Magnetostrictive guided wave transducer and guided wave monitoring system

Abstract

The utility model provides a magnetostriction guided wave transducer and guided wave monitoring system, magnetostriction guided wave transducer includes magnetostriction material, coil and magnet array, magnetostriction material is bent into the cylinder shape, magnet array includes a plurality of magnets that are arranged along the axial direction and circumferential direction of cylindrical magnetostriction material at intervals, and the magnetostriction material is bent into the cylinder shape. Each magnet is polarized along the radial direction of the magnetostrictive material, and the magnetic pole directions of the adjacent magnets are opposite; the coil is arranged in a bent mode and comprises excitation parts and connecting parts connected with the excitation parts, the excitation parts extend in the axial direction of the magnetostrictive material, the multiple excitation parts are arranged in the circumferential direction of the magnetostrictive material at intervals, and the connecting parts enable any excitation part to be connected with the head end of the excitation part on the circumferential side of the excitation part. The magnet is connected with the excitation part tail end on the other side of the excitation part in the circumferential direction, so that the excitation parts are connected in series, and the magnet is attached to the side, away from the magnetostrictive material, of each excitation part. The vertical magnetic field is utilized to generate guided waves, so that the problems that the magnetostrictive material is difficult to magnetize and easy to demagnetize and the horizontal magnetic field is not uniformly distributed can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of non-destructive testing, in particular to a magnetostrictive guided wave transducer and a guided wave monitoring system. Background Art

[0002] In the petroleum and petrochemical industries, long-term operation of in-service industrial equipment can lead to pipeline corrosion and defects. Failure to promptly address these issues can easily lead to safety incidents, resulting in irreparable losses and harm. Using ultrasonic guided wave testing technology for defect detection and corrosion monitoring of in-service industrial equipment pipelines can promptly identify safety hazards, provide early warnings, and enable appropriate measures to prevent industrial accidents.

[0003] Electromagnetic ultrasonic transducers transfer energy to conductive specimens or ferromagnetic materials through electromagnetic field coupling, conveniently generating various modes of ultrasonic guided waves within the workpiece being tested. They are currently one of the most popular methods for generating ultrasonic guided waves. The operating principles of electromagnetic ultrasonic transducers primarily include the Lorentz force mechanism and the magnetostrictive mechanism.

[0004] The magnetostrictive mechanism is that an alternating current is passed through a coil, which induces an alternating magnetic field on the surface of the test piece. This alternating magnetic field causes magnetostrictive strain in the magnetic domains on the surface of the workpiece being measured, thereby stimulating the generation of ultrasonic waves.

[0005] The conversion efficiency of electromagnetic ultrasonic transducers based on magnetostrictive mechanism is greatly affected by the magnetostrictive coefficient of the workpiece being measured. Therefore, high magnetostrictive materials with high magnetostrictive coefficients are often used in engineering to generate ultrasonic guided waves. The basic structure is as follows: Figure 1 shown.

[0006] The engineering application steps are as follows: (1) Use a coupling agent to stick the high magnetostrictive material to the surface of the pipe to be tested; (2) Use a magnet to pre-magnetize the high magnetostrictive material to generate a horizontal magnetic field; (3) Wind a coil around the surface of the high magnetostrictive material; (4) Connect the coil to the excitation receiving and processing device to excite the transducer to generate ultrasonic waves and process the ultrasonic signals. After the test is completed, the coil and high magnetostrictive material are removed and the next point is measured.

[0007] With the development of advanced technologies and concepts such as smart factories and fully digital management, the demand for continuous online monitoring using waveguide technology is becoming more and more widespread. Traditional magnetostrictive waveguide transducers cannot meet the needs of online monitoring. The main reasons are as follows: (1) Traditional magnetostrictive waveguide transducers use pre-magnetization to generate a horizontal magnetic field in high magnetostrictive materials, which is easy to demagnetize over a long period of time and is not conducive to long-term online monitoring; (2) The use of permanent magnets can solve the demagnetization problem of high magnetostrictive materials, but it is easy to cause uneven distribution of the horizontal magnetic field; (3) The magnetic permeability of high magnetostrictive materials is much lower than the magnetic permeability of the measured pipeline material, resulting in the high magnetostrictive materials being difficult to magnetize under the horizontal magnetic field, and the horizontal magnetic field in the high magnetostrictive materials is difficult to obtain. (4) The horizontal magnetic field strength is easily affected by the thickness of the pipeline wall. In order to obtain the best horizontal magnetic field strength in high magnetostrictive materials, the transducer parameters must be designed for each pipeline wall thickness, which makes on-site engineering application very difficult. Therefore, the traditional magnetostrictive waveguide transducer structure is difficult to be effectively applied to online monitoring scenarios. Utility Model Content

[0008] The present utility model aims to provide a magnetostrictive guided wave transducer and a guided wave monitoring system. In the magnetostrictive guided wave transducer, the magnetization direction of the magnet is set to be radial to the magnetostrictive material. That is, the magnetostrictive guided wave transducer excites ultrasonic guided waves based on a vertical magnetic field rather than a horizontal magnetic field. This avoids the problems of magnetostrictive materials being difficult to magnetize, easily demagnetized, and having uneven horizontal magnetic field distribution, and is not affected by pipe wall thickness.

[0009] To achieve one of the aforementioned objectives of the utility model, one embodiment of the present utility model provides a magnetostrictive guided wave transducer comprising a magnetostrictive material, a coil, and a magnet array. The magnetostrictive material is bent into a cylindrical shape. The magnet array comprises a plurality of magnets spaced apart along the axial and circumferential directions of the cylindrical magnetostrictive material. Each magnet is polarized radially of the magnetostrictive material, and the magnetic poles of adjacent magnets are in opposite directions. The coil is bent and comprises an excitation portion and a connecting portion connected to the excitation portion. The excitation portions extend axially along the magnetostrictive material, and a plurality of excitation portions are spaced apart circumferentially along the magnetostrictive material. The connecting portions connect any excitation portion to a leading end of the excitation portion on one circumferential side of the excitation portion and to a trailing end of the excitation portion on the other circumferential side of the excitation portion, thereby connecting the plurality of excitation portions in series. The magnet is attached to a side of the excitation portion facing away from the magnetostrictive material.

[0010] As a further improvement to one embodiment of the present invention, the magnets spaced apart axially along the magnetostrictive material form a row of magnets, and the magnet array includes multiple rows of magnets; in a row of magnets, the center spacing between adjacent magnets in the axial direction of the magnetostrictive material is half a wavelength, where the wavelength is the wavelength of the guided wave generated by the magnetostrictive guided wave transducer.

[0011] As a further improvement of an embodiment of the present invention, two coils are provided, and two coil excitation parts are provided under any column of magnets, and the current flow direction of the coil excitation parts under each column of magnets is the same.

[0012] As a further improvement of an embodiment of the present invention, two coils are provided, and two adjacent excitation parts of one of the two coils are provided under any column of magnets, and the excitation parts under two adjacent columns of magnets come from different coils.

[0013] As a further improvement of one embodiment of the present invention, two coils are provided, and the excitation parts of the two coils are alternately arranged along the circumferential direction of the magnetostrictive material; two magnet arrays are also provided, one magnet array is attached to the excitation part of one of the coils, and the other magnet array is attached to the excitation part of the other coil.

[0014] As a further improvement of an embodiment of the present invention, in the axial direction of the magnetostrictive material, the same ends of the magnets on the adjacent excitation parts of the two coils are separated by a quarter wavelength, and the currents in the two coils have a 90° phase difference.

[0015] As a further improvement of an embodiment of the present invention, the number of the magnets in the axial direction of the magnetostrictive material is 1 to 10.

[0016] As a further improvement of an embodiment of the present invention, the magnetostrictive material is selected from nickel, iron-cobalt alloy, iron-gallium alloy or terbium-dysprosium-iron; the coil is wound by enameled wire or processed by PCB technology.

[0017] An embodiment of the present invention further provides a guided wave monitoring system, comprising a monitoring host, a server, a terminal and the aforementioned magnetostrictive guided wave transducer.

[0018] As a further improvement of one embodiment of the present invention, the monitoring host includes a signal generating circuit, a power amplifying circuit, a matching circuit, a receiving circuit, an AD acquisition circuit, a main controller, and a data transmission circuit, and the magnetostrictive waveguide transducer is arranged between the matching circuit and the receiving circuit.

[0019] One or more technical solutions provided by this utility model have at least the following technical effects or advantages:

[0020] The magnetostrictive waveguide transducer provided by the utility model attaches a magnet to the side of the coil facing away from the magnetostrictive material, and the magnetization direction of the magnet is set to be radial to the magnetostrictive material. The vertical magnetic field is used to generate guided waves, which can avoid the problems of the magnetostrictive material being difficult to magnetize, easy to demagnetize, and uneven horizontal magnetic field distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a traditional magnetostrictive guided wave transducer structure.

[0022] Figure 2 It is a structural schematic diagram of the magnetostrictive waveguide transducer in the first embodiment of the present utility model.

[0023] Figure 3 yes Figure 2 A partial expanded schematic diagram of the central coil and magnet array.

[0024] Figure 4 FIG. 4 is a partial expanded schematic diagram of the coil and magnet array in the second embodiment.

[0025] Figure 5 FIG. 4 is a partial expanded schematic diagram of the coil and magnet array in the third embodiment.

[0026] Figure 6 FIG. 4 is a partial expanded schematic diagram of the coil and magnet array in the fourth embodiment.

[0027] 1. Magnetostrictive material; 2. Coil; 21. Excitation part; 22. Connecting part; 3. Magnet array; 4. Pipeline. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] As used herein, terms such as "center," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" that indicate spatial relative positions are used for ease of explanation to describe the relationship of one element or feature relative to another element or feature as shown in the accompanying drawings. Spatially relative terms may be intended to encompass different orientations of the device in use or operation other than the orientation shown in the drawings.

[0030] For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0032] The present invention provides a magnetostrictive waveguide transducer. Figure 2 、 3 As shown, the device comprises a magnetostrictive material 1, a coil 2, and a magnet array 3. The magnetostrictive material 1 is bent into a cylindrical shape. The magnet array 3 includes multiple magnets spaced axially and circumferentially along the cylindrical magnetostrictive material 1. Each magnet is polarized radially along the magnetostrictive material 1, and the magnetic poles of adjacent magnets are in opposite directions. The coil 2 is bent and includes an excitation portion 21 and a connecting portion 22 connected to the excitation portion 21. The excitation portion 21 extends axially along the magnetostrictive material 1, and multiple excitation portions 21 are spaced circumferentially along the magnetostrictive material 1. The connecting portion 22 connects any excitation portion 21 to the leading end of the excitation portion 21 on one circumferential side of the excitation portion 21 and to the trailing end of the excitation portion 21 on the other circumferential side of the excitation portion 21, thereby connecting multiple excitation portions 21 in series. The magnets are attached to the side of the excitation portion 21 facing away from the magnetostrictive material 1. The leading end herein refers to one axial end of the cylindrical magnetostrictive material 1, and the trailing end refers to the end opposite the leading end. The upper direction is the radial outward direction of the magnetostrictive material 1 , and the lower direction is the radial direction toward the axis of the magnetostrictive material 1 .

[0033] The magnetostrictive guided wave transducer provided by this utility model is designed to achieve online monitoring of pipelines 4. In actual use, the magnetostrictive material 1 is bent into a cylindrical shape that matches the outer diameter of the pipeline 4 to conform to the pipeline 4. Each magnet in the magnet array 3 is polarized perpendicularly to the magnetostrictive material 1, utilizing a perpendicular magnetic field to generate guided waves, eliminating the need to consider the impact of horizontal magnetic fields on the magnetostrictive guided wave transducer of this utility model. Each magnet in the magnet array 3 cooperates with the coil 2 and magnetostrictive material 1 below it to excite guided waves. Multiple magnets can excite multiple guided waves, and the phase difference can be adjusted to superimpose the guided waves, increasing the amplitude of the acoustic wave.

[0034] The coil 2 is composed of one or more turns of conductive wire. Spatially, the coil 2 is divided into an excitation portion 21 arranged axially along the magnetostrictive material 1 and a connection portion 22 for connecting the excitation portion 21. The excitation portion 21 cooperates with the magnet to excite the waveguide. The connection portion 22 connects one end of the excitation portion 21 (referred to as the head end) to the head end of the excitation portion 21 on one side of the excitation portion 21 in the circumferential direction. Another connection portion 22 connects the other end of the excitation portion 21 (referred to as the tail end) to the tail end of the excitation portion 21 on the other side of the excitation portion 21. This allows multiple excitation portions 21 to be connected in series, resulting in an S-shaped distribution of the coil 2 on the surface of the magnetostrictive material 1.

[0035] Furthermore, the magnets spaced apart axially along the magnetostrictive material 1 constitute a row of magnets, and the magnet array 3 includes multiple rows of magnets. In a row of magnets, the center spacing between adjacent magnets in the axial direction of the magnetostrictive material 1 is half a wavelength, where the wavelength is the wavelength of the guided wave generated by the magnetostrictive guided wave transducer.

[0036] In each column of the magnet array 3, the center-to-center distance between adjacent magnets is set to half the target wavelength, and the target wavelength is achieved by controlling the frequency of the coil 2. Guided waves are generated beneath the magnets and propagate axially along the magnetostrictive material 1. Because the center-to-center distance between adjacent magnets in the same column is half a wavelength, the guided wave emitted by any magnet in any column has a phase difference of 180° by the time it reaches beneath its neighbor. This creates a superposition effect with the phase of the guided wave emitted by the neighboring magnet, amplifying the amplitude. The phase superposition of multiple magnets in the same column also enhances the amplitude of the guided wave.

[0037] Further, such as Figure 4 In the example, two coils 2 are provided. Each row of magnets has two excitation sections 21 for the coils 2, and the current flows in the same direction in the excitation sections 21 of the coils 2 under each row of magnets. The two coils 2 are connected to different excitation sources, forming a dual-channel configuration. Compared to a single coil 2 under each magnet, this dual-channel configuration reduces the impedance of each coil 2 to half that of a single channel, thereby doubling the current intensity and improving the signal-to-noise ratio. During reception, the two coils 2 are connected to two separate receiving circuits. The main controller described below performs an addition operation on the two echo signals, merging them into a single echo signal. This is one form of a dual-channel magnetostrictive guided wave transducer.

[0038] In some embodiments, as Figure 5 In the embodiment, two coils 2 are provided, and two adjacent excitation parts 21 of one of the two coils 2 are provided under any column of magnets, and the excitation parts 21 under two adjacent columns of magnets come from different coils 2 .

[0039] In some embodiments, as Figure 6In this embodiment, two coils 2 are provided, with the excitation portions 21 of the two coils 2 arranged alternately along the circumference of the magnetostrictive material 1. Two magnet arrays are also provided, with one magnet array 3 attached to the excitation portion 21 of one coil 2, and the other magnet array 3 attached to the excitation portion 21 of the other coil 2. In other words, considering the coils 2 and magnet array 3 as a single set, this embodiment provides two sets of coils 2 and magnet arrays 3, with the excitation portions 21 of the two coils 2 and the magnets attached thereto alternating along the circumference of the magnetostrictive material 1. This represents the second form of a dual-channel magnetostrictive guided wave transducer. During assembly, the two coils 2 are stacked radially along the magnetostrictive material 1, and the two magnet arrays 3 are then aligned with the two coils 2, respectively.

[0040] Furthermore, in the axial direction of the magnetostrictive material 1, the magnets on the same ends of the adjacent excitation sections 21 of the two coils 2 are separated by a quarter wavelength, and the currents in the two coils have a 90° phase difference. The spatial position difference of the two channels is a quarter wavelength, and the excitation signals of the two channels have a 90° phase difference. This allows the ultrasound on one side to generate constructive interference, increasing its amplitude, while the ultrasound signal on the other side generates destructive interference, decreasing its amplitude, thereby achieving unidirectional propagation of the guided wave.

[0041] In some embodiments, the number of magnets in the axial direction of the magnetostrictive material 1 is 1 to 10, that is, the number of magnets in each column is 1 to 10. A larger number can enhance the signal amplitude, but it also increases the cost. The number of magnets in each column can be selected to obtain a sufficiently large amplitude signal and control the cost.

[0042] Preferably, the magnetostrictive material 1 is selected from nickel, iron-cobalt alloy, iron-gallium alloy or terbium-dysprosium-iron; the coil 2 is wound by enameled wire or processed by PCB technology.

[0043] An embodiment of the present invention further provides a guided wave monitoring system, comprising a monitoring host, a server, a terminal and the aforementioned magnetostrictive guided wave transducer.

[0044] Among them, the monitoring host includes a signal generating circuit, a power amplifying circuit, a matching circuit, a receiving circuit, an AD acquisition circuit, a main controller, and a data transmission circuit. The magnetostrictive waveguide transducer is arranged between the matching circuit and the receiving circuit.

[0045] The signal generation circuit generates guided wave excitation signal pulses, which can be either square or sinusoidal. The power amplifier circuit amplifies the signal generated by the signal generation circuit, increasing the signal's voltage and current, driving the magnetostrictive guided wave transducer to generate high-intensity guided waves. A matching circuit, placed between the power amplifier circuit and the magnetostrictive guided wave transducer, provides impedance matching and improves transduction efficiency. The receiving circuit receives the guided wave echo signal and performs signal processing, including amplification and filtering. The analog-to-digital (Analog-to-Digital) acquisition circuit converts the processed echo signal from the receiving circuit into a digital signal. The main controller, the core of the monitoring host, controls the entire circuit. The main controller can be a standard single-chip microcontroller, a more powerful microprocessor, or an FPGA (Field Programmable Gate Array) chip. The main controller performs calculations on the echo signals collected by the Analog-to-Digital (Analog-to-Digital) acquisition circuit. For a dual-channel magnetostrictive guided wave transducer, the main controller is also responsible for fusing the received dual-channel echo signals to generate a single echo signal. The data transmission circuit sends the data calculated by the main controller to the server via wireless or wired transmission.

[0046] The server, which can be a cloud server or a local server, is used to acquire and process guided wave data from the monitoring host. The server can process guided wave data to perform functions such as defect identification, defect growth trend calculation, pipeline corrosion rate calculation, and pipeline remaining life prediction.

[0047] Terminals include computers, smartphones, and other devices. Operators can view guided wave waveform signals and processed guided wave data on the terminal. They can also manually identify defects and view defect size, location, growth trend, pipeline corrosion rate, and remaining pipeline life.

[0048] It should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation method can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0049] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A magnetostrictive guided wave transducer, characterized in that: The device comprises a magnetostrictive material, a coil, and a magnet array. The magnetostrictive material is bent into a cylindrical shape. The magnet array comprises a plurality of magnets spaced apart along the axial and circumferential directions of the cylindrical magnetostrictive material. Each magnet is polarized radially along the magnetostrictive material, and the magnetic poles of adjacent magnets are in opposite directions. The coil is bent and comprises an excitation portion and a connecting portion connected to the excitation portion. The excitation portion extends axially along the magnetostrictive material, and a plurality of excitation portions are spaced apart along the circumference of the magnetostrictive material. The connecting portion connects any excitation portion to the leading end of the excitation portion on one circumferential side of the excitation portion and to the trailing end of the excitation portion on the other circumferential side of the excitation portion, thereby connecting the plurality of excitation portions in series. The magnet is attached to the side of the excitation portion facing away from the magnetostrictive material.

2. The magnetostrictive guided wave transducer according to claim 1, wherein: The magnets spaced apart along the axial direction of the magnetostrictive material constitute a row of magnets, and the magnet array comprises a plurality of rows of magnets. In a row of magnets, the center spacing of adjacent magnets in the axial direction of the magnetostrictive material is half a wavelength, where the wavelength is the wavelength of the guided wave generated by the magnetostrictive guided wave transducer.

3. The magnetostrictive guided wave transducer according to claim 2, characterized in that: There are two coils, and two coil excitation parts are arranged under any column of magnets, and the currents of the coil excitation parts under each column of magnets flow in the same direction.

4. The magnetostrictive guided wave transducer according to claim 2, wherein: There are two coils, and two adjacent excitation parts of one of the two coils are arranged under any column of magnets, and the excitation parts under two adjacent columns of magnets come from different coils.

5. The magnetostrictive guided wave transducer according to claim 2, characterized in that: There are two coils, and the excitation parts of the two coils are alternately arranged along the circumference of the magnetostrictive material; there are also two magnet arrays, one magnet array is attached to the excitation part of one coil, and the other magnet array is attached to the excitation part of the other coil.

6. The magnetostrictive guided wave transducer according to claim 5, characterized in that: In the axial direction of the magnetostrictive material, the same ends of the magnets on the adjacent excitation parts of the two coils are separated by a quarter wavelength, and the currents in the two coils have a 90° phase difference.

7. The magnetostrictive guided wave transducer according to any one of claims 1 to 6, characterized in that: In the axial direction of the magnetostrictive material, the number of the magnets is 1 to 10.

8. The magnetostrictive guided wave transducer according to any one of claims 1 to 6, characterized in that: The magnetostrictive material is selected from nickel, iron-cobalt alloy, iron-gallium alloy or terbium-dysprosium-iron; the coil is wound by enameled wire or processed by PCB technology.

9. A guided wave monitoring system, characterized in that: The invention comprises a monitoring host, a server, a terminal and the magnetostrictive guided wave transducer according to any one of claims 1 to 8.

10. The guided wave monitoring system according to claim 5, characterized in that: The monitoring host includes a signal generating circuit, a power amplifying circuit, a matching circuit, a receiving circuit, an AD acquisition circuit, a main controller, and a data transmission circuit. The magnetostrictive waveguide transducer is arranged between the matching circuit and the receiving circuit.

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