A method of testing a pipe condition and an electronic device

Abstract

A method and electronic device for testing pipeline conditions are disclosed. The method includes performing AC impedance spectroscopy on a working electrode placed inside a pipeline under test according to different scanning parameters to determine the impedance type of scale in the pipeline under test. The working electrode is made from pipe material cut from the pipeline under test and its inner scale, or from the same metal material as the pipeline under test. The working electrode is then subjected to AC impedance spectroscopy again using scanning parameters adapted to the obtained impedance type of the scale in the pipeline under test. The test results are then fitted using an appropriate equivalent circuit to obtain scale characteristic test data. This effectively ensures the fitting of the characterization method, thereby reducing fitting errors and improving the accuracy of pipeline condition test data.

Description

Technical Field

[0001] This article relates to electrochemical testing techniques for pipelines, and more particularly to a testing method and electronic equipment for pipeline conditions. Background Technology

[0002] Water supply is one of the lifeline projects of a city. However, during actual operation, pipelines can experience secondary pollution due to complex chemical reactions, resulting in increased turbidity and color, or even "yellow water." Therefore, pipeline testing is often necessary to understand the pipeline's condition.

[0003] In related technologies, electrochemical impedance spectroscopy is commonly used to test and obtain information about pipeline conditions.

[0004] However, the electrochemical impedance spectroscopy method used in related technologies to obtain pipeline conditions only uses scanning parameters that include a single scanning frequency range. In actual applications, the scale on pipelines varies greatly, which often leads to a large fitting error, resulting in low accuracy of the obtained pipeline condition test data. Summary of the Invention

[0005] This application provides a method and electronic device for testing pipeline conditions, which can greatly reduce fitting errors and improve the accuracy of pipeline condition test data.

[0006] This application provides a method for testing pipeline conditions, the method comprising:

[0007] AC impedance spectroscopy is performed on the working electrode placed inside the pipe under test according to different scanning parameters to determine the impedance type of the scale in the pipe under test; wherein, the working electrode is made of pipe material cut from the pipe under test and the scale inside it, or is made of the same metal material as the pipe under test.

[0008] The working electrode is subjected to AC impedance spectroscopy again using scanning parameters adapted to the impedance type of the scale in the pipe under test, and the test results are fitted with an appropriate equivalent circuit to obtain scale characteristic test data.

[0009] This application also provides an electronic device, including: a memory and a processor;

[0010] The memory is connected to the processor and is used to store programs;

[0011] The processor is configured to implement the pipeline testing method described above by running the program in the memory.

[0012] This application embodiment includes performing AC impedance spectroscopy on a working electrode placed inside a pipe under test according to different scanning parameters to determine the impedance type of scale in the pipe under test. The working electrode is manufactured from pipe material cut from the pipe under test and its inner scale, or from the same metal material as the pipe under test. The working electrode is then subjected to AC impedance spectroscopy again using scanning parameters adapted to the obtained impedance type of the scale in the pipe under test, and the test results are fitted using an appropriate equivalent circuit to obtain scale characteristic test data. Therefore, the fitting of the characterization method is effectively guaranteed, thereby reducing fitting errors and improving the accuracy of pipe condition test data.

[0013] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the embodiments described in the description and the accompanying drawings. Attached Figure Description

[0014] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0015] Figure 1 This is a schematic flowchart illustrating a method for testing pipeline conditions according to an embodiment of this application;

[0016] Figure 2 This is a schematic diagram illustrating a process for determining the impedance type of scale in a pipe under test according to an embodiment of this application;

[0017] Figure 3 This is a schematic diagram of the structure of a first equivalent circuit according to an embodiment of this application;

[0018] Figure 4 This is a schematic diagram illustrating a process for obtaining pipe scale characteristic test data according to an embodiment of this application;

[0019] Figure 5 This is a schematic diagram of the structure of a second equivalent circuit according to an embodiment of this application;

[0020] Figure 6 This is a schematic diagram illustrating another process for obtaining pipe scale characteristic test data according to an embodiment of this application;

[0021] Figure 7 This is a schematic diagram of the structure of a third equivalent circuit according to an embodiment of this application;

[0022] Figure 8 This is a schematic diagram of a segmented AC impedance spectroscopy test process according to an embodiment of this application;

[0023] Figure 9 This is a schematic diagram of the structure of a pipeline condition testing device according to an embodiment of this application;

[0024] Figure 10 This is a schematic diagram of the structure of an electronic device according to an embodiment of this application. Detailed Implementation

[0025] This application describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0026] This application includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this application can also be combined with any conventional features or elements to form unique inventive solutions. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution. Therefore, it should be understood that any feature shown and / or discussed in this application can be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims.

[0027] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0028] Water supply is one of the lifelines of urban infrastructure. Even qualified treated water can experience secondary pollution during its transport through pipe networks due to complex chemical reactions, leading to increased turbidity and color, and even "yellow water." In commonly used iron pipes, elemental iron acts as an electron donor, reacting with oxidizing substances in the water to produce corrosion products, primarily iron oxides. The formation of scale is the result of the continuous deposition and oxidation of these corrosion products. Normally, the incoming water and the stable corrosion products that have formed over time maintain an equilibrium. However, changes in the quality of the incoming water or the hydraulic conditions of the pipe network can disrupt this equilibrium, releasing iron corrosion products from the pipe sections and jeopardizing water supply safety.

[0029] The scale formed on the inner wall of iron water supply pipes has a significant layered structure, including (1) a metal base layer, (2) a porous layer composed of loose ferrous and ferric oxides, (3) a dense hard shell layer mainly composed of iron(II,III) oxide (Fe3O4), and (4) an outermost layer of red deposits mainly composed of amorphous iron oxides such as iron hydroxide, silicates, and carbonates. Each of these layers has different electrochemical characteristics. The loose red rust on the outermost layer of scale is an electronic insulator, but it has no significant kinetic effect on reactions directly involving ions. The dense layer mainly composed of iron(II,III) oxide has a very high impedance, but corrosion current still exists in some areas with crystal defects and cracks. The inner layer of scale is a loose rust product with very large pores and has good conductivity. The surface of the pipe substrate is the main site for electrochemical reactions and charge transfer, with a high charge accumulation and a high capacitive reactance. The differences in the structure and impedance characteristics of different layers of scale lead to different formation and rupture mechanisms.

[0030] Since the corrosion process of pipe sections is mainly an electrochemical reaction, and the structure and charge migration characteristics of pipe scale can be expressed by the pipe scale impedance value, the corrosion process and changes in the pipe scale structure of water supply pipelines can be monitored by testing the impedance and electrochemical signals such as corrosion current and voltage of pipe scale.

[0031] Electrochemical testing, as an in-situ monitoring method, offers real-time and agile signal responses. Electrochemical techniques for detecting corrosion of iron-based materials in drinking water networks include alternating current impedance spectroscopy (ACIS). ACIS is a method for measuring the impedance characteristics of metallic materials. This method applies a small sinusoidal alternating current to the surface of a metal electrode, which scans within a specific frequency range, continuously recording resistance and reactance signals. Since the accumulation of reaction products on the surface of the metal substrate significantly affects the electrochemical reaction process, the obtained impedance signal corresponds to the structural information of the scale-solution, scale, and scale-substrate interfaces. The analysis results of ACIS can be further abstracted into equivalent circuits. For the multilayer structure of scale, the ACIS measurement results can be well fitted to equivalent circuits with multi-level time parameters. The impedance data reflects various physical quantities such as charge migration and diffusion, charge interaction, and porosity, accurately characterizing the structural features and electrochemical processes within different layers and at interfaces.

[0032] However, the electrochemical impedance spectroscopy method used in related technologies to obtain pipeline conditions only uses scanning parameters that include a single scanning frequency range. In actual applications, the scale on pipelines varies greatly, which often leads to a large fitting error, resulting in low accuracy of the obtained pipeline condition test data.

[0033] Therefore, this disclosure provides a method for testing pipeline conditions, such as... Figure 1 As shown, it includes:

[0034] Step 100: Perform AC impedance spectroscopy on the working electrode placed inside the pipe under test according to different scanning parameters to determine the impedance type of the scale in the pipe under test; wherein, the working electrode is made from the pipe material cut from the pipe under test and the scale inside it, or is made from the same metal material as the pipe under test.

[0035] Step 110: Perform AC impedance spectroscopy on the working electrode again using scanning parameters that are compatible with the impedance type of the scale in the pipe to be tested, and fit the test results with an appropriate equivalent circuit to obtain scale characteristic test data.

[0036] The working electrode consists of a platinum auxiliary electrode and an Ag / AgCl reference electrode for electrochemical testing. The electrode working surface is located inside the water supply pipe to obtain electrochemical signals. The electrode tip is connected to an electrochemical workstation and a computer via wires to perform electrochemical tests.

[0037] The pipeline condition testing method provided in this application involves performing AC impedance spectroscopy on a working electrode placed inside the pipeline under test using different scanning parameters to determine the impedance type of scale in the pipeline. The working electrode is manufactured from pipe material cut from the pipeline under test and its inner scale, or from the same metal material as the pipeline under test. The working electrode is then subjected to AC impedance spectroscopy again using scanning parameters adapted to the obtained impedance type of the scale in the pipeline, and the test results are fitted using an appropriate equivalent circuit to obtain scale characteristic test data. Therefore, this method effectively ensures the fitting of the characterization method, thereby reducing fitting errors and improving the accuracy of pipeline condition test data.

[0038] In one exemplary instance, the scanning parameters include: scanning frequency range, scanning mode, and scanning amplitude, such as... Figure 2 As shown, AC impedance spectroscopy is performed on the working electrode placed inside the pipe under test according to different scanning parameters to determine the impedance type of scale in the pipe under test, including:

[0039] Step 200: Scan the working electrode at each frequency with a first scanning frequency range, a first scanning mode, and a first scanning amplitude to obtain a first Nyquist plot; wherein, the first scanning frequency range includes a frequency range from a first frequency to a second frequency, and the first frequency is less than the second frequency;

[0040] Step 210: Scan the working electrode at each frequency using the second scanning frequency range, the second scanning mode, and the second scanning amplitude to obtain the second Nyquist plot; wherein, the second scanning frequency range includes a frequency range from the third frequency to the first frequency, the third frequency is less than the first frequency, and the density of the scanning points selected in the first scanning mode is greater than the density of the scanning points selected in the second scanning mode.

[0041] Step 220: Merge the first Nyquist plot and the second Nyquist plot to obtain the third Nyquist plot, and obtain the frequency within the first frequency interval that minimizes the imaginary part of the third Nyquist plot as the target frequency; wherein, the first frequency interval is the frequency interval of the third Nyquist plot.

[0042] Step 230: Fit the third Nyquist plot within the second frequency range to the first equivalent circuit, and obtain the preliminary double-layer capacitor constant phase angle element CPE′ through iterative calculation. dl and initial charge transfer resistance R′ ct ;

[0043] The first equivalent circuit diagram is a simplified circuit diagram, used only for quickly estimating and obtaining the constant phase angle element of the double-layer capacitor and the charge transfer resistor within a short test time. The rapidly estimated constant phase angle element of the double-layer capacitor is denoted as the preliminary constant phase angle element of the double-layer capacitor CPE′. dl The charge transfer resistance obtained by rapid estimation is denoted as the preliminary charge transfer resistance R′. ct Preliminary double-layer capacitor constant phase angle element CPE′ dl and initial charge transfer resistance R′ ct These two differ from the double-layer capacitor constant phase angle element CPE precisely calculated in the embodiments of this application. dl and charge transfer resistance R ct Preliminary double-layer capacitor constant phase angle element CPE′ dl and initial charge transfer resistance R′ ct It is only used to calculate and determine whether the impedance type of the scale in the pipe under test is the first impedance type or the second impedance type, so as to adopt different testing strategies in the future.

[0044] Step 240: Based on the calculated preliminary double-layer capacitor constant phase angle element CPE′ dl and initial charge transfer resistance R′ ct Determine the impedance type of scale in the pipe under test;

[0045] The second frequency range is the frequency range including the target frequency to the third frequency; the first equivalent circuit is the preliminary scale film resistor R. f ′ and initial charge transfer resistance R′ ct Series connection, and initial charge transfer resistance R′ ct With the initial electric double-layer capacitor constant phase angle element CPE′ dl The equivalent circuit obtained by parallel connection.

[0046] The Nyquist plot refers to the curve of the real part of impedance Z' minus the imaginary part of impedance Z”. Merging different Nyquist plots means merging different curves of the real part of impedance Z' minus the imaginary part of impedance Z”.

[0047] The first equivalent circuit can be described as follows: Preliminary scale film resistance R f One end of the first node 11 is connected to the initial charge transfer resistor R′. ct One end is connected to the first node 11, and the other end is connected to the second node 12. This is the initial double-layer capacitor constant phase angle element CPE′. dl One end is connected to the first node 11, and the other end is connected to the second node 12. The first equivalent circuit can be as follows: Figure 3 As shown.

[0048] Because the first scanning frequency range is higher than the second scanning frequency range, the density of scan points selected in the second scanning mode can be less than that selected in the first scanning mode. Otherwise, the scanning time may be too long when scanning in the second scanning mode within the second scanning frequency range. For example, if the first scanning mode is 10 points / 10 times the frequency, the second scanning mode can be 5 points / 10 times the frequency. In this way, the scanning time consumed by scanning in the first scanning mode within the first scanning frequency range will not differ significantly from the scanning time consumed by scanning in the second scanning mode within the second scanning frequency range.

[0049] In one exemplary instance, the initial double-layer capacitor constant phase angle element CPE′ dl Includes: preliminary double-layer capacitance C′ dl The power term α′ of the initial double-layer constant phase angle element dl The impedance types of scale in the pipe under test include a first impedance type and a second impedance type, and the impedance of the first impedance type is lower than that of the second impedance type.

[0050] Based on the calculated preliminary double-layer capacitor constant phase angle element CPE′ dl and initial charge transfer resistance R′ ct Determine the impedance type of scale in the pipe under test, including:

[0051] Calculate separately and Where i is the imaginary unit, and ω is the angular frequency obtained from the target frequency;

[0052] exist In this case, the impedance type of the scale in the pipe under test is determined to be the first impedance type;

[0053] exist In this case, the impedance type of the scale in the pipe under test is determined to be the second impedance type.

[0054] Taking the target frequency as f1 as an example, ω = 2πf1.

[0055] In one exemplary instance, such as Figure 4 As shown, the working electrode is subjected to AC impedance spectroscopy again using scanning parameters adapted to the impedance type of the scale in the pipe under test. The test results are then fitted using an appropriate equivalent circuit to obtain characteristic test data of the scale, including:

[0056] Step 300: If the pipe scale is determined to be of the first impedance type, a fourth Nyquist plot is obtained by scanning at each frequency using the second scanning frequency range, the third scanning mode, and the third scanning amplitude; wherein the density of the scanning points selected in the third scanning mode is greater than the density of the scanning points selected in the second scanning mode.

[0057] Step 310: Merge the first Nyquist plot and the fourth Nyquist plot to obtain the fifth Nyquist plot;

[0058] Step 320: Fit the fifth Nyquist plot to the second equivalent circuit, and obtain the scale film resistance R through iterative calculation. f , Pipe scale membrane capacitance C f Charge transfer resistance R ct and double-layer capacitance C dl ;

[0059] The second equivalent circuit is the solution resistance R. s , pipe scale film resistance R f Charge transfer resistance R ct They are connected in series, and the charge transfer resistance R ct With double-layer capacitors, constant phase angle element CPE dl Parallel connection, and the scale film capacitor is a constant phase angle element CPE. f With the resistance R of the scale film f Charge transfer resistance R ct Equivalent circuit in parallel.

[0060] Pipe scale film capacitor constant phase angle element CPE f With the resistance R of the scale film f Charge transfer resistance R ct Parallel connection refers to: pipe scale film capacitors, constant phase angle elements CPE f With the resistance R of the scale film f Charge transfer resistance R ct The resulting overall parallel connection is not solely related to the scale film resistance R. f In parallel, or alone with charge transfer resistor R ct in parallel.

[0061] The second equivalent circuit can be described as follows: solution resistance R s One end is connected to the third node 13, and the scale film resistance R f One end is connected to the third node 13, and the other end is connected to the fourth node 14. The charge transfer resistor R ct One end is connected to the fourth node 14, and the other end is connected to the fifth node 15. The double-layer capacitor is a constant phase angle element CPE. dl One end is connected to the fourth node 14, and the other end is connected to the sixth node 16. The scale film capacitor is a constant phase angle element CPE.f One end is connected to the third node 13, and the other end is connected to the sixth node 16. The second equivalent circuit can be as follows: Figure 5 As shown.

[0062] If the pipe scale is determined to be of the first impedance type, it indicates that the pipe scale is low impedance scale. In this embodiment, a lower scanning frequency range is used for scanning, and the density of scanning points is increased compared to the density of scanning points selected in the second scanning method to obtain richer scanning information.

[0063] In one exemplary instance, such as Figure 6 As shown, the working electrode is subjected to AC impedance spectroscopy again using scanning parameters adapted to the impedance type of the scale in the pipe under test. The test results are then fitted using an appropriate equivalent circuit to obtain characteristic test data of the scale, including:

[0064] Step 400: If the pipe scale is determined to be of the second impedance type, a scan is performed at each frequency using the third scan frequency range, the fourth scan rate, and the fourth scan amplitude to obtain the sixth Nyquist plot; wherein, the third scan frequency range includes the frequency range from the fourth frequency to the first frequency.

[0065] Step 410: Merge the first Nyquist plot, the second Nyquist plot, and the sixth Nyquist plot to obtain the seventh Nyquist plot;

[0066] Step 420: Fit the sixth Nyquist plot to the third equivalent circuit, and obtain the scale film resistance R through iterative calculation. f , Pipe scale membrane capacitance C f Charge transfer resistance R ct and double-layer capacitance C dl ;

[0067] The third equivalent circuit is the solution resistance R. s , pipe scale film resistance R f Double-layer capacitor constant phase angle element CPE dl The components CPE are connected in series and are constant phase angle elements of the scale film capacitor. f With the resistance R of the scale film f Double-layer capacitor constant phase angle element CPE dl Equivalent circuit in parallel.

[0068] Pipe scale film capacitor constant phase angle element CPE f With the resistance R of the scale film f Double-layer capacitor constant phase angle element CPE d Parallel connection refers to: pipe scale film capacitors, constant phase angle elements CPE f With the resistance R of the scale film fDouble-layer capacitor constant phase angle element CPE dl The resulting overall parallel connection is not solely related to the scale film resistance R. f In parallel, or individually with a double-layer capacitor and a constant phase angle element CPE dl in parallel.

[0069] The third equivalent circuit can be described as follows: solution resistance R s One end is connected to the seventh node 17, and the scale film resistance R f One end is connected to the seventh node 17, and the other end is connected to the constant phase angle element CPE of the double-layer capacitor. dl One end is connected to a double-layer capacitor with constant phase angle element CPE. dl The other end is connected to the eighth node 18, and the scale film capacitor is a constant phase angle element CPE. f One end is connected to the seventh node 17, and the other end is connected to the eighth node 18. The third equivalent circuit can be as follows: Figure 7 As shown.

[0070] In one exemplary instance, the first frequency is 1000Hz, and the second frequency is 5×10⁻⁶. 5 The first scan mode is 10 points / 10 times the frequency, the second scan mode is 2 points / 10 times the frequency, and the third scan mode is 10 points / 10 times the frequency. The amplitudes of the first scan, the second scan, and the third scan are all 10mV.

[0071] If the scanning frequency reaches 10 6 The fitted solution resistance may be negative if the scan frequency reaches 10. 5 But it's less than 5×10 5 The fitted solution resistance has a relatively large error; therefore, the test method for pipeline conditions provided in this application limits the second frequency to 5 × 10⁻⁶. 5 Hz.

[0072] In one exemplary instance, the fourth frequency is 0.001 Hz and the fourth scan amplitude is 10 mV.

[0073] Setting the fourth frequency to 0.001Hz is to ensure the appropriateness of the third scanning frequency range, so as to avoid the problem of excessively long scanning time caused by an excessively large range.

[0074] In one exemplary instance, the method further includes:

[0075] Polarization curves are measured using a working electrode placed inside the pipe under test to obtain the corrosion voltage E, which represents the corrosion status of the pipe's inner wall. corr and corrosion current I corr ;

[0076] In the polarization curve test, the initial voltage is 0.5V lower than the open-circuit voltage and the termination voltage is 0.5V higher than the open-circuit voltage within the scanning range, with a voltage interval of 10mV / s.

[0077] In an aquatic environment, the corrosion voltage and corrosion current of the working electrode can be measured using the polarization curve method, and then the corrosion rate can be obtained according to Faraday's law. The open-circuit voltage of the working electrode can be directly measured, and linear polarization within a voltage range of ΔE can be performed to measure the polarization current ΔI, from which the corrosion current density can be calculated. The Stern–Geary equation (SG) applies:

[0078]

[0079] Where ΔI is the polarization current density (the unit can be μA / cm). 2 ), I corr Corrosion current density (unit: μA / cm) 2 ), ΔE is the polarization voltage difference (unit can be mV), β a β is the anodic polarization constant (the unit can be mV). c This is the cathodic polarization constant (the unit can be mV).

[0080] The corrosion current can be calculated using the SG equation, and then the corrosion rate can be calculated from there.

[0081]

[0082] Where CR is the corrosion rate (unit can be mm / year), C is the metal electrochemical equivalent (unit can be g / eq), and I... corr Corrosion current (unit can be μA / cm) 2 A is the electrode area (unit: cm²). 2 ), d is the metal density (the unit can be g / cm³). 3 )

[0083] The pipeline testing method provided in this application selects a polarization curve test where the initial voltage is 0.5V lower than the open-circuit voltage and the termination voltage is 0.5V higher than the open-circuit voltage, with a voltage interval of 10mV / s.

[0084] In one exemplary instance, the method further includes:

[0085] MS curve testing was performed on the working electrode placed inside the test pipe to obtain the donor charge density N. D Or subject to the main electron density N A ;

[0086] Among them, when the slope of the applied voltage in the MS curve is positive, the donor charge density N is obtained. D When the slope of the applied voltage is negative, the acceptor electron density N is obtained. A In the MS curve test, the initial voltage is 0.7V lower than the open circuit voltage, the termination voltage is 0.3V lower than the open circuit voltage, the voltage frequency is 10kHz, and the voltage step is 0.04V.

[0087] Iron oxides in pipe scale often exhibit strong semiconductor properties due to the presence of numerous crystal defects. Changes in semiconductor type and defect density can reflect variations in the structure and reaction characteristics of the scale. Mott-Schottky (MS) curve analysis is a method for characterizing the semiconductor properties of passivation films on metal surfaces through charge capacitance. Under different applied voltage ranges, the carrier mobility characteristics of the semiconductor differ, exhibiting different capacitance characteristics. Space charge can manifest as an enriched layer, a depletion layer, and a reverse layer. When the space charge is in the depletion layer, according to MS theory, the space charge capacitance C... sc The applied voltage E has the following relationship:

[0088] For n-type semiconductors:

[0089] For p-type semiconductors:

[0090] Where ε is the relative permittivity of the passivation film, and ε0 is the vacuum permittivity (typically 8.854 × 10⁻⁶). -12 F / m), e is the electron charge (usually 1.602 × 10⁻⁶). -19 C), E is the applied voltage (i.e., the voltage difference between the working electrode and the reference electrode), N D With N A These are donor density and acceptor density (units can be cm). -3 E FB Here, k represents the flat-band voltage, and k is the Boltzmann constant (the unit can be 1.38 × 10⁻⁶). -23 J / K), where T is the absolute temperature (unit can be K). At room temperature, kT / e is only about 25mV, so it can usually be ignored. Therefore, we can obtain... It exhibits a linear correlation with E, and the sign of its slope can indicate the semiconductor type. By performing a linear fit with E, the donor N of the semiconductor can be obtained. D Or subject to principal density N A .

[0091] Polarization curves, AC impedance, and MS curves can be used in combination to characterize the corrosion process of metals from the perspective of electrochemical signals such as real-time corrosion voltage and current, structural state of metal surface corrosion products, and charge transfer characteristics. Generally speaking, these electrochemical research methods are mostly applied in materials science and structural mechanics, and have not been seen in practical drinking water supply network systems. Compared with water quality research methods in related technologies, electrochemical methods have advantages such as sensitivity and timeliness. For water companies, timely acquisition of electrochemical signals related to the corrosion process and scale stability of water supply pipelines helps them understand the degree of corrosion and scale status of the pipeline inner wall, thereby assessing the stability risk of the pipeline network and taking relevant control measures in advance to ensure water supply safety. Therefore, establishing a monitoring method for water supply pipeline corrosion and scale stability based on electrochemical analysis has significant practical implications.

[0092] This application also provides a set of index systems for evaluating the corrosion tendency and scale stability of the inner wall of water supply pipelines. This index system includes corrosion voltage E. corr Corrosion current I corr High-resistivity or low-resistivity scale (binary variable), scale film resistance R f , Pipe scale membrane capacitance C f Charge transfer resistance R ct Double-layer capacitance C dl and acceptor charge density N A Or donor electron density N D Isoelectric properties (acceptor charge density N) A Or donor electron density N D The slope of the applied voltage, if positive, represents the donor density N. D If the slope of the applied voltage is negative, then it represents the principal density N. A The above indicators can be obtained by measuring using the aforementioned test methods for corrosion and scale stability of the inner wall of water supply pipelines.

[0093] In this embodiment, the corrosion voltage and corrosion current are obtained using the polarization curve method. The polarization curve test employs a dynamic voltage-current test. The initial voltage of the test scan range is 0.5V lower than the open-circuit voltage, and the termination voltage is 0.5V higher than the open-circuit voltage, with a voltage interval of 10mV / s. The dynamic voltage polarization curve is calculated from the polarization curve test. The Tafel slope can be calculated from this curve to obtain the voltage and current density at which the reduction reaction occurs at the working electrode. These voltage and current densities represent the corrosion voltage E of the inner wall of the pipe. corr and corrosion current I corr .

[0094] In this embodiment of the application, a segmented AC impedance spectroscopy test is also designed, such as... Figure 8As shown, it can be determined whether the scale in the test tube is high-resistance or low-resistance, and the scale film resistance R can be obtained at the same time. f , Pipe scale membrane capacitance C f Charge transfer resistance R ct and double-layer capacitance C dl data.

[0095] The segmented AC impedance spectrum test includes two steps: (1) determining whether the scale is high-impedance or low-impedance; and (2) segmented measurement, curve merging, and equivalent circuit fitting.

[0096] The method for determining whether a pipe has high resistance or low resistance fouling includes the following steps:

[0097] Step 500: Perform impedance-frequency scanning on the working electrode, with a scanning frequency range of 1000Hz-5×10⁻⁶. 5 Hz, the scanning mode is 10 points / 10 times the frequency, the scanning amplitude is 10mV, the measurement time at each scanning frequency is greater than one cycle, and the impedance real part Z'-impedance imaginary part Z” curve 1 is obtained;

[0098] Step 510: Perform impedance-frequency scanning on the working electrode. The scanning frequency range is 0.01Hz-1000Hz, the scanning mode is 2 points / 10 times the frequency, the scanning amplitude is 10mV, and the measurement time at each scanning frequency is greater than one cycle to obtain the impedance real part Z'-impedance imaginary part Z” curve 2.

[0099] Step 520: Merge the impedance real part Z' - impedance imaginary part Z” curve 1 and the impedance real part Z' - impedance imaginary part Z” curve 2 to obtain the impedance real part Z' - impedance imaginary part Z” curve 3, and obtain 0.01Hz - 5×10 5 The frequency f1 within the Hz range that minimizes Z” of the impedance real part Z’ - impedance imaginary part Z” curve 3;

[0100] Step 530: Fit the real part of impedance Z' - imaginary part of impedance Z” curve 3 in the 0.01Hz-f1 interval to the first equivalent circuit, and perform at least 100 iterations using the least squares method to calculate the preliminary double-layer capacitance C′. dl The power term α′ of a preliminary double-layer constant phase angle element dl and initial charge transfer resistance R′ ct ;

[0101] Step 540: Based on the obtained preliminary double-layer capacitance C′ dl The power term α′ of a preliminary double-layer constant phase angle element dl and initial charge transfer resistance R′ ct Determine whether the scale is high-resistance or low-resistance.

[0102] In this step, calculation and like Then it is determined that the scale is high-resistance scale. Then it is determined that the scale is low-resistance scale.

[0103] If the scale is found to be low-impedance scale, the following steps are used to perform equivalent circuit fitting of the AC impedance spectrum to obtain the scale characteristic test data:

[0104] Step 550: Perform impedance-frequency scanning on the working electrode. The scanning frequency range is 0.01Hz-1000Hz, the scanning mode is 10 points / 10 times the frequency, the scanning amplitude is 10mV, and the measurement time at each scanning frequency is greater than one cycle, to obtain the impedance real part Z'-impedance imaginary part Z” curve 4.

[0105] Step 560: Merge the impedance real part Z' - impedance imaginary part Z” curve 1 and the impedance real part Z' - impedance imaginary part Z” curve 4 to obtain the impedance real part Z' - impedance imaginary part Z” curve 5;

[0106] Step 570: Fit the real part of impedance Z' - the imaginary part of impedance Z” curve 5 with the second equivalent circuit, and calculate the scale film resistance R by iterating at least 100 times using the least squares method. f , Pipe scale membrane capacitance C f Charge transfer resistance R ct and double-layer capacitance C dl data.

[0107] If the scale is found to be high-impedance scale, the following steps are used to perform equivalent circuit fitting of the AC impedance spectrum to obtain the scale characteristic test data:

[0108] Step 580: Perform impedance-frequency scanning on the working electrode. The scanning frequency range is 0.001Hz-0.01Hz, the scanning mode is 2 points / 10 times the frequency, the scanning amplitude is 10mV, and the measurement time at each scanning frequency is greater than one cycle, to obtain the impedance real part Z'-impedance imaginary part Z” curve 6.

[0109] Step 590: Merge the impedance real part Z' - impedance imaginary part Z” curve 1, impedance real part Z' - impedance imaginary part Z” curve 2 and impedance real part Z' - impedance imaginary part Z” curve 6 to obtain the impedance real part Z' - impedance imaginary part Z” curve 7;

[0110] Step 510: Fit the real part of impedance Z' - the imaginary part of impedance Z” curve 7 to the third equivalent circuit, and calculate the scale film resistance R by iterating at least 100 times using the least squares method. f , Pipe scale membrane capacitance C f Charge transfer resistance R ct and double-layer capacitance C dl data.

[0111] In this embodiment, the donor or acceptor charge density (donor charge density is obtained if the slope of the applied voltage is positive, and acceptor electron density is obtained if the slope of the applied voltage is negative) can be obtained using a Mott-Schottky curve. The MS curve measurement is an impedance-voltage measurement. In the MS curve test scan range, the initial voltage is 0.7V lower than the open-circuit voltage, the termination voltage is 0.3V lower than the open-circuit voltage, the voltage frequency is 10kHz, and the voltage step is 0.04V. The measured space charge capacitance (C...) is then... sc ) and applied voltage (E) according to By plotting the graph, the donor charge density N can be obtained. D Or subject to the main electron density N A The value of .

[0112] In this embodiment of the application, the proposed electrochemical testing procedure for corrosion and scale stability of the inner wall of the water supply pipeline requires conducting one complete set of tests on each of the following: polarization curve test, segmented AC impedance test, and Mott-Schottky curve test.

[0113] In this embodiment of the application, when conducting tests using the electrochemical testing process for corrosion and scale stability of the inner wall of water supply pipelines, the monitoring frequency can be set according to the conditions of raw water and transported water quality, climate, and surface subsidence, ranging from once a day to once a month. For important pipelines or when water quality and hydraulic conditions fluctuate significantly, online continuous monitoring can be set.

[0114] Through the embodiments of this application, an index system for evaluating the corrosion tendency of the inner wall of water supply pipelines and the stability of scale can be obtained, which can be used to evaluate the chemical stability of the pipeline network and the state of scale. The fluctuation of the index relative to the test benchmark value can characterize the changes in scale structure and composition.

[0115] This application also provides a method for testing pipeline conditions, involving electrode setup and corrosion monitoring of the inner wall of a complete water supply pipeline, including the following steps:

[0116] S.1 Cut the pipe material and its inner scale from the pipe to be tested in situ, or process the same metal material as the pipe to be tested to make a metal working electrode.

[0117] S.2 fabricates an Ag / AgCl reference electrode and a platinum sheet auxiliary electrode with the same working surface area as the working electrode. The electrodes are embedded in the wall of the water supply pipe, with the working surface of the electrodes located inside the water supply pipe. The ends of the electrodes are connected to the electrochemical workstation and computer via wires.

[0118] S.3 The electrode assembly was subjected to the polarization curve test, segmented AC impedance test, and Mott-Schottky curve test, as described above, once each. The corrosion voltage E of the working electrode was obtained through the polarization curve test. corr Corrosion current I corr High-resistivity or low-resistivity scale (expressed as a binary variable), scale film resistance R f , Pipe scale membrane capacitance C f Charge transfer resistance R ct Double-layer capacitance C dl and acceptor charge density N A Or donor electron density N D Electrochemical parameters were measured and their values ​​were recorded.

[0119] S.4 repeats S.3. The monitoring frequency is set according to the raw water and transport water quality, climate, surface subsidence, etc., ranging from once a day to once a month. For important pipelines or when water quality and hydraulic conditions fluctuate greatly, online continuous monitoring can be set to obtain electrochemical index system data in the time dimension.

[0120] The pipeline testing method provided in this application has the following advantages:

[0121] 1. Electrochemical methods are highly sensitive, real-time, and effective methods for testing the corrosion process and stability of metal pipe scale. In this application, the method is introduced into the monitoring of the inside of water supply pipelines, which can effectively reflect the corrosion rate and scale stability of iron pipe scale inside the water supply pipelines.

[0122] 2. This study optimized the electrochemical testing methods and parameters for the characteristic iron scale system on the inner walls of water supply networks. For example, a segmented measurement method for AC impedance spectroscopy was adopted. This method effectively ensures the fitting and calculation accuracy of the characterization method while controlling the total testing time, thus improving data accuracy and efficiency. Experimental results confirm that, while ensuring the convergence of the fitting results, the testing time for a single group can be controlled within 30 minutes.

[0123] 3. A new comprehensive electrochemical index system for corrosion and scale stability in water supply pipelines is proposed. This system can comprehensively assess pipeline corrosion and scale stability from multiple dimensions, including dynamic reaction processes and the inherent stability of scale, demonstrating both comprehensiveness and effectiveness. Simultaneously, a periodic electrochemical monitoring method for water supply networks is proposed, enabling continuous dynamic monitoring of pipeline corrosion and scale stability, obtaining a continuous dataset of electrochemical indicators, and facilitating relevant analyses.

[0124] 4. Excellent response speed and efficiency. Experiments have confirmed a strong linear correlation between changes in typical water quality factors (such as chloride ions and sulfate ions) and the selected electrochemical indicators. Therefore, electrochemical indicators can be effectively used to characterize the stability of pipe scale. Furthermore, electrochemical indicators can achieve instantaneous response to changes in water quality and flow rate.

[0125] In this embodiment, to obtain a set of electrochemical indicators that can comprehensively evaluate the properties of pipe scale and pipeline corrosion, a set of electrochemical testing methods based on polarization curve testing, AC impedance spectroscopy testing, and Mott-Schottky curve testing were designed. This embodiment specifies specific testing parameters and optimizes the AC impedance spectroscopy testing method, proposing a segmented AC impedance spectroscopy testing method. In this embodiment, electrochemical testing needs to be performed periodically on the pipeline electrode group to obtain continuous, periodic electrochemical signals of pipe scale and pipeline. The electrochemical testing consists of performing polarization curve testing, segmented AC impedance spectroscopy testing, and Mott-Schottky curve testing once each.

[0126] In this embodiment, based on the fundamental properties of iron-based pipes containing scale, specific test parameters are specified for the polarization curve method. The polarization curve test yields the corrosion voltage E, which represents the corrosion tendency and rate of the pipe's inner wall. corr and corrosion current I corr The testing methods and parameters used in AC impedance spectroscopy are highly correlated with the structure and impedance characteristics of the material under test, and the selection and values ​​of electrochemical parameters directly depend on the equivalent circuit used to fit the impedance data. In the embodiments of this application, a method is proposed for ferrous metal electrodes with minimal scale development. Figure 5 The equivalent circuit shown is the second equivalent circuit. This equivalent circuit model is a circuit model with two time constants, including the solution resistance R. s Scale film resistance R f Pipe scale membrane capacitor constant phase angle element CPE f Charge transfer resistance R ct and double-layer capacitor constant phase angle element CPE dl CPE f and CPE dl The capacitance C of the scale film can be analyzed separately. f and double-layer capacitance C dl .

[0127] However, once a well-developed and structurally stable scale forms on the inner wall of a water supply pipe, the scale exhibits extremely high impedance, particularly the charge transfer resistance R, which is highly correlated with the electrochemical process. ct It can reach 10 3 -10 9Ω / cm 2 Therefore, in AC impedance spectroscopy testing, compared to bare metal electrodes with lower impedance, standard spectral shape, and complete spectra, and electrodes containing low-impedance scale, electrodes with well-developed and dense scale layers exhibit higher impedance and greater spectral distortion, resulting in a larger fitting error. Specifically, using methods such as... Figure 5 The equivalent circuit shown yields a negative solution resistance at high frequencies; however, reducing the fitting error in the low-frequency region requires lowering the lower limit of the AC test frequency, which significantly increases the test time. Therefore, this application proposes a segmented measurement method, which involves determining the low-impedance and high-impedance properties of scale and conducting different supplementary tests for low-impedance and high-impedance scale, while fitting different equivalent circuit models. This improves the accuracy of AC impedance spectrum fitting while minimizing test time.

[0128] For low-impedance pipe scale, the core approach is to increase the test frequency at low-frequency points. For high-impedance pipe scale, the core approach is to lower the lower limit of the test frequency at low-frequency points, while also... Figure 5 The equivalent circuit model in the model is further adjusted, and the charge transfer resistor R is adjusted. ct Considered an open circuit, Figure 7 The equivalent circuit model in the diagram. By performing segmented AC impedance spectroscopy, the structural characteristics of scale on the inner wall of the pipe can be obtained, including high-resistance or low-resistance scale (two variables) and the scale film resistance R. f , Pipe scale membrane capacitance C f Charge transfer resistance R ct Double-layer capacitance C dl information.

[0129] The equivalent circuit fitting variance of the segmented AC impedance testing method can be reduced to 2%-10% of that of conventional single-measurement methods, and the testing time for a single AC impedance spectrum is controlled within 25 minutes, greatly optimizing the effectiveness of the AC impedance spectrum method. Therefore, in summary, this application's embodiments design a method for determining high and low impedance scale in ferrous pipes, and segmented AC impedance testing and combined fitting methods designed separately for high and low impedance scale.

[0130] The results of Mott-Schottky curve measurements are highly correlated with factors such as the test frequency. In this embodiment, the 10kHz system, which has the best testing effect on iron oxide pipe scale systems, was selected for electrochemical testing. The acceptor charge density N, which reflects the semiconductor properties of pipe scale on the inner wall of the pipe, can be obtained through Mott-Schottky curve testing. A Or donor electron density N D index.

[0131] Using the electrochemical testing methods based on polarization curve testing, AC impedance spectroscopy testing, and Mott-Schottky curve testing described above, this application presents an index system designed to evaluate the corrosion tendency and scale stability of the inner wall of water supply pipelines. This system can reflect corrosion reaction characteristics, scale structural characteristics, and scale semiconductor characteristics. The index system includes the corrosion voltage E, which reflects the corrosion reaction characteristics. corr Corrosion current I corr High-resistivity or low-resistivity scale (binary variable), scale film resistance R f , Pipe scale membrane capacitance C f Charge transfer resistance R ct Double-layer capacitance C dl and acceptor charge density N A Or donor electron density N D Electrochemical indicators are also considered. However, none of these single indicators can comprehensively evaluate the stability of scale in actual water supply pipelines, and the indicators are affected differently by different water qualities and hydraulic factors. Therefore, this application proposes a series of indicator evaluation systems that can comprehensively assess pipeline corrosion and scale stability from multiple dimensions, including dynamic reaction processes and the stability of the scale itself, demonstrating comprehensiveness and effectiveness.

[0132] Corresponding to the above-described pipeline condition testing method, this application embodiment also provides a pipeline condition testing device. Figure 9 This is a schematic diagram of the structure of a pipeline condition testing device provided in an embodiment of this application, as shown below. Figure 9 As shown, the testing apparatus for pipeline conditions includes:

[0133] The impedance type determination unit 600 is used to perform AC impedance spectroscopy testing on the working electrode placed inside the pipe under test according to different scanning parameters, so as to determine the impedance type of the scale in the pipe under test; wherein, the working electrode is made of pipe material cut from the pipe under test and the scale inside it, or is made of the same metal material as the pipe under test.

[0134] The test data acquisition unit 610 is used to perform AC impedance spectroscopy testing on the working electrode again using scanning parameters adapted to the impedance type of the scale in the pipe under test, and to fit the test results using an appropriate equivalent circuit to obtain scale characteristic test data.

[0135] In one exemplary instance, the scanning parameters include: scanning frequency range, scanning mode, and scanning amplitude. The impedance type determination unit 600 is used for:

[0136] The working electrode is scanned at each frequency using a first scanning frequency range, a first scanning mode, and a first scanning amplitude to obtain a first Nyquist plot; wherein, the first scanning frequency range includes a frequency range from a first frequency to a second frequency, and the first frequency is less than the second frequency;

[0137] The working electrode is scanned at each frequency using a second scanning frequency range, a second scanning mode, and a second scanning amplitude to obtain a second Nyquist plot; wherein, the second scanning frequency range includes a frequency scanning range determined from a third frequency to a first frequency, wherein the third frequency is less than the first frequency; the density of the scanning points selected in the first scanning mode is greater than the density of the scanning points selected in the second scanning mode;

[0138] The first Nyquist plot and the second Nyquist plot are merged to obtain the third Nyquist plot, and the frequency within the first frequency interval that minimizes the imaginary part of the third Nyquist plot is obtained as the target frequency; wherein, the first frequency interval is the frequency interval of the third Nyquist plot.

[0139] The third Nyquist plot within the second frequency range is fitted to the first equivalent circuit, and the preliminary double-layer capacitor constant phase angle element CPE′ is obtained through iterative calculation. dl and initial charge transfer resistance R′ ct ;

[0140] Based on the calculated preliminary double-layer capacitor constant phase angle element CPE′ dl and initial charge transfer resistance R′ ct Determine the impedance type of scale in the pipe under test;

[0141] The second frequency range is the frequency range including the target frequency to the third frequency; the first equivalent circuit is the preliminary scale film resistor R. f ′ and initial charge transfer resistance R′ ct Series connection, and initial charge transfer resistance R′ ct With the initial electric double-layer capacitor constant phase angle element CPE′ dl The equivalent circuit obtained by parallel connection.

[0142] In one exemplary instance, the initial double-layer capacitor constant phase angle element CPE′ dl Includes: preliminary double-layer capacitance C′ dl The power term α′ of the initial double-layer constant phase angle element dl The impedance type of scale in the pipe under test includes a first impedance type and a second impedance type, and the impedance of the first impedance type is lower than that of the second impedance type; the impedance type determination unit 600 is used for:

[0143] Calculate separately and Where i is the imaginary unit, and ω is the angular frequency obtained from the target frequency;

[0144] exist In this case, the impedance type of the scale in the pipe under test is determined to be the first impedance type;

[0145] exist In this case, the impedance type of the scale in the pipe under test is determined to be the second impedance type.

[0146] In one exemplary instance, the test data acquisition unit 610 is used for:

[0147] If the pipe scale is determined to be of the first impedance type, a fourth Nyquist plot is obtained by scanning at each frequency using the second scanning frequency range, the third scanning mode, and the third scanning amplitude; wherein, the density of the scanning points selected in the third scanning mode is greater than the density of the scanning points selected in the second scanning mode.

[0148] By merging the first and fourth Nyquist plots, we obtain the fifth Nyquist plot;

[0149] The fifth Nyquist plot was fitted to the second equivalent circuit, and the scale film resistance R was obtained through iterative calculation. f , Pipe scale membrane capacitance C f Charge transfer resistance R ct and double-layer capacitance C dl ;

[0150] The second equivalent circuit is the solution resistance R. s , pipe scale film resistance R f Charge transfer resistance R ct They are connected in series, and the charge transfer resistance R ct With double-layer capacitors, constant phase angle element CPE dl Parallel connection, and the scale film capacitor is a constant phase angle element CPE. f With the resistance R of the scale film f and charge transfer resistance R ct Equivalent circuit in parallel.

[0151] In one exemplary instance, the test data acquisition unit 610 is used for:

[0152] If the pipe scale is determined to be of the second impedance type, a sixth Nyquist plot is obtained by scanning at each frequency with a third scanning frequency range, a fourth scanning rate, and a fourth scanning amplitude; wherein, the third scanning frequency range includes the frequency range from the fourth frequency to the first frequency;

[0153] By merging the first Nyquist plot, the second Nyquist plot, and the sixth Nyquist plot, we obtain the seventh Nyquist plot;

[0154] The sixth Nyquist plot was fitted to the third equivalent circuit, and the scale film resistance R was obtained through iterative calculation. f , Pipe scale membrane capacitance C f Charge transfer resistance R ct and double-layer capacitance C dl ;

[0155] The third equivalent circuit is the solution resistance R. s , pipe scale film resistance R f Double-layer capacitor constant phase angle element CPE dl The components CPE are connected in series and are constant phase angle elements of the scale film capacitor. f With the resistance R of the scale film f Double-layer capacitor constant phase angle element CPE dl Equivalent circuit in parallel.

[0156] In one exemplary instance, the first frequency is 1000Hz, and the second frequency is 5×10⁻⁶. 5 The first scan mode is 10 points / 10 times the frequency, the second scan mode is 2 points / 10 times the frequency, and the third scan mode is 10 points / 10 times the frequency. The amplitudes of the first scan, the second scan, and the third scan are all 10mV.

[0157] In one exemplary instance, the fourth frequency is 0.001 Hz and the fourth scan amplitude is 10 mV.

[0158] In one exemplary instance, the test data acquisition unit 610 is further configured to:

[0159] Polarization curves are measured using a working electrode placed inside the pipe under test to obtain the corrosion voltage E, which represents the corrosion status of the pipe's inner wall. corr and corrosion current I corr ;

[0160] In the polarization curve test, the initial voltage is 0.5V lower than the open-circuit voltage and the termination voltage is 0.5V higher than the open-circuit voltage within the scanning range, with a voltage interval of 10mV / s.

[0161] In one exemplary instance, the test data acquisition unit 610 is further configured to:

[0162] MS curve testing was performed on the working electrode placed inside the test pipe to obtain the donor charge density N. D Or subject to the main electron density N A ;

[0163] Among them, when the slope of the applied voltage in the MS curve is positive, the donor charge density N is obtained. D When the slope of the applied voltage is negative, the acceptor electron density N is obtained. A In the MS curve test, the initial voltage is 0.7V lower than the open circuit voltage, the termination voltage is 0.3V lower than the open circuit voltage, the voltage frequency is 10kHz, and the voltage step is 0.04V.

[0164] The pipeline condition testing device provided in this embodiment belongs to the same concept as the pipeline condition testing method provided in the above embodiments of this application. It can execute the pipeline condition testing method provided in any of the above embodiments of this application and has the corresponding functional modules and beneficial effects for executing the pipeline condition testing method. Technical details not described in detail in this embodiment can be found in the specific processing content of the pipeline condition testing method provided in the above embodiments of this application, and will not be repeated here.

[0165] This application also provides an electronic device, such as... Figure 10 As shown, it includes: a memory 700 and a processor 710;

[0166] The memory 700 is connected to the processor 710 and is used to store programs;

[0167] The processor 710 is used to implement the test method for the pipeline conditions described in any of the above embodiments by running the program in the memory 700.

[0168] Specifically, the aforementioned electronic device may also include: a bus, a communication interface 720, an input device 730, and an output device 740.

[0169] The processor 710, memory 700, communication interface 720, input device 730, and output device 740 are interconnected via a bus. Among them:

[0170] A bus can include a pathway for transmitting information between various components of a computer system.

[0171] The processor 710 can be a general-purpose processor, such as a general-purpose central processing unit (CPU), a microprocessor, etc., or an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the program of the present invention. It can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0172] The processor 710 may include a main processor, as well as a baseband chip, modem, etc.

[0173] The memory 700 stores a program that executes the technical solution of this invention, and may also store an operating system and other key business functions. Specifically, the program may include program code, which includes computer operation instructions. More specifically, the memory 700 may include read-only memory (ROM), other types of static storage devices capable of storing static information and instructions, random access memory (RAM), other types of dynamic storage devices capable of storing information and instructions, disk storage, flash memory, etc.

[0174] Input device 730 may include a device for receiving data and information input by a user, such as a keyboard, mouse, camera, scanner, light pen, voice input device, touch screen, pedometer, or gravity sensor.

[0175] Output device 740 may include devices that allow information to be output to a user, such as a display screen, printer, speaker, etc.

[0176] The communication interface 720 may include a device that uses any transceiver to communicate with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), Wireless Local Area Network (WLAN), etc.

[0177] The processor 710 executes the program stored in the memory 700 and calls other devices, which can be used to implement the various steps of the test method for any pipeline condition provided in the above embodiments of this application.

[0178] In addition to the methods and apparatus described above, embodiments of this application may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps in the test methods for pipeline scenarios according to various embodiments of this application as described in any of the foregoing embodiments of this specification.

[0179] Computer program products can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0180] Furthermore, this application also provides a storage medium storing a computer program, which, when run by a processor, implements the testing method for pipeline conditions described in any of the above embodiments.

[0181] It will be understood by those skilled in the art that all or some of the steps, systems, or apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term "computer storage medium" includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

Claims

1. A method for testing pipeline conditions, characterized in that, include: AC impedance spectroscopy is performed on the working electrode placed inside the pipe under test according to different scanning parameters to determine the impedance type of the scale in the pipe under test; wherein, the working electrode is made of pipe material cut from the pipe under test and the scale inside it, or is made of the same metal material as the pipe under test. The working electrode is subjected to AC impedance spectroscopy again using scanning parameters that are compatible with the impedance type of the scale in the pipe under test. The test results are then fitted with an equivalent circuit to obtain scale characteristic test data. The scanning parameters include: scanning frequency range, scanning mode, and scanning amplitude. The step of performing AC impedance spectroscopy on the working electrode placed inside the pipe under test according to different scanning parameters to determine the impedance type of the scale in the pipe under test includes: The working electrode is scanned at each frequency using a first scanning frequency range, a first scanning mode, and a first scanning amplitude to obtain a first Nyquist plot; wherein, the first scanning frequency range includes a frequency range from a first frequency to a second frequency, and the first frequency is less than the second frequency; The working electrode is scanned at each frequency using a second scanning frequency range, a second scanning mode, and a second scanning amplitude to obtain a second Nyquist plot; wherein, the second scanning frequency range includes a frequency range from a third frequency to a first frequency, and the third frequency is less than the first frequency; the density of the scanning points selected in the first scanning mode is greater than the density of the scanning points selected in the second scanning mode. The first Nyquist plot and the second Nyquist plot are merged to obtain the third Nyquist plot, and the frequency within the first frequency interval that minimizes the imaginary part of the third Nyquist plot is obtained as the target frequency; wherein, the first frequency interval is the frequency interval of the third Nyquist plot. The third Nyquist plot within the second frequency range is fitted to the first equivalent circuit, and the preliminary double-layer capacitor constant phase angle element is obtained through iterative calculation. and initial charge transfer resistance ; Based on the calculated preliminary phase angle elements of the double-layer capacitor and initial charge transfer resistance The impedance type of the scale in the pipe under test is determined; The second frequency range includes the frequency range from the target frequency to the third frequency; the first equivalent circuit is a preliminary pipe scale film resistor. With initial charge transfer resistance Series connection, and initial charge transfer resistance With initial double-layer capacitor constant phase angle element The equivalent circuit obtained by parallel connection; The initial double-layer capacitor constant phase angle element Includes: preliminary electric double-layer capacitance The power term of the initial double-layer constant phase angle element The impedance type of the scale in the pipe to be tested includes a first impedance type and a second impedance type, and the impedance of the first impedance type is lower than the impedance of the second impedance type. The preliminary double-layer capacitor constant phase angle element obtained from the calculation and initial charge transfer resistance Determining the impedance type of scale in the pipe under test includes: Calculate separately and ;in, The imaginary unit, The angular frequency is obtained based on the target frequency; exist In this case, the impedance type of the scale in the pipe under test is determined to be the first impedance type; exist In this case, the impedance type of the scale in the pipe under test is determined to be the second impedance type; The working electrode is subjected to AC impedance spectroscopy again using scanning parameters adapted to the impedance type of the scale in the pipe under test, and the test results are fitted using an appropriate equivalent circuit to obtain scale characteristic test data, including: If the pipe scale is determined to be of the first impedance type, a fourth Nyquist plot is obtained by scanning at each frequency using a second scanning frequency range, a third scanning mode, and a third scanning amplitude; wherein the density of the scanning points selected in the third scanning mode is greater than the density of the scanning points selected in the second scanning mode. The first Nyquist plot and the fourth Nyquist plot are combined to obtain the fifth Nyquist plot; The fifth Nyquist plot is fitted to the second equivalent circuit, and the scale film resistance is obtained through iterative calculation. R f Pipe scale membrane capacitor C f Charge transfer resistance R ct and double-layer capacitor C dl ; The second equivalent circuit is a solution resistor. R s Pipe scale membrane resistance R f Charge transfer resistance R ct Series connected in sequence, and charge transfer resistance With double-layer capacitors and constant phase angle elements CPE dl Parallel connection, and the scale film capacitor is a constant phase angle element. CPE f With pipe scale film resistance R f Charge transfer resistance R ct Equivalent circuit in parallel.

2. The method according to claim 1, characterized in that, The working electrode is subjected to AC impedance spectroscopy again using scanning parameters adapted to the impedance type of the scale in the pipe under test, and the test results are fitted using an appropriate equivalent circuit to obtain scale characteristic test data, including: If the pipe scale is determined to be of the second impedance type, a sixth Nyquist plot is obtained by scanning at each frequency using a third scanning frequency range, a fourth scanning mode, and a fourth scanning amplitude; wherein, the third scanning frequency range includes the frequency range from the fourth frequency to the first frequency; The first Nyquist plot, the second Nyquist plot, and the sixth Nyquist plot are merged to obtain the seventh Nyquist plot; The sixth Nyquist plot is fitted to the third equivalent circuit, and the scale film resistance is obtained through iterative calculation. R f Pipe scale membrane capacitor C f Charge transfer resistance R ct and double-layer capacitor C dl ; The third equivalent circuit is a solution resistor. R s Pipe scale membrane resistance R f Double-layer capacitors with constant phase angle elements CPE dl Series-connected, and the scale film capacitor is a constant phase angle element. CPE f With pipe scale film resistance R f Double-layer capacitors with constant phase angle elements CPE dl Equivalent circuit in parallel.

3. The method according to claim 1, characterized in that, The first frequency is 1000 Hz, the second frequency is 5 x 10 5 Hz, the third frequency is 0.01 Hz, the first scanning mode is 10 points / 10 times frequency, the second scanning mode is 2 points / 10 times frequency, the third scanning mode is 10 points / 10 times frequency, and the first scanning amplitude, the second scanning amplitude, and the third scanning amplitude are all 10 mV.

4. The method according to claim 2, characterized in that, The fourth frequency is 0.001 Hz, and the fourth scanning amplitude is 10 mV.

5. The method according to claim 1, characterized in that, The method further includes: A polarization curve test was performed on the working electrode placed inside the pipe under test to obtain the corrosion voltage, which represents the corrosion status of the pipe's inner wall. E corr and corrosion current I corr ; In the polarization curve test, the initial voltage is 0.5 V lower than the open-circuit voltage, the termination voltage is 0.5 V higher than the open-circuit voltage, and the voltage interval is 10 mV / s.

6. The method according to claim 1, characterized in that, The method further includes: MS curve testing was performed on the working electrode placed inside the test pipe to obtain the donor charge density. N D Or subject to the density of the main electron N A ; Among them, when the slope of the applied voltage in the MS curve is positive, the donor charge density is obtained. N D When the slope of the applied voltage is negative, the acceptor electron density is obtained. N A In the MS curve test, the initial voltage is 0.7 V lower than the open circuit voltage, the termination voltage is 0.3 V lower than the open circuit voltage, the voltage frequency is 10 kHz, and the voltage step is 0.04 V.

7. An electronic device, characterized in that, include: Memory and processor; The memory is connected to the processor and is used to store programs; The processor is configured to implement the pipeline condition testing method as described in any one of claims 1-6 by running a program in the memory.

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