CN118311154A - Electromagnetic ultrasonic guided wave sensor for high temperature pipeline defect detection - Google Patents

Abstract

The invention relates to the technical field of sensors, in particular to an electromagnetic ultrasonic guided wave sensor for detecting defects of a high-temperature pipeline. The invention aims to provide an electromagnetic ultrasonic guided wave sensor for detecting defects of a high-temperature pipeline, which comprises a cooling structure and an electromagnetic ultrasonic guided wave sensor body, wherein the cooling structure comprises a double-layer cooling shell, a water inlet connecting pipe, a water outlet connecting pipe, an intermediate heat insulation layer and an elastic bottom heat insulation layer, one end of the water inlet connecting pipe is communicated with an inner barrel body, the other end of the water inlet connecting pipe is exposed out of the double-layer cooling shell, one end of the water outlet connecting pipe is communicated with the inner barrel body, and the other end of the water outlet connecting pipe is exposed out of the double-layer cooling shell. Through ingenious cooling structure's design for this sensor can detect high temperature pipeline, makes the sensor bottom can adapt to the camber on high temperature pipeline surface simultaneously for thermal-insulated basement through adopting the fire prevention cloth basement, improves the detection efficiency of sensor, is convenient for effectively detect the defect of different diameter high temperature pipelines.

Description

Electromagnetic ultrasonic guided wave sensor for high temperature pipeline defect detection

Technical Field

The present invention relates to the field of sensor technology, and in particular to an electromagnetic ultrasonic guided wave sensor, specifically an electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection.

Background technique

High-temperature metal pipelines (hereinafter referred to as high-temperature pipelines) are widely used in the petroleum, chemical, electric power and other industries. When high-temperature pipelines are in the harsh working conditions of transporting high-temperature and high-pressure liquids or gases for a long time, the stress generated by the internal high-temperature fluid and the stress generated by the external supporting structure often cause defects such as pitting corrosion on the pipe wall. If the defect is not discovered in time, the defect will be further expanded, resulting in perforation or rupture of the pipe wall, thereby causing the leakage of toxic or flammable and explosive media, causing significant losses of people's lives and property.

The electromagnetic ultrasonic detection technology in the existing technology is currently an ideal pipeline defect detection technology because it has the advantages of not requiring coupling agents, not requiring surface polishing, and being easy to excite various sound wave modes. Electromagnetic ultrasonic detection technology is divided into two types: electromagnetic ultrasonic body wave detection technology and electromagnetic ultrasonic guided wave detection technology. The electromagnetic ultrasonic body wave sensor used for high-temperature pipelines uses a point scanning detection method when detecting defects. During the detection, it is necessary to strip off all the coating layers on the high-temperature pipeline to be tested and detect point by point, which is time-consuming and laborious; at the same time, for pipelines with many supporting and shielding parts under actual working conditions, it is difficult to use electromagnetic ultrasonic body wave sensors to implement pipeline defect detection because it is impossible to approach these parts.

Although electromagnetic ultrasonic guided wave sensors can detect defects in pipelines with many supporting and shielding parts, and only a small part of the coating needs to be peeled off during detection to achieve full detection of the pipeline around or within a certain length, with high detection efficiency and reduced preparation time, existing electromagnetic ultrasonic guided wave sensors are currently unable to realize defect detection on high-temperature pipelines, that is, there are currently no electromagnetic ultrasonic guided wave sensors for high-temperature pipeline defect detection.

Summary of the invention

The object of the present invention is to provide an electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection.

The present invention is achieved by adopting the following technical solutions:

An electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection, comprising a cooling structure and an electromagnetic ultrasonic guided wave sensor body;

The cooling structure includes a double-layer cooling shell, a water inlet pipe, and a water outlet pipe. The double-layer cooling shell includes an inner barrel body and an outer barrel body. The middle part of the barrel bottom of the inner barrel body protrudes toward the inner barrel body cavity so that a cooling groove is formed in the middle part of the barrel bottom. The barrel bottom of the outer barrel body is a fireproof cloth base. An insulation cavity is arranged between the inner barrel body and the outer barrel body. The top of the insulation cavity is sealed. The top of the inner barrel body is sealed. One end of the water inlet pipe is connected to the inner barrel body, and the other end of the water inlet pipe is exposed to the double-layer cooling shell. One end of the water outlet pipe is connected to the inner barrel body, and the other end of the water outlet pipe is exposed to the double-layer cooling shell.

The electromagnetic ultrasonic guided wave sensor body includes a plurality of array element sensors, each of which includes a runway-shaped coil and two groups of array permanent magnets pressed on the upper part of the runway-shaped coil and adapted to the runway-shaped coil. Each two groups of array permanent magnets are arranged side by side along the transverse direction of the runway-shaped coil, and each group of array permanent magnets includes a plurality of magnetic blocks arranged side by side along the longitudinal direction of the runway-shaped coil. The plurality of runway-shaped coils are arranged side by side in a straight line along the transverse direction of the runway-shaped coil and are interconnected to form a T-mode transmitting coil or an SH-wave transmitting coil (it is well known to those skilled in the art that during detection, when axial defect detection of a high-temperature pipeline is performed, the longitudinal direction of the plurality of runway-shaped coils is consistent with the axial direction of the high-temperature pipeline, and the plurality of runway-shaped coils are interconnected to form a T-mode transmitting coil or an SH-wave transmitting coil). Modal transmitting coil, when performing circumferential defect detection on a high-temperature pipeline, the longitudinal direction of the multiple runway-shaped coils is consistent with the circumferential direction of the high-temperature pipeline, then the multiple runway-shaped coils are interconnected to form an SH wave transmitting coil), the multiple groups of array permanent magnets are all located in the cooling groove of the inner barrel body, and the top surface and four side surfaces of the multiple groups of array permanent magnets are respectively fitted with the four groove walls and groove bottom of the cooling groove, an elastic bottom insulation layer is provided between the multiple groups of array permanent magnets and the multiple runway-shaped coils, and the elastic bottom insulation layer is fixed outside the cooling groove, the upper surfaces of the multiple runway-shaped coils are fixed to the bottom surface of the elastic bottom insulation layer, the ports of the multiple runway-shaped coils after interconnection pass through the insulation cavity and are exposed to the double-layer cooling shell, and the lower surfaces of the multiple runway-shaped coils are in contact with the middle of the base of the fireproof cloth.

Furthermore, the number of array element sensors is two or three. When the diameter of the high-temperature pipeline is large, three array element sensors are suitable, and the detection effect is obvious. For the content of this part, see the patent application with the publication number CN117266263A, and the patent name is the patent application of narrow beam electromagnetic ultrasonic sensor and device for pipeline axial defect detection; when the diameter of the high-temperature pipeline is not large, two array element sensors are suitable, and relatively effective detection can be achieved while ensuring a reasonable size structure.

Furthermore, a plurality of racetrack-shaped coils are fixed to the bottom surface of the elastic bottom insulation layer by high-temperature glue to prevent the racetrack-shaped coils from melting and short-circuiting when the temperature of the high-temperature pipeline is too high, thereby further improving the effectiveness of high-temperature pipeline defect detection.

Furthermore, the insulation cavity is filled with an intermediate insulation layer. During testing, the bottom of the outer barrel body is in contact with the high temperature, so the temperature of the outer barrel body rises, which will then radiate heat to the inner barrel body, thereby affecting the cooling effect. However, due to the presence of the intermediate insulation layer, most of the heat on the outer barrel body is prevented from being transferred to the inner barrel body to a certain extent, thereby improving the cooling effect of the inner barrel body.

Furthermore, the top of the heat-insulating cavity and the inner barrel body are sealed by a cover plate, and a handle is fixed on the cover plate, which is convenient for placing the sensor on the high-temperature pipe during detection and for lifting the sensor after the detection is completed.

Furthermore, the handle is located on the part of the cover corresponding to the middle insulation layer. The handle is a hollow handle. The port after the multiple runway-shaped coils are interconnected is provided with a BNC connector. The BNC connector passes through the middle insulation layer and then comes out from the hollow handle, which is convenient for connection with the electromagnetic detector. At the same time, the middle insulation layer is used to provide high-temperature protection for the BNC connector to prevent high-temperature melting and deformation from causing short circuit.

Furthermore, the cooling structure also includes two groups of spring compression and stretching mechanisms, both of which are arranged in the middle insulation layer, and the two groups of spring compression and stretching mechanisms are symmetrically arranged on both sides of the transverse direction or longitudinal direction of the multiple runway-shaped coils (when performing axial defect detection on the high-temperature pipeline, the longitudinal direction of the multiple runway-shaped coils is consistent with the axial direction of the high-temperature pipeline. At this time, the two groups of spring compression and stretching mechanisms are symmetrically arranged on both sides of the transverse direction of the multiple runway-shaped coils. When performing circumferential defect detection, the longitudinal direction of the multiple runway-shaped coils is consistent with the circumferential direction of the high-temperature pipeline. At this time, the two groups of spring compression and stretching mechanisms are symmetrically arranged on both sides of the longitudinal direction of the multiple runway-shaped coils), each group of spring compression and stretching mechanisms includes at least one spring stretching member, and each spring stretching member includes a connector, a screw, a vertical A straight column, a top plate, a spring cavity, a magnet, and a spring. A connecting head is vertically fixed to the corresponding position of the cover plate, and the top end of the connecting head is located above the cover plate, and the bottom end of the connecting head is located below the cover plate. An internal threaded hole compatible with the screw is provided on the connecting head, and the screw is threadedly connected to the internal threaded hole on the connecting head. The top sleeve of the spring cavity is fixed to the bottom end of the connecting head, and the top plate is vertically fixed to the top of the vertical column. The vertical column and the top plate are both placed in the spring cavity, and the top plate is located below the connecting head. The bottom end of the vertical column is exposed at the bottom of the spring cavity, and a limiting ring is coaxially fixed on the inner wall of the bottom end of the spring cavity. The spring slides up and down on the vertical column and is located between the upper surface of the limiting ring and the top plate. The bottom end of the vertical column is hinged with a magnet and the axial direction of the hinge axis is parallel to the axial direction of the high-temperature pipeline. When in use, the screw is turned, and the screw moves downward to push the top plate, the vertical column and the magnet downward. At this time, the spring is compressed, and when the magnet moves down close to the outer wall of the high-temperature pipe, due to the suction force of the magnet, the magnet is adsorbed to the outer wall of the high-temperature pipe through the fireproof cloth base, thereby stretching the fireproof cloth base, making the fireproof cloth base fit more closely to the outer wall of the high-temperature pipe, thereby making the curvature adaptability of the sensor to the high-temperature pipe higher and improving its detection accuracy. When the detection is completed, the sensor is separated from the pipe, and the screw is turned in the opposite direction to move the screw upward. The spring recovers upward and pushes the top plate upward, and the top plate moves upward to drive the vertical column upward, so that the fireproof cloth base is restored to its original state for the next use.

Furthermore, the bottom surface of the magnet is an inclined surface adapted to the circumference of the high-temperature pipeline, which further improves the curvature adaptability of the sensor and the high-temperature pipeline.

Furthermore, each set of spring compression and stretching mechanisms includes two spring stretching members evenly distributed along the axial direction of the high-temperature pipeline, and the structure is standardized and rationalized, which improves the stability of the detection. The bottom end of the connector is provided with an external thread, and the top end of the spring cavity is provided with an internal thread, which facilitates the connection between the spring cavity and the connector, and is easy to install and disassemble.

The beneficial effects produced by the present invention are as follows:

1) The electromagnetic ultrasonic guided wave sensor provided by the present invention can be used for high-temperature pipeline defect detection through the design of an ingenious cooling structure. At the same time, by using a fireproof cloth substrate as a heat-insulating substrate, the bottom of the sensor can adapt to the curvature of the surface of high-temperature pipelines with different diameters, thereby improving the detection efficiency of the sensor and facilitating effective detection of defects in high-temperature pipelines;

2) The electromagnetic ultrasonic guided wave sensor provided by the present invention has a wide range of application occasions and has low requirements on the surface of high-temperature pipelines and low requirements on the spatial conditions of high-temperature pipelines. That is, during detection, only a small part of the coating of the high-temperature pipeline needs to be peeled off to detect a certain area of the pipeline without polishing. In addition, defects in high-temperature pipelines with many supporting and shielding parts under actual working conditions can also be effectively detected.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

Fig. 1 is a schematic diagram of the overall structure of the present invention;

FIG2 is an exploded schematic diagram of FIG1 ;

FIG3 is a schematic diagram of the overall structure after removing the outer barrel;

FIG4 is a schematic structural diagram of a spring tension member;

FIG5 is a schematic structural diagram of an inner barrel;

FIG6 is a schematic diagram of the assembly structure of the inner barrel and the array permanent magnet;

FIG7 is a schematic diagram of the assembly structure of the inner barrel and the electromagnetic ultrasonic guided wave sensor body;

FIG8 is a schematic diagram of the assembly structure of the inner barrel body, the electromagnetic ultrasonic guided wave sensor body, and the outer barrel body without the barrel bottom;

FIG9 is a schematic structural diagram of the spring compression and stretching mechanism assembled in FIG8;

FIG10 is a schematic diagram of the structure of FIG9 with the middle heat insulation layer assembled;

FIG11 is a schematic diagram of the electromagnetic ultrasonic guided wave sensor described in the present invention in use when performing circumferential defect detection on a high-temperature pipeline across a support;

FIG12 is a time domain signal diagram of an electromagnetic ultrasonic circumferential waveguide sensor for high-temperature pipeline cross-support defect detection using a ceramic plate substrate as a heat-insulating substrate;

FIG13 is a time domain signal diagram of an electromagnetic ultrasonic circumferential waveguide sensor for high-temperature pipeline cross-support defect detection using a fireproof cloth substrate as a heat-insulating substrate as described in the present invention;

FIG. 14 is a time domain signal diagram of a 630° C. high-temperature pipeline spanning a support for continuous detection for 10 minutes using the sensor described in the present invention.

In the figure: 1-inner barrel, 2-outer barrel, 3-cooling groove, 4-fireproof cloth base, 5-insulation cavity, 6-water inlet pipe, 7-water outlet pipe, 8-runway type coil, 9-array permanent magnet, 10-elastic bottom insulation layer, 11-high temperature pipeline, 12-middle insulation layer, 13-cover plate, 14-hollow handle, 15-spring tension member, 151-connector, 152-screw, 153-vertical column, 154-top plate, 155-spring, 156-magnet, 157-spring cavity tube, 158-limiting ring, 161-direct wave, 162-defect echo, 163-primary echo.

Detailed ways

In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

In the description, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

As shown in Figs. 1, 2, 3, 5, 6, 7 and 8, an electromagnetic ultrasonic guided wave sensor for high temperature pipeline defect detection includes a cooling structure and an electromagnetic ultrasonic guided wave sensor body;

The cooling structure includes a double-layer cooling shell, a water inlet pipe 6, and a water outlet pipe 7. The double-layer cooling shell includes an inner barrel body 1 and an outer barrel body 2. The middle part of the bottom of the inner barrel body 1 protrudes toward the inner cavity of the barrel body so that a cooling groove 3 is formed in the middle part of the bottom of the barrel. The bottom of the outer barrel body 2 is a fireproof cloth base 4. An insulation cavity 5 is provided between the inner barrel body 1 and the outer barrel body 2. The top of the insulation cavity 5 is sealed, and the top of the inner barrel body 1 is sealed. One end of the water inlet pipe 6 is connected to the inner barrel body 1, and the other end of the water inlet pipe 6 is exposed to the double-layer cooling shell. One end of the water outlet pipe 7 is connected to the inner barrel body 1, and the other end of the water outlet pipe 7 is exposed to the double-layer cooling shell.

The electromagnetic ultrasonic guided wave sensor body includes a plurality of array element sensors, each of which includes a runway-shaped coil 8 and two groups of array permanent magnets 9 pressed on the upper part of the runway-shaped coil 8 and adapted to the runway-shaped coil 8. Each two groups of array permanent magnets 9 are arranged side by side along the transverse direction of the runway-shaped coil 8, and each group of array permanent magnets 9 includes a plurality of magnetic blocks arranged side by side along the longitudinal direction of the runway-shaped coil 8. The plurality of runway-shaped coils 8 are arranged side by side in a straight line along the transverse direction of the runway-shaped coil 8 and are interconnected to form a T-mode transmitting coil or an SH-wave transmitting coil (it is well known to those skilled in the art that during detection, when the axial defect detection of the high-temperature pipeline 11 is performed, the longitudinal direction of the plurality of runway-shaped coils 8 is consistent with the axial direction of the high-temperature pipeline 11, then the plurality of runway-shaped coils 8 are interconnected to form a T-mode transmitting coil. When the circumferential defect detection of the high-temperature pipeline 11 is carried out, the longitudinal direction of the multiple runway-shaped coils 8 is consistent with the circumferential direction of the high-temperature pipeline 11, then the multiple runway-shaped coils 8 are interconnected to form an SH wave transmitting coil), the multiple groups of array permanent magnets 9 are all located in the cooling groove 3 of the inner barrel body 1, and the top surface and four side surfaces of the multiple groups of array permanent magnets 9 are respectively in contact with the four groove walls and groove bottom of the cooling groove 3, an elastic bottom insulation layer 10 is provided between the multiple groups of array permanent magnets 9 and the multiple runway-shaped coils 8, and the elastic bottom insulation layer 10 is fixed outside the cooling groove 3, the upper surfaces of the multiple runway-shaped coils 8 are fixed to the bottom surface of the elastic bottom insulation layer 10, the ports of the multiple runway-shaped coils 8 after interconnection pass through the insulation cavity 5 and are exposed to the double-layer cooling shell, and the lower surfaces of the multiple runway-shaped coils 8 are in contact with the middle of the fireproof cloth base 4.

Instructions for use: Before testing, prepare two sensors as described above and an electromagnetic ultrasonic detector and a host computer adapted to the sensors, connect the water inlet pipe 6 and the water outlet pipe 7 to the water pump, and adsorb the two sensors in a straight line along the circumference of the high-temperature pipeline 11 to a certain position on the outer wall of the high-temperature pipeline 11, and the longitudinal direction of the racetrack-shaped coils 8 in the two sensors is consistent with the circumferential or axial direction of the high-temperature pipeline 11 (when the axial defect detection of the high-temperature pipeline 11 is performed, the longitudinal direction of multiple racetrack-shaped coils 8 is consistent with the axial direction of the high-temperature pipeline 11, and when the circumferential defect detection of the high-temperature pipeline 11 is performed, the longitudinal direction of multiple racetrack-shaped coils 8 is consistent with the axial direction of the high-temperature pipeline 11. The circumferential direction of the temperature pipe 11 is consistent), one of the sensors is used as an electromagnetic ultrasonic guided wave excitation sensor, the electromagnetic ultrasonic guided wave excitation sensor is connected to the excitation port of the electromagnetic ultrasonic detector, and the other sensor is used as an electromagnetic ultrasonic guided wave receiving sensor, the electromagnetic ultrasonic guided wave receiving sensor is connected to the receiving port of the electromagnetic ultrasonic detector, and the communication port of the electromagnetic ultrasonic detector is connected to the host computer, and the host computer is used to send command signals to the electromagnetic ultrasonic detector (the command signal is parameters such as excitation frequency, excitation period, excitation voltage, and receiving gain) and receive and store digital signals sent by the electromagnetic ultrasonic detector and convert the digital signals into time domain signal graphs.

During the inspection, turn on the water pump to allow cooling water to continuously flow into the inner barrel body 1 from the water inlet pipe 6 and leave the inner barrel body 1 from the water outlet pipe 7; the electromagnetic ultrasonic detector excites the electromagnetic ultrasonic guided wave excitation sensor to generate SH waves in the high-temperature pipe 11, and then the electromagnetic ultrasonic guided wave receiving sensor receives the detection echo, which is amplified and filtered by the electromagnetic ultrasonic detector and discretized into a digital signal. The digital signal is then transmitted to the host computer, and the host computer converts the digital signal into a time domain signal graph, and the defect information of the axial detection or circumferential detection is judged by the time domain signal graph. After the axial or circumferential defect detection corresponding to the position is completed, the two sensors are then translated circumferentially or axially to another position, and the axial or circumferential defects corresponding to the position are detected until the circumferential detection of the high-temperature pipe 11 including all defects blocked by the support bracket is completed. This detection method can relatively accurately and quickly determine the axial or circumferential position of the defect on the high-temperature pipe 11.

Principle description: multiple groups of array permanent magnets 9 are placed in the cooling groove 3 of the inner barrel 1, and the top surface and four side surfaces of the multiple groups of array permanent magnets 9 are respectively in contact with the four groove walls and groove bottom of the cooling groove 3, so that most of the heat on the multiple groups of array permanent magnets 9 will be taken away by the cooling water flowing in the inner barrel 1; the outer barrel 2 is used to protect the sensor and provide electromagnetic shielding; during detection, when the runway-shaped coil 8 contacts the high-temperature pipe 11 through the fireproof cloth base 4, the temperature of the runway-shaped coil 8 rises, but due to the presence of the elastic bottom insulation layer 10, it prolongs the heat transfer time, avoids demagnetization of the magnetic block, and thus prolongs the detection time. The detection target of detection at high temperature is finally completed, thereby realizing the detection of defects in the high-temperature pipeline 11; since the fireproof cloth substrate 4 has a certain ductility, when the sensor is adsorbed on the surface of the high-temperature pipeline 11, the bottom of the multiple array element sensors can adapt well to the curvature of the surface of the high-temperature pipeline 11, and the contact area with the surface of the high-temperature pipeline 11 is large, the energy conversion efficiency is higher, and the detection efficiency of the sensor is improved, so that the amplitude of the excited signal is increased by two to three times compared with the traditional sensor with a ceramic plate as the substrate, and the signal energy is large. Even when detecting difficult-to-detect defects after crossing the support, an effective echo signal can be obtained.

In specific implementation, there are two or three array element sensors. When the diameter of the high-temperature pipeline 11 is large, three array element sensors are suitable, and the detection effect is obvious. This part of the content is published in CN117266263A, and the patent name is a patent application for a narrow beam electromagnetic ultrasonic sensor and device for axial detection of pipeline defects; when the diameter of the high-temperature pipeline 11 is not large, two array element sensors are suitable, and relatively effective detection can be achieved while ensuring a reasonable size structure.

In specific implementation, multiple racetrack-shaped coils 8 are fixed to the bottom surface of the elastic bottom insulation layer 10 by high-temperature glue to prevent the racetrack-shaped coils 8 from melting and short-circuiting when the temperature of the high-temperature pipeline 11 is too high, thereby further improving the effectiveness of defect detection of the high-temperature pipeline 11.

In specific implementation, as shown in Figure 10, the insulation cavity 5 is filled with an intermediate insulation layer 12. During detection, the bottom of the outer barrel body 2 is in contact with the high temperature, so the temperature of the outer barrel body 2 rises, and then the heat is radiated to the inner barrel body 1, thereby affecting the cooling effect. However, due to the presence of the intermediate insulation layer 12, most of the heat on the outer barrel body 2 is prevented from being transferred to the inner barrel body 1 to a certain extent, thereby improving the cooling effect of the inner barrel body 1.

In specific implementation, the insulation cavity 5 and the top of the inner barrel body 1 are sealed by a cover plate 13, and a handle is fixed on the cover plate 13, which is convenient for placing the sensor on the high-temperature pipe 11 during detection and for lifting the sensor after the detection is completed.

During specific implementation, the handle is located on the portion of the cover plate 13 corresponding to the middle thermal insulation layer 12. The handle is a hollow handle 14. The ports after the plurality of track-shaped coils 8 are interconnected are provided with BNC connectors. The BNC connectors pass through the middle thermal insulation layer 12 and then come out from the hollow handle 14, which is convenient for connection with an electromagnetic detector. At the same time, the middle thermal insulation layer 12 is used to provide high-temperature protection for the BNC connector to prevent short circuits caused by high-temperature melting and deformation.

In specific implementation, as shown in Figures 3, 4 and 9, the cooling structure also includes two groups of spring compression and stretching mechanisms both arranged in the middle insulation layer 12, and the two groups of spring compression and stretching mechanisms are symmetrically arranged on both sides of the transverse direction or longitudinal direction of the multiple runway-shaped coils 8 (when performing axial defect detection on the high-temperature pipeline 11, the longitudinal direction of the multiple runway-shaped coils 8 is consistent with the axial direction of the high-temperature pipeline 11. At this time, the two groups of spring compression and stretching mechanisms are symmetrically arranged on both sides of the transverse direction of the multiple runway-shaped coils 8. When performing circumferential defect detection, the longitudinal direction of the multiple runway-shaped coils 8 is consistent with the circumferential direction of the high-temperature pipeline 11. At this time, the two groups of spring compression and stretching mechanisms are symmetrically arranged on both sides of the longitudinal direction of the multiple runway-shaped coils 8). Each group of spring compression and stretching mechanisms includes at least one spring stretching member 15, and each spring stretching member 15 includes a connector 151, a screw 152, a vertical column 153, a top plate 154, a spring cavity 157, a magnet 156, and a spring 155. The connector 151 is vertically fixed to the corresponding position of the cover plate 13, and the top end of the connector 151 is located above the cover plate 13, and the bottom end of the connector 151 is located below the cover plate 13. The connector 151 is provided with an internal threaded hole adapted to the screw 152, and the screw 152 is threadedly connected to the internal threaded hole on the connector 151. The top sleeve of the spring chamber 157 is fixed to the bottom end of the connector 151, and the top plate 154 is vertically fixed to the top of the vertical column 153. The vertical column 153 and the top plate 154 are all placed in the spring cavity tube 157, the top plate 154 is located below the connecting head 151, the bottom end of the vertical column 153 is exposed at the bottom of the spring cavity tube 157, and a limiting ring 158 is coaxially fixed on the inner wall of the bottom end of the spring cavity tube 157. The spring 155 slides up and down on the vertical column 153 and is located between the upper surface of the limiting ring 158 and the top plate 154. The bottom end of the vertical column 153 is hinged with a magnet 156 and the axial direction of the hinge shaft is parallel to the axial direction of the high-temperature pipeline 11. When in use, screw 152 is screwed, and screw 152 moves downward to push top plate 154, vertical column 153 and magnet 156 downward. At this time, spring 155 is compressed, and when magnet 156 moves down to close to the outer wall of high-temperature pipe 11, due to the suction force of magnet 156, magnet 156 is adsorbed to the outer wall of high-temperature pipe 11 through fireproof cloth base 4, thereby stretching fireproof cloth base 4, so that fireproof cloth base 4 is more closely fitted to the outer wall of high-temperature pipe 11, thereby making the curvature adaptability of the sensor to the high-temperature pipe 11 higher, and improving its detection accuracy. When the detection is completed, the sensor is separated from the pipe, and screw 152 is screwed in the opposite direction, screw 152 moves upward, and spring 155 recovers upward and pushes top plate 154 upward. The upward movement of top plate 154 drives vertical column 153 upward, so that the fireproof cloth base 4 is restored to its original state for the next use.

During specific implementation, the bottom surface of the magnet 156 is an inclined surface adapted to the circumference of the high-temperature pipe 11 , so as to further improve the curvature adaptability between the sensor and the high-temperature pipe 11 .

In this specific embodiment, each group of spring compression and stretching mechanisms includes two spring stretching members 15 evenly distributed along the axial direction of the high-temperature pipe 11, and the structure is standardized and rationalized, which improves the stability of the detection. The elastic bottom insulation layer 10 is aluminum silicate ceramic fiber paper. The middle insulation layer 12 is silica aerogel felt. The bottom end of the connector 151 is provided with an external thread, and the top end of the spring cavity 157 is provided with an internal thread, which facilitates the connection between the spring cavity 157 and the connector 151, and is easy to install and disassemble. The magnet 156 is a high-temperature resistant samarium cobalt material. The residual magnetic flux density of the magnet 156 is 1.1T, and the length × width × height of the magnet 156 is 10mm × 2.5mm × 10mm. The runway-type coil 8 is a double-layer PCB coil and its inner diameter and outer diameter are 2mm and 17mm respectively, and the number of turns of the runway-type coil 8 is 30 turns.

According to the analysis of different insulation substrates, the electromagnetic ultrasonic guided wave sensor with a ceramic plate substrate as the insulation substrate cannot adapt to the curvature of the surface of the high-temperature pipe 11, the bottom of the ceramic plate substrate does not completely contact the surface of the high-temperature pipe 11, the contact area with the surface of the high-temperature pipe 11 is small, and the distance between the two sides of the bottom of the ceramic plate substrate and the surface of the high-temperature pipe 11 is too large, and the energy conversion efficiency is very low; while the electromagnetic ultrasonic guided wave sensor with a fireproof cloth substrate 4 as the insulation substrate has elasticity, so it can adapt well to the curvature of the surface of the high-temperature pipe 11, has a large contact area with the surface of the high-temperature pipe 11, and has high energy conversion efficiency.

In order to verify the superiority of the electromagnetic ultrasonic guided wave sensor with the fireproof cloth substrate 4 as the heat insulation substrate in the present invention compared with the electromagnetic ultrasonic guided wave sensor with the ceramic plate substrate as the heat insulation substrate in detecting defects in the high-temperature pipeline 11, a verification experiment is performed as an example of the electromagnetic ultrasonic guided wave sensor shown in Figure 11 for circumferential defect detection of the high-temperature pipeline 11. The material of the high-temperature pipeline 11 is Q235, the length is 600mm, the outer diameter is 165mm, and the wall thickness is 3mm. The experimental results are shown in Figures 12 and 13. In Figure 12, the amplitude of the direct wave 161 and the primary echo 163 of the electromagnetic ultrasonic guided wave sensor with the ceramic plate substrate as the heat insulation substrate is very small, the signal-to-noise ratio is low, and the defect echo 162 is submerged in the noise, and it is not easy to determine the defect position; while in Figure 13, the electromagnetic ultrasonic guided wave sensor with the fireproof cloth substrate 4 as the heat insulation substrate has a large amplitude of the direct wave 161 and the primary echo 163, a high signal-to-noise ratio, and a clearly visible defect echo 162, which can accurately determine the circumferential defect position of the high-temperature pipeline 11.

In addition, in order to verify the performance of the electromagnetic ultrasonic guided wave sensor of the present invention in continuous detection at high temperature, a high temperature verification experiment is carried out using the electromagnetic ultrasonic guided wave sensor shown in FIG. 11 to detect defects in the circumferential cross-support of a 630°C high-temperature pipeline 11. During the experiment, the high-temperature pipeline 11 is heated to 630°C and insulated with thermal insulation materials. The electromagnetic ultrasonic guided wave sensor is located on the surface of the 630°C high-temperature pipeline 11 and continuously detects pipeline defects. The detection results at the 10th minute are shown in FIG. 14. FIG. 14 shows that when the electromagnetic ultrasonic guided wave sensor of the present invention is tested on a 630°C high-temperature pipeline for 10 minutes, the direct wave 161, the primary echo 163, and the defect echo 162 are clearly visible, with a high signal-to-noise ratio, and the circumferential defect position of the high-temperature pipeline 11 can be accurately determined.

Therefore, the electromagnetic ultrasonic guided wave sensor of the present invention, that is, the electromagnetic ultrasonic guided wave sensor for high-temperature pipeline 11 defect detection with the fireproof cloth base 4 as the thermal insulation base, has a high energy conversion efficiency, which also means that the sensor has a large signal amplitude when performing high-temperature pipeline 11 defect detection, high resolution of defect detection, and obvious detection effect. At the same time, the performance is still good at high temperature, and the surface of the 630°C high-temperature pipeline 11 can be detected for up to 10 minutes, and the detection signal signal-to-noise ratio is high.

The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims (10)

1. An electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection, characterized in that it includes a cooling structure and an electromagnetic ultrasonic guided wave sensor body; The cooling structure comprises a double-layer cooling shell, a water inlet pipe (6), and a water outlet pipe (7). The double-layer cooling shell comprises an inner barrel (1) and an outer barrel (2). The middle part of the barrel bottom of the inner barrel (1) protrudes toward the inner barrel cavity so that a cooling groove (3) is formed in the middle part of the barrel bottom. The barrel bottom of the outer barrel (2) is a fireproof cloth base (4). An insulating cavity (5) is provided between the inner barrel (1) and the outer barrel (2). The top of the insulating cavity (5) is sealed. The top of the inner barrel (1) is also sealed. One end of the water inlet pipe (6) is connected to the inner barrel (1), and the other end of the water inlet pipe (6) is exposed to the double-layer cooling shell. One end of the water outlet pipe (7) is connected to the inner barrel (1), and the other end of the water outlet pipe (7) is exposed to the double-layer cooling shell. The electromagnetic ultrasonic guided wave sensor body comprises a plurality of array element sensors, each array element sensor comprises a runway-shaped coil (8) and two groups of array permanent magnets (9) pressed on the upper part of the runway-shaped coil (8) and matched with the runway-shaped coil (8), each two groups of array permanent magnets (9) are arranged side by side along the transverse direction of the runway-shaped coil (8), each group of array permanent magnets (9) comprises a plurality of magnetic blocks arranged side by side along the longitudinal direction of the runway-shaped coil (8), the plurality of runway-shaped coils (8) are arranged side by side in a straight line along the transverse direction of the runway-shaped coil (8) and are interconnected to form a T-mode transmitting coil or an SH wave transmitting coil, and the plurality of groups of array permanent magnets (9) The plurality of array permanent magnets (9) are all located in the cooling groove (3) of the inner barrel (1), and the top surfaces and four side surfaces of the plurality of array permanent magnets (9) are respectively in contact with the four groove walls and groove bottom of the cooling groove (3); an elastic bottom heat insulation layer (10) is provided between the plurality of array permanent magnets (9) and the plurality of runway-shaped coils (8), and the elastic bottom heat insulation layer (10) is fixed outside the cooling groove (3); the upper surfaces of the plurality of runway-shaped coils (8) are fixed to the bottom surface of the elastic bottom heat insulation layer (10); the ports of the plurality of runway-shaped coils (8) after being interconnected pass through the heat insulation cavity (5) and are exposed to the double-layer cooling shell; and the lower surfaces of the plurality of runway-shaped coils (8) are in contact with the middle of the fireproof cloth base (4). 2. The electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection according to claim 1 is characterized in that the number of array element sensors is two or three. 3. The electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection according to claim 2 is characterized in that a plurality of racetrack-shaped coils (8) are fixed to the bottom surface of the elastic bottom insulation layer (10) by high-temperature glue. 4. The electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection according to claim 3, characterized in that the thermal insulation cavity (5) is filled with an intermediate thermal insulation layer (12). 5. The electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection according to claim 4 is characterized in that the insulation cavity (5) and the top of the inner barrel (1) are sealed by a cover plate (13), and a handle is fixed on the cover plate (13). 6. The electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection according to claim 5 is characterized in that the handle is located on the portion of the cover plate (13) corresponding to the middle thermal insulation layer (12), the handle is a hollow handle (14), and the ports after the plurality of track-shaped coils (8) are interconnected are provided with a BNC connector, and the BNC connector passes through the middle thermal insulation layer (12) and then passes out from the hollow handle (14). 7. The electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection according to claim 6 is characterized in that the cooling structure also includes two groups of spring compression and stretching mechanisms both arranged in the middle insulation layer (12), the two groups of spring compression and stretching mechanisms are symmetrically arranged on both sides of the plurality of runway-shaped coils (8) in the transverse direction or the longitudinal direction, each group of spring compression and stretching mechanisms includes at least one spring stretching member (15), each spring stretching member (15) includes a connector (151), a screw (152), a vertical column (153), a top plate (154), a spring cavity (157), a magnet (156), and a spring (155), the connector (151) is vertically fixed to a corresponding position of the cover plate (13), the top end of the connector (151) is located above the cover plate (13), and the bottom end of the connector (151) is located below the cover plate (13), and the connector (151) is provided with a spring having a spring portion and a spring portion. The screw (152) is threadedly connected to the internal threaded hole on the connector (151). The top outer sleeve of the spring chamber (157) is fixed to the bottom end of the connector (151). The top plate (154) is vertically fixed to the top of the vertical column (153). The vertical column (153) and the top plate (154) are both placed in the spring chamber (157). The top plate (154) is located below the connector (151). The bottom end of the column (153) is exposed at the bottom of the spring cavity (157); a limiting ring (158) is coaxially fixed on the inner wall of the bottom end of the spring cavity (157); the spring (155) is slidably sleeved on the vertical column (153) and is located between the upper surface of the limiting ring (158) and the top plate (154); the bottom end of the vertical column (153) is hinged with a magnet (156) and the axial direction of the hinge shaft is parallel to the axial direction of the high-temperature pipe (11). 8. The electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection according to claim 7, characterized in that the bottom surface of the magnet (156) is an inclined surface adapted to the circumference of the high-temperature pipeline (11). 9. The electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection according to claim 8, characterized in that each set of spring compression and tensioning mechanisms comprises two spring tensioning members (15) uniformly distributed along the axial direction of the high-temperature pipeline (11). 10. The electromagnetic ultrasonic guided wave sensor for high-temperature pipeline defect detection according to claim 9, characterized in that the bottom end of the connector (151) is provided with an external thread, and the top end of the spring cavity (157) is provided with an internal thread.