A real-time monitoring method for molten salt pipeline corrosion

Abstract

The present invention relates to the field of molten salt pipeline corrosion monitoring and provides a real-time monitoring method for molten salt pipeline corrosion, comprising: obtaining a design drawing of the molten salt pipeline, dividing the molten salt pipeline area in the design drawing into a plurality of grid areas using a Cartesian coordinate system; installing monitoring sensors in the actual molten salt pipeline in each grid area, and using the monitoring sensors to collect pipeline data in real time; calculating the real-time corrosion rate of the actual molten salt pipeline in each grid area based on electrochemical parameters and pipeline data; constructing a three-dimensional model of the actual molten salt pipeline, and simulating the corrosion situation of the actual molten salt pipeline using the real-time corrosion rate and pipeline data; calculating the risk level of each grid area based on the simulation results, determining the risk category of each grid area, and issuing early warnings in different ways for grid areas with different risk categories. The present invention can more intuitively and comprehensively display the development trend and distribution of molten salt pipeline corrosion, thereby realizing hierarchical management of pipeline corrosion risks.

Description

Technical Field

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

[0002] In numerous industrial sectors, such as energy and chemicals, molten salt pipelines are critical infrastructure for transporting high-temperature molten salt, making their operational stability and safety crucial. However, due to the high temperature and highly corrosive nature of molten salt, molten salt pipelines are highly susceptible to corrosion over long periods of service, leading to serious accidents such as leaks. These not only disrupt production and cause significant economic losses, but can also pose serious threats 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 lot of manpower and time, but are also greatly affected by human factors. It is difficult to detect early signs of subtle corrosion inside the pipeline and potential safety hazards cannot be detected in time. On the other hand, some existing online monitoring technologies are insufficient in the comprehensiveness and accuracy of data collection. They usually only monitor a single parameter such as temperature or pressure, making it difficult to accurately assess the corrosion status of the pipeline and unable to comprehensively consider the synergistic effects of multiple factors on corrosion. In addition, for molten salt pipelines in different regions, their environments and working conditions are usually different, and the corrosion conditions are also different. Therefore, traditional molten salt pipeline corrosion monitoring methods are difficult to accurately analyze and evaluate pipelines in various regions. Summary of the Invention

[0004] The present invention aims to solve at least 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 method for real-time monitoring of molten salt pipeline corrosion is provided, comprising:

[0006] Step S1: obtaining a design drawing of a molten salt pipeline, and using a Cartesian coordinate system, adaptively dividing the molten salt pipeline area in the design drawing into a plurality of grid areas;

[0007] Step S2: installing monitoring sensors in the actual molten salt pipelines corresponding to the grid areas, respectively, and using the monitoring sensors to collect molten salt pipeline data in real time, the molten salt pipeline data including temperature data, flow rate data, and pressure data in the actual molten salt pipelines;

[0008] Step S3, calculating the real-time corrosion rate of the actual molten salt pipeline corresponding to each grid area using electrochemical corrosion theory based on the electrochemical parameters and the temperature data and the flow rate data;

[0009] Step S4: constructing a three-dimensional model of the actual molten salt pipeline, and using the real-time corrosion rate and the molten salt pipeline data, simulating the corrosion of the actual molten salt pipeline based on a corrosion kinetics model and a thermodynamic model corresponding to the three-dimensional model to obtain a simulation result;

[0010] Step S5: Based on the simulation results and in combination with multiple molten salt pipeline corrosion factors, the risk level of the molten salt pipeline in each grid area is calculated respectively; based on the risk level corresponding to each grid area, the risk level threshold range corresponding to different risk categories is determined; based on the risk level corresponding to each grid area, the risk category of each grid area is determined respectively; for each grid area with different risk categories, different early warning methods are used to issue early warnings, and corresponding targeted maintenance measures are taken.

[0011] Preferably, the step S1 specifically includes:

[0012] Obtaining the design drawing, and using an edge detection algorithm to determine the edge of the molten salt pipeline area in the design drawing to obtain pipeline contour information;

[0013] Selecting a point on the design drawing as the origin of the Cartesian coordinate system, and specifying the positive direction of the x-axis and the positive direction of the y-axis in the Cartesian coordinate system;

[0014] Based on the pipeline contour information, a minimum circumscribed rectangle of the molten salt pipeline area in the design drawing is calculated as a bounding box, and an initial grid size is determined based on the size and complexity of the molten salt pipeline;

[0015] Dividing the bounding box into a plurality of initial grids based on the initial grid size and the Cartesian coordinate system;

[0016] For each of the initial grids, determining whether it intersects with the molten salt pipeline area, and if so, further subdividing the corresponding initial grid;

[0017] The subdivision operation is continued on the grids obtained after subdivision and still intersecting with the molten salt pipeline area until a maximum number of subdivisions is reached or the minimum grid size after subdivision is smaller than a preset size threshold.

[0018] Preferably, the monitoring sensors in step S2 include a temperature sensor, a flow rate sensor and a pressure sensor.

[0019] Preferably, the step S3 specifically includes:

[0020] According to the following formula, the real-time corrosion rate is calculated :

[0021]

[0022] in, is a constant, is the molar mass of the molten salt pipe metal, is the number of electron transfers when the metal in the molten salt pipe dissolves, is the density of the molten salt pipe metal, is the corrosion current density and , is the Stern-Geary constant, is the polarization resistance.

[0023] Preferably, in step S4, constructing the three-dimensional model of the actual molten salt pipeline includes:

[0024] Obtaining the design drawings, which include the direction, layout, and horizontal and vertical directions of the molten salt pipeline;

[0025] Based on the design drawings, a basic model is constructed using 3D modeling software to draw the 3D model of the actual molten salt pipeline, and pipe fittings and ancillary facilities are added to the 3D model;

[0026] Based on the pipe material of the actual molten salt pipe, selecting a suitable pipe material from the material library of the 3D modeling software and adding it to the 3D model, and adding the density, elastic modulus and Poisson's ratio of the pipe material to the 3D model;

[0027] The density, viscosity, specific heat capacity and electrical conductivity of the molten salt are defined in the molten salt pipeline of the three-dimensional model, and the start time and corrosion rate distribution are added to the three-dimensional model.

[0028] Preferably, in step S4, the use of the real-time corrosion rate and the molten salt pipeline data to simulate the actual corrosion condition of the molten salt pipeline based on the corrosion kinetics model and thermodynamics model corresponding to the three-dimensional model to obtain a simulation result includes:

[0029] Collecting the pipe material, size and real-time corrosion rate of the actual molten salt pipe, processing and analyzing to establish a database, and mining the correlation between the pipe material, size and real-time corrosion rate of the actual molten salt pipe;

[0030] Meshing the three-dimensional model, setting boundaries and initial conditions, and determining and adjusting parameters of the three-dimensional model based on the database;

[0031] Based on the meshed three-dimensional model, supported by the corrosion kinetics model and the thermodynamics model corresponding to the three-dimensional model, the finite element solution method combined with Python programming is used to simulate the corrosion process of the actual molten salt pipeline, monitor the simulation calculation process, and obtain visual simulation results.

[0032] Preferably, the three-dimensional model after meshing is used, with the support of the corrosion kinetics model and the thermodynamic model corresponding to the three-dimensional model, to simulate the corrosion process of the actual molten salt pipeline using a finite element solution method combined with Python programming, monitor the simulation calculation process, and obtain visual simulation results, including:

[0033] Based on the corrosion kinetics model, simulating the corrosion reaction rate and corrosion process of the actual molten salt pipeline;

[0034] Based on the thermodynamic model, determining whether the corrosion reaction of the actual molten salt pipeline can proceed spontaneously and the reaction direction of the corrosion reaction;

[0035] Based on the three-dimensional model, the electrode potential is calculated according to the activity of the substances in the electrode reaction of the actual molten salt pipeline and the standard electrode potential, and different electrode potentials are compared to determine the possibility of the corrosion reaction;

[0036] During the iterative solution process using the finite element solution method, a residual corresponding to the three-dimensional model is calculated for each iterative solution. When the residual is less than a preset convergence threshold, the iterative solution is stopped to obtain the simulation result. During the simulation process, the substances and charges generated by the corrosion reaction maintain a state of equilibrium in the entire system of the three-dimensional model.

[0037] The simulation results are plotted into a potential distribution cloud diagram of the actual molten salt pipeline using drawing software.

[0038] Preferably, in step S5, the risk level of the molten salt pipeline in each grid area is calculated based on the simulation results and in combination with multiple molten salt pipeline corrosion factors, including:

[0039] For each grid area, each molten salt pipeline corrosion factor is quantified and weighted to obtain the corresponding risk level; wherein the multiple molten salt pipeline corrosion factors include the real-time corrosion rate, corrosion depth, environmental severity, and pipeline importance;

[0040] The corrosion depth is measured based on a non-destructive testing method;

[0041] The environmental severity is obtained by scoring the environmental severity of the actual environment in which the actual molten salt pipeline is located;

[0042] The pipeline importance is obtained by evaluating the role and impact range of the actual molten salt pipeline in the pipeline transportation system.

[0043] Preferably, the quantification and weighting of each of the molten salt pipeline corrosion factors to obtain a risk level includes:

[0044] Calculate the risk level according to the following formula: :

[0045]

[0046] in, is the real-time corrosion rate, whose value is mapped between 0 and 1; is the corrosion depth; is the score of the severity of the environment, ranging from 1 to 5; is the score of pipeline importance, ranging from 1 to 5;

[0047] 、 、 、 They are 、 、 、 The weight of .

[0048] Preferably, in step S5, determining the risk level threshold ranges corresponding to different risk categories based on the risk level corresponding to each grid area includes:

[0049] The risk level threshold range corresponding to the risk category low risk is set to: ;

[0050] The risk level threshold range corresponding to the risk in the risk category is set to: ;

[0051] The risk level threshold range corresponding to the high risk risk category is set to: .

[0052] The present invention provides a real-time monitoring method for molten salt pipeline corrosion. The method adaptively divides a molten salt pipeline area in the design drawing into a plurality of grid areas based on a design drawing of the molten salt pipeline and a Cartesian coordinate system. Monitoring sensors are installed in the actual molten salt pipeline corresponding to each grid area. The monitoring sensors are used to collect temperature data, flow rate data, and pressure data in the actual molten salt pipeline in real time. The real-time corrosion rate of the actual molten salt pipeline corresponding to each grid area is calculated based on electrochemical parameters and the collected temperature data and flow rate data using electrochemical corrosion theory. A three-dimensional model of the actual molten salt pipeline is constructed. The real-time corrosion rate and the data collected in real time by the monitoring sensors are combined with a corrosion kinetics model and a thermodynamic model corresponding to the three-dimensional model to simulate the corrosion of the actual molten salt pipeline to obtain simulation results. Based on the simulation results and in combination with multiple molten salt pipeline corrosion factors, the risk level of the molten salt pipeline in each grid area is calculated. The risk category of each grid area is determined based on the risk level threshold range of the risk level corresponding to each grid area. Different warning methods are used to issue warnings for grid areas of different risk categories, and corresponding targeted maintenance measures are taken. The real-time monitoring method for molten salt pipeline corrosion provided by the present invention can accurately locate each molten salt pipeline area, facilitating more accurate monitoring and analysis of the corrosion situation of the molten salt pipeline and avoiding missing certain 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, helping staff to 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 priority maintenance is given to areas with higher corrosion risks in the molten salt pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a flow chart of the real-time monitoring method for molten salt pipeline corrosion provided by the present invention. DETAILED DESCRIPTION

[0054] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art may conceive of other obvious variations.

[0055] like Figure 1 As shown, a real-time monitoring method for molten salt pipeline corrosion includes steps S1 to S5;

[0056] Step S1: obtaining a design drawing of a molten salt pipeline, and using a Cartesian coordinate system, adaptively dividing the molten salt pipeline area in the design drawing into a plurality of grid areas;

[0057] Step S2: installing monitoring sensors in the actual molten salt pipeline corresponding to each grid area, and using the monitoring sensors to collect molten salt pipeline data in real time, the molten salt pipeline data including temperature data, flow rate data, and pressure data in the actual molten salt pipeline;

[0058] Step S3: Based on the electrochemical parameters, temperature data, and flow rate data, the real-time corrosion rate of the actual molten salt pipeline corresponding to each grid area is calculated using electrochemical corrosion theory;

[0059] Step S4: constructing a three-dimensional 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 thermodynamic model corresponding to the three-dimensional model, simulating the corrosion condition of the actual molten salt pipeline to obtain simulation results;

[0060] Step S5: Based on the simulation results and in combination with multiple molten salt pipeline corrosion factors, the risk level of the molten salt pipeline in each grid area is calculated respectively. Based on the risk level corresponding to each grid area, the risk level threshold range corresponding to different risk categories is determined. Based on the risk level corresponding to each grid area, the risk category of each grid area is determined respectively. For each grid area with different risk categories, different early warning methods are used to issue early warnings, and corresponding targeted maintenance measures are taken.

[0061] The real-time monitoring method for molten salt pipeline corrosion provided by the present 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, thereby realizing refined management of the molten salt pipeline, so that each grid area corresponding to the actual molten salt pipeline can be accurately located, so as to facilitate more accurate monitoring and analysis of the corrosion situation of the actual molten salt pipeline and avoid missing certain key parts; by installing monitoring sensors in the actual molten salt pipeline corresponding to each grid area, the molten salt pipeline data including temperature data, flow rate data and pressure data in 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 electrochemical parameters, temperature data and flow rate data, the real-time corrosion rate can timely reflect the operating status and corrosion situation of the actual molten salt pipeline, and once the data is abnormal, a rapid response can be made to provide timely protection measures. Strong basis; by constructing a three-dimensional model of the actual molten salt pipeline, and combining it with the corresponding corrosion kinetic model and thermodynamic model, the corrosion situation of the actual molten salt pipeline is simulated according to the real-time corrosion rate and molten salt pipeline data, which can more intuitively and comprehensively display the development trend and distribution of pipeline corrosion, help staff to deeply understand the corrosion mechanism, and provide a scientific basis for formulating reasonable protection strategies; by combining multiple molten salt pipeline corrosion factors based on the simulation results, the risk level of the molten salt pipeline in each grid area is calculated respectively, and the risk category corresponding to each grid area is determined according to the corresponding risk level threshold range. Different early warning methods can be adopted for grid areas of different risk categories, and corresponding targeted maintenance measures can be taken, thereby realizing the hierarchical management of pipeline corrosion risks. In this way, maintenance resources can be reasonably allocated, priority can be given to maintaining areas with higher corrosion risks in the molten salt pipeline, and the efficiency and economy of pipeline maintenance can be improved.

[0062] In general, the real-time monitoring method for molten salt pipeline corrosion provided in this embodiment can timely discover the corrosion problems of actual molten salt pipelines through a series of measures such as real-time monitoring, simulation analysis and risk classification warning, and take effective preventive measures to avoid leakage safety accidents caused by pipeline corrosion, thereby ensuring the safe and stable operation of the molten salt pipeline and reducing safety risks in the production process. By timely understanding the corrosion status 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 maintenance frequency of the molten salt pipeline, and thus reduce the operating costs of the enterprise.

[0063] Exemplarily, step S1 specifically includes:

[0064] Obtaining a design drawing of the molten salt pipeline, analyzing the design drawing based on an image processing method, and using an edge detection algorithm to determine the edges of the molten salt pipeline area in the design drawing to obtain pipeline contour information;

[0065] Select a point on the design drawing as the origin of the Cartesian coordinate system, determine the direction of the coordinate axis, and specify the positive direction of the x-axis and the positive direction of the y-axis in the Cartesian coordinate system, such as the x-axis is positive to the right and the y-axis is positive upward;

[0066] Based on the pipeline outline information, the minimum enclosing rectangle of the molten salt pipeline area in the design drawing is calculated as the bounding box. The initial grid size is determined based on the size and complexity of the molten salt pipeline.

[0067] Based on the initial grid size and Cartesian coordinate system, the entire bounding box is divided into several initial grids;

[0068] For each initial grid, determine whether it intersects with the molten salt pipeline area. If so, further subdivide the corresponding initial grid; if not, keep the corresponding initial grid unchanged;

[0069] The subdivision operation is continued on the grids that still intersect with the molten salt pipeline area after subdivision until the stopping condition is met, that is, the maximum number of subdivisions is reached or the minimum grid size after subdivision is smaller than the preset size threshold.

[0070] In particular, step S1 can also save the grid division result as a data file, in which the coordinate information of each grid and the identification of whether it intersects with the molten salt pipeline area are recorded; step S1 can also visualize the grid division result to intuitively view the division effect.

[0071] This implementation utilizes edge detection algorithms in image processing to obtain pipeline outline information from design drawings. Based on this information, a bounding box is determined and meshed. This ensures that the resulting mesh accurately matches the actual shape of the molten salt pipeline, avoiding the omission of key information due to irrational meshing in complex areas of the pipeline, thereby ensuring comprehensive and detailed monitoring of the pipeline. By clarifying the Cartesian coordinate system's origin and axis directions, a unified and clear spatial positioning standard is established for each grid area. This helps accurately correlate data from different grid areas during subsequent data collection, simulation analysis, and risk assessment, facilitating cross-regional comparison and comprehensive analysis, and improving the accuracy and systematicness of the entire monitoring process.

[0072] Exemplarily, the monitoring sensors in step S2 include temperature sensors, flow rate sensors, and pressure sensors; step S2 deploys the temperature sensors, flow rate sensors, and pressure sensors in the actual molten salt pipelines 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.

[0073] In this embodiment, the temperature sensor, flow rate sensor, and pressure sensor work together to comprehensively collect key parameters of the molten salt flowing within an actual molten salt pipeline, namely temperature, flow rate, and pressure data. Temperature data reflects the thermal environment within the actual molten salt pipeline and is crucial for analyzing its impact on corrosion reaction rates. Flow rate data helps understand the flow state of the molten salt within the actual molten salt pipeline and determine whether erosion corrosion is occurring due to abnormal flow rates. Pressure data monitors the pressure conditions under which the actual molten salt pipeline operates, preventing safety issues caused by excessive pressure and indirect impacts on the corrosion process.

[0074] For example, based on the Stern-Geyre equation, the corrosion current density and polarization resistance The following relationship exists:

[0075]

[0076] in, is the corrosion current density, in units of . is the Stern-Geary constant, which can be determined experimentally in molten salt systems. The value of . is the polarization resistance, in units of , which can be measured by electrochemical impedance spectroscopy.

[0077] The corrosion current density On the basis of, step S3 specifically includes:

[0078] According to the following formula, the real-time corrosion rate is calculated :

[0079]

[0080] in, is the corrosion rate, in units of . is a constant, and the unit of corrosion rate is hour, . is the molar mass of the molten salt pipe metal, in units of . is the number of electrons transferred when the metal in the molten salt pipe dissolves. is the density of the molten salt pipe metal, in units of .

[0081] This embodiment comprehensively considers the characteristic parameters of the molten salt pipeline metal itself, namely molar mass, electron transfer number and density, on the basis of corrosion current density, and introduces these characteristic parameters into the calculation formula of the real-time corrosion rate. Therefore, the calculation of the real-time corrosion rate can 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, thereby accurately deriving the real-time corrosion rate, providing a quantitative indicator 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.

[0082] Exemplarily, in step S4, constructing a three-dimensional model of the actual molten salt pipeline includes:

[0083] Obtain design drawings of the molten salt pipeline, including the direction, layout, and horizontal and vertical directions of the molten salt pipeline;

[0084] Based on the design drawings, use 3D modeling software to build a basic model, draw a 3D model of the actual molten salt pipeline, and add pipe fittings and ancillary facilities to the 3D model;

[0085] Based on the actual molten salt pipeline material, select the appropriate pipeline material from the material library of the 3D modeling software and add it to the 3D model. Also, add the density, elastic modulus, and Poisson's ratio of the pipeline material to the 3D model.

[0086] The density, viscosity, specific heat capacity, and conductivity of the molten salt are defined in the 3D model of the molten salt pipeline, and the start time and corrosion rate distribution are added to the 3D model.

[0087] This embodiment obtains the design drawings of the molten salt pipeline and establishes a three-dimensional model of the actual molten salt pipeline based on the direction, layout, horizontal and vertical directions of the molten salt pipeline. The actual shape of the molten salt pipeline can be highly restored. Whether it is complex bends, branches, or different laying directions, they can be accurately presented in the three-dimensional model, providing a reliable structural foundation for subsequent analysis. By adding pipe fittings and ancillary facilities to the three-dimensional model, the three-dimensional model can include all key parts of the molten salt pipeline system to form a complete simulation object, thereby making the subsequent corrosion process simulation analysis closer to the actual working conditions and avoiding the result deviation caused by ignoring some facilities. By selecting appropriate pipeline materials from the material library of the three-dimensional modeling software according to the pipeline material of the actual molten salt pipeline and adding them to the three-dimensional model, and adding the density, elastic modulus, and Poisson's ratio of the pipeline material to the three-dimensional model, the three-dimensional model can accurately simulate the mechanical properties of the pipeline material of the actual molten salt pipeline under different working conditions, such as force deformation and stress distribution, providing a basis for evaluating the structural safety of the molten salt pipeline. By defining the density, viscosity, specific heat capacity, and electrical conductivity of the molten salt in the 3D model of the molten salt pipeline, 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.

[0088] For example, in step S4, the real-time corrosion rate and molten salt pipeline data are used to simulate the actual corrosion of the molten salt pipeline based on the corrosion kinetics model and thermodynamic model corresponding to the three-dimensional model to obtain simulation results, including:

[0089] Collect the pipe material, size and real-time corrosion rate of the actual molten salt pipeline, process and analyze it to establish a database, and explore the correlation between the pipe material, size and real-time corrosion rate of the actual molten salt pipeline;

[0090] Mesh 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 based on the database;

[0091] Based on the meshed three-dimensional model, and with the support of the corrosion kinetics model and thermodynamic model corresponding to the three-dimensional model, the finite element solution method combined with Python programming is used to simulate the actual corrosion process of the molten salt pipeline. The simulation calculation process is monitored and visual simulation results are obtained to analyze the corrosion indicators through the visual simulation results.

[0092] This implementation method systematically integrates information by collecting the pipe materials, dimensions, and real-time corrosion rates of actual molten salt pipelines and establishing a database. By exploring the correlation between the pipe materials, dimensions, and real-time corrosion rates of actual molten salt pipelines, the inherent connection between the pipe material characteristics, dimensions, and real-time corrosion rates of actual molten salt pipelines can be discovered. This allows the determination of the dimensions at which actual molten salt pipelines made of a specific material are most susceptible to corrosion, providing data support for pipeline selection, design, and maintenance, enabling relevant personnel 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 based on database data, the simulation environment of the corrosion process in the actual molten salt pipeline can be made highly close to the actual operating conditions. The three-dimensional model of the actual molten salt pipeline is more accurate, providing a reliable foundation for finite element simulation and more accurately predicting the corrosion behavior of molten salt pipelines under different operating conditions, such as corrosion evolution under extreme conditions of high temperature and high pressure. By using the finite element solution method combined with Python programming to simulate the corrosion process of actual molten salt pipelines, Python's rich library resources can be used to efficiently handle complex numerical calculations. By simulating the corrosion process of actual molten salt pipelines, supported by the corrosion kinetics and thermodynamic models corresponding to the three-dimensional model, we can deeply analyze the corrosion reaction rate and the microscopic process of electrode potential changes in actual molten salt pipelines. By monitoring the simulation calculation process, we can ensure the reliability of the results and promptly identify and resolve calculation anomalies. 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 these intuitive graphics, personnel can quickly locate areas of actual molten salt pipelines with high corrosion risk and analyze the impact trends of different factors on corrosion. This provides a clear basis for formulating targeted protective measures, improving work efficiency and scientific decision-making.

[0093] For example, based on the meshed 3D model, supported by the corresponding corrosion kinetics and thermodynamic models, the finite element method combined with Python programming is used to simulate the actual corrosion process of the molten salt pipeline. The simulation calculation process is monitored and visualized simulation results are obtained, including:

[0094] Based on the corrosion kinetics model, the rate and progression of corrosion reactions in actual molten salt pipelines are simulated. Based on the thermodynamic model, whether the corrosion reaction in actual molten salt pipelines can proceed spontaneously and the direction of the corrosion reaction are determined. Based on the three-dimensional model, the electrode potential is calculated based on the activity of the substances in the electrode reaction of the actual molten salt pipeline and the standard electrode potential. Different electrode potentials are compared to clarify the possibility of corrosion reactions.

[0095] During the iterative solution process 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 and the simulation result is obtained. 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 state of equilibrium in the entire system of the three-dimensional model.

[0096] Using drawing software, the simulation results are plotted into a potential distribution cloud map of the actual molten salt pipeline. The potential distribution cloud map can be used to display the potential distribution status in the actual molten salt pipeline and comprehensively evaluate the corrosion risks in different areas of the actual molten salt pipeline.

[0097] Specifically, in the activation polarization model of the corrosion kinetics model, the rate of the metal anode dissolution reaction is described by the Butler-Volmer equation, which is expressed as: the current density is equal to the exchange current density multiplied by the difference of two exponential terms. In the difference between the two exponential terms, the first exponential term is the product of the anode 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 product of the cathode 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 difference between the above two exponential terms.

[0098] In thermodynamic models, the Nernst equation is used to calculate electrode potential. According to the Nernst equation, the electrode potential is the sum of the standard electrode potential and the product of the gas constant and the absolute temperature, divided by the product of the number of electrons in the reaction and the Faraday constant, multiplied by the natural logarithm of the ratio of the activity of the oxidized species to the activity of the reduced species.

[0099] During the finite element discretization process, within each mesh element of the three-dimensional model, unknown variables such as potential and concentration are interpolated using shape functions. For example, the potential at a point within a mesh element is equal to the product of the shape functions of each node and the corresponding node potential. The same principle applies to concentration. A weighted integration of the governing equations over the mesh elements yields the element's stiffness matrix and load vector. The relevant matrices and load vectors for all elements are then assembled to form the overall system of linear equations.

[0100] When solving numerically, the unknown variable vector is obtained by inverting the global stiffness matrix and multiplying it by the global load vector.

[0101] During the monitoring simulation calculation process, for each iterative solution, the residual corresponding to the three-dimensional model is calculated. The residual is the product of the overall stiffness matrix and the unknown variable vector minus the norm of the overall load vector. When the calculated residual is less than the preset convergence threshold, the calculation is considered to have reached convergence, the iterative solution is stopped, and the corresponding simulation results are output.

[0102] In the corrosion rate calculation of the simulation results analysis, according to Faraday's law, the actual corrosion rate of the 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.

[0103] Exemplarily, in step S5, based on the simulation results and in combination with multiple molten salt pipeline corrosion factors, the risk level of the molten salt pipeline in each grid area is calculated separately, including:

[0104] For each grid area, the corrosion factors of each molten salt pipeline are quantified and weighted to obtain the corresponding risk level. Among them, the corrosion factors of molten salt pipelines include real-time corrosion rate, corrosion depth, environmental severity, and pipeline importance.

[0105] The corrosion depth was measured based on nondestructive testing methods;

[0106] The severity of the environment is obtained by scoring the severity of the actual environment in which the molten salt pipeline is located. The score range of the severity of the environment is 1-5, and the higher the score, the worse the environment.

[0107] The importance of pipelines is obtained by evaluating the role and impact range of actual molten salt pipelines in the pipeline transportation system. Pipelines that transport key media and connect important equipment are of high importance; auxiliary pipelines are of low importance. The score range of pipeline importance is 1-5, and the higher the score, the higher the pipeline importance.

[0108] For example, each molten salt pipeline corrosion factor is quantified and weighted to obtain a corresponding risk level, including:

[0109] Calculate the risk level according to the following formula: :

[0110]

[0111] in, is the real-time corrosion rate, and its value is mapped between 0 and 1; is the corrosion depth; is the score of the severity of the environment, ranging from 1 to 5; is the score of pipeline importance, ranging from 1 to 5;

[0112] 、 、 、 They are 、 、 、 The weight of , each weight can be determined based on historical data.

[0113] Exemplarily, in step S5, based on the risk level corresponding to each grid area, the risk level threshold ranges corresponding to different risk categories are determined, including:

[0114] Set the risk level threshold range corresponding to the risk category low risk to: ;

[0115] Set the risk level threshold range corresponding to the risks in the risk category to: ;

[0116] Set the risk level threshold range corresponding to the high risk risk category to: .

[0117] Different risk categories can be configured with different warning methods. For example, for actual molten salt pipelines in grid areas classified as low risk, regular reminders can be issued through the power plant's internal management system. For actual molten salt pipelines in grid areas classified as medium risk, in addition to reminders through the power plant's internal management system, early warning text messages can be sent to operations and maintenance personnel. For actual molten salt pipelines in grid areas classified as high risk, audible and visual alarms can be immediately triggered, and the information can be highlighted on the large screen in the monitoring center.

[0118] Different targeted maintenance measures can be implemented for molten salt pipelines belonging to different risk categories. For example, for low-risk pipelines, daily inspections can be strengthened. For medium-risk pipelines, inspection cycles can be shortened, and corroded areas can be repaired with anti-corrosion coatings. For high-risk pipelines, immediate downtime and maintenance can be arranged, with severely damaged pipeline components replaced to ensure the safe and stable operation of the molten salt pipeline system.

[0119] After obtaining the risk level corresponding to each grid area in step S5, the risk category corresponding to the risk level threshold range of the risk level corresponding to each grid area can be used as the risk category of each grid area. Based on the risk category of each grid area, an early warning is issued through the early warning method corresponding to the corresponding risk category, and targeted maintenance measures corresponding to the corresponding risk category are taken.

[0120] In order to enable those skilled in the art to better understand the above embodiment, a specific example is provided below for description.

[0121] In a large-scale solar thermal power station, molten salt pipelines serve as key heat transfer and storage media. Their safe and stable operation plays a decisive role in the station's efficient power generation. Molten salt is highly corrosive in high-temperature environments, posing a severe challenge to the pipeline's durability. To effectively monitor molten salt pipeline corrosion, the station implemented a real-time molten salt pipeline corrosion monitoring method. This method covers a series of steps, from grid division to risk response. These steps are described in detail below.

[0122] Grid division: First, obtain the design drawings of the molten salt pipeline containing detailed design information, use professional image processing software to analyze the design drawings, and use edge detection algorithms to accurately outline the edges of the molten salt pipeline area in the design drawings to obtain the pipeline contour information. Afterwards, use a fixed point at the starting end of the pipeline in the design drawing as the origin of the Cartesian coordinate system, stipulate that the x-axis to the right is the positive direction and the y-axis upward is the positive direction in the Cartesian coordinate system, and construct a spatial 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 to be 10cm×10cm based on the complexity and actual size of the molten salt pipeline. Subsequently, divide the entire bounding box into a number of initial grids, and determine 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, proceed The grid is subdivided into 5cm×5cm sub-grids in one step; the initial grid that does not intersect with the molten salt pipeline area remains unchanged, and the grids that still intersect with the molten salt pipeline area are continuously subdivided until the maximum number of subdivisions is 10 times and the minimum grid size after subdivision is less than the preset size threshold of 1cm×1cm. Finally, the grid division result is saved as a data file, and the coordinate information of each grid and the identification of whether it intersects with the molten salt pipeline area are recorded in the data file. The grid division effect is intuitively displayed through visualization software to lay a precise spatial positioning foundation for subsequent monitoring work.

[0123] Data Collection: Temperature sensors, flow rate sensors, and pressure sensors are installed at the actual molten salt pipeline locations corresponding to each defined grid area. The temperature sensors are high-temperature-resistant thermocouples that can accurately measure temperatures within the range of -200°C to 1300°C with an accuracy of ±0.5°C. The flow rate sensors are electromagnetic flowmeters that can accommodate flow velocities from 0.1 m / s to 10 m / s, with a measurement error of no more than ±1%. The pressure sensors are high-precision strain-gauge pressure gauges that can measure pressures from 0 MPa to 10 MPa with an accuracy of ±0.2%FS. These sensors collect real-time temperature, flow rate, and pressure data from the actual molten salt pipeline. This data is transmitted to a data processing unit via a wireless transmission module. The data processing unit preprocesses the collected data to remove outliers and noise, then integrates the processed data into a dataset that is updated every 10 minutes to ensure that the data in the dataset reflects the real-time status of the molten salt in the actual molten salt pipeline.

[0124] Real-time corrosion rate calculation: An electrochemical workstation is used to measure the electrochemical parameters of the pipeline material, such as open circuit potential and polarization resistance. Based on these electrochemical parameters, combined with real-time collected temperature and flow rate data, the corrosion current density is calculated according to the Stern-Gerri equation in electrochemical corrosion theory. In the molten salt system of this power station, the Stern-Gerri constant was determined through a large number of preliminary experiments. 25mV. Polarization resistance Obtained through electrochemical impedance spectroscopy measurement. At a certain moment, when the pipeline polarization resistance corresponding to a certain grid area is 500Ω·cm², the corrosion current density of the grid area is: The corrosion current density is obtained Then, using the formula Calculate real-time corrosion rates , the real-time corrosion rate of the actual molten salt pipeline corresponding to different grid areas can be accurately calculated.

[0125] 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 3D model defines the material properties of the pipeline in detail, including the density, elastic modulus, and Poisson's ratio of the pipeline material. The density, viscosity, specific heat capacity, and conductivity of the molten salt are also accurately set. The calculated real-time corrosion rate of the actual molten salt pipeline is used as the input condition. Based on the corrosion kinetics model and thermodynamic model corresponding to the 3D model, the corrosion situation of the actual molten salt pipeline is simulated in the 3D simulation software. During the simulation process, the effects of temperature, flow rate, and pressure on corrosion are fully considered. The finite element solution method is combined with Python programming. Through iterative calculations, the corrosion state of the actual molten salt pipeline at different time points is simulated, and the corresponding simulation results are obtained, such as the formation and expansion of corrosion pits and changes in pipeline wall thickness. After simulation analysis, the corrosion development trend of different areas of the pipeline is clearly presented, providing an intuitive and reliable basis for subsequent risk assessment.

[0126] Risk response: Based on the comprehensive simulation results and multiple corrosion factors of the actual molten salt pipeline, including pipeline material, real-time corrosion rate, environment, especially the severity of the environment, and pipeline importance, i.e. the importance of the actual molten salt pipeline in the power plant system, the risk level of the molten salt pipeline in each grid area is calculated. , risk level The calculation formula is ,in, is the normalized value of the real-time corrosion rate, is the normalized value of corrosion depth, is the score of the severity of the environment, is the score of pipeline importance, 、 、 、 They are 、 、 、 The weight of , , , , according to the calculation results of the risk level corresponding to each grid area, the risk categories and corresponding risk level threshold ranges are determined as follows: low risk , medium risk , high risk . When issuing warnings through the warning methods corresponding to the corresponding risk categories, regular reminders will be given for the actual molten salt pipelines in the grid areas with low risk categories through the internal management system of the power station. For the actual molten salt pipelines in the grid areas with medium risk categories, in addition to reminders through the internal management system of the power station, warning text messages will be sent to the operation and maintenance personnel. For the actual molten salt pipelines in the grid areas with high risk categories, an audible and visual alarm will be triggered immediately, and the alarm will be highlighted on the large screen of the monitoring center. When taking targeted maintenance measures corresponding to the corresponding risk categories, daily inspections will be strengthened for the actual molten salt pipelines with low risk. For the actual molten salt pipelines with medium risk, the inspection cycle will be shortened, and the corroded parts will be repaired with anti-corrosion coatings. For the actual molten salt pipelines with high risk, shutdown maintenance will be arranged immediately, and severely damaged pipeline components will be replaced to ensure the safe and stable operation of the molten salt pipeline system.

[0127] By implementing the above-mentioned real-time monitoring method for molten salt pipeline corrosion, the solar thermal power station has effectively improved its monitoring and prevention capabilities for molten salt pipeline corrosion, can promptly detect and address potential corrosion problems, reduce the number of shutdowns and maintenance costs caused by pipeline corrosion, and ensure the efficient and stable power generation of the power station.

[0128] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only illustrate the principles of the present invention. Various changes and improvements are possible without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the invention as 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 comprises: Step S1: obtaining a design drawing of a molten salt pipeline, and using a Cartesian coordinate system, adaptively dividing the molten salt pipeline area in the design drawing into a plurality of grid areas; Step S2: installing monitoring sensors in the actual molten salt pipelines corresponding to the grid areas, respectively, and using the monitoring sensors to collect molten salt pipeline data in real time, the molten salt pipeline data including temperature data, flow rate data, and pressure data in the actual molten salt pipelines; Step S3, calculating the real-time corrosion rate of the actual molten salt pipeline corresponding to each grid area using electrochemical corrosion theory based on the electrochemical parameters and the temperature data and the flow rate data; Step S4: constructing a three-dimensional model of the actual molten salt pipeline, and using the real-time corrosion rate and the molten salt pipeline data, simulating the corrosion of the actual molten salt pipeline based on a corrosion kinetics model and a thermodynamic model corresponding to the three-dimensional model to obtain a simulation result; Step S5: Based on the simulation results and in combination with multiple molten salt pipeline corrosion factors, respectively calculate the risk level of the molten salt pipeline in each of the grid areas; based on the risk level corresponding to each of the grid areas, determine the risk level threshold range corresponding to different risk categories; based on the risk level corresponding to each of the grid areas, respectively determine the risk category of each of the grid areas; for each of the grid areas with different risk categories, issue a warning using a different warning method, and take corresponding targeted maintenance measures; In step S4, the real-time corrosion rate and the molten salt pipeline data are used to simulate the corrosion of the actual molten salt pipeline based on the corrosion kinetics model and thermodynamic model corresponding to the three-dimensional model to obtain a simulation result, including: Collecting the pipe material, size and real-time corrosion rate of the actual molten salt pipe, processing and analyzing to establish a database, and mining the correlation between the pipe material, size and real-time corrosion rate of the actual molten salt pipe; Meshing the three-dimensional model, setting boundaries and initial conditions, and determining and adjusting parameters of the three-dimensional model based on the database; Based on the meshed three-dimensional model, supported by the corrosion kinetics model and the thermodynamics model corresponding to the three-dimensional model, the finite element method combined with Python programming is used to simulate the corrosion process of the actual molten salt pipeline, the simulation calculation process is monitored, and visual simulation results are obtained; Based on the meshed three-dimensional model, supported by the corrosion kinetics model and the thermodynamics model corresponding to the three-dimensional model, the finite element method combined with Python programming is used 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, simulating the corrosion reaction rate and corrosion process of the actual molten salt pipeline; Based on the thermodynamic model, determining whether the corrosion reaction of the actual molten salt pipeline can proceed spontaneously and the reaction direction of the corrosion reaction; Based on the three-dimensional model, the electrode potential is calculated according to the activity of the substances in the electrode reaction of the actual molten salt pipeline and the standard electrode potential, and different electrode potentials are compared to determine the possibility of the corrosion reaction; During the iterative solution process using the finite element solution method, a residual corresponding to the three-dimensional model is calculated for each iterative solution. When the residual is less than a preset convergence threshold, the iterative solution is stopped to obtain the simulation result. During the simulation process, the substances and charges generated by the corrosion reaction maintain a state of equilibrium in the entire system of the three-dimensional model. The simulation results are plotted into a potential distribution cloud diagram of the actual molten salt pipeline using drawing software.

2. The method for real-time monitoring of molten salt pipeline corrosion according to claim 1, characterized in that: The step S1 specifically includes: Obtaining the design drawing, and using an edge detection algorithm to determine the edge of the molten salt pipeline area in the design drawing to obtain pipeline contour information; Selecting a point on the design drawing as the origin of the Cartesian coordinate system, and specifying the positive direction of the x-axis and the positive direction of the y-axis in the Cartesian coordinate system; Based on the pipeline contour information, a minimum circumscribed rectangle of the molten salt pipeline area in the design drawing is calculated as a bounding box, and an initial grid size is determined based on the size and complexity of the molten salt pipeline; Dividing the bounding box into a plurality of initial grids based on the initial grid size and the Cartesian coordinate system; For each of the initial grids, determining whether it intersects with the molten salt pipeline area, and if so, further subdividing the corresponding initial grid; The subdivision operation is continued on the grids obtained after subdivision and still intersecting with the molten salt pipeline area until a maximum number of subdivisions is reached or the minimum grid size after subdivision is smaller than a 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, characterized in that: The step S3 specifically includes: The real-time corrosion rate is calculated according to the following formula: : in, is a constant, is the molar mass of the molten salt pipe metal, is the number of electron transfers when the metal in the molten salt pipe dissolves, is the density of the molten salt pipe metal, is the corrosion current density and , is the Stern-Geary constant, is the polarization resistance.

5. The method for real-time monitoring of molten salt pipeline corrosion according to claim 1, characterized in that: In step S4, constructing the three-dimensional model of the actual molten salt pipeline includes: Obtaining the design drawings, which include the direction, layout, and horizontal and vertical directions of the molten salt pipeline; Based on the design drawings, a basic model is constructed using 3D modeling software to draw the 3D model of the actual molten salt pipeline, and pipe fittings and ancillary facilities are added to the 3D model; Based on the pipe material of the actual molten salt pipe, selecting a suitable pipe material from the material library of the 3D modeling software and adding it to the 3D model, and adding the density, elastic modulus and Poisson's ratio of the pipe material to the 3D model; The density, viscosity, specific heat capacity and electrical conductivity of the molten salt are defined in the molten salt pipeline of the three-dimensional model, and the start time and corrosion rate distribution are added to the three-dimensional model.

6. The method for real-time monitoring of molten salt pipeline corrosion according to claim 1, characterized in that: In step S5, based on the simulation results and in combination with multiple molten salt pipeline corrosion factors, the risk level of the molten salt pipeline in each grid area is calculated respectively, including: For each grid area, each molten salt pipeline corrosion factor is quantified and weighted to obtain the corresponding risk level; wherein 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 environmental severity is obtained by scoring the environmental severity of the actual environment in which the actual molten salt pipeline is located; The pipeline importance is obtained by evaluating the role and impact range of the actual molten salt pipeline in the pipeline transportation system.

7. The method for real-time monitoring of molten salt pipeline corrosion according to claim 6, characterized in that: The quantification and weighting of each of the molten salt pipeline corrosion factors to obtain a risk level includes: Calculate the risk level according to the following formula: : in, is the real-time corrosion rate, whose value is mapped between 0 and 1; is the corrosion depth; is the score of the severity of the environment, ranging from 1 to 5; is the score of pipeline importance, ranging from 1 to 5; 、 、 、 They are 、 、 、 The weight of .

8. The method for real-time monitoring of molten salt pipeline corrosion according to claim 7, characterized in that: In step S5, determining the risk level threshold ranges corresponding to different risk categories based on the risk level corresponding to each grid area includes: The risk level threshold range corresponding to the risk category low risk is set to: ; The risk level threshold range corresponding to the risk in the risk category is set to: ; The risk level threshold range corresponding to the high risk risk category is set to: .

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