A device for detecting the tensile yield strength of an inner liner of a petroleum pipeline

Abstract

This invention relates to the field of tensile testing technology, and more particularly to a device for testing the tensile yield strength of lined oil pipelines. The device includes a testing platform, a testing frame, an outer pipe, and an inner pipe. The testing frame is fixedly connected to the top of the testing platform. A movable seat that can move up and down is provided on the inner side of the testing frame. A fixed seat is fixedly connected to the top of the testing platform relative to the inner side of the testing frame. This invention, through the setting of an outer clamp and an inner support mechanism, and by adopting a separate inner and outer layer production process during the research and development stage of metal-lined oil pipelines, ensures that the lining and the steel pipe are not adhered to each other. During testing, the outer pipe is directly clamped by the outer clamp, and the inner pipe is independently supported by the inner support mechanism. Subsequently, the upper and lower hydraulic telescopic cylinders are controlled to stretch synchronously, and the upper and lower tension sensors are used for separate monitoring. This allows for the simultaneous acquisition of the yield strength, elastic modulus, and deformation characteristics of both the steel pipe and the metal lining, truly reflecting the independent mechanical behavior of the two metal materials.

Description

Technical Field

[0001] This invention relates to the field of tensile testing technology, and in particular to a device for testing the tensile yield strength of lined oil pipelines. Background Technology

[0002] Lined oil pipelines are composite pipelines with a layer of corrosion-resistant or wear-resistant material on the inner wall of a steel pipe. They are widely used for transporting oil, natural gas, and chemical media. As the oil and gas field extraction environment becomes increasingly complex, the corrosion of pipelines by media with high sulfur content, high carbon dioxide content, and high mineralization intensifies. Therefore, it is necessary to develop new lining materials, such as polyolefin materials resistant to hydrogen sulfide corrosion, fluoroplastics resistant to high temperature and high pressure, and intelligent coating materials with self-healing functions, to improve the service life and safety of pipelines under extreme working conditions. During the development of new materials, it is necessary to test the tensile yield strength of the composite material with the steel pipe to verify whether the mechanical properties of the material meet the requirements of engineering applications.

[0003] The tensile yield strength testing device mainly consists of a clamping system, a loading system, a force sensor, a displacement measurement system, and a data acquisition system. During testing, the standard pipe section sample is first clamped in the clamps at both ends and zeroed. Then, a tensile load is applied uniformly at a set rate, and force and displacement data are collected simultaneously. The system automatically determines the yield point based on the stress-strain curve and outputs mechanical performance indicators such as yield strength, tensile strength, and elongation, thereby completing the quantitative evaluation of the tensile yield strength of the lined oil pipeline.

[0004] Existing tensile testing devices for lined oil pipelines can only perform a single tensile test on the entire composite pipe, and cannot test the lining and steel pipe separately. In the research and development stage of new materials, researchers need to obtain the yield strength of the steel pipe and the lining separately to optimize material matching. However, the existing devices lack the functions of independent clamping and synchronous monitoring, and can only separate the lining and the steel pipe before testing them separately. This process is cumbersome and the sample preparation cycle is long, which seriously restricts the research and development efficiency of new materials for lined oil pipelines.

[0005] Therefore, a device for testing the tensile yield strength of lined oil pipelines is proposed to solve the above problems. Summary of the Invention

[0006] To address the existing technical problem that the lining and steel pipe cannot be simultaneously and independently subjected to tensile testing, this invention provides a device for testing the tensile yield strength of lined oil pipelines.

[0007] The technical solutions provided by the embodiments of the present invention are as follows: This invention provides a tensile yield strength testing device for lined oil pipelines, comprising a testing platform, a testing frame, an outer pipe, and an inner pipe. The testing frame is fixedly connected to the top of the testing platform. A movable seat that can move up and down is provided on the inner side of the testing frame. A fixed seat is fixedly connected to the top of the testing platform relative to the inner side of the testing frame. Both the movable seat and the fixed seat are provided with an upper plate. A lower plate is provided on the side of the upper plate that is away from each other. An external clamp for holding the outer pipe is provided on the side of the fixed seat and the movable seat that is close to each other. The side of the upper plate that is close to each other is respectively provided through the outer wall of the movable seat and the fixed seat. A pull-down force sensor is fixedly connected to each of the upper plates on the side closest to each other. The sensing end of the pull-down force sensor is fixedly connected to the outer wall of the outer clamp. A cylinder is provided through the inner side of the outer clamp. The top of the cylinder is provided through the top of the upper plate. The cylinder is fixedly connected through the inside of the lower plate. An upper pull-down force sensor is fixedly connected to each of the two lower plates on the side furthest from each other. The sensing end of the upper pull-down force sensor is fixedly connected to an upper electromagnet. The cylinder is made of iron. The side end of the cylinder is adsorbed and fixed to the upper electromagnet. The cylinder is provided with an internal support mechanism for clamping the inner tube. An upper hydraulic telescopic cylinder is fixedly connected to the middle of the top of the movable seat. A pair of lower hydraulic telescopic cylinders are fixedly connected to both sides of the top of the movable seat. The output end of the upper hydraulic telescopic cylinder passes through the movable seat and is fixedly connected to the top of the upper tension sensor. The output end of the lower hydraulic telescopic cylinder passes through the movable seat and the lower plate and is fixedly connected to the top of the upper plate. One of the upper plates and one of the lower plates are longitudinally slidably connected to the inside of the movable seat. One of the upper plates and one of the lower plates are fixedly connected to the inside of the fixed seat.

[0008] In the above technical solution, further, the internal support mechanism includes a central hydraulic telescopic cylinder, an internal support block, and a fixed cylinder. The fixed cylinder is fixedly connected to the side of the cylinder closest to each other. Two pairs of internal support blocks are provided, each pair of which is laterally slidably connected to both sides of the fixed cylinder. Side plates are provided on both the front and rear sides of the fixed cylinder. The side plates are fixedly connected to the side walls of the internal support blocks on both sides. An upper rod is fixedly connected to the side of each side plate closest to each other. A pressing block is fixedly connected between the side plates. The pressing block is inclined on both sides. The central hydraulic telescopic cylinder is fixedly connected to the sensing end of the upper tension sensor. The output end of the central hydraulic telescopic cylinder passes through the cylinder and is fixedly connected to a pull rod. The pull rod is fixedly connected to the side wall of the pressing block. Each side plate is equipped with a fixing plate on the side away from the inner support block. Three upper springs are fixedly connected between the fixing plate and the side plate. The fixing plate is fixedly connected to the inside of the fixing cylinder. The outer tube is directly clamped by the outer clamp, and the inner tube is independently supported by the inner support mechanism. Then, the upper and lower hydraulic telescopic cylinders are controlled to operate synchronously to implement tensile loading. The upper and lower tension sensors are used to independently collect load data. The yield strength, elastic modulus and deformation characteristics of the steel pipe and the metal lining can be obtained simultaneously at one time. The independent mechanical response of the two metal materials in the composite state is truly restored. This provides an accurate basis for the selection of inner and outer layer materials, wall thickness matching and interface optimization design, and significantly improves the integrity and reliability of material performance evaluation in the research and development stage.

[0009] In the above technical solution, a lower frame is provided below the upper fixed cylinder, and a T-shaped block is fixedly connected to the bottom end of the upper extrusion block. The T-shaped block is set through the bottom end of the lower frame. Several lower springs are fixedly connected between the outer wall of the T-shaped block and the bottom of the lower frame. Both outer walls of the two cylinders are provided with flared rings. A pair of support frames are fixedly connected to the inner side of the flared rings. Top blocks are fixedly connected to the top of the outer walls of the two pull rods. The top blocks abut against the bottom end of the support frames. Vertical grooves are opened on both sides of the outer wall of the cylinder. The support frames are longitudinally slidably connected to the inner side of the vertical grooves. Top springs are fixedly connected between the side wall of the support frames and the inner side of the vertical grooves. Electromagnetic rings are fixedly connected through the fixed cylinder on the side near the cylinder. The flared rings are made of iron.

[0010] In the above technical solution, further, a number of right-angled blocks with inclined surfaces are fixedly connected at equal intervals at the bottom end of the upper fixed cylinder, and a number of top grooves are opened at equal intervals at the top end of the lower frame. The number of right-angled blocks are inserted into the inner side of the corresponding top groove. Side frames are slidably connected horizontally through the outer wall of the lower frame relative to the position next to the top groove. A lower rod is fixedly connected to the inner side of the side frame. A baffle is provided on the inner side of the side frame. The baffle is fixedly connected to the inner side of the top groove. A bottom spring is fixedly connected between the side wall of the baffle and the inner side of the side frame.

[0011] In the above technical solution, furthermore, lower electromagnets are fixedly connected to both the front and rear sides of the upper plate, and the lower electromagnets are set between the upper plate and the lower plate. The outer wall of the lower plate is made of iron. Through the above structure, the inner support mechanism can quickly switch to the flaring yield detection mode. During the detection, the inner tube moves down to expose the top of the outer tube. The lower outer clamp restricts the displacement of the outer tube. The two fixed cylinders are converted into flaring rings by the middle hydraulic telescopic cylinder. The upper flaring ring is pressed against the inner wall of the outer tube, and the lower flaring ring is pressed against the inner wall of the inner tube. At the same time, the side frame on the lower frame extends and presses against the top of the inner tube. Then, the upper hydraulic telescopic cylinder drives the middle hydraulic telescopic cylinder and the side frame to move down to squeeze the inner tube. The lower flaring ring performs flaring forming on the bottom outer wall of the inner tube. At the same time, the lower hydraulic telescopic cylinder drives the cylinder and the flaring ring above it to move down to perform flaring forming on the top of the outer tube, realizing the synchronous flaring detection of the steel pipe and the metal lining and their independent monitoring.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention, through the setting of external clamps and internal support mechanisms, and by adopting a separate production process for inner and outer layers during the research and development stage of metal-lined oil pipelines, ensures that the lining and steel pipe are not adhered to each other. During testing, the outer pipe is directly clamped by the external clamps, and the inner pipe is independently supported by the internal support mechanism. Subsequently, the upper and lower hydraulic telescopic cylinders are controlled to stretch synchronously, and the upper and lower tension sensors are monitored separately. This allows for the simultaneous acquisition of the yield strength, elastic modulus, and deformation characteristics of the steel pipe and the metal lining, accurately reflecting the independent mechanical behavior of the two metal materials. This provides precise data support for optimizing the selection of inner and outer layer materials and wall thickness matching, significantly improving research and development efficiency and testing reliability.

[0013] 2. This invention, through the design of structures such as flaring rings and lower frames, enables the internal support mechanism to quickly adjust to the flaring yield detection mode. During detection, the inner tube moves downward, exposing the top of the outer tube. The lower outer clamp restricts the displacement of the outer tube. The two fixed cylinders are converted into flaring rings by a central hydraulic telescopic cylinder. The upper flaring ring abuts against the inner wall of the outer tube, and the lower flaring ring abuts against the inner wall of the inner tube. At the same time, the side frame on the lower frame extends and abuts against the top of the inner tube. Then, the upper hydraulic telescopic cylinder can be controlled to drive the central hydraulic telescopic cylinder and the side frame to move downward, squeezing the inner tube. The lower flaring ring flares the outer wall of the bottom end of the inner tube. Simultaneously, the lower hydraulic telescopic cylinder drives the cylinder and the upper flaring ring to move downward, flaring the top of the outer tube. This achieves synchronous flaring detection of the steel pipe and the metal lining, with each being monitored independently. Attached Figure Description

[0014] Figure 1 This is a front perspective view of the tensile yield strength testing device of the present invention. Figure 2 This is a frontal three-dimensional structural diagram of the tensile yield strength testing device of the present invention during flared testing. Figure 3 For the appendix Figure 2 A magnified view of the structure at point A in the middle; Figure 4 This is a schematic diagram of a partial cross-section of the outer tube and inner tube during the flaring test of the present invention. Figure 5 This is a front perspective view of the movable base, fixed base, and test platform of the present invention. Figure 6 This is a frontal perspective structural diagram of the upper hydraulic telescopic cylinder, lower hydraulic telescopic cylinder, upper plate, lower plate, and outer clamp of the present invention. Figure 7 This is a partial cross-sectional three-dimensional structural diagram of the upper hydraulic telescopic cylinder, lower hydraulic telescopic cylinder, upper plate, lower plate and outer clamp of the present invention; Figure 8 This is a partial cross-sectional three-dimensional structural diagram of the cylinder, flared ring, fixing cylinder and lower frame of the present invention. Figure 9 This is a bottom-view perspective view of the flared ring and support frame of the present invention. Figure 10 This is a partial cross-sectional three-dimensional structural diagram of the fixed cylinder, the central hydraulic telescopic cylinder, and the inner support block of the present invention. Figure 11 This is a partial cross-sectional perspective view of the lower frame and T-block of the present invention. Figure 12 This is a top-view schematic diagram of the three-dimensional structure of the side frame and right-angle block of the present invention.

[0015] In the diagram: 1. Test platform; 2. Test frame; 3. Movable seat; 4. Fixed seat; 5. Upper plate; 6. Lower plate; 7. External clamp; 8. Outer tube; 9. Inner tube; 10. Cylinder; 11. Upper tension sensor; 12. Upper hydraulic telescopic cylinder; 13. Lower hydraulic telescopic cylinder; 14. Lower tension sensor; 15. Middle hydraulic telescopic cylinder; 16. Inner support block; 17. Fixed cylinder; 18. Side plate; 19. Upper rod; 20. 21. Extrusion block; 22. Pull rod; 23. Fixing plate; 24. Upper spring; 25. Lower frame; 26. T-block; 27. Lower spring; 28. Flaring ring; 29. ​​Support frame; 30. Top block; 31. Vertical groove; 32. Electromagnetic ring; 33. Right-angle block; 34. Top groove; 35. Upper electromagnet; 36. Side frame; 37. Lower rod; 38. Baffle; 39. Bottom spring; 40. Lower electromagnet; 51. Top spring. Detailed Implementation

[0016] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the invention is not limited to the specific embodiments disclosed below.

[0018] In practical use, it was found that the existing tensile testing device for lined oil pipelines can only perform a single tensile test on the composite pipe as a whole, and cannot test the lining and steel pipe separately. In the research and development stage of new materials, researchers need to obtain the yield strength of the steel pipe and the lining separately to optimize the material matching. However, the existing device lacks the function of independent clamping and synchronous monitoring inside and outside. It can only separate the lining and the steel pipe and then test them separately. This process is cumbersome and the sample preparation cycle is long, which seriously restricts the research and development efficiency of new materials for lined oil pipelines. To solve the above problems, the following structure was invented.

[0019] like Figures 1-12 The device shown is a tensile yield strength testing device for lined oil pipelines, comprising a testing platform 1, a testing frame 2, an outer pipe 8, and an inner pipe 9. The lined oil pipeline consists of an outer pipe 8 and a metal inner pipe 9. During the research and development stage of metal-lined oil pipelines, a separate inner and outer layer production process is adopted to prevent the lining from adhering to the steel pipe, allowing for independent testing and evaluation of the mechanical properties of the two metal materials. This provides data support for optimizing material selection and wall thickness matching. The testing frame 2 is fixedly connected to the top of the testing platform 1. A movable seat 3 that can move up and down is provided on the inner side of the testing frame 2. A fixed seat 4 is fixedly connected to the top of the testing platform 1 relative to the inner side of the testing frame 2. The movable seat 3 is driven by a servo motor to achieve self-moving up and down movement via a ball screw pair. When the motor rotates, it is converted into a linear lifting motion of the moving seat 3. It works in conjunction with the linear guide rail on the inner side of the test frame 2 to guide and limit the movement, ensuring that the movement trajectory is accurate and stable, thereby quickly adjusting the distance between the moving seat 3 and the fixed seat 4. Both the moving seat 3 and the fixed seat 4 are provided with an upper plate 5. The side of the upper plate 5 away from each other is provided with a lower plate 6. The side of the fixed seat 4 and the moving seat 3 close to each other is provided with an external clamp 7 for clamping the outer tube 8. The external clamp 7 adopts a hydraulically driven claw structure. The wedge-shaped slider is pushed by the oil cylinder to radially retract, so that the claws hug the outer wall of the outer tube 8, realizing the rapid clamping and reliable fixation of the outer tube 8. This is a mature technology in the prior art, and will not be described in detail here. The upper plate 5 is respectively set through the outer wall of the moving seat 3 and the fixed seat 4 on the side close to each other. A downward force sensor 14 is fixedly connected to one side of the upper plate 5. The sensing end of the downward force sensor 14 is fixedly connected to the outer wall of the outer clamp 7. A cylinder 10 is inserted through the inner side of the outer clamp 7. The top of the cylinder 10 is inserted through the top of the upper plate 5. The cylinder 10 is fixedly connected inside the lower plate 6. An upper force sensor 11 is fixedly connected to one side of the two lower plates 6. An upper electromagnet 34 is fixedly connected to the sensing end of the upper force sensor 11. The cylinder 10 is made of iron. The side end of the cylinder 10 is adsorbed and fixed on the upper electromagnet 34. Both the upper force sensor 11 and the downward force sensor 14 work based on the strain effect principle. When the elastic body is stretched, it produces a small deformation. The strain gauge attached to the surface of the elastic body changes its resistance accordingly. The resistance change is converted into a voltage signal through a Wheatstone bridge. After amplification and conditioning, an electrical signal proportional to the tensile force is output, realizing accurate measurement and real-time monitoring of the load. The cylinder 10 is provided with an internal support mechanism for clamping the inner tube 9. An upper hydraulic telescopic cylinder 12 is fixedly connected to the middle of the top of the movable seat 3. A pair of lower hydraulic telescopic cylinders 13 are fixedly connected to both sides of the top of the movable seat 3. The output end of the upper hydraulic telescopic cylinder 12 passes through the movable seat 3 and is fixedly connected to the top of the upper tension sensor 11. The output end of the lower hydraulic telescopic cylinder 13 passes through the movable seat 3 and the lower plate 6 and is fixedly connected to the top of the upper plate 5. One of the upper plates 5 and one of the lower plates 6 are longitudinally slidably connected to the inside of the movable seat 3. One of the upper plates 5 and one of the lower plates 6 are fixedly connected to the inside of the fixed seat 4.

[0020] The internal support mechanism includes a central hydraulic telescopic cylinder 15, an internal support block 16, and a fixed cylinder 17. The fixed cylinder 17 is fixedly connected to the side of the cylinder 10 that is close to it. There are two pairs of internal support blocks 16. Each pair of internal support blocks 16 is slidably connected to both sides of the inside of the fixed cylinder 17. Side plates 18 are provided on both the front and rear sides of the inside of the fixed cylinder 17. The side plates 18 are fixedly connected to the side walls of the internal support blocks 16 on both sides. An upper rod 19 is fixedly connected to the side of the side plates 18 that is close to it. A pressing block 20 is fixedly connected between the side plates 18. The pressing block 20 is inclined on both sides. The central hydraulic telescopic cylinder 15 is fixedly connected to the sensing end of the upper tension sensor 11. The output end of the central hydraulic telescopic cylinder 15 passes through the cylinder 10 and is fixedly connected to a pull rod 21. The pull rod 21 is fixedly connected to the side wall of the pressing block 20.

[0021] Each side plate 18 is provided with a fixing plate 22 on the side away from the inner support block 16. Three upper springs 23 are fixedly connected between the fixing plate 22 and the side plate 18. The fixing plate 22 is fixedly connected to the inside of the fixing cylinder 17.

[0022] When testing the tensile yield strength of the lined oil pipeline, a separate production process for the inner and outer layers is adopted during the research and development and manufacturing of the lined oil pipeline, so that the inner lining and the steel pipe do not stick together. Then, during the test, the outer pipe 8 and the inner pipe 9 of the lined oil pipeline are placed in the test frame 2. The fixing cylinder 17 is inserted into both ends of the inner pipe 9. Then, the hydraulic telescopic cylinder 15 is activated to drive the pull rod 21 and the extrusion block 20 to move. At this time, the inclined surface of the extrusion block 20 will press the arc surface of the upper rod 19, thereby pushing the upper rod 19, the side plate 18 and the inner support block 16 to move to both sides, thereby tightening the inner support block 16 against the inner wall of the inner pipe 9. At the same time, the upper spring 23 is stretched. Then, the outer pipe 8 of the lined oil pipeline is clamped and fixed by the outer clamp 7, and the installation is completed. First, control the upper hydraulic telescopic cylinder 12 to start, driving the upper tension sensor 11, lower plate 6, upper electromagnet 34, middle hydraulic telescopic cylinder 15 and cylinder 10 to move upward together. At the same time, it drives the upper fixed cylinder 17 to move upward together. Since the inner support block 16 on the fixed cylinder 17 is tightly supported on the inner wall of the inner tube 9, it will pull the inner tube 9 to move upward together, realizing the tensile detection of the inner tube 9 (during this process, the upper tension sensor 11 monitors the tensile data of the inner tube 9 in real time). At the same time, control the lower hydraulic telescopic cylinder 13 to move upward, thereby driving the upper plate 5, lower tension sensor 14 and outer clamp 7 to move upward, realizing the tensile detection of the outer tube 8 (during this process, the lower tension sensor 14 monitors the tensile data of the outer tube 8 in real time).

[0023] In summary, through the design of the above structure and the adoption of a separate production process for the inner and outer layers during the R&D stage of metal-lined oil pipelines, the inner lining and the steel pipe are not adhered to each other. During testing, the outer pipe 8 is directly clamped by the outer clamp 7, and the inner pipe 9 is independently supported by the inner support mechanism. Then, the upper hydraulic telescopic cylinder 12 and the lower hydraulic telescopic cylinder 13 are controlled to stretch synchronously, and the upper tension sensor 11 and the lower tension sensor 14 are monitored separately. This allows for the simultaneous acquisition of the yield strength, elastic modulus, and deformation characteristics of the steel pipe and the metal lining, truly reflecting the independent mechanical behavior of the two metal materials. This provides accurate data support for optimizing the selection of inner and outer layer materials and wall thickness matching, significantly improving R&D efficiency and testing reliability.

[0024] Based on the above embodiments, it was found during use that although the above can achieve simultaneous independent tensile testing of the lining and the steel pipe, the steel pipe end of the lined oil pipeline still needs to be flared and yield tested during the research and development stage to evaluate its processing and forming performance. The existing device still cannot directly switch to the flaring test mode on the basis of tensile testing. Researchers need to transfer the sample to a special flaring equipment for secondary clamping and testing, which leads to changes in the positioning reference and interruption of the testing continuity during the sample transfer process. In addition, the two sets of equipment occupy a large space and have high investment costs, which makes it difficult to meet the needs of rapid joint testing of multiple mechanical properties during the research and development stage of lined oil pipelines. To solve the above problems, the above structure has been further improved.

[0025] Below the upper fixed cylinder 17 is a lower frame 24. The bottom end of the upper extrusion block 20 is fixedly connected to a T-shaped block 25, and the T-shaped block 25 passes through the bottom end of the lower frame 24. Several lower springs 26 are fixedly connected between the outer wall of the T-shaped block 25 and the bottom of the lower frame 24. Both cylinders 10 have flared rings 27 on their outer walls. A pair of support frames 28 are fixedly connected to the inner side of the flared rings 27. Top blocks 29 are fixedly connected to the top of the outer walls of the two pull rods 21. The top blocks 29 abut against the bottom end of the support frames 28. Vertical grooves 30 are opened on both sides of the outer wall of the cylinder 10. The support frames 28 are slidably connected to the inner side of the vertical grooves 30. Top springs 40 are fixedly connected between the side wall of the support frames 28 and the inner side of the vertical grooves 30.

[0026] Electromagnetic rings 31 are fixedly connected through the fixed cylinder 17 on the side near the cylinder 10. The flared ring 27 is made of iron. Several right-angled blocks 32 with inclined surfaces are fixedly connected at equal intervals at the bottom of the upper fixed cylinder 17. Several top grooves 33 are opened at equal intervals at the top of the lower frame 24. Several right-angled blocks 32 are inserted into the inner side of the corresponding top grooves 33. Side frames 35 are slidably connected through the outer wall of the lower frame 24 relative to the position next to the top grooves 33. A lower rod 36 is fixedly connected to the inner side of the side frame 35. A baffle 37 is provided on the inner side of the side frame 35. The baffle 37 is fixedly connected to the inner side of the top groove 33. A bottom spring 38 is fixedly connected between the side wall of the baffle 37 and the inner side of the side frame 35. Lower electromagnets 39 are fixedly connected to the front and rear sides of the upper plate 5. The lower electromagnets 39 are set between the upper plate 5 and the lower plate 6. The outer wall of the lower plate 6 is made of iron.

[0027] When a flaring yield test is required on the lining oil pipeline under development, firstly, the lower electromagnet 39 is energized to fix the upper plate 5 and lower plate 6 together. Then, the upper electromagnet 34 is de-energized to disconnect the connection between the upper electromagnet 34 and the cylinder 10 (since the cylinder 10 is fixedly connected to the lower plate 6, it is now connected to the upper plate 5). Next, the hydraulic telescopic cylinder 15 is activated to move the pull rod 21 and the compression block 20 downwards. During this process, the top block 29 moves downwards, thereby releasing the compression on the support frame 28. Subsequently, the top spring... The spring 40 pushes the support frame 28 to reset, thereby pushing the flared ring 27 to move to the outer wall of the fixed cylinder 17. Then, the electromagnetic ring 31 can be energized to attract and fix the flared ring 27 to the fixed cylinder 17. Then, the upper hydraulic telescopic cylinder 15 continues to drive the extrusion block 20 and T-shaped block 25 to move downward. During this process, the lower frame 24 will be moved out from the bottom of the fixed cylinder 17, thereby driving the lower rod 36 to move away from the inclined surface of the right-angle block 32, releasing the extrusion on the lower rod 36. Then, under the elastic force of the bottom spring 38, multiple side frames 35 are pushed out from the lower frame 24. Then, the inner tube 9 can be pulled out from the bottom of the outer tube 8, and the bottom end of the outer tube 8 can be placed on the lower outer clamp 7. The bottom of the inner tube 9 can be pressed against the lower flared ring 27. Then, the moving seat 3 is controlled to move down (while the upper hydraulic telescopic cylinder 12 and the lower hydraulic telescopic cylinder 13 are controlled to drive the upper plate 5 and the lower plate 6 to move up, leaving space for subsequent downward pressure). At this time, the upper flared ring 27 will be moved to the top of the outer tube 8, and the side frame 35 will be moved to the top of the inner tube 9. Then, the lower hydraulic telescopic cylinder 13 can be controlled to start and drive the upper plate 5 to move down. At this time, the lower electromagnet 39 will drive the lower plate 6 and the cylinder 10 to move down (at this time, the upper outer clamp 7 is in the open state and will not contact the outer wall of the outer tube 8). Thus, by driving the cylinder 10, the fixed cylinder 17 and the flared ring 27 to move down, the flaring yield test of the top of the outer tube 8 can be achieved (during this process, the pressure data of the outer tube 8 is monitored by the downward force sensor 14). After the lower hydraulic telescopic cylinder 13 is activated, the upper hydraulic telescopic cylinder 12 can be activated accordingly, thereby pushing the upper tension sensor 11 and the middle hydraulic telescopic cylinder 15 to move downward together. Then, through the pull rod 21 and the extrusion block 20, the top of the lower frame 24 is pushed, causing the lower frame 24 and the side frame 35 to move downward. In turn, the side frame 35 pushes the top of the inner tube 9 downward, so that the inner tube 9 is extruded on the lower flaring ring 27, realizing the flaring yield test of the inner tube 9 (during this process, the pressure data of the inner tube 9 is monitored in real time by the two upper tension sensors 11).

[0028] In summary, the above structural design enables the internal support mechanism to be quickly adjusted to the flaring yield test mode. During the test, the inner tube 9 moves down to expose the top of the outer tube 8, and the lower outer clamp 7 restricts the displacement of the outer tube 8. The two fixed cylinders 17 are converted into flaring rings 27 by the middle hydraulic telescopic cylinder 15. The upper flaring ring 27 is pressed against the inner wall of the outer tube 8, and the lower flaring ring 27 is pressed against the inner wall of the inner tube 9. At the same time, the side frame 35 on the lower frame 24 extends and is pressed against the top of the inner tube 9. Then, the upper hydraulic telescopic cylinder 12 can be controlled to drive the middle hydraulic telescopic cylinder 15 and the side frame 35 to move down, squeezing the inner tube 9. The lower flaring ring 27 is used to flare the bottom outer wall of the inner tube 9. At the same time, the lower hydraulic telescopic cylinder 13 drives the cylinder 10 and the upper flaring ring 27 to move down, flaring the top of the outer tube 8, realizing the synchronous flaring test of the steel pipe and the metal lining and their independent monitoring.

[0029] The foregoing has shown and described the basic principles, main features, and advantages of the present invention.

[0030] Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A device for testing the tensile yield strength of an inner-lined oil pipeline, comprising a test platform (1), a test frame (2), an outer pipe (8), and an inner pipe (9), wherein the test frame (2) is fixedly connected to the top of the test platform (1), characterized in that, The test frame (2) is provided with a movable seat (3) that can move up and down on its inner side. The top of the test platform (1) is fixedly connected to a fixed seat (4) relative to the inner side of the test frame (2). The movable seat (3) and the fixed seat (4) are both provided with an upper plate (5). The upper plate (5) is provided with a lower plate (6) on the side away from each other. The fixed seat (4) and the movable seat (3) are provided with an external clamp (7) for clamping the outer tube (8) on the side close to each other. The upper plate (5) is provided through the outer wall of the movable seat (3) and the fixed seat (4) on the side close to each other. A pull-down force sensor (14) is fixedly connected to one side of the upper plate (5). The sensing end of the pull-down force sensor (14) is fixedly connected to the outer wall of the outer clamp (7). A cylinder (10) is provided through the inner side of the outer clamp (7). The top of the cylinder (10) is provided through the top of the upper plate (5). The cylinder (10) is fixedly connected through the inside of the lower plate (6). An upper pull-down force sensor (11) is fixedly connected to one side of the two lower plates (6). An upper electromagnet (34) is fixedly connected to the sensing end of the upper pull-down force sensor (11). The cylinder (10) is made of iron. The side end of the cylinder (10) is adsorbed and fixed on the upper electromagnet (34). The cylinder (10) is provided with an inner support mechanism for clamping the inner tube (9). The upper hydraulic telescopic cylinder (12) is fixedly connected to the middle of the top of the movable seat (3), and a pair of lower hydraulic telescopic cylinders (13) are fixedly connected to both sides of the top of the movable seat (3).

2. The tensile yield strength testing device for lined oil pipelines according to claim 1, characterized in that, The output end of the upper hydraulic telescopic cylinder (12) passes through the movable seat (3) and is fixedly connected to the top of the upper tension sensor (11). The output end of the lower hydraulic telescopic cylinder (13) passes through the movable seat (3) and the lower plate (6) and is fixedly connected to the top of the upper plate (5). One of the upper plates (5) and one of the lower plates (6) are longitudinally slidably connected to the inside of the movable seat (3). One of the upper plates (5) and one of the lower plates (6) are fixedly connected to the inside of the fixed seat (4).

3. The tensile yield strength testing device for lined oil pipelines according to claim 1, characterized in that, The internal support mechanism includes a central hydraulic telescopic cylinder (15), an internal support block (16), and a fixed cylinder (17). The fixed cylinder (17) is fixedly connected to the cylinder (10) on one side close to it. There are two pairs of internal support blocks (16). Each pair of internal support blocks (16) is slidably connected to both sides of the inside of the fixed cylinder (17). Side plates (18) are provided on both the front and rear sides of the inside of the fixed cylinder (17). The side plates (18) are fixedly connected to the side walls of the internal support blocks (16) on both sides respectively. An upper rod (19) is fixedly connected to the side of the side plates (18) close to each other. A pressing block (20) is fixedly connected between the side plates (18). The pressing block (20) is inclined on both sides. The central hydraulic telescopic cylinder (15) is fixedly connected to the sensing end of the upper tension sensor (11). The output end of the central hydraulic telescopic cylinder (15) passes through the cylinder (10) and is fixedly connected to a pull rod (21). The pull rod (21) is fixedly connected to the side wall of the pressing block (20).

4. The tensile yield strength testing device for lined oil pipelines according to claim 3, characterized in that, Each side plate (18) away from the inner support block (16) is provided with a fixing plate (22). Three upper springs (23) are fixedly connected between the fixing plate (22) and the side plate (18). The fixing plate (22) is fixedly connected to the inside of the fixing cylinder (17).

5. The tensile yield strength testing device for an inner-lined oil pipeline according to claim 3, characterized in that, A lower frame (24) is provided below the upper fixed cylinder (17). A T-shaped block (25) is fixedly connected to the bottom end of the upper extrusion block (20), and the T-shaped block (25) is set through the bottom end of the lower frame (24). Several lower springs (26) are fixedly connected between the outer wall of the T-shaped block (25) and the bottom of the lower frame (24). Both outer walls of the two cylinders (10) are provided with flared rings (27). A pair of support frames (28) are fixedly connected to the inner side of the flared rings (27). Top blocks (29) are fixedly connected to the top of the outer walls of the two pull rods (21). The top blocks (29) abut against the bottom end of the support frames (28). Vertical grooves (30) are opened on both sides of the outer wall of the cylinder (10). The support frames (28) are longitudinally slidably connected to the inner side of the vertical grooves (30). Top springs (40) are fixedly connected between the side wall of the support frames (28) and the inner side of the vertical grooves (30).

6. The tensile yield strength testing device for an inner-lined oil pipeline according to claim 5, characterized in that, Electromagnetic rings (31) are fixedly connected through the fixed cylinder (17) on the side near the cylinder (10), and the flared ring (27) is made of iron.

7. The tensile yield strength testing device for lined oil pipelines according to claim 5, characterized in that, The bottom of the upper fixed cylinder (17) is fixedly connected with several right-angled blocks (32) with inclined surfaces at equal intervals. The top of the lower frame (24) is provided with several top grooves (33) at equal intervals. Several right-angled blocks (32) are inserted into the inner side of the corresponding top grooves (33). The outer wall of the lower frame (24) is slidably connected with side frames (35) at positions relative to the top grooves (33). The inner side of the side frames (35) is fixedly connected with a lower rod (36). The inner side of the side frames (35) is provided with baffles (37). The baffles (37) are fixedly connected to the inner side of the top grooves (33). The side wall of the baffles (37) and the inner side of the side frames (35) are fixedly connected with a bottom spring (38).

8. The tensile yield strength testing device for an inner-lined oil pipeline according to claim 1, characterized in that, The upper plate (5) located above is fixedly connected to both the front and rear sides with lower electromagnets (39). The lower electromagnets (39) are arranged between the upper plate (5) and the lower plate (6). The outer wall of the lower plate (6) is made of iron.

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