A shock wave probe for green rock splitting in a coal mine underground and a working method thereof

Abstract

This application discloses a shock wave probe for detecting green fractured rock in underground coal mines and its operating method, comprising a housing, a mounting shell, a shock wave sensor, and a buffer material assembly; the mounting shell is disposed at the front end of the housing, the shock wave sensor is disposed at the center of the mounting shell, and the buffer material assembly is sleeved on the shock wave sensor, the wave impedance range of the buffer material assembly being (1.0-1.2)×10 6 kg / (m²·s). This application solves the problem in the prior art where, when capturing pulsed high-current signals through a current detection coil, a through-hole needs to be opened on the side wall of the shock wave generator, which leads to a reduction in the structural strength of the shock wave generator. The shock wave sensor is externally wrapped with a buffer material component with a wave impedance similar to that of water. Because the wave impedance of the buffer material component is similar to that of water, shock waves in water can pass through the silicone protective layer with low loss.

Description

Technical Field

[0001] This application belongs to the field of green rock-fracture technology, specifically relating to a shock wave probe for green rock-fracture in underground coal mines and its working method. Background Technology

[0002] A shock wave generator is a device that uses a high-voltage pulsed current to induce an electric explosion in a metal wire, generating a plasma arc. This arc is then used to drive the vaporization and expansion of a water medium through Joule heating, thereby forming a shock wave. This device can achieve green rock fracturing and directional fracturing in underground coal mines. Compared to traditional hydraulic fracturing or explosive fracturing technologies, the shock wave generator has advantages such as high energy controllability, good fracturing effect, and strong environmental safety.

[0003] In green rock-splitting operations in underground coal mines, shock wave generators need to perform repetitive operations. After each operation, the equipment needs to transmit a signal to the front-end load push control system 15, which then drives the push mechanism 17 to push the new load to the energy converter 16 to carry out the next round of green rock-splitting operations.

[0004] The existing method involves installing a current detection coil inside the energy converter 16 at the back end. This coil captures the pulsed high-current signal during an electrical explosion and then transmits the signal via a signal transmission line across the pushing mechanism 17 to the load pushing control system 15 at the front end of the equipment. However, this method requires creating a through hole for the signal transmission line on the side wall of the shock wave generator's housing. This not only reduces the structural strength of the housing and limits the service life of the pushing mechanism 17, but also, because the shock wave generator uses a multi-segment rotating connection structure, the presence of the through hole prevents the standardization of the components of the pushing mechanism 17. Damage to a single component can render the entire pushing mechanism 17 unusable. Furthermore, the on-site installation of the signal line not only increases the workload significantly but is also highly susceptible to breakage during installation, leading to equipment failure. Summary of the Invention

[0005] This application provides a shock wave probe for green fractured rock in underground coal mines and its working method, which solves the problem in the prior art that when capturing pulsed high current signals through a current detection coil, it is necessary to open a wire hole on the side wall of the shock wave generator, which leads to a reduction in the structural strength of the shock wave generator.

[0006] To achieve the above objectives, embodiments of the present invention provide a shock wave probe for green fractured rock in underground coal mines, comprising a housing, a mounting housing, a shock wave sensor, and a buffer material assembly;

[0007] A mounting shell is provided at the front end of the outer casing, and the shock wave sensor is disposed at the center of the mounting shell. The shock wave sensor is fitted with the buffer material assembly, and the wave impedance range of the buffer material assembly is (1.0-1.2)×10.6 kg / (m²·s).

[0008] In one possible implementation, the cushioning material component is made of silicone.

[0009] In one possible implementation, the outer shell is a cylindrical structure, and the rear end of the outer shell is provided with an external thread structure for connecting with the internal thread section at the front end of the shock wave generator. A sealing ring is provided between the rear end of the outer shell and the internal thread section.

[0010] In one possible implementation, a waterproof partition is provided in the middle of the housing, and a sealing ring is provided between the waterproof partition and the inner wall of the housing.

[0011] In one possible implementation, the buffer material assembly includes a buffer cylinder, which is a cylindrical structure with an open rear end, and the buffer cylinder is fitted onto the shock wave sensor.

[0012] In one possible implementation, the rear end of the mounting housing is threaded into the front end of the outer shell, and the front end of the mounting housing is threaded into the rear end of the guide cone. The cushioning material assembly also includes a cushioning strip; The mounting shell has multiple windows arranged around its circumference, and the buffer strip is installed at each window.

[0013] In one possible implementation, a buffer block is installed in the space between the waterproof partition and the shock wave sensor inside the housing. The buffer block abuts against the rear end of the shock wave sensor, and the signal transmission line of the shock wave sensor passes through the buffer block and the waterproof partition and is connected to the load push control system.

[0014] In one possible implementation, a protective ring is fitted around the center of the mounting housing, and the connection between the protective ring and the outer shell and the guide cone is smooth. The wave impedance range of the protective ring is ×10. 6 kg / (m²·s).

[0015] To achieve the above objectives, this invention also provides a shock wave probe testing device, applied to the aforementioned shock wave probe for green rock fissures in underground coal mines, comprising a discharge chamber, an insulator, a high-voltage electrode rod, a plug, and a metal wire; The front end of the mounting shell is threaded to the rear end of the discharge chamber. An insulator is installed on the top wall of the discharge chamber, and a high-voltage electrode rod is installed at the center of the insulator. A plug is installed on the bottom wall of the discharge chamber, and the plug and the high-voltage electrode rod are connected by a metal wire.

[0016] To achieve the above objectives, embodiments of the present invention also provide a method for operating a shock wave probe for detecting green fractured rock in underground coal mines. This method utilizes the aforementioned shock wave probe for detecting green fractured rock in underground coal mines and the aforementioned shock wave probe testing device, and includes the following steps: Install the discharge chamber at the front end of the mounting shell, fill the discharge chamber with water, immerse the metal wire in the water, and then connect the two discharge ends of the pulse power drive source to the two ends of the metal wire. The pulse power drive source is activated, and the pulse power drive source discharges to the metal wire. Under the action of high voltage current, the metal wire explodes electrically, forming a shock wave. The generated shock wave is detected by a shock wave sensor. If the shock wave sensor is working properly, the shock wave generator is placed into the working hole to carry out the shock wave operation. During the above operation, the shock wave generated by the shock wave generator and the discharge chamber passes through the buffer material assembly and acts on the shock wave sensor. The wave impedance of the buffer material assembly is similar to that of water, so that the shock wave passes through the buffer material as much as possible and is loaded onto the shock wave sensor.

[0017] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: This invention provides a shock wave probe for green fractured rock in underground coal mines and its operating method. When in use, the shock wave probe is installed at the front end of a shock wave generator. The probe identifies whether a shock wave is generated to control the load push control system. Since the shock wave sensor is directly installed at the load push control system end, there is no need for signal lines to pass through the push mechanism for signal transmission. This solves the shortcomings of the push mechanism, such as non-standardization of components, insufficient structural strength after slotting the outer shell, complex installation, and low reliability. To avoid interference with the sensor signal caused by vibration impact from collisions between the shock wave generator and the well wall during underground movement, the core of this patent lies in using a buffer material component with a wave impedance similar to that of water to encase the shock wave sensor. Because the wave impedance of the buffer material component is similar to that of water, shock waves in water can pass through the silicone protective layer with low loss. However, the impact vibration generated by the impact of the external equipment shell is significantly attenuated by the silicone due to the significantly higher wave impedance of the metal shell compared to silicone. Through this patented structure, the underwater shock wave signal and the shell impact signal can be distinguished and judged, achieving stable triggering of shock wave operations. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a shock wave probe for green cracked rock in underground coal mines, provided in an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the installation of the shock wave probe testing device provided in an embodiment of the present invention.

[0021] Figure 3 This is a cross-sectional view of the mounting shell provided in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the structure of a shock wave generator provided in an embodiment of the present invention.

[0023] Reference numerals: 1-Outer shell; 2-Mounting shell; 21-Window; 3-Shock wave sensor; 4-Buffer material assembly; 41-Buffer cylinder; 42-Buffer strip; 43-Buffer block; 5-Waterproof partition; 6-Top ring; 7-Guide cone; 8-Protective ring; 9-Discharge chamber; 10-Insulator; 11-High voltage electrode rod; 12-Plug; 13-Metal wire; 14-Sealing cover; 15-Load push control system; 16-Energy converter; 17-Pushing mechanism. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below 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.

[0025] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," 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 the embodiments of the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0026] like Figures 1 to 4 As shown in the figure, an embodiment of the present invention provides a shock wave probe for green cracked rock in underground coal mines, including a housing 1, a mounting shell 2, a shock wave sensor 3, and a buffer material assembly 4; The front end of the outer casing 1 is provided with a mounting shell 2, and the shock wave sensor 3 is disposed at the center of the mounting shell 2. The shock wave sensor 3 is fitted with the buffer material assembly 4, and the wave impedance range of the buffer material assembly 4 is (1.0-1.2)×10. 6 kg / (m²·s).

[0027] It should be noted that the shock wave sensor 3 is externally equipped with a buffer material component 4 whose wave impedance is similar to that of water. This ensures that the internal and external media are consistent when the shock wave sensor 3 is tested in water, thereby reducing the impact on the propagation of the free-field shock wave and improving the detection accuracy of the shock wave sensor 3. The shock wave sensor 3 is a KD2006A sensor manufactured by Kedong Electronics. This sensor does not require power supply and only outputs a pressure signal. When using the shock wave probe, it is installed at the front end of the shock wave generator. The shock wave probe identifies whether a shock wave is generated to control the operation of the load push control system 15. The main body of the shock wave generator in this embodiment adopts the structure disclosed in CN113882858B and CN113738334B. Since the shock wave sensor 3 is directly installed at the end of the load push control system 15, there is no need for a signal line to cross the push mechanism 17 to transmit the signal. This solves the shortcomings of the push mechanism 17, such as the inability to standardize the components, insufficient structural strength after slotting the outer shell 1, complex installation, and low reliability. To prevent vibrations from the shock wave generator colliding with the well wall during its movement downhole and interfering with the sensor signal, the core of this patent lies in the fact that the shock wave sensor 3 is wrapped with a buffer material component 4 whose impedance is similar to that of water. Because the impedance of the buffer material component 4 is similar to that of water, shock waves in water can pass through the silicone protective layer with low loss. However, the impact vibrations generated by the external equipment casing 1 are significantly attenuated by the silicone due to the significantly higher impedance of the metal casing 1 compared to the silicone. This patented structure allows for the differentiation between the underwater shock wave signal and the impact signal from the casing 1, enabling stable triggering of shock wave operations. By placing the sensor at the front end of the shock wave generator using shock wave triggering, this patent enables wireless triggering of the load push control system 15, thereby standardizing the push mechanism 17, improving trigger reliability, and reducing component assembly difficulty.

[0028] In this embodiment, the buffer material component 4 is made of silicone.

[0029] It should be noted that the silicone buffer material component 4 can improve the detection accuracy of the shock wave sensor 3 on the one hand, and protect the shock wave sensor 3 on the other hand, preventing the shock wave sensor 3 from being damaged by the shock wave.

[0030] In this embodiment, the outer shell 1 is a cylindrical structure, and the rear end of the outer shell 1 is provided with an external thread structure. The external thread structure is used to connect with the internal thread section at the front end of the shock wave generator. A sealing ring is provided between the rear end of the outer shell 1 and the internal thread section.

[0031] It should be noted that the combination of the external thread structure and the internal thread section facilitates probe disassembly, thereby simplifying maintenance. The sealing ring prevents water from entering the housing 1.

[0032] In this embodiment, a waterproof partition 5 is provided in the middle of the outer shell 1, and a sealing ring is provided between the waterproof partition 5 and the inner wall of the outer shell 1.

[0033] It should be noted that the sealing rings at various points prevent water from seeping in.

[0034] In this embodiment, a top ring 6 is provided at the rear end of the waterproof partition 5. The top ring 6 is threaded into the outer shell 1, and the top ring 6 abuts against the rear end of the waterproof partition 5.

[0035] It should be noted that the rear end of the waterproof partition 5 is provided with a circumferential platform, which abuts against the stepped hole inside the outer casing 1. The top ring 6 is used to tighten and fix the waterproof partition 5 to ensure a sealing effect. The waterproof partition 5 is provided with holes for signal lines to pass through.

[0036] In this embodiment, the buffer material assembly 4 includes a buffer cylinder 41, which is a cylindrical structure with an open rear end, and the buffer cylinder 41 is sleeved on the shock wave sensor 3.

[0037] It should be noted that the buffer cylinder 41 protects the shock wave sensor 3 without affecting its normal operation.

[0038] In this embodiment, the rear end of the mounting shell 2 is threadedly connected to the front end of the outer shell 1, and the front end of the mounting shell 2 is threadedly connected to the rear end of the guide cone 7. The cushioning material assembly 4 also includes a cushioning strip 42; The mounting shell 2 has multiple windows 21 arranged around its perimeter, and the buffer strip 42 is installed at each window 21.

[0039] It should be noted that the mounting shell 2 is used to mount the shock wave sensor 3. The multiple windows 21 of the mounting shell 2 are used to allow the shock wave to pass through and act on the shock wave sensor 3. The buffer strip 42 can reduce the influence on the propagation of the free field shock wave. The probe is mounted at the front end of the shock wave generator, and the guide cone 7 is mounted at the front end of the probe. The guide cone 7 can make the probe move more smoothly in the borehole.

[0040] In this embodiment, a buffer block 43 is installed in the space between the waterproof partition 5 and the shock wave sensor 3 inside the outer shell 1. The buffer block 43 and the rear end of the shock wave sensor 3 abut against each other. The signal transmission line of the shock wave sensor 3 passes through the buffer block 43 and the waterproof partition 5 and is connected to the load push control system 15.

[0041] It should be noted that buffer block 43 is made of silicone, and the wave impedance range of buffer block 43 is (1.0-1.2)×10. 6kg / (m²·s). The buffer block 43 and the buffer cylinder 41 completely enclose the shock wave sensor 3, thus achieving a good protective effect. The rear end of the buffer block 43 is provided with a ring platform, which abuts against the rear end of the mounting shell 2.

[0042] In this embodiment, a protective ring 8 is fitted in the middle of the mounting shell 2. The protective ring 8 smoothly transitions at the connection between itself and the outer shell 1 and the guide cone 7. The wave impedance range of the protective ring 8 is (1.0-1.2)×10. 6 kg / (m²·s).

[0043] It should be noted that the protective ring 8 is made of polyurethane rubber, whose wave impedance is very close to that of water. The rubber is used to wrap around the mounting shell 2 in all directions to provide protection.

[0044] like Figure 2 As shown, an embodiment of the present invention provides a shock wave probe testing device, including a discharge chamber 9, an insulator 10, a high-voltage electrode rod 11, a plug 12, and a metal wire 13; The front end of the mounting shell 2 is threaded to the rear end of the discharge chamber 9. An insulator 10 is installed on the top wall of the discharge chamber 9, and a high-voltage electrode rod 11 is installed at the center of the insulator 10. A plug 12 is installed on the bottom wall of the discharge chamber 9, and the plug 12 and the high-voltage electrode rod 11 are connected by a metal wire 13.

[0045] It should be noted that during operation, the end of the buffer cylinder 41 comes into contact with the water inside the discharge chamber 9. The insulator 10 is installed in a hole in the top wall of the discharge chamber 9 via a bolt assembly; the insulator 10 isolates the high-voltage electrode rod 11 from the discharge chamber 9. The plug 12 is threaded onto a hole in the bottom wall of the discharge chamber 9; the plug 12 is used to install the metal wire 13, the upper end of which abuts against the lower end of the high-voltage electrode rod 11. A sealing cap 14 is threaded onto the front end of the discharge chamber 9, with a sealing ring at its connection point. The discharge chamber 9 also has a water inlet, and a handle is located on the outer side of the sealing cap 14.

[0046] like Figures 1 to 4 As shown in the figure, the working method of a shock wave probe for detecting green fractured rock in underground coal mines provided by this invention includes the following steps: Install the discharge chamber 9 of the shock wave probe test device at the front end of the mounting shell 2, fill the discharge chamber 9 with water, immerse the metal wire 13 in the water, and then connect the two discharge ends of the pulse power drive source to the two ends of the metal wire 13. The pulse power drive source is activated, and the pulse power drive source discharges to the metal wire 13. Under the action of high voltage current, the metal wire 13 explodes and forms a shock wave. The generated shock wave is detected by shock wave sensor 3. If shock wave sensor 3 is working normally, the shock wave generator is placed into the working hole to carry out shock wave operation. During the above operation, the discharge chamber 9 is disassembled, and the shock wave generated by the shock wave generator and the discharge chamber 9 passes through the buffer material assembly 4 and acts on the shock wave sensor 3. The wave impedance of the buffer material assembly 4 is similar to that of water, so that the shock wave passes through the buffer material as much as possible and is loaded onto the shock wave sensor 3.

[0047] It should be noted that before placing the shock wave generator into the working hole to carry out shock wave operations, the shock wave sensor 3 must be tested on the ground to ensure that it can work properly and that the sensor system circuitry has not been damaged during installation.

[0048] During testing, after removing the guide cone 7, the discharge chamber 9 was connected to the front end of the mounting shell 2. The shock wave generated by the discharge chamber 9 was used to test the working status of the entire sensing system. The shock wave intensity generated by the shock wave generator during normal operation exceeded 70MPa, which far exceeded the intensity required for the sensor to identify the signal, around 5MPa. Therefore, the ground testing system used a lower intensity for testing, with the shock wave intensity generated by the discharge chamber 9 being approximately 10MPa. Through the ground system test, the ground pre-detection of the shock wave sensor 3 system can be achieved, eliminating the possibility of wiring connection errors during installation and ensuring the reliable operation of the system in the well.

[0049] In this embodiment, it will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of the equivalents of the claims be included within the present invention.

Claims

1. A shock wave probe for use in green fractured rock in underground coal mines, characterized in that: It includes an outer shell (1), a mounting shell (2), a shock wave sensor (3), and a cushioning material assembly (4); The front end of the outer shell (1) is provided with a mounting shell (2), and the shock wave sensor (3) is provided at the center of the mounting shell (2). The shock wave sensor (3) is fitted with the buffer material assembly (4), and the wave impedance range of the buffer material assembly (4) is (1.0-1.2)×10. 6 kg / (m²·s).

2. The shock wave probe for green rock fracturing in underground coal mines according to claim 1, characterized in that: The buffer material component (4) is made of silicone.

3. The shock wave probe for green rock fissures in underground coal mines according to claim 1, characterized in that: The outer shell (1) is a cylindrical structure. The rear end of the outer shell (1) is provided with an external thread structure. The external thread structure is used to connect with the internal thread section at the front end of the shock wave generator. A sealing ring is provided between the rear end of the outer shell (1) and the internal thread section.

4. The shock wave probe for green rock fissures in underground coal mines according to claim 1, characterized in that: A waterproof partition (5) is provided in the middle of the outer shell (1), and a sealing ring is provided between the waterproof partition (5) and the inner wall of the outer shell (1).

5. The shock wave probe for green rock fissures in underground coal mines according to claim 1, characterized in that: The buffer material assembly (4) includes a buffer cylinder (41), which is a cylindrical structure with an open rear end, and the buffer cylinder (41) is sleeved on the shock wave sensor (3).

6. The shock wave probe for green rock fissures in underground coal mines according to claim 1, characterized in that: The rear end of the mounting shell (2) is threadedly connected to the front end of the outer shell (1), and the front end of the mounting shell (2) is threadedly connected to the rear end of the guide cone (7). The cushioning material assembly (4) also includes a cushioning strip (42); The mounting shell (2) has a plurality of windows (21) arranged around its perimeter, and the buffer strip (42) is installed at the window (21).

7. The shock wave probe for green rock fissures in underground coal mines according to claim 4, characterized in that: A buffer block (43) is installed in the space between the waterproof partition (5) and the shock wave sensor (3) inside the housing (1). The buffer block (43) and the rear end of the shock wave sensor (3) are in contact. The signal transmission line of the shock wave sensor (3) passes through the buffer block (43) and the waterproof partition (5) and is connected to the load push control system (15).

8. The shock wave probe for green rock fissures in underground coal mines according to claim 1, characterized in that: A protective ring (8) is fitted in the middle of the mounting shell (2). The protective ring (8) smoothly transitions to the outer shell (1) and the guide cone (7). The wave impedance range of the protective ring (8) is (1.0-1.2)×10. 6 kg / (m²·s).

9. A shock wave probe testing device, characterized in that, The shock wave probe for green rock fracture in underground coal mines as described in any one of claims 1 to 8 includes a discharge chamber (9), an insulator (10), a high-voltage electrode rod (11), a plug (12), and a metal wire (13). The front end of the mounting shell (2) is threaded to the rear end of the discharge chamber (9). An insulator (10) is installed on the top wall of the discharge chamber (9). A high-voltage electrode rod (11) is installed in the center of the insulator (10). A plug (12) is installed on the bottom wall of the discharge chamber (9). The plug (12) and the high-voltage electrode rod (11) are connected by a metal wire (13).

10. A working method for a shock wave probe used in green fractured rock in underground coal mines, characterized in that, The method employs the shock wave probe for green fractured rock in underground coal mines as described in any one of claims 1 to 8, and the shock wave probe testing device as described in claim 9, comprising the following steps: Install the discharge chamber (9) at the front end of the mounting shell (2), fill the discharge chamber (9) with water, immerse the metal wire (13) in the water, and then connect the two discharge ends of the pulse power drive source to the two ends of the metal wire (13). The pulse power drive source is activated, and the pulse power drive source discharges to the metal wire (13). Under the action of high voltage current, the metal wire (13) explodes to form a shock wave. The shock wave generated is detected by the shock wave sensor (3). If the shock wave sensor (3) works normally, the discharge chamber (9) is disassembled and the shock wave generator is placed into the working hole to carry out the shock wave operation. During the above operation, the shock wave generated by the shock wave generator and the discharge chamber (9) passes through the buffer material assembly (4) and acts on the shock wave sensor (3). The wave impedance of the buffer material assembly (4) is similar to that of water, so that the shock wave passes through the buffer material as much as possible and is loaded onto the shock wave sensor (3).

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