Method, system, device and medium for predicting remaining life of co2 pipeline

Abstract

This application discloses a method, system, device, and medium for predicting the remaining life of CO2 pipelines, applied in the field of carbon capture and storage technology. The method includes: acquiring electrochemical impedance spectroscopy (EIS) data of corrosion product films on the inner wall of the CO2 pipeline, collected by an electrochemical sensor array embedded in the pipeline; based on the EIS data, using a multilayer equivalent circuit model matching the layered structure of the corrosion product film, inverting the resistance values ​​of each layer of the corrosion product film; and based on the resistance values ​​of each layer, predicting the remaining life of the CO2 pipeline. This application achieves refined quantitative characterization of the layered structure of the corrosion product film, improving the accuracy and reliability of CO2 pipeline remaining life prediction.

Description

Technical Field

[0001] This application relates to the field of carbon capture and storage technology, and in particular to a method, system, equipment and medium for predicting the remaining life of CO2 pipelines. Background Technology

[0002] In carbon capture and storage (CCS) technology, a corrosion product film (mainly FeCO3 film) forms on the inner wall of carbon dioxide (CO2) pipelines due to CO2 corrosion.

[0003] Currently, the commonly used method for predicting the remaining life of CO2 pipelines is to use the linear polarization resistance method (LPR) to obtain the average metal corrosion rate and then predict the remaining life of the CO2 pipeline based on the average metal corrosion rate. This method tends to be optimistic in predicting the remaining life of CO2 pipelines, resulting in low prediction accuracy and a high false positive rate. Summary of the Invention

[0004] This application provides a method, system, equipment, and medium for predicting the remaining life of CO2 pipelines, aiming to address the problem of poor emergency evacuation effectiveness in the event of CO2 leaks. The technical solution provided by this application is as follows: On the one hand, this application provides a method for predicting the remaining life of CO2 pipelines, including: Electrochemical impedance spectroscopy (EIS) data of corrosion product films on the inner wall of CO2 pipelines were acquired by an electrochemical sensor array embedded in the inner wall of the CO2 pipeline. Based on electrochemical impedance spectroscopy data, a multilayer equivalent circuit model matching the layered structure of the corrosion product film is used to invert the resistance value of each layer of the corrosion product film. The remaining life of the CO2 pipeline is estimated based on the resistance values ​​of each layer of the corrosion product film.

[0005] The above scheme combines electrochemical impedance spectroscopy data with a multilayer equivalent circuit model that matches the layered structure to obtain the independent resistance values ​​of each layer. This breaks through the limitations of traditional overall impedance measurement and enables precise positioning of the main control mechanism of the corrosion process and accurate prediction of the remaining lifetime.

[0006] Optionally, after acquiring the electrochemical impedance spectroscopy data of the corrosion product film on the inner wall of the CO2 pipeline collected by the electrochemical sensor array embedded in the inner wall of the CO2 pipeline, the method further includes: Based on electrochemical impedance spectroscopy data, the various layers of the corrosion product film were identified; Based on the various layers of the corrosion product film, a multilayer equivalent circuit model is constructed.

[0007] The above scheme ensures a strict correspondence between the multi-layer equivalent circuit model and the actual physical layer structure by first identifying the layers and then constructing the model, thereby improving the physical meaning and accuracy of the model inversion parameters.

[0008] Optionally, based on electrochemical impedance spectroscopy data, the various layers of the corrosion product film are identified, including: The relaxation time distribution was used to decompose the electrochemical impedance spectroscopy data to obtain the peaks of each time constant; Based on the correspondence between the time constant peak range and the various layers of the corrosion product film, the layer to which each time constant peak belongs is identified.

[0009] The above scheme directly decomposes electrochemical impedance spectroscopy data into independent time constant peaks through relaxation time distribution technology. It can automatically identify the electrochemical response characteristics of each film layer without the need for a preset equivalent circuit structure, thus avoiding subjective errors caused by human-preset models.

[0010] Optionally, the layered structure of the corrosion product film includes: an outer porous layer, an inner dense layer, and a substrate film interface; Based on the various layers of the corrosion product film, a multilayer equivalent circuit model is constructed, including: Construct a first equivalent circuit for the outer porous film layer, which is formed by the first resistor and the first capacitor connected in parallel. Construct a second equivalent circuit for the inner dense film layer, which is formed by the second resistor and the second capacitor connected in parallel. A third equivalent circuit is constructed for the substrate membrane interface, consisting of a third resistor and a third capacitor connected in parallel. The first, second, and third equivalent circuits are connected in series, and then connected in series with the corrosive solution resistor to form a multilayer equivalent circuit model.

[0011] The above scheme fully reproduces the barrier and polarization response mechanism of the layered structure to electrochemical current by constructing parallel equivalent circuits and series solution resistances for the outer loose layer, inner dense layer and substrate film interface, respectively, laying the circuit topology foundation for accurate inversion of the resistance of each layer.

[0012] Optionally, the layered structure of the corrosion product film includes: an outer porous layer, an inner dense layer, and a substrate film interface; Based on electrochemical impedance spectroscopy data, a multilayer equivalent circuit model matching the layered structure of the corrosion product film was used to invert the resistance values ​​of each layer of the corrosion product film, including: Based on electrochemical impedance spectroscopy data, a multilayer equivalent circuit model was used, and the first resistance value of the outer porous layer, the second resistance value of the inner dense layer, and the third resistance value of the substrate membrane interface were calculated by complex nonlinear least squares fitting.

[0013] The above scheme uses a complex nonlinear least squares fitting algorithm to solve the parameters of the multilayer equivalent circuit model, ensuring a high degree of consistency between the first, second, and third resistors obtained by inversion within the range of mathematical optimal solution and physical constraints.

[0014] Optionally, the resistance values ​​of each layer include: a first resistance value of the outer porous layer, a second resistance value of the inner dense layer, and a third resistance value of the matrix film interface; Based on the resistance values ​​of each layer of the corrosion product film, the remaining life of the CO2 pipeline is estimated, including: If the second resistance value is greater than the third resistance value, which is greater than the first resistance value, then the remaining time required for the second resistance value to drop to the preset failure threshold is calculated based on the time decay function of the second resistance value, and this time is taken as the initial remaining life of the CO2 pipeline. If the third resistance value is greater than the second resistance value, which is greater than the first resistance value, then the current corrosion rate of the substrate film interface is calculated based on the third resistance value. Based on the current corrosion rate, the remaining life of the substrate film interface is calculated according to the uniform corrosion model as the initial remaining life of the CO2 pipeline. If the first resistance value is greater than the second resistance value, which is greater than the third resistance value, then the remaining time required for the second resistance value to decrease to the preset failure threshold is calculated based on the time decay function of the second resistance value. The current corrosion rate of the substrate film interface is calculated based on the third resistance value. Based on the current corrosion rate, the remaining lifetime of the substrate film interface is calculated according to the uniform corrosion model. The remaining time and remaining lifetime are weighted according to the second and third resistance values ​​to obtain the initial remaining lifetime of the CO2 pipeline.

[0015] The above scheme dynamically determines the main corrosion control step or transition state by comparing the magnitude of the first, second, and third resistances. When the first resistance is greater than the second resistance, which is greater than the third resistance, a weighted fusion model is used to dynamically weight the inner film decay time scale and the interface corrosion thinning lifetime scale. The lifetime is corrected based on the sudden drop in the first resistance. This achieves full-scenario coverage of inner film control, interface control, multi-mechanism parallel competition transition state, and film peeling correction, avoiding misjudgments caused by a single model.

[0016] Optionally, after estimating the remaining life of the CO2 pipeline based on the resistance values ​​of each layer of the corrosion product film, the process also includes: When the remaining lifespan of the CO2 pipeline is below the safety threshold, a warning signal is output.

[0017] The above solution sets safety thresholds and outputs early warning signals, enabling the prediction results to be directly converted into engineering decision-making instructions, effectively avoiding sudden failure accidents.

[0018] On the other hand, this application provides a CO2 pipeline remaining life prediction system, comprising: The data acquisition unit is used to acquire electrochemical impedance spectroscopy data of the corrosion product film on the inner wall of the CO2 pipeline collected by the electrochemical sensor array embedded in the inner wall of the CO2 pipeline. The contribution inverse unit is used to inversely calculate the resistance value of each layer of the corrosion product film based on electrochemical impedance spectroscopy data and using a multilayer equivalent circuit model that matches the layered structure of the corrosion product film. The lifespan prediction unit is used to predict the remaining lifespan of a CO2 pipeline based on the resistance values ​​of each layer of the corrosion product film.

[0019] On the other hand, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method for predicting the remaining life of a CO2 pipeline.

[0020] On the other hand, this application also provides a computer-readable storage medium storing computer instructions, which, when executed by a processor, implement the above-described method for predicting the remaining life of a CO2 pipeline.

[0021] The beneficial effects of this application are as follows: 1. This application uses a multilayer equivalent circuit model that matches the layered structure of the corrosion product film to invert electrochemical impedance spectroscopy data, obtains the independent resistance values ​​of each layer at the interface of the outer loose layer, the inner dense layer and the substrate film, decouples the originally mixed overall impedance, overcomes the defect of traditional methods that cannot distinguish the influence of film structure changes on the corrosion process, realizes a refined quantitative characterization of the corrosion evolution mechanism, and thus significantly improves the accuracy of remaining lifetime prediction.

[0022] 2. This application dynamically determines whether the corrosion rate is controlled by the inner dense film or by the substrate / film interface by comparing the relative magnitudes of the second and third resistances. Based on this, the corresponding decay function or uniform corrosion model is selected to calculate the initial remaining lifetime. This conforms to the objective law of the dynamic evolution of the corrosion process from film protection to interface failure, avoids misjudgment by a single model under inapplicable working conditions, and improves the reliability of the prediction results.

[0023] 3. By monitoring the decrease in the first resistance, this application multiplies the initial remaining lifetime by a correction factor when the outer porous film partially peels off, thereby capturing the accelerated local corrosion effect caused by the peeling off of the outer film. This reveals the catalytic effect of the failure of the porous layer on the overall protective damage, achieving early warning of local corrosion risk and lifetime reduction, and effectively preventing sudden failure hazards.

[0024] 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. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the general flow of the CO2 pipeline remaining life prediction method in the embodiments of this application; Figure 2 This is a schematic diagram of the composition of the CO2 pipeline remaining life prediction system in an embodiment of this application; Figure 3 This is a schematic diagram of the hardware structure of the electronic device in the embodiments of this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and beneficial effects of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] CO2 corrosion causes the formation of a layered corrosion product film (primarily FeCO3 film) on the inner wall of CO2 pipelines. Numerous studies have shown that, even with a fully formed protective film on the inner wall, the layered structure of this corrosion product film includes an outer porous layer, an inner dense layer, and a substrate film interface. Accurately assessing the stability and protective performance of this layered corrosion product film is a crucial prerequisite for predicting the remaining life of CO2 pipelines.

[0028] Currently, traditional electrochemical methods for monitoring CO2 pipeline corrosion, such as the linear polarized resistance method (LPR), treat the corrosion product film as a single, uniform barrier layer to obtain average information on the metal corrosion rate. This traditional method cannot distinguish the contribution of the barrier layer to the corrosion rate process, nor can it capture changes in the diffusion path caused by localized peeling of the outer film. The direct consequence is that when the inner dense film is damaged but the outer film is still partially present, the overall impedance may still appear high, leading to a severely overly optimistic prediction of the remaining life of the CO2 pipeline, increasing the risk of sudden failure, and resulting in low prediction accuracy and a high false alarm rate.

[0029] Therefore, this application provides a method for quantitatively characterizing the electrochemical features of corrosion product film layering and for achieving high-precision prediction of the remaining life of CO2 pipelines based on the evolution law of layered structure. For details, please refer to... Figure 1 As shown in the embodiments of this application, the general flow of the CO2 pipeline remaining life prediction method is as follows: Step 101: Obtain electrochemical impedance spectroscopy data of corrosion product films on the inner wall of CO2 pipelines, collected by an electrochemical sensor array embedded in the inner wall of the CO2 pipeline.

[0030] In this embodiment, in the CO2 pipeline of the carbon capture and storage project, the inner wall of the pipeline is exposed to a corrosive aqueous medium containing CO2 for a long time, inevitably generating a corrosion product film with a complex layered structure. To capture the electrochemical response characteristics of these films in real time, an electrochemical sensor array needs to be deployed at various key corrosion monitoring points on the inner wall of the pipeline. Each key corrosion monitoring point employs an embedded installation flush with the inner wall surface of the CO2 pipeline. Installation locations: During pipeline manufacturing or modification, mounting holes or grooves are pre-set on the pipe wall at key locations such as the outside of elbows, downstream of diameter changes, and the heat-affected zone of welds. Installation method: The sensor array (working electrode, reference electrode, auxiliary electrode) is encapsulated in a pressure-resistant and insulated base. The working surface (electrode surface) of the sensor is conformal to and flush with the curved surface of the inner wall of the pipeline (the surface height difference is controlled within ±0.1 mm). Electrode leads are led out from the outside of the pipe wall and sealed, connecting to an external electrochemical workstation. By employing an embedded installation flush with the inner wall surface of the CO2 pipeline, flow field disturbances can be avoided, preventing the generation of eddies or scouring corrosion, and protection against damage from pigging or particles in the fluid. This ensures that the corrosive environment (flow field, temperature, pressure, CO2 partial pressure) of the sensor surface is consistent with that of the pipeline inner wall. By keeping the sensor's working surface (electrode surface) conformal and flush with the curved surface of the pipeline inner wall, the working electrode can contact the medium inside the pipe, enabling the acquisition of electrochemical impedance spectroscopy (EIS) data. Specifically, these sensors typically employ a three-electrode system. By applying a small-amplitude sinusoidal AC perturbation signal within a specific frequency range, the impedance response of the region on the pipeline inner wall covered with a corrosion product film at different frequencies is measured, thereby obtaining continuous EIS data.

[0031] It should be understood that although the embodiments of this application use a three-electrode sensor as an example, in other embodiments, a two-electrode system or other probe configurations suitable for monitoring the inner wall of a closed pipe can also be used, as long as they can stably output frequency domain data reflecting the impedance characteristics of the film layer.

[0032] Step 102: Based on electrochemical impedance spectroscopy data, a multilayer equivalent circuit model matching the layered structure of the corrosion product film is used to invert the resistance value of each layer of the corrosion product film.

[0033] Specifically, the core of this step lies in the physical connotation of "multi-layer equivalent circuit model" and "matching of layered structure". Traditional electrochemical impedance spectroscopy analysis often uses a single overall equivalent circuit model, such as treating the entire corrosion product film as a homogeneous barrier layer, only reflecting an overall polarization resistance. However, the corrosion product film on the inner wall of a CO2 pipeline is not a homogeneous whole in physical morphology, but rather exhibits a layered structure with multiple superimposed layers, including a loose outer layer, a dense inner layer, and a substrate film interface. If a single overall model is forcibly used to fit this layered system with multiple independent relaxation processes, it will not only lead to the fitting results getting mathematically trapped in a local optimum, but more seriously, it will physically obliterate the differentiated contribution of each film layer to the corrosion process. The ability of each film layer to hinder charge transfer is quite different; the dense inner layer may provide the main protective resistance, while the loose outer layer may provide almost no protection or even act as a channel for the corrosive medium to penetrate. Therefore, in this embodiment, a multi-layer equivalent circuit model that strictly matches the actual layered structure is adopted. This structure-matching modeling decouples the electrochemical responses of each layer, which were originally mixed in the overall impedance spectrum, and inversely calculates the independent resistance value of each layer. The purpose of this inversion process is to separate the protective contribution of each film layer from the overall confused signal, achieve refined quantitative characterization, and thus lay the physical foundation for subsequent precise localization of the main corrosion control mechanism.

[0034] Step 103: Estimate the remaining life of the CO2 pipeline based on the resistance values ​​of each layer of the corrosion product film.

[0035] Specifically, after obtaining the independent resistance values ​​of each layer, the remaining lifespan of the pipeline is no longer estimated based on the fuzzy overall corrosion rate. Instead, it is predicted directly based on the protective decay state of the membrane layer reflected by the resistance values ​​of each layer. Since the resistance values ​​of different membrane layers represent their ability to impede the penetration of corrosive media and charge transfer, the magnitude of the resistance value and its decay trend over time directly reflect the physical integrity and protective effectiveness of the membrane layer. By tracking these decoupled layer resistance values, it is possible to accurately identify which membrane layer is currently dominating the overall corrosion rate. Then, based on the resistance decay law or corrosion kinetic model of the dominant membrane layer, the remaining service time allowed from the current moment until the pipeline wall thickness thins to the failure threshold can be calculated. It should be understood that although this application only illustrates the basic logic of estimating lifespan based on layer resistance values, in specific engineering applications, the prediction model can adopt different functional forms or calculation paths depending on the dominant membrane layer. These specific advanced judgment logics will be further elaborated in subsequent embodiments. This application aims to establish the broadest possible framework for layered decoupling prediction.

[0036] The above scheme decouples the original mixed overall impedance from the root of the physical structure, overcomes the inherent defect of traditional methods that cannot distinguish the impact of changes in film structure on the corrosion process, and realizes a refined quantitative characterization of the corrosion evolution mechanism. This significantly improves the accuracy and reliability of remaining life prediction and provides solid technical support for the safe operation and maintenance of CO2 pipelines in CCS projects.

[0037] The following details the extraction of layered structures from electrochemical impedance spectroscopy (EIS) data and the construction of equivalent circuit models. Specifically, after acquiring EIS data of the inner wall of a CO2 pipeline collected by an array of electrochemical sensors installed on the inner wall, the process includes: identifying the layers of the corrosion product film on the inner wall of the CO2 pipeline based on the EIS data; and constructing a multilayer equivalent circuit model based on the layers of the corrosion product film.

[0038] Traditionally, a common approach to identifying hierarchical structures based on electrochemical impedance spectroscopy data is to manually predetermine an equivalent circuit topology and then obtain parameters through fitting. However, this subjective method of predetermining the equivalent circuit topology has significant drawbacks: operators often predetermine the number of parallel RC branches in the circuit based on personal experience or literature conventions. This subjective predetermination can easily lead to forcibly combining relaxation responses belonging to different physical processes into a single branch, or to omitting certain weak but crucial local response processes, thus causing subsequent inversion results to deviate from the true physical mechanism.

[0039] To overcome the limitations of this subjective presupposition, this application employs an objective technique for automatically constructing circuit structures. Specifically, based on electrochemical impedance spectroscopy data, the various layers of the corrosion product film on the inner wall of the CO2 pipeline are identified, including: decomposing the electrochemical impedance spectroscopy data using relaxation time distribution to obtain various time constant peaks; and identifying the layer to which each time constant peak belongs based on the correspondence between the time constant peak range and the various layers of the corrosion product film.

[0040] Among them, relaxation time distribution technology is a mathematical inversion tool that converts frequency domain impedance data into time domain distribution. It can objectively decompose the complex EIS spectrum, which is originally overlapping and mixed in the frequency domain, into a series of polarization process peaks with independent time constants. Each time constant peak represents an electrochemical physical process with a specific relaxation rate, automatically revealing the hidden independent kinetic steps in the system without requiring human guesswork about the circuit topology. In the context of the layered structure of the corrosion product film on the inner wall of a CO2 pipeline, there is a rigorous electrochemical physical mapping relationship between these time constant peaks and the layering.

[0041] Specifically, based on the correspondence between the time constant peak range and the various layers of the corrosion product film, the layer to which each time constant peak belongs is identified, following the physical logic: High-frequency time constant peaks, with extremely short relaxation times, correspond to the outer porous layer. This is because the outer porous film typically contains numerous pores and defects, allowing corrosive media ions to rapidly penetrate and migrate, resulting in an extremely rapid polarization response; therefore, its electrochemical relaxation process is concentrated in the high-frequency range. Mid-frequency time constant peaks, with moderate relaxation times, correspond to the inner dense layer. The inner dense film is the core barrier layer hindering the corrosion process; its structure is dense with very few defects, requiring ion penetration and charge transfer to overcome a high energy barrier, resulting in a moderate polarization response speed; therefore, its relaxation process exhibits characteristic peaks in the mid-frequency range. Low-frequency time constant peaks, with longer relaxation times, correspond to the substrate-film interface. At the interface between the substrate and the film, the final steps of metal dissolution and charge transfer are involved; the reaction kinetics are relatively slow, and the polarization response is the slowest, therefore, its relaxation process must fall in the low-frequency range. By using this objective mapping from frequency domain data to physical layers, the embodiments of this application completely eliminate the errors caused by subjectively preset circuits, ensuring a strict correspondence between the subsequently constructed multi-layer equivalent circuit model and the actual physical layer structure, and improving the physical meaning and accuracy of the model inversion parameters.

[0042] It should be understood that although the embodiments of this application focus on illustrating the correspondence between the three time constant peaks (high frequency, mid frequency, and low frequency) and the three main controlling layers (outer layer, inner layer, and substrate interface), in actual complex corrosion conditions, the number of peaks decomposed from the relaxation time distribution may be more than three. For example, when the presence of sublayer structures or local pitting corrosion within the dense inner film triggers additional micro-polarization processes, additional accompanying peaks may appear in specific frequency bands on the DRT spectrum. For these accompanying peaks, they can be merged into adjacent main controlling layers for refined characterization based on the frequency range of their time constants, or they can be treated as specific signals of local defects for specialized extraction. As long as the principle of matching the time constant peak range with the physical layer relaxation characteristics is met, it falls within the scope of the technical concept protected by this invention.

[0043] The following section elaborates on the specific topological construction of the multilayer equivalent circuit model and the algorithm for inverting and solving the model parameters. Specifically, the layered structure of the corrosion product film includes: an outer porous layer, an inner dense layer, and a substrate film interface. Based on each layer of the corrosion product film, a multilayer equivalent circuit model is constructed, including: constructing a first equivalent circuit for the outer porous film layer, formed by a first resistor and a first capacitor connected in parallel; constructing a second equivalent circuit for the inner dense film layer, formed by a second resistor and a second capacitor connected in parallel; constructing a third equivalent circuit for the substrate film interface, formed by a third resistor and a third capacitor connected in parallel; and connecting the first, second, and third equivalent circuits in series with the corrosive solution resistor to form the multilayer equivalent circuit model.

[0044] Specifically, this topology of three parallel-series solution resistors is a precise physical mapping of the electrochemical behavior of the complex corrosion system of the inner wall of a CO2 pipeline. In the layered structure of the corrosion product film, the outer porous film layer, the inner dense film layer, and the substrate film interface each constitute an independent polarization process with different relaxation times and impedance responses. Each equivalent circuit branch formed by parallel resistance and capacitance can precisely characterize the charge transfer resistance and double-layer charge-discharge characteristics of an independent polarization process. Specifically, the first resistance reflects the resistance encountered by the corrosive medium when penetrating the outer porous layer, and the first capacitance reflects the charge storage capacity of the outer porous film interface; the second resistance reflects the strong barrier effect of the inner dense film on the penetration of corrosive ions, and the second capacitance reflects the capacitance characteristics of the interface between the dense film and the substrate; the third resistance reflects the charge transfer resistance of the metal dissolution reaction at the substrate film interface, and the third capacitance reflects the charge-discharge response of the double layer on the substrate surface. The corrosive solution resistor connected in series at the beginning refers to the resistance exhibited by the corrosive solution (aqueous medium containing CO2) within the CO2 pipeline when current flows through it. It represents the ohmic resistance of the solution phase itself and is independent of the polarization process of the film or interface; therefore, it must be connected in series with the subsequent polarization branch in the circuit topology. It should be understood that although the embodiments of this application depict a standard topology with three parallel branches connected in series with a solution resistor, in actual operating conditions, if DRT decomposition identifies additional sublayers or local pitting corrosion features, those skilled in the art can connect additional RC branches in parallel or in series on this topological framework to adapt to more complex physical processes, as long as it does not violate the core concept of layered decoupling.

[0045] After constructing a multilayer equivalent circuit model that strictly matches the physical layering, accurately solving for the resistance parameters of each layer from the mixed frequency domain impedance spectroscopy data is the key to determining the prediction accuracy. In this embodiment, the layered structure of the corrosion product film includes: an outer porous layer, an inner dense layer, and a substrate film interface. Based on electrochemical impedance spectroscopy data, a multilayer equivalent circuit model matching the layered structure of the corrosion product film on the inner wall of the CO2 pipeline is used to invert the resistance values ​​of each layer of the corrosion product film. This includes: based on the electrochemical impedance spectroscopy data, using the multilayer equivalent circuit model, and through complex nonlinear least squares fitting, inverting and calculating the first resistance of the outer porous layer, the second resistance of the inner dense layer, and the third resistance of the substrate film interface.

[0046] Specifically, complex nonlinear least squares fitting (CNLS) is a mathematical algorithm that performs a globally optimal match between the measured impedance spectrum and the model-predicted impedance spectrum in the complex domain. Its core lies in constructing an objective function Φ to measure the deviation between the two. The mathematical structure of the objective function Φ is the sum of squared weighted residuals between the measured complex impedance at each frequency point and the model-predicted complex impedance. Mathematically, Φ equals the sum of the squares of the differences between the real parts of the measured impedance and the real parts of the model at all frequencies, plus the squares of the differences between the imaginary parts of the measured impedance and the imaginary parts of the model, multiplied by the weighting coefficients for the corresponding frequencies. The weighting coefficients are usually set as the reciprocal of the square of the magnitude of the measured impedance at each frequency point, or equal weights are used. The purpose is to balance the interference of impedance amplitude differences between high and low frequency ranges on the fitting results and prevent the large impedance region at low frequencies from masking the characteristics of weak high-frequency responses.

[0047] To ensure that CNLS fitting not only yields the smallest mathematical residual but also guarantees that the solved parameters have genuine electrochemical physical meaning, the initial values ​​and constraint ranges of the parameter vector θ to be fitted must be carefully set. The parameter vector θ includes the solution resistance R. s The system comprises a first resistor R1, a first capacitor C1, a second resistor R2, a second capacitor C2, a third resistor R3, and a third capacitor C3. The method of setting the initial values ​​directly affects whether the iterative algorithm can quickly converge to the global optimum. In this embodiment, the initial values ​​of each resistor and capacitor no longer rely on blind guessing, but are estimated based on the time constant peaks of each layer obtained from the Distributed Relaxation Time (DRT) decomposition. For example, the initial value of the solution resistance Rs is taken as the real part of the measured impedance at the highest frequency point; the initial values ​​of each layered resistor are calculated based on the relaxation time value and peak amplitude of the corresponding DRT peak; and the initial values ​​of each layered capacitor are inversely calculated using the capacitance calculation formula by using the characteristic frequency of the corresponding peak and the estimated resistance value. This method of setting initial values ​​based on objective DRT estimation ensures that the iteration starting point is located within the neighborhood of the physical true solution, greatly reducing the risk of falling into the mathematical local optimum trap.

[0048] More importantly, strict constraints must be set for each parameter in the parameter vector θ, including upper and lower limits. The existence of constraints is the boundary between a "mathematical fitting game" and "physical parameter inversion." Without constraints, the CNLS algorithm, in pursuit of the minimum objective function Φ, might fit a resistance parameter that should represent the barrier capability of the dense film as a negative or extremely small meaningless value, which is absolutely impossible in electrochemical physics. For example, the second resistance R2 represents the resistance of the inner dense film to charge transfer. Its physical nature dictates that it must be a positive real number and usually on the order of magnitude. Allowing it to freely fall to negative values ​​or close to zero during iterations might result in a smaller mathematical residual, but the solution obtained would completely deviate from the true physical mechanism by which the inner film provides protection. Therefore, by imposing constraints, all parameters are forced to be confined to a range with clear physical meaning during iterative updates. For example, the solution resistance is confined to between 0.01 and 1000 ohm square centimeters, and the resistance of each layer is confined to a positive range that matches the protective properties of its film. This ensures that the inversion result is not only the mathematically optimal solution but also the physically real solution.

[0049] After setting the initial values ​​and constraints, the Levenberg-Marquardt iterative algorithm is used to minimize the objective function Φ. In each iteration, the algorithm calculates the partial derivatives of the objective function with respect to each parameter to construct a Jacobian matrix, and dynamically adjusts the damping factor to balance the step size of gradient descent and Newton's method, updating the parameter vector accordingly. The iterative convergence criterion is an objective standard for determining when the inversion calculation terminates. In this embodiment, the convergence criterion includes at least one of the following conditions: Condition A, the relative change of the objective function between two consecutive iterations is less than a preset threshold, for example, one ten-thousandth, indicating that the residual cannot be further reduced; Condition B, the norm of the parameter vector change is less than a preset threshold, for example, one millionth, indicating that the parameters have stabilized and no longer drift; Condition C, a preset maximum number of iterations is reached, for example, 200 iterations, as a safe exit mechanism to prevent infinite loops. When one of the above convergence criteria is met, the algorithm terminates the iteration, outputs the values ​​of the first, second, and third resistors corresponding to the optimal parameter vector, and completes the inversion process.

[0050] Specifically, the inversion calculation of the first resistance R1 of the outer porous layer, the second resistance R2 of the inner dense layer, and the third resistance R3 of the substrate / film interface in the CO2 pipeline corrosion product film includes the following steps: Step 1: EIS Data Acquisition and Preprocessing: Electrochemical sensors are installed on the inner wall of the CO2 pipeline to collect electrochemical impedance spectroscopy data of the pipeline inner wall covered with corrosion product film within a preset frequency range, wherein the frequency range is 10. - ² Hz~10 5Hz, with at least 10 frequency points collected for every ten octaves; ω is measured at each frequency point. i The complex impedance value Zmeas(ω) i )=Z'meas(ω i )+jZ''meas(ω i ), where Z'meas is the real part, Z''meas is the imaginary part, and j is the imaginary unit; Step 2: Establish the impedance expression for the multilayer equivalent circuit model.

[0051] A multilayer equivalent circuit model is constructed, consisting of a solution resistor Rs, a first parallel branch, a second parallel branch, and a third parallel branch connected in series. The first parallel branch is composed of a first resistor R1 and a first capacitor C1 connected in parallel, representing the outer porous film layer; the second parallel branch is composed of a second resistor R2 and a second capacitor C2 connected in parallel, representing the inner dense film layer; and the third parallel branch is composed of a third resistor R3 and a third capacitor C3 connected in parallel, representing the substrate / film interface. The expression for the total impedance Zmodel(ω) of the multilayer equivalent circuit model is:

[0052] In the formula, ω=2πf is the angular frequency, f is the frequency, and j is the imaginary unit; Step 3: Construct the objective function for complex nonlinear least squares fitting.

[0053] The complex impedance Zmeas(ω) at each frequency point measured in step one i The predicted value Zmodel(ω) from step two is the same as the predicted value from step two. i The weighted sum of squared residuals between the two points is the objective function Φ:

[0054] In the formula, N is the total number of frequency points, w i The weighting coefficient for the i-th frequency point is 1 / |Zmeas(ω). i |² or equal weights; Z'model and Z''model are the real and imaginary parts of Zmodel, respectively; Step 4: Set the initial values ​​and constraint ranges of the parameters to be fitted.

[0055] The parameter vector to be fitted is defined as θ=[Rs,R1,C1,R2,C2,R3,C3], and initial values ​​and constraint ranges are set for each parameter. The constraint ranges include upper and lower limits to ensure the fitting result has physical meaning. The initial values ​​and constraint ranges for each parameter are shown in Table 1. Table 1

[0056] Step 5: Use an iterative optimization algorithm to solve for the optimal parameters.

[0057] The Levenberg-Marquardt algorithm is used to iteratively minimize the objective function Φ. In each iteration, the partial derivatives (Jacobi matrix) of the objective function with respect to each parameter are calculated, and the parameter vector is updated.

[0058] In the formula, θ k Let J be the parameter vector for the k-th iteration. k Let r be a Jacobian matrix. k Let μ be the residual vector. k I is the damping factor, and I is the identity matrix; The iterative convergence criterion is one of the following conditions: Condition A: The relative change of the objective function in two consecutive iterations is less than the preset threshold ε1=10. -4 ; Condition B: The norm of the change in the parameter vector is less than the preset threshold ε2=10 -6 ; Condition C: Reaching the preset maximum number of iterations K max =200 times; Step 6: Output the resistance parameters obtained from the inversion calculation.

[0059] When the convergence condition is met, the values ​​of the first resistor R1, the second resistor R2, and the third resistor R3 in the optimal parameter vector θ* are output. Each resistor value includes an estimated value and a 95% confidence interval.

[0060] It should be understood that although the embodiments of this application detail the specific numerical values ​​of the Levenberg-Marquardt algorithm and its convergence criterion, other nonlinear optimization algorithms such as genetic algorithms or particle swarm optimization can be used for global search in other embodiments. The convergence threshold can also be adaptively adjusted according to the noise level of the measured data, as long as the optimal fitting of the physically constrained complex domain can be achieved. In the embodiments of this application, through the above-mentioned rigorous mathematical structure and physical constraints, the functionally limited "inversion" is translated into specific algorithmic steps and formula iterations, ensuring the rigor and irreplaceability of the layered resistance solution.

[0061] The following section details the specific judgment logic and calculation model for estimating the remaining life of CO2 pipelines. The layered structure of the corrosion product film does not drive the corrosion process statically; rather, it dynamically changes as the film evolves. The resistance values ​​of each layer include: the first resistance of the outer porous layer, the second resistance of the inner dense layer, and the third resistance of the substrate film interface. Based on the resistance values ​​of each layer of the corrosion product film, the remaining life of the CO2 pipeline is estimated using the following parallel and mutually exclusive judgment and calculation paths.

[0062] If the second resistance is greater than the third resistance, and the second resistance is greater than the first resistance, then the corrosion rate of the CO2 pipeline is determined to be controlled by the inner dense film. The initial remaining lifespan of the CO2 pipeline is calculated based on the time decay function of the second resistance, from the current moment until the second resistance decreases to the preset failure threshold. The physical mechanism of this determination rule is that in an electrochemical corrosion system, the film layer with the greatest charge transfer resistance inevitably controls the overall corrosion rate. When the value of the second resistance is greater than both the third and first resistances, it means that the inner dense film has the highest barrier to the penetration of corrosive media and charge transfer, becoming the bottleneck step in the corrosion process. At this time, although the pore penetration of the outer loose film and the metal dissolution reaction at the matrix interface exist, they are limited by the barrier of the inner dense film and can only proceed at a very slow rate. The overall corrosion rate is entirely determined by the degree of decay of the inner dense film. Therefore, in this case, the lifespan is estimated using a time decay function based on the second resistance. This time decay function is specifically an exponential decay model, meaning that the second resistance decays exponentially with time, and the decay rate constant is obtained by fitting historical monitoring data. This function can be used to calculate the remaining time required for the second resistance value to decay to a preset failure threshold from the current moment. This remaining time is the initial remaining lifetime L2. The preset failure threshold R... 2,crit This is the critical resistance value for the loss of protective function of the inner membrane, determined based on laboratory accelerated corrosion tests or engineering experience. Its engineering value typically ranges from 50 to 200 ohms per square centimeter. It should be understood that although the embodiments of this application list a typical range of 50 to 200 ohms per square centimeter, this failure threshold can be adaptively adjusted according to the specific corrosion environment and safety margin requirements in different CO2 transport conditions or piping systems, as long as it reflects the critical turning point where the inner membrane degrades from a dense barrier to a large-area failure.

[0063] If the third resistance is greater than the second resistance and also greater than the first resistance, then the corrosion rate is determined to be controlled by the substrate / film interface. The current corrosion rate of the substrate / film interface is calculated based on the third resistance. Based on this current corrosion rate, the remaining lifetime of the substrate / film interface is calculated using a uniform corrosion model as the initial remaining lifetime of the CO2 pipeline. Specifically, when the third resistance dominates, the physical mechanism indicates that the inner dense film has been severely damaged or extensively peeled off, losing its protective function as the main barrier layer. At this point, the corrosive medium reaches the substrate surface almost unimpeded. The resistance to charge transfer mainly comes from the kinetic energy barrier of the substrate metal dissolution reaction itself. That is, the corrosion rate is dominated by the electrochemical reaction at the substrate / film interface, and the thinning mode of the pipeline wall changes from localized or inhibited corrosion limited by the film layer to rapid thinning dominated by uniform corrosion. Therefore, in this case, the current corrosion rate of the substrate / film interface is calculated based on the third resistance. Specifically, the Stern-Geary equation is used to convert the third resistance into corrosion current density, thereby deriving the corrosion rate. Subsequently, following the uniform corrosion wall thickness reduction model, the difference between the original pipe wall thickness and the minimum allowable wall thickness was divided by the current corrosion rate to calculate the remaining lifetime of the substrate film interface, which was then used as the initial remaining lifetime L3. This model directly reflects the remaining service time of the pipe under interface-controlled conditions when it is uniformly thinned to the critical failure thickness.

[0064] If the first resistance value is greater than the second resistance value, which in turn is greater than the third resistance value, then the remaining time required for the second resistance value to decrease to a preset failure threshold is calculated based on the time decay function of the second resistance value. The current corrosion rate of the substrate film interface is calculated based on the third resistance value, and the remaining lifetime of the substrate film interface is calculated based on the current corrosion rate using a uniform corrosion model. The remaining time and remaining lifetime are then weighted according to the second and third resistance values ​​to obtain the initial remaining lifetime of the CO2 pipeline. Specifically, when the first resistance is greater than the second resistance and the second resistance is greater than the third resistance, it means that the outer porous film exhibits an abnormally high resistance state, while the resistance of the inner dense film and the substrate film interface is lower than that of the outer film. The corrosion process is not completely dominated by a single film layer, but rather the decay of the inner dense film and the metal dissolution reaction at the substrate film interface compete and drive each other in parallel. Although the inner dense film offers less resistance than the outer porous film, it still hinders the penetration of corrosive media, and its decay trend determines the timescale of the film's protective decay. Simultaneously, the charge transfer resistance at the substrate film interface is lowest, and the metal dissolution reaction proceeds at a relatively rapid rate, determining the rate of wall thinning. Therefore, in this case, the initial remaining lifetime is no longer simply attributed to the prediction result of a single mechanism, but rather a weighted fusion of lifetime estimates from both mechanisms. Specifically, the remaining time T2 required for the second resistance to decrease to the preset failure threshold is calculated based on the time decay function of the second resistance. This remaining time reflects the timescale required for the inner dense film to decay from its current blocking state to loss of protection. Simultaneously, the current corrosion rate at the substrate film interface is calculated based on the third resistance, and the remaining lifetime L3 at the substrate film interface is calculated according to the uniform corrosion model. This remaining lifetime reflects the service time required for the pipe wall thickness to thin to the critical failure thickness under interface control mode. Subsequently, the remaining time T2 and the remaining lifetime L3 are weighted according to the second and third resistances to obtain the initial remaining lifetime. The higher the second resistance, the greater the weight of the inner film control mechanism, and the more the initial remaining lifetime leans towards the inner film decay timescale; the higher the third resistance, the greater the weight of the interface control mechanism, and the more the initial remaining lifetime leans towards the interface corrosion thinning lifetime scale. Through this dynamic weighting, the lifetime prediction results of the two dominant mechanisms are merged into a transitional initial remaining lifetime, thereby achieving uninterrupted and accurate tracking of the smooth transition period of the corrosion mechanism and preventing abrupt distortion of the prediction results at the mechanism switching critical point.

[0065] Furthermore, if the decrease in the first resistance exceeds a set threshold, the remaining life of the CO2 pipeline is obtained by multiplying the initial remaining life by a correction factor based on the decrease in the first resistance; if the decrease in the first resistance does not exceed the set threshold, the initial remaining life is determined as the remaining life of the CO2 pipeline.

[0066] Specifically, a sharp drop in the first resistance is a clear electrochemical signal indicating localized detachment of the outer porous film. The threshold is typically set at a decrease exceeding 30%. The physical mechanism behind this determination is that while the outer porous film does not provide primary corrosion resistance, it acts as a physical barrier, buffering the direct impact of corrosive media and limiting the abnormal accumulation of corrosion products in localized areas. When the first resistance decreases by more than 30% within a continuous sampling period, it signifies significant localized detachment of the outer porous film, rather than slow natural degradation. Once localized detachment occurs, it disrupts the original corrosion electrochemical equilibrium, creating an exposed anode in the detached area, while the surrounding area still covered by the film becomes a large cathode. This area effect of a large cathode and a small anode greatly accelerates the concentration of localized corrosion current, causing pitting or localized thinning rates to far exceed the average rate calculated based on the overall control of the inner film or interface. Therefore, the initial remaining lifetime calculated based on the master control steps must be reduced and corrected. The correction factor α ranges from 0.7 to 0.9, and its mapping relationship with the decrease in the first resistance is as follows: when the decrease is between 30% and 50%, it is judged as mild localized peeling, and the correction factor α is 0.9; when the decrease is between 50% and 70%, it is judged as moderate localized peeling, and the correction factor α is 0.8; when the decrease is greater than 70%, it is judged as severe large-area peeling with extremely high risk of localized corrosion, and the correction factor α is 0.7. Multiplying the initial remaining life by the corresponding correction factor α yields the final estimated remaining life of the CO2 pipeline. This correction mechanism is essentially an empirical defense against the risk of accelerated localized corrosion, avoiding misjudgment that underestimates the potential for sudden failure by relying solely on the overall decay model. If the decrease in the first resistance does not exceed 30%, it is considered that the outer film has only undergone normal slow decay or slight peeling, without triggering a significant localized accelerated effect, and no reduction is required; the initial remaining life is directly determined as the final remaining life.

[0067] As a supplementary defensive variant of the judgment conditions in the embodiments of this application, in the actual complex corrosion evolution, sometimes there is a transitional state in which the resistance of the interface between the inner dense film and the substrate film is not much different, or the first resistance is the largest, that is, the outer loose film abnormally exhibits a high resistance state. For such a transitional state, if the single model of inner film control or interface control is directly applied, the dynamic influence of the parallel competition of multiple mechanisms may be ignored. Therefore, when the judgment conditions are not met, such as when the second resistance is the largest or the third resistance is the largest, for example when the first resistance is the largest or the relationship between the resistances is fluctuating, it can be judged as a transitional state, and a weighted average model is used for prediction. Specifically, the initial lifetime L2 calculated based on inner film control and the initial lifetime L3 calculated based on interface control are weighted according to the numerical ratio of the second resistance and the third resistance, that is, the larger the second resistance, the greater the weight of the inner film control mechanism, and the larger the third resistance, the greater the weight of the interface control mechanism. By using this dynamic weighting, the lifetime prediction results of the two dominant mechanisms are merged into a transitional remaining lifetime Lmix, thereby achieving uninterrupted and accurate tracking of the smooth transition period of the corrosion mechanism and preventing abrupt distortion of the prediction results at the mechanism switching critical point.

[0068] Specifically, the remaining lifespan of a CO2 pipeline is estimated based on the resistance values ​​of each layer of the corrosion product film, including the following steps: Step 1: Obtain three layered resistors.

[0069] Electrochemical sensors were deployed on the inner wall of a CO2 pipeline to collect electrochemical impedance spectroscopy (EIS) data of the region covered by a corrosion product film. The relaxation time distribution (DRT) technique was used to decompose the EIS spectrum into three independent time constant peaks belonging to the outer loose film layer, the inner dense film layer, and the substrate / film interface. Based on the DRT decomposition results, a three-layer equivalent circuit model was constructed, consisting of a first resistor R1 and a first capacitor C1 connected in parallel to represent the outer loose film layer, a second resistor R2 and a second capacitor C2 connected in parallel to represent the inner dense film layer, and a third resistor R3 and a third capacitor C3 connected in parallel to represent the substrate / film interface, connected in series with the solution resistance Rs. The values ​​of R1, R2, and R3 were obtained through complex nonlinear least squares fitting, with units of Ω·cm².

[0070] Step 2: Establish the time decay function for each resistor.

[0071] Time series tracking is performed on R1, R2, and R3 obtained from the inversion in step one, and their respective time decay functions are established, where: For the second resistor R2, an exponential decay model is adopted:

[0072] In the formula, The second resistance value at the initial moment. The second resistance decay rate constant is obtained by fitting historical data, and the unit is days. - ¹; For the third resistor R3, a linear or exponential decay model is used: ,or,

[0073] In the formula, The slope is linear decay. It is the exponential decay rate constant; For the first resistor R1, no long-term decay function is established; it is only used for sudden drop event monitoring and remaining lifetime correction.

[0074] Step 3: Determine the current master control step and select the prediction model.

[0075] like and If the current corrosion rate is determined to be controlled by the inner dense film, proceed to step fourA. like and If the current corrosion rate is determined to be controlled by the substrate / film interface, proceed to step fourB. like and If neither of the above two conditions is met, it is determined to be a transitional state, and proceeds to step four C.

[0076] Step 4A: Remaining lifetime estimation under inner membrane control mode.

[0077] Based on the R2 exponential decay model established in step two, a preset failure threshold for the inner membrane is determined. This threshold is determined based on laboratory accelerated corrosion test calibration or engineering experience, and its value ranges from 50 to 200 Ω·cm²; the remaining life is calculated using the following formula. :

[0078] In the formula, The second resistance value at the current moment; calculated This is the estimated remaining lifespan, expressed in days.

[0079] Step 4B: Remaining lifespan estimation in interface control mode.

[0080] The protective film has been determined to be largely ineffective, and the corrosion rate is now dominated by charge transfer processes. The current corrosion rate is calculated using the Stern-Geary equation based on the third resistor R3. :

[0081] In the formula, The Stern-Geary constant is taken as 26 mV for CO2 corrosion; then the remaining lifetime is estimated using a uniform corrosion model. :

[0082] In the formula, The original wall thickness of the pipe. The minimum allowable wall thickness is shown in mm; a high-priority warning is also triggered.

[0083] Step 4C: Remaining lifetime estimation under transition conditions.

[0084] A weighted average model is used to weight the prediction results of steps 4A and 4B according to the resistance value:

[0085] In the formula, Calculate according to step 4A (assuming the lifespan is controlled by the inner membrane). Calculate according to step 4B (assuming the lifespan of the interface control). This is the estimated remaining lifespan.

[0086] Step 5: Outer membrane peeling warning and lifespan correction.

[0087] The first resistance R1 is continuously monitored. When the decrease of R1 exceeds 30% within two consecutive sampling periods (each sampling period is 1 to 24 hours), it is determined that the outer loose film has locally peeled off, triggering a local corrosion risk warning. The remaining lifetime L calculated in steps four A, four B, or four C is multiplied by a correction factor α, where the value of α ranges from 0.7 to 0.9. The specific value of α is determined according to the decrease of R1: α=0.9 when the decrease is 30% to 50%, α=0.8 when the decrease is 50% to 70%, and α=0.7 when the decrease is greater than 70%.

[0088] Step 6: Output the final estimated remaining lifetime.

[0089] It should be understood that the above is explanatory and not restrictive. Those skilled in the art can reasonably adjust the value of the failure threshold, the specific form of the attenuation function, or the mapping range of the correction coefficient according to the specific pipeline material and transportation conditions. As long as it follows the physical mechanism of controlling the corrosion rate by the maximum charge transfer resistance and the reduction logic of localized corrosion accelerated by localized peeling of the outer film, it falls within the scope of the technical concept protected by this invention.

[0090] Furthermore, based on the resistance values ​​of each layer of the corrosion product film, after estimating the remaining lifespan of the CO2 pipeline, an early warning signal can be output when the remaining lifespan of the CO2 pipeline is lower than the safety threshold.

[0091] Specifically, the safety threshold is not set arbitrarily, but is determined based on the engineering response cycle and handling logic of pipeline operation and maintenance. In carbon capture and storage (CCS) projects, once a pipeline is at risk of corrosion failure, the operation and maintenance team needs a certain amount of time to activate emergency plans, allocate maintenance resources, and even arrange pipeline shutdown and replacement. If the safety threshold is set too short, for example, only a few days before the alarm, the operation and maintenance team will not have enough time to prevent a leak; if it is set too long, it may lead to frequent false alarms, increasing unnecessary operation and maintenance costs and panic. Therefore, the logic for determining the safety threshold must match the typical engineering handling cycle. As a preferred implementation method, the safety threshold can be set to 180 days or 365 days. The 180-day threshold usually corresponds to a medium-term response cycle that requires immediate on-site flaw detection and local repair, while the 365-day threshold corresponds to a long-term planning cycle that requires inclusion in the annual overhaul plan and preparation for pipeline replacement.

[0092] It should be understood that although 180 days and 365 days are listed as two typical engineering time nodes in this application embodiment, the safety threshold can also be set to 90 days, 730 days or other values ​​under different pipeline operation systems or regulatory requirements, as long as it can reserve a sufficient and reasonable response window for subsequent engineering disposal.

[0093] When the calculated final remaining lifespan falls below the safety threshold, an early warning signal is immediately output to break down information silos and transform abstract resistance decay data into intuitive engineering decision-making instructions. The carrier of the early warning signal should possess high reliability and penetration to ensure that information reaches relevant decision-makers without delay. Specifically, the carrier of the early warning signal can include on-site audible and visual alarms issued by audible and visual alarm devices, which have the most direct stimulating effect on personnel on duty at pipeline inspection stations or control rooms; it can also include pop-up prompts on the monitoring terminal interface, which forcefully interrupt the operator's current secondary work through eye-catching visual elements, guiding them to focus on pipeline risks; and it can also include mobile messages pushed through remote communication networks, such as SMS, email, or push notifications from a dedicated safety monitoring APP, enabling management or emergency experts who are not on-site to monitor the pipeline status in real time.

[0094] It should be understood that the above three carrier forms can be used individually or in combination. For example, in a high-risk situation, on-site sound and light, interface pop-ups and remote push can be triggered simultaneously to form a multi-redundant warning loop to prevent information loss caused by a single communication link failure.

[0095] To further refine risk management and avoid the waste of operation and maintenance resources caused by a one-size-fits-all alarm mode, this application embodiment adopts a four-level early warning system, which strictly binds the remaining lifespan range with different risk severity levels and engineering response actions.

[0096] The first level is a low-risk warning level, triggered when the remaining lifespan is greater than 365 days. At this time, pipeline corrosion is in a slow evolution stage, the protective film is intact, and the system only outputs routine periodic status reports or low-priority interface indicators. No emergency intervention measures are required, and the maintenance team only needs to include it in the routine annual monitoring plan.

[0097] The second level is a medium-risk warning level, triggered when the remaining lifetime is between 180 and 365 days. At this point, the inner dense membrane may have shown an accelerated degradation trend or the outer membrane may show slight signs of peeling. The system outputs a medium-priority warning signal, such as an interface pop-up notification and email notification. The corresponding engineering action is to increase the monitoring frequency, for example, shortening the EIS data collection cycle from once a week to once a day, and arranging personnel to conduct targeted inspections during the next planned shutdown.

[0098] Level 3 is a high-risk warning level, triggered when the remaining service life is between 30 and 180 days. At this point, the corrosion control mechanism may have switched from inner membrane control to interface control, or the outer membrane may have experienced moderate to severe localized peeling, and the pipe wall thickness is rapidly decreasing. The system outputs high-priority warning signals, including on-site audible and visual alarms and real-time remote push notifications. The corresponding engineering actions are to immediately activate the emergency plan, prepare spare parts, and assess whether pressure reduction operation or advance scheduling of shutdown and maintenance is necessary.

[0099] Level 4 is the emergency warning level, triggered when the remaining lifespan is less than 30 days, or when the outer membrane's localized peeling correction mechanism is activated. At this point, the pipeline faces an extremely high risk of localized perforation or sudden leakage. The system outputs the highest priority emergency alarm, activating all carrier forms and continuously sounding an alarm until manual confirmation. The corresponding engineering response is to immediately shut down the pipeline safely, evacuate personnel from the potentially affected area, and implement emergency repairs.

[0100] This four-level early warning system not only enables the transformation from predictive data to decision-making instructions, but also establishes a complete risk response echelon from gradual change to sudden change, allowing for the precise allocation of operational resources.

[0101] It should be understood that the specific values ​​of the above safety thresholds and the ranges for the four warning levels are interpretive rather than restrictive. Those skilled in the art can adaptively adjust the thresholds and level ranges based on specific pipeline transport pressures, pipe specifications, environmental sensitivity, and other factors. As long as they follow the logic that the shorter the remaining lifespan, the higher the warning priority, they all fall within the scope of the technical concept protected by this invention.

[0102] Based on the above embodiments, this application provides a CO2 pipeline remaining life prediction system, see below. Figure 2 As shown, the CO2 pipeline remaining life prediction system 200 provided in this application embodiment includes at least: The data acquisition unit 201 is used to acquire electrochemical impedance spectroscopy data of corrosion product film on the inner wall of CO2 pipeline collected by an electrochemical sensor array embedded in the inner wall of CO2 pipeline. The resistance inversion unit 202 is used to invert the resistance values ​​of each layer of the corrosion product film based on electrochemical impedance spectroscopy data and using a multilayer equivalent circuit model that matches the layered structure of the corrosion product film. The lifespan prediction unit 203 is used to predict the remaining lifespan of the CO2 pipeline based on the resistance values ​​of each layer of the corrosion product film.

[0103] In one possible implementation, the CO2 pipeline remaining life prediction system 200 provided in this application embodiment further includes: Model building unit 204 is used to identify the layers of the corrosion product film based on electrochemical impedance spectroscopy data; and to build a multilayer equivalent circuit model based on the layers of the corrosion product film.

[0104] In one possible implementation, the model building unit 204 is used to decompose the electrochemical impedance spectroscopy data using the relaxation time distribution to obtain each time constant peak; based on the correspondence between the time constant peak range and each layer of the corrosion product film, the layer to which each time constant peak belongs is identified.

[0105] In one possible implementation, the layered structure of the corrosion product film includes: an outer porous layer, an inner dense layer, and a substrate film interface; the model building unit 204 is used to build a first equivalent circuit for the outer porous film layer, which is formed by a first resistor and a first capacitor connected in parallel; to build a second equivalent circuit for the inner dense film layer, which is formed by a second resistor and a second capacitor connected in parallel; to build a third equivalent circuit for the substrate film interface, which is formed by a third resistor and a third capacitor connected in parallel; and to connect the first, second, and third equivalent circuits in series with the corrosive solution resistor to form a multilayer equivalent circuit model.

[0106] In one possible implementation, the layered structure of the corrosion product film includes: an outer porous layer, an inner dense layer, and a substrate film interface; the resistance inversion unit 202 is used to calculate the first resistance of the outer porous layer, the second resistance of the inner dense layer, and the third resistance of the substrate film interface based on electrochemical impedance spectroscopy data, using a multilayer equivalent circuit model and complex nonlinear least squares fitting.

[0107] In one possible implementation, the resistance values ​​of each layer include: a first resistance value of the outer porous layer, a second resistance value of the inner dense layer, and a third resistance value of the substrate film interface; the lifetime estimation unit 203 is used to calculate, according to a time decay function based on the second resistance value, the remaining time required for the second resistance value to decrease to a preset failure threshold from the current moment as the initial remaining lifetime of the CO2 pipeline if the second resistance value is greater than the third resistance value and greater than the first resistance value; if the third resistance value is greater than the second resistance value and greater than the first resistance value, the current corrosion rate of the substrate film interface is calculated based on the third resistance value, and the current corrosion rate of the substrate film interface is calculated based on the current resistance value. The corrosion rate is calculated using a uniform corrosion model, and the remaining life of the substrate film interface is used as the initial remaining life of the CO2 pipeline. If the first resistance value is greater than the second resistance value, which is greater than the third resistance value, the remaining time required for the second resistance value to decrease to a preset failure threshold is calculated using a time decay function based on the second resistance value. The current corrosion rate of the substrate film interface is calculated based on the third resistance value, and the remaining life of the substrate film interface is calculated using a uniform corrosion model based on the current corrosion rate. The remaining time and remaining life are weighted according to the second and third resistance values ​​to obtain the initial remaining life of the CO2 pipeline.

[0108] In one possible implementation, the CO2 pipeline remaining life prediction system 200 provided in this application further includes: The warning output unit 205 is used to output a warning signal when the remaining life of the CO2 pipeline is lower than the safety threshold.

[0109] It should be noted that the principle of the CO2 pipeline remaining life prediction system 200 provided in this application embodiment to solve the technical problem is similar to the CO2 pipeline remaining life prediction method provided in this application embodiment. Therefore, the implementation of the CO2 pipeline remaining life prediction system 200 provided in this application embodiment can refer to the implementation of the CO2 pipeline remaining life prediction method provided in this application embodiment, and the repeated parts will not be described again.

[0110] After introducing the CO2 pipeline remaining life prediction method and system provided in the embodiments of this application, the electronic equipment provided in the embodiments of this application will be briefly introduced next.

[0111] See Figure 3As shown, the electronic device 300 provided in this application embodiment includes at least a processor 301, a memory 302, and a computer program stored in the memory 302 and executable on the processor 301. When the processor 301 executes the computer program, it implements the CO2 pipeline remaining life prediction method provided in this application embodiment.

[0112] In one possible implementation, processor 301 can be a single processing element or a collective term for multiple processing elements. For example, processor 301 can be a central processing unit (CPU), or one or more integrated circuits configured to implement the CO2 pipeline remaining life prediction method provided in the embodiments of this application. Specifically, processor 301 can be a general-purpose processor, including but not limited to CPUs, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0113] In one possible implementation, memory 302 may include a readable medium in the form of volatile memory, such as random access memory (RAM) 3021 and / or cache memory 3022, and may further include read-only memory (ROM) 3023; memory 302 may also include a program tool 3025 having a set (at least one) of program modules 3024, including but not limited to: operating subsystem, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0114] In one possible implementation, the electronic device 300 provided in this application embodiment may further include a bus 303 connecting different components (including processor 301 and memory 302). The bus 303 represents one or more types of bus structures, including memory bus, peripheral bus, local area bus, etc.

[0115] In one possible implementation, the electronic device 300 can also communicate with one or more devices that enable a user to interact with the electronic device 300 (e.g., mobile phones, computers, etc.), and / or with external devices 304 such as devices that enable the electronic device 300 to communicate with one or more other electronic devices 300 (e.g., routers, modems, etc.). This communication can be performed via an input / output (I / O) interface 305. Furthermore, the electronic device 300 can also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter 306. Figure 3 As shown, network adapter 306 communicates with other modules of electronic device 300 via bus 303. It should be understood that, although... Figure 3 As not shown, other hardware and / or software modules may be used in conjunction with electronic device 300, including but not limited to microcode, device drivers, redundant processors, external disk drive arrays, Redundant Arrays of Independent Disks (RAID) subsystems, tape drives, and data backup storage subsystems.

[0116] It should be noted that, Figure 3 The electronic device 300 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0117] Furthermore, this application also provides a computer-readable storage medium storing computer instructions that, when executed by a processor, implement the CO2 pipeline remaining life prediction method provided in this application. Specifically, the computer instructions may be built into or installed in a processor, so that the processor implements the CO2 pipeline remaining life prediction method provided in this application by executing the built-in or installed computer instructions.

[0118] Of course, the CO2 pipeline remaining life prediction method provided in the embodiments of this application can also be implemented as a program product, which includes program code. When the program code is executed by a processor, it implements the CO2 pipeline remaining life prediction method provided in the embodiments of this application.

[0119] The program product provided in this application embodiment can be any combination of one or more readable media, wherein the readable media can be a readable signal medium or a readable storage medium, and the readable storage medium can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or apparatus, or any combination thereof. Specifically, more specific examples of readable storage media (a non-exhaustive list) include: electrical connections with one or more wires, portable disks, hard disks, RAM, ROM, erasable programmable read-only memory (EPROM), optical fibers, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0120] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0121] Furthermore, although the operations of the method of this application are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0122] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0123] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A method for predicting the remaining life of a CO2 pipeline, characterized in that, include: Electrochemical impedance spectroscopy data of corrosion product films on the inner wall of the CO2 pipeline were acquired by an electrochemical sensor array embedded in the inner wall of the CO2 pipeline. Based on the electrochemical impedance spectroscopy data, a multilayer equivalent circuit model matching the layered structure of the corrosion product film is used to invert the resistance value of each layer of the corrosion product film. The remaining lifespan of the CO2 pipeline is estimated based on the resistance values ​​of each layer of the corrosion product film.

2. The method for predicting the remaining life of a CO2 pipeline as described in claim 1, characterized in that, After acquiring the electrochemical impedance spectroscopy data of the corrosion product film on the inner wall of the CO2 pipeline collected by the electrochemical sensor array embedded in the inner wall of the CO2 pipeline, the process further includes: Based on the electrochemical impedance spectroscopy data, the various layers of the corrosion product film are identified; Based on the various layers of the corrosion product film, the multilayer equivalent circuit model is constructed.

3. The method for predicting the remaining life of a CO2 pipeline as described in claim 2, characterized in that, Based on the electrochemical impedance spectroscopy data, the various layers of the corrosion product film are identified, including: The electrochemical impedance spectroscopy data were decomposed using the relaxation time distribution to obtain the peaks of each time constant; Based on the correspondence between the time constant peak range and the various layers of the corrosion product film, the layer to which each time constant peak belongs is identified.

4. The method for predicting the remaining life of a CO2 pipeline as described in claim 2, characterized in that, The layered structure of the corrosion product film includes: an outer porous layer, an inner dense layer, and a substrate film interface; Based on the various layers of the corrosion product film, the multilayer equivalent circuit model is constructed, including: A first equivalent circuit is constructed for the outer porous film layer by a first resistor and a first capacitor connected in parallel. A second equivalent circuit is constructed for the inner dense film layer by a second resistor and a second capacitor connected in parallel. A third equivalent circuit, consisting of a third resistor and a third capacitor connected in parallel, is constructed for the substrate film interface; The first equivalent circuit, the second equivalent circuit, and the third equivalent circuit are connected in series, and then connected in series with the corrosive solution resistor to form the multilayer equivalent circuit model.

5. The method for predicting the remaining life of a CO2 pipeline as described in claim 1, characterized in that, The layered structure of the corrosion product film includes: an outer porous layer, an inner dense layer, and a substrate film interface; Based on the electrochemical impedance spectroscopy data, a multilayer equivalent circuit model matching the layered structure of the corrosion product film is used to invert the resistance values ​​of each layer of the corrosion product film, including: Based on the electrochemical impedance spectroscopy data, using the multilayer equivalent circuit model, the first resistance value of the outer porous layer, the second resistance value of the inner dense layer, and the third resistance value of the substrate membrane interface are calculated by complex nonlinear least squares fitting.

6. The method for predicting the remaining life of a CO2 pipeline as described in claim 1, characterized in that, The resistance values ​​of each layer include: the first resistance value of the outer porous layer, the second resistance value of the inner dense layer, and the third resistance value of the matrix film interface; Based on the resistance values ​​of each layer of the corrosion product film, the remaining lifespan of the CO2 pipeline is estimated, including: If the second resistance value is greater than the third resistance value, which is greater than the first resistance value, then the remaining time required for the second resistance value to drop to a preset failure threshold is calculated based on the time decay function of the second resistance value, and this remaining time is taken as the initial remaining life of the CO2 pipeline. If the third resistance value is greater than the second resistance value and the first resistance value, then the current corrosion rate of the substrate film interface is calculated based on the third resistance value. Based on the current corrosion rate, the remaining lifetime of the substrate film interface is calculated according to the uniform corrosion model as the initial remaining lifetime of the CO2 pipeline. If the first resistance value is greater than the second resistance value, which is greater than the third resistance value, then the remaining time required for the second resistance value to decrease to a preset failure threshold is calculated based on the time decay function of the second resistance value. The current corrosion rate of the substrate film interface is calculated based on the third resistance value. Based on the current corrosion rate, the remaining lifetime of the substrate film interface is calculated according to a uniform corrosion model. The remaining time and the remaining lifetime are weighted according to the second resistance value and the third resistance value to obtain the initial remaining lifetime of the CO2 pipeline.

7. The method for predicting the remaining life of a CO2 pipeline as described in any one of claims 1-6, characterized in that, After estimating the remaining lifespan of the CO2 pipeline based on the resistance values ​​of each layer of the corrosion product film, the process further includes: When the remaining lifespan of the CO2 pipeline is below the safety threshold, a warning signal is output.

8. A CO2 pipeline remaining life prediction system, characterized in that, include: The data acquisition unit is used to acquire electrochemical impedance spectroscopy data of the corrosion product film on the inner wall of the CO2 pipeline collected by the electrochemical sensor array embedded in the inner wall of the CO2 pipeline. The contribution inversion unit is used to invert the resistance value of each layer of the corrosion product film based on the electrochemical impedance spectroscopy data and using a multilayer equivalent circuit model that matches the layered structure of the corrosion product film. A lifespan prediction unit is used to predict the remaining lifespan of the CO2 pipeline based on the resistance values ​​of each layer of the corrosion product film.

9. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the CO2 pipeline remaining life prediction method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement the CO2 pipeline remaining life prediction method as described in any one of claims 1-7.

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