Remanence effect based steel pipe crack detection device, test and use method

Abstract

The present specification provides a steel pipeline crack detection device based on residual magnetism effect, a test and use method, comprising: a rack; a support frame, a clamp, an excitation module, a three-axis sliding module, a signal acquisition module and a control end, the control end is used for controlling the winch to rotate at a preset speed, driving the excitation module to magnetize the measured pipeline at a preset speed; also used for controlling the signal acquisition module to collect signals from the measured pipeline at a preset lift-off value; also used for controlling the demagnetization module to demagnetize the measured pipeline; realize the use of residual magnetism effect to collect different pipeline parameters, different magnetization speed, different collection lift-off value and different crack size corresponding multi-element residual magnetism function. According to the ferromagnetic pipeline crack off-line residual magnetism detection device, the type of crack can be analyzed and automatically scanned, the scanning area is large, the response speed is fast, the precision is high, and the operation is simple.

Description

Technical Field

[0001] This invention relates to the field of equipment manufacturing technology, and in particular to a steel pipe crack detection device, testing method and application method based on residual magnetism. Background Technology

[0002] Oil and gas pipelines, as the "lifeline" of energy transportation, are of great significance to ensuring energy security. To ensure the safe operation of oil and gas pipelines, regular and effective non-destructive testing is necessary, with internal pipeline inspection being a key technology in pipeline integrity management. Currently common internal inspection technologies include magnetic flux leakage (MF) internal inspection, eddy current internal inspection, ultrasonic internal inspection, and magnetic memory stress internal inspection. Among these, MF internal inspection has become one of the most mature and widely used technologies due to its high reliability and operability. However, for certain special parts of oil and gas pipelines, such as circumferential weld cracks, MF detectors struggle to achieve normal detection of MF signals. Based on the remanent magnetization effect generated after the pipeline is magnetized to magnetic saturation by a MF detector, a steel pipeline crack detection device, testing method, and medium based on the remanent magnetization effect are designed to achieve effective pipeline crack detection. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, the purpose of this specification is to provide a steel pipe crack detection device based on the residual magnetism effect, along with testing and usage methods, thereby solving the problem that there is no steel pipe crack detection device designed based on the residual magnetism effect in the prior art.

[0004] To solve the above-mentioned technical problems, the specific technical solution in this specification is as follows:

[0005] On the one hand, this specification provides a steel pipe crack detection device based on the remanent magnetization effect, comprising:

[0006] frame;

[0007] A support frame is fixed to the bottom of the machine frame. A sliding component is provided on the upper part of the support frame. A demagnetizing module in the shape of an annular cavity is fixedly connected to the sliding component. The sliding component drives the demagnetizing module to move left and right within the machine frame to demagnetize the pipe under test. The pipe under test has different cracks at different locations.

[0008] The frame is provided with clamps on the left and right sides, and the pipe to be tested is clamped in the annular shape of the demagnetizing module;

[0009] An excitation module is provided on the upper side of the pipe under test, with both ends connected to a belt. At least one winch drives the excitation module to magnetize the pipe under test in the left and right directions at a preset magnetization speed via the belt.

[0010] The three-axis sliding module is provided on the upper side of the frame, and a signal acquisition module is provided at the end of the three-axis sliding module, which drives the signal acquisition module to move in three axes on the pipe under test.

[0011] The signal acquisition module is used to acquire residual magnetic field data at each position of the pipeline under test after it has been magnetized by the excitation module.

[0012] The control terminal is used to control the winch to rotate at a preset speed, driving the excitation module to magnetize the pipe under test at a preset magnetization speed; it is also used to control the signal acquisition module to acquire signals from the pipe under test at a preset lift-off value; it is also used to control the demagnetization module to demagnetize the pipe under test; and it is also used to fit a multivariate remanent magnetization function based on the pipe parameters of the pipe under test, the rotation speed of the winch, the remanent magnetic field data, and the crack information corresponding to different cracks.

[0013] As one embodiment of this specification, the three-axis sliding module includes two slide rails, a planar moving rod, and a probe rod;

[0014] The two slide rails are arranged parallel to each other on the left and right sides of the frame. The extension direction of the planar moving rod is perpendicular to the extension direction of the two slide rails. The planar moving rod is movably connected to the two slide rails and moves back and forth on the two slide rails. The detection rod is movably connected to the planar moving rod. The movement direction of the detection rod is perpendicular to the movement direction of the planar moving rod. The end of the detection rod is provided with a signal acquisition module.

[0015] As one embodiment of this specification, the sliding assembly includes a slide rail, a drive motor, and a slider;

[0016] The slide rail is fixedly mounted on the upper part of the support frame, and the slider is fixedly mounted on the bottom of the demagnetizing module;

[0017] The drive motor drives the slider to move left and right within the slide rail.

[0018] As one embodiment of this specification, the sliding assembly includes a lead screw assembly, a drive motor, and a lead screw nut;

[0019] The lead screw assembly is fixedly mounted on the upper part of the support frame, and the lead screw nut is fixedly mounted on the bottom of the demagnetizing module. The drive motor drives the lead screw in the lead screw assembly to rotate, causing the lead screw nut to move left and right on the lead screw.

[0020] As one embodiment of this specification, the clamp is located at a position corresponding to the annular shape, and the clamp includes a pipe support clamp and a fixing clamp;

[0021] The pipe clamps are fixed to the left and right sides of the frame respectively. The recess of the pipe clamp fits against the pipe to be tested. The fixing clamp and the pipe clamp are fixed to the pipe to be tested by bolts.

[0022] As one embodiment of this specification, the signal acquisition module includes a sensor, an amplifier circuit, a filter circuit, and an analog-to-digital converter circuit;

[0023] The sensor is used to collect residual magnetic field data at each location of the pipe under test and convert it into an analog signal;

[0024] The amplifier circuit is used to amplify the analog signal and send it to the filter circuit;

[0025] The filtering circuit is used to filter the analog signal and send it to the analog-to-digital conversion circuit;

[0026] The analog-to-digital converter circuit is used to convert analog signals into digital signals, wherein the digital signals are used to fit the multivariate remanence function.

[0027] As one embodiment of this specification, the excitation module includes a permanent magnet, an iron core, and steel brushes;

[0028] The iron core is wrapped around the permanent magnet, and the two ends of the iron core are connected to the belt. The steel brush is sleeved on the outside of the iron core and contacts the upper side of the pipe being tested.

[0029] The permanent magnet is made of N45 neodymium iron boron, the iron core is made of 1J22 soft magnet, and the steel brush is made of manganese steel.

[0030] On the other hand, this specification also provides a test method using any of the detection devices described in the claims, comprising:

[0031] The pipe under test with different cracks is placed in the fixture, and the winch is controlled by the control terminal to drive the excitation module to magnetize the pipe under test at a preset speed.

[0032] Use the control terminal to fix the signal acquisition module at a preset distance on the pipe under test and start the acquisition mode of the signal acquisition module.

[0033] The control terminal is used to control the three-axis sliding module to drive the signal acquisition module to acquire residual magnetic field data at each position of the pipe under test;

[0034] The control terminal displays and stores the residual magnetic field data, and closes the acquisition mode of the signal acquisition module after the acquisition is completed.

[0035] The control terminal fits a multivariate remanence function corresponding to the preset lift-off value and preset magnetization velocity based on the preset acquisition lift-off value, preset magnetization velocity, acquired magnetic field data, and different crack sizes.

[0036] As one embodiment of this specification, after the control terminal fits a multivariate remanence function corresponding to the preset lift-off value and preset velocity based on the preset acquisition lift-off value, preset magnetization velocity, acquired magnetic field data, and different crack sizes, the process includes:

[0037] The signal acquisition module and the excitation module are reset using the control terminal.

[0038] The control terminal is used to control the demagnetization module to demagnetize the tested pipeline;

[0039] Returning to the next step: Place the manually processed pipe under test into the fixture, and use the control terminal to control the winch to drive the excitation module to magnetize the pipe under test at a preset speed, thereby obtaining several multivariate remanent functions corresponding to different lift-off values ​​and different preset magnetization speeds.

[0040] On the other hand, this specification also provides a method for using the multivariate remanence function obtained using the aforementioned test method, including:

[0041] Based on the magnetization velocity of the excitation module on the steel pipe and the distance between the signal acquisition module and the steel pipe, select the corresponding multivariate remanence function;

[0042] The control unit imports the magnetic field data of each location of the steel pipe collected by the signal acquisition module into the multivariate remanent magnetization function to obtain the crack size information of each location of the steel pipe.

[0043] Using the above technical solution, the frame can support and protect the various components; the support frame is fixed to the bottom of the main frame, and a sliding component is provided on the upper part of the support frame. A demagnetizing module with an annular shape is fixedly connected to the sliding component. The sliding component drives the demagnetizing module to move left and right within the frame to demagnetize the pipe under test, thus achieving demagnetization of the tested pipe after testing; the clamps are provided on the left and right sides of the main frame, and the pipe under test passes through the annular shape of the demagnetizing module and is clamped in the clamps, thus fixing the pipe under test inside the main frame and preventing it from falling due to winch vibration during testing; the excitation module is provided on the upper side of the pipe under test, with both ends connected to belts. At least one winch drives the excitation module to magnetize the pipe under test in a left-right direction at a preset magnetization speed via the belt, thus achieving excitation of all positions of the pipe under test; the frame... The upper side is equipped with the three-axis sliding module, and the end of the three-axis sliding module is equipped with a signal acquisition module, which drives the signal acquisition module to move along the three axes on the pipe under test, so as to realize the acquisition of residual magnetism at all positions of the pipe under test. The signal acquisition module is used to collect the residual magnetic field data at each position of the pipe under test after being magnetized by the excitation module, so as to obtain the residual magnetic field data at each position. The residual magnetic field data is the data generated after remagnetization. The control terminal is used to control the rotation speed of the winch and the preset lift-off value of the signal acquisition module. It is also used to control the demagnetization module to demagnetize the pipe under test. It is also used to fit a multivariate residual magnetism function based on the pipe parameters of the pipe under test, the rotation speed of the winch and the residual magnetic field data. Different rotation speeds of the winch can be used to pull the excitation module to excite the pipe under test, and the preset lift-off value can be used to collect the residual magnetic field data at each position of the pipe under test, and then multiple multivariate residual magnetism functions can be obtained by fitting them sequentially.

[0044] To make the above and other objects, features and advantages of this specification more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 A schematic diagram of a steel pipe crack detection device based on the residual magnetism effect is shown in an embodiment of this specification;

[0047] Figure 2 A schematic diagram of the excitation module in an embodiment of this specification is shown;

[0048] Figure 3 A schematic diagram of the three-axis sliding module according to an embodiment of this specification is shown;

[0049] Figure 4 A first schematic diagram of the sliding component according to an embodiment of this specification is shown;

[0050] Figure 5 The flowchart of the residual magnetic field detection experimental circuit of the embodiment of this specification is shown;

[0051] Figure 6 This specification illustrates a step diagram of a testing method using the detection device according to an embodiment of the present specification;

[0052] Figure 7 A schematic diagram of a computer device according to an embodiment of this specification is shown.

[0053] Explanation of symbols in the attached drawings:

[0054] 1. Rack;

[0055] 2. Support frame;

[0056] 21. Sliding component;

[0057] 22. Slide rail;

[0058] 23. Slider;

[0059] 3. Demagnetization module;

[0060] 4. Fixtures;

[0061] 5. Excitation module;

[0062] 6. Winch;

[0063] 7. Three-axis sliding module;

[0064] 71. Slide rack;

[0065] 72. Planar moving rod;

[0066] 73. Detector rod;

[0067] 8. Signal acquisition module;

[0068] 702. Computer equipment;

[0069] 704, Processor;

[0070] 706. Memory;

[0071] 708. Drive mechanism;

[0072] 710. Input / Output Module;

[0073] 712. Input devices;

[0074] 714. Output devices;

[0075] 716. Presentation equipment;

[0076] 717. Graphical User Interface;

[0077] 720. Network interface;

[0078] 722. Communication link;

[0079] 724. Communication bus. Detailed Implementation

[0080] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this specification.

[0081] It should be noted that the terms "first," "second," etc., used in this specification, claims, and the foregoing drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0082] like Figure 1 The schematic diagram shown is of a steel pipe crack detection device based on the remanent magnetization effect, including:

[0083] Frame 1; In this specification, frame 1 is the largest component and can be welded from multiple steel pipes or multiple triangular irons to protect and fix the components. The specific welding shape is not limited in this specification. The space formed by frame 1 needs to accommodate at least two winches 6, support frame 2, excitation module 5 and demagnetization module 3.

[0084] A support frame 2 is fixed to the bottom of the frame 1. A sliding assembly 21 is provided on the upper part of the support frame 2. A ring-shaped demagnetizing module 3 is fixedly connected to the sliding assembly 21. The sliding assembly 21 drives the demagnetizing module 3 to move left and right within the frame 1 to demagnetize the tested pipe. In this specification, the support frame 2 is placed inside the frame 1. Because the demagnetizing module 3 is relatively large, the support frame 2 is needed to hold the demagnetizing module 3, allowing it to move from one side to the other within the frame 1. For ease of explanation, the left side of the frame 1 can be considered the initial position of the demagnetizing module 3. The demagnetizing module 3 moves from the left to the right side of the frame 1 to demagnetize the tested pipe. After demagnetization, the demagnetizing module 3 moves from the right to the left side of the frame 1 to reset the tested pipe. In this specification, to facilitate the demagnetizing module 3 to perform omnidirectional demagnetization of the tested pipe, the demagnetizing module 3 can be designed in an "U" shape. The tested pipe passes through the annular shape of the demagnetizing module 3 and is fixed to the clamp 4, thus securing the tested pipe. Preferably, the bottom of the support frame 2 is provided with support feet, which are used to increase the contact area between the support frame 2 and the ground.

[0085] The clamps 4 are provided on the left and right sides of the frame 1. The pipe under test passes through the annular shape of the demagnetizing module 3 and is clamped in the clamps 4. To facilitate the excitation and demagnetization of the pipe under test and to prevent it from falling and damaging other components due to vibration, clamps 4 are designed inside the frame 1. In this specification, the fixed position of the clamps 4 is on the same horizontal line as the annular position of the pipe under test. In this specification, the clamps 4 can be part of the frame 1 and integrally formed. Similarly, the clamps 4 can also be welded to the frame 1. This specification does not limit the formation process of the clamps 4. In this specification, the demagnetizing module 3 is set in the space formed by the clamps 4 on both sides. When fixing the pipe under test, the pipe under test passes through the demagnetizing module 3 and is then fixed on the clamps 4.

[0086] The pipe clamps 41 are fixed to the left and right sides of the frame 1 respectively.

[0087] The demagnetizing module 3 consists of a wound coil. The changes in the direction and magnitude of the current and magnetic field are "commutated and attenuated simultaneously". When the tested pipe is placed in an alternating amplitude that gradually decreases, the trajectory of the hysteresis loop also becomes smaller and smaller. When the magnetic field strength drops to zero, the residual magnetism in the workpiece is close to zero, thus achieving the demagnetizing effect. In this manual, demagnetization must be performed after each magnetization experiment before proceeding to the next experiment.

[0088] like Figure 2The diagram shows an excitation module 5. The excitation module 5, with both ends connected to belts, is located on the upper side of the pipe under test. At least one winch 6 drives the excitation module 5 via a belt to magnetize the pipe under test in a left-right direction. In this specification, to ensure the excitation effect of the excitation module 5, it is typically driven by a belt. After the pipe under test is fixed, the excitation module 5 is placed on the pipe to excite it. This method maximizes excitation at all points on the pipe under test.

[0089] Preferably, the excitation module 5 includes a permanent magnet, an iron core, and steel brushes;

[0090] The iron core is sleeved on the outside of the permanent magnet, and the two ends of the iron core are connected to the belt. The steel brush is sleeved on the outside of the iron core and contacts the upper side of the pipe being tested.

[0091] The permanent magnet is made of N45 neodymium iron boron, the iron core is made of 1J22 soft magnet, and the steel brush is made of manganese steel.

[0092] The three-axis sliding module 7 is provided on the upper side of the frame 1. The end of the three-axis sliding module 7 is provided with a signal acquisition module 8, which drives the signal acquisition module 8 to move in three axes on the pipe under test.

[0093] like Figure 3 The schematic diagram of the three-axis sliding module shown is provided. The three-axis sliding module 7 includes two slide rails 71, a planar moving rod 72, and a probe rod 73.

[0094] The two slide rails 71 are arranged parallel to each other on the left and right sides of the frame 1. The extension direction of the planar moving rod 72 is perpendicular to the extension direction of the two slide rails 71. The planar moving rod 72 is movably connected to the two slide rails 71 and moves back and forth on the two slide rails 71. The detection rod 73 is movably connected to the planar moving rod 72. The movement direction of the detection rod 73 is perpendicular to the movement direction of the planar moving rod 72. The end of the detection rod 73 is provided with a signal acquisition module 8. In this way, when the detection rod 73 moves left and right on the planar moving rod 72, the signal acquisition module 8 moves in space along the X-axis; when the planar moving rod 72 moves back and forth on the slide rails 71, the signal acquisition module 8 moves in space along the Y-axis; and when the detection rod 73 moves up and down on the planar moving rod 72, the signal acquisition module 8 moves in space along the Z-axis, thereby achieving three-axis sliding of the signal acquisition module 8.

[0095] The signal acquisition module 8 is used to acquire the residual magnetic field data at each position of the pipeline under test after it has been magnetized by the excitation module 5. In this specification, the signal acquisition module 8 mainly uses a sensor to convert the magnetic flux into an analog signal, processes it, and then sends it to the control terminal (not shown).

[0096] The control terminal is used to control the winch 6 to rotate at a preset speed, thereby driving the excitation module 5 to magnetize the pipe under test at a preset speed; it is also used to control the signal acquisition module 8 to acquire signals from the pipe under test at a preset distance from the pipe under test; it is also used to control the demagnetization module 3 to demagnetize the pipe under test; and it is also used to acquire multivariate remanent magnetization functions corresponding to different pipe parameters, different magnetization speeds, different acquisition lift-off values, and different crack sizes using the remanent magnetization effect.

[0097] Using the above technical solution, the frame 1 can support and protect the various components; the support frame 2 is fixed to the bottom of the frame 1, and the upper part of the support frame 2 is provided with a sliding component 21. A ring-shaped demagnetizing module 3 is fixedly connected to the sliding component 21. The sliding component 21 drives the demagnetizing module 3 to move left and right within the frame 1 to demagnetize the pipe under test, thus achieving demagnetization of the pipe after testing; the clamps 4 are provided on the left and right sides of the frame 1. The test pipe is clamped in the annular shape of the demagnetizing module 3 through the fixture 4, which can fix the test pipe inside the frame 1 and prevent it from falling due to the vibration of the winch 6 during testing; through the excitation module 5, the test pipe is provided with the excitation module 5 at both ends connected to the belt, and at least one winch 6 drives the excitation module 5 to magnetize the test pipe in the left and right direction through the belt, which can realize the excitation of all positions of the test pipe; through the three-axis sliding module 7, the... The frame 1 is equipped with a three-axis sliding module 7, and a signal acquisition module 8 is located at the end of the three-axis sliding module 7. The signal acquisition module 8 is driven to move along three axes on the pipe under test, which can realize the acquisition of residual magnetism at all positions of the pipe under test. The signal acquisition module 8 is used to acquire the residual magnetic field data at each position of the pipe under test after it has been magnetized by the excitation module 5. The residual magnetic field data is generated after remagnetization. The control terminal is used to control the rotation speed of the winch 6 and the acquisition position of the signal acquisition module 8. It is also used to control the demagnetization module 3 to demagnetize the pipe under test. It is also used to fit a multivariate remanent magnetization function based on the pipe parameters of the pipe under test, the rotation speed of the winch 6 and the residual magnetic field data. Different rotation speeds of the winch 6 can be used to pull the excitation module 5 to excite the pipe under test, and a fixed lift-off value can be used to acquire the residual magnetic field data at each position of the pipe under test. Then, multiple multivariate remanent magnetization functions can be obtained by fitting them sequentially.

[0098] like Figure 4 The first schematic diagram of the sliding component shown includes a slide rail 22, a drive motor (not shown), and a slider 23.

[0099] The slide rail 22 is fixedly mounted on the upper part of the support frame 2, and the slider 23 is fixedly mounted on the bottom of the demagnetizing module 3;

[0100] The drive motor drives the slider 23 to move left and right within the slide rail 22.

[0101] As one embodiment of this specification, the sliding assembly 21 further includes a lead screw assembly, a drive motor, and a lead screw nut;

[0102] The lead screw assembly is fixedly mounted on the upper part of the support frame 2, and the lead screw nut is fixedly mounted on the bottom of the demagnetizing module 3. The drive motor drives the lead screw in the lead screw assembly to rotate, causing the lead screw nut to move left and right on the lead screw.

[0103] The signal acquisition module 8 includes a sensor, an amplifier circuit, a filter circuit, and an analog-to-digital converter circuit;

[0104] The sensor is used to collect residual magnetic field data at each location of the pipe under test and convert it into an analog signal; in this specification, the sensor is a Hall sensor, which has the function of converting residual magnetic signals into Hall electromotive force.

[0105] The amplifier circuit is used to amplify the analog signal and send it to the filter circuit. The amplifier circuit adopts a two-stage amplification with an adjustable amplification factor of 2 to 40 times. It is built using LM358 and OP07 chips. The LM358 contains two independent, high-gain, internally frequency-compensated dual operational amplifiers, while the OP07 chip is a low-noise bipolar operational amplifier with extremely low input offset voltage.

[0106] The filtering circuit is used to filter the analog signal and send it to the analog-to-digital conversion circuit; it consists of a current-limiting resistor and a pull-up resistor.

[0107] The analog-to-digital converter circuit is used to convert analog signals into digital signals, wherein the digital signals are used to fit the multivariate remanent magnetization function. In this specification, an oscilloscope can be connected after the pull-up resistor to perform analog-to-digital conversion to obtain digital signals, and then the control terminal performs data analysis to obtain remanent magnetization induction signal data information.

[0108] like Figure 5 The flowchart of the residual magnetic field detection experimental circuit shown illustrates how a permanent magnet is used to relatively uniformly magnetize a pipe, causing localized changes in the magnetic field near pipe defects. Multiple simulations using Comsol software demonstrate that the required magnetic field to saturate pipes with different wall thicknesses varies. After magnetization, the residual magnetism effect at pipe defects is measured. Artificial defects are created in the pipe, and the residual magnetism components at different defect locations are detected. The permanent magnet excites the pipe, generating a magnetized region. The residual magnetism signal is acquired and processed by signal acquisition module 8, and the data is analyzed and displayed by the control unit.

[0109] There is no existing technology for detecting cracks in steel pipes based on the residual magnetism effect.

[0110] To address the aforementioned problems, the embodiments in this specification provide a testing method capable of detecting cracks in steel pipes using the remanent magnetization effect. Figure 6This is a schematic diagram illustrating the steps of a testing method using the aforementioned detection device, as provided in an embodiment of this specification. This specification provides the operational steps of the method described in the embodiments or flowcharts, but based on conventional or non-inventive labor, more or fewer operational steps may be included. The order of steps listed in the embodiments is merely one possible execution order among many and does not represent the only possible execution order. In actual system or device products, the methods shown in the embodiments or drawings can be executed sequentially or in parallel. Specifically, as shown in the attached diagrams... Figure 6 As shown, the method may include:

[0111] Step 601: Place the pipe under test with different cracks into the fixture, and use the control terminal to control the winch to drive the excitation module to magnetize the pipe under test at a preset speed.

[0112] Step 602: Use the control terminal to fix the signal acquisition module on the pipe under test at a preset distance and start the acquisition mode of the signal acquisition module;

[0113] Step 603: Use the control terminal to control the three-axis sliding module to drive the signal acquisition module to acquire residual magnetic field data at each position of the pipe under test;

[0114] Step 604: The control terminal displays and stores the residual magnetic field data, and after the acquisition is completed, turns off the acquisition mode of the signal acquisition module;

[0115] Step 605: The control terminal fits a multivariate remanence function corresponding to the preset lift-off value and the preset magnetization speed based on the preset acquisition lift-off value, the preset magnetization speed, the acquired magnetic field data and different crack sizes.

[0116] The above method can be used to obtain several multivariate remanence functions corresponding to different lift-off values ​​and preset speeds, which can then be used to calculate the crack size on the pipe corresponding to different remanence values.

[0117] As one embodiment of this specification, after the control terminal fits a multivariate remanence function corresponding to the preset lift-off value and preset velocity based on the preset acquisition lift-off value, preset magnetization velocity, acquired magnetic field data, and different crack sizes, the process includes:

[0118] The signal acquisition module and the excitation module are reset using the control terminal.

[0119] The control terminal is used to control the demagnetization module to demagnetize the tested pipeline;

[0120] Returning to the next step: Place the manually processed pipe under test into the fixture, and use the control terminal to control the winch to drive the excitation module to magnetize the pipe under test at a preset speed, thereby obtaining several multivariate remanent functions corresponding to different lift-off values ​​and different preset magnetization speeds.

[0121] Specifically, let's take the detection of a pipeline defect as an example:

[0122] A crack defect measuring 10mm in length, 1mm in width, and 4mm in depth is machined on the inner wall of the tested pipe with an opening of φ273*6mm. The pipe is then placed on a pipe clamp, and the positions of the excitation module, signal acquisition module, and demagnetization module are checked to ensure that they are in their initial positions and that all connections are normal.

[0123] Turn on the power to the winch, and use a belt to pull the excitation module from one end of the pipe to the other at a speed of 0.2 m / s to saturate the pipe. Then turn off the power to the winch.

[0124] Turn on the power to the three-axis sliding module, and adjust the Z-axis position of the signal acquisition module through the control terminal so that the lift-off value between the signal acquisition module and the pipe under test is 2mm. Turn on the probe acquisition mode through the control terminal and adjust the sampling frequency to 500Hz. At this time, observe whether the data displayed on the control terminal is normal. If there is no problem, proceed to the next step.

[0125] The control terminal controls the signal acquisition module to scan the X-axis at a speed of 0.2 m / s directly above the defect, acquiring the residual magnetic signal at the defect in the tested pipeline in real time. The detected residual magnetic field data is then displayed and stored in real time through the control terminal. After the scan is completed, the acquisition mode of the signal acquisition module is turned off.

[0126] The signal acquisition module and excitation module are reset, and the magnetized test pipe is demagnetized by the demagnetization module to prepare for the next set of experiments. At the same time, the detected data is noted and organized.

[0127] After completing the above steps, the residual magnetic field signal of a 10mm long * 1mm wide * 4mm deep crack after saturation magnetization is acquired and stored under the conditions of a lift-off value of 2mm and an acquisition speed of 0.2m / s. This signal can then be used to fit a multivariate remanent magnetization function.

[0128] Repeated testing enables the acquisition and storage of residual magnetism signals from different pipeline defects under different lift-off values ​​and acquisition speeds, as well as the fitting of multivariate residual magnetism functions.

[0129] On the other hand, this specification also provides a method for using the multivariate remanence function obtained by the test method, including:

[0130] Based on the magnetization velocity of the excitation module on the steel pipe and the distance between the signal acquisition module and the steel pipe, select the corresponding multivariate remanence function;

[0131] The control unit imports the magnetic field data of each location of the steel pipe collected by the signal acquisition module into the multivariate remanent magnetization function to obtain the crack size information of each location of the steel pipe.

[0132] like Figure 7 As shown, a computer device 702 provided in an embodiment of this specification is used to execute the test methods described herein. The computer device 702 may include one or more processors 704, such as one or more central processing units (CPUs), each of which may implement one or more hardware threads. The computer device 702 may also include any memory 706 for storing information of any kind, such as code, settings, data, etc. Without limitation, for example, the memory 706 may include any type of RAM, any type of ROM, flash memory, hard disk, optical disk, etc. More generally, any memory can use any technology to store information. Further, any memory may provide volatile or non-volatile retention of information. Further, any memory may represent a fixed or removable component of the computer device 702. In one case, when the processor 704 executes associated instructions stored in any memory or combination of memories, the computer device 702 may perform any operation of the associated instructions. The computer device 702 also includes one or more drive mechanisms 708 for interacting with any memory, such as hard disk drive mechanisms, optical disk drive mechanisms, etc.

[0133] Computer device 702 may also include an input / output module 710 (I / O) for receiving various inputs (via input device 712) and providing various outputs (via output device 714). A specific output mechanism may include a presentation device 718 and an associated graphical user interface (GUI) 718. In other embodiments, the input / output module 710 (I / O), input device 712, and output device 714 may be omitted, and the device may function solely as a computer device within a network. Computer device 702 may also include one or more network interfaces 720 for exchanging data with other devices via one or more communication links 722. One or more communication buses 724 couple the components described above together.

[0134] Communication link 722 can be implemented in any way, such as via a local area network, a wide area network (e.g., the Internet), a point-to-point connection, or any combination thereof. Communication link 722 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc., governed by any protocol or combination of protocols.

[0135] Corresponding to Figure 6 In addition to the methods described above, embodiments of this specification also provide a computer-readable storage medium storing a computer program that, when executed by a processor, performs the steps of the methods described above.

[0136] This specification also provides computer-readable instructions, wherein when a processor executes the instructions, the program therein causes the processor to perform the following... Figure 6 The method shown.

[0137] It should be understood that in the various embodiments of this specification, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this specification.

[0138] It should also be understood that, in the embodiments of this specification, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this specification generally indicates that the preceding and following related objects have an "or" relationship.

[0139] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this specification can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this specification.

[0140] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0141] In the several embodiments provided in this specification, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, devices, or units, or they may be electrical, mechanical, or other forms of connection.

[0142] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments described in this specification, depending on actual needs.

[0143] Furthermore, the functional units in the various embodiments of this specification can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0144] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this specification, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this specification. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0145] This specification uses specific embodiments to illustrate the principles and implementation methods of this specification. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this specification. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this specification. Therefore, the content of this specification should not be construed as a limitation of this specification.

Claims

1. A steel pipe crack detection device based on remanent magnetization, characterized in that, include: frame; A support frame is fixed to the bottom of the machine frame. A sliding component is provided on the upper part of the support frame. A demagnetizing module in the shape of an annular cavity is fixedly connected to the sliding component. The sliding component drives the demagnetizing module to move left and right within the machine frame to demagnetize the pipe under test. The pipe under test has different cracks at different locations. The frame is provided with clamps on the left and right sides, and the pipe to be tested is clamped in the annular shape of the demagnetizing module; An excitation module is provided on the upper side of the pipe under test, with both ends connected to a belt. At least one winch drives the excitation module to magnetize the pipe under test in the left and right directions at a preset magnetization speed via the belt. The three-axis sliding module is provided on the upper side of the frame, and a signal acquisition module is provided at the end of the three-axis sliding module, which drives the signal acquisition module to move in three axes on the pipe under test. The signal acquisition module is used to acquire residual magnetic field data at each position of the pipeline under test after it has been magnetized by the excitation module. The control terminal is used to control the winch to rotate at a preset speed, driving the excitation module to magnetize the pipe under test at a preset magnetization speed; it is also used to control the signal acquisition module to acquire signals from the pipe under test at a preset lift-off value; it is also used to control the demagnetization module to demagnetize the pipe under test; and it is also used to fit a multivariate remanent magnetization function based on the pipe parameters of the pipe under test, the rotation speed of the winch, the remanent magnetic field data, and the crack information corresponding to different cracks.

2. The steel pipe crack detection device based on remanent magnetization effect according to claim 1, characterized in that, The three-axis sliding module includes two slide rails, a planar moving rod, and a detection rod; The two slide rails are arranged parallel to each other on the left and right sides of the frame. The extension direction of the planar moving rod is perpendicular to the extension direction of the two slide rails. The planar moving rod is movably connected to the two slide rails and moves back and forth on the two slide rails. The detection rod is movably connected to the planar moving rod. The movement direction of the detection rod is perpendicular to the movement direction of the planar moving rod. The end of the detection rod is provided with a signal acquisition module.

3. The steel pipe crack detection device based on remanent magnetization effect according to claim 1, characterized in that, The sliding assembly includes a slide rail, a drive motor, and a slider; The slide rail is fixedly mounted on the upper part of the support frame, and the slider is fixedly mounted on the bottom of the demagnetizing module; The drive motor drives the slider to move left and right within the slide rail.

4. The steel pipe crack detection device based on remanent magnetization effect according to claim 1, characterized in that, The sliding assembly includes a lead screw assembly, a drive motor, and a lead screw nut; The lead screw assembly is fixedly mounted on the upper part of the support frame, and the lead screw nut is fixedly mounted on the bottom of the demagnetizing module. The drive motor drives the lead screw in the lead screw assembly to rotate, causing the lead screw nut to move left and right on the lead screw.

5. The steel pipe crack detection device based on remanent magnetization effect according to claim 1, characterized in that, The clamp is positioned corresponding to the annular shape, and the clamp includes a pipe support clamp and a fixing clamp; The pipe clamps are fixed to the left and right sides of the frame respectively. The recess of the pipe clamp fits against the pipe to be tested. The fixing clamp and the pipe clamp are fixed to the pipe to be tested by bolts.

6. The steel pipe crack detection device based on remanent magnetization effect according to claim 1, characterized in that, The signal acquisition module includes a sensor, an amplifier circuit, a filter circuit, and an analog-to-digital converter circuit; The sensor is used to collect residual magnetic field data at each location of the pipe under test and convert it into an analog signal; The amplifier circuit is used to amplify the analog signal and send it to the filter circuit; The filtering circuit is used to filter the analog signal and send it to the analog-to-digital conversion circuit; The analog-to-digital converter circuit is used to convert analog signals into digital signals, wherein the digital signals are used to fit the multivariate remanence function.

7. The steel pipe crack detection device based on remanent magnetization effect according to claim 1, characterized in that, The excitation module includes a permanent magnet, an iron core, and steel brushes; The iron core is wrapped around the permanent magnet, and the two ends of the iron core are connected to the belt. The steel brush is sleeved on the outside of the iron core and contacts the upper side of the pipe being tested. The permanent magnet is made of N45 neodymium iron boron, the iron core is made of 1J22 soft magnet, and the steel brush is made of manganese steel.

8. A testing method using the detection apparatus according to any one of claims 1-7, characterized in that, include: The pipe under test with different cracks is placed in the fixture, and the winch is controlled by the control terminal to drive the excitation module to magnetize the pipe under test at a preset speed. Use the control terminal to fix the signal acquisition module at a preset distance on the pipe under test and start the acquisition mode of the signal acquisition module. The control terminal is used to control the three-axis sliding module to drive the signal acquisition module to acquire residual magnetic field data at each position of the pipe under test; The control terminal displays and stores the residual magnetic field data, and closes the acquisition mode of the signal acquisition module after the acquisition is completed. The control terminal fits a multivariate remanence function corresponding to the preset lift-off value and preset magnetization velocity based on the preset acquisition lift-off value, preset magnetization velocity, acquired magnetic field data, and different crack sizes.

9. The test method according to claim 8, characterized in that, After the control terminal obtains a multivariate remanence function corresponding to the preset lift-off value and preset velocity based on the preset acquisition lift-off value, preset magnetization velocity, acquired magnetic field data, and different crack sizes, the process includes: The signal acquisition module and the excitation module are reset using the control terminal. The control terminal is used to control the demagnetization module to demagnetize the tested pipeline; Returning to the next step: Place the manually processed pipe under test into the fixture, and use the control terminal to control the winch to drive the excitation module to magnetize the pipe under test at a preset speed, thereby obtaining several multivariate remanent functions corresponding to different lift-off values ​​and different preset magnetization speeds.

10. A method for using the multivariate remanence function obtained by the test method according to claim 8 or 9, characterized in that, include: Based on the magnetization velocity of the excitation module on the steel pipe and the distance between the signal acquisition module and the steel pipe, select the corresponding multivariate remanence function; The control unit imports the magnetic field data of each location of the steel pipe collected by the signal acquisition module into the multivariate remanent magnetization function to obtain the crack size information of each location of the steel pipe.

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