CN-122017023-A - Ultrasonic guided wave on-line monitoring device and method suitable for high-temperature pipeline

CN122017023ACN 122017023 ACN122017023 ACN 122017023ACN-122017023-A

Abstract

The invention relates to the technical field of nondestructive testing of high-temperature pipelines, and particularly discloses an ultrasonic guided wave on-line monitoring device suitable for the high-temperature pipelines, which comprises a laser annular array, a laser guided wave excitation module, a fiber bragg grating sensor network, an optical fiber sensing receiving module and a central controller, wherein the laser guided wave excitation module and the optical fiber sensing receiving module are controlled by the central controller; the laser guided wave excitation module is connected with the laser annular array, the optical fiber sensing receiving module is connected with the optical fiber grating sensor network, the optical fiber grating sensor network is arranged on the outer wall of the pipeline, each optical fiber grating sensor in the optical fiber grating sensor network comprises a plurality of measuring points, and the central controller is electrically connected with the optical fiber sensing receiving module and the laser guided wave excitation module. According to the invention, the manual intervention degree in a high-temperature environment is reduced, the operation and maintenance cost and the safety risk are reduced, the monitoring automation level is improved, and the distributed real-time online monitoring of the structural health of the high-temperature pipeline is realized.

Inventors

QING XINLIN
WANG SHUO
HE QIHAN
LIN ZHIRONG
ZHAO JING
LU YE

Assignees

厦门大学

Dates

Publication Date: 20260512
Application Date: 20260224

Claims (10)

1. The ultrasonic guided wave on-line monitoring device suitable for the high-temperature pipeline is characterized by comprising a laser annular array, a laser guided wave excitation module, a fiber bragg grating sensor network, a fiber optic sensing receiving module and a central controller, wherein the laser guided wave excitation module and the fiber optic sensing receiving module are controlled by the central controller, the laser guided wave excitation module is connected with the laser annular array, the fiber optic sensing receiving module is connected with the fiber bragg grating sensor network, the fiber bragg grating sensor network is arranged on the outer wall of the pipeline, each fiber bragg grating sensor in the fiber bragg grating sensor network comprises a plurality of measuring points, and the central controller is electrically connected with the fiber optic sensing receiving module and the laser guided wave excitation module.
2. The ultrasonic guided wave on-line monitoring device for high temperature pipelines of claim 1, wherein the laser annular array comprises a base, a bracket, a fixed slide block, a laser emission probe, a positioning bolt and a jackscrew.
3. The ultrasonic guided wave on-line monitoring device for the high-temperature pipeline according to claim 2, wherein the laser emission probe is connected with the bracket through a fixed sliding block, the relative height between the probe and the pipeline is adjusted through a positioning bolt, and the incidence angle and the relative distance between the probe and the bracket are adjusted through a jackscrew.
4. The ultrasonic guided wave on-line monitoring device for the high-temperature pipeline according to claim 1, wherein the fiber bragg grating sensor is a high-temperature-resistant fiber bragg grating sensor, and the highest temperature tolerance is 500-800 ℃.
5. The ultrasonic guided wave on-line monitoring device for the high-temperature pipeline according to claim 1, wherein the fiber bragg grating sensor networks are arranged in parallel along the axial direction of the pipeline, each fiber bragg grating sensor in the fiber bragg grating sensor networks is uniformly distributed at intervals of 30-60 degrees along the circumferential direction of the pipeline, and each fiber bragg grating sensor is arranged at intervals of 10-30 cm along the axial direction of the pipeline.
6. The ultrasonic guided wave on-line monitoring device for the high-temperature pipeline according to claim 1, wherein the optical fiber sensing receiving module is synchronously connected with a plurality of optical fiber grating sensors in the optical fiber grating sensor network.
7. The ultrasonic guided wave on-line monitoring device for the high-temperature pipeline according to claim 1, wherein the central controller comprises a user control interface, a signal processing module and an image display module, the signal processing module is used for sequentially carrying out low-pass filtering, effective time domain segment interception and signal interception on an original signal from the optical fiber sensing receiving module and extracting time domain features, the signal processing module is also used for comparing a currently acquired damage signal with a pre-stored nondestructive baseline signal and calculating a damage index of each measuring point, the damage index is a time domain feature difference quantification value of the damage signal and the baseline signal, the image display module is used for displaying a damage index distribution map, an ultrasonic guided wave propagation image and a pipeline health state evaluation result in real time, the central controller is used for presetting a damage index threshold value, and the central controller is also used for controlling excitation parameters of the laser excitation module.
8. The ultrasonic guided wave on-line monitoring device for the high-temperature pipeline according to claim 1, wherein the laser annular array, the laser guided wave excitation module, the fiber bragg grating sensor network, the fiber optic sensing receiving module and the central controller form a closed loop monitoring system on the space layout, and the laser excitation points and the fiber optic sensing points are distributed in a non-overlapping mode in the circumferential direction of the pipeline.
9. Use of an ultrasonic guided wave on-line monitoring device for high temperature pipelines according to any of claims 1-8.
10. A monitoring method based on the ultrasonic guided wave on-line monitoring device for high temperature pipelines according to any one of claims 1-8, characterized by comprising the following steps: (1) The method comprises the steps of collecting a baseline signal, namely controlling a laser guided wave excitation module to emit a five-period sine modulation excitation signal through a central controller under the nondestructive state of a high-temperature pipeline, irradiating the surface of the pipeline by a laser beam through an annular array structure at a set angle to excite Lamb waves to propagate along the pipe wall, synchronously sensing ultrasonic guided wave response signals through all measuring points of a fiber bragg grating sensor network, collecting the ultrasonic guided wave response signals through an optical fiber sensing receiving module, and transmitting and storing the ultrasonic guided wave response signals in the central controller as a baseline signal set; (2) The signal to be measured is collected, wherein the operation of the step (1) is repeated in the running process of the high-temperature pipeline, and the ultrasonic guided wave response signal in the current state is collected and used as a signal set to be measured; (3) Preprocessing an original signal, namely respectively carrying out low-pass filtering on the baseline signal set obtained in the step (1) and the signal set to be detected obtained in the step (2) by adopting the following filtering formula: Wherein a k 、b k is a filter coefficient, x (n) is an input signal, and y (n) is a filtered signal; (4) And (3) performing equal time truncation on the filtered signals, namely performing equal time length truncation on all the signals obtained in the step (3), wherein the truncation formula is as follows: Wherein x cut (t) is a truncated signal, t is continuous time, the starting time t s is based on the arrival time of the first arrival of the signal, and the ending time t e is based on the shortest signal duration of all the measuring points; (5) Injury index calculation injury index (Damage Index, DI) was calculated for each measurement point: Wherein DI is the damage index of the ith measuring point, the relative energy change of the signal at the measuring point relative to the baseline is represented, u (i) is the current measuring point damage signal, and u (i) is the corresponding baseline signal; (6) Setting a damage index threshold value as 3 sigma, wherein sigma is the standard deviation of DI of all measuring points in a baseline signal set, and judging that the region where any measuring point is located is damaged if DI of any measuring point is more than 3 sigma; (7) And outputting the result, namely outputting a damage index distribution diagram, the position of the superscalar point and a damage evaluation result through a central controller.

Description

Ultrasonic guided wave on-line monitoring device and method suitable for high-temperature pipeline Technical Field The invention belongs to the technical field of nondestructive testing of high-temperature pipelines, and particularly relates to an ultrasonic guided wave on-line monitoring device and method suitable for the high-temperature pipelines. Background In the high-end industrial fields of aerospace, supercritical thermal power, nuclear power, metallurgy and the like, core equipment such as a high-temperature pipeline, a combustion chamber, a reaction kettle and the like is used for a long time under the high-temperature working condition of 200-500 ℃, and is subjected to complex environments such as high pressure, strong corrosion, strong electromagnetic interference and the like, and the inner wall of the equipment is extremely easy to be damaged in various forms such as oxidation corrosion, fatigue crack expansion, wall thickness reduction and the like. If monitoring and early warning cannot be realized in time, important safety accidents such as medium leakage and explosion are extremely easy to occur, so that the research and development of a non-contact type high-temperature pipeline monitoring technology is important. Ultrasonic guided wave technology has been widely used in the field of nondestructive testing and health monitoring of tubular structures by virtue of the unique advantages of long propagation distance, small attenuation, sensitivity to cross section changes, and the like. The ultrasonic guided wave is generated by the excitation of the mechanical vibration of the excitation source, and when the vibration propagates in the waveguide, reflection, transmission and modal conversion can possibly occur at the interface of the elastic medium, so that the ultrasonic waves generated by the same sound source can form waves in different forms through waveform conversion, and the application range of the ultrasonic waves is enlarged. The guided wave carries characteristic information of an excitation source and a material, and can accurately infer physical parameters such as the size, the position and the like of internal defects of a pipeline structure by combining with the change rule of sound wave intensity, so that an ultrasonic guided wave technology is often used for high-temperature pipeline corrosion monitoring work. At present, the existing ultrasonic guided wave monitoring technology still has obvious limitations that the working temperature of an electromagnetic ultrasonic transducer is limited by the Curie temperature of a permanent magnet, the problems of coil impedance change, thermal noise aggravation and the like can occur under a high-temperature environment, so that the signal intensity and the signal-to-noise ratio are obviously reduced, the piezoelectric material and the couplant performance of the conventional piezoelectric ultrasonic transducer can be attenuated sharply and even completely fail, and the conventional piezoelectric ultrasonic transducer can work transiently under a higher-temperature environment (such as 500 ℃) through a heat insulation design, but the unreliability and the variability of a coupling state can seriously influence the signal consistency and the measurement precision, and the practical requirement of long-term online monitoring is difficult to meet. Therefore, the existing monitoring technology based on the contact ultrasonic guided wave transducer is limited by the temperature resistance, signal stability and coupling reliability of the transducer, and off-line detection can be generally only carried out after equipment is stopped and cooled, so that the core requirements of long-term, real-time and on-line monitoring of a high-temperature pipeline can not be met, the operation and maintenance cost and the safety risk of the equipment are greatly increased, and the dynamic development process of damage can not be captured in real time. In summary, a novel ultrasonic guided wave on-line monitoring device and method are developed, the problems of direct damage and unstable coupling of high temperature to a transducer are fundamentally avoided, further high-precision, high-reliability and real-time on-line monitoring of high-temperature pipeline damage is realized, and the device and method have important theoretical significance and engineering application value in the field of pipeline defect detection. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides an ultrasonic guided wave on-line monitoring device and method suitable for a high-temperature pipeline, which realize non-contact detection in a high-temperature environment through laser excitation without a coupling agent, and avoid electromagnetic interference through optical fiber sensing, so that ultrasonic guided wave signals of the high-temperature pipeline and signal changes caused by pipeline cracks or corrosion can be acquired, and t