion blank zone, and can make full use of the characteristics of ground stress through precise adjustment of hole expansion angle to expand holes with regular holes and larger diameters, thereby increasing the pressure relief and permeability enhancement effect of hole expansion under the same working conditions, and has wider applicability.

Description

Technical Field

[0001] The invention belongs to the technical field of air jet and coal seam pressure relief and permeability enhancement, and in particular relates to a device and method capable of realizing self-adaptive adjustment of coal seam hole expansion angle. Background Art

[0002] As the main energy source in my country, coal is the "ballast stone" of energy supply. In the context of low-carbon economy, my country's energy structure optimization strategy emphasizes resolutely controlling the total growth of energy consumption. As a bottom-line energy guarantee, coal's efficient mining is extremely critical to my country's energy security. However, more than 70% of my country's coal seams are low-permeability coal seams, and gas extraction is difficult and time-consuming. The low gas extraction rate leads to an imbalance in coal mining, which seriously curbs the release of coal production capacity. At present, hydraulic measures are widely studied and applied in the field of coal seam permeability enhancement due to mature technical equipment and flexible application. Specific hydraulic measures include hydraulic slitting, hydraulic punching, and hydraulically driven mechanical tools with water as the working medium to break coal and increase permeability. For example, the publication number CN219808956U, the invention name is "a coal seam reamer", which uses high-pressure water pressure to expand the reamer through a compressed fast compression spring to break coal and increase permeability over a large range. The pressure required for this device to use pure water jets is relatively high, and the safety of the equipment is low. In addition, the length of the reaming tool is limited by the current material. A tool that is too long is prone to brittle breakage. Therefore, the current reaming tool cannot achieve large-diameter reaming. At the same time, if the peeled coal body cannot be removed in time, there is also a risk of clogging the closing device; the publication number is CN109630022A, and the name of the invention is "A composite drill bit", which also uses high pressure to provide the power for tool closing. In addition to the above-mentioned advantages and disadvantages, this device can more accurately control the closing of the tool by setting the pressure conversion in stages. However, when constructing through-layer drilling and reaming, it is inevitable that there will be a blank zone for reaming, and at the same time, the ground stress cannot be fully utilized. After the reaming construction, due to the intrusion of water into the coal seam, the reaming shape is more susceptible to the action of ground stress, resulting in deformation, creep, and collapse. Summary of the invention

[0003] The purpose of the present invention is to address the above-mentioned problems. Based on the existing equipment and technology, the present invention proposes a reaming device and method that uses low-pressure air as a power medium to achieve self-adaptation of the coal seam reaming angle. The safety of the device is improved; and the new reamer can maximize the use of ground stress to achieve the stability of the reaming shape by adjusting the nozzle angle. At the same time, the Laval nozzle designed and developed based on aerodynamics and installed on the reamer can achieve high supersonic ejection of low-pressure gas jets, thereby achieving large-diameter reaming and permeability enhancement of coal seams, achieving efficient extraction of coal seam gas, and promoting the release of coal production capacity.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A device capable of realizing adaptive adjustment of coal seam hole expansion angle comprises an air compressor, a high-pressure resistant pipeline connected to the outlet of the air compressor, the outlet of the high-pressure resistant pipeline is connected to a drill pipe through an air braid, the drill pipe is controlled by a drilling rig, a hole expander is arranged at the end of the drill pipe, a drill bit is arranged at the end of the hole expander, and a resin ball is arranged in the central channel of the drill pipe, the relationship among the diameter d1 of the resin ball, the diameter d2 of the air braid channel, and the diameter d3 of the drill pipe channel is d3>d1>d2; the hole expander comprises a central flow channel located in the center and a straight flow channel nozzle arranged in parallel at the upper and lower parts of the central flow channel, a hole expanding assembly is arranged at the end of each straight flow channel nozzle, two symmetrical nozzles are arranged outside the hole expander shell, and the nozzles are connected to the straight flow channel nozzles; a control system and an angle adaptive adjustment device are also included.

[0006] Furthermore, the reaming assembly includes a radial nozzle connected to the straight channel nozzle and vertically movably connected, a ratchet is provided on the outer sleeve of the radial nozzle, a Laval nozzle is provided at the end of the radial nozzle and is inclined outwardly connected to the straight channel nozzle, the Laval nozzle is located in an elastic block inside the reamer shell, the elastic block is located in the nozzle angle adjustment area in the reamer, and a straight channel is provided in the center of the elastic block for placing the Laval nozzle.

[0007] Furthermore, the angle adaptive adjustment device includes an internal gear inserted in the air inlet end of the radial nozzle and interference fit with the inner wall of the radial nozzle, a spoke gear meshing with the internal gear, the center of the spoke gear is fixedly connected to the output end of the servo motor, and also includes a gyroscope. The servo motor, gyroscope and control system are all arranged in a cylindrical protective shell, and the protective shell is inserted at the end of the straight channel nozzle.

[0008] Furthermore, the control system includes a PLC integrated control board, and the gyroscope and the servo motor are both electrically connected to the PLC integrated control board.

[0009] Furthermore, the ratchet is an inner edge ratchet, including an outer inner edge bevel tooth surface and a central circular arc surface. The circular arc surface is fixed with a blocking block and an elastic sheet that engage with the inner edge bevel tooth surface through large and small pins respectively. The bottom of the inner edge bevel tooth surface is movably connected to the circular arc surface, and the circular arc surface is fixedly connected to the outer wall of the radial nozzle.

[0010] Furthermore, the center of the Laval nozzle is composed of a contraction section, a throat and an expansion section in sequence, and the outlet of the expansion section is connected to a straight channel in the center of the elastic block.

[0011] A method for adjusting a device capable of realizing adaptive adjustment of a coal seam hole expansion angle comprises the following steps:

[0012] S1. Before expanding the coal seam, first fix the pipeline and make the drill drill to the coal seam position;

[0013] S2. Place the resin ball into the inner hole of the drill pipe and re-thread the air braid to the drill pipe;

[0014] S3. Adjust the air compressor to 0.5MPa, open the valve on the air braid, and count for 1-2 minutes according to the drilling depth, waiting for the resin balls to be transported to the gas inlet end of the center flow channel of the reamer and block the center flow channel;

[0015] S4. Adjust the air compressor to the required working pressure, and the gas enters through the straight channel nozzles on both sides of the reamer inlet end;

[0016] S5. The angle adaptive adjustment device drives the Laval nozzle to rotate by meshing with the gear installed in the ratchet radial flow channel tube to achieve angle adjustment;

[0017] S6. After passing through the straight channel nozzle, the gas enters the ratchet radial channel tube, and then is accelerated to hypersonic speed through the Laval nozzle and ejected for hole expansion.

[0018] Mechanism: The present invention realizes the pressure relief and permeability enhancement work of underground air jet hole expansion with adaptive angle. This technology uses compressed air as the power source, which can maintain the original mechanical properties of the coal body to the greatest extent, so that the shape of the expanded hole can be maintained for a long time. Compared with hydraulic technology, it can effectively solve problems such as drill sticking, hole collapse, creep, etc. The central flow channel set inside the reamer can realize the integration of "drilling-expansion" in combination with resin balls. The angle adaptive adjustment device installed inside the reamer can automatically adjust the nozzle expansion angle according to the coal seam information, effectively avoiding the appearance of the expansion blank zone. The Laval nozzle designed based on aerodynamics of this device can accelerate air to hypersonic speed, has high impact kinetic energy, and can realize large-scale and efficient crushing of the coal body. The invention solves the coal mining caused by low gas extraction efficiency in soft, low-permeability and high-gas mines. The working pressure of this equipment is low, the equipment is highly safe, and it is easy to operate.

[0019] The present invention has the advantages that:

[0020] 1. In view of the fact that water is currently used as a working medium or power source, it will inevitably infiltrate the coal seam, thereby causing the deterioration of the mechanical properties of the coal body, causing drilling and expansion creep, hole collapse and other phenomena, and reducing the efficiency of coal seam gas extraction; the puncher designed in the present invention uses compressed air as a power source and working medium, which can maintain the mechanical properties of the coal body to a great extent and is not prone to hole collapse and other phenomena;

[0021] 2. An angle adaptive adjustment device structure is added inside the designed hole expander. The required hole expansion angle is measured by a gyroscope, and the radial nozzle is driven by a servo motor to rotate. This can realize the adaptive adjustment of the nozzle angle, effectively avoid the appearance of the hole expansion blank zone, and realize efficient hole expansion;

[0022] 3. The Laval nozzle used in the invention is developed based on aerodynamic principles and can achieve supersonic gas outlet velocity (v>700m / s) under low-pressure air (P<1.0MPa), and can achieve large-scale and efficient crushing of soft coal seams (solidity coefficient f<0.3). BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention.

[0024] Figure 2 It is a schematic diagram of the cross-sectional structure of the reamer in the present invention.

[0025] Figure 3 It is a structural schematic diagram of the hole expansion component and the angle adaptive adjustment device in the present invention.

[0026] Figure 4 It is a schematic diagram of the ratchet structure in the present invention.

[0027] Figure 5 It is a structural schematic diagram of the angle adaptive adjustment device in the present invention.

[0028] Figure 6 It is a structural schematic diagram of the Laval nozzle in the present invention.

[0029] Figure 7 It is a structural schematic diagram of the elastic block in the present invention.

[0030] Figure 8 It is a schematic diagram of the structure of the resin beads in the present invention.

[0031] Fig. 9 It is a schematic diagram of the structure of the reamer in the present invention.

[0032] Fig.10 This is a working state diagram of the angle adaptive adjustment device and the ratchet in the present invention. DETAILED DESCRIPTION

[0033] like Figure 1-10As shown, a device capable of realizing adaptive adjustment of coal seam hole expansion angle comprises an air compressor 1, a high pressure resistant pipeline 2 connected to the outlet of the air compressor, the outlet of the high pressure resistant pipeline is connected to a drill pipe 4 through an air braid 3, the drill pipe is controlled by a drilling rig 5, an expander 6 is provided at the end of the drill pipe, a drill bit 7 is provided at the end of the expander, and a resin ball 21 is provided in the central hole of the drill pipe, the relationship between the diameter d1 of the resin ball, the diameter d2 of the air braid hole, and the diameter d3 of the drill pipe hole is d3>d1>d2; the expander comprises a hole located in the middle The central flow channel 6b and the straight flow channel nozzle 6a arranged in parallel at the upper and lower parts of the central flow channel, each straight flow channel nozzle end is provided with a reaming assembly, the reaming assembly includes a radial nozzle 6f connected to the straight flow channel nozzle and vertically movably connected, the radial nozzle outer sleeve is provided with a ratchet 6c, the radial nozzle end is provided with a Laval nozzle 6d inclined outwardly connected to the straight flow channel nozzle, the Laval nozzle is located in the elastic block 19 in the reamer housing 22, the elastic block is located in the nozzle angle adjustment area in the reamer, and the elastic block is located in the nozzle angle adjustment area in the reamer. A straight channel 20 for placing a Laval nozzle is provided at the center of the force block. The elastic block is provided to prevent coal slag in the borehole from entering the reamer housing from the nozzle and affecting subsequent work. The deformation of the elastic block is less than the torque when the Laval nozzle rotates, that is, to ensure that the Laval nozzle can rotate and spray normally; two symmetrical nozzles are provided on the outside of the reamer housing, and the nozzle opening is larger than the inner diameter of the straight channel in the elastic block. This is to meet the needs of the Laval nozzle during rotational spraying, and the nozzle is connected to the straight channel nozzle; it also includes a control system and an angle adaptive adjustment device 6e, the angle adaptive adjustment device includes an internal gear 14 inserted in the air inlet end of the radial nozzle and having an interference fit with the inner wall of the radial nozzle, a spoke gear 15 meshing with the internal gear, the center of the spoke gear is fixedly connected to the output end of the servo motor, and also includes a gyroscope, the servo motor, the gyroscope and the control system are all arranged in a cylindrical protective shell, and the protective shell is inserted at the end of the straight channel nozzle; the control system includes a PLC integrated control board, and the gyroscope and the servo motor are both electrically connected to the PLC integrated control board. The ratchet is an inner edge ratchet, including an outer inner edge bevel tooth surface 9b and a central circular arc surface 9a. The circular arc surface is fixedly provided with a blocking block 11 meshing with the inner edge bevel tooth surface by a large pin 10, and the circular arc surface is fixedly provided with an elastic sheet 12 meshing with the inner edge bevel tooth surface by a small pin 13. The bottom of the inner edge bevel tooth surface is movably connected to the circular arc surface, and the circular arc surface is fixedly connected to the outer wall of the radial nozzle. This arrangement can drive the circular arc surface to rotate when the radial nozzle rotates, and the blocking block and the elastic sheet can prevent the radial nozzle from reversing. The center of the Laval nozzle is the contraction section 16, the throat 17 and the expansion section 18 in sequence, and the outlet of the expansion section is connected to the straight channel in the center of the elastic block.

[0034] A method for adjusting a device capable of realizing adaptive adjustment of a coal seam hole expansion angle comprises the following steps:

[0035] S1. Before expanding the coal seam, first fix the pipeline and make the drill drill to the coal seam position;

[0036] S2. Place the resin ball into the inner hole of the drill pipe and re-thread the air braid to the drill pipe;

[0037] S3. Adjust the air compressor to 0.5MPa, open the valve on the air braid, and count for 1-2 minutes according to the drilling depth, waiting for the resin balls to be transported to the gas inlet end of the center flow channel of the reamer and block the center flow channel.

[0038] S4. Adjust the air compressor to the required working pressure, and the gas enters through the straight channel nozzles on both sides of the reamer inlet end;

[0039] S5. The angle adaptive adjustment device drives the Laval nozzle to rotate by meshing with the gear installed in the ratchet radial flow channel tube to achieve angle adjustment;

[0040] S6. After passing through the straight channel nozzle, the gas enters the ratchet radial channel tube, and then is accelerated to hypersonic speed through the Laval nozzle and ejected for hole expansion.

[0041] When used specifically, first, install the reamer between the drill rod 4 and the drill bit 7, and the drill rig 5 drives the drill rod 4, the reamer 6, and the drill bit 7 to drill and expand to the coal seam 8. The resin ball 21 is disassembled and inserted into the central channel of the drill rod 4 through the connection between the air braid 3 and the drill rod. The relationship between the diameter d1 of the resin ball, the diameter d2 of the air braid 2 channel, and the diameter d3 of the drill rod channel is d3>d1>d2. The ball designed in this way can smoothly pass through the central channel of the drill rod without falling into the internal flow channel of the air braid. Turn on the air compressor to make it slightly lower than the required working pressure, open the valve 3a on the air braid 3, and after timing for 1 minute, adjust the air compressor to the required working pressure, so as to prevent the resin ball from moving rapidly under the force of the gas and causing impact and crushing. After the compressed gas passes through the air braid 3, it carries the resin ball 21 to move in the central channel of the drill rod 4 until it reaches the inlet end of the central flow channel 6b of the reamer. At this time, the resin ball 21 blocks the central flow channel because its diameter is larger than that of the central flow channel 6b; the gas is divided into two streams in the reamer 6, flowing along path one and path two respectively. Path one: the gas passes through the straight channel nozzle 6a installed on the reamer 6, then enters the radial nozzle 6f installed in the ratchet structure 6c, and finally enters the Laval nozzle 6d to accelerate to hypersonic speed and eject; path two is the same as path one and will not be repeated. The reamer nozzle angle adaptive adjustment device is coordinated by the ratchet 9 and the control system 6e; when the reaming starts, the control system senses the angle change through the built-in gyroscope and transmits the data signal to the PLC integrated control board, and the PLC integrated control board sends instructions to control the servo motor, which cooperates with the spoke gear 15 through the output end of the servo motor, and the spoke gear 15 is meshed with the internal gear 14. The inner gear 14 is installed in the radial flow channel tube with an interference fit; the outer wall of the radial flow channel tube is fixedly matched with the central circular arc surface of the ratchet 9, and the radial flow channel tube drives the blocking fast 11 to rotate when rotating. The blocking fast 11 is fixed by the large pin 10 and can only rotate around the pin. The elastic sheet cooperates with the blocking fast 11 through the small pin 13, and the engagement of the blocking fast 11 with the ratchet bevel tooth surface 9b during the rotation process can effectively prevent the radial flow channel tube from retracting and rotating. The gas outlet section of the radial flow channel tube cooperates with the Laval nozzle 6d; the servo motor drives the spoke gear 15 to move, and the spoke gear 15 engages with the inner gear 14 installed in the radial flow channel tube, and then drives the radial flow channel tube to rotate, and finally drives the Laval nozzle 6d to rotate to achieve angle adjustment; the elastic block 19 is installed in the nozzle angle adjustment range 6d, and the middle straight channel 20 cooperates with the Laval nozzle 6d to prevent the coal slag from falling into the reamer during the coal breaking and hole expansion process. The gas enters the Laval nozzle 6d, first passes through the contraction section 16, and is accelerated to the local sonic speed at the throat 17, and then continues to be accelerated to the supersonic speed in the expansion section 18 before being ejected to expand the hole.

Claims

1. A device capable of realizing adaptive adjustment of coal seam hole expansion angle, characterized in that: It includes an air compressor, a high-pressure resistant pipeline connected to the outlet of the air compressor, the outlet of the high-pressure resistant pipeline is connected to a drill pipe through an air braid, the drill pipe is controlled by a drilling rig, a reamer is provided at the end of the drill pipe, a drill bit is provided at the end of the reamer, and a resin ball is provided in the central channel of the drill pipe, and the relationship between the diameter d1 of the resin ball, the diameter d2 of the air braid channel, and the diameter d3 of the drill pipe channel is d3>d1>d2; the reamer includes a central flow channel located in the center and a straight flow channel nozzle arranged in parallel at the upper and lower parts of the central flow channel, each straight flow channel nozzle end is provided with a reaming assembly, and two symmetrical nozzles are provided outside the reamer shell, and the nozzles are connected to the straight flow channel nozzles; it also includes a control system and an angle adaptive adjustment device; The reaming assembly includes a radial nozzle connected to the straight channel nozzle and vertically movably connected, a ratchet is provided on the outer sleeve of the radial nozzle, a Laval nozzle is provided at the end of the radial nozzle and is inclined outwardly connected to the straight channel nozzle, the Laval nozzle is located in an elastic block in the reamer shell, the elastic block is located in the nozzle angle adjustment area in the reamer, and a straight channel for placing the Laval nozzle is provided in the center of the elastic block; the ratchet is an inner edge ratchet, including an outer inner edge bevel tooth surface and a central circular arc surface, and a blocking block and an elastic sheet meshing with the inner edge bevel tooth surface are fixed on the surface of the circular arc surface by large and small pins respectively, the bottom of the inner edge bevel tooth surface is movably connected to the circular arc surface, and the circular arc surface is fixedly connected to the outer wall of the radial nozzle.

2. The device capable of realizing adaptive adjustment of coal seam hole expansion angle according to claim 1, characterized in that: The angle adaptive adjustment device includes an internal gear inserted in the air inlet end of the radial nozzle and interference fit with the inner wall of the radial nozzle, a spoke gear meshing with the internal gear, the center of the spoke gear is fixedly connected to the output end of the servo motor, and also includes a gyroscope. The servo motor, gyroscope and control system are all arranged in a cylindrical protective shell, and the protective shell is inserted at the end of the straight channel nozzle.

3. The device capable of realizing adaptive adjustment of coal seam hole expansion angle according to claim 1, characterized in that: The control system comprises a PLC integrated control board, and the gyroscope and the servo motor are both electrically connected to the PLC integrated control board.

4. The device capable of realizing adaptive adjustment of coal seam hole expansion angle according to claim 2, characterized in that: The center of the Laval nozzle is composed of a contraction section, a throat and an expansion section in sequence, and the outlet of the expansion section is connected to a straight channel in the center of the elastic block.

5. The method for adjusting the device according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Before expanding the coal seam, first fix the pipeline and make the drill drill to the coal seam position; S2. Place the resin ball into the inner hole of the drill pipe and re-thread the air braid to the drill pipe; S3. Adjust the air compressor to 0.5MPa, open the valve on the air braid, and count for 1-2 minutes according to the drilling depth, waiting for the resin balls to be transported to the gas inlet end of the center flow channel of the reamer and block the center flow channel; S4. Adjust the air compressor to the required working pressure, and the gas enters through the straight channel nozzles on both sides of the reamer inlet end; S5. The angle adaptive adjustment device drives the Laval nozzle to rotate by meshing with the gear installed in the ratchet radial flow channel tube to achieve angle adjustment; S6. After passing through the straight channel nozzle, the gas enters the ratchet radial channel tube, and then is accelerated to hypersonic speed through the Laval nozzle and ejected for hole expansion.

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