A shale gas pipeline stress detection device and method

Abstract

The present application relates to shale gas pipeline stress detection equipment technical field, specifically relates to a kind of shale gas pipeline stress detection device and method.The outer fixed sleeve of two, the outer wall of the outer fixed sleeve is fixedly connected with several bridge plates, and the inside of the bridge plate is slidably connected with pressure structure.The present application can be directly in construction site with two outer fixed sleeve set in the outside of pipeline, when the process of pressure block to adjustment window is moved, pressure block will push force plate to move to the surface of pipeline, so as to utilize force plate to extrude the outer wall of pipeline, then the pressure that force plate applies to the surface of pipeline is shown by force column, when the pipeline is bent, force plate will slide in transition window, force plate slides and will extrude force spring, when force spring is extruded, the scale on the surface of metering plate will be displayed, so as to show the bending degree when bending, the stress of pipeline can be detected by the above-mentioned mode.

Description

Technical Field

[0001] This invention relates to the technical field of stress detection equipment for shale gas pipelines, specifically to a stress detection device and method for shale gas pipelines. Background Technology

[0002] Pipelines are subjected to high-temperature and high-pressure media during production and service, especially shale gas pipelines in mountainous areas. Due to their unavoidable location in areas prone to geological disasters, they are susceptible to surface deformation. Furthermore, the terrain they traverse has undulating terrain and significant elevation differences. These factors make shale gas pipelines in mountainous areas highly susceptible to stress concentration, directly leading to localized deformation and reduced structural strength. This can further develop into minor defects that severely reduce the lifespan of shale gas pipelines in mountainous areas, ultimately causing pipeline failure and resulting in major safety accidents.

[0003] Existing technologies require stress testing of pipelines before installation, and the current testing method is usually software testing, which involves putting various parameters into simulation software and then conducting simulation tests. However, it is difficult to use software to simulate and test pipeline stress on the construction site, and existing technologies cannot meet the on-site stress testing needs during shale gas pipeline construction. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a stress detection device and method for shale gas pipelines that is easy to use, has high detection efficiency, and can meet the on-site stress detection needs during the construction of shale gas pipelines, in order to address the shortcomings of the existing technology.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] I. A stress detection device for shale gas pipelines

[0007] This invention provides a stress detection device for shale gas pipelines, comprising: two symmetrically arranged outer fixing sleeves 1, each outer fixing sleeve 1 being composed of two semi-circular fixing sleeves connected by bolts, and thus fitted onto the outer wall of the pipeline to be tested; the outer wall of the outer fixing sleeve 1 is uniformly provided with multiple bridge plates 3 along the circumferential direction, and a pressure structure 4 is slidably inserted through the middle of the bridge plate 3 along the radial direction of the pipeline to be tested; a force measuring structure 5 is slidably inserted through the outer fixing sleeve 1 along the axial direction parallel to the pipeline to be tested; the pressure structure 4 presses the outer wall of the pipeline to be tested radially, and the force measuring structure 5 is axially parallel and tightly attached to the outer wall of the pipeline to be tested.

[0008] Preferably, the pressure structure 4 includes an inner fixing ring 2, which is fixedly connected to the bridge plate 3, and a force-applying plate 400 is slidably connected to the middle of the inner fixing ring 2. The outer wall of the force-applying plate 400 is provided with an installation groove 401 along the direction perpendicular to the axial direction of the pipe to be tested, and a force-measuring column 402 is installed inside the installation groove 401. One end of the force-measuring column 402 is connected to the bridge plate 3, and the other end is connected to the top of the inside of the installation groove 401.

[0009] Preferably, the outer wall of the force-applying plate 400 is provided with an adjustment window 403 along the axial direction parallel to the pipe to be tested, and the bottom end of the adjustment window 403 is provided with an inclined surface. The outer side of the inner fixing ring 2 is also provided with an adjustment gear ring 406, and the adjustment gear ring 406 passes through the force-applying plate 400 through the adjustment window 403. A drive motor 408 is fixedly connected to the outer wall of the inner fixing ring 2, and the output shaft of the drive motor 408 is connected to a gear 410, and the gear 410 meshes with the inner wall of the adjustment gear ring 406.

[0010] Preferably, a plurality of pressure blocks 409 are fixedly connected to the inner wall of the adjusting toothed ring 406. The pressure blocks 409 are used to push the inclined surface at the bottom of the adjusting window 403 and drive the force plate 400 to move in the direction of pressing the pipe to be tested.

[0011] Preferably, a reset rod 404 is slidably provided on the top of the force-applying plate 400, and a reset spring 405 is sleeved on the outer ring of the reset rod 404. A slider 411 is fixedly connected to one end of the reset rod 404 inside the force-applying plate 400, and the reset rod 404 is slidably connected to the adjusting gear ring 406 through the slider 411. A sliding window 407 is provided in the middle of the adjusting gear ring 406, and the slider 411 slides along the sliding window 407.

[0012] Preferably, the force measuring structure 5 includes a force measuring plate 500, the two ends of which protrude from the side walls of the two outer fixing sleeves 1 along a direction parallel to the axial direction of the pipe to be measured, and the force measuring plate 500 is slidably connected to the outer fixing sleeves 1.

[0013] Preferably, the side walls of the two outer fixing sleeves 1 are provided with transition windows, and the two ends of the force measuring plate 500 extend out from the two transition windows respectively. A plurality of auxiliary rolling balls are provided between the inner wall of the transition window and the force measuring plate 500. The force measuring plate 500 is made of elastic material.

[0014] Preferably, the force measuring plate 500 has a docking window 501 in the middle for the force applying plate 400 to pass through, and the part of the force measuring plate 500 that passes through the outer fixing sleeve 1 has a sliding port 502 in the direction parallel to the axial direction of the pipe to be measured. A measuring plate 504 is slidably inserted inside the sliding port 502, and the measuring plate 504 has scale lines.

[0015] The portion of the force measuring plate 500 that extends out of the outer fixing sleeve 1 is also fitted with a sliding plate 505 and a force measuring spring 506. The sliding plate 505 is fixedly connected to the side wall of the corresponding outer fixing sleeve 1. One end of the force measuring spring 506 is fixedly connected to the corresponding sliding plate 505, and the other end is fixedly connected to the corresponding force measuring plate 500. The sliding plate 505 is slidably connected to the corresponding force measuring plate 500.

[0016] II. A method for stress detection in shale gas pipelines

[0017] Based on the same inventive concept, this invention also provides a method for stress detection of shale gas pipelines, which, based on the shale gas pipeline stress detection device described above, mainly includes the following steps:

[0018] S1, two external fixing sleeves 1 are symmetrically fitted onto the outer wall of the pipe to be tested, so that the center of symmetry of the external fixing sleeve 1 coincides with the center of the measurement point of the pipe to be tested;

[0019] S2, turn on the drive motor 408 to drive the adjusting gear ring 406 to rotate. When the adjusting gear ring 406 rotates, it drives the pressure block 409 to push the force plate 400 inward along the radial direction of the pipe to be tested, so that the force plate 400 presses the outer wall of the pipe to be tested.

[0020] S3, read the pressure applied by the force plate 400 to the outer wall of the pipe under test through the force measuring column 402;

[0021] S4, apply a bending moment to the pipe to be tested, so that the measuring plate 500 bends along with the outer wall of the pipe to be tested;

[0022] S5, the force measuring plate 500 slides relative to the transition window and presses the connected force measuring spring 506, causing the force measuring spring 506 to move relative to the measuring plate 504;

[0023] S6. By measuring the position of the end of the force measuring spring 506 corresponding to the scale line on the measuring plate 504, the bending moment borne by the pipe under test is read.

[0024] S7. Based on the read pressure and bending moment, calculate the stress borne by the pipe under test.

[0025] Furthermore, the unit torque M0 of the scale line on the measuring plate 504 satisfies the following formula:

[0026]

[0027] In the formula, L is the total length of the bent section of the pipe to be tested, EI is the rotational stiffness of the pipe to be tested, h is the total length of the measuring plate, l is the total length of the force measuring plate, N is the total number of scale lines, and C is a correction coefficient related to the material of the pipe to be tested.

[0028] Compared with the prior art, the present invention has the following main advantages:

[0029] 1. This invention proposes a stress detection device for shale gas pipelines. Two external fixing sleeves can be directly fitted onto the outside of the pipeline at the construction site. Then, the drive motor is turned on to drive the adjusting gear ring to rotate. When the adjusting gear ring rotates, it will drive the pressure block to move together. As the pressure block moves into the adjustment window, the pressure block will push the force plate to move towards the surface of the pipeline, thereby using the force plate to squeeze the outer wall of the pipeline. As the force plate moves towards the surface of the pipeline, it will squeeze the force measuring column, so that the force measuring column displays the pressure applied by the force plate to the surface of the pipeline.

[0030] 3. When using this invention, the force measuring plate will slide within the transition window when the pipe is bent. When the force measuring plate slides, it will squeeze the force measuring spring. When the force measuring spring is squeezed, the scale on the surface of the measuring plate will be displayed, thus showing the bending force during bending. The stress of the pipe can be detected in the above way.

[0031] 4. This invention proposes a stress detection method for shale gas pipelines. By directly reading the pressure and bending moment borne by the outer wall of the pipeline under test through a force measuring column and a measuring plate, the stress borne by the pipeline under test can be calculated. This method can achieve efficient and rapid pipeline stress detection, and the measurement steps do not require the use of additional software systems, which can meet the on-site stress detection needs during shale gas pipeline construction. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of a shale gas pipeline stress detection device according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram showing the disassembled stress detection device for a shale gas pipeline according to an embodiment of the present invention;

[0034] Figure 3 This is a cross-sectional view of a shale gas pipeline stress detection device according to an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of the connection between the bridge plate and the pressure structure in an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of the force measuring structure in an embodiment of the present invention;

[0037] Figure 6 This is a schematic diagram showing the connection between the reset rod and the adjusting gear ring in an embodiment of the present invention;

[0038] Figure 7 This is a schematic diagram illustrating the use of a shale gas pipeline stress detection device in an embodiment of the present invention;

[0039] Figure 8This is a flowchart of a shale gas pipeline stress detection method according to an embodiment of the present invention.

[0040] In the diagram: 1. Outer fixing sleeve; 2. Inner fixing ring; 3. Bridge plate; 4. Pressure structure; 5. Force measuring structure; 6. Connecting ear; 400. Force application plate; 401. Mounting groove; 402. Force measuring column; 403. Adjustment window; 404. Reset rod; 405. Reset spring; 406. Adjustment gear ring; 407. Sliding window; 408. Drive motor; 409. Pressure block; 410. Gear; 411. Slider; 500. Force measuring plate; 501. Docking window; 502. Sliding port; 503. Protective cover; 504. Measuring plate; 505. Slide plate; 506. Force measuring spring. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0042] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0043] Example 1: This example provides a stress detection device for shale gas pipelines, such as... Figures 1-6 As shown, it mainly includes two outer fixing sleeves 1. Connecting ears 6 are symmetrically fixedly connected to the outer walls of the two outer fixing sleeves 1, and the connecting ears 6 on the outer walls of the two outer fixing sleeves 1 are connected by bolts. Several bridge plates 3 are fixedly connected to the outer walls of the outer fixing sleeves 1, and pressure structures 4 are slidably connected inside the bridge plates 3. The pressure structure 4 can be used to pressurize and test the pipes inside the outer fixing sleeves 1. Force measuring structures 5 are also provided inside the bridge plates 3.

[0044] The pressure structure 4 includes two inner fixing rings 2, both of which are semi-circular. Connecting ears 6 are also fixedly connected to the outer walls of the two inner fixing rings 2, and the connecting ears 6 on the outer walls of the two inner fixing rings 2 are also connected by bolts. The inner fixing rings 2 are fixedly connected to the bridge plate 3, and a force-applying plate 400 is slidably connected inside the inner fixing rings 2. A rectangular window is opened on the outer wall of the bridge plate 3, and the force-applying plate 400 passes through the bridge plate 3 through the rectangular window. The outer wall of the force-applying plate 400 is symmetrically provided with mounting grooves 401, and a force-measuring column 402 is installed inside each mounting groove 401. One end of the force-measuring column 402 is fixedly connected to the bridge plate 3, and the other end is fixedly connected to the top of the inside of the mounting groove 401.

[0045] An adjustment window 403 is provided on the outer wall of the force-applying plate 400. The adjustment window 403 is located between two mounting slots 401, and the bottom of the inner end of the adjustment window 403 is provided with an inclined surface. An adjustment gear ring 406 is also provided on the outside of the inner fixing ring 2. The teeth of the adjustment gear ring 406 are located on the inner wall of the adjustment gear ring 406, and the adjustment gear ring 406 passes through the force-applying plate 400 through the adjustment window 403. A drive motor 408 is fixedly connected to the outer wall of the inner fixing ring 2. A gear 410 is fixedly connected to the output shaft, and the gear 410 meshes with the inner wall of the adjusting gear ring 406. Specifically, the adjusting gear ring 406 includes two semi-circular gear rings that can be interlocked with each other, and the two semi-circular gear rings are slidably connected to the inner fixed ring 2 respectively. Several pressure blocks 409 are also fixedly connected to the inner wall of the adjusting gear ring 406. The pressure block 409 and the inclined surface at the bottom of the adjusting window 403 can push the force plate 400 into the inner fixed ring 2.

[0046] A reset rod 404 is slidably connected inside the force-applying plate 400. A reset spring 405 is sleeved on the outside of the reset rod 404. A slider 411 is fixedly connected to one end of the reset rod 404 located on the force-applying plate 400. The reset rod 404 is slidably connected to the adjusting gear ring 406 through the slider 411. A sliding window 407 is opened on the outer wall of the adjusting gear ring 406, and the slider 411 is located in the sliding window 407. When the pressure block 409 pushes the force-applying plate 400 downward, the reset rod 404 will compress the reset spring 405. After the pressure block 409 is reset, the force-applying plate 400 will be reset under the action of the reset spring 405.

[0047] The force measuring structure 5 includes a force measuring plate 500. The force measuring plate 500 is elastic and can be made of stainless steel. A docking window 501 is provided in the middle of the force measuring plate 500, and the force applying plate 400 passes through the docking window 501 through the force measuring plate 500. Both ends of the force measuring plate 500 pass through the outer wall of the outer fixing sleeve 1, and the force measuring plate 500 is slidably connected to the outer fixing sleeve 1. A transition window is provided on the outer wall of the outer fixing sleeve 1, and the force measuring plate 500 passes through the outer wall of the outer fixing sleeve 1 through the transition window. Several auxiliary balls are rotatably connected inside the transition window to facilitate the sliding of the force measuring plate 500 within the transition window. A protective cover 503, which is a corrugated flexible hose, is fitted over the portion of the force measuring plate 500 that penetrates the outer fixing sleeve 1. A sliding plate 505 is also fitted over the portion of the force measuring plate 500 that penetrates the outer fixing sleeve 1. The sliding plate 505 is fixedly connected to the outer fixing sleeve 1 and is slidably connected to the force measuring plate 500. A force measuring spring 506 is fixedly connected to the outside of the sliding plate 505 and is also fitted over the outside of the force measuring plate 500. A sliding opening 502 is also provided inside the force measuring plate 500, and a measuring plate 504 is slidably connected inside the sliding opening 502. The measuring plate 504 is slidably connected to the force measuring plate 500, and a scale is engraved on the outer wall of the measuring plate 504.

[0048] The working principle of this invention is:

[0049] like Figure 7 As shown, in use, the two outer fixing sleeves 1 are fitted onto the outside of the pipe. Then, the drive motor 408 is turned on to drive the adjusting gear ring 406 to rotate. When the adjusting gear ring 406 rotates, it will drive the pressure block 409 to move together. During the process of the pressure block 409 moving into the adjusting window 403, the pressure block 409 will push the force plate 400 to move towards the surface of the pipe, thereby using the force plate 400 to squeeze the outer wall of the pipe. During the process of the force plate 400 moving towards the surface of the pipe, the force plate 400 will squeeze the force measuring column 402, thereby making the force measuring column 402 display the pressure applied by the force plate 400 to the surface of the pipe.

[0050] When the pipe is bent, the force measuring plate 500 slides within the transition window. As the force measuring plate 500 slides, it compresses the force measuring spring 506. When the force measuring spring 506 is compressed, the scale on the surface of the measuring plate 504 is displayed, thus showing the bending force during the bend. The stress of the pipe can be detected in this way.

[0051] Example 2: This example provides a shale gas pipeline stress detection device, which includes two outer fixing sleeves 1. The outer fixing sleeve 1 is characterized in that a plurality of bridge plates 3 are fixedly connected to the outer wall of the outer fixing sleeve 1, and a pressure structure 4 is slidably connected inside the bridge plate 3. The pressure structure 4 can be used to pressurize and detect the pipeline inside the outer fixing sleeve 1. The bridge plate 3 is also provided with a force measuring structure 5 inside.

[0052] Furthermore, the pressure structure 4 includes two inner fixing rings 2, which are fixedly connected to the bridge plate 3. A force-applying plate 400 is slidably connected inside the inner fixing ring 2. The outer wall of the force-applying plate 400 is symmetrically provided with mounting grooves 401, and a force-measuring column 402 is installed inside each mounting groove 401. One end of the force-measuring column 402 is fixedly connected to the bridge plate 3, and the other end is fixedly connected to the top of the inside of the mounting groove 401.

[0053] Furthermore, an adjustment window 403 is provided on the outer wall of the force-applying plate 400, and the bottom of the inner end of the adjustment window 403 is provided with an inclined surface. An adjustment gear ring 406 is also provided on the outside of the inner fixing ring 2, and the adjustment gear ring 406 passes through the force-applying plate 400 through the adjustment window 403. A drive motor 408 is fixedly connected to the outer wall of the inner fixing ring 2, and a gear 410 is fixedly connected to the output shaft of the drive motor 408, and the gear 410 meshes with the inner wall of the adjustment gear ring 406.

[0054] Furthermore, several pressure blocks 409 are fixedly connected to the inner wall of the adjusting toothed ring 406. The force plate 400 can be pushed into the inner fixed ring 2 by the pressure blocks 409 and the inclined surface at the bottom of the adjusting window 403.

[0055] Furthermore, a reset rod 404 is slidably connected inside the force-applying plate 400, and a reset spring 405 is sleeved on the outside of the reset rod 404. A slider 411 is fixedly connected to one end of the reset rod 404 located on the force-applying plate 400, and the reset rod 404 is slidably connected to the adjusting gear ring 406 through the slider 411. A sliding window 407 is opened on the outer wall of the adjusting gear ring 406, and the slider 411 is located in the sliding window 407.

[0056] Furthermore, the force measuring structure 5 includes a force measuring plate 500, both ends of which pass through the outer wall of the outer fixing sleeve 1, and the force measuring plate 500 is slidably connected to the outer fixing sleeve 1.

[0057] Furthermore, a sliding plate 505 is fitted onto one end of the force measuring plate 500 that passes through the outer fixing sleeve 1. The sliding plate 505 is fixedly connected to the outer fixing sleeve 1. A force measuring spring 506 is fixedly connected to the outside of the sliding plate 505. A sliding opening 502 is also provided inside the force measuring plate 500. A measuring plate 504 is slidably connected inside the sliding opening 502. Scales are engraved on the outer wall of the measuring plate 504.

[0058] Example 3: Based on the same inventive concept, this example also provides a method for stress detection of shale gas pipelines, based on the shale gas pipeline stress detection device described above, such as... Figure 8As shown, the main steps include the following:

[0059] S1, two external fixing sleeves 1 are symmetrically fitted onto the outer wall of the pipe to be tested, so that the center of symmetry of the external fixing sleeve 1 coincides with the center of the measurement point of the pipe to be tested;

[0060] S2, turn on the drive motor 408 to drive the adjusting gear ring 406 to rotate. When the adjusting gear ring 406 rotates, it drives the pressure block 409 to push the force plate 400 inward along the radial direction of the pipe to be tested, so that the force plate 400 presses the outer wall of the pipe to be tested.

[0061] S3, read the pressure applied by the force plate 400 to the outer wall of the pipe under test through the force measuring column 402;

[0062] S4, apply a bending moment to the pipe to be tested, so that the measuring plate 500 bends along with the outer wall of the pipe to be tested;

[0063] S5, the force measuring plate 500 slides relative to the transition window and presses the connected force measuring spring 506, causing the force measuring spring 506 to move relative to the measuring plate 504;

[0064] S6. By measuring the position of the end of the force measuring spring 506 corresponding to the scale line on the measuring plate 504, the bending moment borne by the pipe under test is read.

[0065] S7. Based on the read pressure and bending moment, calculate the stress borne by the pipe under test.

[0066] Furthermore, the unit torque M0 of the scale line on the measuring plate 504 satisfies the following formula:

[0067]

[0068] In the formula, L is the total length of the bent section of the pipe to be tested, EI is the rotational stiffness of the pipe to be tested, h is the total length of the measuring plate, l is the total length of the force measuring plate, N is the total number of scale lines, and C is a correction coefficient related to the material of the pipe to be tested.

[0069] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0070] In summary:

[0071] 1. This invention proposes a stress detection device for shale gas pipelines. Two external fixing sleeves can be directly fitted onto the outside of the pipeline at the construction site. Then, the drive motor is turned on to drive the adjusting gear ring to rotate. When the adjusting gear ring rotates, it will drive the pressure block to move together. As the pressure block moves into the adjustment window, the pressure block will push the force plate to move towards the surface of the pipeline, thereby using the force plate to squeeze the outer wall of the pipeline. As the force plate moves towards the surface of the pipeline, it will squeeze the force measuring column, so that the force measuring column displays the pressure applied by the force plate to the surface of the pipeline.

[0072] 3. When using this invention, the force measuring plate will slide within the transition window when the pipe is bent. When the force measuring plate slides, it will squeeze the force measuring spring. When the force measuring spring is squeezed, the scale on the surface of the measuring plate will be displayed, thus showing the bending force during bending. The stress of the pipe can be detected in the above way.

[0073] 4. This invention proposes a stress detection method for shale gas pipelines. By directly reading the pressure and bending moment borne by the outer wall of the pipeline under test through a force measuring column and a measuring plate, the stress borne by the pipeline under test can be calculated. This method can achieve efficient and rapid pipeline stress detection, and the measurement steps do not require the use of additional software systems, which can meet the on-site stress detection needs during shale gas pipeline construction.

[0074] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A stress detection device for shale gas pipelines, sleeved on the outer wall of the pipeline to be tested, characterized in that: It includes two symmetrically arranged outer fixing sleeves (1), and the outer fixing sleeve (1) is composed of two semi-circular fixing sleeves connected by bolts, and is then fitted onto the outer wall of the pipe to be tested. The outer wall of the outer fixing sleeve (1) is uniformly provided with multiple bridge plates (3) along the circumference, and the middle part of the bridge plate (3) is slidably provided with a pressure structure (4) along the radial direction of the pipe to be tested. The outer fixing sleeve (1) is slidably provided with a force measuring structure (5) along the axial direction parallel to the pipe to be tested. The pressure structure (4) presses the outer wall of the pipe to be tested radially, and the force measuring structure (5) is axially parallel and tightly attached to the outer wall of the pipe to be tested. The pressure structure (4) includes an inner fixing ring (2), which is fixedly connected to the bridge plate (3). A force-applying plate (400) is slidably connected to the middle of the inner fixing ring (2). An installation groove (401) is provided on the outer wall of the force-applying plate (400) along the direction perpendicular to the axial direction of the pipe to be tested. A force-measuring column (402) is installed inside the installation groove (401). One end of the force-measuring column (402) is connected to the bridge plate (3), and the other end is connected to the top of the inside of the installation groove (401). An adjustment window (403) is provided on the outer wall of the force-applying plate (400) along the direction parallel to the axial direction of the pipe to be tested, and an inclined surface is provided at the bottom of the adjustment window (403). An adjustment gear ring (406) is also provided on the outside of the inner fixing ring (2), and the adjustment gear ring (406) passes through the force-applying plate (400) through the adjustment window (403). A drive motor (408) is fixedly connected to the outer wall of the inner fixing ring (2), and a gear (410) is connected to the output shaft of the drive motor (408), and the gear (410) meshes with the inner wall of the adjustment gear ring (406). Multiple pressure blocks (409) are fixedly connected to the inner wall of the adjusting toothed ring (406). The pressure blocks (409) are used to push the inclined surface at the bottom of the adjusting window (403) and drive the force plate (400) to move in the direction of pressing the pipe to be tested. A reset rod (404) is slidably inserted through the top of the force-applying plate (400). A reset spring (405) is sleeved on the outer ring of the reset rod (404). A slider (411) is fixedly connected to one end of the reset rod (404) inside the force-applying plate (400). The reset rod (404) is slidably connected to the adjusting gear ring (406) through the slider (411). A sliding window (407) is opened in the middle of the adjusting gear ring (406), and the slider (411) slides along the sliding window (407).

2. The shale gas pipeline stress detection device according to claim 1, characterized in that, The force measuring structure (5) includes a force measuring plate (500). The two ends of the force measuring plate (500) extend out from the side walls of the two outer fixed sleeves (1) in a direction parallel to the axial direction of the pipe to be measured, and the force measuring plate (500) is slidably connected to the outer fixed sleeves (1).

3. The shale gas pipeline stress detection device according to claim 2, characterized in that, The two outer fixing sleeves (1) are provided with transition windows on their side walls. The two ends of the force measuring plate (500) pass through the two transition windows respectively, and multiple auxiliary rolling balls are provided between the inner wall of the transition window and the force measuring plate (500). The force measuring plate (500) is made of elastic material.

4. A shale gas pipeline stress detection device according to claim 2, characterized in that, The force measuring plate (500) has a docking window (501) in the middle for the force applying plate (400) to pass through. The part of the force measuring plate (500) that passes through the outer fixing sleeve (1) has a sliding port (502) in a direction parallel to the axial direction of the pipe to be measured. A measuring plate (504) slides through the sliding port (502), and the measuring plate (504) has scale lines. The portion of the force measuring plate (500) that extends out of the outer fixing sleeve (1) is also fitted with a sliding plate (505) and a force measuring spring (506). The sliding plate (505) is fixedly connected to the side wall of the corresponding outer fixing sleeve (1). One end of the force measuring spring (506) is fixedly connected to the corresponding sliding plate (505), and the other end is fixedly connected to the corresponding force measuring plate (500). The sliding plate (505) is slidably connected to the corresponding force measuring plate (500).

5. A method for stress detection in shale gas pipelines, based on the shale gas pipeline stress detection device according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1, two external fixing sleeves (1) are symmetrically fitted on the outer wall of the pipe to be tested, so that the center of symmetry of the external fixing sleeve (1) coincides with the center of the measurement point of the pipe to be tested; S2, turn on the drive motor (408) to drive the adjusting gear ring (406) to rotate. When the adjusting gear ring (406) rotates, it drives the pressure block (409) to push the force plate (400) inward along the radial direction of the pipe to be tested, so that the force plate (400) presses the outer wall of the pipe to be tested. S3, read the pressure applied by the force plate (400) to the outer wall of the pipe to be tested through the force measuring column (402); S4, apply a bending moment to the pipe to be tested, so that the measuring plate (500) bends together with the outer wall of the pipe to be tested; S5, the force measuring plate (500) slides relative to the transition window and presses the connected force measuring spring (506), causing the force measuring spring (506) to move relative to the measuring plate (504); S6, by measuring the position of the end of the force measuring spring (506) corresponding to the scale line on the measuring plate (504), the bending moment borne by the pipe to be measured is read; S7. Based on the read pressure and bending moment, calculate the stress borne by the pipe under test.

6. The method for stress detection in shale gas pipelines according to claim 5, characterized in that, The unit torque M0 of the scale line on the measuring plate (504) satisfies the following formula: In the formula, L is the total length of the curved section of the pipe to be tested, EI is the rotational stiffness of the pipe to be tested, h is the total length of the measuring plate, l is the total length of the force measuring plate, and N is the total number of scale lines.

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