Electromagnetic ultrasonic transducer and detection system for GIL pipeline thickness measurement

Abstract

The invention discloses an electromagnetic ultrasonic transducer for GIL pipeline thickness measurement and a detection system. The electromagnetic ultrasonic transducer comprises a magnet assembly and a transduction coil. The magnet assembly is used for applying a vertical bias magnetic field to the to-be-tested GIL pipeline; the transduction coil is arranged on the strong side of the bias magnetic field of the magnet assembly and located between the GIL pipelines to be detected, when pulse current is introduced into the transduction coil, eddy current opposite to the direction of the pulse current in the transduction coil is formed in the side wall of the GIL pipelines to be detected, and the eddy current interacts with the vertical bias magnetic field to excite ultrasonic waves; ultrasonic waves reflected back from the GIL pipeline to be detected are received; the wiring end of the transduction coil is used for providing pulse current for the transduction coil and transmitting ultrasonic echoes received by the transduction coil to a detection system so as to detect the thickness of the side wall of the GIL pipeline to be detected.

Description

Technical Field

[0001] The present invention relates to the technical field of nondestructive testing, and in particular to an electromagnetic ultrasonic transducer and a detection system for GIL pipeline thickness measurement. Background Art

[0002] As an important part of the basic industry, metal pipelines are the industrial guarantee of the petroleum, chemical, electric power, shipbuilding, and nuclear industries, and are of great significance to areas related to the national economy and people's livelihood. However, in actual use, due to severe working conditions, such as corrosive media, erosion, fatigue, creep, etc., pipelines fail, bringing more serious and extremely serious consequences of failure, and often resulting in casualties and property losses.

[0003] At the same time, industrial pipelines have the characteristics of high frequency of renewal, harsh service environment, and complex failure forms. They are prone to defects such as corrosion thinning, scaling, and perforation. Pipeline wall thickness inspection is one of the important indicators of pipeline reliability and is the focus of regular pipeline inspections. Ultrasonic testing, as an important detection method in non-destructive testing, is widely used in industrial production. Traditional ultrasonic testing uses piezoelectric sensors. The vibration of the piezoelectric chip drives the test piece to vibrate, thereby generating ultrasonic waves. It is impossible to detect stratified defects in pipes or plates and defects in materials with poor penetration ability. At the same time, piezoelectric sensors require coupling agents when in use, and the pipeline needs to be polished if necessary.

[0004] Electromagnetic ultrasonic technology has developed rapidly in recent years and has received great attention. It has many advantages such as no need for coupling, no need for polishing, high stability in repeated detection, and applicability to extreme high and low temperature detection. It has excellent application prospects. The electromagnetic ultrasonic transducer is the key core component of electromagnetic ultrasonic detection technology. Its performance directly determines the electromagnetic ultrasonic detection effect and accuracy. The main functional components of the electromagnetic ultrasonic transducer are magnets and coils. The magnet provides a bias magnetic field, and a high-frequency alternating current signal is passed through the coil to excite ultrasonic waves in the test piece, and the coil receives the detection echo signal.

[0005] Therefore, it is necessary to optimize the design of the transducer and further improve the performance of the electromagnetic ultrasonic transducer used for the detection of metal plates, pipes, etc. Therefore, the transducer based on ultrasonic shear waves needs to provide a static magnetic field with a high intensity and a direction perpendicular to the coil to improve the detection quality, which is of great significance to promote the development and application of electromagnetic ultrasonic detection technology. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present invention provides an electromagnetic ultrasonic transducer and a detection system for GIL pipeline thickness measurement, so as to optimize the electromagnetic ultrasonic transducer and improve the accuracy of GIL pipeline thickness detection.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] An electromagnetic ultrasonic transducer for GIL pipeline thickness measurement, comprising a magnet assembly and a transducer coil;

[0009] The magnet assembly includes a second magnet, and a first magnet and a third magnet respectively arranged on both sides of the second magnet in a width direction, the magnetic field directions of the first magnet and the third magnet are placed opposite to each other, the magnetic field direction of the second magnet is perpendicular to the magnetic field directions of the first magnet and the third magnet, and one side of the magnetic field direction of the second magnet is a strong side of the bias magnetic field of the magnet assembly;

[0010] The transducer coil is arranged on the strong bias magnetic field side of the magnet assembly, and a shielding material layer is provided between the transducer coil and the magnet assembly. The wiring terminals of the transducer coil are used as electrical connection terminals for the excitation current and the magnetic induction signal.

[0011] In the electromagnetic ultrasonic transducer solution for measuring the thickness of the GIL pipeline, preferably, the bias magnetic field strong side of the magnet assembly is an arc-shaped surface that matches the shape of the outer wall of the GIL pipeline to be measured.

[0012] In the electromagnetic ultrasonic transducer scheme for GIL pipeline thickness measurement, preferably, the transducer coil is a butterfly coil structure formed by winding a group of wires, including a first coil and a second coil arranged in parallel, the first coil and the second coil are both wound to form a ring-shaped runway coil structure, and the current winding directions in the ring-shaped runway coils of the first coil and the second coil are opposite.

[0013] In the electromagnetic ultrasonic transducer solution for measuring the thickness of the GIL pipeline, preferably, the first coil and the second coil of the transducer coil are arranged in parallel to form an arc surface that matches the shape of the outer side wall of the GIL pipeline to be measured.

[0014] Correspondingly, the present invention also provides a detection system for GIL pipeline thickness measurement, comprising the aforementioned electromagnetic ultrasonic transducer for GIL pipeline thickness measurement, and also comprising a detection control device; the detection control device is electrically connected to the wiring terminal of the transducer coil; the detection control device is used to excite the transducer coil of the electromagnetic ultrasonic transducer to emit ultrasonic waves to the side wall of the GIL pipeline to be measured, and collect the time difference between two ultrasonic echoes of the side wall of the GIL pipeline to be measured through the transducer coil, calculate the propagation speed of the ultrasonic wave in the GIL pipeline to be measured, and calculate the side wall thickness of the GIL pipeline to be measured based on the propagation speed.

[0015] In the detection system solution for measuring the thickness of the GIL pipeline, specifically, the detection control device measures and obtains the side wall thickness of the GIL pipeline to be measured in a specific manner as follows:

[0016] According to the Young's modulus of the GIL pipeline to be tested, the propagation speed of the ultrasonic wave in the GIL pipeline to be tested is calculated, and ultrasonic detection is performed on any detection position of the GIL pipeline to be tested, and the transducer coil is excited to transmit the ultrasonic wave to the GIL pipeline to be tested, and the ultrasonic echo received by the transducer coil is collected, wherein the received ultrasonic echo includes a primary echo in which the transmitted ultrasonic wave reaches the inner wall of the GIL pipeline to be tested and is reflected, and a secondary echo in which the transmitted ultrasonic wave reaches the outer wall of the GIL pipeline to be tested and is reflected. According to the time difference between the received primary echo and the secondary echo, and the calculated propagation speed of the ultrasonic wave in the GIL pipeline to be tested, the side wall thickness of the GIL pipeline to be tested is measured and obtained.

[0017] In the detection system scheme for measuring the thickness of the GIL pipeline, specifically, the propagation speed of the ultrasonic wave in the GIL pipeline to be measured is calculated according to the Young's modulus of the GIL pipeline to be measured and is calculated as follows:

[0018]

[0019] Wherein, v is the propagation velocity of ultrasonic wave in the GIL pipeline to be tested, E is the Young's modulus of the GIL pipeline to be tested, ρ is the material density of the GIL pipeline to be tested, and σ is the Poisson's ratio of the GIL pipeline to be tested.

[0020] In the detection system scheme for measuring the thickness of the GIL pipeline, specifically, the side wall thickness of the GIL pipeline to be measured is calculated according to the following formula:

[0021]

[0022] Where d is the side wall thickness of the GIL pipe to be tested, t n is the time difference between the received first echo and the second echo.

[0023] Compared with the prior art, the present invention has the following technical effects:

[0024] 1. The electromagnetic ultrasonic transducer of the present invention has a transducer coil arranged on the strong side of the bias magnetic field of the magnet assembly and located between the GIL pipeline to be tested; the transducer coil is used to form an eddy current in the side wall of the GIL pipeline to be tested in the opposite direction to the pulse current in the transducer coil when a pulse current is passed through the transducer coil, and the eddy current interacts with the vertical bias magnetic field to excite ultrasonic waves and receive ultrasonic waves reflected back from the GIL pipeline to be tested; the wiring terminal of the transducer coil is used to provide a pulse current to the transducer coil and transmit the ultrasonic echo received by the transducer coil to the detection system for detecting the side wall thickness of the GIL pipeline to be tested.

[0025] 2. In the electromagnetic ultrasonic transducer of the present invention, the first magnet, the second magnet and the third magnet in the magnet assembly form a Halbach magnetic array structure, which can enable the magnet assembly to form a vertical bias magnetic field with a relatively concentrated magnetic field strength on one side, and can effectively enhance the single-sided magnetic strength performance of the magnet assembly. This high-intensity vertical bias magnetic field is much larger than the magnetic field generated by a single magnet, thereby enabling the electromagnetic ultrasonic transducer to efficiently excite and receive ultrasonic waves in the GIL pipeline without the need for coupling agents and polishing.

[0026] 3. In the electromagnetic ultrasonic transducer of the present invention, the transducer coil can be designed as a butterfly coil structure formed by winding a group of wires, including a first coil and a second coil arranged in parallel, the first coil and the second coil are both wound to form a ring-shaped runway coil structure, and the current winding directions of the ring-shaped runway coils of the first coil and the second coil are opposite. The use of such a transducer coil structure design is more conducive to enhancing the electromagnetic induction performance of the transducer coil, thereby improving the excitation efficiency of ultrasonic waves.

[0027] 4. The detection system of the present invention calculates the propagation speed of ultrasonic waves in the GIL pipeline to be tested according to the Young's modulus of the GIL pipeline to be tested, performs ultrasonic detection on any detection position of the GIL pipeline to be tested, excites the transducer coil to transmit ultrasonic waves to the GIL pipeline to be tested, and collects ultrasonic echoes received by the transducer coil, wherein the received ultrasonic echoes include a primary echo of the transmitted ultrasonic wave reaching the inner wall of the GIL pipeline to be tested and reflected, and a secondary echo of the transmitted ultrasonic wave reaching the outer wall of the GIL pipeline to be tested and reflected, and the side wall thickness of the GIL pipeline to be tested is calculated according to the time difference between the received primary echo and the secondary echo, and the calculated propagation speed of the ultrasonic wave in the GIL pipeline to be tested. Thus, accurate and non-destructive measurement of the side wall thickness of the GIL pipeline is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the purpose, technical solution and advantages of the invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0029] Figure 1 An electromagnetic ultrasonic transducer for measuring the thickness of a GIL pipeline disclosed in the present invention;

[0030] Figure 2 Schematic diagram of a transducer coil according to an embodiment of the present invention.

[0031] Explanation of the reference numerals: 1 - first magnet; 2 - second magnet; 3 - third magnet; 4 - transducer coil; 41 - first coil; 42 - second coil; 5 - GIL pipeline to be tested; 6 - connection terminal of the transducer coil. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but only represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0033] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0034] like Figure 1 , which is a schematic structural diagram of an embodiment of the present invention, provides an electromagnetic ultrasonic transducer for GIL pipeline thickness measurement, which includes a magnet assembly and a transducer coil 4;

[0035] The magnet assembly includes a second magnet 2, and a first magnet 1 and a third magnet 3 respectively arranged on both sides of the second magnet 2 in the width direction. The magnetic field directions of the first magnet 1 and the third magnet 3 are oppositely placed, the magnetic field direction of the second magnet 2 is perpendicular to the magnetic field directions of the first magnet 1 and the third magnet 3, and one side of the magnetic field direction of the second magnet 2 is the bias magnetic field strong side of the magnet assembly, which is used to face the side wall of the GIL pipeline 5 to be tested, so that the magnet assembly forms a vertical bias magnetic field facing the side wall of the GIL pipeline 5 to be tested. The first magnet 1, the second magnet 2 and the third magnet 3 in the magnet assembly thus arranged form a Halbach magnetic array structure, which can enable the magnet assembly to form a vertical bias magnetic field with a relatively concentrated magnetic field strength on one side, and can effectively enhance the single-sided magnetic strength performance of the magnet assembly. This high-intensity vertical bias magnetic field is much greater than the magnetic field generated by a single magnet, so that the electromagnetic ultrasonic transducer can efficiently excite and receive ultrasonic waves in the GIL pipeline without coupling agent and polishing.

[0036] The transducer coil 4 is arranged on the bias magnetic field strong side of the magnet assembly, and a shielding material layer is provided between the transducer coil 4 and the magnet assembly. The terminal 6 of the transducer coil is used as an electrical connection terminal for the excitation current and the magnetic induction signal. Figure 1 In the figure, the shielding material layer between the transducer coil 4 and the magnetic assembly is not shown. In a specific application, the shielding material layer can be air, plastic, resin or non-conductive soft magnetic material, etc., in order to avoid direct contact between the transducer coil 4 and the magnetic assembly, and to avoid the excitation current applied to the transducer coil 4 or the magnetic induction signal sensed by the transducer coil from being electrically interfered by the magnetic assembly during the detection.

[0037] In the specific detection implementation, the transducer coil 4 of the electromagnetic ultrasonic transducer is arranged on the strong side of the bias magnetic field of the magnet assembly and is located between the GIL pipeline 5 to be tested; the transducer coil 4 is used to form an eddy current in the side wall of the GIL pipeline 5 to be tested in the opposite direction to the pulse current in the transducer coil 4 when a pulse current is passed through the transducer coil 4, and the eddy current interacts with the vertical bias magnetic field to excite ultrasonic waves and receive ultrasonic waves reflected back from the GIL pipeline 5 to be tested; the terminal 6 of the transducer coil is used to provide a pulse current to the transducer coil 4, and transmit the ultrasonic echo received by the transducer coil 4 to the detection system, so as to detect the side wall thickness of the GIL pipeline to be tested.

[0038] The technical principle is that when a pulse current is passed through the transducer coil 4, an eddy current is formed in the skin layer of the GIL pipeline 5 to be tested in the opposite direction to the current direction of the transducer coil 4. Under the action of the static magnetic field, the eddy current causes the surface particles of the GIL pipeline 5 to be tested to be acted upon by the Lorentz force, the magnetizing force and the magnetostrictive force, wherein the Lorentz force and the magnetizing force play a major role. In the GIL pipeline 5 to be tested, the magnetizing force and the tangential component of the Lorentz force reinforce each other, thereby facilitating the generation of ultrasonic shear waves; and, based on the inverse effect of the Lorentz force, ultrasonic waves generate ultrasonic echo signals during the propagation of the GIL pipeline 5 to be tested, including a primary echo when the emitted ultrasonic wave reaches the inner wall of the GIL pipeline 5 to be tested and is reflected, and a secondary echo when the emitted ultrasonic wave reaches the outer wall of the GIL pipeline 5 to be tested and is reflected. Subsequently, the two echo signals can be sensed and received by the transducer coil 4, and thus can be used to transmit to the detection system for detecting the side wall thickness of the GIL pipeline to be tested.

[0039] In the application implementation, the bias magnetic field strong side of the magnet assembly can be designed as a curved surface that matches the shape of the outer wall of the GIL pipeline 5 to be tested. Figure 1 As shown, the bottom surface of the magnet assembly of the Halbach magnetic array structure formed by the first magnet 1, the second magnet 2 and the third magnet 3 is the bias magnetic field strong side surface, and its arc surface design adapted to the outer wall shape of the GIL pipeline 5 to be tested enables the bias magnetic field strong side surface of the magnet assembly to better match the curved surface shape of the outer wall of the pipeline, which is beneficial to reduce external interference, thereby improving the efficiency of the magnetic field and the coupling efficiency of the ultrasonic wave.

[0040] As for the structural design of the energy conversion coil 4, as a preferred solution, Figure 2As shown, the transducer coil 4 can be designed as a butterfly coil structure formed by winding a group of wires, including a first coil 41 and a second coil 42 arranged in parallel, the first coil 41 and the second coil 42 are both wound to form a ring-shaped racetrack coil structure, and the current winding directions in the ring-shaped racetrack coils of the first coil 41 and the second coil 42 are opposite. The use of such a structural design of the transducer coil 4 is more conducive to enhancing the electromagnetic induction performance of the transducer coil 4, thereby improving the excitation efficiency of the ultrasonic wave. In addition, as Figure 1 As shown, when the bias magnetic field strong side of the magnet assembly is designed as a curved surface that matches the shape of the outer wall of the GIL pipeline 5 to be tested, the first coil and the second coil of the transducer coil can also be designed to be arranged in parallel to form a curved surface that matches the shape of the outer wall of the GIL pipeline to be tested. Such a design is conducive to ensuring that the transducer coil 4 has a better coupling efficiency between the enhanced magnetic field and the ultrasonic excitation, improving the generation and reception of ultrasonic waves, and enhancing the detection sensitivity.

[0041] Correspondingly, this embodiment is based on the above-mentioned electromagnetic ultrasonic transducer for GIL pipeline thickness measurement, and also provides a detection system for GIL pipeline thickness measurement, the system also includes a detection control device, the detection control device is electrically connected to the terminal 6 of the transducer coil; the detection control device is used to excite the transducer coil of the electromagnetic ultrasonic transducer to emit ultrasonic waves to the side wall of the GIL pipeline to be measured, and collect the time difference between two ultrasonic echoes of the side wall of the GIL pipeline to be measured through the transducer coil, calculate the propagation speed of the ultrasonic wave in the GIL pipeline 5 to be measured, and calculate the side wall thickness of the GIL pipeline 5 to be measured based on the propagation speed.

[0042] Specifically, the electromagnetic ultrasonic transducer is placed on the surface of the GIL pipeline 5 to be tested, and the magnetic lines of force are emitted from the N poles of the first magnet 1 and the third magnet 3 on both sides, and flow from the N pole of the second magnet 2 in the middle to the GIL pipeline 5 to be tested, forming a vertical bias magnetic field from top to bottom. The current source is a pulse current passed through the transducer coil 4, and an eddy current in the opposite direction to the pulse current is formed on the near surface of the GIL pipeline 5 to be tested. The interaction between the eddy current and the vertical bias magnetic field forms an ultrasonic shear wave, thereby realizing the excitation and reception of the ultrasonic shear wave in the GIL pipeline 5 to be tested, and the received signal is processed and analyzed by a signal amplifier and a signal processor, so that the echo signal of the ultrasonic shear wave can be detected, and finally the side wall thickness of the GIL pipeline 5 to be tested is calculated according to the return time of the echo signal.

[0043] In this embodiment, the specific method in which the detection control device measures and obtains the side wall thickness of the GIL pipeline 5 to be tested is:

[0044] According to the Young's modulus of the GIL pipeline 5 to be tested, the propagation speed of the ultrasonic wave in the GIL pipeline 5 to be tested is calculated, and the ultrasonic detection is performed on any detection position of the GIL pipeline 5 to be tested, and the transducer coil 4 is excited to transmit the ultrasonic wave to the GIL pipeline 5 to be tested, and the ultrasonic echo received by the transducer coil 4 is collected, wherein the received ultrasonic echo includes a primary echo in which the transmitted ultrasonic wave reaches the inner wall of the GIL pipeline 5 to be tested and is reflected, and a secondary echo in which the transmitted ultrasonic wave reaches the outer wall of the GIL pipeline 5 to be tested and is reflected, and the side wall thickness of the GIL pipeline 5 to be tested is measured and obtained according to the time difference between the received primary echo and the secondary echo, and the calculated propagation speed of the ultrasonic wave in the GIL pipeline 5 to be tested;

[0045] Wherein, according to the Young's modulus of the GIL pipeline 5 to be tested, the propagation speed of the ultrasonic wave in the GIL pipeline 5 to be tested is calculated according to the following formula:

[0046]

[0047] Wherein, v is the propagation velocity of the ultrasonic wave in the GIL pipeline 5 to be tested, E is the Young's modulus of the GIL pipeline 5 to be tested, ρ is the material density of the GIL pipeline 5 to be tested, and σ is the Poisson's ratio of the GIL pipeline 5 to be tested.

[0048] In the specific implementation, the material of the GIL pipe 5 to be tested is aluminum alloy as an example, and the Young's modulus of aluminum alloy is an inherent property of the material, which can usually be found in the material science manual or the data table provided by the material supplier. Young's modulus is a physical quantity that describes the ratio of stress to strain when the material is subjected to tensile or compressive stress, and is an important parameter of the mechanical properties of the material. Therefore, it can be calculated that the propagation speed of the ultrasonic wave in the aluminum alloy GIL pipe 5 to be tested is 2030m / s.

[0049] According to the calculated propagation velocity of the ultrasonic wave in the GIL pipeline 5 to be tested, the side wall thickness of the GIL pipeline 5 to be tested is measured, and the calculation formula is:

[0050]

[0051] Where, d is the side wall thickness of the GIL pipe 5 to be tested, t n is the time difference between the received primary echo and the secondary echo. Thus, accurate and non-destructive measurement of the GIL pipeline side wall thickness can be achieved.

[0052] In summary, the present invention arranges three magnets with different magnetic field directions according to the Halbach array magnetic field structure, fixes the transducer coil 4 under the magnet assembly, and makes the conductor part of the transducer coil 4 located directly under the magnet assembly, and connects the transducer coil 4-pole current source through the terminal 6 of the transducer coil. Through such an optimized design of the ultrasonic transducer, a high-intensity vertical bias magnetic field is generated, thereby significantly improving the efficiency of ultrasonic emission and reception. This optimized magnetic field distribution helps to improve the accuracy and consistency of detection, while improving the signal-to-noise ratio of the received signal and obtaining a clearer ultrasonic signal. In addition, the simplified structural design makes the transducer easier to manufacture and maintain, and the absence of a coupling agent further simplifies the detection process and reduces costs. At the same time, the flexibility and adaptability of the transducer are improved, so that it can adapt to different detection environments and requirements, including effective operation in extreme environments such as high temperature, high pressure, and corrosiveness, thereby having broad application prospects in the field of non-destructive testing.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described with reference to the preferred embodiments of the present invention, it should be understood by those skilled in the art that various changes may be made in form and details without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. An electromagnetic ultrasonic transducer for GIL pipeline thickness measurement, characterized in that: It includes a magnet assembly and a transducer coil; The magnet assembly includes a second magnet, and a first magnet and a third magnet respectively arranged on both sides of the second magnet in a width direction, the magnetic field directions of the first magnet and the third magnet are placed opposite to each other, the magnetic field direction of the second magnet is perpendicular to the magnetic field directions of the first magnet and the third magnet, and one side of the magnetic field direction of the second magnet is a strong side of the bias magnetic field of the magnet assembly; The transducer coil is arranged on the strong bias magnetic field side of the magnet assembly, and a shielding material layer is provided between the transducer coil and the magnet assembly. The wiring terminals of the transducer coil are used as electrical connection terminals for the excitation current and the magnetic induction signal.

2. The electromagnetic ultrasonic transducer for GIL pipeline thickness measurement according to claim 1, characterized in that: The bias magnetic field strong side of the magnet assembly is an arc-shaped surface that matches the shape of the outer wall of the GIL pipeline to be tested.

3. The electromagnetic ultrasonic transducer for GIL pipeline thickness measurement according to claim 1, characterized in that: The transducer coil is a butterfly coil structure formed by winding a group of wires, including a first coil and a second coil arranged in parallel, the first coil and the second coil are both wound to form a ring-shaped racetrack coil structure, and the current winding directions in the ring-shaped racetrack coils of the first coil and the second coil are opposite.

4. The electromagnetic ultrasonic transducer for GIL pipeline thickness measurement according to claim 3, characterized in that: The first coil and the second coil of the energy conversion coil are arranged in parallel to form an arc surface that matches the shape of the outer side wall of the GIL pipeline to be tested.

5. A detection system for GIL pipeline thickness measurement, characterized in that: It comprises an electromagnetic ultrasonic transducer for measuring the thickness of a GIL pipeline as claimed in any one of claims 1 to 4, and also comprises a detection control device; the detection control device is electrically connected to the terminal of the transducer coil; the detection control device is used to excite the transducer coil of the electromagnetic ultrasonic transducer to emit ultrasonic waves to the side wall of the GIL pipeline to be measured, and collect the time difference between two ultrasonic echoes of the side wall of the GIL pipeline to be measured through the transducer coil, calculate the propagation speed of the ultrasonic wave in the GIL pipeline to be measured, and calculate the side wall thickness of the GIL pipeline to be measured based on the propagation speed.

6. The detection system for GIL pipeline thickness measurement according to claim 5, characterized in that: The specific method for the detection control device to measure and obtain the side wall thickness of the GIL pipeline to be tested is: According to the Young's modulus of the GIL pipeline to be tested, the propagation speed of the ultrasonic wave in the GIL pipeline to be tested is calculated, and ultrasonic detection is performed on any detection position of the GIL pipeline to be tested, and the transducer coil is excited to transmit the ultrasonic wave to the GIL pipeline to be tested, and the ultrasonic echo received by the transducer coil is collected, wherein the received ultrasonic echo includes a primary echo in which the transmitted ultrasonic wave reaches the inner wall of the GIL pipeline to be tested and is reflected, and a secondary echo in which the transmitted ultrasonic wave reaches the outer wall of the GIL pipeline to be tested and is reflected. According to the time difference between the received primary echo and the secondary echo, and the calculated propagation speed of the ultrasonic wave in the GIL pipeline to be tested, the side wall thickness of the GIL pipeline to be tested is measured and obtained.

7. The detection system for GIL pipeline thickness measurement according to claim 6, characterized in that: According to the Young's modulus of the GIL pipeline to be tested, the propagation speed of the ultrasonic wave in the GIL pipeline to be tested is calculated as follows: Wherein, v is the propagation velocity of ultrasonic wave in the GIL pipeline to be tested, E is the Young's modulus of the GIL pipeline to be tested, ρ is the material density of the GIL pipeline to be tested, and σ is the Poisson's ratio of the GIL pipeline to be tested.

8. The detection system for GIL pipeline thickness measurement according to claim 6, characterized in that: The side wall thickness of the GIL pipeline to be tested is calculated according to the following formula: Where d is the side wall thickness of the GIL pipe to be tested, t n is the time difference between the received first echo and the second echo.

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