Oil and gas pipeline nondestructive testing equipment

Abstract

The present invention discloses a nondestructive testing device for oil and gas pipelines, which relates to the field of nondestructive testing technology and includes: a vehicle body; a moving mechanism that drives the vehicle body to move; a battery module that provides power and can be charged; a solar energy conversion mechanism mounted on the vehicle body, comprising a solar panel for charging the battery module and a rotation mechanism that drives the solar panel to rotate in tandem with the sun; a remote-field eddy current excitation coil and receiving coil fixing mechanism mounted on the vehicle body, comprising: a support frame having a first arm and a second arm, the first arm having a first retractable mechanism and a first probe mounting portion, the second arm having a second retractable mechanism and a second probe mounting portion; an excitation probe disposed at the first probe mounting portion; a detection probe disposed at the second probe mounting portion, and the like. This application enables remote and automatic detection of axial cracks in oil and gas pipelines of variable diameter.

Description

Technical Field

[0001] The present invention relates to the technical field of nondestructive testing, and in particular to a nondestructive testing device for oil and gas pipelines. Background Art

[0002] Remote-field eddy current testing can detect corrosion thinning, environmental cracking, material degradation, and mechanical damage defects on the inner and outer surfaces of in-service pipelines. It also overcomes the skin effect limitations of traditional eddy current testing, expanding the detection range to the entire pipe wall thickness range. This allows for the inspection of not only non-magnetic oil and gas pipes but also other ferromagnetic pipes. The surface of the pipe to be inspected does not need to be cleaned; the detection probe does not need to come into contact with the inner wall of the steel pipe. Within a range of sufficient magnetization, the effect of gap changes on the test results can be ignored. The test results are unaffected by the conveying medium; and the equipment is lightweight and suitable for mobile operations.

[0003] The far-field eddy current method was originally developed specifically for pipeline defect detection, but has recently begun to be applied to flat-plate inspections. The original far-field eddy current probe features an excitation coil coaxial with the pipe, flowing a low-frequency alternating current, and multiple small detection coils distributed circumferentially at a distance twice the pipe's inner diameter from the excitation coil (the far-field region). Two distinct energy transfer pathways exist between the excitation coil and the detection coils in the far-field region: a direct coupling energy transfer path within the pipe, characterized by exponential decay with increasing distance from the excitation coil; another energy transfer path, near the excitation coil, through the pipe wall to the exterior, then back inside the pipe near the detection coils, where it is detected. This energy also decays exponentially, but at a much smaller rate than the direct coupling energy. The result is that the total detection signal on the inner wall is almost entirely the result of direct coupling in the region close to the excitation coil (the near-field region), while in the far-field region, it is almost entirely the result of far-field coupling re-entering the pipe wall. Far-field eddy currents often use the phase difference between the detection signal and the excitation signal as the target signal to be measured. According to the skin effect formula, this phase difference is proportional to the thickness of the pipe wall through which the far-field coupled energy passes. Therefore, the principle of far-field eddy current detection of volumetric corrosion defects can be intuitively explained. People's confidence in applying far-field eddy current methods to crack detection comes from the sensitive response of traditional eddy currents to crack defects on metal surfaces. Subsequent research on far-field eddy current crack detection has found that the traditional far-field eddy current method of detecting cracks by interrupting circumferential eddy currents due to axial cracks is indeed feasible for detecting axial crack defects in non-ferromagnetic conductive pipes. However, this method is not practical for ferromagnetic pipes because the effect of circumferential cracks on the axial magnetic field is stronger than the effect of axial cracks on circumferential eddy currents, resulting in a more significant response of circumferential cracks than axial cracks. Summary of the Invention

[0004] For example, Sun Yushi, Qu Minxing, and Si Jiatun from Nanjing University of Aeronautics and Astronautics proposed three improved technologies for far-field eddy current probes, including the addition of a magnetic loop to the excitation coil, the addition of a magnetic loop to the receiving coil, and the placement of a compensation coil between the excitation and receiving coils. These improvements resulted in high signal amplitude, low excitation power, and a short probe axial length. These improvements reduced the application difficulty of far-field eddy currents and reduced the probe length to a certain extent, but they still made it difficult to pass through pipe elbows. Another example is Chen Peihua, Huang Pingjie, Li Guohou, and Zhou Zekui from Zhejiang University, who proposed a metal defect eddy current detection device and probe. This device combines conventional eddy current and low-frequency far-field eddy current technologies to detect defects in sheet or tubular metal materials. However, the aforementioned tubular shape and its probe structure only allow for straight tubes and can only be placed on the pipe axis. When placed circumferentially for testing, this is equivalent to applying only conventional eddy current testing. Therefore, at the special location of pipe elbows, the surface of the tested part is complex, making it difficult for this device to successfully detect defects. For example, Xu Zhiyuan, Lin Zhangpeng, Li Haichao, and Tan Yuanqiang from Xiangtan University proposed a pipeline elbow defect detection method and detection device based on far-field eddy currents. The main purpose is to solve technical problems such as blind spots or poor probe passability when existing eddy current detection is used for pipeline elbows. The key points of this technical solution are: using a far-field eddy current sensor consisting of two identical excitation units and one receiving unit, and the two excitation units are located on both sides of the receiving unit. The excitation unit and the receiving unit are both arranged along the circumference of the cross-section of the pipeline elbow to be detected, and the receiving unit is located in the far-field area for measuring the indirect coupled magnetic field signal. However, the angles of the two excitation units of the above-mentioned pipeline elbow defect detection method and detection device based on far-field eddy currents are fixed, and need to be remanufactured according to changes in the outer diameter of the pipeline, and are not convenient for on-site adjustment; and the test results require computer assistance, so the device requires human assistance and cannot be fully intelligent.

[0005] In order to overcome at least one of the above-mentioned defects of the prior art, the technical problem to be solved by the embodiments of the present invention is to provide an oil and gas pipeline non-destructive testing device, which can use a crawler structure to perform remote automatic detection of axial cracks in oil and gas pipelines of non-fixed diameter.

[0006] The specific technical solution of the embodiment of the present invention is:

[0007] A nondestructive testing device for oil and gas pipelines, comprising:

[0008] body of the vehicle;

[0009] A moving mechanism, which drives the vehicle body to move;

[0010] A battery module; which is used to provide power and can be charged;

[0011] a solar energy conversion mechanism mounted on the vehicle body, comprising a solar panel for charging the battery module and a rotation mechanism for driving the solar panel to rotate in accordance with the sun;

[0012] A far-field eddy current excitation coil and receiving coil fixing mechanism installed on the vehicle body includes: a support frame having a first arm and a second arm, the first arm having a first telescopic mechanism and a first probe mounting portion, the second arm having a second telescopic mechanism and a second probe mounting portion; an excitation probe arranged at the first probe mounting portion; a detection probe arranged at the second probe mounting portion; a preset angle is formed between the first telescopic mechanism and the second telescopic mechanism, the preset angle is not equal to 0 degrees and 180 degrees, and the excitation probe and the detection probe are arranged relative to each other.

[0013] Preferably, the first probe mounting portion and the second probe mounting portion are substantially parallel.

[0014] Preferably, the first telescopic mechanism includes: a first outer tube, a first groove extending along its axial direction is provided on its side wall; a first inner tube inserted in the first outer tube, the first inner tube and the first outer tube can move relative to each other, and a first threaded hole is provided on the first inner tube; a first adjusting member screwed into the first threaded hole, the first adjusting member is embedded in the first groove, thereby achieving the fixation of the first inner tube and the first outer tube.

[0015] Preferably, the second telescopic mechanism includes: a second outer tube, a second groove extending along its axial direction is provided on its side wall; a second inner tube inserted in the second outer tube, the second inner tube and the second outer tube can move relative to each other, and a second threaded hole is provided on the second inner tube; a second adjusting member screwed into the second threaded hole, and the second adjusting member is embedded in the second groove, thereby achieving the fixation of the second inner tube and the second outer tube.

[0016] Preferably, the top of the excitation probe has an excitation coil, and the outside of the excitation coil has a shielding layer; the top of the detection probe has a detection coil, and the outside of the detection coil has a shielding layer.

[0017] Preferably, the rotation mechanism includes: an outer disk having an opening with a circular cross-section; an inner disk arranged in the opening, and capable of rotating in a circumferential direction between the inner disk and the outer disk; a first servo, a housing of the first servo is fixed to the vehicle body, and an output shaft of the first servo is connected to the center of the inner disk.

[0018] Preferably, the rotation mechanism further includes: a second servo, a housing of the second servo being fixedly connected to the upper surface of the inner disk, the second servo having an output shaft extending in a horizontal direction and having a first end and a second end; a first robotic arm and a second robotic arm, one end of the first robotic arm being connected to the first end of the output shaft of the second servo, the other end of the first robotic arm being connected to the solar panel, the second robotic arm being connected to the second end of the output shaft of the second servo, and the other end of the second robotic arm being connected to the solar panel, so that the solar panel can rotate around the axis of the output shaft of the second servo.

[0019] Preferably, the oil and gas pipeline nondestructive testing device further includes:

[0020] Main control panel;

[0021] A D / A conversion module electrically connected to the main control panel, an amplifier circuit module electrically connected to the D / A conversion module, and an excitation coil of the excitation probe electrically connected to the amplifier circuit module;

[0022] A differential circuit module electrically connected to the detection coil of the detection probe, an A / D conversion module electrically connected to the differential circuit module, and the main control panel electrically connected to the A / D conversion module.

[0023] Preferably, the excitation coil has a rectangular coil structure; the detection coil has a rectangular coil structure.

[0024] Preferably, the parameters of the rectangular coil are as follows: length 70 mm, width 20 mm, height 16 mm, thickness 5 mm, conductivity 5.8×10 7 S×m -1 , the relative magnetic permeability is 1.

[0025] The technical solution of the present invention has the following significant beneficial effects:

[0026] The oil and gas pipeline nondestructive testing device disclosed in this application uses a moving mechanism to move the vehicle body. During this movement, the pipeline is positioned between the first arm and the second arm using a support frame comprising a far-field eddy current excitation coil and a receiving coil fixing mechanism mounted on the vehicle body. This allows the excitation probe on the first arm and the detection probe on the second arm to detect defects in the pipeline using far-field eddy currents. Furthermore, the oil and gas pipeline nondestructive testing device includes a solar panel and a rotating mechanism that drives the panel to rotate with the sun, allowing the panel to face the sun and convert solar energy into electrical energy for storage in a battery module. This ensures the oil and gas pipeline nondestructive testing device can operate automatically and remotely over long distances outdoors.

[0027] With reference to the following description and drawings, specific embodiments of the present invention are disclosed in detail, indicating the manner in which the principles of the present invention can be employed. It should be understood that the embodiments of the present invention are not limited in scope thereby. Within the spirit and scope of the appended claims, the embodiments of the present invention include many variations, modifications, and equivalents. Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the various components in the drawings are merely illustrative and are used to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the various components of the present invention. Those skilled in the art can select various possible shapes and proportional dimensions to implement the present invention according to specific circumstances under the guidance of the present invention.

[0029] Figure 1 2 is a three-dimensional schematic diagram of a nondestructive testing device for oil and gas pipelines according to an embodiment of the present invention;

[0030] Figure 2 Schematic diagram of the structure of the fixing mechanism of the far-field eddy current excitation coil and the receiving coil in an embodiment of the present invention;

[0031] Figure 3 Schematic diagram of the three-dimensional structure of the rotating mechanism in an embodiment of the present invention;

[0032] Figure 4 is a side view of the rotating mechanism in an embodiment of the present invention;

[0033] Figure 5 A bottom view of the rotating mechanism in an embodiment of the present invention;

[0034] Figure 6 4 is a flow chart of the principle of far-field eddy current detection in an embodiment of the present invention.

[0035] Reference numerals in the above drawings:

[0036] 1. Vehicle body; 2. Moving mechanism; 3. Battery module; 4. Solar energy conversion mechanism; 41. Solar cell panel; 42. Rotating mechanism; 421. Outer disk; 422. Inner disk; 423. First servo; 424. Second servo; 425. First robotic arm; 426. Second robotic arm; 427. Bracket; 5. Far-field eddy current excitation coil and receiving coil fixing mechanism; 51. First arm; 511. First telescopic mechanism; 512. First probe mounting part; 52. Second arm; 521. Second telescopic mechanism; 522. Second probe mounting part; 53. Excitation probe; 54. Detection probe; 55. Fixing seat. DETAILED DESCRIPTION

[0037] The details of the present invention can be more clearly understood in conjunction with the accompanying drawings and the description of the specific embodiments of the present invention. However, the specific embodiments of the present invention described herein are for illustrative purposes only and are not to be construed as limiting the present invention in any way. Based on the teachings of the present invention, skilled artisans can conceive of any possible variations based on the present invention, all of which should be considered within the scope of the present invention. It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there can be an intermediate element. The terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, internal communication between two elements, direct connection, or indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of these terms based on the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are intended only to describe specific embodiments and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] In order to be able to perform remote automatic detection of axial cracks in oil and gas pipelines with non-constant diameters, this application proposes a non-destructive testing device for oil and gas pipelines. Figure 1 This is a three-dimensional schematic diagram of a nondestructive testing device for oil and gas pipelines according to an embodiment of the present invention. Figure 2 FIG. 1 is a structural diagram of a fixing mechanism for a far-field eddy current excitation coil and a receiving coil in an embodiment of the present invention. Figure 1 and Figure 2 As shown, the oil and gas pipeline nondestructive testing device may include: a vehicle body 1; a moving mechanism 2, which drives the vehicle body 1 to move; a battery module 3; which is used to supply power and can be charged; a solar energy conversion mechanism 4 installed on the vehicle body 1, which includes a solar panel 41 for charging the battery module 3, and a rotating mechanism 42 for driving the solar panel 41 to rotate with the sun; a far-field eddy current excitation coil and receiving coil fixing mechanism 5 installed on the vehicle body 1, which includes: a support frame having a first arm 51 and a second arm 52, the first arm 51 having a first retractable mechanism 511 and a first probe mounting portion 512, the second arm 52 having a second retractable mechanism 521 and a second probe mounting portion 522; an excitation probe 53 provided on the first arm 51 at the first probe mounting portion 512; a detection probe 54 provided at the second probe mounting portion 522; a preset angle is formed between the first retractable mechanism 511 and the second retractable mechanism 521, the preset angle is not equal to 0 degrees and 180 degrees, and the excitation probe 53 and the detection probe 54 are arranged relative to each other.

[0040] The oil and gas pipeline nondestructive testing device in this application moves the vehicle body 1 by means of a moving mechanism 2. During the movement, the pipeline is placed between the first arm 51 and the second arm 52 using a support frame of a far-field eddy current excitation coil and a receiving coil fixing mechanism 5 mounted on the vehicle body 1. Thus, defects in the pipeline are detected using far-field eddy currents via an excitation probe 53 on the first arm 51 and a detection probe 54 on the second arm 52. At the same time, the oil and gas pipeline nondestructive testing device is equipped with a solar panel 41 and a rotating mechanism 42 that drives the solar panel 41 to rotate with the sun, thereby enabling the solar panel 41 to face the sun and convert solar energy into electrical energy to be stored in the battery module 3. This ensures that the oil and gas pipeline nondestructive testing device can operate automatically and remotely over long distances outdoors.

[0041] In order to better understand the oil and gas pipeline nondestructive testing device in this application, it will be further explained and illustrated below. Figure 1 As shown, the oil and gas pipeline nondestructive testing device may include: a vehicle body 1, a moving mechanism 2, a battery module 3, a solar energy conversion mechanism 4, and a far-field eddy current excitation coil and receiving coil fixing mechanism 5.

[0042] Among them, Figure 1 As shown, the vehicle body 1 extends in the horizontal direction, has a certain strength, and can generally be made of metal or materials with higher strength. It is used to install and fix other components.

[0043] like Figure 1As shown, the moving mechanism 2 is installed on the vehicle body 1, and is used to drive the vehicle body 1 to move. As a feasible method, the moving mechanism 2 may include a motor, a track wheel driven by the motor, and a track mounted on the track wheel. There may be multiple track wheels, which may be located on both sides of the vehicle body 1, and at least one of the track wheels on each side is driven by the motor to achieve the forward or backward rolling of the track on that side. Among them, there may be one motor driving the track wheel, and the motor and the track wheels on both sides may be connected by a transmission mechanism, and the state in the transmission mechanism is switched, so that the motor can control the rotation of the track wheel on one side alone, or can control the track wheels on both sides to rotate simultaneously. Of course, there may be two motors driving the track wheels, one of which drives the track wheel on one side to rotate, and the other drives the track wheel on the other side to rotate. Through this description, it can be achieved that the motor can control the rotation of the track wheel on one side alone, or can control the track wheels on both sides to rotate simultaneously. The crawler wheels and tracks can enable the oil and gas pipeline non-destructive testing device to move forward or backward in harsh environments, and the oil and gas pipeline non-destructive testing device can also turn by rotating the crawler wheels on one side.

[0044] like Figure 1 As shown, the battery module 3 is used to provide power and is capable of charging. The battery module 3 can be mounted on the vehicle body 1 and is electrically connected to the mobile mechanism 2, thereby powering the motor in the mobile mechanism 2. The battery module 3 is also electrically connected to the solar energy conversion mechanism 4. The electrical energy obtained by the solar energy conversion mechanism 4 is transmitted to the battery module 3 to charge the battery module 3. Furthermore, the battery module 3 is also electrically connected to the remote-field eddy current excitation coil and receiving coil fixing mechanism 5 to provide electrical energy, thereby enabling the remote-field eddy current excitation coil and receiving coil fixing mechanism 5 to detect pipeline defects using remote-field eddy currents.

[0045] As an option, the battery module 3 may be composed of rechargeable batteries.

[0046] like Figure 1 As shown, the solar energy conversion mechanism 4 is mounted on the vehicle body 1. The solar energy conversion mechanism 4 includes a solar panel 41 for charging the battery module 3 and a rotation mechanism 42 for driving the solar panel 41 to rotate in accordance with the sun. The solar panel 41 is electrically connected to the battery module 3 to transmit the generated electrical energy to the battery module 3. The solar panel 41 is also electrically connected to the motor in the moving mechanism 2 to provide electrical energy thereto. While the solar panel 41 can be a monocrystalline silicon solar panel, other types of panels are also acceptable.

[0047] Figure 3 Schematic diagram of the three-dimensional structure of the rotating mechanism in an embodiment of the present invention, Figure 4 is a side view of the rotating mechanism in an embodiment of the present invention, Figure 5 FIG. 1 is a bottom view of the rotating mechanism in an embodiment of the present invention, as shown in FIG. Figures 3 to 5 As shown, the rotation mechanism 42 may include an outer disk 421 having an opening with a circular cross-section; an inner disk 422 disposed within the opening, capable of circumferential rotation relative to the outer disk 421; and a first servo 423, the housing of which is fixed to the vehicle body 1, with its output shaft connected to the center of the inner disk 422. Specifically, the outer disk 421 and the inner disk 422 may be made of metal, such as a strong and lightweight aluminum alloy. The outer disk 421 is a large annular structure with an opening with a circular cross-section. The inner disk 422 is a circular disk that fits within the opening of the outer disk 421, nesting within the outer disk 421 and the inner disk 422. The outer disk 421 and the inner disk 422 are coaxially arranged and capable of circumferential rotation relative to each other. The housing of the first servo 423 can be secured to the upper end surface of the vehicle body 1 via fasteners, thereby securing the outer disc 421 and, in turn, protecting and limiting the inner disc 422. The output shaft of the first servo 423 is connected to the center of the inner disc 422. The first servo 423 is a horizontal, circumferentially adjustable servo, used to controllably rotate the inner disc 422 relative to the outer disc 421 in the circumferential direction, thereby adjusting the circumferential orientation of the solar panel 41 so that it always faces the sun. This increases the area and intensity of solar radiation on the solar panel 41.

[0048] like Figures 3 to 5 As shown, the rotating mechanism 42 may include: a second servo 424, the shell of the second servo 424 is fixedly connected to the upper surface of the inner disk 422, and the second servo 424 has an output shaft extending in a horizontal direction with a first end and a second end; a first robotic arm 425 and a second robotic arm 426, one end of the first robotic arm 425 is connected to the first end of the output shaft of the second servo 424, the other end of the first robotic arm 425 is connected to the solar cell panel 41, the second robotic arm 426 is connected to the second end of the output shaft of the second servo 424, and the other end of the second robotic arm 426 is connected to the solar cell panel 41, so that the solar cell panel 41 can rotate around the axis of the output shaft of the second servo 424.

[0049] As feasible, Figure 3 and Figure 4As shown, a connecting piece is fixedly mounted on the first end of the output shaft. The connecting piece has multiple through-holes. Through-holes are also formed on the first mechanical arm 425 at positions corresponding to the through-holes on the connecting piece. Screws are inserted through the through-holes and nuts are tightened to secure the connecting piece and the first mechanical arm 425. This allows the output shaft to rotate the connecting piece, which in turn drives the first mechanical arm 425. Similarly, the second end of the output shaft can be fixedly connected to the second mechanical arm 426 in the same manner. An "X"-shaped support member can be connected to the lower end surface of the solar panel 41 to support and secure the solar panel 41. The other end of the first mechanical arm 425 and the other end of the second mechanical arm 426 are connected to the support member to achieve connection with the solar panel 41. The first mechanical arm 425 and the second mechanical arm 426 are arranged opposite each other and remain parallel. When the output shaft of the second servo 424 rotates, the first robotic arm 425 and the second robotic arm 426 can drive the solar panel 41 to rotate around the axis of the output shaft of the second servo 424, thereby achieving a 180° pitch angle adjustment of the solar panel 41, thereby enabling the solar panel 41 to track the altitude angle of the sun. This can increase the intensity of solar radiation on the solar panel 41 and ensure that the sun shines directly on the solar panel 41 as much as possible.

[0050] like Figure 2 As shown, the far-field eddy current excitation coil and receiving coil fixing mechanism 5 is installed on the vehicle body 1. The far-field eddy current excitation coil and receiving coil fixing mechanism 5 may include: a support frame having a first arm 51 and a second arm 52, the support frame having a fixing seat, and the fixing seat is fixedly mounted on the vehicle body 1 by bolts or other fixing parts. The first arm 51 and the second arm 52 are located on the side of the vehicle body 1, and both extend outward, so that during the movement of the oil and gas pipeline non-destructive testing device, the pipeline located outside the side of the oil and gas pipeline non-destructive testing device can be inspected for defects. The first arm 51 and the second arm 52 can be fixedly connected together, or they can be connected together in the form of a hinge connection, so that the first arm 51 and the second arm 52 can rotate relative to each other to adjust the angle between the first arm 51 and the second arm 52.

[0051] like Figure 2As shown, the first arm 51 has a first telescopic mechanism 511 and a first probe mounting portion 512, while the second arm 52 has a second telescopic mechanism 521 and a second probe mounting portion 522. The first probe mounting portion 512 is located at the end of the first arm 51, while the second probe mounting portion 522 is located at the end of the second arm 52. The first probe mounting portion 512 and the second probe mounting portion 522 are substantially parallel. The first telescopic mechanism 511 can be extended and contracted along its axis, thereby adjusting the length of the first arm 51. The second telescopic mechanism 521 can be extended and contracted along its axis, thereby adjusting the length of the second arm 52. Optionally, the first telescopic mechanism 511 includes: a first outer tube having a first groove extending along its axis on its sidewall; a first inner tube inserted into the first outer tube, the first inner tube and the first outer tube being movable relative to each other, the first inner tube having a first threaded hole; and a first adjusting member threaded into the first threaded hole, the first adjusting member being embedded in the first groove to secure the first inner tube to the first outer tube. The second telescopic mechanism 521 comprises: a second outer tube having a second groove extending along its axial direction on its sidewall; a second inner tube inserted into the second outer tube, allowing relative movement between the second inner tube and the second outer tube, and a second threaded hole formed in the second inner tube; and a second adjusting member threaded into the second threaded hole, which engages in the second groove to secure the second inner tube to the second outer tube. Loosening the first adjusting member allows the first outer tube and the first inner tube to move relative to each other along their axial direction, and tightening the first adjusting member locks the first outer tube and the first inner tube. The second telescopic mechanism 521 operates similarly.

[0052] The first retractable mechanism 511 and the second retractable mechanism 521 form a preset angle between them, and the preset angle is not equal to 0 degrees or 180 degrees. The first retractable mechanism 511 and the second retractable mechanism 521 can be used to adjust the distance between the first probe mounting portion 512 and the second probe mounting portion 522, thereby enabling the oil and gas pipeline nondestructive testing device to perform defect detection on pipelines of different sizes using remote-field eddy currents.

[0053] like Figure 2 As shown, the far-field eddy current excitation coil and receiving coil fixing mechanism 5 may include: an excitation probe 53 disposed at a first probe mounting portion 512; and a detection probe 54 disposed at a second probe mounting portion 522. The excitation probe 53 and the detection probe 54 are disposed relative to each other, so that the excitation probe 53 generates far-field eddy currents to detect the pipe wall condition, and the detection probe 54 is used to receive electromagnetic induction signals affected by the pipe wall condition.

[0054] The top of the excitation probe 53 has an excitation coil, and the outside of the excitation coil has a shielding layer; the top of the detection probe 54 has a detection coil, and the outside of the detection coil has a shielding layer. In order to better generate far-field eddy currents and receive electromagnetic induction signals affected by the pipe wall conditions, preferably, the excitation coil has a rectangular coil structure, and a copper transmitting coil can be used. The detection coil has a rectangular coil structure, and a copper receiving coil can be used. The coils in the excitation coil and the detection coil can be arranged in an array along the radial direction of the pipeline. The rectangular coil can effectively improve the excitation and detection signal-to-noise ratio. According to finite element analysis, it is the optimal coil structure shape. In conjunction with the crawler mobile mechanism 2, the excitation coil and the detection coil can simultaneously transmit and receive magnetic field monitoring signals that can reflect pipe wall information in an optimal structure.

[0055] Through experiments, it was found that when the parameters of the rectangular coil are as follows, the excitation coil and the detection coil have better detection effects. The specific parameters are: length 70mm, width 20mm, height 16mm, thickness 5mm, conductivity 5.8×10 7 S×m -1 , the relative magnetic permeability is 1. Considering the size of the track wheel body and the results of finite element analysis, the conductivity is a customized value for a batch of materials, and the above parameters are selected as the optimal design solution.

[0056] Figure 6 FIG. 1 is a flow chart showing the principle of far-field eddy current detection in an embodiment of the present invention. Figure 6 As shown, the oil and gas pipeline nondestructive testing device can include: a main control panel, which can be an STM32 panel; a D / A conversion module electrically connected to the main control panel; an amplifier circuit module electrically connected to the D / A conversion module; an excitation coil of the excitation probe 53 electrically connected to the amplifier circuit module; a differential circuit module electrically connected to the detection coil of the detection probe 54; an A / D conversion module electrically connected to the differential circuit module; and the main control panel electrically connected to the A / D conversion module. The main control panel can be electrically connected to the battery module 3 and the solar panel 41 to receive electrical energy during operation. The main control panel generates a control signal, which is converted by the D / A conversion module, amplified by the amplifier circuit module, and then applied to the excitation coil, generating magnetic lines of force outside the transmitting coil, thereby generating far-field eddy currents to detect the condition of the pipe wall. The receiving coil in the detection probe 54 receives the electromagnetic induction signal affected by the condition of the pipe wall, that is, it detects the far-field eddy current signal. Since the signal is extremely weak, the common-mode signal is suppressed by the differential circuit module and the differential-mode signal is amplified to increase the signal gain; it is then converted by the A / D conversion module to obtain far-field eddy current data that can reflect the condition of the pipe wall, and then stored in the memory in the main control panel to facilitate subsequent centralized analysis and processing of the data.

[0057] Preferably, the oil and gas pipeline nondestructive testing device may include a filtering and noise removal module connected between the A / D conversion module and the differential circuit module. The signal amplified by the differential circuit module is filtered and denoised by the filtering and noise removal module to improve the accuracy and reliability of the signal.

[0058] All articles and references disclosed, including patent applications and publications, are incorporated herein by reference for all purposes. The term "essentially consisting of..." describing a combination should include the identified elements, ingredients, parts or steps and other elements, ingredients, parts or steps that do not substantially affect the basic novel features of the combination. The use of the terms "comprising" or "including" to describe the combination of elements, ingredients, parts or steps herein also contemplates an embodiment that is essentially composed of these elements, ingredients, parts or steps. By using the term "may", it is intended to illustrate that any attribute described that "may" include is optional. Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure "one" or "an" used to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0059] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A nondestructive testing device for oil and gas pipelines, characterized in that: The oil and gas pipeline nondestructive testing device comprises: body of the vehicle; A moving mechanism, which drives the vehicle body to move; A battery module; which is used to provide power and can be charged; a solar energy conversion mechanism mounted on the vehicle body, comprising a solar panel for charging the battery module and a rotation mechanism for driving the solar panel to rotate in accordance with the sun; A far-field eddy current excitation coil and receiving coil fixing mechanism mounted on the vehicle body, comprising: a support frame having a first arm and a second arm, the first arm having a first retractable mechanism and a first probe mounting portion, the second arm having a second retractable mechanism and a second probe mounting portion; an excitation probe disposed at the first probe mounting portion; a detection probe disposed at the second probe mounting portion; a preset angle being formed between the first retractable mechanism and the second retractable mechanism, the preset angle not being equal to 0 degrees and 180 degrees, the excitation probe and the detection probe being disposed relative to each other; and the first probe mounting portion being substantially parallel to the second probe mounting portion. While the moving mechanism drives the vehicle body to move, the pipeline is placed between the first arm and the second arm using the far-field eddy current excitation coil installed on the vehicle body and the support frame of the receiving coil fixing mechanism, so that defects in the pipeline are detected using far-field eddy currents through the excitation probe on the first arm and the detection probe on the second arm.

2. The oil and gas pipeline nondestructive testing device according to claim 1, characterized in that: The first telescopic mechanism includes: a first outer tube, a first groove extending along its axial direction is provided on its side wall; a first inner tube inserted in the first outer tube, the first inner tube and the first outer tube can move relative to each other, and a first threaded hole is provided on the first inner tube; a first adjusting member screwed into the first threaded hole, and the first adjusting member is embedded in the first groove, thereby achieving fixation of the first inner tube and the first outer tube.

3. The oil and gas pipeline nondestructive testing device according to claim 1, characterized in that: The second telescopic mechanism includes: a second outer tube, a second groove extending along its axial direction is provided on its side wall; a second inner tube inserted in the second outer tube, the second inner tube and the second outer tube can move relative to each other, and a second threaded hole is provided on the second inner tube; a second adjusting member screwed into the second threaded hole, and the second adjusting member is embedded in the second groove, thereby achieving the fixation of the second inner tube and the second outer tube.

4. The oil and gas pipeline nondestructive testing device according to claim 1, characterized in that: The top of the excitation probe is provided with an excitation coil, and the outside of the excitation coil is provided with a shielding layer; the top of the detection probe is provided with a detection coil, and the outside of the detection coil is provided with a shielding layer.

5. The oil and gas pipeline nondestructive testing device according to claim 1, characterized in that: The oil and gas pipeline nondestructive testing device also includes: Main control panel; A D / A conversion module electrically connected to the main control panel, an amplifier circuit module electrically connected to the D / A conversion module, and an excitation coil of the excitation probe electrically connected to the amplifier circuit module; A differential circuit module electrically connected to the detection coil of the detection probe, an A / D conversion module electrically connected to the differential circuit module, and the main control panel electrically connected to the A / D conversion module.

6. The oil and gas pipeline nondestructive testing device according to claim 4, characterized in that: The excitation coil has a rectangular coil structure; the detection coil has a rectangular coil structure.

7. The oil and gas pipeline nondestructive testing device according to claim 6, characterized in that: The parameters of the rectangular coil are as follows: length 70 mm, width 20 mm, height 16 mm, thickness 5 mm, conductivity 5.8×10 7 S×m -1 , the relative magnetic permeability is 1.

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