A method for processing vortex detection signals in a tubular reactor

Abstract

A tubular reactor eddy current detection signal processing method, the method comprises: acquiring the eddy current signal of the jacket pipe side through the eddy current detection probe, and associating the eddy current signal with the detection position to construct an eddy current signal space sequence. Based on the eddy current signal space sequence, an equivalent background representation of the background eddy current response of the jacket pipe and the interlayer interface is constructed. According to the equivalent background representation, local anomaly analysis is performed on the eddy current signal space sequence to identify the eddy current abnormal response component corresponding to the inner pipe defect. From the eddy current abnormal response component, the eddy current abnormal response meeting the electromagnetic disturbance characteristics is screened to reconstruct the inner pipe defect characteristics. According to the inner pipe defect characteristics, it is judged whether the eddy current signal meets the inner pipe defect response condition, if yes, the corresponding inner pipe defect position and inner pipe defect information are output, through the layered equivalent representation, interface response separation and defect feature reconstruction of the eddy current detection signal, the stable extraction and reliable discrimination of the inner pipe layer real defect signal are realized.

Description

A method for processing eddy current detection signals in a tubular reactor Technical Field

[0001] This invention relates to the field of eddy current field analysis technology, and in particular to a method for processing eddy current detection signals in a tubular reactor. Background Technology

[0002] In a multi-layered composite pipe wall structure consisting of an inner tube alloy layer and a jacketed tube, because the two layers only form a tight bond without achieving complete metallurgical bonding, the interlayer interface constitutes an abrupt boundary in an electromagnetic sense. During propagation, eddy currents undergo significant spatial redistribution and morphological distortion. Under these conditions, the local eddy current disturbances caused by microcracks in the inner tube layer and the eddy current field redistribution caused by the interlayer interface itself exhibit highly similar and superimposed response characteristics at the signal level, making it difficult for the detection signal to form a stable and distinguishable defect characteristic pattern.

[0003] Currently, existing technical solutions for enhancing and determining the continuity of eddy current signals typically implicitly assume that the tested pipe wall can be equivalent to a single homogeneous conductor. They do not independently model or constrain the interface effects introduced by multi-layer structures. As a result, in the case of composite pipe walls, it is difficult to effectively distinguish between signal changes caused by real crack defects and eddy current distortions caused by the inherent electromagnetic boundaries of the structure, which leads to systematic uncertainty in the defect identification results.

[0004] In response, this invention provides a method for processing eddy current detection signals in a tubular reactor. By performing layered equivalent characterization, interface response separation, and defect feature reconstruction on the eddy current detection signal, it achieves stable extraction and reliable discrimination of the real defect signal of the inner tube layer. Summary of the Invention

[0005] This application provides a signal processing method for eddy current detection in tubular reactors, which solves the technical problem in the prior art that it is difficult to effectively distinguish between signal changes caused by real crack defects and eddy current distortions caused by the inherent electromagnetic boundaries of the structure in composite tube wall scenarios, thus leading to systematic uncertainty in defect identification results.

[0006] The present invention adopts the following technical solution.

[0007] The first aspect of this invention discloses a method for processing eddy current detection signals in a tubular reactor, the method comprising:

[0008] Eddy current signals are acquired on the jacket side using an eddy current detection probe, and the eddy current signals are correlated with the detection position to construct a spatial sequence of eddy current signals.

[0009] Based on the spatial sequence of the eddy current signal, an equivalent background characterization of the response of the jacketed tube and the interlayer interface to the background eddy current is constructed.

[0010] Based on the equivalent background characterization, local anomaly analysis is performed on the spatial sequence of the eddy current signal to identify the eddy current anomaly response component corresponding to the inner tube defect.

[0011] Eddy current anomaly responses that conform to electromagnetic disturbance characteristics are selected from the eddy current anomaly response components to reconstruct the inner tube defect characteristics.

[0012] Based on the characteristics of the inner tube defect, determine whether the eddy current signal meets the inner tube defect response condition. If so, output the corresponding inner tube defect location and inner tube defect information.

[0013] Furthermore, the step of acquiring eddy current signals on the jacket side using an eddy current detection probe and correlating the eddy current signals with the detection position to construct an eddy current signal spatial sequence includes:

[0014] A jacketed tube detection coordinate system is established on the surface of the jacketed tube, and the scanning path is determined according to the jacketed tube detection coordinate system. At the same time, the sampling period of the eddy current signal and multiple sampling points on the side of the jacketed tube are set.

[0015] Based on the scanning path, the set sampling period, and multiple sampling points, the eddy current detection probe is placed on the surface of the jacket tube to obtain an initial eddy current signal sequence with timestamps.

[0016] The initial eddy current signal sequence includes the eddy current amplitude component and the eddy current phase component corresponding to each sampling time.

[0017] Furthermore, the step of acquiring eddy current signals on the jacket side using an eddy current detection probe and correlating the eddy current signals with the detection position to construct an eddy current signal spatial sequence further includes:

[0018] A baseline window is selected from the initial eddy current signal sequence, and the baseline intensity within the baseline window is calculated. The initial eddy current signal sequence is then normalized based on the baseline intensity to obtain a baseline-corrected eddy current signal sequence.

[0019] The scanning path is discretized into multiple detection positions, and the detection positions are aligned with timestamps. Multiple sampling points at the same detection position are aggregated to construct the spatial sequence of the eddy current signal.

[0020] Wherein, the baseline intensity is the average of the combined intensity of the eddy current amplitude component and the eddy current phase component within the baseline window.

[0021] Furthermore, the construction of an equivalent background characterization of the jacketed tube and interlayer interface response to background eddy currents based on the spatial sequence of the eddy current signal includes:

[0022] The spatial sequence of the eddy current signal is expanded into a monotonic position sequence according to the scanning path, and the monotonic position sequence is segmented according to the set background window length, while overlapping segments are set between adjacent background windows.

[0023] Calculate the steady-state representative value and signal fluctuation degree corresponding to the aggregated eddy current signal in each background window, and determine the background eddy current response candidate quantity and the steady-state score corresponding to the background eddy current response candidate quantity based on the steady-state representative value and signal fluctuation degree.

[0024] When the steady-state score exceeds a set threshold, the corresponding background window is retained as a background anchor point, and the background anchor points are sorted according to the center position of the window so as to output the equivalent background representation through piecewise continuity interpolation.

[0025] Furthermore, the step of performing local anomaly analysis on the eddy current signal spatial sequence based on the equivalent background characterization to identify the eddy current anomaly response component corresponding to the inner tube defect includes:

[0026] The eddy current signal spatial sequence is canceled by the equivalent background characterization to obtain an abnormal residual signal dominated by local anomalies, and a local analysis window is constructed for the detection position corresponding to the abnormal residual signal.

[0027] Calculate the mean and fluctuation of the abnormal residuals within the local analysis window, and calculate the local concentration score based on the mean and fluctuation of the abnormal residuals. Then, select abnormal candidate points based on the comparison results between the local concentration score and the set minimum residual threshold.

[0028] Furthermore, the step of performing local anomaly analysis on the eddy current signal spatial sequence based on the equivalent background characterization to identify the eddy current anomaly response component corresponding to the inner tube defect further includes:

[0029] Abnormal candidate points with adjacent positions not exceeding a set gap are aggregated into the same abnormal segment, and the spatial width and energy of the abnormal segment are calculated to remove abnormal segments with a spatial width not less than the length of the background window. The energy of the abnormal segment is the sum of the squared values ​​of the abnormal residuals at all positions within the abnormal segment.

[0030] The abnormal segments are screened according to a preset separation strategy, and the consistency of the screened abnormal judgments is verified so as to determine the eddy current abnormal response component corresponding to the inner tube defect based on the abnormal segments that pass the consistency verification.

[0031] Furthermore, the step of filtering eddy current anomaly responses that conform to electromagnetic disturbance characteristics from the eddy current anomaly response components to reconstruct the inner tube defect characteristics includes:

[0032] According to the start and end positions corresponding to the abnormal segments, the aggregated eddy current signals within the abnormal segments and the position coordinates of the eddy current signals are extracted from the eddy current signal spatial sequence, and the background eddy current response corresponding to the abnormal segments is extracted from the equivalent background representation to construct an abnormal segment aligned data packet.

[0033] Based on the anomalous fragment aligned data packet, the background eddy current response is normalized by the anomalous residual signal to construct a relative deviation ratio, and the difference of the relative deviation ratio corresponding to the equidistant positions on both sides of the eddy current peak center point in the anomalous fragment is calculated to obtain the inward and outward consistency score corresponding to the anomalous fragment.

[0034] Abnormal segments with inward and outward consistency scores not lower than a set threshold are selected, and the inner tube defect features are reconstructed based on the maximum relative deviation ratio within the abnormal segments and the length of segments with relative deviation ratios exceeding the eddy current peak.

[0035] Furthermore, the step of determining whether the eddy current signal meets the inner tube defect response condition based on the inner tube defect characteristics, and if so, outputting the corresponding inner tube defect location and inner tube defect information, includes:

[0036] The inner tube defect features whose spacing within the jacketed tube detection coordinate system does not exceed a set threshold are merged into the same defect candidate unit, and the spatial concentration of the defect candidate unit is calculated, so as to construct the defect comprehensive score and defect level parameters corresponding to the defect candidate unit based on the spatial concentration.

[0037] When the comprehensive defect score reaches the set defect confirmation threshold, the defect candidate unit is determined to be an inner tube defect, and the defect level corresponding to the inner tube defect is divided according to the defect level parameter, while the confidence level label of the inner tube defect is introduced.

[0038] Wherein, the location of the inner tube defect is the spatial center position of the defect candidate unit in the jacket tube detection coordinate system, and the inner tube defect information is the defect level and confidence level label of the inner tube defect.

[0039] A second aspect of the present invention discloses a tubular reactor eddy current detection signal processing device for implementing the tubular reactor eddy current detection signal processing method according to any one of the first aspects, the device comprising:

[0040] The eddy current space construction module is used to acquire eddy current signals on the jacket side through an eddy current detection probe and associate the eddy current signals with the detection position to construct a spatial sequence of eddy current signals.

[0041] The background eddy current characterization module is used to construct an equivalent background characterization of the response of the jacketed tube and the interlayer interface to the background eddy current based on the spatial sequence of the eddy current signal.

[0042] The eddy current anomaly identification module is used to perform local anomaly analysis on the spatial sequence of the eddy current signal based on the equivalent background characterization, so as to identify the eddy current anomaly response component corresponding to the inner tube defect.

[0043] The inner tube defect reconstruction module is used to filter out eddy current abnormal responses that conform to electromagnetic disturbance characteristics from the eddy current abnormal response components in order to reconstruct the inner tube defect characteristics.

[0044] The inner tube defect determination module is used to determine whether the eddy current signal meets the inner tube defect response conditions based on the inner tube defect characteristics. If so, it outputs the corresponding inner tube defect location and inner tube defect information.

[0045] A third aspect of the present invention discloses a terminal, including a processor and a storage medium;

[0046] The storage medium is used to store instructions;

[0047] The processor is configured to operate according to the instructions to perform the steps of the method described in the first aspect.

[0048] A fourth aspect of the present invention discloses a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect.

[0049] Compared with the prior art, this application has the following advantages:

[0050] (1) This invention involves placing an eddy current detection probe on the outer surface of the jacketed tube during operation or shutdown testing of a tubular reactor to collect eddy current detection signals. The collected signals are then synchronously correlated with the actual detection position of the probe on the surface of the jacketed tube to form a spatial sequence of eddy current signals reflecting the comprehensive electromagnetic response of the jacketed tube, interlayer interface, and inner tube. Subsequently, the continuous variation characteristics of the eddy current signals on a large spatial scale are analyzed to identify the background eddy current response dominated by the jacketed tube and interface, and a corresponding equivalent background characterization is constructed to describe the unavoidable structural electromagnetic influences under jacketed tube side testing conditions. This provides a reliable baseline for the abnormal separation of inner tube defects and lays the foundation for effectively distinguishing signal changes caused by real crack defects from eddy current distortions caused by the inherent electromagnetic boundaries of the structure.

[0051] (2) Based on the characterization of the eddy current background response of the jacketed tube and interface, this invention analyzes the local abnormal changes in the spatial sequence of eddy current signals, identifies abnormal response components that still exhibit local concentration and have a spatial scale significantly smaller than the background change scale under the detection conditions on the jacketed tube side, and regards the identified abnormal responses as eddy current disturbances that may be caused by local defects in the inner tube, thus achieving the initial separation of eddy current responses related to inner tube defects. Subsequently, the spatial distribution characteristics, intensity variation law, and relative relationship with the background response of the eddy current response in the jacketed tube detection coordinate system are further analyzed. Abnormal responses that conform to the electromagnetic disturbance characteristics transmitted from the inside to the outside are retained, and pseudo-anomalies caused by the surface state of the jacketed tube or uneven interlayer bonding are suppressed. Thus, the eddy current signal feature description dominated by the real defects in the inner tube is reconstructed, which can effectively distinguish the signal changes caused by real crack defects from the eddy current distortion caused by the inherent electromagnetic boundary of the structure, further improving the accuracy of defect identification results. Attached Figure Description

[0052] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0053] Figure 1 is a schematic flowchart of a tubular reactor eddy current detection signal processing method provided by the present invention.

[0054] Figure 2 is a schematic diagram of the structure of a tubular reactor eddy current detection signal processing device provided by the present invention.

[0055] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0056] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0057] As shown in Figure 1, in one embodiment, a method for processing eddy current detection signals in a tubular reactor includes the following steps:

[0058] Step S110: Obtain eddy current signals from the jacketed tube side using an eddy current detection probe, and associate the eddy current signals with the detection position to construct a spatial sequence of eddy current signals.

[0059] In some embodiments, the eddy current detection signal processing method for a tubular reactor provided by the present invention includes the following steps in step S110:

[0060] Step S111: Establish a jacketed tube detection coordinate system on the surface of the jacketed tube, determine the scanning path according to the jacketed tube detection coordinate system, and set the sampling period of the eddy current signal and multiple sampling points on the side of the jacketed tube.

[0061] Step S112: Based on the scanning path, the set sampling period, and multiple sampling points, the eddy current detection probe is placed on the surface of the jacket tube to obtain an initial eddy current signal sequence with timestamps.

[0062] The initial eddy current signal sequence contains the eddy current amplitude component and the eddy current phase component corresponding to each sampling time.

[0063] In some embodiments, the eddy current detection signal processing method for a tubular reactor provided by the present invention further includes the following steps in step S110:

[0064] Step S113: Select a baseline window from the initial eddy current signal sequence and calculate the corresponding baseline intensity within the baseline window. Perform amplitude normalization processing on the initial eddy current signal sequence based on the baseline intensity to obtain the baseline-corrected eddy current signal sequence.

[0065] Step S114: Discretize the scanning path into multiple detection positions, align the detection positions with timestamps, and aggregate multiple sampling points at the same detection position to construct a spatial sequence of eddy current signals.

[0066] The baseline intensity is the average of the combined intensity of the amplitude component and the phase component of the eddy current within the baseline window.

[0067] In a specific embodiment, the present invention provides a method for processing eddy current detection signals in a tubular reactor. This method addresses the technical problem that, when a tubular reactor employs a multi-layered composite tube wall structure consisting of an inner tube alloy layer and a jacketed tube, the electromagnetic boundary abrupt change introduced at the non-metallurgical interface between the layers leads to a high degree of coupling and difficulty in distinguishing between the actual defect response and the inherent eddy current distortion in the eddy current detection signal. The method achieves stable extraction and reliable discrimination of the actual defect signal of the inner tube layer by performing layered equivalent characterization, interface response separation, and defect feature reconstruction on the eddy current detection signal. The method includes steps 1 to 5:

[0068] Step 1: Synchronous acquisition and spatial correlation construction of eddy current detection signals on the jacketed tube side.

[0069] During operation or shutdown testing of the tubular reactor, an eddy current detection probe is placed on the outer surface of the jacketed tube, and eddy current detection signals are acquired by scanning along the axial or circumferential direction of the tube. The acquired signals are then synchronously correlated with the actual detection position of the probe on the surface of the jacketed tube to form a spatial sequence of eddy current signals reflecting the comprehensive electromagnetic response of the jacketed tube, interlayer interface, and inner tube. This includes the following sub-steps:

[0070] Sub-step 1.1: Setting the eddy current detection conditions and scanning reference for the jacketed tube side.

[0071] Specifically, a unified detection coordinate system for the jacketed tube is established on the outer surface of the jacketed tube. The tube axis is used as the axial reference, and the circumferential unfolding angle of the jacketed tube is used as the circumferential reference. The scanning path is determined to be either axial scanning or circumferential scanning, or a combination of both. For axial scanning, the scanning step size is set to a fixed value and limited to an achievable engineering range, ranging from 0.5 to 5 mm, to balance the spatial resolution of defect response and scanning efficiency. For circumferential scanning, the circumferential angular step size is set, ranging from 0.5 to 5 degrees. The sampling period is determined by the sampling frequency and scanning speed of the data acquisition hardware, requiring multiple sampling points to be obtained within any scanning step size to ensure the formation of a continuous signal sequence. Simultaneously, to ensure the alignment of detection results from different batches, a physically repeatable reference marker is selected on the surface of the jacketed tube as the zero point before each detection begins, and the axial coordinates and circumferential angle of the reference marker are recorded as a global reference.

[0072] Sub-step 1.2: The eddy current excitation on the jacket side is synchronously acquired with the original signal.

[0073] Specifically, the eddy current detection probe is positioned on the outer surface of the jacketed tube, and the probe's orientation and coupling state are kept consistent and stable during the scanning process. When synchronously acquiring the eddy current detection signal, the original amplitude and phase at each sampling moment are combined into an original sampling point, and a timestamp of the same moment is appended to this original sampling point. To enable subsequent amplitude consistency processing and energy quantization, the original sampling point needs to be converted into a unified expression of amplitude and phase scalars, and the composite intensity index of the sampling point is calculated. Finally, the original eddy current signal sequence from the jacketed tube side, carrying a timestamp, is output.

[0074] Among them, the composite strength index is used to uniformly characterize the amplitude and phase on a single engineering quantity, which facilitates the subsequent establishment of a spatial sequence. The expression is:

[0075] ;

[0076] In the formula, for The composite intensity index at any given time is expressed in normalized units based on the detection output. for The eddy current amplitude components acquired at all times originate from the amplitude channel output of the acquisition instrument; for The eddy current phase component at any given time originates from the phase channel output of the data acquisition instrument; This is a phase reference value used to convert the phase difference into a relative change, and its value is the average value of the phase within the starting segment of the current detection. This is the phase weighting coefficient, used to adjust the contribution of the phase difference to the composite intensity, with a value range of 0.1-10.

[0077] Sub-step 1.3: Baseline correction and amplitude consistency processing of sampling points on the jacket side.

[0078] Specifically, due to slight changes in coupling state and differences in the surface state of the jacket tube during side detection, amplitude consistency processing is required to avoid overall drift during subsequent spatial correlation. First, a stable region at the start of the detection is selected as the baseline window. The average value of the composite intensity index within this window is calculated as the baseline intensity. The original eddy current signal sequence is then subjected to baseline subtraction and amplitude normalization to obtain a dimensionless standardized intensity sequence. Finally, the baseline-corrected eddy current signal sequence is output, ensuring that signals from different scanning sections are at comparable amplitude benchmarks.

[0079] Sub-step 1.4: Synchronous correlation between the jacket position and the eddy current signal and generation of the spatial sequence.

[0080] Specifically, the scanning process is discretized into several location points, each assigned a spatial location number, and aligned with the sampling timestamp. For axial scanning, the axial position of the jacket is obtained by summing the axial coordinates of the scanning start point and the step distance; for circumferential scanning, the circumferential angular position is obtained by summing the circumferential zero point and the angular step distance. Subsequently, multiple sampling points within the same location number are aggregated to obtain the representative signal value for that location. The aggregation method uses a weighted combination of the mean and peak value, which preserves the spike response caused by local defects while preventing occasional fluctuations from completely dominating the result.

[0081] Sub-step 1.5: Spatial sequence integrity verification and output solidification.

[0082] Specifically, the spatial sequence undergoes integrity verification, including checking the continuity of location points, the presence of missing segments, and the presence of abnormally saturated segments in the aggregated signal. If missing segments are found, their spatial numbers are recalculated based on the scanning baseline and marked as segments to be scanned again. If abnormally saturated segments are found, they are marked as segments with coupling anomalies or probe out-of-plane risks, so that they can be masked during subsequent modeling and separation. Finally, the spatial sequence is fixed and saved in a fixed field order, including the axial position of the jacket tube, the circumferential angular position of the jacket tube, the aggregated signal value, and the quality marker.

[0083] Step S120: Based on the spatial sequence of eddy current signals, construct an equivalent background characterization of the response of the jacketed tube and the interlayer interface to the background eddy current.

[0084] In some embodiments, the eddy current detection signal processing method for a tubular reactor provided by the present invention includes the following steps in step S120:

[0085] Step S121: Expand the eddy current signal spatial sequence into a monotonic position sequence according to the scanning path, segment the monotonic position sequence according to the set background window length, and set overlapping segments between adjacent background windows.

[0086] Step S122: Calculate the steady-state representative value and signal fluctuation degree corresponding to the aggregated eddy current signal in each background window, and determine the background eddy current response candidate quantity and the steady-state score corresponding to the background eddy current response candidate quantity based on the steady-state representative value and signal fluctuation degree.

[0087] Step S123: When the steady-state score exceeds the set threshold, the corresponding background window is retained as the background anchor point, and the background anchor points are sorted according to the center position of the window so as to output the equivalent background representation through piecewise continuity interpolation.

[0088] In a specific embodiment, the present invention provides a method for processing eddy current detection signals in a tubular reactor. Step 2 involves the equivalent background characterization of the eddy current response to the jacketed tube and interlayer interface. For the spatial sequence of eddy current signals output in Step 1, the continuous variation characteristics of the signals on a large spatial scale are analyzed. The stable response generated by the geometry, material properties, and interlayer bonding state of the jacketed tube is identified as the background eddy current response dominated by the jacketed tube and interface. A corresponding equivalent background characterization is constructed to describe the unavoidable structural electromagnetic influences under jacketed tube-side detection conditions, including the following sub-steps:

[0089] Sub-step 2.1: Construction of a large-scale continuity window for the spatial sequence on the jacket side.

[0090] Specifically, the spatial sequence is expanded into a monotonic position number sequence along the scanning path, and the position numbers are segmented with a fixed background window length. The recommended range for this background window length is 20-200 position points. This ensures that the spatial scale covered by the window is significantly larger than the spatial scale of the typical defect response, thus allowing the dominant changes within the window to originate primarily from the geometry of the jacketed tube, material properties, or interlayer bonding. Subsequently, to avoid the window boundaries unilaterally cutting off the continuous structural response, overlapping sections are set between adjacent windows, with an overlap ratio ranging from 10% to 50%. Simultaneously, the center position number of each window is recorded for use in defining and interpolating the background curve.

[0091] Sub-step 2.2: Extraction of candidate background responses within the window and construction of steady-state criteria.

[0092] Specifically, for each background window, the steady-state representative value and fluctuation degree of the aggregated signal within the window are calculated. Based on the steady-state representative value and the fluctuation degree of the aggregated signal within the window, it is determined whether the background window is suitable as a candidate sample for the background response of the jacket tube and interface. The steady-state representative value is obtained by fusing the mean and median to reduce the interference of a few local anomalies within the window on the representative value; the fluctuation degree of the window is obtained by variance normalization to characterize whether the background is smooth. Then, a steady-state score is introduced to filter out background windows that obviously contain local anomalies, so that the background candidate quantity reflects only the jacket tube and interface effects as much as possible.

[0093] In this embodiment, the expression for the steady-state representative value is:

[0094] ;

[0095] In the formula, For the first The steady-state representative value of each background window is used as a background candidate value; For the first The average value of the aggregated signal within each background window; For the first The median of the aggregated signal values ​​within each background window; This is the mean weighting coefficient, with a value ranging from 0.4 to 0.8, used to balance the average trend and the ability to resist anomalies.

[0096] The expression for the degree of window fluctuation is:

[0097] ;

[0098] In the formula, For the first The normalized window fluctuation of each background window; For the first The variance of the aggregated signal values ​​within each background window; To stabilize the term and prevent the denominator from being too small and causing an amplification effect, the value range is 0.001-0.1.

[0099] Finally, the window steady-state score can be determined based on the degree of window fluctuation, expressed as:

[0100] ;

[0101] In the formula, For the first The window stability score of each background window ranges from 0 to 1, with a larger value indicating a more stable state.

[0102] Sub-step 2.3: Construction and continuous output of the equivalent background curve of the jacketed tube and interface.

[0103] Specifically, background windows are selected based on steady-state scores. When a steady-state score exceeds a preset threshold, the background window is retained as a background anchor point. This preset threshold ranges from 0.6 to 0.9. Next, the retained background anchor points are sorted by their center position numbers within their background windows, and piecewise continuous interpolation is used to construct a background curve covering the entire scan path, ensuring that each jacket tube location receives a corresponding background response value. Furthermore, to prevent the background curve from excessively following local fluctuations, a maximum rate of change constraint is set on the variation amplitude of adjacent background anchor points during interpolation, ensuring slow and continuous background changes. The recommended maximum rate of change is within the range of 0.05-0.5 normalized units per 10 locations. Finally, the background curve is output as a combination of location numbers and background values, aligned with the spatial sequence output in step 1, forming an equivalent background representation that can be directly used.

[0104] Specifically, when the window stability score of a background window is greater than or equal to a set threshold, the background anchor point of the background window is marked with a value of 1; otherwise, it is marked with a value of 0.

[0105] Sub-step 2.4: Background characterization quality verification and referenceable output solidification.

[0106] Specifically, the background characterization undergoes quality verification, including three checks:

[0107] (1) Whether the background curve is spatially continuous and without breaks. If there are breaks, backtrack to sub-step 2.1 to expand the overlap window ratio and regenerate the anchor points;

[0108] (2) Whether the background curve shows unreasonable high-frequency jitter. If it fluctuates greatly repeatedly within a small number of adjacent positions, it indicates that the anchor point screening threshold is too low or the maximum rate of change constraint is too wide. It is necessary to increase the steady-state threshold or tighten the maximum rate of change.

[0109] (3) Whether the background curve is too flat, which makes it impossible to reflect the slow changes in the geometry or bonding state of the jacket tube. If the overall change is less than the expected minimum amplitude threshold, it means that the background window length is too large, resulting in loss of details, and the background window length needs to be reduced.

[0110] Finally, after the verification is passed, the background representation is solidified and output. The solidified fields include the location number, background response value, anchor mark, and verification mark.

[0111] Step S130: Perform local anomaly analysis on the spatial sequence of eddy current signals based on the equivalent background characterization to identify the eddy current anomaly response components corresponding to the inner tube defects.

[0112] In some embodiments, the eddy current detection signal processing method for a tubular reactor provided by the present invention includes the following steps in step S130:

[0113] Step S131: The spatial sequence of eddy current signals is canceled by equivalent background characterization to obtain the abnormal residual signal dominated by local anomalies, and a local analysis window is constructed for the detection position corresponding to the abnormal residual signal.

[0114] Step S132: Calculate the mean and fluctuation of the abnormal residuals within the local analysis window, and calculate the local concentration score based on the mean and fluctuation of the abnormal residuals. Then, select abnormal candidate points based on the comparison results between the local concentration score and the set minimum residual threshold.

[0115] In some embodiments, the eddy current detection signal processing method for a tubular reactor provided by the present invention further includes the following steps in step S130:

[0116] Step S133: Aggregate the abnormal candidate points with adjacent positions not exceeding the set gap into the same abnormal segment, and calculate the spatial width and energy of the abnormal segment to remove abnormal segments with a spatial width not less than the length of the background window. The energy of the abnormal segment is the sum of the squared values ​​of the abnormal residuals at all positions within the abnormal segment.

[0117] Step S134: The abnormal segments are screened according to the preset separation strategy, and the consistency of the screened abnormal judgments is checked, so as to determine the eddy current abnormal response component corresponding to the inner tube defect based on the abnormal segments that pass the consistency check.

[0118] In a specific embodiment, the present invention provides a method for processing eddy current detection signals in a tubular reactor. Step 3 involves separating the eddy current anomaly response to defects in the inner tube. Based on the characterization of the eddy current background response of the jacketed tube and interface obtained in step 2, local anomaly changes in the spatial sequence of the eddy current signal are analyzed. Anomaly response components that still exhibit local concentration and have a spatial scale significantly smaller than the background change scale under the detection conditions on the jacketed tube side are identified. These anomaly responses are considered to be eddy current disturbances possibly caused by local defects in the inner tube, thereby achieving preliminary separation of the eddy current response related to inner tube defects. This includes the following sub-steps:

[0119] Sub-step 3.1: Construction of the abnormal residual signal after background cancellation.

[0120] Specifically, in the scenario of detecting defects in the inner tube on the jacketed tube side, the eddy current response caused by the interface between the jacketed tube and the interlayer exhibits a slow and continuous change, while the disturbance caused by the inner tube defect usually manifests as a localized concentrated change. Therefore, it is necessary to use background characterization to cancel the original spatial sequence to obtain an anomalous residual signal dominated by local anomalies. In addition, to reduce the uneven impact of residuals being masked when the background amplitude is large and amplified when the background amplitude is small, the anomalous residuals are expressed using a fusion of difference and proportion, so that the anomalous residuals reflect both absolute and relative deviations.

[0121] The expression for the abnormal residual is:

[0122] ;

[0123] In the formula, For the first The abnormal residuals at each jacketed pipe location point are dimensionless quantities. For the first Aggregated signal values ​​at each jacket tube location point; For the first Background response values ​​at each jacketed pipe location point.

[0124] Sub-step 3.2, Local concentration measurement and screening of outlier candidate points.

[0125] Specifically, when defects in the inner tube are transmitted to the detection end of the jacketed tube, they typically manifest as a rapid increase and subsequent decrease in residuals over a short distance, i.e., local concentration. Therefore, a local analysis window needs to be constructed for each location point. The length of the analysis window should be significantly shorter than the aforementioned background window length, with a recommended range of 5-30 location points. For the residuals within the window, the degree of increase in the residual at that point relative to the average residual and window fluctuation is calculated to form a local concentration score. This score is then combined with a minimum residual threshold to screen for abnormal candidate points. Simultaneously, to avoid mistaking occasional single-point spikes for defects, the local concentration score and residual intensity of the candidate points must both reach a set threshold.

[0126] The expression for the local concentration score is as follows:

[0127] ;

[0128] In the formula, For the first Local concentration score of each jacketed pipe location point; For the first The average value of the absolute value of the residuals within the local window at the center of each jacket location point is used to characterize the local background level. It is the standard deviation of the absolute values ​​of the residuals within the same local window, used to characterize the scale of local fluctuations.

[0129] In this embodiment, during the screening of anomalous candidate points, if the absolute value of the anomalous residual is greater than or equal to a set residual intensity threshold (ranging from 0.2 to 3) and the local concentration score is greater than or equal to a set local concentration threshold (ranging from 1 to 5), then the anomalous candidate point is marked with a value of 1; otherwise, it is marked with a value of 0. The final output set of anomalous candidate points includes candidate location number, candidate residual intensity, and candidate local concentration score, which are used to subsequently form anomalous segments and determine whether their spatial scale is smaller than the background change scale.

[0130] Sub-step 3.3: Anomalous candidate points are aggregated into anomalous fragments and spatial scale is determined.

[0131] Specifically, the response to inner tube defects typically manifests as anomalies at several consecutive locations, rather than isolated single points. Therefore, candidate points with adjacent location numbers not exceeding a preset gap are aggregated into the same anomalous segment. This preset gap ranges from 1 to 3 location points to accommodate the continuity of the defect response under different scan steps. Then, for each anomalous segment, its spatial width and energy index are calculated to determine whether the corresponding anomalous segment belongs to anomalies whose spatial scale is significantly smaller than the background change scale. The spatial width is equal to the difference between the segment's start and end location numbers plus one; the energy index characterizes the overall perturbation intensity of the segment, calculated using the sum of squared residuals, emphasizing both peak value and spatial width. Subsequently, the segment width is compared with the background window length in step 2: if the segment width is much smaller than the background window length, the segment is more consistent with local perturbations caused by inner tube defects; if the segment width is close to or greater than the background scale, it is more likely a residual caused by slow changes in the jacketed tube or interface bonding state, and should be downweighted or eliminated.

[0132] Sub-step 3.4: Preliminary separation and output solidification of abnormal responses related to internal tube defects.

[0133] Specifically, a preliminary separation strategy based on scale priority, energy constraint, and morphological consistency is applied to the set of anomalous segments. First, segments are filtered by relative scale ratio, retaining those with a ratio less than a preset threshold (range 0.05-0.3) to ensure that the retained anomalous segments are significantly smaller than the background variation scale in spatial scale. Next, a minimum threshold is set for the energy index of the anomalous segments to avoid mistaking extremely small local fluctuations for defects. This minimum energy threshold ranges from 0.5-50 and is adjusted in conjunction with the scan step size and residual intensity threshold. Finally, a consistency check is performed on the morphology of the anomalous segments. The residuals within the anomalous segments are required to exhibit a single-peak pattern of rising, peaking, and falling near the peak point. Long plateaus or multiple repetitive peaks with large intervals are more likely to be complex responses caused by changes in interface adhesion and are marked as segments to be reviewed rather than directly output as defective segments. After separation, the retained anomalous segments and their position indices in the original spatial sequence are solidified and output to obtain a set of flow anomaly responses, including the start and end position numbers of the retained anomalous segments, the peak residual of the segments, the segment energy, the relative scale ratio of the segments, and the reference indices of the corresponding original aggregated signals and background signals. This facilitates subsequent fine-grained defect feature reconstruction by tracing back the original eddy current signals and equivalent background representations.

[0134] Step S140: Select eddy current abnormal responses that conform to the characteristics of electromagnetic disturbance from the eddy current abnormal response components in order to reconstruct the characteristics of the inner tube defect.

[0135] In some embodiments, the eddy current detection signal processing method for a tubular reactor provided by the present invention includes the following steps in step S140:

[0136] Step S141: Extract the aggregated eddy current signals and their position coordinates from the eddy current signal spatial sequence according to the start and end positions of the abnormal segments, and extract the background eddy current response corresponding to the abnormal segments from the equivalent background representation to construct an abnormal segment aligned data packet.

[0137] Step S142: Based on the abnormal segment alignment data packet, the background eddy current response is normalized by the abnormal residual signal to construct the relative deviation ratio, and the difference of the relative deviation ratio corresponding to the equidistant positions on both sides of the eddy current peak center point in the abnormal segment is calculated to obtain the inward and outward consistency score corresponding to the abnormal segment.

[0138] Step S143: Select abnormal segments with inward and outward consistency scores not lower than a set threshold, and reconstruct the inner tube defect features based on the maximum relative deviation ratio within the abnormal segments and the length of segments with relative deviation ratios exceeding the eddy current peak.

[0139] In a specific embodiment, the present invention provides a method for processing eddy current detection signals in a tubular reactor. Step 4 involves reconstructing the inner tube defect features based on the detection conditions on the jacketed tube side. For the eddy current anomaly response set obtained in step 3, the spatial distribution characteristics, intensity variation patterns, and relative relationship with the jacketed tube background response of the eddy current anomaly response in the jacketed tube detection coordinate system are further analyzed. Only anomaly responses conforming to the electromagnetic disturbance characteristics transmitted from the inside out are retained, while pseudo-anomalies caused by the surface condition of the jacketed tube or uneven interlayer bonding are suppressed. This reconstructs a description of eddy current signal features dominated by real inner tube defects, including the following sub-steps:

[0140] Sub-step 4.1: Align the abnormal fragment backtracking with the relative response on the jacket side.

[0141] Specifically, for each anomalous segment, the aggregated signal and corresponding position coordinates within the segment's coverage area are extracted back from the original spatial sequence according to its start and end position numbers. Simultaneously, the background response within the same range is extracted from the equivalent background representation, forming a point-by-point alignment sequence. Then, to facilitate comparison of the morphological consistency of different segments in the jacket-side detection coordinate system, the eddy current signal of each anomalous segment needs to be normalized and located using peak point alignment. During the normalization and location process, the point with the largest absolute value of the residual within the segment is determined as the peak center point. A fixed-length analysis interval is then expanded outwards from this point, with a recommended interval length of 5-50 position points to ensure complete coverage of the rise, peak, and fall processes. Finally, the output aligned data packet fields include the jacket position number, axial position, circumferential angle, aggregated signal, background response, anomalous residual, and peak center point number.

[0142] Sub-step 4.2: Pass the relative response consistency judgment from the inside out.

[0143] Specifically, when detecting defects in the inner tube on the jacketed tube side, the electromagnetic disturbance from the inner tube typically exhibits the following characteristics: the deviation from the background is strongest at the center of the segment and gradually decreases towards both sides, with a stable relative proportional relationship between the deviation and the background intensity. Changes in the surface condition of the jacketed tube (e.g., minor scratches on the outer surface, changes in oxide scale thickness) are more likely to cause local abrupt changes in the original polymerization signal, but the relative proportional relationship between this deviation and the background response is unstable and often accompanied by asymmetrical abrupt changes at the segment edges. Therefore, it is necessary to construct a relative deviation ratio sequence and evaluate its symmetry and attenuation within the segment. This relative deviation ratio uses the residual to renormalize the background amplitude, used to characterize the response intensity that can be compared across segments.

[0144] In the alignment coordinates of the abnormal segments, the relative deviation ratio difference between equidistant positions on both sides of the peak center point is calculated as the center of symmetry to form a symmetry loss. The smaller this symmetry loss, the more it conforms to the characteristics of propagation from the inside out and diffusion and attenuation to both sides. Finally, the formed symmetry loss is mapped to an inside-out consistency score to facilitate threshold determination and sorting. The inside-out consistency score sequence is output, including the inside-out consistency score and pass mark for each abnormal segment, to screen out false anomalies caused by changes in the surface condition of the jacket tube or uneven interlayer bonding.

[0145] Sub-step 4.3: False anomaly suppression and defect-dominant feature reconstruction.

[0146] Specifically, firstly, anomalies are filtered based on inside-out consistency scores, retaining those with scores no lower than a set threshold. This threshold ranges from 0.2 to 0.7, used to accommodate response differences under different jacket thicknesses and scanning step distances. Next, for the retained anomalies, their defect-dominant features are further engineered and reconstructed: the defect-dominant intensity is the maximum value of the relative deviation ratio within the segment; the defect-dominant width is the length of a continuous segment whose relative deviation ratio exceeds a certain proportion of the segment's peak value; and the defect-dominant energy is the sum of the squares of the relative deviation ratios, reflecting both intensity and range. Finally, to prevent pseudo-anomalies with extremely small residuals but accidentally good symmetry from passing the screening, dual constraints of intensity and energy lower limits are introduced. The intensity lower limit ranges from 0.2 to 3, and the energy lower limit ranges from 0.5 to 50. This results in the output of a reconstructed set of inner tube defect-dominant eddy current features, which outputs defect-dominant intensity, defect-dominant width, defect-dominant energy, and a defect confidence flag for each retained segment.

[0147] Sub-step 4.4: Solidify the feature set output and bind it to the traceable index.

[0148] Specifically, the features of each retained segment are fixedly output in a fixed field order and bound to a backtracking index, enabling subsequent steps to trace back from the feature set to the original aggregated signal and background response, and supporting engineering verification. Therefore, the final output fixed fields include the axial position of the jacket, the circumferential angular position of the jacket, the dominant defect intensity, the dominant defect width, the dominant defect energy, the inside-outside consistency score, the segment start and end position numbers, and the peak center point number. If the same spatial location is identified as a defect candidate in both the axial and circumferential scanning paths, the features of that spatial location are merged and marked to avoid duplicate counting.

[0149] Step S150: Determine whether the eddy current signal meets the inner tube defect response condition based on the inner tube defect characteristics. If so, output the corresponding inner tube defect location and inner tube defect information.

[0150] In some embodiments, the eddy current detection signal processing method for a tubular reactor provided by the present invention includes the following steps in step S150:

[0151] Step S151: Merge inner tube defect features with spacing not exceeding a set threshold within the jacketed tube detection coordinate system into the same defect candidate unit, and calculate the spatial concentration of the defect candidate unit to construct the defect comprehensive score and defect level parameters corresponding to the defect candidate unit based on the spatial concentration.

[0152] Step S152: When the comprehensive defect score reaches the set defect confirmation threshold, the defect candidate unit is determined to be an inner tube defect, and the defect level corresponding to the inner tube defect is divided according to the defect level parameter. At the same time, the confidence level label of the inner tube defect is introduced.

[0153] Among them, the inner tube defect location is the spatial center position of the defect candidate unit in the jacket tube detection coordinate system, and the inner tube defect information is the defect level and confidence level label of the inner tube defect.

[0154] In a specific embodiment, the present invention provides a method for processing eddy current detection signals in a tubular reactor. Step 5 involves determining and outputting inner tube defects under jacket-side detection conditions. Based on the eddy current signal feature set formed in step 4, the spatial concentration, stability, and relative intensity of abnormal features along the jacket-side detection path are comprehensively determined. When the inner tube defect response conditions are met, the corresponding inner tube defect location and defect severity information are output. This enables reliable detection of actual inner tube defects under conditions where eddy current detection can only be performed on the jacket-side. The method includes the following sub-steps:

[0155] Sub-step 5.1: Merge the defect candidate units of the feature set into spatial concentration calculations.

[0156] Specifically, firstly, candidates that are close together in the jacket tube coordinate system are merged into the same defect candidate unit. The merging radius ranges from 1 to 10 mm (axial distance) and 1 to 10 degrees (circumferential angular distance) to accommodate different scanning step distances and probe sizes. Then, for each candidate unit, its spatial concentration is calculated. This spatial concentration characterizes whether the defect response forms a stable, locally clustered aggregation along the jacket tube detection path. The spatial concentration is expressed as the ratio of the number of associated candidates to the diffusion radius; the more associated candidates and the smaller the diffusion radius, the higher the spatial concentration.

[0157] Sub-step 5.2: Construction of a joint score for stability and relative strength.

[0158] Specifically, under the jacketed tube side inspection conditions, a comprehensive score is constructed for each candidate unit. The score is jointly determined by spatial concentration, the dominant intensity of the largest defect within the candidate unit, and the average inside-out consistency score within the candidate unit. Simultaneously, a defect severity level parameter is constructed using a combination of defect dominant energy and intensity. Each weight in the combination is set as an adjustable constant to facilitate tuning under different jacketed tube thicknesses and inner tube materials. Then, the ratio of energy to peak intensity is used to reflect the extensibility of the defect response, distinguishing the performance differences between sharp, small defects and larger defects under the jacketed tube side inspection conditions, thus forming the defect severity level parameter.

[0159] Sub-step 5.3: Defect confirmation and judgment and result output.

[0160] Specifically, a defect confirmation threshold is set for each candidate unit. When the comprehensive defect score reaches the threshold, it is confirmed as an inner tube defect. The recommended threshold range is 1-20. Simultaneously, defect levels are classified according to a defect severity level parameter. For example, the defect level parameter falling into different intervals can be mapped to three levels: minor, moderate, and severe. The interval boundaries can be adjusted within the range of 0.1-10. The defect location is taken as the spatial center position of the corresponding candidate unit, and the axial and circumferential angular positions of the jacket tube are output as locatable coordinates on the jacket tube side. A confidence flag is included in the output, which is determined by the margin of the comprehensive defect score relative to the threshold, indicating the reliability of the output defect result.

[0161] In this embodiment, when the comprehensive defect score of a candidate unit is greater than or equal to the set defect confirmation threshold constant (the value range is 1-20), the candidate unit is marked as an inner tube defect with a value of 1, indicating that it is confirmed as an inner tube defect; otherwise, it is marked as a value of 0, indicating that it is not confirmed as an inner tube defect.

[0162] The present invention provides a tubular reactor eddy current detection signal processing device. The tubular reactor eddy current detection signal processing device described below and the tubular reactor eddy current detection signal processing method described above can be referred to in correspondence.

[0163] As shown in Figure 2, in one embodiment, a tubular reactor eddy current detection signal processing device includes an eddy current space construction module, a background eddy current characterization module, an eddy current anomaly identification module, an inner tube defect reconstruction module, and an inner tube defect determination module.

[0164] The eddy current space construction module is used to acquire eddy current signals on the jacket side through the eddy current detection probe and associate the eddy current signals with the detection position to construct a spatial sequence of eddy current signals.

[0165] The background eddy current characterization module is used to construct an equivalent background characterization of the jacketed tube and interlayer interface response to background eddy current based on the spatial sequence of eddy current signals.

[0166] The eddy current anomaly identification module is used to perform local anomaly analysis on the spatial sequence of eddy current signals based on the equivalent background characterization, so as to identify the eddy current anomaly response components corresponding to the inner tube defects.

[0167] The inner tube defect reconstruction module is used to filter out eddy current abnormal responses that conform to electromagnetic disturbance characteristics from the eddy current abnormal response components in order to reconstruct the inner tube defect characteristics.

[0168] The inner tube defect determination module is used to determine whether the eddy current signal meets the inner tube defect response conditions based on the inner tube defect characteristics. If so, it outputs the corresponding inner tube defect location and inner tube defect information.

[0169] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0170] It should be further noted that although the steps in the flowchart are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0171] It should be understood that the above-described device embodiments are merely illustrative, and the device of this application can also be implemented in other ways. For example, the division of units / modules in the above embodiments is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units, modules, or components may be combined, or integrated into another system, or some features may be ignored or not executed.

[0172] Furthermore, unless otherwise specified, the functional units / modules in the various embodiments of this application can be integrated into one unit / module, or each unit / module can exist physically separately, or two or more units / modules can be integrated together. The integrated units / modules described above can be implemented in hardware or as software program modules.

[0173] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0174] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0175] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A method for processing eddy current detection signals in a tubular reactor, characterized in that, The method includes: acquiring eddy current signals on the jacketed tube side using an eddy current detection probe, and associating the eddy current signals with the detection position to construct an eddy current signal spatial sequence; based on the eddy current signal spatial sequence, constructing an equivalent background characterization of the jacketed tube and interlayer interface response to background eddy currents; performing local anomaly analysis on the eddy current signal spatial sequence according to the equivalent background characterization to identify eddy current anomaly response components corresponding to inner tube defects; filtering eddy current anomaly responses that conform to electromagnetic disturbance characteristics from the eddy current anomaly response components to reconstruct inner tube defect characteristics; determining whether the eddy current signals meet the inner tube defect response conditions based on the inner tube defect characteristics, and if so, outputting the corresponding inner tube defect location and inner tube defect information; the step of acquiring eddy current signals on the jacketed tube side using an eddy current detection probe and associating the eddy current signals with the detection position to construct an eddy current signal spatial sequence includes: establishing a jacketed tube detection coordinate system on the surface of the jacketed tube, determining the scanning path according to the jacketed tube detection coordinate system, and simultaneously setting the sampling period of the eddy current signals and multiple sampling points on the jacketed tube side; based on the scanning path... The eddy current detection probe is placed on the surface of the jacket tube with a set sampling period and multiple sampling points to obtain an initial eddy current signal sequence with timestamps. The initial eddy current signal sequence includes eddy current amplitude and phase components corresponding to each sampling time. Based on the eddy current signal spatial sequence, an equivalent background characterization of the jacket tube and interlayer interface's response to background eddy currents is constructed, including: expanding the eddy current signal spatial sequence into a monotonic position sequence according to the scanning path, segmenting the monotonic position sequence according to a set background window length, and setting overlapping segments between adjacent background windows; calculating the steady-state representative value and signal fluctuation degree corresponding to the aggregated eddy current signal within each background window, and determining the candidate quantity of the background eddy current response between the jacket tube and interlayer interface and the steady-state score corresponding to the candidate quantity based on the steady-state representative value and signal fluctuation degree; retaining the corresponding background window as a background anchor point when the steady-state score exceeds a set threshold, and sorting the background anchor points according to the window center position to output the equivalent background characterization through piecewise continuous interpolation.

2. The method for processing eddy current detection signals in a tubular reactor according to claim 1, characterized in that, The step of acquiring eddy current signals from the jacket side via an eddy current detection probe and associating the eddy current signals with detection positions to construct an eddy current signal spatial sequence further includes: selecting a baseline window from the initial eddy current signal sequence and calculating the corresponding baseline intensity within the baseline window; performing amplitude normalization processing on the initial eddy current signal sequence based on the baseline intensity to obtain a baseline-corrected eddy current signal sequence; discretizing the scanning path into multiple detection positions and aligning the detection positions with timestamps; and aggregating multiple sampling points at the same detection position to construct the eddy current signal spatial sequence; wherein the baseline intensity is the average composite intensity of the eddy current amplitude component and the eddy current phase component within the baseline window.

3. The method for processing eddy current detection signals in a tubular reactor according to claim 1, characterized in that, The step of performing local anomaly analysis on the eddy current signal spatial sequence based on the equivalent background characterization to identify the eddy current anomaly response component corresponding to the inner tube defect includes: canceling the eddy current signal spatial sequence through the equivalent background characterization to obtain anomaly residual signals dominated by local anomalies, and constructing a local analysis window for the detection position corresponding to the anomaly residual signals; calculating the mean and fluctuation of the corresponding anomaly residuals within the local analysis window, and calculating a local concentration score based on the mean and fluctuation of the anomaly residuals, so as to screen out anomaly candidate points based on the comparison result of the local concentration score and a set minimum residual threshold.

4. The method for processing eddy current detection signals in a tubular reactor according to claim 3, characterized in that, The step of performing local anomaly analysis on the eddy current signal spatial sequence based on the equivalent background characterization to identify the eddy current anomaly response component corresponding to the inner tube defect further includes: aggregating anomaly candidate points with adjacent positions not exceeding a set gap into the same anomaly segment, and calculating the spatial width and energy of the anomaly segment to remove anomaly segments with a spatial width not less than the length of the background window, wherein the energy of the anomaly segment is the sum of the squared values ​​of the anomaly residuals at all positions within the anomaly segment; screening the anomaly segments according to a preset separation strategy, and performing consistency verification on the screened anomaly judgments to determine the eddy current anomaly response component corresponding to the inner tube defect based on the anomaly segments that pass the consistency verification.

5. The method for processing eddy current detection signals in a tubular reactor according to claim 4, characterized in that, The step of selecting eddy current anomaly responses conforming to electromagnetic disturbance characteristics from the eddy current anomaly response components to reconstruct the inner tube defect characteristics includes: extracting the aggregated eddy current signals and their position coordinates from the eddy current signal spatial sequence according to the start and end positions corresponding to the anomaly segments; extracting the background eddy current response corresponding to the anomaly segments from the equivalent background representation to construct anomaly segment alignment data packets; normalizing the background eddy current response using the anomaly residual signal based on the anomaly segment alignment data packets to construct a relative deviation ratio; calculating the difference in the relative deviation ratios corresponding to equidistant positions on both sides of the eddy current peak center point within the anomaly segment to obtain the inward and outward consistency score corresponding to the anomaly segment; selecting anomaly segments with inward and outward consistency scores not lower than a set threshold; and reconstructing the inner tube defect characteristics based on the maximum relative deviation ratio within the anomaly segments and segments with relative deviation ratios exceeding the length of the eddy current peak segments.

6. The method for processing eddy current detection signals in a tubular reactor according to claim 5, characterized in that, The step of determining whether the eddy current signal meets the inner tube defect response condition based on the inner tube defect characteristics, and outputting the corresponding inner tube defect location and inner tube defect information, includes: merging inner tube defect features with a spacing not exceeding a set threshold within the jacket tube detection coordinate system into the same defect candidate unit, and calculating the spatial concentration of the defect candidate unit to construct the defect comprehensive score and defect level parameter corresponding to the defect candidate unit based on the spatial concentration; when the defect comprehensive score reaches the set defect confirmation threshold, the defect candidate unit is determined to be an inner tube defect, and the defect level corresponding to the inner tube defect is divided according to the defect level parameter, while introducing the confidence mark of the inner tube defect; wherein, the inner tube defect location is the spatial center position of the defect candidate unit within the jacket tube detection coordinate system, and the inner tube defect information is the defect level and confidence mark of the inner tube defect.

7. A terminal, comprising a processor and a storage medium; characterized in that: The storage medium is used to store instructions; the processor is used to operate according to the instructions to perform the steps of the method according to any one of claims 1-6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method according to any one of claims 1-6.

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