Gas safety supervision system
By utilizing the Von Mises yield criterion and historical data tracing mechanism through the gas safety monitoring system, the corrosion types of gas pipelines can be identified, solving the problem of insufficient accuracy in corrosion monitoring in existing technologies and realizing the mechanistic and quantitative aspects of gas pipeline safety monitoring.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG JIUHAO INFORMATION TECHNOLOGY CO LTD
- Filing Date
- 2026-04-28
- Publication Date
- 2026-07-21
AI Technical Summary
In existing technologies, when judging abnormal corrosion of gas pipelines based on differential pressure data of the current monitoring period, the differential pressure change is not significant, which can easily lead to missed detection. Furthermore, the mutual influence effect of multiple corrosion defects is not considered, resulting in insufficient accuracy in gas safety supervision.
A gas safety monitoring system, including a calculation module, a matching module, and a monitoring module, is adopted. The remaining strength of the pipeline is calculated using the Von Mises yield criterion. Combined with the stress sequence and pipeline parameters in a three-dimensional coordinate system, the corrosion type is identified. Through a historical data tracing mechanism and difference threshold control, the equivalent quantification of multiple corrosion interactions is achieved.
It effectively identifies single and complex corrosion, avoids misjudgments, improves the accuracy and predictive ability of gas pipeline safety supervision, realizes mechanistic and quantitative supervision, and reduces computational complexity.
Smart Images
Figure CN122429327A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of data analysis technology, and more particularly to a gas safety monitoring system. Background Technology
[0002] In recent years, gas safety monitoring technology has developed rapidly. By combining vehicle-mounted laser detection systems with sniffer dogs, a new optical and biological collaborative technology can detect natural gas leaks up to 71 meters away from the vehicle's driving route. Miniature drones equipped with laser leak detectors can detect gas leaks in residential buildings through laser beams, achieving aerial sentinel patrols. A smart prediction method for urban gas pipeline leak diffusion based on PINN has been constructed. Combining pipeline leak diffusion patterns with data-driven models, high-precision leak concentration prediction is achieved. A closed-loop management system of perception, analysis, decision-making, and execution has been built. The gas pipeline network GIS system has been integrated to achieve precise equipment positioning and dynamic tracking.
[0003] Currently, Chinese invention patent CN120027365A discloses an intelligent gas pipeline differential pressure safety monitoring IoT system, method, and storage medium. This method determines the current gas pipeline network anomaly judgment result through a differential pressure data matrix. In response to the existence of an anomaly, it determines the anomaly probability distribution based on the differential pressure data matrix, generates an operation instruction set based on the anomaly probability distribution, and generates a pressure regulation instruction based on the differential pressure data matrix. The pressure regulation instruction is configured to control the pressure regulation equipment for pressure regulation. However, the related technology judges anomalies based on the differential pressure data of the current monitoring period. When corrosion enters the stable expansion stage, the differential pressure change may not be significant, which can easily lead to missed judgments. At the same time, it does not consider the mutual influence effect of multiple corrosion defects fusion and calculates corrosion parameters, which is not conducive to the accuracy of gas safety supervision and has certain limitations. Summary of the Invention
[0004] The technical problem solved by this invention is that in related technologies, anomalies are judged based on differential pressure data of the current monitoring cycle. When corrosion enters a stable expansion stage, the change in differential pressure may not be significant, which can easily lead to missed detection. At the same time, the mutual influence effect of multiple corrosion defects is not taken into account when calculating corrosion parameters, which is not conducive to the accuracy of gas safety supervision and has certain limitations.
[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a gas safety monitoring system, including a calculation module, a matching module, and a monitoring module; The calculation module calculates the remaining strength sequence of the pipeline based on the pipeline stress sequence; The remaining strength of the pipe was calculated using the Von Mises yield criterion formula. The matching module matches the corrosion type sequence and calculates the corrosion parameter sequence based on the pipeline's remaining strength sequence and pipeline parameters; Corrosion types include simple corrosion and complex corrosion; Corrosion parameters include axial length, circumferential width, and radial depth; The monitoring module determines whether the target pipeline needs maintenance based on the corrosion parameter sequence. If it does, it sends a maintenance signal; otherwise, it jumps to the next pipeline and repeats the logic of each module.
[0006] As a preferred embodiment of the gas safety monitoring system of the present invention, the pipeline stress sequence is a time series of stresses parallel to the coordinate axes obtained in a three-dimensional coordinate system constructed for the target pipeline. The pipeline stress sequence was acquired using stress sensors. Pipeline stress includes x-direction stress, y-direction stress, and z-direction stress, and pipeline stress is expressed as the internal pressure of the pipeline.
[0007] In a preferred embodiment of the gas safety monitoring system described in this invention, the expression for calculating the remaining strength of the pipeline is as follows: ; in, For the remaining strength of the pipe, For x-direction stress, For y-direction stress, The stress is in the z-direction.
[0008] As a preferred embodiment of the gas safety monitoring system of the present invention, a trigger condition is configured for the pipeline remaining strength sequence. When the trigger condition is not met, the pipeline remaining strength sequence is sent to the matching module. When the trigger condition is met, a new pipeline remaining strength sequence is set, and the first operation is performed according to the new pipeline remaining strength sequence. The trigger condition is defined as the change in the pipeline's remaining strength sequence being less than or equal to the first value; The first operation includes jumping to the next pipe and sending the new pipe's remaining strength sequence to the matching module; The calculation logic for the change includes obtaining the maximum and minimum values in the pipeline's remaining strength sequence, calculating the difference between the maximum and minimum values, and setting this difference as the change. The setting logic for the new pipeline residual strength sequence includes obtaining the total monitoring time of this pipeline residual strength sequence, selecting half of the total monitoring time value, and recording it as the search time; Based on the search duration, starting from the initial time point of this set of pipeline remaining strength sequences, the historical pipeline remaining strength sequences of the target pipeline are obtained in reverse chronological order. Arrange the historical pipeline residual strength sequence and this set of pipeline residual strength sequences in chronological order to obtain a new pipeline residual strength sequence.
[0009] As a preferred embodiment of the gas safety monitoring system of the present invention, the change amount corresponding to the new pipeline residual strength sequence is calculated based on the calculation logic of the change amount. Determine whether the change in the new pipeline remaining strength sequence meets the triggering condition. If yes, set the first operation to jump to the next pipeline. If no, set the first operation to send the new pipeline remaining strength sequence to the matching module.
[0010] As a preferred embodiment of the gas safety monitoring system of the present invention, the pipeline parameters include pipeline wall thickness and pipeline radius. The matching logic for corrosion type sequences includes: using a point-plotting method, drawing a curve of the pipeline's remaining strength sequence with a smooth curve; Identify the inflection points of the curve; Based on the inflection points of the curve, the curve is divided into N sub-graphs; Based on the pipeline parameters of the target pipeline, retrieve the standard corrosion curve corresponding to the pipeline parameters. Based on the shape feature extraction algorithm of machine vision, extract the first feature of any sub-image and extract the second feature of any standard corrosion curve. Calculate the cosine similarity between the first and second feature using the cosine similarity formula. Based on the comparison between cosine similarity and a preset similarity threshold, the erosion type corresponding to the sub-image is determined.
[0011] As a preferred embodiment of the gas safety monitoring system of the present invention, the inflection point identification logic of the curve includes obtaining the function expression of the curve through mathematical software, and taking the second derivative of the function expression of the curve to obtain the second derivative function. Find the zero of the second derivative and determine whether the product of the second derivative values on both sides of the zero is negative; If yes, then the x-coordinate corresponding to the zero point is determined as the x-coordinate of the inflection point; otherwise, the corresponding zero point is deleted. The subgraph segmentation logic includes selecting two inflection points that are adjacent in time sequence, selecting the median of the horizontal coordinates of these two inflection points, obtaining the point on the curve corresponding to the median, setting the point on the curve corresponding to the median as the cutting point, and drawing a cutting line parallel to the vertical axis through the cutting point. The curve is divided into sub-graphs based on the cutting lines.
[0012] As a preferred embodiment of the gas safety monitoring system of the present invention, the calculation logic of the corrosion parameter sequence includes: performing sequential calculations on the subgraphs according to the time sequence to obtain the corrosion parameter sequence corresponding to the subgraphs; When the corrosion type corresponding to the subgraph is single corrosion, the calculation logic of the corrosion parameters includes calculating the radial depth based on the pipe radius and the proportion of the z-direction stress in the sum of the stresses in each direction. Calculate the ratio of radial depth to pipe wall thickness, match the corresponding ultimate load based on the ratio of radial depth to pipe wall thickness, and obtain the standard load of the target pipe. Based on the ultimate load and standard load, the defect area is obtained, and based on the defect area and radial depth, the axial length is calculated. Calculate the circumferential width based on the pipe wall thickness, radial depth, and stress in all directions; When the corrosion type corresponding to the subgraph is complex corrosion, the calculation logic of the corrosion parameters includes calculating the corrosion parameters according to the calculation logic of the corrosion parameters when the corrosion type corresponding to the subgraph is single corrosion, and denoted as the comprehensive corrosion parameters. Obtain historical corrosion parameters corresponding to the target pipeline model. The historical corrosion parameters include historical axial length, historical radial depth, and historical circumferential width. Select any two historical corrosion parameters, calculate the average value of these two historical corrosion parameters, and perform the second operation based on the difference between the average value of these two historical corrosion parameters and the comprehensive corrosion parameter. The second operation includes jumping to the next set of historical corrosion parameters and setting these two historical corrosion parameters as the current corrosion parameters; When iterating through each group of historical corrosion parameters, and the second operation corresponding to each group of historical corrosion parameters is to jump to the next group of historical corrosion parameters, select any three historical corrosion parameters. The logic for repeatedly calculating the average and the logic for performing the second operation; Until any set of historical corrosion parameters exists, the corresponding second operation is to set these two historical corrosion parameters as the current corrosion parameters to obtain the corrosion parameters corresponding to the complex corrosion type of the subgraph. Based on the time sequence, the corrosion parameters of each subgraph are traversed and arranged in order to obtain the corrosion parameter sequence. The corrosion parameter sequence includes the radial depth sequence, the axial length sequence, and the circumferential width sequence.
[0013] In a preferred embodiment of the gas safety monitoring system described in this invention, the expression for calculating the radial depth is: ; ; in, Let z be the proportion of the stress in the z-direction in the sum of the stresses in all directions. It is a constant. This is the difference between the pipe wall thickness and the radial depth. It is the ratio of half the radial depth to the pipe radius. It is half the value of the depth. Where the pipe radius is; The radial depth is then expressed as Twice the value; Methods for calculating defect area include: ; in, For ultimate load, For standard load, Radial depth The defect area; The expression for calculating the axial length is as follows: ; in, , It is a constant. It is expressed as an exponential expression with base e. This is the exponential part of the exponential expression. This refers to the axial length. The expression for calculating the circumferential width is as follows: ; in, The circumferential width.
[0014] As a preferred embodiment of the gas safety monitoring system of the present invention, the method for the monitoring module to determine whether the target pipeline is under maintenance includes obtaining the maximum value in the corrosion parameter sequence of each type, and comparing the maximum value in the corrosion parameter sequence with the corresponding allowable threshold. If the maximum value in any type of corrosion parameter sequence is greater than the corresponding allowable threshold, a maintenance signal is sent. If the maximum value in all types of corrosion parameter sequences is less than or equal to the corresponding allowable threshold, then jump to the next pipeline and repeat the logic of each module.
[0015] The beneficial effects of this invention are as follows: By setting trigger conditions and a historical data tracing mechanism, it effectively identifies the pseudo-stationary state of single corrosion axial length and complex corrosion spacing under special circumstances, avoiding misjudging pipelines with actual corrosion as non-corrosive. The Von Mises yield criterion is used to calculate the remaining strength of the pipeline, fully considering the elastic-plastic characteristics of urban gas pipeline materials. Compared with the traditional elastic failure criterion, it is more in line with the actual failure mechanism of the pipeline. The continuous monitoring data is discretized into subgraphs, reducing the computational complexity of subsequent corrosion type matching. Through historical corrosion defect database matching and difference threshold control, the equivalent quantification of multiple corrosion interactions is achieved, solving the nonlinear problem of complex corrosion superposition, and realizing the mechanism, quantification, and prediction of gas pipeline safety supervision. Attached Figure Description
[0016] Figure 1 This is a basic flowchart of a gas safety monitoring system provided in one embodiment of the present invention. Detailed Implementation
[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0018] It should be understood that the step numbers used herein are for ease of description only and are not intended to limit the order in which the steps are performed. It should also be understood that the terminology used in this specification is for the purpose of describing specific embodiments only and is not intended to limit the invention.
[0019] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.
[0020] The terms “comprising” and “including” indicate the presence of the described feature, whole, step, operation, element and / or component, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.
[0021] The term “and / or” refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes these combinations.
[0022] Example, refer to Figure 1 As an embodiment of the present invention, a gas safety monitoring system is provided, including a calculation module, a matching module and a monitoring module; The calculation module calculates the remaining strength sequence of the pipeline based on the pipeline stress sequence; The remaining strength of the pipe was calculated using the Von Mises yield criterion formula. The matching module matches the corrosion type sequence and calculates the corrosion parameter sequence based on the pipeline's remaining strength sequence and pipeline parameters; Corrosion types include simple corrosion and complex corrosion; Corrosion parameters include axial length, circumferential width, and radial depth; The monitoring module determines whether the target pipeline needs maintenance based on the corrosion parameter sequence. If it does, it sends a maintenance signal; otherwise, it jumps to the next pipeline and repeats the logic of each module.
[0023] More preferably, this invention effectively identifies the pseudo-stationary state of single corrosion axial length and complex corrosion spacing under special circumstances by setting trigger conditions and historical data tracing mechanisms, avoiding misjudging pipelines with actual corrosion as non-corrosive. It uses the Von Mises yield criterion to calculate the remaining strength of the pipeline, fully considering the elastic-plastic characteristics of urban gas pipeline materials. Compared with the traditional elastic failure criterion, it is more in line with the actual failure mechanism of the pipeline. It discretizes continuous monitoring data into subgraphs, reducing the computational complexity of subsequent corrosion type matching. Through historical corrosion defect database matching and difference threshold control, it achieves the equivalent quantification of multiple corrosion interactions, solves the nonlinear problem of complex corrosion superposition, and realizes the mechanism, quantification, and prediction of gas pipeline safety supervision.
[0024] Pipeline stress sequence is a time series of stresses parallel to the coordinate axes obtained in a three-dimensional coordinate system constructed for the target pipeline. The pipeline stress sequence was acquired using stress sensors. More preferably, the stress sensor collects the pipeline stress at first intervals of a certain duration.
[0025] Pipeline stress includes x-direction stress, y-direction stress, and z-direction stress, and pipeline stress is expressed as the internal pressure of the pipeline.
[0026] More preferably, for the target pipe, the method for constructing the three-dimensional coordinate system includes: obtaining the target pipe, selecting the central axis of the target pipe, the central axis being represented as the central axis perpendicular to the cross-section, taking the midpoint of the central axis as the origin, taking the direction from the origin to any endpoint of the central axis as the positive x-axis, taking any direction parallel to the cross-section and perpendicular to the x-axis as the positive y-axis, and taking any direction perpendicular to the plane formed by x and y as the positive z-axis, and constructing the three-dimensional coordinate system.
[0027] The formula for calculating the residual strength of a pipeline is as follows: ; in, For the remaining strength of the pipe, For x-direction stress, For y-direction stress, The stress is in the z-direction.
[0028] More preferably, since the material of urban gas pipelines is usually elastic-plastic, it undergoes linear strengthening after reaching the yield limit and does not immediately break. Therefore, it is most appropriate to use the plastic failure criterion to determine whether the pipeline will fail. The equivalent stress of the pipeline is analyzed by the Von Mises yield criterion. When the maximum value of the equivalent stress reaches the ultimate tensile strength of the pipe, it is equivalent to pipeline failure. Therefore, the equivalent stress is regarded as the remaining strength of the pipeline.
[0029] For the pipeline remaining strength sequence, a trigger condition is configured. When the trigger condition is not met, the pipeline remaining strength sequence is sent to the matching module. When the trigger condition is met, a new pipeline remaining strength sequence is set, and the first operation is performed based on the new pipeline remaining strength sequence. The trigger condition is defined as the change in the pipeline's remaining strength sequence being less than or equal to the first value; The first operation includes jumping to the next pipe and sending the new pipe's remaining strength sequence to the matching module; More preferably, the calculation of the change is based on the same type of stress. For example, the difference between the maximum and minimum values of the x-direction stress, the difference between the maximum and minimum values of the y-direction stress, and the difference between the maximum and minimum values of the z-direction stress are calculated. When the change in any type of stress does not meet the triggering condition, the remaining strength sequence of the pipeline is sent to the matching module; When the changes in each type of stress meet the triggering conditions, a new pipeline residual strength sequence is set.
[0030] More preferably, the first value is 1.2 MPa.
[0031] The calculation logic for the change includes obtaining the maximum and minimum values in the pipeline's remaining strength sequence, calculating the difference between the maximum and minimum values, and setting this difference as the change. The setting logic for the new pipeline residual strength sequence includes obtaining the total monitoring time of this pipeline residual strength sequence, selecting half of the total monitoring time value, and recording it as the search time; Based on the search duration, starting from the initial time point of this set of pipeline remaining strength sequences, the historical pipeline remaining strength sequences of the target pipeline are obtained in reverse chronological order. Arrange the historical pipeline residual strength sequence and this set of pipeline residual strength sequences in chronological order to obtain a new pipeline residual strength sequence.
[0032] More preferably, by supplementing the data on the remaining strength of the pipeline monitored over a historical period with data on changes insufficient to constitute corrosion, it is easier to accurately obtain the value of the change in data and avoid omissions due to insufficient monitoring time of the pipeline's remaining strength.
[0033] More preferably, according to the prior art, there are special cases. In the first special case, the remaining strength of the pipeline, under single corrosion conditions, no longer changes when the axial length is greater than a second value, where the second value is expressed as... ,in, The outer diameter of the pipe. For pipe wall thickness; In the second special case, the remaining strength of the pipeline, under complex corrosion conditions, remains unchanged when the distance between the midpoints of adjacent axial lengths is greater than the third value. This third value is expressed as... ; This application takes into account these two special cases. If the target pipeline is in either of these two special cases during the total monitoring time of this set of pipeline residual strength sequences, the change in the target pipeline during the total monitoring time will be less than the first value, and it will be mistakenly judged as a non-corrosion state. Therefore, this application supplements this set of pipeline residual strength sequences based on the historical pipeline residual strength sequences of the target pipeline to determine the change in the target pipeline, thereby making it less likely to be misjudged.
[0034] More preferably, since this application is applied to long-term gas pipeline corrosion monitoring, the conventional cycle for gas pipeline corrosion monitoring is 6 months. The total monitoring time for this set of pipeline residual strength sequences is set to 6 months, which is a monitoring cycle that can basically cover the data characteristics. Therefore, tracing back 3 months of historical data is sufficient to obtain the data change characteristics.
[0035] Based on the calculation logic of the change, calculate the change corresponding to the new pipeline residual strength sequence; Determine whether the change in the new pipeline remaining strength sequence meets the triggering condition. If yes, set the first operation to jump to the next pipeline. If no, set the first operation to send the new pipeline remaining strength sequence to the matching module.
[0036] More preferably, the maximum and minimum values in the new pipeline residual strength sequence are selected, the difference between the maximum and minimum values is calculated, and this difference is recorded as the change in the new pipeline residual strength sequence.
[0037] More preferably, by ignoring the target pipes that meet the triggering conditions, that is, ignoring the target pipes with small stress changes within a monitoring period that sufficiently covers the data characteristics, and jumping to the next pipe, computational redundancy is reduced, thereby improving the overall computational efficiency and real-time response capability of the system.
[0038] More preferably, when the change in stress of each type meets the triggering condition, the process jumps to the next pipeline; When the change in any type of stress does not meet the triggering condition, a new sequence of remaining pipeline strength is sent to the matching module.
[0039] More preferably, when a new pipeline residual strength sequence is sent to the matching module, the data analyzed in the matching module, i.e., the pipeline residual strength sequence, is equivalent to the new pipeline residual strength sequence.
[0040] Pipe parameters include pipe wall thickness and pipe radius; The matching logic for the corrosion type sequence includes: based on the point plotting method, using a smooth curve, plotting a curve of the pipeline's remaining strength sequence, where smoothness means that it is continuous and differentiable at any point on the curve, the vertical axis of the curve represents the pipeline's remaining strength, and the horizontal axis represents the monitoring time point, which is distributed within the total monitoring time. Identify the inflection points of the curve; Based on the inflection points of the curve, the curve is divided into N sub-graphs; Based on the pipeline parameters of the target pipeline, retrieve the standard corrosion curve corresponding to the pipeline parameters. Based on the shape feature extraction algorithm of machine vision, extract the first feature of any sub-image and extract the second feature of any standard corrosion curve. Calculate the cosine similarity between the first and second feature using the cosine similarity formula. Based on the comparison between cosine similarity and a preset similarity threshold, the erosion type corresponding to the sub-image is determined.
[0041] More preferably, when the cosine similarity is greater than or equal to a preset similarity threshold, the corresponding standard erosion type is set as the erosion type of the sub-image; When the cosine similarity is less than the preset similarity threshold, jump to the next standard erosion curve and repeat the cosine similarity calculation process and the comparison process between the cosine similarity and the preset similarity threshold until the cosine similarity is greater than or equal to the preset similarity threshold. Then, set the corresponding standard erosion type as the erosion type of the sub-graph.
[0042] More preferably, when the data analyzed by the matching module is a new pipeline residual strength sequence, the total monitoring duration of the monitoring time point distribution is expressed as the sum of the original total monitoring duration and the monitoring duration of the traced historical pipeline residual strength sequence.
[0043] More preferably, the machine vision shape feature extraction algorithm includes the Harris corner detection algorithm, the Canny edge detection algorithm, and the curvature-based contour feature extraction algorithm. The use of machine vision shape feature extraction algorithms to extract the shape features of the image is an existing technology and will not be described in detail here.
[0044] More preferably, the preset similarity threshold is set to 0.8.
[0045] The logic for identifying inflection points in a curve includes obtaining the function expression of the curve using mathematical software, and then taking the second derivative of the function expression to obtain the second derivative function. Find the zero of the second derivative and determine whether the product of the second derivative values on both sides of the zero is negative; The expression for determining whether the signs of the second derivatives on both sides of the zero point change is: ; in, It is the product of the second derivative values on both sides of the zero point. It is a second derivative function. This represents the x-coordinate of the zero point in the function expression of the curve, i.e., the monitoring time point corresponding to the zero point. It is a constant; More preferably, The value is usually chosen as 1.2 × 10. -3 s.
[0046] If yes, then the x-coordinate corresponding to the zero point is determined as the x-coordinate of the inflection point; otherwise, the corresponding zero point is deleted. The subgraph segmentation logic includes selecting two inflection points that are adjacent in time sequence, selecting the median of the horizontal coordinates of these two inflection points, obtaining the point on the curve corresponding to the median, setting the point on the curve corresponding to the median as the cutting point, drawing a straight line parallel to the vertical axis through the cutting point, and setting the straight line as the cutting line. Iterate through the inflection points that are adjacent in time sequence for each group to obtain the cutting line corresponding to the inflection points that are adjacent in time sequence for each group. Based on this cutting line, the curve is divided into sub-graphs.
[0047] More preferably, when there is only one inflection point, the original curve is set as a sub-graph.
[0048] Calculate the corrosion parameter sequence based on the corrosion type sequence; The calculation logic for the corrosion parameter sequence includes: performing sequential calculations on the subgraphs according to the time order to obtain the corrosion parameter sequence corresponding to the subgraphs; When the corrosion type corresponding to the subgraph is single corrosion, the calculation logic of the corrosion parameters includes calculating the radial depth based on the pipe radius and the proportion of the z-direction stress in the sum of the stresses in each direction. More preferably, the proportion of z-direction stress in the sum of all-directional stresses is expressed as the ratio of z-direction stress to the sum of all-directional stresses, where z-direction stress is expressed as the average value of z-direction stress within the time period corresponding to the subgraph, and the sum of all-directional stresses is expressed as the average value of the sum of all-directional stresses within the time period corresponding to the subgraph, where the sum of all-directional stresses is expressed as the sum of the moduli of all-directional stresses.
[0049] Calculate the ratio of radial depth to pipe wall thickness, match the corresponding ultimate load based on the ratio of radial depth to pipe wall thickness, and obtain the standard load of the target pipe. More preferably, the ultimate load is obtained from a lookup table of ultimate loads (MPa) of the target pipeline under different defect parameters obtained from finite element analysis and comparison with ASME B31G. The corresponding ultimate load is obtained by inputting the ratio of radial depth to pipeline wall thickness into the lookup table. The ultimate load is expressed as the maximum average value of anisotropic stress that the pipeline can withstand.
[0050] More preferably, the standard load of the target pipeline is obtained based on the factory calibration data of the target pipeline.
[0051] Based on the ultimate load and standard load, the defect area is obtained, and based on the defect area and radial depth, the axial length is calculated. Calculate the circumferential width based on the pipe wall thickness, radial depth, and stress in all directions; When the corrosion type corresponding to the subgraph is complex corrosion, the calculation logic of the corrosion parameters includes calculating the corrosion parameters according to the calculation logic of the corrosion parameters when the corrosion type corresponding to the subgraph is single corrosion, and denoted as the comprehensive corrosion parameters. Obtain historical corrosion parameters corresponding to the target pipeline model. The historical corrosion parameters include historical axial length, historical radial depth, and historical circumferential width. More preferably, the method for obtaining historical corrosion parameters includes: identifying the target pipeline model, retrieving the historical corrosion defect database, inputting the target pipeline model into the historical corrosion defect database, and matching the historical corrosion type and historical corrosion parameters corresponding to the target pipeline model. Select the historical corrosion parameters corresponding to the historical corrosion type of complex corrosion, and calculate the corrosion parameters for the sub-graph when the corrosion type is complex corrosion based on the historical corrosion parameters corresponding to the historical corrosion type of complex corrosion.
[0052] Select any two historical corrosion parameters, calculate the average value of these two historical corrosion parameters, and perform the second operation based on the difference between the average value of these two historical corrosion parameters and the comprehensive corrosion parameter. The second operation includes jumping to the next set of historical corrosion parameters and setting these two historical corrosion parameters as the current corrosion parameters; More preferably, the third value is set as the difference threshold, wherein the third values corresponding to the axial length, circumferential width, and radial depth are different. In one implementation case, the third values corresponding to the axial length, circumferential width, and radial depth are selected as 1.5 mm, 0.8 mm, and 0.3 mm, respectively. Since the circumferential width has the greatest impact on pipe corrosion, the third value corresponding to the circumferential width is set to the minimum value, and the axial length has the least impact on pipe corrosion, so the third value corresponding to the circumferential width is set to the maximum value.
[0053] Select the absolute value of the difference between the average of these two historical corrosion parameters and the comprehensive corrosion parameter, and compare the absolute value of this difference with the third value. If the absolute value of the difference is less than or equal to the third value, then the second operation is set to set these two historical corrosion parameters as the current corrosion parameters; If the absolute value of the difference is greater than the third value, then the second operation is set to jump to the next set of historical corrosion parameters.
[0054] When iterating through each group of historical corrosion parameters, and the second operation corresponding to each group of historical corrosion parameters is to jump to the next group of historical corrosion parameters, select any three historical corrosion parameters. The logic for repeatedly calculating the average and the logic for performing the second operation; Until any set of historical corrosion parameters exists, the corresponding second operation is to set these two historical corrosion parameters as the current corrosion parameters to obtain the corrosion parameters corresponding to the complex corrosion type of the subgraph. Based on the time sequence, the corrosion parameters of each subgraph are traversed and arranged in order to obtain the corrosion parameter sequence. The corrosion parameter sequence includes the radial depth sequence, the axial length sequence, and the circumferential width sequence.
[0055] The expression for calculating radial depth is as follows: ; ; in, Let z be the proportion of the stress in the z-direction in the sum of the stresses in all directions. It is a constant. This is the difference between the pipe wall thickness and the radial depth. It is the ratio of half the radial depth to the pipe radius. It is half the value of the depth. Where the pipe radius is; The radial depth is then expressed as Twice the value; Methods for calculating defect area include: ; in, For ultimate load, For standard load, Radial depth The defect area; The expression for calculating the axial length is as follows: ; in, , It is a constant. It is expressed as an exponential expression with base e. This is the exponential part of the exponential expression. This refers to the axial length. The expression for calculating the circumferential width is as follows: ; in, The circumferential width.
[0056] The method for the monitoring module to determine whether the target pipeline is under maintenance includes obtaining the maximum value in the corrosion parameter sequence for each type, and comparing the maximum value in the corrosion parameter sequence with the corresponding allowable threshold. If the maximum value in any type of corrosion parameter sequence is greater than the corresponding allowable threshold, a maintenance signal is sent. If the maximum value in the sequence of all types of corrosion parameters is less than or equal to the corresponding allowable threshold, then jump to the next pipeline and repeat the logic of each module. The maintenance signal includes the target pipe label number and corrosion parameter sequence. The target pipe location and stress sensor location are automatically indexed by the target pipe label number.
[0057] More preferably, this invention effectively identifies the pseudo-stationary state of single corrosion axial length and complex corrosion spacing under special circumstances by setting trigger conditions and historical data tracing mechanisms, avoiding misjudging pipelines with actual corrosion as non-corrosive. It uses the Von Mises yield criterion to calculate the remaining strength of the pipeline, fully considering the elastic-plastic characteristics of urban gas pipeline materials. Compared with the traditional elastic failure criterion, it is more in line with the actual failure mechanism of the pipeline. It discretizes continuous monitoring data into subgraphs, reducing the computational complexity of subsequent corrosion type matching. Through historical corrosion defect database matching and difference threshold control, it achieves the equivalent quantification of multiple corrosion interactions, solves the nonlinear problem of complex corrosion superposition, and realizes the mechanism, quantification, and prediction of gas pipeline safety supervision.
[0058] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code. The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0059] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the protection scope of the present invention.
Claims
1. A gas safety monitoring system, characterized in that, It includes a calculation module, a matching module, and a monitoring module; The calculation module calculates the remaining strength sequence of the pipeline based on the pipeline stress sequence; The remaining strength of the pipe was calculated using the Von Mises yield criterion formula. The matching module matches the corrosion type sequence and calculates the corrosion parameter sequence based on the pipeline's remaining strength sequence and pipeline parameters; Corrosion types include simple corrosion and complex corrosion; Corrosion parameters include axial length, circumferential width, and radial depth; The monitoring module determines whether the target pipeline needs maintenance based on the corrosion parameter sequence. If it does, it sends a maintenance signal; otherwise, it jumps to the next pipeline and repeats the logic of each module.
2. The gas safety monitoring system as described in claim 1, characterized in that, Pipeline stress sequence is a time series of stresses parallel to the coordinate axes obtained in a three-dimensional coordinate system constructed for the target pipeline. The pipeline stress sequence was acquired using stress sensors. Pipeline stress includes x-direction stress, y-direction stress, and z-direction stress, and pipeline stress is expressed as the internal pressure of the pipeline.
3. The gas safety monitoring system as described in claim 1, characterized in that, The formula for calculating the residual strength of a pipeline is as follows: ; in, For the remaining strength of the pipe, For x-direction stress, For y-direction stress, The stress is in the z-direction.
4. The gas safety monitoring system as described in claim 3, characterized in that, For the pipeline remaining strength sequence, a trigger condition is configured. When the trigger condition is not met, the pipeline remaining strength sequence is sent to the matching module. When the trigger condition is met, a new pipeline remaining strength sequence is set, and the first operation is performed based on the new pipeline remaining strength sequence. The trigger condition is defined as the change in the pipeline's remaining strength sequence being less than or equal to the first value; The first operation includes jumping to the next pipe and sending the new pipe's remaining strength sequence to the matching module; The calculation logic for the change includes obtaining the maximum and minimum values in the pipeline's remaining strength sequence, calculating the difference between the maximum and minimum values, and setting this difference as the change. The setting logic for the new pipeline residual strength sequence includes obtaining the total monitoring time of this pipeline residual strength sequence, selecting half of the total monitoring time value, and recording it as the search time; Based on the search duration, starting from the initial time point of this set of pipeline remaining strength sequences, the historical pipeline remaining strength sequences of the target pipeline are obtained in reverse chronological order. Arrange the historical pipeline residual strength sequence and this set of pipeline residual strength sequences in chronological order to obtain a new pipeline residual strength sequence.
5. The gas safety monitoring system as described in claim 4, characterized in that, The first operation's setup logic includes a calculation logic based on the change amount, which calculates the change amount corresponding to the new pipeline residual strength sequence. Determine whether the change in the new pipeline remaining strength sequence meets the triggering condition. If yes, set the first operation to jump to the next pipeline. If no, set the first operation to send the new pipeline remaining strength sequence to the matching module.
6. The gas safety monitoring system as described in claim 1, characterized in that, Pipe parameters include pipe wall thickness and pipe radius; The matching logic for corrosion type sequences includes: using a point-plotting method, drawing a curve of the pipeline's remaining strength sequence with a smooth curve; Identify the inflection points of the curve; Based on the inflection points of the curve, the curve is divided into N sub-graphs; Based on the pipeline parameters of the target pipeline, retrieve the standard corrosion curve corresponding to the pipeline parameters. Based on the shape feature extraction algorithm of machine vision, extract the first feature of any sub-image and extract the second feature of any standard corrosion curve. Calculate the cosine similarity between the first and second feature using the cosine similarity formula. Based on the comparison between cosine similarity and a preset similarity threshold, the erosion type corresponding to the sub-image is determined.
7. The gas safety monitoring system as described in claim 1, characterized in that, The logic for identifying inflection points in a curve includes obtaining the function expression of the curve using mathematical software, and then taking the second derivative of the function expression to obtain the second derivative function. Find the zero of the second derivative and determine whether the product of the second derivative values on both sides of the zero is negative; If yes, then the x-coordinate corresponding to the zero point is determined as the x-coordinate of the inflection point; otherwise, the corresponding zero point is deleted. The subgraph segmentation logic includes selecting two inflection points that are adjacent in time sequence, selecting the median of the horizontal coordinates of these two inflection points, obtaining the point on the curve corresponding to the median, setting the point on the curve corresponding to the median as the cutting point, and drawing a cutting line parallel to the vertical axis through the cutting point. The curve is divided into sub-graphs based on the cutting lines.
8. The gas safety monitoring system as described in claim 1, characterized in that, The calculation logic for the corrosion parameter sequence includes: performing sequential calculations on the subgraphs according to the time order to obtain the corrosion parameter sequence corresponding to the subgraphs; When the corrosion type corresponding to the subgraph is single corrosion, the calculation logic of the corrosion parameters includes calculating the radial depth based on the pipe radius and the proportion of the z-direction stress in the sum of the stresses in each direction. Calculate the ratio of radial depth to pipe wall thickness, match the corresponding ultimate load based on the ratio of radial depth to pipe wall thickness, and obtain the standard load of the target pipe. Based on the ultimate load and standard load, the defect area is obtained, and based on the defect area and radial depth, the axial length is calculated. Calculate the circumferential width based on the pipe wall thickness, radial depth, and stress in all directions; When the corrosion type corresponding to the subgraph is complex corrosion, the calculation logic of the corrosion parameters includes calculating the corrosion parameters according to the calculation logic of the corrosion parameters when the corrosion type corresponding to the subgraph is single corrosion, and denoted as the comprehensive corrosion parameters. Obtain historical corrosion parameters corresponding to the target pipeline model. The historical corrosion parameters include historical axial length, historical radial depth, and historical circumferential width. Select any two historical corrosion parameters, calculate the average value of these two historical corrosion parameters, and perform the second operation based on the difference between the average value of these two historical corrosion parameters and the comprehensive corrosion parameter. The second operation includes jumping to the next set of historical corrosion parameters and setting these two historical corrosion parameters as the current corrosion parameters; When iterating through each group of historical corrosion parameters, and the second operation corresponding to each group of historical corrosion parameters is to jump to the next group of historical corrosion parameters, select any three historical corrosion parameters. The logic for repeatedly calculating the average and the logic for performing the second operation; Until any set of historical corrosion parameters exists, the corresponding second operation is to set these two historical corrosion parameters as the current corrosion parameters to obtain the corrosion parameters corresponding to the complex corrosion type of the subgraph. Based on the time sequence, the corrosion parameters of each subgraph are traversed and arranged in order to obtain the corrosion parameter sequence. The corrosion parameter sequence includes the radial depth sequence, the axial length sequence, and the circumferential width sequence.
9. The gas safety monitoring system as described in claim 8, characterized in that, The expression for calculating radial depth is as follows: ; ； in, Let z be the proportion of the stress in the z-direction in the sum of the stresses in all directions. It is a constant. This is the difference between the pipe wall thickness and the radial depth. It is the ratio of half the radial depth to the pipe radius. It is half the value of the depth. Where the pipe radius is; The radial depth is then expressed as Twice the value; Methods for calculating defect area include: ; in, For ultimate load, For standard load, Radial depth The defect area; The expression for calculating the axial length is as follows: ; in, , It is a constant. It is expressed as an exponential expression with base e. This is the exponential part of the exponential expression. This refers to the axial length. The expression for calculating the circumferential width is as follows: ; in, The circumferential width.
10. The gas safety monitoring system as described in claim 1, characterized in that, The method for the monitoring module to determine whether the target pipeline is under maintenance includes obtaining the maximum value in the corrosion parameter sequence for each type, and comparing the maximum value in the corrosion parameter sequence with the corresponding allowable threshold. If the maximum value in any type of corrosion parameter sequence is greater than the corresponding allowable threshold, a maintenance signal is sent. If the maximum value in all types of corrosion parameter sequences is less than or equal to the corresponding allowable threshold, then jump to the next pipeline and repeat the logic of each module.