Molten salt pipeline corrosion real-time monitoring method

Abstract

The invention relates to the field of fused salt pipeline corrosion monitoring, and provides a fused salt pipeline corrosion real-time monitoring method which comprises the following steps: acquiring a design drawing of a fused salt pipeline, and dividing a fused salt pipeline area in the design drawing into a plurality of grid areas by utilizing a Cartesian coordinate system; monitoring sensors are installed in the actual fused salt pipelines of all the grid areas, and pipeline data are collected in real time through the monitoring sensors; calculating the real-time corrosion rate of the actual fused salt pipeline in each grid region based on the electrochemical parameters and the pipeline data; a three-dimensional model of the actual fused salt pipeline is constructed, and the corrosion condition of the actual fused salt pipeline is simulated through the real-time corrosion rate and pipeline data; and calculating a risk level of each grid region based on a simulation result, determining a risk category of each grid region, and performing early warning on the grid regions with different risk categories in different modes. According to the method, the development trend and the distribution condition of molten salt pipeline corrosion can be displayed more visually and comprehensively, and graded management of pipeline corrosion risks is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of molten salt pipeline corrosion monitoring, and particularly relates to a real-time monitoring method for molten salt pipeline corrosion. Background Art

[0002] In many industrial fields such as energy and chemical industries, molten salt pipelines, as key facilities for transporting high-temperature molten salts, the stability and safety of their operation are of crucial importance. However, due to the characteristics of molten salts such as high temperature and strong corrosiveness, molten salt pipelines are extremely vulnerable to corrosion during long-term service, which may further lead to serious accidents such as leakage. This will not only cause production interruption and huge economic losses, but also pose a serious threat to personnel safety and the surrounding environment.

[0003] Currently, traditional molten salt pipeline corrosion monitoring methods have many limitations. On the one hand, many monitoring methods cannot achieve real-time and comprehensive monitoring. Regular manual inspections not only consume a large amount of manpower and time, but are also greatly affected by human factors, making it difficult to detect early subtle corrosion signs inside the pipeline and unable to detect potential safety hazards in a timely manner. On the other hand, some existing on-line monitoring technologies have deficiencies in the comprehensiveness and accuracy of data collection. Usually, only a single parameter such as temperature or pressure is monitored, making it difficult to accurately evaluate the corrosion status of the pipeline and unable to comprehensively consider the synergistic effects of multiple factors on corrosion. Moreover, for molten salt pipelines in different regions, their operating environments and working conditions usually vary, and the corrosion situations are also different. Therefore, traditional molten salt pipeline corrosion monitoring methods are difficult to conduct accurate analysis and evaluation for pipelines in each region. Summary of the Invention

[0004] The present invention aims to at least solve one of the problems existing in the prior art, and provides a real-time monitoring method for molten salt pipeline corrosion.

[0005] In one aspect of the present invention, a real-time monitoring method for molten salt pipeline corrosion is provided. The real-time monitoring method for molten salt pipeline corrosion includes: Step S1: Obtain the design drawing of the molten salt pipeline, and adaptively divide the molten salt pipeline area in the design drawing into a number of grid areas by using a Cartesian coordinate system; Step S2: Install monitoring sensors in the actual molten salt pipelines corresponding to each of the grid areas respectively, and use the monitoring sensors to collect molten salt pipeline data in real time. The molten salt pipeline data includes temperature data, flow rate data, and pressure data inside the actual molten salt pipeline; Step S3: Based on electrochemical parameters and the temperature data and flow rate data, calculate the real-time corrosion rate of the actual molten salt pipeline corresponding to each of the grid areas through the theory of electrochemical corrosion; Step S4: Construct a 3D model of the actual molten salt pipeline. Using the real-time corrosion rate and the molten salt pipeline data, based on the corrosion kinetics model and thermodynamics model corresponding to the 3D model, simulate the corrosion situation of the actual molten salt pipeline to obtain a simulation result; Step S5: Based on the simulation result, combining multiple molten salt pipeline corrosion factors, calculate the risk levels of the molten salt pipelines in each grid area respectively. Based on the risk levels corresponding to each grid area, determine the risk level threshold ranges corresponding to different risk categories. Based on the risk levels corresponding to each grid area, determine the risk categories of each grid area respectively. For each grid area with different risk categories, issue warnings through different warning methods and take corresponding targeted maintenance measures.

[0006] Preferably, step S1 specifically includes: Obtain the design drawing, use an edge detection algorithm to determine the edge of the molten salt pipeline area in the design drawing to obtain pipeline contour information; Select a point on the design drawing as the origin of the Cartesian coordinate system, and respectively specify the positive directions of the x-axis and y-axis in the Cartesian coordinate system; According to the pipeline contour information, calculate the minimum circumscribed rectangle of the molten salt pipeline area in the design drawing as the bounding box, and determine the initial grid size based on the size and complexity of the molten salt pipeline; Based on the initial grid size and the Cartesian coordinate system, divide the bounding box into several initial grids; For each initial grid, determine whether it intersects with the molten salt pipeline area. If so, further subdivide the corresponding initial grid; Continuously perform subdivision operations on the grids that still intersect with the molten salt pipeline area after subdivision until the maximum subdivision times are reached or the minimum grid size after subdivision is less than the preset size threshold.

[0007] Preferably, the monitoring sensors in step S2 include a temperature sensor, a flow rate sensor, and a pressure sensor.

[0008] Preferably, step S3 specifically includes: Calculate the real-time corrosion rate according to the following formula :

[0009] Where, is a constant, is the molar mass of the molten salt pipeline metal, is the number of electron transfers during the dissolution of the molten salt pipeline metal, is the density of the molten salt pipeline metal, is the corrosion current density and , is the Stern-Geary constant, is the polarization resistance.

[0010] Preferably, in the step S4, the constructing the three-dimensional model of the actual molten salt pipeline includes: Obtaining the design drawings, which include the orientation, layout, and horizontal and vertical orientations of the molten salt pipeline; Based on the design drawings, using 3D modeling software to build a basic model, draw the three-dimensional model of the actual molten salt pipeline, and add pipe fittings and auxiliary facilities to the three-dimensional model; Based on the pipeline material of the actual molten salt pipeline, select a suitable pipeline material in the material library of the 3D modeling software and add it to the three-dimensional model, and add the density, elastic modulus, and Poisson's ratio of the pipeline material to the three-dimensional model; Define the density, viscosity, specific heat capacity, and conductivity of the molten salt in the molten salt pipeline of the three-dimensional model, and add the starting time and corrosion rate distribution method to the three-dimensional model.

[0011] Preferably, in the step S4, the using the real-time corrosion rate and the molten salt pipeline data, based on the corrosion kinetics model and the thermodynamics model corresponding to the three-dimensional model, to simulate the corrosion situation of the actual molten salt pipeline to obtain a simulation result, including: Collect the pipeline material, size, and real-time corrosion rate of the actual molten salt pipeline, process and analyze to establish a database, and mine the correlation between the pipeline material, size, and real-time corrosion rate of the actual molten salt pipeline; Perform mesh division on the three-dimensional model, set the boundary and initial conditions, and determine and adjust the parameters of the three-dimensional model according to the database; Based on the three-dimensional model after mesh division, supported by the corrosion kinetics model and the thermodynamics model corresponding to the three-dimensional model, use the finite element solution method combined with Python programming to simulate the corrosion process of the actual molten salt pipeline, monitor the simulation calculation process, and obtain a visual simulation result.

[0012] Preferably, the based on the three-dimensional model after mesh division, supported by the corrosion kinetics model and the thermodynamics model corresponding to the three-dimensional model, using the finite element solution method combined with Python programming to simulate the corrosion process of the actual molten salt pipeline, monitor the simulation calculation process, and obtain a visual simulation result, including: Based on the corrosion kinetics model, simulate the corrosion reaction occurrence rate and corrosion process of the actual molten salt pipeline; Based on the thermodynamic model, determine whether the corrosion reaction of the actual molten salt pipeline can occur spontaneously and the reaction direction of the corrosion reaction; Based on the three-dimensional model, calculate the electrode potential according to the activity and standard electrode potential of substances in the electrode reaction of the actual molten salt pipeline, compare different electrode potentials, and clarify the possibility of the corrosion reaction occurring; In the process of iterative solution using the finite element solution method, calculate the residual corresponding to the three-dimensional model for each iterative solution. When the residual is less than the preset convergence threshold, stop the iterative solution to obtain the simulation result; wherein, during the simulation process, the substances and charges generated by the corrosion reaction maintain an equilibrium state in the entire system of the three-dimensional model; Using drawing software, plot the simulation result into a potential distribution contour map of the actual molten salt pipeline.

[0013] Preferably, in step S5, based on the simulation result, combining multiple corrosion factors of the molten salt pipeline, calculate the risk level of the molten salt pipeline in each grid area respectively, including: For each grid area, quantify and weight each corrosion factor of the molten salt pipeline to obtain the corresponding risk level; wherein, the multiple corrosion factors of the molten salt pipeline include the real-time corrosion rate, corrosion depth, environmental severity, and pipeline importance; The corrosion depth is measured based on non-destructive testing methods; The environmental severity is obtained by scoring the environmental severity of the real environment where the actual molten salt pipeline is located; The pipeline importance is obtained by evaluating the role and influence range of the actual molten salt pipeline in the pipeline transportation system.

[0014] Preferably, the quantification and weighting of each corrosion factor of the molten salt pipeline to obtain the risk level include: Calculate the risk level according to the following formula :

[0015] Wherein, is the real-time corrosion rate, and its value is mapped to between 0 and 1; is the corrosion depth; is the score of the environmental severity, with a value range of 1 - 5; is the score of the pipeline importance, with a value range of 1 - 5; , , , are respectively , , , weights, and .

[0016] Preferably, in the step S5, determining the risk level threshold ranges corresponding to different risk categories based on the risk levels corresponding to each grid region includes: Setting the risk level threshold range corresponding to the low - risk category as: ; Setting the risk level threshold range corresponding to the medium - risk category as: ; Setting the risk level threshold range corresponding to the high - risk category as: .

[0017] The real - time monitoring method for molten salt pipeline corrosion provided by the present invention divides the molten salt pipeline area in the design drawing into several grid regions adaptively according to the design drawing of the molten salt pipeline and the Cartesian coordinate system, installs monitoring sensors in the actual molten salt pipelines corresponding to each grid region respectively, uses the monitoring sensors to collect the temperature data, flow rate data, and pressure data in the actual molten salt pipeline in real - time, calculates the real - time corrosion rate of the actual molten salt pipeline corresponding to each grid region through the electrochemical corrosion theory according to the electrochemical parameters and the collected temperature data and flow rate data, constructs a three - dimensional model of the actual molten salt pipeline, uses the real - time corrosion rate and the data collected by the monitoring sensors in real - time, combines the corrosion kinetics model and the thermodynamics model corresponding to the three - dimensional model to simulate the corrosion situation of the actual molten salt pipeline, obtains the simulation result, based on the simulation result, combines multiple molten salt pipeline corrosion factors, calculates the risk level of the molten salt pipeline in each grid region respectively, determines the risk category of each grid region according to the risk level threshold range where the risk level corresponding to each grid region is located, and for each grid region with different risk categories, issues a warning through different warning methods and takes corresponding targeted maintenance measures. The real - time monitoring method for molten salt pipeline corrosion provided by the present invention can accurately locate each molten salt pipeline area, which is convenient for more accurately monitoring and analyzing the corrosion situation of the molten salt pipeline and avoiding missing some key parts; by simulating the corrosion situation of the molten salt pipeline based on the real - time corrosion rate, it can also more intuitively and comprehensively display the development trend and distribution of pipeline corrosion, help the staff deeply understand the corrosion mechanism, and provide a scientific basis for formulating reasonable protection strategies; it also realizes the hierarchical management of pipeline corrosion risks, so that maintenance resources can be reasonably allocated, and the areas with higher corrosion risk in the molten salt pipeline can be preferentially maintained. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the flowchart of the real - time monitoring method for molten salt pipeline corrosion provided by the present invention. Detailed implementation manners

[0019] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and other obvious variations can be conceived by those skilled in the art.

[0020] As Figure 1 shown, a real-time monitoring method for molten salt pipeline corrosion includes steps S1 to S5; Step S1: Obtain the design drawings of the molten salt pipeline, and use the Cartesian coordinate system to adaptively divide the molten salt pipeline area in the design drawings into several grid areas; Step S2: Install monitoring sensors in the actual molten salt pipelines corresponding to each grid area respectively, and use the monitoring sensors to collect molten salt pipeline data in real time. The molten salt pipeline data includes temperature data, flow rate data and pressure data in the actual molten salt pipeline; Step S3: Based on the electrochemical parameters, temperature data and flow rate data, calculate the real-time corrosion rate of the actual molten salt pipeline corresponding to each grid area through the electrochemical corrosion theory; Step S4: Construct a three-dimensional model of the actual molten salt pipeline, and use the real-time corrosion rate and the molten salt pipeline data to simulate the corrosion situation of the actual molten salt pipeline based on the corrosion kinetics model and the thermodynamics model corresponding to the three-dimensional model to obtain a simulation result; Step S5: Based on the simulation result, combined with multiple molten salt pipeline corrosion factors, calculate the risk levels of the molten salt pipelines in each grid area respectively. Based on the risk levels corresponding to each grid area, determine the risk level threshold ranges corresponding to different risk categories. Based on the risk levels corresponding to each grid area, determine the risk categories of each grid area respectively. For each grid area with different risk categories, issue warnings through different warning methods and take corresponding targeted maintenance measures.

[0021] The real-time monitoring method for molten salt pipeline corrosion provided by this embodiment can adaptively divide the molten salt pipeline area into several grid areas by obtaining the design drawings of the molten salt pipeline and performing grid division based on the Cartesian coordinate system, realizing refined management of the molten salt pipeline, so as to accurately locate each grid area corresponding to the actual molten salt pipeline, facilitating more accurate monitoring and analysis of the corrosion condition of the actual molten salt pipeline and avoiding missing some key parts; by installing monitoring sensors in the actual molten salt pipeline corresponding to each grid area, molten salt pipeline data including temperature data, flow rate data, and pressure data inside the actual molten salt pipeline can be collected in real time through the monitoring sensors; by calculating the real-time corrosion rate of the actual molten salt pipeline based on the electrochemical parameters, temperature data, and flow rate data, the operating state and corrosion condition of the actual molten salt pipeline can be timely reflected by this real-time corrosion rate. Once the data is abnormal, a quick response can be made, providing a strong basis for taking protective measures in a timely manner; by constructing a three-dimensional model of the actual molten salt pipeline and combining the corresponding corrosion kinetics model and thermodynamics model, and simulating the corrosion condition of the actual molten salt pipeline according to the real-time corrosion rate and molten salt pipeline data, the development trend and distribution of pipeline corrosion can be presented more intuitively and comprehensively, helping the staff to deeply understand the corrosion mechanism and providing a scientific basis for formulating reasonable protection strategies; by calculating the risk levels of the molten salt pipelines in each grid area respectively based on the simulation results combined with multiple molten salt pipeline corrosion factors and determining the risk categories corresponding to each grid area according to the corresponding risk level threshold ranges, different warning methods can be adopted for warning for grid areas with different risk categories, and corresponding targeted maintenance measures can be taken, thus realizing hierarchical management of pipeline corrosion risks, which can reasonably allocate maintenance resources, preferentially maintain the areas with higher corrosion occurrence risks in the molten salt pipeline, and improve the efficiency and economy of pipeline maintenance.

[0022] Generally speaking, the real-time monitoring method for molten salt pipeline corrosion provided by this embodiment can timely discover the corrosion problems of the actual molten salt pipeline through a series of measures such as real-time monitoring, simulation analysis, and risk classification and warning, and take effective preventive measures to avoid safety accidents such as pipeline leakage caused by corrosion, thus ensuring the safe and stable operation of the molten salt pipeline, reducing the safety risks in the production process. By timely understanding the corrosion condition of the molten salt pipeline and taking corresponding measures, it helps to slow down the corrosion rate of the molten salt pipeline, extend the service life of the molten salt pipeline, reduce the replacement and repair frequency of the molten salt pipeline, and thus reduce the operating costs of the enterprise.

[0023] Exemplarily, step S1 specifically includes: Obtain the design drawings of the molten salt pipeline, analyze the design drawings based on the image processing method, use the edge detection algorithm to determine the edge of the molten salt pipeline area in the design drawings, and obtain the pipeline contour information; Select a point on the design drawing as the origin of the Cartesian coordinate system, determine the axis directions, and respectively specify the positive directions of the x-axis and y-axis in the Cartesian coordinate system. For example, the positive direction of the x-axis is to the right, and the positive direction of the y-axis is upward. Based on the pipeline contour information, calculate the minimum bounding rectangle of the molten salt pipeline area in the design drawing as the bounding box, and determine the initial grid size based on the size and complexity of the molten salt pipeline. Based on the initial grid size and the Cartesian coordinate system, divide the entire bounding box into several initial grids. For each initial grid, determine whether it intersects with the molten salt pipeline area. If it does, further subdivide the corresponding initial grid; if not, keep the corresponding initial grid unchanged. Continuously perform subdivision operations on the grids that still intersect with the molten salt pipeline area after subdivision until the stop condition is met, that is, the maximum subdivision number is reached or the minimum grid size after subdivision is less than the preset size threshold.

[0024] Specifically, step S1 can also save the result of grid division as a data file, and record the coordinate information of each grid and the identifier of whether it intersects with the molten salt pipeline area in the data file; step S1 can also perform visualization processing on the result of grid division to intuitively view the division effect.

[0025] In this embodiment, by using the edge detection algorithm in image processing to obtain the pipeline contour information in the design drawing, determining the bounding box based on the pipeline contour information and performing grid division, the divided grids can accurately fit the actual shape of the molten salt pipeline, avoiding missing key information due to unreasonable grid division in the complex parts of the molten salt pipeline, and ensuring comprehensive and detailed monitoring of the molten salt pipeline. By clarifying the origin and axis directions of the Cartesian coordinate system, a unified and clear spatial positioning standard is established for each grid area, which helps to accurately associate the data of different grid areas in subsequent data acquisition, simulation analysis, and risk assessment processes, facilitating cross-regional comparison and comprehensive analysis, and improving the accuracy and systematicness of the entire monitoring process.

[0026] Exemplarily, the monitoring sensors in step S2 include a temperature sensor, a flow rate sensor, and a pressure sensor; step S2 deploys the temperature sensor, the flow rate sensor, and the pressure sensor in the actual molten salt pipeline corresponding to each grid area, and uses these sensors to collect molten salt pipeline data including temperature data, flow rate data, and pressure data. The collected molten salt pipeline data can be integrated into a pipeline data set after preprocessing.

[0027] In this embodiment, the temperature sensor, the flow rate sensor and the pressure sensor can work together to comprehensively collect the key parameters of the molten salt flowing in the actual molten salt pipeline, namely temperature data, flow rate data and pressure data. Among them, the temperature data can reflect the thermal environment inside the actual molten salt pipeline and is crucial for analyzing the influence of the corrosion reaction rate. The flow rate data helps to understand the flow state of the molten salt in the actual molten salt pipeline to determine whether there is erosion corrosion caused by abnormal flow rate. The pressure data can monitor the pressure conditions of the actual molten salt pipeline operation to prevent safety problems caused by too high pressure and indirectly affect the corrosion process.

[0028] Exemplarily, based on the Stern-Geary equation, the corrosion current density and the polarization resistance have the following relationship:

[0029] Wherein, is the corrosion current density, and the unit is . is the Stern-Geary constant. In the molten salt system, the value of can be determined by experiments. is the polarization resistance, and the unit is , which can be obtained by measuring the electrochemical impedance spectrum.

[0030] Based on the corrosion current density , step S3 specifically includes: According to the following formula, calculate the real-time corrosion rate :

[0031] Wherein, is the corrosion rate, and the unit is . is a constant. When the unit of the corrosion rate is , . is the molar mass of the molten salt pipeline metal, and the unit is . is the number of electron transfers during the dissolution of the molten salt pipeline metal. is the density of the molten salt pipeline metal, and the unit is .

[0032] In this embodiment, based on the corrosion current density, the characteristic parameters of the molten salt pipeline metal itself, namely molar mass, number of electron transfers, and density, are comprehensively considered. These characteristic parameters are introduced into the calculation formula of the real-time corrosion rate, enabling the calculation of the real-time corrosion rate to be closely combined with the properties of the molten salt pipeline metal, comprehensively reflecting the corrosion situation of the molten salt pipeline metal in the molten salt system, thus accurately obtaining the real-time corrosion rate, providing a quantitative index for evaluating the corrosion degree of the molten salt pipeline, and also providing an important decision-making basis for the maintenance and management of the molten salt pipeline. According to the magnitude of the real-time corrosion rate, the corrosion status of the molten salt pipeline can be judged in a timely manner.

[0033] Exemplarily, in step S4, constructing the three-dimensional model of the actual molten salt pipeline includes: Obtain the design drawings of the molten salt pipeline, which include the orientation, layout, and horizontal and vertical orientations of the molten salt pipeline; Based on the design drawings, use 3D modeling software to build the basic model, draw the three-dimensional model of the actual molten salt pipeline, and add pipe fittings and auxiliary facilities to the three-dimensional model; Based on the pipeline material of the actual molten salt pipeline, select the corresponding pipeline material in the material library of the 3D modeling software and add it to the three-dimensional model, and add the density, elastic modulus, and Poisson's ratio of the pipeline material to the three-dimensional model; Define the density, viscosity, specific heat capacity, and conductivity of the molten salt in the molten salt pipeline of the three-dimensional model, and add the start time and corrosion rate distribution method to the three-dimensional model.

[0034] In this embodiment, by obtaining the design drawings of the molten salt pipeline and establishing a 3D model of the actual molten salt pipeline based on the pipeline orientation, layout, horizontal and vertical orientations in the drawings, the actual shape of the molten salt pipeline can be highly restored. Whether it is complex bends, branches, or different laying directions, they can all be accurately presented in the 3D model, providing a reliable structural basis for subsequent analysis. By adding pipe fittings and auxiliary facilities to the 3D model, all key parts of the molten salt pipeline system can be included in the 3D model, forming a complete simulation object, thus making the subsequent corrosion process simulation analysis closer to the actual working conditions and avoiding result deviations caused by neglecting some facilities. By selecting appropriate pipeline materials from the material library of the 3D modeling software according to the pipeline materials of the actual molten salt pipeline and adding them to the 3D model, and adding the density, elastic modulus, and Poisson's ratio of the pipeline materials to the 3D model, the 3D model can accurately simulate the mechanical properties of the pipeline materials of the actual molten salt pipeline under different working conditions, such as stress deformation and stress distribution, providing a basis for evaluating the structural safety of the molten salt pipeline. By defining the properties of the molten salt, such as density, viscosity, specific heat capacity, and conductivity, in the molten salt pipeline of the 3D model, the 3D model can more realistically simulate the flow characteristics, heat transfer process, and electrochemical corrosion process of the molten salt in the actual molten salt pipeline, making the simulation results more accurately reflect the actual physical and chemical phenomena.

[0035] Exemplarily, in step S4, using the real-time corrosion rate and the molten salt pipeline data, based on the corrosion kinetics model and thermodynamics model corresponding to the 3D model, the corrosion situation of the actual molten salt pipeline is simulated to obtain simulation results, including: Collect the pipeline materials, dimensions, and real-time corrosion rate of the actual molten salt pipeline, process and analyze them to establish a database, and explore the correlation between the pipeline materials, dimensions, and real-time corrosion rate of the actual molten salt pipeline; Perform mesh division on the 3D model of the actual molten salt pipeline, set the boundaries and initial conditions, and determine and adjust the parameters of the 3D model according to the database; Based on the 3D model after mesh division, supported by the corrosion kinetics model and thermodynamics model corresponding to the 3D model, use the finite element solution method combined with Python programming to simulate the corrosion process of the actual molten salt pipeline, monitor the simulation calculation process, and obtain a visual simulation result to analyze the corrosion index through the visual simulation result.

[0036] In this embodiment, by collecting the pipe material, size, and real-time corrosion rate of the actual molten salt pipeline and establishing a database, information can be systematically integrated. By exploring the correlation between the pipe material, size, and real-time corrosion rate of the actual molten salt pipeline, the internal relationship between the pipe material characteristics, size specifications, and real-time corrosion rate of the actual molten salt pipeline can be discovered, and it can be determined under which size the actual molten salt pipeline of a specific material is more susceptible to corrosion, providing data support for pipeline selection, design, and maintenance, enabling relevant staff to formulate strategies based on objective data. By meshing the three-dimensional model of the actual molten salt pipeline, setting boundaries and initial conditions, and determining and adjusting the parameters of the three-dimensional model according to the database data, the corrosion process simulation environment of the actual molten salt pipeline can be highly close to the real working conditions, and the three-dimensional model of the actual molten salt pipeline can be more accurate, thus providing a reliable basis for finite element simulation and more accurately predicting the corrosion behavior of the molten salt pipeline under different working conditions, such as the corrosion evolution under extreme working conditions of high temperature and high pressure. By using the finite element solution method combined with Python programming to simulate the corrosion process of the actual molten salt pipeline, the rich library resources of Python can be used to efficiently process complex numerical calculations. By simulating the corrosion process of the actual molten salt pipeline under the support of the corrosion kinetics model and thermodynamics model corresponding to the three-dimensional model, the corrosion reaction rate and the microscopic process of the change in electrode potential of the actual molten salt pipeline can be deeply analyzed. By monitoring the simulation calculation process, the reliability of the results can be ensured, and calculation anomalies can be discovered and solved in a timely manner. The visual simulation results can also more intuitively present various corrosion indicators through intuitive graphics such as corrosion rate distribution cloud maps and potential change curves. Through intuitive graphics, staff can quickly locate the areas with higher corrosion risks of the actual molten salt pipeline, analyze the influence trends of different factors on corrosion, provide clear basis for formulating targeted protection measures, and improve work efficiency and decision-making science.

[0037] Exemplarily, based on the three-dimensional model after meshing, under the support of the corrosion kinetics model and thermodynamics model corresponding to the three-dimensional model, the finite element solution method is used in combination with Python programming to simulate the corrosion process of the actual molten salt pipeline, monitor the simulation calculation process, and obtain visual simulation results, including: Based on the corrosion kinetics model, simulate the occurrence rate and process of the corrosion reaction of the actual molten salt pipeline; based on the thermodynamics model, determine whether the corrosion reaction of the actual molten salt pipeline can occur spontaneously and the reaction direction of the corrosion reaction; based on the three-dimensional model, calculate the electrode potential according to the activity and standard electrode potential of substances in the electrode reaction of the actual molten salt pipeline, compare different electrode potentials, and clarify the possibility of the occurrence of the corrosion reaction; In the process of iterative solution using the finite element method, the residual corresponding to the three-dimensional model is calculated for each iterative solution. As the iterative solution progresses, the residual gradually decreases. When the residual is less than the preset convergence threshold, the iterative solution is stopped to obtain the simulation result. Among them, in the simulation process, that is, within the scope of corrosion simulation, it is necessary to ensure that the substances and charges generated by the corrosion reaction maintain a balanced state in the entire system of the three-dimensional model. Using drawing software, the simulation results are plotted into a potential distribution contour map of the actual molten salt pipeline to display the potential distribution in the actual molten salt pipeline through the potential distribution contour map, and comprehensively evaluate the corrosion risks in different regions of the actual molten salt pipeline.

[0038] Specifically, in the activation polarization model of the corrosion kinetics model, the rate of the metal anodic dissolution reaction is described by the Butler-Volmer equation. The Butler-Volmer equation is expressed as: the current density is equal to the exchange current density multiplied by the difference between two exponential terms. In the difference between the two exponential terms, the first exponential term is the exponential of the product of the anodic transfer coefficient, the number of reaction electrons, the Faraday constant, and the overpotential divided by the product of the gas constant and the absolute temperature, and the second exponential term is the exponential of the product of the cathodic transfer coefficient, the number of reaction electrons, the Faraday constant, and the overpotential divided by the product of the gas constant and the absolute temperature. The result obtained by subtracting the second exponential term from the first exponential term is the above-mentioned difference between the two exponential terms.

[0039] In the thermodynamic model, the Nernst equation is used to calculate the electrode potential. According to the Nernst equation, the electrode potential is equal to the sum of two parts. One part is the standard electrode potential, and the other part is the result of the product of the gas constant and the absolute temperature divided by the product of the number of reaction electrons and the Faraday constant, and then multiplied by the natural logarithm of the ratio of the activity of the oxidized substance to the activity of the reduced substance.

[0040] In the finite element discretization process, within each mesh element obtained by meshing the three-dimensional model, unknown variables such as potential and concentration can be obtained by interpolation using shape functions. Taking the potential as an example, the potential at a certain point within the mesh element is equal to the sum of the products of the shape functions of each node and the corresponding node potentials. The same applies to the concentration. The control equations are weighted and integrated over the mesh element to obtain the stiffness matrix and load vector of the element. The relevant matrices and load vectors of all elements are assembled to obtain the overall linear equations.

[0041] In numerical solution, by inverting the overall stiffness matrix and multiplying it by the overall load vector, the vector of unknown variables can be obtained.

[0042] During the monitoring of the simulation calculation process, for each iterative solution, the residuals corresponding to the three-dimensional model are calculated. The residuals are the norm of the product of the global stiffness matrix and the vector of unknown variables minus the global load vector. When the calculated residuals are less than the preset convergence threshold, it is considered that the calculation has converged, the iterative solution is stopped, and the corresponding simulation results are output.

[0043] In the calculation of the corrosion rate in the analysis of the simulation results, according to Faraday's law, the corrosion rate of the actual molten salt pipeline is equal to the product of the metal molar mass and the corrosion current density, divided by the product of the number of reaction electrons, the Faraday constant, and the metal density.

[0044] Exemplarily, in step S5, based on the simulation results and in combination with multiple molten salt pipeline corrosion factors, the risk levels of the molten salt pipelines in each grid area are calculated respectively, including: For each grid area, each molten salt pipeline corrosion factor is quantified and weighted to obtain the corresponding risk level; among them, the molten salt pipeline corrosion factors include real-time corrosion rate, corrosion depth, environmental severity, and pipeline importance; The corrosion depth is measured based on non-destructive testing methods; The environmental severity is obtained by scoring the environmental severity of the actual environment where the molten salt pipeline is located. The score range of the environmental severity is 1 - 5, and the higher the score, the more severe the environment; The pipeline importance is obtained by evaluating the role and influence range of the actual molten salt pipeline in the pipeline transportation system. For pipelines transporting key media and connecting important equipment, its importance is high; for auxiliary pipelines, its importance is low; the score range of the pipeline importance is 1 - 5, and the higher the score, the higher the pipeline importance.

[0045] Exemplarily, each molten salt pipeline corrosion factor is quantified and weighted to obtain the corresponding risk level, including: According to the following formula, the risk level is calculated :

[0046] Wherein, is the real-time corrosion rate, and its value is mapped to between 0 and 1; is the corrosion depth; is the score of the environmental severity, and the value range is 1 - 5; is the score of the pipeline importance, and the value range is 1 - 5; 、 、 、 are respectively 、 、 、 weights, and Each weight can be determined based on historical data.

[0047] Exemplarily, in step S5, based on the risk levels corresponding to each grid area, determine the range of risk level thresholds corresponding to different risk categories, including: Set the range of risk level thresholds corresponding to the low-risk category as: ; Set the range of risk level thresholds corresponding to the medium-risk category as: ; Set the range of risk level thresholds corresponding to the high-risk category as: .

[0048] For different risk categories, different warning methods can be set. For example, for the actual molten salt pipeline in the grid area with the low-risk category, regular prompts can be made through the internal management system of the power station. For the actual molten salt pipeline in the grid area with the medium-risk category, in addition to being prompted through the internal management system of the power station, a warning text message can also be sent to the operation and maintenance personnel. For the actual molten salt pipeline in the grid area with the high-risk category, an audible and visual alarm can be immediately triggered and prominently displayed on the large screen of the monitoring center.

[0049] For the actual molten salt pipelines belonging to different risk categories, different targeted maintenance measures can also be set. For example, for the actual molten salt pipeline belonging to the low-risk category, daily inspections can be strengthened. For the actual molten salt pipeline belonging to the medium-risk category, the inspection cycle can be shortened, and the anti-corrosion coating of the corroded part can be repaired. For the actual molten salt pipeline belonging to the high-risk category, shutdown maintenance can be immediately arranged to replace severely damaged pipeline components to ensure the safe and stable operation of the molten salt pipeline system.

[0050] After step S5 obtains the risk levels corresponding to each grid area, the risk category corresponding to the range of risk level thresholds where the risk levels corresponding to each grid area are located can be used as the risk category of each grid area. Based on the risk categories of each grid area, warnings can be issued through the warning methods corresponding to the respective risk categories, and targeted maintenance measures corresponding to the respective risk categories can be taken.

[0051] To enable those skilled in the art to better understand the above embodiments, a specific example is given below for illustration.

[0052] In a large-scale solar thermal power plant, molten salt pipelines serve as crucial heat transfer and energy storage carriers. Their safe and stable operation plays a decisive role in the efficient power generation of the power plant. Molten salt has strong corrosiveness in high-temperature environments, posing a severe challenge to the durability of pipelines. To effectively monitor the corrosion of molten salt pipelines, the power plant adopts a real-time monitoring method for molten salt pipeline corrosion, which encompasses a series of steps from grid division to risk response. The following elaborates on these steps in detail.

[0053] Grid Division: First, obtain the design drawings of the molten salt pipeline containing detailed design information, analyze the design drawings using professional image processing software, and accurately outline the edges of the molten salt pipeline area in the design drawings through edge detection algorithms to obtain pipeline contour information. Subsequently, take a fixed point at the starting end of the pipeline in the design drawings as the origin of the Cartesian coordinate system, stipulate that the positive direction of the x-axis in the Cartesian coordinate system is to the right and the positive direction of the y-axis is upward, establish a spatial coordinate system, calculate the minimum bounding rectangle of the molten salt pipeline area in the design drawings as the bounding box according to the pipeline contour information, and determine the initial grid size as 10 cm × 10 cm based on the complexity and actual size of the molten salt pipeline. Subsequently, divide the entire bounding box into numerous initial grids, and judge whether each initial grid intersects with the molten salt pipeline area one by one. For the initial grids that intersect with the molten salt pipeline area, further divide them into sub-grids of 5 cm × 5 cm; for the initial grids that do not intersect with the molten salt pipeline area, keep them unchanged, and continuously perform subdivision operations on the grids that still intersect with the molten salt pipeline area after subdivision until the maximum subdivision times of 10 times are reached and the minimum grid size after subdivision is less than the preset size threshold of 1 cm × 1 cm. Finally, save the grid division results as a data file, record the coordinate information of each grid and the identifier of whether it intersects with the molten salt pipeline area in this data file, and visually display the grid division effect through visualization software to lay a precise spatial positioning foundation for subsequent monitoring work.

[0054] Data acquisition: Temperature sensors, flow velocity sensors, and pressure sensors are respectively installed at the actual molten salt pipeline positions corresponding to each divided grid area. Among them, the temperature sensor uses a thermocouple-type sensor with high temperature resistance, which can accurately measure the temperature in the range of -200°C to 1300°C, and the accuracy reaches ±0.5°C. The flow velocity sensor selects an electromagnetic flowmeter, which can adapt to the flow velocity range of 0.1 m / s to 10 m / s, and the measurement error does not exceed ±1%. The pressure sensor is a high-precision strain gauge type pressure gauge, which can measure the pressure in the range of 0 MPa to 10 MPa, and the accuracy is ±0.2%FS. These sensors are used to collect the temperature data, flow velocity data, and pressure data in the actual molten salt pipeline in real time, and these data are sent to the data processing unit through a wireless transmission module. The data processing unit preprocesses the collected data, eliminates outliers and noise interference, and then integrates the processed data into a data set, updating the data every 10 minutes to ensure that the data in the data set can timely reflect the real-time state of the molten salt in the actual molten salt pipeline.

[0055] Calculation of real-time corrosion rate: Use an electrochemical workstation to measure the electrochemical parameters of the pipeline material, such as open circuit potential and polarization resistance. Based on the electrochemical parameters, combined with the temperature data and flow velocity data collected in real time, calculate the corrosion current density according to the Stern-Geary equation in the theory of electrochemical corrosion. In the molten salt system of this power station, the Stern-Geary constant is determined to be 25 mV through a large number of previous experiments. The polarization resistance is measured by electrochemical impedance spectroscopy. At a certain moment, when the polarization resistance of the pipeline corresponding to a certain grid area is 500 Ω·cm², the corrosion current density of this grid area is: . After obtaining the corrosion current density , use the formula to calculate the real-time corrosion rate , and the accurate calculation of the real-time corrosion rate of the actual molten salt pipeline corresponding to different grid areas can be realized.

[0056] Risk response: Using professional 3D modeling software, a high-precision 3D model of the actual molten salt pipeline was constructed based on the design drawings and actual installation data of the molten salt pipeline. The material properties of the pipeline are defined in detail in this 3D model, including the density, elastic modulus, and Poisson's ratio of the pipeline material. At the same time, the density, viscosity, specific heat capacity, and conductivity of the molten salt are accurately set. The calculated real-time corrosion rate of the actual molten salt pipeline is used as an input condition. Based on the corrosion kinetics model and thermodynamics model corresponding to the 3D model, the corrosion situation of the actual molten salt pipeline is simulated in 3D simulation software. During the simulation process, the influence of temperature, flow rate, and pressure on corrosion is fully considered. The finite element solution method is combined with Python programming, and through iterative calculations, the corrosion states of the actual molten salt pipeline at different time nodes are simulated, and the corresponding simulation results are obtained, such as the formation and expansion of corrosion pits and the change of pipeline wall thickness. Through simulation analysis, the corrosion development trends in different regions of the pipeline are clearly presented, providing an intuitive and reliable basis for subsequent risk assessment.

[0057] Risk response: Based on the comprehensive simulation results, considering multiple corrosion factors of the actual molten salt pipeline, including pipeline material, real-time corrosion rate, the environment it is in, especially the severity of the environment, and the importance of the pipeline, i.e., the importance of the actual molten salt pipeline in the power station system, the risk levels of the molten salt pipelines in each grid area are calculated respectively. , the risk level The calculation formula is , where is the normalized value of the real-time corrosion rate, is the normalized value of the corrosion depth, is the score of the environmental severity, is the score of the pipeline importance, , , , are respectively , , , The weights of are determined by expert evaluation , , , , according to the calculation results of the risk levels corresponding to each grid area, the risk categories and the corresponding risk level threshold ranges are determined as: low risk , medium risk , high risk When giving early warnings through the early warning methods corresponding to the respective risk categories, for the actual molten salt pipelines in the grid areas with a low-risk category, regular reminders are sent through the internal management system of the power station. For the actual molten salt pipelines in the grid areas with a medium-risk category, in addition to sending reminders through the internal management system of the power station, early warning text messages are also sent to the operation and maintenance personnel. For the actual molten salt pipelines in the grid areas with a high-risk category, an audible and visual alarm is immediately triggered and prominently displayed on the large screen in the monitoring center. When taking the targeted maintenance measures corresponding to the respective risk categories, for the actual molten salt pipelines belonging to the low-risk category, daily inspections are strengthened. For the actual molten salt pipelines belonging to the medium-risk category, the inspection cycle is shortened, and the anti-corrosion coating of the corroded parts is repaired. For the actual molten salt pipelines belonging to the high-risk category, shutdown maintenance is immediately arranged, and the severely damaged pipeline components are replaced to ensure the safe and stable operation of the molten salt pipeline system.

[0058] By implementing the above real-time monitoring method for molten salt pipeline corrosion, the solar thermal power station effectively improves its monitoring and prevention and control capabilities for molten salt pipeline corrosion, can timely detect and handle potential corrosion problems, reduces the number of shutdowns and maintenance costs caused by pipeline corrosion, and ensures the efficient and stable power generation of the power station.

[0059] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A real-time monitoring method for molten salt pipeline corrosion, characterized in that, The real-time monitoring method for molten salt pipeline corrosion includes: Step S1: Obtain the design drawing of the molten salt pipeline, and use the Cartesian coordinate system to adaptively divide the molten salt pipeline area in the design drawing into several grid areas; Step S2: Install monitoring sensors in the actual molten salt pipelines corresponding to each grid area respectively, and use the monitoring sensors to collect molten salt pipeline data in real time. The molten salt pipeline data includes temperature data, flow rate data, and pressure data in the actual molten salt pipeline; Step S3: Based on the electrochemical parameters, the temperature data, and the flow rate data, calculate the real-time corrosion rate of the actual molten salt pipeline corresponding to each grid area through the electrochemical corrosion theory; Step S4: Construct a three-dimensional model of the actual molten salt pipeline, and use the real-time corrosion rate and the molten salt pipeline data to simulate the corrosion situation of the actual molten salt pipeline based on the corrosion kinetics model and the thermodynamics model corresponding to the three-dimensional model, and obtain a simulation result; Step S5: Based on the simulation result, combined with multiple molten salt pipeline corrosion factors, calculate the risk levels of the molten salt pipelines in each grid area respectively. Based on the risk levels corresponding to each grid area, determine the risk level threshold ranges corresponding to different risk categories. Based on the risk levels corresponding to each grid area, determine the risk categories of each grid area respectively. For each grid area with different risk categories, issue a warning through different warning methods and take corresponding targeted maintenance measures.

2. The real-time monitoring method for molten salt pipeline corrosion according to claim 1, wherein The specific content of step S1 includes: Obtain the design drawing, and use an edge detection algorithm to determine the edge of the molten salt pipeline area in the design drawing to obtain pipeline contour information; Select a point on the design drawing as the origin of the Cartesian coordinate system, and respectively specify the positive directions of the x-axis and the y-axis in the Cartesian coordinate system; According to the pipeline contour information, calculate the minimum circumscribed rectangle of the molten salt pipeline area in the design drawing as the bounding box, and determine the initial grid size based on the size and complexity of the molten salt pipeline; Based on the initial grid size and the Cartesian coordinate system, divide the bounding box into several initial grids; For each initial grid, determine whether it intersects with the molten salt pipeline area. If so, further subdivide the corresponding initial grid; Continuously perform the subdivision operation on the grids that still intersect with the molten salt pipeline area after subdivision until the maximum subdivision times are reached or the minimum grid size after subdivision is smaller than the preset size threshold.

3. The real-time monitoring method for molten salt pipeline corrosion according to claim 1, characterized in that, The monitoring sensors in step S2 include a temperature sensor, a flow rate sensor, and a pressure sensor.

4. The real-time monitoring method for molten salt pipeline corrosion according to claim 1, wherein The specific content of step S3 includes: Calculate the real-time corrosion rate according to the following formula : Among them, is a constant, is the molar mass of the molten salt pipeline metal, is the number of electron transfers during the dissolution of the molten salt pipeline metal, is the density of the molten salt pipeline metal, is the corrosion current density and , is the Stern-Geary constant, is the polarization resistance.

5. The real-time monitoring method for molten salt pipeline corrosion according to claim 1, characterized in that In step S4, the construction of the three-dimensional model of the actual molten salt pipeline includes: Obtain the design drawing, which includes the direction, layout, and horizontal and vertical directions of the molten salt pipeline; Based on the design drawing, use 3D modeling software to build a basic model, draw the three-dimensional model of the actual molten salt pipeline, and add pipe fittings and auxiliary facilities to the three-dimensional model; Based on the pipeline material of the actual molten salt pipeline, select a suitable pipeline material from the material library of the 3D modeling software and add it to the 3D model, and add the density, elastic modulus and Poisson's ratio of the pipeline material to the 3D model; Define the density, viscosity, specific heat capacity and conductivity of the molten salt in the molten salt pipeline of the 3D model, and add the starting time and corrosion rate distribution method to the 3D model.

6. The real-time monitoring method for molten salt pipeline corrosion according to claim 1, characterized in that In step S4, using the real-time corrosion rate and the molten salt pipeline data, based on the corrosion kinetics model and thermodynamics model corresponding to the 3D model, simulate the corrosion situation of the actual molten salt pipeline to obtain simulation results, including: Collect the pipeline material, size and the real-time corrosion rate of the actual molten salt pipeline, process and analyze to establish a database, and mine the correlation between the pipeline material, size and the real-time corrosion rate of the actual molten salt pipeline; Perform mesh division on the 3D model, set the boundary and initial conditions, and determine and adjust the parameters of the 3D model according to the database; Based on the 3D model after mesh division, supported by the corrosion kinetics model and the thermodynamics model corresponding to the 3D model, use the finite element solution method combined with Python programming to simulate the corrosion process of the actual molten salt pipeline, monitor the simulation calculation process, and obtain a visual simulation result.

7. The real-time monitoring method for molten salt pipeline corrosion according to claim 6, wherein Based on the 3D model after mesh division, supported by the corrosion kinetics model and the thermodynamics model corresponding to the 3D model, use the finite element solution method combined with Python programming to simulate the corrosion process of the actual molten salt pipeline, monitor the simulation calculation process, and obtain a visual simulation result, including: Based on the corrosion kinetics model, simulate the corrosion reaction occurrence rate and corrosion process of the actual molten salt pipeline; Based on the thermodynamics model, determine whether the corrosion reaction of the actual molten salt pipeline can occur spontaneously and the reaction direction of the corrosion reaction; Based on the 3D model, calculate the electrode potential according to the activity and standard electrode potential of substances in the electrode reaction of the actual molten salt pipeline, compare different electrode potentials, and clarify the possibility of the corrosion reaction occurring; In the process of using the finite element solution method for iterative solution, calculate the residual corresponding to the 3D model for each iterative solution. When the residual is less than the preset convergence threshold, stop the iterative solution to obtain the simulation result; among them, during the simulation process, the substances and charges generated by the corrosion reaction maintain an equilibrium state in the entire system of the 3D model; Use drawing software to draw the simulation result into the potential distribution cloud map of the actual molten salt pipeline.

8. The real-time monitoring method for molten salt pipeline corrosion according to claim 1, characterized in that In step S5, based on the simulation result, combined with multiple molten salt pipeline corrosion factors, calculate the risk level of the molten salt pipeline in each grid area respectively, including: For each grid area, quantify and weight each molten salt pipeline corrosion factor to obtain the corresponding risk level; among them, the multiple molten salt pipeline corrosion factors include the real-time corrosion rate, corrosion depth, environmental severity, and pipeline importance; The corrosion depth is measured based on a non-destructive testing method; The severity of the environment is obtained by scoring the severity of the actual environment where the molten salt pipeline is located; The importance of the pipeline is obtained by evaluating the role and influence range of the actual molten salt pipeline in the pipeline transportation system.

9. The real-time monitoring method for molten salt pipeline corrosion according to claim 8, characterized in that, Quantifying and weighting the corrosion factors of each molten salt pipeline to obtain a risk level, including: Calculate the risk level according to the following formula :[[]]END]] Among them, is the real-time corrosion rate, and its value is mapped between 0 and 1; is the corrosion depth; is the score of the environmental severity, and the value range is 1 - 5; is the score of the pipeline importance, and the value range is 1 - 5; , , , are respectively , , , 's weights, and .

10. The real-time monitoring method for molten salt pipeline corrosion according to claim 9, characterized in that In step S5, based on the risk levels corresponding to each grid area, determining the risk level threshold ranges corresponding to different risk categories, including: Set the risk level threshold range corresponding to the low risk category of risks as: ; Set the risk level threshold range corresponding to the risk in the risk category to be: ; Set the risk level threshold range corresponding to the high-risk category of risks to be: .

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