Movable ultrasonic reflection clamping member for pipe and ultrasonic guided wave testing calibration method

Abstract

A movable ultrasonic reflection clamping member for a pipe and an ultrasonic guided wave testing calibration method. The movable ultrasonic reflection clamping member (5) is openable and closable, can be mounted on the outer wall of a pipe and is used for reflecting ultrasonic guided waves. A main body of the movable ultrasonic reflection clamping member (5) consists of two semicircular components (1) of which inner walls are covered with ultrasonic coupling agent coatings (2), a constraint connecting member (3) and an opening and closing connecting member (4). The ultrasonic guided wave testing calibration method comprises: performing guided wave testing on a calibration pipe (6) provided with a movable ultrasonic reflection clamping member (5), so as to acquire a set of data comprising the echo amplitude and the mounting point (7) position of the reflection clamping member, and finally calculating data, such as a DAC, which represents the ultrasonic guided wave echo attenuation of the pipe.

Description

A movable ultrasonic reflection fixture for pipelines and ultrasonic guided wave detection calibration method Technical Field

[0001] The present invention is applied to the technical field of ultrasonic guided wave nondestructive testing, and particularly relates to a pipeline movable ultrasonic reflection clamp and an ultrasonic guided wave detection calibration method. Background Art

[0002] Pipe structures with complex geometric morphology have been widely used in various important industrial fields such as traditional thermal power generation, nuclear power, and petrochemicals. During the long-term operation of facilities, pipelines used for fluid transportation, heat exchange and other functions are subject to factors such as fluid erosion, high temperature and high pressure, and their pipe walls are prone to defects such as large-scale and pitting corrosion, fatigue cracks and welding cracks. In order to ensure the safe, stable and efficient operation of equipment and facilities, it is necessary to conduct effective non-destructive testing on pipelines on a regular basis to detect defects in a timely manner. Ultrasonic guided wave non-destructive testing technology is based on the characteristics of guided waves propagating along the full thickness of the pipeline wall and being able to pass through bends. Through single-point positioning detection of the probe, long-distance and efficient non-destructive testing of defects in geometrically complex pipelines can be achieved. It has been widely used for defect detection in large pipelines, and is gradually showing its application prospects in the detection of small-diameter pipelines such as heat exchange tubes.

[0003] Due to acoustic attenuation and beam diffusion during ultrasonic propagation in a medium, the echo amplitude of a defect of the same size reflected at a longer acoustic path is smaller. Therefore, quantitative defect assessment based on echo amplitude requires compensation for the attenuation of echo amplitude with acoustic path. In ultrasonic testing, distance-amplitude curves (DACs) and depth-compensation curves (TCGs) are used to characterize and compensate for the echo attenuation with acoustic path for specific structures. Conventional methods for calibrating DAC and TCG curves typically involve preparing several calibration specimens of consistent material and shape. Artificial defects of the same size are machined at different depths on each specimen. The echo depth and amplitude are then ultrasonically measured, and a depth-echo amplitude curve is fitted to determine the DAC. However, for long-distance pipelines with complex geometries, numerous bends can affect the attenuation characteristics of ultrasonic guided waves. Conventional methods for machining defects at different locations on multiple pipes are extremely costly and require a large number of long-distance sample pipes. Furthermore, the DAC varies between pipes with different curvatures, necessitating the machining of a series of long-distance sample pipes for each curved pipe. Therefore, the ultrasonic guided wave detection calibration of such pipelines requires a calibration method with a small number of sample pipes and a certain degree of versatility for pipelines of different specifications to avoid excessively high calibration operation costs.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to provide a movable ultrasonic reflection fixture for pipelines and an ultrasonic guided wave detection calibration method, which has a small demand for sample pipes, low operating costs, and is suitable for ultrasonic guided wave calibration of long-distance complex pipelines, and realizes the calibration of characterizing echo attenuation curve data for ultrasonic guided wave detection of complex curved pipes.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A movable ultrasonic reflection clip for pipelines has an open-and-close structure. The main body consists of two semi-cylindrical components. The inner walls of the two semi-cylindrical components are cylindrical surfaces, and the inner wall surfaces are covered with an ultrasonic coupling agent coating. One end of the two semi-cylindrical components is movably connected together by a constraint connector to constrain the relative displacement of the two semi-cylindrical components; the other ends of the two semi-cylindrical components are detachably connected together by an open-and-close connector to constrain or release the relative rotation of the two semi-cylindrical components.

[0008] A further improvement of the present invention is that its installation method is as follows: the movable ultrasonic reflection card is installed on the outer wall of the pipeline, and the cylindrical inner wall covered with the ultrasonic coupling agent coating is adhered to the outer wall of the pipeline, so that the ultrasonic coupling agent coating is in full contact with the outer wall of the pipeline; then the opening and closing connecting piece is operated to constrain the relative rotation of the two semi-cylindrical components, so that the movable ultrasonic reflection card is fixed on the pipeline.

[0009] A further improvement of the present invention is that one or more movable ultrasonic reflection clips are installed on the outer wall of the pipeline.

[0010] A further improvement of the present invention is that the semi-cylindrical component is made of aluminum alloy.

[0011] A further improvement of the present invention is that the inner diameter of the semi-cylindrical component is larger than the diameter of the outer wall of the pipe.

[0012] A further improvement of the present invention is that the ultrasonic coupling agent coating layer adopts a pressure-sensitive adhesive layer.

[0013] A further improvement of the present invention is that the restraining connecting member adopts a metal hinge.

[0014] A pipeline ultrasonic guided wave detection calibration method, based on the aforementioned movable pipeline ultrasonic reflection card, is used to calibrate and characterize pipeline ultrasonic guided wave echo attenuation data, comprising the following steps:

[0015] S1. Mark several mounting points for the movable ultrasonic reflector on the straight section of the calibration sample tube, ensuring that the distances between the mounting points can be accurately measured. Then, install the movable ultrasonic reflector at the first mounting point.

[0016] S2. Record the axial coordinate x of the installation point on the pipei , i is the installation point number, i = 1, 2, 3..., the ultrasonic guided wave detection technology is used to measure the ultrasonic guided wave reflection echo signal at the movable ultrasonic reflection card, and the card echo amplitude in the recorded signal is A i , then remove the movable ultrasonic reflection card, clean the ultrasonic coupling agent remaining on the pipe surface, and install the movable ultrasonic reflection card at the next marking point;

[0017] S3. Repeat the process shown in step S2 until the axial coordinates x of all mounting points are measured. i And the waveguide reflection echo amplitude data A i ;

[0018] S4. Axial coordinate x of each mounting point i and echo amplitude data A i , the echo attenuation data characterizing the pipeline ultrasonic guided wave is obtained through data fitting calculation.

[0019] A further improvement of the present invention is that the data characterizing the attenuation of the pipeline ultrasonic guided wave echo includes a distance-amplitude curve DAC.

[0020] Compared with the conventional ultrasonic attenuation curve and compensation curve calibration method, the present invention has at least the following beneficial technical effects:

[0021] (1) The present invention provides a movable ultrasonic reflector fixture for pipelines, which can replace the artificial defects in conventional methods and be used to trigger ultrasonic guided wave echoes. The movable fixture design not only avoids the defect processing process, but is also reusable and can be installed at different locations on the pipeline to simulate defects in different locations. Calibration of a sample pipe can achieve the measurement of attenuation and compensation curves, significantly reducing the cost of pipeline calibration;

[0022] (2) The present invention provides a pipeline ultrasonic guided wave detection calibration method that can achieve non-destructive calibration for pipelines with various complex bending geometries. Users can freely select the location of the ultrasonic reflection point required for calibration based on the sample pipe morphology, so it is versatile for calibrating pipelines with different bending trends. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic diagram of a movable ultrasonic reflective card according to the present invention and its installation on a pipeline.

[0024] FIG2 is a flowchart showing specific implementation steps of the pipeline ultrasonic guided wave detection calibration method according to the present invention.

[0025] FIG3 is a diagram of ultrasonic guided wave detection signals according to the present invention.

[0026] FIG4 is a DAC curve fitting signal diagram according to the present invention.

[0027] Explanation of the reference numerals: 1-semi-cylindrical component, 2-ultrasonic coupling agent coating, 3-constraint connector, 4-opening and closing connector, 5-movable ultrasonic reflection card, 6-calibration sample tube, 7-installation point. DETAILED DESCRIPTION

[0028] The technical solutions of the present invention are further described and illustrated in detail below in conjunction with specific embodiments of the present invention and the corresponding drawings. The described embodiments are only some embodiments of the present invention and are not intended to be exhaustive. All other embodiments obtained by those skilled in the art without creative effort are intended to fall within the scope of protection of the present invention.

[0029] As shown in Figure 1, the present invention provides a movable ultrasonic reflection card for pipelines. The overall structure of the movable ultrasonic reflection card 5 is an open-closing type. The main body is composed of two semi-cylindrical components 1. The inner walls of the two semi-cylindrical components 1 are cylindrical surfaces, and the inner wall surfaces are covered with an ultrasonic coupling agent coating 2. One end of the two semi-cylindrical components 1 is movably connected together by a constraint connector 3, which is used to constrain the relative displacement of the two semi-cylindrical components 1; the other ends of the two semi-cylindrical components 1 are detachably connected together by an open-closing connector 4, so as to realize the constraint or release of the relative rotation of the two semi-cylindrical components 1.

[0030] The installation method is as follows: the movable ultrasonic reflection card 5 is installed on the outer wall of the pipeline, and the cylindrical inner wall covered with the ultrasonic coupling agent coating 2 is attached to the outer wall of the pipeline, so that the ultrasonic coupling agent coating 2 is in full contact with the outer wall of the pipeline; then the opening and closing connector 4 is operated to constrain the relative rotation of the two semi-cylindrical components 1, so that the movable ultrasonic reflection card 5 is fixed on the pipeline.

[0031] The present invention provides a pipeline ultrasonic guided wave detection calibration method for calibrating pipeline ultrasonic guided wave echo attenuation data, comprising the following steps:

[0032] S1. Mark several movable ultrasonic reflective card mounting points 7 on the straight section of the calibration sample tube 6. The spacing between mounting points 7 and 7 is required to be accurately measured; then install the movable ultrasonic reflective card 5 at the first mounting point;

[0033] S2. Record the axial coordinate x of the installation point on the pipe i , i is the installation point number, i = 1, 2, 3..., the ultrasonic guided wave detection technology is used to measure the ultrasonic guided wave reflection echo signal at the movable ultrasonic reflection card 5, and the card echo amplitude in the recorded signal is A i , then remove the movable ultrasonic reflection card 5, clean the ultrasonic coupling agent remaining on the pipe surface, and install the movable ultrasonic reflection card 5 at the next marking point;

[0034] S3. Repeat the process shown in step S2 until the axial coordinates x of all mounting points 7 are measured. i And the waveguide reflection echo amplitude data A i ;

[0035] S4. Axial coordinate x through each mounting point 7 i and echo amplitude data A i , the echo attenuation data characterizing the pipeline ultrasonic guided wave is obtained through data fitting calculation.

[0036] Example

[0037] The schematic diagram of the movable ultrasonic reflection clip for pipelines and its installation on the pipeline is shown in Figure 1. The overall structure of the movable ultrasonic reflection clip for pipelines is open and close type, and the main body is composed of two semi-cylindrical components 1, and the material in the embodiment is aluminum alloy. The inner walls of the two semi-cylindrical components 1 are cylindrical surfaces, and the cylindrical diameter is slightly larger than the outer diameter of the calibration sample tube. For the calibration sample tube with an outer diameter of 20.0 mm, the cylindrical surface diameter of the semi-cylindrical component 1 of the clip is designed to be 20.5 mm in the embodiment. The inner wall surface of the semi-cylindrical component 1 is covered with an ultrasonic coupling agent coating 2, and a pressure-sensitive adhesive layer is used in the embodiment with a thickness of 0.2 mm. One end of the two semi-cylindrical components 1 is a constraining connector 3, and a metal hinge is used in the embodiment. The other end adopts an open and close connector 4, and the embodiment adopts bolts and screw holes respectively placed on the two semi-cylindrical components 1 to achieve an open and close connection.

[0038] As shown in Figure 1, a movable ultrasonic reflective clip 5 is mounted on the outer wall of a pipe. The clip's cylindrical inner wall, covered with an ultrasonic couplant coating 2, adheres to the pipe's outer wall, ensuring full contact between the ultrasonic couplant coating 1 and the pipe's outer wall, preventing the clip from sliding axially along the pipe. In this embodiment, the bolt of the retractable connector 4 is rotated into the screw hole on the other side and further tightened with a torque wrench until the bolt preload reaches the set value, ensuring that the preload force remains the same when the clip is subsequently installed at different locations.

[0039] As shown in FIG1 and FIG2 , a pipeline ultrasonic guided wave detection calibration method is used to calibrate pipeline ultrasonic guided wave echo attenuation data, such as a distance-amplitude curve DAC. The embodiment includes the following steps:

[0040] S1. Mark several mounting points 7 of the movable ultrasonic reflector 5 on a calibration sample tube 6 of the same specification as the test pipe. The spacing between the points is uniform and can be accurately measured. In the embodiment, the spacing between the mounting points is approximately 2m. Then install the movable ultrasonic reflector 5 at the first mounting point.

[0041] S2. Record the axial coordinate x of the installation point on the pipe i, i is the mark point number, i = 1, 2, 3..., use ultrasonic guided wave detection technology to measure the ultrasonic guided wave reflection echo signal caused by the movable ultrasonic reflection card, and record the card echo amplitude as A i , then remove the movable ultrasonic reflection card 5, clean the ultrasonic coupling agent remaining on the pipe surface, and install the movable ultrasonic reflection card at the next marking point;

[0042] S3. Repeat the process shown in step S2 until the axial coordinates x of all mounting points 7 are measured. i and echo amplitude data A i The guided wave detection result at the fifth installation point in the embodiment is shown in FIG3 , which records the axial coordinate x5 of the echo reflected by the card and its echo amplitude A5.

[0043] S4. Axial coordinate x through each mounting point 7 i and echo amplitude data A i , fitting and calculating the distance-amplitude curve DAC or depth compensation curve TCG of ultrasonic guided wave. As shown in FIG4 , the axial coordinate x of the mounting point 7 measured in the embodiment is i and echo amplitude A i Mark them on the signal graph as points and use an exponential function to fit the DAC curve.

[0044] The above description is merely one embodiment of the present invention and is not intended to limit the present invention. Other embodiments may be obtained by modifying any parameters or data involved without creative effort by those skilled in the art. Any modifications, substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A pipeline movable ultrasonic reflection card, characterized in that: The movable ultrasonic reflection card (5) has an overall structure of an open-and-close type, and its main body is composed of two semi-cylindrical components (1). The inner walls of the two semi-cylindrical components (1) are cylindrical surfaces, and the inner wall surfaces are covered with an ultrasonic coupling agent coating (2). One end of the two semi-cylindrical components (1) is movably connected together through a constraint connector (3) to constrain the relative displacement of the two semi-cylindrical components (1); the other ends of the two semi-cylindrical components (1) are detachably connected together through an open-and-close connector (4) to realize the constraint or release of the relative rotation of the two semi-cylindrical components (1).

2. The pipeline movable ultrasonic reflection card according to claim 1, characterized in that: The installation method is as follows: a movable ultrasonic reflection card (5) is installed on the outer wall of a pipeline, and a cylindrical inner wall covered with an ultrasonic coupling agent coating (2) is attached to the outer wall of the pipeline, so that the ultrasonic coupling agent coating (2) is in full contact with the outer wall of the pipeline; then, an opening and closing connecting piece (4) is operated to constrain the relative rotation of the two semi-cylindrical components (1), so that the movable ultrasonic reflection card (5) is fixed on the pipeline.

3. The pipeline movable ultrasonic reflection card according to claim 2, characterized in that: One or more movable ultrasonic reflection cards (5) are installed on the outer wall of the pipeline.

4. The pipeline movable ultrasonic reflection card according to claim 2, characterized in that: The semi-cylindrical component (1) is made of aluminum alloy.

5. The pipeline movable ultrasonic reflection card according to claim 2, characterized in that: The inner diameter of the semi-cylindrical component (1) is greater than the diameter of the outer wall of the pipeline.

6. The movable ultrasonic reflection card for pipeline according to claim 2, characterized in that: The ultrasonic coupling agent coating (2) adopts a pressure-sensitive adhesive layer.

7. The pipeline movable ultrasonic reflection card according to claim 2, characterized in that: The restraining connecting piece (3) adopts a metal hinge.

8. A pipeline ultrasonic guided wave detection calibration method, characterized in that: The method is based on a pipeline movable ultrasonic reflection card according to any one of claims 1 to 7, and is used to calibrate and characterize pipeline ultrasonic guided wave echo attenuation data, comprising the following steps: S1. Mark several mounting points (7) of the movable ultrasonic reflective card (5) on the straight tube section of the calibration sample tube (6), requiring that the distance between the mounting points (7) and the mounting points (7) can be accurately measured; then install the movable ultrasonic reflective card (5) at the first mounting point; S2. Record the axial coordinate x of the installation point on the pipe i , i is the installation point number, i=1,2,3..., the ultrasonic guided wave reflection echo signal at the movable ultrasonic reflection card (5) is measured using ultrasonic guided wave detection technology, and the card echo amplitude in the recorded signal is A i , then remove the movable ultrasonic reflection card (5), clean the ultrasonic coupling agent remaining on the surface of the pipeline, and install the movable ultrasonic reflection card (5) at the next marking point; S3. Repeat the process shown in step S2 until the axial coordinates x of all mounting points (7) are measured. i And the waveguide reflection echo amplitude data A i ; S4. Axial coordinate x through each mounting point (7) i and echo amplitude data A i , the echo attenuation data characterizing the pipeline ultrasonic guided wave is obtained through data fitting calculation.

9. A pipeline ultrasonic guided wave detection calibration method according to claim 8, characterized in that: The data characterizing the echo attenuation of pipeline ultrasonic guided waves include the distance-amplitude curve DAC.

Images