CN-121994910-A - Hydrogen-doped pipeline detection method based on eddy current and magnetic leakage composite detection

CN121994910ACN 121994910 ACN121994910 ACN 121994910ACN-121994910-A

Abstract

The invention provides a hydrogen-doped pipeline detection method based on eddy current and magnetic leakage composite detection, which relates to the technical field of hydrogen-doped pipeline detection and comprises the steps of obtaining a reference magnetic field distribution vector and a reference electromagnetic induction response matrix of a hydrogen-doped pipeline, constructing a composite detection reference field model, executing magnetic leakage response collection and abnormal field reconstruction under defect disturbance of the hydrogen-doped pipeline, extracting an abnormal magnetic field gradient change set, generating a defect induction magnetic field disturbance distribution map, executing eddy current response disturbance recognition induced by micro cracks on the near surface of the hydrogen-doped pipeline, extracting a near surface current density abnormal change sequence, generating a crack disturbance response feature map, carrying out multi-source disturbance feature fusion discrimination on the abnormal magnetic field gradient change set and the near surface current density abnormal change sequence, and outputting a defect distribution result and a defect grade assessment result of the hydrogen-doped pipeline, so that full-scale defect recognition of the hydrogen-doped pipeline is realized through eddy current and magnetic leakage composite detection, working condition disturbance is effectively restrained, and defect detection accuracy and reliability are improved.

Inventors

DING CHUNXIONG
ZHENG KAI
ZHU QINGNAN
YU YANPING

Assignees

江苏省特种设备安全监督检验研究院

Dates

Publication Date: 20260508
Application Date: 20260409

Claims (10)

1. The method for detecting the hydrogen-doped pipeline based on the eddy current and magnetic leakage composite detection is characterized by comprising the following steps of: acquiring a reference magnetic field distribution vector and a reference electromagnetic induction response matrix of the hydrogen-doped pipeline in a complete state, and constructing a composite detection reference field model of the hydrogen-doped pipeline; based on a composite detection reference field model, carrying out leakage magnetic field response acquisition and abnormal field reconstruction under defect disturbance of the hydrogen-doped pipeline, extracting an abnormal magnetic field gradient change set, and generating a defect induction magnetic field disturbance distribution map; Based on the composite detection reference field model, executing eddy current response disturbance recognition induced by the near-surface microcracks of the hydrogen-doped pipeline, extracting a near-surface current density abnormal change sequence, and generating a crack disturbance response characteristic diagram; And carrying out multi-source disturbance characteristic fusion discrimination on the abnormal magnetic field gradient change set and the near-surface current density abnormal change sequence, and outputting a defect distribution result and a defect grade evaluation result of the hydrogen-doped pipeline.
2. The method for detecting the hydrogen-doped pipeline based on the eddy current and magnetic leakage composite detection according to claim 1, wherein the step of obtaining the reference magnetic field distribution vector and the reference electromagnetic induction response matrix of the hydrogen-doped pipeline in the complete state to construct a composite detection reference field model of the hydrogen-doped pipeline comprises the following steps: acquiring base material information, geometric parameters and material electromagnetic parameters of the hydrogen-doped pipeline in a complete state, axially establishing equidistant detection paths in the hydrogen-doped pipeline, dividing the equidistant detection paths to obtain an axial discrete detection unit set, and calculating the equivalent magnetic permeability of each axial discrete detection unit; Based on the set of the axial discrete detection units and the equivalent magnetic permeability of each axial discrete detection unit, calculating the reference magnetic induction intensity of each axial discrete detection unit in the complete state of the hydrogen-doped pipeline by combining the parameter of the magnetizing device and the lifting height of the probe, and generating a reference magnetic field distribution vector; Based on the axial discrete detection unit set and the equivalent magnetic permeability of each axial discrete detection unit, and combining the high-frequency excitation parameter and the detection coil parameter, calculating the standard skin depth and the reference induction voltage amplitude of each axial discrete detection unit under the complete state of the hydrogen-doped pipeline, and generating a reference electromagnetic induction response matrix; Based on the reference magnetic field distribution vector and the reference electromagnetic induction response matrix, excitation scanning of the complete state of the hydrogen-doped pipeline is executed, the composite reference response value of each axial discrete detection unit is calculated, and a composite detection reference field model comprising the reference magnetic field distribution vector and the reference electromagnetic induction response matrix is generated.
3. The method for detecting a hydrogen-doped pipeline based on eddy current and magnetic leakage composite detection according to claim 1, wherein the method for detecting a hydrogen-doped pipeline based on a composite detection reference field model is characterized by performing leakage magnetic field response collection and abnormal field reconstruction under defect disturbance of the hydrogen-doped pipeline, extracting an abnormal magnetic field gradient change set, and generating a defect induction magnetic field disturbance distribution map, and specifically comprises the following steps: Based on the reference magnetic field distribution vector and the axial discrete detection unit set, working parameters of the magnetizing device and the magnetic sensing unit are configured, and a constant magnetizing field is applied to the hydrogen-doped pipeline until the wall body of the hydrogen-doped pipeline enters a stable near-saturation magnetizing interval; Along the axial detection path of the hydrogen-doped pipeline, the magnetic sensitive sensing units are used for collecting axial, radial and tangential three-component magnetic leakage signals of each axial discrete detection unit, and the axial sampling positions corresponding to each sampling point are calculated by combining the detection propulsion speed and the sampling moment; Synthesizing to obtain the measured total magnetic leakage amplitude of each axial discrete detection unit based on the axial, radial and tangential three-component magnetic leakage signals of each axial discrete detection unit; Binding the measured total magnetic leakage amplitude of each axial discrete detection unit with the corresponding axial sampling position to form a measured magnetic leakage response sequence which is continuously arranged along the detection path.
4. The method for detecting the hydrogen-doped pipeline based on the eddy current and magnetic leakage composite detection according to claim 3, wherein the method is characterized in that based on a real magnetic leakage detection response sequence, the reference magnetic induction intensity corresponding to each axial discrete detection unit is called, the actual measurement-reference corresponding relation under the constraint of the same position and the same working condition is established, and the normalized abnormal offset value of each axial discrete detection unit is calculated by combining the disturbance parameters of the detection working condition; the calculation formula of the normalized abnormal offset value is as follows: ; in the formula, Normalized abnormal offset values for the ith axial discrete detection unit; the measured total magnetic flux leakage amplitude value of the ith axial discrete detection unit; The reference magnetic induction intensity is the ith axial discrete detection unit; the local calibration correction coefficient of the ith axial discrete detection unit is calculated; The actual lifting height between the magnetization module at the ith axial discrete detection unit and the outer surface of the hydrogen loading pipeline; the detection temperature of the ith axial discrete detection unit; The temperature is calibrated and detected; magnetizing current for the ith axial discrete detection unit; for calibrating magnetizing current; is a compensation coefficient; Setting a local sliding window based on the normalized abnormal offset value, and calculating the local offset ratio of each axial discrete detection unit; the calculation formula of the local offset ratio is as follows: ; in the formula, A local offset ratio for the ith axially discrete detection unit; A stability term to prevent denominator from being zero; The number of the axial discrete detection units in the local sliding window; in a local sliding window taking the ith axial discrete detection unit as the center, the sum of absolute values of normalized abnormal offset values of all the axial discrete detection units; Binding the normalized abnormal offset value of each axial discrete detection unit with the local offset ratio to generate an initial abnormal magnetic field offset sequence.
5. The method for detecting a hydrogen-doped pipeline based on eddy current and magnetic leakage composite detection according to claim 4, wherein the normalized abnormal offset values of the axial discrete detection units are ordered according to the axial position of the detection path based on the initial abnormal magnetic field offset sequence; calculating a first-order spatial gradient of the normalized abnormal offset value of each axial discrete detection unit by adopting a central difference method; Calculating a second-order spatial gradient of the normalized abnormal offset value of each axial discrete detection unit based on the first-order spatial gradient; and calculating the local gradient energy of each axial discrete detection unit by combining the normalized abnormal offset value, the corresponding first-order spatial gradient, the second-order spatial gradient and the detection step length, and generating a candidate abnormal field gradient set.
6. The method for detecting hydrogen-doped pipeline based on eddy current and magnetic leakage composite detection according to claim 5, wherein a candidate abnormal field gradient set is obtained, and abnormal sections are obtained based on local gradient energy screening; Performing smooth fitting and peak value searching on each abnormal section, determining position parameters of the abnormal section, calculating comprehensive abnormal strength of the abnormal section by combining local gradient energy of each axial discrete detection unit in the abnormal section, and screening to obtain a defect induction magnetic field disturbance region; The calculation formula of the comprehensive abnormal strength is as follows: ; in the formula, The combined anomaly intensity for the kth anomaly section; The number of axial discrete detection units contained for the kth abnormal section; Local gradient energy for the ith axial discrete detection unit; the axial position of the ith axial discrete detection unit in the abnormal section; is the center position of the kth abnormal section; Equivalent width of the kth abnormal section; Mapping all defect-induced magnetic field disturbance areas to a hydrogen-doped pipeline surface coordinate system to generate an abnormal magnetic field gradient change set and a defect-induced magnetic field disturbance distribution map.
7. The method for detecting a hydrogen-doped pipeline based on eddy current and magnetic leakage composite detection according to claim 1, wherein the method for detecting a hydrogen-doped pipeline based on a composite detection reference field model is characterized by executing eddy current response disturbance recognition induced by micro cracks on the near surface of the hydrogen-doped pipeline, extracting a near surface current density abnormal change sequence, and generating a crack disturbance response characteristic diagram, and specifically comprises the following steps: Based on a reference electromagnetic induction response matrix and an axial discrete detection unit set, configuring high-frequency electromagnetic excitation parameters and detection coil parameters, applying high-frequency alternating electromagnetic excitation to the hydrogen-doped pipeline along a detection path, and forming skin-seeking layer induction current on the near surface of the hydrogen-doped pipeline; Synchronously collecting the actual measurement equivalent resistance and the actual measurement equivalent inductance of each axial discrete detection unit, calculating the standard skin depth and the actual measurement equivalent impedance amplitude of each axial discrete detection unit, and establishing an actual measurement eddy current complex response sequence in which the actual measurement equivalent impedance amplitude corresponds to the reference electromagnetic induction response matrix one by one; based on the standard skin depth and the actually measured equivalent impedance amplitude, inverting and calculating the actual induction current density of each axial discrete detection unit, and generating a comparison sequence of the actual induction current density and the reference current density; the calculation formula of the actual induced current density is as follows: ; in the formula, The actual induced current density of the ith axial discrete detection unit; the measured equivalent impedance amplitude value is the ith axial discrete detection unit; The measured induced voltage amplitude is the ith axial discrete detection unit; Is the equivalent radius of the detection coil; The standard skin depth of the ith axial discrete detection unit; The measured phase lag is the i-th axial discrete detection unit; is the actual lift-off height of the magnetization module at the ith axial discrete detection unit from the outer surface of the loading tube.
8. The method for detecting a hydrogen-doped pipeline based on eddy current and magnetic leakage composite detection according to claim 7, wherein a normalized current density offset value and corresponding first-order spatial gradient and second-order spatial gradient are calculated for each axial discrete detection unit based on a comparison sequence of actual induced current density and reference current density in combination with a detection condition disturbance parameter; Calculating local abnormal energy of each axial discrete detection unit by combining the normalized current density offset value and the corresponding first-order spatial gradient and second-order spatial gradient, and screening to obtain candidate crack areas; And (3) obtaining the comprehensive crack strength of each candidate crack region, screening to obtain a near-surface crack disturbance region, mapping the near-surface crack disturbance region to a hydrogen-doped pipeline surface coordinate system, and generating a near-surface current density abnormal change sequence and a crack disturbance response characteristic diagram.
9. The method for detecting a hydrogen-doped pipeline based on eddy current and magnetic leakage composite detection according to claim 1, wherein the method for carrying out multi-source disturbance characteristic fusion discrimination on the abnormal magnetic field gradient change set and the near-surface current density abnormal change sequence and outputting a defect distribution result and a defect grade evaluation result of the hydrogen-doped pipeline specifically comprises the following steps: acquiring an abnormal magnetic field gradient change set and a near-surface current density abnormal change sequence, and establishing a unified coordinate system taking a detection starting point as an axial zero point and the accumulated displacement of an encoder as an axial reference; Mapping the magnetic leakage abnormal region and the eddy current abnormal region to a unified coordinate system, and calculating the axial overlapping ratio of each group of magnetic leakage abnormal region and the eddy current abnormal region; calculating the center offset distance between each group of magnetic flux leakage abnormal region and the eddy current abnormal region, and screening by combining the axial overlap ratio to obtain a composite defect alignment set; Aiming at each group of composite defect areas in the composite defect alignment set, calculating a disturbance consistency coefficient and a composite reliability value by combining an axial overlap ratio and a center offset distance to generate a composite defect reliability sequence; The calculation formula of the disturbance consistency coefficient is as follows: ; in the formula, The disturbance consistency coefficient of the o-th magnetic leakage abnormal region and the q-th eddy abnormal region is obtained; The axial overlap ratio of the (o) th magnetic leakage abnormal region and the (q) th eddy current abnormal region is set; The center offset distance between the (o) th magnetic leakage abnormal region and the (q) th eddy current abnormal region is set; Offset the decay length for the center; The leakage flux normalized intensity of the o-th leakage flux abnormal region; Normalizing the intensity of the eddy current for the q-th eddy current abnormal area; A stability term to prevent denominator from being zero; The calculation formula of the composite credibility value is as follows: ; in the formula, Forming a composite reliability value of the composite defect for the o-th magnetic leakage abnormal region and the q-th eddy abnormal region; is a slope control coefficient; is the confidence break threshold.
10. The method for hydrogen-doped pipeline detection based on eddy current and magnetic leakage composite detection according to claim 9, wherein, based on the composite defect reliability sequence, for each group of composite defect areas, extracting corresponding magnetic leakage normalized intensity, eddy current normalized intensity, composite reliability value and axial influence length, and weighting and calculating the grade grading value of each group of composite defect areas; classifying and risk grading the composite defects based on the grade grading values to generate defect grade assessment results of the hydrogen-doped pipelines; and mapping the defect grade evaluation result to a hydrogen-loading pipeline surface coordinate system to generate a defect distribution result of the hydrogen-loading pipeline.

Description

Hydrogen-doped pipeline detection method based on eddy current and magnetic leakage composite detection Technical Field The invention relates to the technical field of hydrogen-doped pipeline detection, in particular to a hydrogen-doped pipeline detection method based on eddy current and magnetic leakage composite detection. Background The hydrogen-doped natural gas transportation is a core path for large-scale storage, transportation and absorption of hydrogen energy, and the high-pressure pipeline is a key carrier for transporting a hydrogen-doped medium. However, in the long-term service process of the hydrogen-doped pipeline, hydrogen molecules penetrate to cause hydrogen-induced damage to steel, so that composite defects of near-surface microcrack initiation and expansion and deep metal section loss coexist, and meanwhile, the corrosion process of the pipeline is accelerated, the fatigue crack propagation rate and failure risk of the pipeline are obviously improved, and the operation safety of the pipeline is directly threatened. In the existing pipeline nondestructive detection technology, single magnetic leakage detection has good effect of identifying deep wall thickness loss, but has insufficient sensitivity of detecting near-surface microcracks, single eddy current detection can accurately capture near-surface defects, but cannot effectively identify deep section loss, and full-coverage detection of full-scale defects of hydrogen-doped pipelines is difficult to realize. Meanwhile, the existing composite detection scheme lacks a unified reference field model, is easily influenced by working condition disturbance such as lift-off fluctuation, temperature drift, pipeline geometry and material state difference, is easy to misjudge and miss-judge, and cannot meet the requirements of integrity assessment and safe operation and maintenance of long-period service of the hydrogen-doped pipeline. Therefore, it is necessary to provide a method for detecting a hydrogen-doped pipeline based on the combined detection of eddy current and magnetic leakage. Disclosure of Invention In order to solve the technical problems, the invention provides a method for detecting a hydrogen-doped pipeline based on eddy current and magnetic leakage composite detection, which is used for solving the problems that the existing single detection means is difficult to consider the full-scale identification of the near-surface microcracks and the deep metal section loss of the hydrogen-doped pipeline, the composite detection lacks a unified reference, is easily disturbed by working conditions, and has insufficient defect identification accuracy and reliability. The invention provides a hydrogen-doped pipeline detection method based on eddy current and magnetic leakage composite detection, which comprises the following steps: acquiring a reference magnetic field distribution vector and a reference electromagnetic induction response matrix of the hydrogen-doped pipeline in a complete state, and constructing a composite detection reference field model of the hydrogen-doped pipeline; based on a composite detection reference field model, carrying out leakage magnetic field response acquisition and abnormal field reconstruction under defect disturbance of the hydrogen-doped pipeline, extracting an abnormal magnetic field gradient change set, and generating a defect induction magnetic field disturbance distribution map; Based on the composite detection reference field model, executing eddy current response disturbance recognition induced by the near-surface microcracks of the hydrogen-doped pipeline, extracting a near-surface current density abnormal change sequence, and generating a crack disturbance response characteristic diagram; And carrying out multi-source disturbance characteristic fusion discrimination on the abnormal magnetic field gradient change set and the near-surface current density abnormal change sequence, and outputting a defect distribution result and a defect grade evaluation result of the hydrogen-doped pipeline. Preferably, the step of obtaining the reference magnetic field distribution vector and the reference electromagnetic induction response matrix under the complete state of the hydrogen-doped pipeline and constructing a composite detection reference field model of the hydrogen-doped pipeline comprises the following steps: acquiring base material information, geometric parameters and material electromagnetic parameters of the hydrogen-doped pipeline in a complete state, axially establishing equidistant detection paths in the hydrogen-doped pipeline, dividing the equidistant detection paths to obtain an axial discrete detection unit set, and calculating the equivalent magnetic permeability of each axial discrete detection unit; Based on the set of the axial discrete detection units and the equivalent magnetic permeability of each axial discrete detection unit, calculating the reference magnetic induction intensity