Whole pipe bending test device suitable for oil and gas pipeline and test method of whole pipe bending test device

Abstract

The invention belongs to the technical field of pipeline bending test equipment, and relates to a whole pipe bending test device suitable for oil and gas pipelines, which comprises a bottom frame, a supporting platform, a lower clamping frame, a lower supporting seat, an upper clamping frame and an upper supporting seat, the two supporting platforms are symmetrically arranged on the bottom frame. The lower supporting seat is placed on the supporting platform, and the placement positions of the supporting platform and the lower supporting seat are adjusted according to the length of the test tube; the lower clamping frame is hinged to the upper side of the lower supporting seat, and the upper clamping frame is hinged to the lower side of the upper supporting seat. A channel capable of penetrating through a test tube is pre-arranged in each of the lower clamping frame and the upper clamping frame; during testing, the upper supporting base is connected to an upper platform of a press, the bottom frame is placed on a lower platform of the press, a load is applied to the steel pipe, when the steel pipe is bent, the upper clamping frame rotates relative to the upper supporting base, local stress concentration borne by the test pipe is reduced, and the testing precision is improved; the sizes of the upper and lower clamping frames are adjusted to adapt to full-size bending tests of steel pipes with different pipe diameters.

Description

Technical Field

[0001] The invention belongs to the technical field of pipeline bending test equipment, and in particular relates to a whole-pipe bending test device suitable for oil and gas pipelines and a test method thereof. Background Art

[0002] The full-scale bending test of the natural gas transmission pipeline simulates the actual service load state of the oil and gas transmission pipeline. When the test pipeline is bent and deformed, the load and displacement relationship of the steel pipe and weld surface, the load and rotation angle relationship, and the stress-strain distribution are determined to determine the limit state when the test pipe is unstable, so as to evaluate the anti-buckling deformation capacity of the steel pipe under bending load and the tensile strain capacity of the girth weld. It is of great significance and research value to carry out the strain capacity research of steel pipes and evaluate whether they can meet engineering requirements.

[0003] Full-scale bending tests usually use three / four-point bending (i.e., the middle of the steel pipe is compressed and the two ends are fixed) for loading. Based on the above principles, domestic and foreign research institutions have designed and built different types of full-scale bending test devices. Full-scale bending test devices usually use hydraulic drive and displacement control to apply loads to the test steel pipe. The hydraulic drive mainly relies on hydraulic cylinders and transmission mechanisms. Generally speaking, the loading stroke and load size of the testing machine are usually designed and determined according to the test requirements, and cannot be adjusted over a large range. Therefore, the steel pipe specifications that can be completed by the testing machine have a certain range of use (such as for specific test devices, the length, diameter, strength, etc. of the test steel pipe must be within a specific range. If it exceeds this range, it exceeds the capacity of the test equipment).

[0004] In addition, full-scale bending test equipment is generally unable to adjust the loading mode (for example, four-point bending is more difficult to carry out three-point bending; three-point bending is more difficult to carry out four-point bending). With the development of technology in the field of oil and gas storage and transportation, facing the testing of pipeline samples with various specifications, a single test condition cannot fully meet the needs and has great limitations. Summary of the invention

[0005] The purpose of the present invention is to provide a whole pipe bending test device and a test method suitable for oil and gas pipelines, which solves the problem that the existing full-size bending test equipment cannot meet the requirements and has large limitations.

[0006] The present invention is achieved through the following technical solutions:

[0007] A whole pipe bending test device suitable for oil and gas pipelines, comprising a base frame, a support platform, a lower clamping frame, a lower support seat, an upper clamping frame and an upper support seat;

[0008] There are two supporting platforms which are symmetrically arranged on the base frame;

[0009] The lower support seat is placed on the support platform, and the placement positions of the support platform and the lower support seat are adjusted according to the length of the test tube;

[0010] The lower clamping frame is hinged to the upper side of the lower support seat, and the upper clamping frame is hinged to the lower side of the upper support seat;

[0011] The lower clamping frame and the upper clamping frame are both preset with channels capable of penetrating the test tube;

[0012] During the test, the upper support seat is connected to the upper platform of the press, and the base frame is placed on the lower platform of the press.

[0013] Further, one or two upper clamping frames are provided, and when one upper clamping frame is provided, it is used to realize the test loading form of three-point bending;

[0014] When two upper clamps are provided, they are used to realize the four-point bending test loading form.

[0015] Further, the upper support seat is connected to the upper clamping frame via a pin shaft;

[0016] The lower support seat is connected with the lower clamping frame through a pin shaft.

[0017] Furthermore, a supporting bottom plate is installed on the supporting platform, and a limited position pressing plate is arranged on the supporting bottom plate in a direction perpendicular to the pipeline;

[0018] The limiting pressure plate is used to prevent the lower support seat from moving in the vertical direction;

[0019] The lower support seat can slide on the support bottom plate to offset the axial load caused by the bending of the pipe.

[0020] Furthermore, the supporting base plate is fixedly connected to the supporting platform.

[0021] Furthermore, the upper clamping frame and the lower clamping frame have the same structure, both including a connecting frame and a penetration frame, the connecting frame is provided with a pin hole, and the penetration frame is provided with a penetration hole consistent with the annular cross-section of the test tube.

[0022] Furthermore, the connecting frame includes two triangular connecting plates, which are respectively connected to two sides of the supporting seat.

[0023] The present invention also discloses a test method of a whole pipe bending test device suitable for oil and gas pipelines, wherein the upper support seat is fastened to the upper platform of the press, the bottom frame is fastened to the lower platform of the press, and the test pipe is passed through the lower clamping frame and the upper clamping frame;

[0024] The press is turned on to apply a load to the test tube. When the test tube bends, the upper clamping frame rotates relative to the upper support seat, thereby reducing the local stress concentration on the test tube and improving the test accuracy.

[0025] Furthermore, the sizes of the lower clamping frame and the upper clamping frame are adjusted to adapt to the full-size bending test of steel pipes with different diameters, and the loading of steel pipes with different steel grades and wall thicknesses is completed by adapting presses with different loading capacities.

[0026] Furthermore, by adjusting the placement of the lower support seat and the support platform, it can adapt to the support of test steel pipes of different lengths;

[0027] By adjusting the number and position of the upper clamping frames, three-point or four-point bending test loading can be achieved.

[0028] Compared with the prior art, the present invention has the following beneficial technical effects:

[0029] The present invention discloses a whole pipe bending test device and test method suitable for oil and gas pipelines, the device includes a base frame, a support platform, a lower clamping frame, a lower support seat, an upper clamping frame and an upper support seat; the support platform is detachably connected above the base frame; the lower support seat is placed on the support platform, and by adjusting the placement positions of the lower support seat and the support platform, it can adapt to the support of test steel pipes of different lengths; the two clamping frames are hinged with the support seat. By adjusting the number and position of the upper clamping frames, a three-point or four-point bending test loading form can be achieved; during the test, the upper support seat is connected to the upper platform of the press, the base frame is placed on the lower platform of the press, the press is turned on, and a load is applied to the steel pipe. When the steel pipe is bent, the upper clamping frame rotates relative to the upper support seat to reduce the local stress concentration on the test pipe and improve the test accuracy; by adjusting the sizes of the upper and lower clamping frames to adapt to the full-size bending test of steel pipes of different diameters, the loading of steel pipes of different steel grades and wall thicknesses can be completed by adapting presses with different loading capacities. The present invention is based on the technical field of full-scale testing for deformation control of oil and gas pipelines and safety improvement of girth weld joints. By designing and manufacturing a device suitable for whole-pipe bending tests of oil and gas pipelines, the strain capacity of steel pipes and girth weld joints is tested and verified, and whether they can meet actual needs is evaluated. It can adapt to and meet the full-scale bending test requirements of pipelines of different specifications. The present invention has a simple structure and principle, good adaptability, and high test accuracy, and can be widely used in strain capacity assessment research and test verification of oil and gas transmission pipelines.

[0030] Furthermore, a supporting base plate is provided on the supporting platform, and the lower supporting seat can slide on the supporting base plate to offset the axial load caused by the bending of the pipeline; a limiting pressure plate is provided on the supporting base plate in a direction perpendicular to the pipeline to prevent the lower supporting seat from displacing in the vertical direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a schematic structural diagram of a whole pipe bending test device suitable for oil and gas pipelines.

[0032] Among them, 1. base frame; 2. support platform; 3. lower clamping frame; 4. lower support seat; 5. pin shaft; 6. upper clamping frame; 7. upper support seat; 8. connecting bolts; 9. upper platform; 10. lower platform;

[0033] Figure 2 It is a schematic diagram of the structure of the stress relief device in the present invention;

[0034] Among them, 11, a limiting pressure plate; 12, a supporting bottom plate. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clear, the following is further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, not all embodiments.

[0036] The components described and shown in the drawings and embodiments of the present invention may be arranged and designed in various configurations. Therefore, the detailed description of the embodiments of the present invention provided in the following drawings is not intended to limit the scope of the claimed invention, but merely represents a selected embodiment of the present invention. Based on the drawings and embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0037] It should be noted that the terms "comprises", "includes" or any other variations are intended to cover non-exclusive inclusion, so that a process, element, method, article or equipment that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to the process, element, method, article or equipment.

[0038] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0039] like Figure 1 As shown, the present invention discloses a whole pipe bending test device suitable for oil and gas pipelines, comprising a base frame 1, a support platform 2, a lower clamping frame 3, a lower support seat 4, a pin shaft 5, an upper clamping frame 6, and an upper support seat 7. The support platform 2 is provided with two and is symmetrically arranged on the base frame 1, and the base frame 1 and the support platform 2 are connected by bolts 8; the lower clamping frame 3 is hinged on the upper side of the lower support seat 4, and the upper clamping frame 6 is hinged on the lower side of the upper support seat 7.

[0040] The lower support seat 4 is hinged to the lower clamping frame 3 through the pin shaft 5, and the upper support seat 7 is hinged to the upper clamping frame 6 through the pin shaft 5.

[0041] Preferably, Figure 2As shown, a support base plate 12 is installed on the support platform 2 by bolts, and the support base plate 12 is fixedly connected to the support platform 2. The lower support seat 4 can slide on the support base plate 12 to offset the axial load caused by the bending of the pipeline;

[0042] A limiting pressure plate 11 is provided on the supporting bottom plate 12 in a direction perpendicular to the pipeline to prevent the lower supporting seat 4 from being displaced in the vertical direction.

[0043] like Figure 1 As shown, the upper clamping frame 6 has the same structure as the lower clamping frame 3, both of which include a connecting frame and a penetration frame. The connecting frame is provided with a pin hole, and the penetration frame is provided with a penetration hole that is consistent with the annular cross-section of the test tube.

[0044] The connecting frame comprises two triangular connecting plates which are respectively connected to two sides of the supporting seat.

[0045] Specifically, the upper support seat 7 and the lower support seat 4 have the same structure, both including a connecting plate and a plurality of triangular plates connected to the connecting plate. The triangular plates are connected to the triangular connecting plates of the connecting frame. The connecting plate of the lower support seat 4 can slide on the supporting base plate 12.

[0046] During the test, the device of the present invention was installed on presses with different loading capacities, wherein the upper support seat 7 was fastened in the T-slot of the upper platform 9 of the press by bolts, and the base frame 1 was placed on the lower platform 10 of the press and fastened in the T-slot of the lower platform 10 of the press by bolts.

[0047] The lower clamping frame 3 and the upper clamping frame 6 are both connected to the steel pipe, and the upper clamping frame 6 is consistent with the annular cross section of the pipe. When the steel pipe is bent, the upper clamping frame 6 rotates along the pin 5 to reduce the local stress concentration on the test steel pipe, and the lower support seat 4 can slide on the support bottom plate 12 to offset the axial load caused by the pipe bending, thereby improving the test accuracy.

[0048] The size of the upper and lower clamps can be adjusted to accommodate full-size bending tests of steel pipes with different diameters, and the loading of steel pipes with different steel grades and wall thicknesses can be completed by adapting presses with different loading capacities. By adjusting the placement of the lower support seat 4 and the support platform 2, it can accommodate the support of test steel pipes of different lengths. By adjusting the number and position of the upper clamps 6, a three-point or four-point bending test loading form can be achieved.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A whole pipe bending test device suitable for oil and gas pipelines, characterized in that: It comprises a base frame (1), a supporting platform (2), a lower clamping frame (3), a lower supporting seat (4), an upper clamping frame (6) and an upper supporting seat (7); Two supporting platforms (2) are provided and are symmetrically arranged on the base frame (1); The lower support seat (4) is placed on the support platform (2), and the placement positions of the support platform (2) and the lower support seat (4) are adjusted according to the length of the test tube; The lower clamping frame (3) is hinged on the upper side of the lower support seat (4), and the upper clamping frame (6) is hinged on the lower side of the upper support seat (7); The lower clamping frame (3) and the upper clamping frame (6) are both preset with a passage capable of penetrating the test tube; During the test, the upper support seat (7) is connected to the upper platform (9) of the press, and the base frame (1) is placed on the lower platform (10) of the press.

2. The whole pipe bending test device suitable for oil and gas pipelines according to claim 1, characterized in that: There is one or two upper clamping frames (6). When there is one upper clamping frame (6), it is used to realize a three-point bending test loading form; When two upper clamping frames (6) are provided, they are used to realize a four-point bending test loading form.

3. The whole pipe bending test device suitable for oil and gas pipelines according to claim 1, characterized in that: The upper support seat (7) is connected to the upper clamping frame (6) via a pin shaft (5); The lower support seat (4) is connected to the lower clamping frame (3) via a pin shaft (5).

4. The whole pipe bending test device suitable for oil and gas pipelines according to claim 1, characterized in that: A support base plate (12) is installed on the support platform (2), and a limit pressure plate (11) is arranged on the support base plate (12) in a direction perpendicular to the pipeline; The limiting pressure plate (11) is used to prevent the lower support seat (4) from being displaced in the vertical direction; The lower support seat (4) can slide on the support base plate (12) to offset the axial load caused by the bending of the pipeline.

5. The whole pipe bending test device suitable for oil and gas pipelines according to claim 4, characterized in that: The supporting base plate (12) is fixedly connected to the supporting platform (2).

6. The whole pipe bending test device suitable for oil and gas pipelines according to claim 1, characterized in that: The upper clamping frame (6) has the same structure as the lower clamping frame (3), and both comprise a connecting frame and a penetration frame. The connecting frame is provided with a pin hole, and the penetration frame is provided with a penetration hole that is consistent with the annular cross section of the test tube.

7. The whole pipe bending test device suitable for oil and gas pipelines according to claim 6, characterized in that: The connecting frame comprises two triangular connecting plates which are respectively connected to two sides of the supporting seat.

8. A test method for a whole pipe bending test device applicable to oil and gas pipelines according to any one of claims 1 to 7, characterized in that: Fasten the upper support seat (7) to the upper platform (9) of the press, fasten the bottom frame (1) to the lower platform (10) of the press, and pass the test tube through the lower clamping frame 3 and the upper clamping frame (6); The press is turned on to apply a load to the test tube. When the test tube bends, the upper clamping frame (6) rotates relative to the upper support seat (7) to reduce the local stress concentration on the test tube.

9. The test method according to claim 8, characterized in that The sizes of the lower clamping frame (3) and the upper clamping frame (6) are adjusted to adapt to full-size bending tests of steel pipes with different diameters, and the loading of steel pipes with different steel grades and wall thicknesses is completed by adapting presses with different loading capacities.

10. The test method according to claim 8, characterized in that: By adjusting the placement positions of the lower support seat (4) and the support platform (2), the support of test steel pipes of different lengths can be adapted; By adjusting the number and position of the upper clamping frames (6), a three-point or four-point bending test loading form is achieved.

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