Intelligent pipeline corrosion monitoring and protection system

Abstract

The invention relates to the technical field of corrosion monitoring, in particular to an intelligent pipeline corrosion monitoring and protection system which comprises a dynamic potential disturbance measurement module, a local microcell scanning module, a corrosion rate calculation module, a corrosion risk distribution analysis module and an environmental parameter compensation module. According to the invention, accurate measurement is realized, the spatial resolution is improved, and the current response change rate is calculated by measuring the reference potential of the surface of the pipeline, applying instantaneous disturbance, combining current change differential operation, dynamically tracking the corrosion process, improving the real-time response capability and arranging a microelectrode array to cover corrosion hot spots; the corrosion current density is solved by combining the electrochemical characteristics of the material, the corrosion rate is dynamically predicted, regional distribution is analyzed based on the change of the corrosion rate, the corrosion risk assessment precision is optimized, environmental factors are monitored, disturbance parameters are adjusted, interference is compensated, the monitoring accuracy under different working conditions is ensured, and data stability and protection measure optimization are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of corrosion monitoring, and particularly to an intelligent pipeline corrosion monitoring and protection system. Background Art

[0002] The technical field of corrosion monitoring involves detecting, analyzing, and evaluating the corrosion behavior of metals and their alloys under various environmental conditions. This technical field mainly involves corrosion detection methods, corrosion data collection and analysis, corrosion protection measures, etc. Corrosion monitoring usually includes methods such as corrosion rate detection based on electrochemical measurements, wall thickness measurement based on ultrasonic waves, and material integrity assessment based on ray or electromagnetic technologies, and combines long-term monitoring data to analyze the degradation trend of materials under the influence of different environmental factors. This technical field is widely used in industries such as petroleum, natural gas, chemical industry, shipbuilding, and ocean engineering. By real-time monitoring the corrosion status of key structures such as pipelines and equipment, it provides data support for taking corresponding protection measures.

[0003] Among them, an intelligent pipeline corrosion monitoring and protection system refers to using a variety of sensing means to real-time monitor the corrosion state of the pipeline, and taking corresponding protection measures based on the analysis results of the data. This system usually includes an electrochemical corrosion sensor for measuring parameters such as the potential and current density of the inner and outer walls of the pipeline, continuously monitoring the wall thickness through an ultrasonic thickness gauge sensor, and uploading the detection data to the monitoring terminal through wireless data transmission technology. In addition, the system uses machine learning algorithms to analyze the collected data, predicts the corrosion development trend through historical data modeling and pattern recognition, and automatically adjusts the cathodic protection system or intelligent coating to release preservatives based on the analysis results to slow down the corrosion process.

[0004] The existing technologies rely on electrochemical sensors, ultrasonic thickness measurement, and ray or electromagnetic detection, but it is difficult to provide corrosion data with high spatio-temporal resolution. Point-type electrochemical sensors are difficult to accurately characterize the dynamic changes of corrosion hotspots, resulting in blind spots in local corrosion assessment. Although ultrasonic thickness measurement can monitor the change of the wall thickness, it cannot directly reflect the corrosion rate, affecting the accuracy of trend prediction. Ray and electromagnetic methods rely on regular detection and are difficult to achieve continuous monitoring, resulting in being discovered only after the corrosion has intensified, increasing the maintenance risk. The existing monitoring methods do not consider enough the influence of environmental factors, usually corrected through long-term trend analysis, and are difficult to cope with real-time measurement errors under complex working conditions, affecting the reliability of the data, resulting in a lag in the adjustment of protection measures and reducing the effectiveness of corrosion control. Summary of the Invention

[0005] The purpose of the present invention is to solve the drawbacks existing in the prior art, and to propose an intelligent pipeline corrosion monitoring and protection system.

[0006] To achieve the above object, the present invention adopts the following technical solutions: An intelligent pipeline corrosion monitoring and protection system includes:

[0007] The dynamic potential perturbation measurement module obtains the reference potential on the pipeline surface, controls the potential source to apply an instantaneous perturbation, adjusts the perturbation amplitude and records the current changes before and after the perturbation, and obtains the transient current change amount through differential operation;

[0008] The local micro-region scanning module, based on the transient current change amount, arranges a microelectrode array, adjusts the positions of the microelectrodes to cover hot spots, records the local current response, calculates the distribution gradient, and obtains the local corrosion rate distribution value;

[0009] The corrosion rate calculation module calculates the change rate of the current response amplitude according to the transient current change amount and the local corrosion rate distribution value, combines the electrochemical characteristics of the pipeline material to obtain the corrosion current density, calculates the dynamic change of the corrosion rate, calculates the time series according to the change amount, adjusts the measurement rate increment, and obtains the dynamic change value of the corrosion rate;

[0010] The corrosion risk distribution analysis module calculates the corrosion rate change within the region according to the dynamic change value of the corrosion rate, analyzes the regions where the local ratio exceeds the standard, adjusts the scanning step size, calculates the hot spot range gradient, and obtains the corrosion hot spot distribution parameters;

[0011] The environmental parameter compensation module calls the corrosion hot spot distribution parameters, monitors the temperature, pressure, and flow rate of the pipeline operating environment, calculates the environmental impact, adjusts the perturbation amplitude and interval, and calculates and obtains the environmental parameter compensation correction value.

[0012] As a further solution of the present invention, the transient current change amount includes the perturbation amplitude, the current before the perturbation, and the current after the perturbation. The local corrosion rate distribution value is specifically the local current response and the distribution gradient. The dynamic change value of the corrosion rate includes the change rate of the current response amplitude, the corrosion current density, the dynamic change of the corrosion rate, and the measurement rate increment. The corrosion hot spot distribution parameters specifically refer to the corrosion rate change within the region, the regions where the local ratio exceeds the standard, the scanning step size, and the hot spot range gradient.

[0013] As a further solution of the present invention, the dynamic potential perturbation measurement module includes:

[0014] The reference potential acquisition sub-module obtains the potential on the pipeline surface, calls the external reference electrode of the pipeline to detect the reference potential, screens the potential data at different differential time points, calculates the potential fluctuation range, and selects the measurement value in the potential stable interval as the reference potential on the pipeline surface;

[0015] The perturbation potential application sub-module controls the potential source to output an instantaneous potential perturbation with a target amplitude based on the reference potential on the pipeline surface, adjusts the perturbation amplitude, records the current change on the pipeline surface after the perturbation, screens the perturbation data with stable current fluctuation values, and obtains the current change amount before and after the perturbation.

[0016] The transient current calculation sub-module, based on the current change amount before and after the perturbation, uses the formula:

[0017] ;

[0018] Obtain the transient current change trends in multiple time periods, calculate and establish the transient current change amount.

[0019] Where, represents the transient current change amount, represents the current value at the th moment after the perturbation, represents the current value at the th moment before the perturbation, represents the number of time segments, represents the applied perturbation potential, represents the reference potential on the pipeline surface, represents the equivalent resistance on the pipeline surface.

[0020] As a further solution of the present invention, the local micro-region scanning module includes:

[0021] The microelectrode layout sub-module, based on the transient current change amount, layouts a microelectrode array, detects the distribution of the transient current change amount, determines the regions with larger current change amounts, adjusts the microelectrode positions to cover the hot spots, and generates the hot spot coverage layout state.

[0022] The current response recording sub-module calls the hot spot coverage layout state, records the local current response, obtains the transient current data at multiple microelectrode positions, calculates the current response gradient distribution, and generates the current gradient distribution value.

[0023] The local corrosion rate calculation sub-module, based on the current gradient distribution value, calculates the distribution gradient, obtains the microelectrode spacing, the transient current change amount, and the current gradient distribution value, performs gradient calculation and weighted summation, using the formula:

[0024] ;

[0025] Obtain the local corrosion rate distribution value.

[0026] Where, represents the local corrosion rate distribution value, represents the current change amount at the th microelectrode position, represents the The distance between adjacent microelectrodes, is the number of microelectrodes.

[0027] As a further aspect of the present invention, the corrosion rate calculation module includes:

[0028] The current change analysis sub-module collects current response data on the pipeline surface based on the transient current change amount and the local corrosion rate distribution value, calculates the amplitude change rate of the current response per unit time, analyzes the change trend of the current response over time, and obtains the amplitude change rate of the current response;

[0029] The corrosion current density calculation sub-module calls the amplitude change rate of the current response, combines the electrochemical characteristics of the pipeline material, calculates the charge transfer relationship in the local area during the corrosion process, and uses the formula:

[0030] ;

[0031] Performs operations to obtain the current density per unit area during the corrosion process, and obtains the corrosion current density;

[0032] Wherein, represents the corrosion current density, represents the change amount of the current response per unit time, represents the measurement area, represents the charge transfer coefficient, represents the measurement time;

[0033] The corrosion rate trend calculation sub-module calls the corrosion current density, combines the polarization curve parameters of the material, calculates the dynamic change trend of the corrosion rate per unit time, adjusts the measurement rate increment, and obtains the dynamic change value of the corrosion rate.

[0034] As a further aspect of the present invention, the corrosion risk distribution analysis module includes:

[0035] The corrosion rate distribution calculation sub-module obtains the corrosion rate data at multiple positions within the region based on the dynamic change value of the corrosion rate, calculates the corrosion rate change rate between adjacent positions, constructs a distribution matrix of the corrosion rate change within multiple regions, calculates the corrosion rate gradient at multiple points, and generates a corrosion rate gradient matrix;

[0036] The ratio exceeding area identification sub-module calls the corrosion rate gradient matrix, calculates the local ratio of the corrosion rate change rate within multiple regions, sets a threshold, screens the regions where the ratio exceeds the standard, and calculates the distribution characteristics to obtain the distribution parameters of the exceeding area;

[0037] The hotspot range gradient calculation sub-module calls the over-standard area distribution parameters, adjusts the scanning step size, compares the corrosion rate change gradient of the local area, and uses the formula:

[0038] ;

[0039] Perform operations to obtain the corrosion hotspot distribution parameters;

[0040] Among them, represents the corrosion hotspot distribution parameter, represents the th corrosion rate gradient value at the th position, represents the scanning step size at the th position, represents the over-standard ratio of the th area, represents the neighborhood corrosion rate gradient difference degree of the th area,

[0041] As a further solution of the present invention, the environmental parameter compensation module includes:

[0042] The corrosion hotspot distribution calculation sub-module calls the corrosion hotspot distribution parameters, analyzes the corrosion intensity change trend of the differential area, obtains the corrosion hotspot distribution data, calculates the pipeline wall thickness change rate according to the distribution data, screens the corrosion intensification area, and calculates the corrosion growth rate data;

[0043] The operating environment monitoring sub-module monitors the temperature, pressure and flow rate of the pipeline operating environment based on the corrosion growth rate data, collects the operating parameters in the corresponding time period, and at the same time compares the change range of the operating parameters, calculates the temperature-flow rate synergistic influence factor, and uses the formula:

[0044] ;

[0045] Perform operations to obtain the temperature-flow rate synergistic influence factor data and obtain the environmental influence coefficient;

[0046] Among them, represents the temperature-flow rate synergistic influence factor, , are the maximum and minimum operating temperatures respectively, , are the maximum and minimum operating flow rates respectively, is the average pressure within the time period, is the corrosion influence coefficient set corresponding to the corrosion growth rate data, is the number of selected corrosion hotspot areas;

[0047] The perturbation amplitude adjustment sub-module calls the environmental impact coefficient, analyzes the perturbation influence range, calculates the perturbation correction value according to the environmental impact coefficient, adjusts the perturbation amplitude, determines the perturbation adjustment interval, and calculates and obtains the environmental parameter compensation correction value.

[0048] As a further solution of the present invention, the intelligent pipeline corrosion monitoring and protection system further includes a corrosion protection control module;

[0049] The corrosion protection control module intelligently adjusts the cathodic protection current or sacrificial anode configuration according to the corrosion hot spot distribution parameters and the dynamic change value of the corrosion rate, optimizes the corrosion protection measures, and dynamically adjusts the protection strategy to reduce the corrosion risk.

[0050] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0051] In the present invention, by measuring the reference potential on the pipeline surface and applying an instantaneous perturbation, and performing differential operation in combination with the current change before and after the perturbation, the corrosion process can be dynamically tracked, the transient current change amount can be obtained, and the real-time response ability of the corrosion state can be improved. By arranging a microelectrode array and adjusting the position to cover the hot spots, accurate measurement of local corrosion can be achieved, the spatial resolution can be improved, and the identification of corrosion hot spots can be more accurate. Calculate the change rate of the current response amplitude, and combine the electrochemical characteristics of the material to obtain the corrosion current density, and dynamically calculate the corrosion rate to ensure accurate prediction of the corrosion trend. Based on the dynamic change of the corrosion rate, calculate the regional corrosion rate distribution, analyze the area where the local ratio exceeds the standard, and adjust the scanning step size to optimize the accuracy of corrosion risk assessment. Monitor the temperature, pressure, and flow rate, calculate the environmental impact factors, adjust the perturbation amplitude and interval, compensate for environmental interference, ensure the monitoring accuracy under different working conditions, and ensure the stability of the data and timely adjustment of the protection measures. Brief Description of the Drawings

[0052] Figure 1 is the system flow chart of the present invention;

[0053] Figure 2 is the flow chart of the dynamic potential perturbation measurement module of the present invention;

[0054] Figure 3 is the flow chart of the local micro-region scanning module of the present invention;

[0055] Figure 4 is the flow chart of the corrosion rate calculation module of the present invention;

[0056] Figure 5 is the flow chart of the corrosion risk distribution analysis module of the present invention;

[0057] Figure 6 is the flow chart of the environmental parameter compensation module of the present invention. Detailed Embodiments

[0058] To make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0059] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention. In addition, in the description of the present invention, the meaning of "a plurality of" is two or more unless otherwise specifically defined.

[0060] Example 1, please refer to Figure 1 , an intelligent pipeline corrosion monitoring and protection system includes: a dynamic potential perturbation determination module that acquires the reference potential on the pipeline surface, controls the potential source to apply an instantaneous perturbation, adjusts the perturbation amplitude and records the current change before and after the perturbation, and performs differential operation to obtain the transient current change amount;

[0061] A local micro-region scanning module, based on the transient current change amount, arranges a microelectrode array, adjusts the positions of the microelectrodes to cover the hot spots, records the local current response, calculates the distribution gradient, and obtains the local corrosion rate distribution value;

[0062] A corrosion rate calculation module calculates the rate of change of the current response amplitude according to the transient current change amount and the local corrosion rate distribution value, combines the electrochemical characteristics of the pipeline material to obtain the corrosion current density, calculates the dynamic change of the corrosion rate, calculates the time series according to the change amount, adjusts the measurement rate increment, and obtains the dynamic change value of the corrosion rate;

[0063] A corrosion risk distribution analysis module calculates the change of the corrosion rate in the region according to the dynamic change value of the corrosion rate, analyzes the region where the local ratio exceeds the standard, adjusts the scanning step size, calculates the gradient of the hot spot range, and obtains the corrosion hot spot distribution parameters;

[0064] An environmental parameter compensation module calls the corrosion hot spot distribution parameters, monitors the temperature, pressure and flow rate of the pipeline operating environment, calculates the environmental impact, adjusts the perturbation amplitude and interval, and calculates and obtains the environmental parameter compensation correction value;

[0065] A corrosion protection control module intelligently adjusts the cathodic protection current or sacrificial anode configuration according to the corrosion hot spot distribution parameters and the dynamic change value of the corrosion rate, optimizes the corrosion protection measures, and dynamically adjusts the protection strategy to reduce the corrosion risk.

[0066] In the corrosion protection control module, it is first necessary to collect corrosion data on the surface of pipelines or metal structures, specifically including the distribution parameters of corrosion hotspots and the dynamic change values of corrosion rates. The data can be collected through electrochemical sensors, which can be installed on the inner or outer walls of the pipeline and measure the corrosion rate based on the change in electrode potential. For example, the corrosion rate detected in a certain pipeline section is 0.05 mm / year, while that in another section is 0.15 mm / year. The detected data is transmitted to the central data processing unit through wireless communication or wired connection. The data processing unit compares this corrosion rate information with historical corrosion data, filters out the areas where the corrosion rate changes significantly (such as exceeding 30%), and marks them as potential corrosion hotspots. These data are then used to calculate the adjustment amount of the cathodic protection current or the supplementary demand for sacrificial anodes. Specifically, when the corrosion rate in a certain area is detected to increase by more than 40% compared to the reference rate (such as 0.1 mm / year), the cathodic protection current in this area needs to be increased. The calculation of the current increase is based on Faraday's law, by calculating the required charge quantity and converting it into the current output quantity. For example, if the new corrosion current density in a certain area is 50 μA / cm², and calculated according to the area of 200 cm² in this area, the total current required is 10 mA. Then, the constant current source output of the cathodic protection system is adjusted to provide an additional 10 mA of protection current. At the same time, for the sacrificial anode system, when the total current demand of the corrosion hotspots in a certain area exceeds the design capacity (such as the preset maximum protection current of 20 mA), the anode material needs to be increased. When calculating the supplementary quantity, the anode consumption rate needs to be considered. For example, the current efficiency of a certain magnesium alloy sacrificial anode is 55%, then the actual current that can be provided is 11 mA / g, and the anode mass that needs to be increased after calculation can reach more than 1 g. The adjusted protection plan is continuously monitored with the change of environmental conditions and iteratively optimized through intelligent algorithms to ensure the dynamic adaptability of the cathodic protection current or anode configuration and ultimately reduce the corrosion risk.

[0067] The transient current change amount includes the disturbance amplitude, the current before disturbance, and the current after disturbance. The local corrosion rate distribution value is specifically the local current response and the distribution gradient. The dynamic change value of the corrosion rate includes the change rate of the current response amplitude, the corrosion current density, the dynamic change of the corrosion rate, and the measurement rate increment. The corrosion hotspot distribution parameter specifically refers to the change of the regional corrosion rate, the area where the local ratio exceeds the standard, the scanning step size, and the hotspot range gradient. The environmental parameter compensation and correction value includes the pipeline operation environment temperature, pressure, flow rate, environmental impact, disturbance amplitude, and disturbance interval.

[0068] Please refer to Figure 2 , the dynamic potential disturbance measurement module includes:

[0069] The reference potential acquisition sub-module acquires the surface potential of the pipeline, calls the external reference electrode of the pipeline to detect the reference potential, screens the potential data at different time points, calculates the potential fluctuation range, and selects the measured value in the potential stable interval as the surface reference potential of the pipeline;

[0070] First, by connecting the external reference electrode to the pipeline surface, the potential values at multiple time points are detected and these data are recorded to form a set of potential data sets that change with time. For example, when sampling once per second, 60 potential values can be obtained within one minute, and the data records are shown in Table 1 below:

[0071] Table 1 Pipeline surface potential data (unit: V)

[0072]

[0073] As shown in Table 1, there are slight fluctuations in the initially collected potential data. Next, different time points need to be screened, that is, the potential change amount between adjacent data points is calculated , if this change amount exceeds a preset threshold (such as 0.02 V), the measured value at this time point is excluded, otherwise it enters the next screening. Assume that at certain time points The calculation is as follows:

[0074] (reserved);

[0075] (excluded);

[0076] (reserved);

[0077] Finally, after excluding the abnormal data, the potential fluctuation range is calculated, using the difference between the maximum value and the minimum value. For example, The fluctuation range of the interval is calculated as , then, by setting a fluctuation threshold, such as 0.02 V, the stable potential interval that meets this condition is screened out. Finally, the mean value of the potential data within this interval is selected as the surface reference potential of the pipeline. For example, the mean value is calculated for 10 data points in the stable interval (-0.86 V to -0.85 V):

[0078] ;

[0079] Finally, the surface reference potential of the pipeline is obtained , this result shows that the surface potential of the pipeline remains at about -0.855 V within the stable interval, with a small fluctuation range, which can be used as a reference potential when applying the perturbation potential subsequently to ensure the stability of the reference potential during the measurement process and improve the accuracy of subsequent calculations.

[0080] The perturbation potential application sub-module controls the potential source to output an instantaneous potential perturbation with a target amplitude based on the reference potential on the pipeline surface, adjusts the perturbation amplitude, records the current change on the pipeline surface after the perturbation, screens the perturbation data with stable current fluctuation values, and obtains the current change amount before and after the perturbation.

[0081] First, based on the reference potential calculated in the previous paragraph , apply a perturbation potential . Set the perturbation amplitude to 0.1V, then the target perturbation potential is:

[0082] ;

[0083] The potential source instantaneously applies this potential and records the current change on the pipeline surface, recording once every 5ms. For example, the current change data before and after the perturbation is shown in Table 2 below:

[0084] Table 2 Current change data before and after the perturbation (unit: mA)

[0085]

[0086] Compare the currents before and after the perturbation and calculate the average change amount:

[0087] ;

[0088] Finally, obtain the current change amount before and after the perturbation . This result shows that after applying the perturbation potential, the current change on the pipeline surface is relatively stable and can be used for calculating the transient current characteristics and further analyzing the pipeline potential-current response characteristics in the follow-up.

[0089] The transient current calculation sub-module, based on the current change amount before and after the perturbation, uses the formula:

[0090] ;

[0091] Obtain the transient current change trends for multiple time periods, calculate and establish the transient current change amount;

[0092] Among them, represents the transient current change amount, represents the current value at the th moment after the perturbation, represents the current value at the th moment before the perturbation, represents the number of time segments, represents the applied perturbation potential, represents the reference potential on the pipeline surface, represents the equivalent resistance on the pipeline surface.

[0093] Calculate the transient current change amount using the formula :

[0094] ;

[0095] Set the number of time segments , and calculate according to Table 2 :

[0096] ;

[0097] Calculate the average value:

[0098] ;

[0099] Assume the equivalent resistance on the pipeline surface , then calculate the potential difference:

[0100] ;

[0101] Finally, calculate the change in transient current:

[0102] ;

[0103] This result shows that the change in transient current is 2 mA, which is related to the amplitude of the reference potential perturbation and the current response characteristics. Subsequently, it can be used to evaluate the pipeline corrosion state, electrode polarization behavior, and potential response trend to ensure the stability of the pipeline corrosion detection system under different perturbation conditions.

[0104] Please refer to Figure 3 , the local micro-region scanning module includes:

[0105] The microelectrode layout sub-module arranges a microelectrode array based on the change in transient current, detects the distribution of the change in transient current, determines the area with a large change in current, adjusts the microelectrode position to cover the hot spot, and generates the layout state of the hot spot coverage;

[0106] First, extract the transient current data at different positions, compare the current changes at multiple time points, and calculate the transient current increment at each microelectrode position. Among them, for the current change between time points and , the calculation can be , by setting the detection period , obtain the change trend of each microelectrode at multiple time points. Subsequently, the Sorting is performed to screen out the microelectrode positions whose changes are higher than the set threshold. The threshold can be set according to historical experimental data or the average current fluctuation rate. For example, the threshold is set to 1.5 times the mean of the total sample change to ensure that the selected area is the current hotspot. After the hotspot area is selected, the distribution of microelectrodes is adjusted, and an encrypted layout is adopted, that is, the density of microelectrodes is increased around the hotspot area to reduce the distance between adjacent microelectrodes to improve the spatial resolution of data acquisition. Assuming that the initial microelectrode distance is When the change in the hot spot area exceeds the set value, the microelectrode spacing in the area is reduced to , and redistribute the microelectrode array. After adjusting the layout state, a layout plan for microelectrode hotspot coverage is formed based on the optimized layout state, so as to ensure the effective coverage rate of the microelectrodes and obtain the final hotspot coverage layout state.

[0107] Table 3: Transient current changes at different microelectrode positions

[0108]

[0109] As shown in Table 3, the transient current changes at the microelectrode positions (2.0, 0.5) and (2.5, 0.5) are the highest, so it is necessary to increase the microelectrode density at these positions, reduce the spacing to 0.5 mm, and rearrange the microelectrode array to improve the detection accuracy and obtain the final hotspot coverage layout state.

[0110] The current response recording submodule calls the hotspot coverage layout state, records the local current response, obtains the transient current data at the multi-microelectrode positions, calculates the current response gradient distribution, and generates the current gradient distribution value;

[0111] Based on the optimized microelectrode array, the transient current changes at each microelectrode position are continuously recorded. Get the current value of all microelectrodes , and calculate the current difference between adjacent time points, that is, At the same time, in order to quantify the local current gradient change, the current data at adjacent microelectrode positions are gradient calculated, that is, ,in and is the microelectrode spacing. For example, if the spacing of the hot spot area in the aforementioned layout plan is set to 0.5 mm, this spacing is used for gradient calculation. Subsequently, the current gradient threshold is set for the calculated current gradient value. For example, when the gradient value is greater than 1.8 times the set mean, the area is marked as an area of ​​drastic current change, and the microelectrode current data of the area is extracted for subsequent calculations. This ensures the accuracy of the current data acquisition in the hot spot area and ultimately generates the current gradient distribution value.

[0112] Table 4: Transient current data at the microelectrode positions

[0113]

[0114] As shown in Table 4, the current gradient at the microelectrode position (2.5, 0.5) is the highest, which is 5.5 μA / mm. This area is marked as the area of drastic change. When calculating the local corrosion rate subsequently, the weight of this area will be increased to ensure the calculation accuracy.

[0115] The local corrosion rate calculation sub-module calculates the distribution gradient based on the current gradient distribution value, obtains the microelectrode spacing, the change amount of transient current, and the current gradient distribution value, performs gradient calculation and weighted summation, using the formula:

[0116] ;

[0117] to obtain the local corrosion rate distribution value;

[0118] wherein, represents the local corrosion rate distribution value, represents the change amount of current at the th microelectrode position, represents the distance between the th microelectrode and the adjacent microelectrode, is the number of microelectrodes.

[0119] First, calculate the gradient distribution value of each microelectrode, and obtain the microelectrode spacing and the change amount of transient current , and calculate the local corrosion rate through weighted summation, setting the formula:

[0120] ;

[0121] wherein, take , and use and in Table 2 for calculation:

[0122] ;

[0123] Finally, obtain the local corrosion rate distribution value , which reflects the local corrosion rate situation. A higher value indicates a faster corrosion rate in this area. Subsequently, the microelectrode spacing can be further optimized to improve the detection accuracy.

[0124] Please refer to Figure 4 , the corrosion rate calculation module includes:

[0125] The current change analysis sub-module collects the current response data on the pipeline surface based on the transient current change amount and the local corrosion rate distribution value, calculates the amplitude change rate of the current response per unit time, analyzes the change trend of the current response over time, and obtains the amplitude change rate of the current response;

[0126] First, collect the current response data on the pipeline surface. This process usually uses high-precision sensors such as electrochemical noise sensors or potentiostats to obtain transient current signals through multiple measurement points distributed on the pipeline surface. Subsequently, normalize the collected data to eliminate external interference signals. The normalization calculation process can adopt the mean normalization method, that is, for the transient current at a certain moment of the transient current , the normalization calculation formula is , where and are the minimum and maximum transient current values within this time window respectively. The normalized data is further filtered. Sliding average filtering or wavelet transform can be used to remove noise. Based on the filtered data, calculate the amplitude change rate of the current response per unit time. This calculation involves taking the difference operation on the current signals at adjacent time points, that is, for two consecutive time points and , the calculation of the current response change amount is . Given the known time increment , the formula for calculating the amplitude change rate of the current response per unit time can be , where is the current change rate. After calculating for all measurement points, the overall current change trend can be represented by calculating its mean value , where is the number of measurement points. Furthermore, through trend fitting methods, such as polynomial fitting or exponential smoothing methods, fit the change trend of the current response over time to obtain the time evolution law of the amplitude change rate of the current response.

[0127] The corrosion current density calculation sub-module calls the amplitude change rate of the current response, combines the electrochemical characteristics of the pipeline material, calculates the charge transfer relationship in the local area during the corrosion process, and uses the formula:

[0128] ;

[0129] Calculate the current density per unit area during the corrosion process through the operation to obtain the corrosion current density;

[0130] Among them, represents the corrosion current density, represents the change amount of the current response per unit time, represents the measurement area represents the charge transfer coefficient represents the measurement time;

[0131] First, it is necessary to obtain the electrochemical characteristic parameters of the pipeline material, including the exchange current density of the material , the Tafel slope and the redox potential of the metal . These parameters are usually obtained through experimental measurements. For example, electrochemical impedance spectroscopy (EIS) tests or Tafel curve measurements are used. Subsequently, the rate of change of the current response amplitude is used to calculate the amount of charge transfer per unit time. This value can be calculated by the formula , where is the measurement area is the measurement time. The calculated charge transfer amount is used to further solve for the corrosion current density . According to the formula , where the charge transfer coefficient is usually determined based on the polarization curve experiment of the material, and its value range is usually between 0.3 and 0.7. For example, for pipeline steel of grade X60, experimentally measured . Assuming a certain measurement area , the measurement time , and the measured value of the change in current response per unit time is 2.5 mA, then the corrosion current density is calculated as follows:

[0132] ;

[0133] ;

[0134] This value reflects the magnitude of the corrosion current density occurring per unit area and indicates the severity of the corrosion. Subsequently, this calculation result can be used for further analysis of the corrosion rate trend.

[0135] The corrosion rate trend calculation sub-module calls the corrosion current density, combines it with the polarization curve parameters of the material, calculates the dynamic change trend of the corrosion rate per unit time, adjusts the measurement rate increment, and obtains the dynamic change value of the corrosion rate.

[0136] First, it is necessary to obtain the electrochemical polarization parameters of the material, including the anodic Tafel slope and the cathodic Tafel slope . These parameters are usually determined by experiments. For example, for X60 pipeline steel, measured , , based on the current density calculate the corrosion rate , calculated using Faraday's law:

[0137] ;

[0138] where is the molar mass of the metal (such as iron ), is the number of charges (when iron corrodes ), is the Faraday constant ( ), is the metal density (the density of iron ), and substituting obtained from the above calculation for calculation:

[0139] ;

[0140] ;

[0141] The calculation result represents the change trend of the corrosion rate. Subsequently, the measurement rate increment is adjusted to optimize the dynamic change value of the corrosion rate, that is, the change of is calculated in different time intervals, and its relative change rate is calculated:

[0142] ;

[0143] If the corrosion rate at a certain moment is measured as , and when the corrosion rate is measured as , then:

[0144] ;

[0145] This value is used to evaluate the change trend of the corrosion rate. Combining with long-term monitoring data, it can be used to predict the development trend of corrosion.

[0146] Please refer to Figure 5 , the corrosion risk distribution analysis module includes:

[0147] The corrosion rate distribution calculation sub-module, based on the dynamic change value of the corrosion rate, obtains the corrosion rate data at multiple locations in the region, calculates the change rate of the corrosion rate between adjacent locations, constructs the distribution matrix of the corrosion rate change in multiple regions, calculates the corrosion rate gradient at multiple points, and generates the corrosion rate gradient matrix;

[0148] First, deploy multiple monitoring points within the selected area. Each monitoring point collects corrosion rate data through a sensing device. The data collection frequency is set according to the device accuracy. For example, high-precision devices can be set to once per minute, while ordinary-precision devices can be set to once per hour. The collected data is stored in the database after normalization. For the data of adjacent monitoring points, a change curve is plotted with time as the abscissa and the corrosion rate as the ordinate, and the corrosion rate change rate between every two adjacent points is calculated. The calculation formula is , where is the corrosion rate at the th position, is the corresponding timestamp. After storing the change rate data, a corrosion rate change distribution matrix within the area is constructed. The size of the matrix is , where represents the number of rows, corresponding to the number of monitoring points in the vertical direction, represents the number of columns, corresponding to the number of monitoring points in the horizontal direction. Based on the distribution matrix, the multi-point corrosion rate gradient is calculated. The gradient calculation uses the numerical differentiation method, that is and calculate the gradient values in the horizontal and vertical directions respectively, and the Euclidean norm is used to calculate the comprehensive gradient . The calculated gradient data is stored in the gradient matrix, and the size of the matrix is the same as that of the distribution matrix, as shown in Table 5

[0149] Table 5 Corrosion Rate Gradient Matrix

[0150]

[0151] As shown in Table 5, the corrosion rate gradient matrix can clearly reflect the corrosion rate change situation of each point within the area, and finally obtain the corrosion rate gradient matrix

[0152] The ratio exceeding standard area identification sub-module calls the corrosion rate gradient matrix, calculates the local ratio of the corrosion rate change rate in multiple areas, sets a threshold, screens the areas where the ratio exceeds the standard, and calculates the distribution characteristics to obtain the distribution parameters of the exceeded standard areas

[0153] For each area, calculate the local corrosion rate change rate ratio. The calculation method is , where is the average corrosion rate gradient of the area. Set the exceeded standard threshold . If , then it is determined that the area exceeds the standard. The threshold usually depends on industry standards or experimental measurement values. For example, if the average corrosion rate gradient of a certain area is 0.15 mm / a and is set, then the exceeded standard corrosion rate threshold is mm / a, select the qualified areas as the exceeded-standard areas, and count the distribution parameters of the exceeded-standard areas, including the number of exceeded-standard areas, the area ratio, and the maximum-minimum corrosion gradient ratio, as shown in Table 6.

[0154] Table 6 Distribution parameters of exceeded-standard areas

[0155]

[0156] As shown in Table 6, by calculating the distribution parameters of the exceeded-standard areas, the specific distribution information of the exceeded-standard areas can be obtained.

[0157] The hot-spot range gradient calculation sub-module calls the distribution parameters of the exceeded-standard areas, adjusts the scanning step size, compares the corrosion rate change gradients of local areas, and uses the formula:

[0158] ;

[0159] Calculate to obtain the corrosion hot-spot distribution parameters;

[0160] Among them, represents the corrosion hot-spot distribution parameter, represents the th corrosion rate gradient value at the th position, represents the scanning step size at the th position, represents the exceeded-standard ratio of the th area, represents the difference degree of the corrosion rate gradients in the neighborhood of the th area,

[0161] First, set the scanning step size as a fixed value, such as 0.5 m, scan each exceeded-standard area in turn, compare the corrosion rate change gradients of local areas, and the calculation formula is:

[0162] ;

[0163] Among them, is the th corrosion rate gradient value at the th position, obtained from the gradient matrix, is the scanning step size, set to 0.5 m, is the exceeded-standard ratio, obtained from the ratio exceeded-standard area identification sub-module,

[0164] ;

[0165] Among them is the number of monitoring points in the neighborhood, calculate When the value is such that there are 3 over-standard points in the assumed area, and its parameters are as follows: - mm / a, , - mm / a, , - mm / a, , ;

[0166] Substitute into the formula:

[0167] ;

[0168] Calculate each item:

[0169] ;

[0170] ;

[0171] ;

[0172] ;

[0173] The result shows that the corrosion hot spot distribution parameter finally calculated , which is used to characterize the corrosion hot spot distribution.

[0174] Please refer to Figure 6 , the environmental parameter compensation module includes:

[0175] The corrosion hot spot distribution calculation sub-module calls the corrosion hot spot distribution parameter, analyzes the change trend of the corrosion intensity in the differential area, obtains the corrosion hot spot distribution data, calculates the pipeline wall thickness change rate according to the distribution data, screens the corrosion intensification area, and calculates the corrosion growth rate data;

[0176] First, read and call the corrosion hot spot distribution parameter, which is calculated from the data collected in the early stage, specifically including the corrosion rate, wall thickness change situation and corresponding time span data in different areas of the pipeline. For example, if the wall thickness of a pipeline area is reduced from 8.5 mm to 8.1 mm in 1 year, the corrosion rate is calculated as mm / year. Subsequently, analyze the corrosion data of multiple monitoring points, compare the wall thickness change rates of each area. If the change rate of a certain area is higher than the preset threshold, it is marked as the corrosion intensification area. The preset threshold can be set according to industry standards. For example, if the set threshold is 0.3 mm / year, and if the wall thickness reduction rate of a certain area is greater than 0.3 mm / year (such as 0.35 mm / year), then it is considered that the corrosion in this area is intensifying. Screen the corrosion hot spot distribution data of the corrosion intensification area and calculate its corrosion growth rate. The specific calculation method can adopt the growth rate formula:

[0177] ;

[0178] wherein, is the corrosion growth rate, and respectively represent the corrosion rates at time and . If mm / year, mm / year, and the time interval years, then the calculation result is mm / year 2 , and finally the corrosion growth rate data is obtained.

[0179] Based on the corrosion growth rate data, the operation environment monitoring sub-module monitors the temperature, pressure and flow rate of the pipeline operation environment, collects the operation parameters corresponding to the corresponding time period, and at the same time compares the change range of the operation parameters, calculates the temperature-flow rate co-influence factor, and uses the formula:

[0180] ;

[0181] The temperature-flow rate co-influence factor data is obtained through operation to obtain the environmental influence coefficient;

[0182] wherein, represents the temperature-flow rate co-influence factor, , are respectively the maximum and minimum values of the operation temperature, , are respectively the maximum and minimum values of the operation flow rate, is the average pressure within the time period, is the set of corrosion influence coefficients corresponding to the corrosion growth rate data, is the number of selected corrosion hot spots;

[0183] Formula:

[0184] ;

[0185] First, based on the corrosion growth rate data, identify the key pipeline areas that need to be monitored, and deploy sensors in these areas to collect temperature, pressure and flow rate data respectively. For example, the temperature range recorded by a certain monitoring point within 1 hour is and , the flow rate range is m / s and m / s, and the average pressure is obtained by taking the average value of the pressure data in the same time period, such as 4.5 MPa, and the corrosion influence coefficient Based on the acquisition of corrosion growth rate data, if the corrosion growth rate in a certain area is relatively high, its is set to 0.6. Then calculate the temperature-flow rate co-influence factor:

[0186] ;

[0187] Obtain the environmental influence coefficient , indicating that the temperature and flow rate in this area fluctuate greatly and have a strong influence on the corrosion rate.

[0188] The disturbance amplitude adjustment sub-module calls the environmental influence coefficient, analyzes the disturbance influence range, calculates the disturbance correction value according to the environmental influence coefficient, adjusts the disturbance amplitude, determines the disturbance adjustment interval, and calculates and obtains the environmental parameter compensation correction value.

[0189] First, call the calculated environmental influence coefficient to judge the influence range of the environment on corrosion. For example, if it shows that the environmental disturbance is large, and it may be necessary to increase the adjustment interval and correction amplitude. Set the reference disturbance correction value to 0.05, and the calculation formula is as follows:

[0190] ;

[0191] Substitute for calculation:

[0192] ;

[0193] Then the disturbance correction value is 0.249. Subsequently, adjust the disturbance amplitude, that is, perform smoothing processing on the monitoring data. For example, use the sliding window average method to calculate the average temperature and flow rate within 10 hours before and after adjustment, adjust the disturbance interval, calculate and obtain the environmental parameter compensation correction value. For example, the temperature correction value is 2.1°C, and the flow rate correction value is 0.15 m / s. Finally, ensure that the calculated compensation correction value can accurately match the corrosion environment of the pipeline.

[0194] Table 7 Example of monitoring data

[0195]

[0196] As shown in Table 7, there are differences in temperature, flow rate, pressure and corrosion influence coefficient at different monitoring points. These parameters all affect the finally calculated temperature-flow rate co-influence factor, and further guide the disturbance correction and environmental parameter compensation calculation.

[0197] The above are only the preferred embodiments of the present invention, and do not limit the present invention in other forms. Any person skilled in the relevant art may use the technical content disclosed above to make changes or modifications into equivalent embodiments with equivalent changes and apply them to other fields. However, as long as it does not depart from the technical solution content of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. An intelligent pipeline corrosion monitoring and protection system, characterized in that: The system comprises: The dynamic potential disturbance measurement module obtains the reference potential on the pipeline surface, controls the potential source to apply instantaneous disturbance, adjusts the disturbance amplitude and records the current changes before and after the disturbance, and obtains the transient current change by differential operation; The local micro-area scanning module arranges a microelectrode array based on the transient current variation, adjusts the microelectrode position to cover the hot spot, records the local current response, calculates the distribution gradient, and obtains the local corrosion rate distribution value; The corrosion rate calculation module calculates the current response amplitude change rate according to the transient current change and the local corrosion rate distribution value, calculates the corrosion current density in combination with the electrochemical characteristics of the pipeline material, calculates the dynamic change of the corrosion rate, calculates the time series according to the change, adjusts the measurement rate increment, and obtains the dynamic change value of the corrosion rate; The corrosion risk distribution analysis module calculates the corrosion rate change in the region according to the dynamic change value of the corrosion rate, analyzes the local ratio exceeding the standard area, adjusts the scanning step length, calculates the hot spot range gradient, and obtains the corrosion hot spot distribution parameters; The environmental parameter compensation module calls the corrosion hot spot distribution parameters, monitors the temperature, pressure and flow rate of the pipeline operation environment, calculates the environmental impact, and adjusts the disturbance amplitude and interval.

2. The intelligent pipeline corrosion monitoring and protection system according to claim 1 is characterized in that: The transient current change includes the disturbance amplitude, the current before the disturbance, and the current after the disturbance. The local corrosion rate distribution value is specifically the local current response and the distribution gradient. The dynamic change value of the corrosion rate includes the current response amplitude change rate, the corrosion current density, the dynamic change of the corrosion rate, and the measured rate increment. The corrosion hotspot distribution parameters specifically refer to the regional corrosion rate change, the local ratio exceeding the standard area, the scanning step size, and the hotspot range gradient.

3. The intelligent pipeline corrosion monitoring and protection system according to claim 2 is characterized in that: The dynamic potential perturbation measurement module comprises: The reference potential acquisition submodule acquires the pipeline surface potential, calls the reference electrode outside the pipeline to detect the reference potential, screens the potential data at different time points, calculates the potential fluctuation range, and selects the measured value in the potential stability interval as the pipeline surface reference potential; The disturbance potential applying submodule controls the potential source to output the instantaneous potential disturbance of the target amplitude based on the pipeline surface reference potential, adjusts the disturbance amplitude and records the current change on the pipeline surface after the disturbance, selects the disturbance data with stable current fluctuation value, and obtains the current change before and after the disturbance; The transient current calculation submodule uses the formula based on the current change before and after the disturbance: ； Obtain the transient current change trend in multiple time periods, calculate and establish the transient current change; in, Represents the instantaneous current change, Represents the first Current value at the moment, Represents the first Current value at the moment, Represents the number of time segments, represents the applied perturbation potential, represents the reference potential of the pipeline surface, Represents the equivalent resistance of the pipe surface.

4. The intelligent pipeline corrosion monitoring and protection system according to claim 3 is characterized in that: The local micro-area scanning module comprises: The microelectrode arrangement submodule arranges the microelectrode array based on the transient current variation, detects the distribution of the transient current variation, determines the area with a large current variation, adjusts the microelectrode position to cover the hotspot, and generates a hotspot covering arrangement state; The current response recording submodule calls the hotspot coverage layout state, records the local current response, obtains transient current data at the multi-microelectrode positions, calculates the current response gradient distribution, and generates a current gradient distribution value; The local corrosion rate calculation submodule calculates the distribution gradient based on the current gradient distribution value, obtains the microelectrode spacing, transient current change and current gradient distribution value, performs gradient calculation and weighted summation, and adopts the formula: ； Get the local corrosion rate distribution value; in, represents the local corrosion rate distribution value, Representative The current change at each microelectrode position is Representative The distance between each microelectrode and the adjacent microelectrode, is the number of microelectrodes.

5. The intelligent pipeline corrosion monitoring and protection system according to claim 4 is characterized in that: The corrosion rate calculation module includes: The current change analysis submodule collects the current response data on the pipeline surface based on the transient current change and the local corrosion rate distribution value, calculates the amplitude change rate of the current response per unit time, analyzes the change trend of the current response over time, and obtains the current response amplitude change rate; The corrosion current density calculation submodule calls the current response amplitude change rate, combines the electrochemical characteristics of the pipeline material, and calculates the charge transfer relationship in the local area during the corrosion process using the formula: ； The current density per unit area during the corrosion process is calculated to obtain the corrosion current density; in, represents the corrosion current density, Represents the change in current response per unit time, Represents the measurement area, represents the charge transfer coefficient, represents the measurement time; The corrosion rate trend calculation submodule calls the corrosion current density, combines the polarization curve parameters of the material, calculates the dynamic change trend of the corrosion rate per unit time, adjusts the measurement rate increment, and obtains the dynamic change value of the corrosion rate.

6. The intelligent pipeline corrosion monitoring and protection system according to claim 5 is characterized in that: The corrosion risk distribution analysis module includes: The corrosion rate distribution calculation submodule obtains the corrosion rate data of multiple positions in the region based on the dynamic change value of the corrosion rate, calculates the corrosion rate change rate between adjacent positions, and constructs a distribution matrix of the corrosion rate changes in multiple regions, calculates the corrosion rate gradients of multiple points, and generates a corrosion rate gradient matrix; The ratio exceeding standard region identification submodule calls the corrosion rate gradient matrix, calculates the local ratio of the corrosion rate change rate in multiple regions, sets a threshold, screens the regions where the ratio exceeds the standard, calculates the distribution characteristics, and obtains the distribution parameters of the exceeding standard regions; The hotspot range gradient calculation submodule calls the distribution parameters of the exceeding area, adjusts the scanning step length, compares the corrosion rate change gradient of the local area, and uses the formula: ； Calculate and obtain the distribution parameters of corrosion hot spots; in, represents the corrosion hotspot distribution parameter, Representative The corrosion rate gradient value at each location is Representative The scanning step length of the positions, Representative The excess ratio of each region, Representative The difference in the gradient of the neighborhood corrosion rate of each region, Represents the total number of calculation points in the region.

7. The intelligent pipeline corrosion monitoring and protection system according to claim 6 is characterized in that: The environmental parameter compensation module comprises: The corrosion hotspot distribution calculation submodule calls the corrosion hotspot distribution parameters, analyzes the corrosion intensity change trend of the differentiated area, obtains the corrosion hotspot distribution data, calculates the pipeline wall thickness change rate according to the distribution data, screens the corrosion aggravation area, and calculates the corrosion growth rate data; The operating environment monitoring submodule monitors the temperature, pressure and flow rate of the pipeline operating environment based on the corrosion growth rate data, collects the operating parameters of the corresponding time period, and compares the variation range of the operating parameters to calculate the temperature-flow rate synergistic influence factor using the formula: ； Calculate and obtain the temperature-flow rate synergistic impact factor data to obtain the environmental impact coefficient; in, represents the temperature-flow rate synergistic influence factor, , are the maximum and minimum operating temperatures, respectively. , are the maximum and minimum values ​​of the operating flow rate, is the average pressure during the time period, is the set of corrosion influence coefficients corresponding to the corrosion growth rate data, is the number of selected corrosion hotspot areas; The disturbance amplitude adjustment submodule calls the environmental impact coefficient, analyzes the disturbance impact range, calculates the disturbance correction value according to the environmental impact coefficient, adjusts the disturbance amplitude, determines the disturbance adjustment interval, and calculates and obtains the environmental parameter compensation correction value.

8. The intelligent pipeline corrosion monitoring and protection system according to claim 7 is characterized in that: The intelligent pipeline corrosion monitoring and protection system also includes a corrosion protection control module; The corrosion protection control module intelligently adjusts the cathodic protection current or sacrificial anode configuration according to the corrosion hotspot distribution parameters and the dynamic change value of the corrosion rate, optimizes the corrosion protection measures, and dynamically adjusts the protection strategy to reduce the corrosion risk.

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