Boss head weld defect evaluation method, device, equipment and medium for nuclear power plant

Abstract

The present application relates to the field of nuclear power plant engineering manufacturing technology, and discloses a BOSS head weld defect evaluation method, device, equipment and medium for a nuclear power plant, which comprises the following steps: obtaining finite element modeling data, model constraint conditions and operation collection data of a BOSS head to be evaluated after welding in a nuclear power plant; determining the length of the BOSS head region model to be selected according to the length; obtaining stress results by performing temperature field analysis, thermal stress analysis and mechanical load analysis; performing fatigue crack propagation and stress corrosion crack propagation by using a stress intensity factor analysis method to evaluate crack evaluation results; and performing fracture analysis on the weld defect evaluation results of the BOSS head to be evaluated and displaying repair measures. The present application realizes automatic, rapid and objective fracture analysis according to the actual operation of the nuclear power plant by using finite element modeling data, and outputs the weld defect evaluation results and measures, thereby avoiding leakage loss and improving the economic benefits of the nuclear power plant.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of nuclear power plant engineering manufacturing, and in particular to a BOSS head weld defect evaluation method, device, equipment and medium for a nuclear power plant. BACKGROUND

[0002] Currently, a BOSS head weld structure (a parent pipe opening, a BOSS pipe directly welded at the opening) is widely used in a nuclear power plant pipe system, and the welding of the BOSS head weld structure is mainly implemented by using an argon-electric combined (manual argon arc welding for base welding, stick arc welding for filling and covering) welding process. For a welded BOSS head, liquid penetrant (PT) inspection needs to be performed on the to-be-welded surface, the root pass and the finished weld surface to inspect the welding quality. However, this inspection cannot detect the internal quality of the weld. However, pores, cracks and incomplete fusion defects in the weld can easily become failure sources in a high-temperature and high-pressure service environment of a primary loop, thereby causing problems such as stress corrosion cracking of the BOSS head weld. Therefore, there is a lack of structural integrity evaluation of the BOSS head weld defect, and the stability of the BOSS head weld in a refueling cycle or the entire service life cannot be determined. SUMMARY

[0003] The present application provides a BOSS head weld defect evaluation method, device, equipment and medium for a nuclear power plant. The present application automatically, quickly and objectively completes fracture analysis according to the actual operation of the nuclear power plant by using finite element modeling data, and outputs the weld defect evaluation result after the BOSS head weld, so that corresponding measures such as repair or replacement can be taken in time, better technical support and protection can be provided for the safe operation of the nuclear power plant, great losses caused by not taking measures in time can be reduced, and the operation economic benefits of the nuclear power plant are improved.

[0004] A BOSS head weld defect evaluation method for a nuclear power plant, comprising:

[0005] receiving an evaluation request of a to-be-evaluated BOSS head after a weld in a nuclear power plant, and obtaining finite element modeling data, model constraint conditions and operation collection data associated with the to-be-evaluated BOSS head in the evaluation request;

[0006] determining a length of cutting according to a main pipe parameter in the finite element modeling data, and selecting a BOSS head area model from the finite element modeling data according to the length of cutting;

[0007] performing temperature field analysis, thermal stress analysis and mechanical load analysis on the BOSS head area model according to material parameters in the finite element modeling data, the model constraint conditions and the operation collection data, and obtaining a stress result;

[0008] The stress intensity factor analysis method is used to perform fatigue crack propagation and stress corrosion crack propagation on the stress result, and a crack evaluation result is obtained.

[0009] Fracture analysis is performed on the crack evaluation result, a weld defect evaluation result corresponding to the BOSS head to be evaluated is output, and corresponding repair measures are displayed according to the weld defect evaluation result.

[0010] A BOSS head weld defect evaluation device for a nuclear power plant comprises:

[0011] A receiving module is configured to receive an evaluation request for a BOSS head to be evaluated after welding in a nuclear power plant, and obtain finite element modeling data, model constraint conditions and operation acquisition data associated with the BOSS head to be evaluated in the evaluation request.

[0012] A cutting module is configured to determine a cutting length according to a main pipeline parameter in the finite element modeling data, and select a BOSS head region model from the finite element modeling data according to the cutting length.

[0013] An analysis module is configured to perform temperature field analysis, thermal stress analysis and mechanical load analysis on the BOSS head region model according to material parameters in the finite element modeling data, the model constraint conditions and the operation acquisition data, and obtain a stress result.

[0014] An evaluation module is configured to use a stress intensity factor analysis method to perform fatigue crack propagation and stress corrosion crack propagation on the stress result, and obtain a crack evaluation result.

[0015] An output module is configured to perform fracture analysis on the crack evaluation result, output a weld defect evaluation result corresponding to the BOSS head to be evaluated, and display corresponding repair measures according to the weld defect evaluation result.

[0016] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the BOSS head weld defect evaluation method for a nuclear power plant when executing the computer program.

[0017] A computer readable storage medium stores a computer program, and the computer program implements the steps of the BOSS head weld defect evaluation method for a nuclear power plant when executed by a processor.

[0018] The application provides a BOSS head weld defect evaluation method, device, equipment and medium for a nuclear power plant, which receives an evaluation request of a BOSS head to be evaluated after welding in the nuclear power plant, acquires finite element modeling data, model constraint conditions and operation collection data associated with the BOSS head to be evaluated in the evaluation request, determines an intercept length according to a main pipeline parameter in the finite element modeling data, and selects a BOSS head area model from the finite element modeling data according to the intercept length, performs temperature field analysis, thermal stress analysis and mechanical load analysis on the BOSS head area model according to material parameters in the finite element modeling data, the model constraint conditions and the operation collection data, obtains stress results, performs fatigue crack propagation and stress corrosion crack propagation on the stress results by using a stress intensity factor analysis method, obtains crack evaluation results, performs fracture analysis on the crack evaluation results, outputs a weld defect evaluation result corresponding to the BOSS head to be evaluated, and displays corresponding repair measures according to the weld defect evaluation result.

[0019] The application realizes the following steps: acquiring finite element modeling data, model constraint conditions and operation collection data in an evaluation request of a BOSS head to be evaluated after welding in a nuclear power plant, determining an intercept length according to a main pipeline parameter in the finite element modeling data, and selecting a BOSS head area model according to the intercept length, performing temperature field analysis, thermal stress analysis and mechanical load analysis on the BOSS head area model to obtain stress results, performing fatigue crack propagation and stress corrosion crack propagation on the stress results by using a stress intensity factor analysis method to evaluate crack evaluation results, performing fracture analysis on the crack evaluation results to analyze a weld defect evaluation result of the BOSS head to be evaluated, and displaying corresponding repair measures, so that the intercept length is automatically identified from the finite element modeling data, the BOSS head area model is selected, the algorithm of temperature field analysis, thermal stress analysis and mechanical load analysis is used to automatically output stress results, the stress intensity factor analysis method is used to perform fatigue crack propagation and stress corrosion crack propagation, the crack evaluation results are automatically evaluated, the weld defect evaluation result of the BOSS head to be evaluated is output through fracture analysis, and corresponding repair measures are made in time, therefore, the steps of stress analysis, stress extraction, hypothetical crack, stress intensity factor output and crack mechanics analysis are automatically performed according to the actual operation of the nuclear power plant through the finite element modeling data, fracture analysis is quickly completed, the weld defect evaluation result of the BOSS head after welding is objectively output, the stability of the BOSS head in the refueling cycle of the nuclear power plant or the entire service life of the nuclear power plant is determined, corresponding repair or replacement measures can be taken in time, technical support and protection for the safe operation of the nuclear power plant can be better provided, great losses caused by not taking measures in time are reduced, and the operation economic benefits of the nuclear power plant are improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and all other drawings obtained by those skilled in the art without creative labor based on these drawings also belong to the protection scope of the present application.

[0021] Figure 1 is a schematic diagram of an application environment of the BOSS head weld defect evaluation method for nuclear power plants in an embodiment of the present application;

[0022] Figure 2 is a flowchart of the BOSS head weld defect evaluation method for nuclear power plants in an embodiment of the present application;

[0023] Figure 3 is a flowchart of step S20 of the BOSS head weld defect evaluation method for nuclear power plants in an embodiment of the present application;

[0024] Figure 4 is a flowchart of step S30 of the BOSS head weld defect evaluation method for nuclear power plants in an embodiment of the present application;

[0025] Figure 5 is a flowchart of step S302 of the BOSS head weld defect evaluation method for nuclear power plants in an embodiment of the present application;

[0026] Figure 6 is a flowchart of step S40 of the BOSS head weld defect evaluation method for nuclear power plants in an embodiment of the present application;

[0027] Figure 7 is a principle block diagram of the BOSS head weld defect evaluation device for nuclear power plants in an embodiment of the present application;

[0028] Figure 8 is a schematic diagram of a computer device in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, and not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor also belong to the protection scope of the present application.

[0030] The BOSS head weld defect evaluation method for nuclear power plants provided by the present application can be applied in, for example, Figure 1The application environment is a network environment in which a client (computer device) communicates with a server through a network. The client (computer device) includes, but is not limited to, various personal computers, notebook computers, smart phones, tablet computers, and portable wearable devices. The server can be implemented by an independent server or a server cluster composed of multiple servers. The execution client (computer device) communicates with the server through a network. The execution client (computer device) includes, but is not limited to, various personal computers, notebook computers, smart phones, tablet computers, and portable wearable devices.

[0031] In an embodiment, as shown in Figure 2 A BOSS head weld defect evaluation method for a nuclear power plant is provided, including the following steps S10-S50:

[0032] S10, receiving an evaluation request of a BOSS head after welding in a nuclear power plant, obtaining finite element modeling data, model constraint conditions and operation acquisition data associated with the BOSS head in the evaluation request.

[0033] Understandably, in the application of the pipeline in the operation of the base station of the nuclear power plant, such as the reactor pipeline, the safety valve control pipeline, the cooling water flow pipeline and the like, the BOSS head (nuclear power plant special joint seat) connection of the branch pipeline on the parent pipeline will appear, that is, the parent pipeline is opened, the BOSS pipeline (branch pipeline) is directly welded at the opening, the connection of the two pipelines is connected through the BOSS head, and the welding process of the BOSS head weld structure is carried out. For the completed BOSS head weld, a three-dimensional model of the finite element modeling of the BOSS head is simulated by using ANSYS simulation tool software. In the process of finite element modeling, the three-dimensional model can be established by scanning and collecting the appearance size of the BOSS head after welding. When the selected BOSS head needs to be evaluated, the evaluation request is triggered. The BOSS head to be evaluated is the BOSS head after welding which needs to be evaluated for integrity and stability. The evaluation request includes the finite element modeling data, the model constraint conditions and the operation acquisition data associated with the BOSS head to be evaluated. The finite element modeling data is the data input and output in the process of establishing a three-dimensional model. The finite element modeling data includes a three-dimensional model, a main pipeline parameter, a material parameter, a BOSS pipeline radius value and a BOSS pipeline wall thickness value. The three-dimensional model is a three-dimensional model of the main pipeline and the BOSS pipeline and the BOSS head weld. The main pipeline parameter is a parameter related to the main pipeline connected to the BOSS head to be evaluated. The material parameter is a material parameter related to the main pipeline and the BOSS pipeline. The BOSS pipeline radius value is the inner diameter of the BOSS pipeline. The BOSS pipeline wall thickness value is the wall thickness of the BOSS pipeline.

[0034] The model constraint condition is a constraint condition or rule set in advance according to a demand for constructing a thermal stress model or a constraint condition or rule set for constructing a mechanical load model. The model constraint condition includes a thermal stress model constraint condition and a mechanical load model constraint condition. The thermal stress model constraint condition is a constraint condition or rule set for constructing a thermal stress model. The mechanical load model constraint condition is a constraint condition or rule set for constructing a mechanical load model. The operation collection data are transient temperature data, thermal stress data and mechanical load stress data of each time point collected in a historical operation process of the main pipeline and the BOSS pipeline. The operation collection data include a temperature field cloud map, a thermal stress field cloud map and a mechanical load stress field cloud map.

[0035] S20, according to the main pipeline parameters in the finite element modeling data, determining the length of cutting, and selecting the BOSS head region model from the finite element modeling data according to the length of cutting.

[0036] Understandably, the main pipeline parameters include a main pipeline radius average value and a main pipeline wall thickness value. The main pipeline radius average value is an average radius value of the main pipeline connected with the BOSS head to be evaluated. The main pipeline wall thickness value is a wall thickness of the main pipeline connected with the BOSS head to be evaluated. The length of cutting is calculated by using a length of cutting function. The length of cutting is the length of the main pipeline in the three-dimensional model selected from the finite element modeling data. The main pipeline outside the length of cutting is basically not affected by the stress caused by the discontinuous effect after the BOSS head is connected. The BOSS head region model can be selected from the three-dimensional model by the length of cutting. The BOSS head region model is a three-dimensional region of a cube with the length of cutting as the edge length selected from the three-dimensional model.

[0037] In an embodiment, as shown in FIG. 2, the step S20, that is, the step of determining the length of cutting according to the main pipeline parameters in the finite element modeling data and selecting the BOSS head region model from the finite element modeling data according to the length of cutting, includes: Figure 3

[0038] S201, inputting the main pipeline radius average value and the main pipeline wall thickness value into a length of cutting function, and calculating the shortest length by using the length of cutting function. The main pipeline parameters include the main pipeline radius average value and the main pipeline wall thickness value.

[0039] Understandably, the shortest length function is a function of the minimum length range affected by the BOSS head connection according to the stress distribution summarized in the historical collection. The length of cutting function is:

[0040] ​

[0041] wherein,

[0042] L min is the shortest length;

[0043] R m is the mean value of the main pipe radius; the mean value of the main pipe radius is the average of the outer diameter of the main pipe and the inner diameter of the main pipe;

[0044] t is the wall thickness value of the main pipe.

[0045] S202, the shortest length is rounded up to obtain the intercept length.

[0046] Understandably, the shortest length usually has a decimal point, that is, a decimal value, and the shortest length needs to be rounded to facilitate the construction of the temperature field model, the thermal stress field model and the mechanical load stress model of the subsequent intercepted BOSS head region model, therefore, the shortest length is rounded up to obtain the intercept length.

[0047] S203, the BOSS head region model is selected from the finite element modeling data with the convergence center in the finite element modeling data as the center point and the intercept length as the edge length; the convergence center is the intersection point of the center axis of the main pipe and the center axis of the BOSS head to be evaluated in the same plane.

[0048] Understandably, the BOSS head region model is selected from the finite element modeling data with the convergence center in the finite element modeling data as the center of the cube and the intercept length as the edge length of the cube, and the three-dimensional cube is determined as the BOSS head region model, wherein the convergence center is the intersection point of the center axis of the main pipe and the center axis of the BOSS head to be evaluated in the same plane, that is, the intersection point of the center axes of the two cylinders.

[0049] The present application realizes that the mean value of the main pipe radius and the wall thickness value of the main pipe are input into the intercept length function, the shortest length is calculated through the intercept length function, the shortest length is rounded up to obtain the intercept length, and the BOSS head region model is selected from the finite element modeling data with the convergence center in the finite element modeling data as the center point and the intercept length as the edge length, so that the intercept length function is used to automatically obtain the intercept length, the BOSS head region model affected by the stress caused by the discontinuous effect after the BOSS head is connected is scientifically and objectively intercepted through the intercept length, the temperature field model, the thermal stress field model and the mechanical load stress model of the subsequent intercepted BOSS head region model are facilitated, and the basic data for subsequent weld defect evaluation is provided.

[0050] S30, performing temperature field analysis, thermal stress analysis and mechanical load analysis on the BOSS head region model according to the material parameters in the finite element modeling data, the model constraint conditions and the operation collection data, to obtain stress results.

[0051] Understandably, the material parameters are material-related parameters of the main pipeline and the BOSS pipeline, the material parameters include main pipeline material parameters and BOSS pipeline material parameters, the main pipeline material parameters are the material model of the main pipeline, for example: the main pipeline material parameters are X2 CrNi 19.10, X2 CrNi 19.10 is a type of stainless steel pipe, the BOSS pipeline material parameters are the material model of the BOSS pipeline, for example: the BOSS pipeline material parameters are Z2 CND 18-12NC, Z2 CND 18-12NC is a type of stainless steel pipe for reactor coolant system pipeline, the model constraint conditions are constraint conditions or rules for constructing the thermal stress model according to the demand or constraint conditions or rules for constructing the mechanical load model, the model constraint conditions include the thermal stress model constraint conditions and the mechanical load model constraint conditions, the thermal stress model constraint conditions are constraint conditions or rules for constructing the thermal stress model, the mechanical load model constraint conditions are constraint conditions or rules for constructing the mechanical load model, the operation collection data are transient temperature data, thermal stress data and mechanical load stress data of the main pipeline and the BOSS pipeline at each time point collected in the working operation process, the operation collection data include temperature field cloud picture, thermal stress field cloud picture and mechanical load stress field cloud picture, the temperature field cloud picture is a change distribution diagram of the temperature of each point in the BOSS head region model changing with time, that is, through the temperature field cloud picture, the temperature distribution and change of the BOSS head region model changing with time can be seen, the thermal stress field cloud picture is a change distribution diagram of the thermal stress of each point in the BOSS head region model changing with time, that is, through the thermal stress field cloud picture, the thermal stress distribution and change of the BOSS head region model changing with time can be seen, the mechanical load stress field cloud picture is a change distribution diagram of the mechanical load stress of each point in the inner wall of the BOSS head region model changing with time, that is, through the mechanical load stress field cloud picture, the change of the mechanical load stress of the inner wall of the BOSS head region model changing with time can be seen.

[0052] The temperature field analysis process is to obtain transient temperature field data of each evaluation path from the temperature field nephogram in the operation acquisition data, and to draw the transient temperature field curve corresponding to each evaluation path. The thermal stress analysis process is to obtain transient thermal stress field data of each evaluation path from the thermal stress field nephogram in the operation acquisition data, and to draw the transient thermal stress field curve corresponding to each evaluation path. The mechanical load analysis process is to obtain transient mechanical load stress field data of each evaluation path from the mechanical load stress field nephogram in the operation acquisition data, and to draw the transient mechanical load stress curve corresponding to each evaluation path. The evaluation path is a path output after evaluation path identification. The evaluation path identification process is to find a path node set that coincides and is in a weld adjacent area in the constructed temperature field model, thermal stress field model and mechanical load stress model. The weld adjacent area is a three-dimensional area surrounded by the BOSS head welding position and expanded by a preset distance. All transient temperature field curves, all transient thermal stress curves and all transient mechanical load stress curves are summarized to determine the stress result, which reflects the stress distribution of temperature field, thermal stress field and mechanical load stress field in each evaluation path.

[0053] In an embodiment, as shown in FIG. 3, the step S30, i.e., the temperature field analysis, thermal stress analysis and mechanical load analysis of the BOSS head area model according to the material parameters in the finite element modeling data, the model constraint conditions and the operation acquisition data, obtains the stress result, including: Figure 4

[0054] S301, according to the material parameters in the finite element modeling data and the model constraint conditions, multi-dimensional structure unit division is performed on the BOSS head area model to divide a temperature field model, a thermal stress field model and a mechanical load stress model.

[0055] ​Understandably, the multi-dimensional structure unit division is divided into different division ways of constructing three-dimensional solid structure, the multi-dimensional structure unit division includes SOLID45, SOLID70, SOLID185 and SOLID285 and other element divisions in ANSYS simulation tool software, through the multi-dimensional structure unit division, different dimensional three-dimensional models can be divided from the BOSS head area model, the element division method suitable for temperature field, thermal stress field and mechanical load stress field is selected from the multi-dimensional structure unit division, for example: SOLID70 element division is used to divide the BOSS head area model to obtain the temperature field model, SOLID185 element division is used to divide the BOSS head area model to obtain the thermal stress model, and SOLID185 element division is used to divide the BOSS head area model to obtain the mechanical load stress model.

[0056] In an embodiment, the step S301, that is, the multi-dimensional structure unit division of the BOSS head area model according to the material parameters in the finite element modeling data and the model constraint conditions, includes:

[0057] S3011, according to the material parameters and the thermal stress model constraint conditions, the first structure unit division and the second structure unit division are respectively performed on the BOSS head area model, and the temperature field model and the thermal stress field model corresponding to the BOSS head area model are respectively obtained; the model constraint conditions include the thermal stress model constraint condition and the mechanical load model constraint condition.

[0058] Understandably, the structure unit division method of the first structure unit division and the second structure unit division can be set according to requirements, for example, the first structure unit division is SOLID70 element division, the second structure unit division is SOLID185 element division, and the first structure unit division and the second structure unit division can be the same or different.

[0059] SOLID70 is a structure unit with heat conduction capacity, which has eight nodes, each node has only one temperature degree of freedom, and can be used for three-dimensional steady-state or transient thermal analysis problems. It can be understood that the BOSS head region model is divided into multiple SOLID70 structure units, and the main pipe material parameters and the BOSS pipe material parameters are used to divide the main pipe and the BOSS pipe in the BOSS head region model according to the thermal stress model constraint condition, so as to divide the multiple SOLID70 structure units, and then the multiple SOLID70 structure units are spliced to form a temperature field model. SOLID185 is a three-dimensional solid structure modeling unit, which has eight nodes with eight degrees of freedom, and has a mixed stress element of elastic deformation between material properties with orthogonal anisotropy. According to the main pipe material parameters and the BOSS pipe material parameters, and the thermal stress model constraint condition, the SOLID185 unit division method is used to divide the main pipe and the BOSS pipe in the BOSS head region model with different materials, so as to divide the multiple SOLID185 structure units, and then the multiple SOLID185 structure units are spliced to form a thermal stress field model.

[0060] S3012, according to the material parameters and the mechanical load model constraint condition, the third structure unit of the BOSS head region model is divided, and the mechanical load stress model corresponding to the BOSS head region model is obtained.

[0061] It can be understood that the third structure unit division can be set according to requirements, for example, the third structure unit division is SOLID185 unit division, the mechanical load model constraint condition is the constraint condition or rule for constructing the mechanical load model, according to the main pipe material parameters and the BOSS pipe material parameters, the SOLID185 unit division is performed on the inner wall of the main pipe and the inner wall of the BOSS pipe (including the inner wall of the BOSS head) according to the mechanical load model constraint condition, and the mechanical load stress elements of the inner wall of the main pipe and the inner wall of the BOSS pipe under different materials are divided, so that the mechanical load stress model can be spliced.

[0062] The application realizes first structure unit division and second structure unit division of the BOSS head region model by constraints of the material parameters and the thermal stress model, respectively, to obtain a temperature field model and a thermal stress field model corresponding to the BOSS head region model; third structure unit division of the BOSS head region model is performed according to the material parameters and the mechanical load model constraints to obtain a mechanical load stress model corresponding to the BOSS head region model, so that the thermal stress model constraints and the mechanical load model constraints are used to automatically adopt structure unit division methods suitable for different dimensions to establish temperature field, thermal stress field and mechanical load stress field models of the main pipeline and the BOSS pipeline of different materials, thereby providing a multi-dimensional data basis for subsequent BOSS head weld defect evaluation of the nuclear power plant and improving the accuracy and reliability of the evaluation.

[0063] S302, the temperature field model, the thermal stress field model and the mechanical load stress model are evaluated and identified, and a plurality of evaluation paths are identified.

[0064] Understandably, the evaluation path identification process is to find a set of path nodes that coincide and are in the weld adjacent region in the constructed temperature field model, thermal stress field model and mechanical load stress model, so that a plurality of evaluation paths can be drawn, and the stress intensity factor can be extracted through the evaluation paths.

[0065] In an embodiment, as shown in Figure 5 In the step S302, that is, the temperature field model, the thermal stress field model and the mechanical load stress model are evaluated and identified, and a plurality of evaluation paths are identified, which includes:

[0066] S3021, find path nodes that coincide and are in the weld adjacent region in the BOSS head region model in the temperature field model, the thermal stress field model and the mechanical load stress model.

[0067] Understandably, the coinciding path nodes in the temperature field model and the thermal stress field model are mainly sought, because the mechanical load stress model only establishes a model in the region of the inner wall, so the intersection with the temperature field model and the thermal stress field model is less, that is, the nodes that coincide between the two models are first sought through the temperature field model and the thermal stress field model, then the intersection of the coinciding nodes and the nodes in the mechanical load stress model is sought, finally the set of nodes of the nearly straight path is explored through path exploration, and the two ends of the extended nearly straight path are extended to the inner wall and the outer wall of the BOSS pipeline, so that the nodes of the extended nearly straight path are determined as the path nodes.

[0068] S3022, performing an evaluation path rule detection on all the path nodes to obtain a detection result.

[0069] It can be understood that the evaluation path rule detection is a preset rule set for the evaluation path, for example, whether the evaluation path formed by the path nodes meets the weld area of the BOSS head to be evaluated, whether the total number of the paths formed by the path nodes exceeds the preset number, and whether there are other path nodes within the preset adjacent distance range, etc. The detection result can be output through the evaluation path rule detection. The detection result reflects whether there are path nodes meeting the evaluation path rule. The detection result includes the rule meeting and the rule not meeting.

[0070] S3023, if the detection result is the rule meeting, the path nodes meeting the rule and being adjacent are marked and distinguished, and the path nodes with the same mark are connected to obtain the evaluation path.

[0071] S3024, if the detection result is the rule not meeting, the evaluation path is selected in the weld adjacent area according to the preset direction and the cross section.

[0072] It can be understood that if the detection result is the rule not meeting, it means that no path node meeting the evaluation path rule is found, and the path needs to be selected in the weld adjacent area according to the preset direction and the cross section. The preset direction can be set according to the demand, such as 0°, 45°, 90° and 180° in the radial plane of the BOSS pipe. The cross section is obtained according to the axial direction of the preset direction. The weld area of the BOSS head to be evaluated in the cross section is selected by 4 path directions, and 4 evaluation paths are selected, that is, 16 evaluation paths.

[0073] The application realizes the following: finding the path nodes that coincide in the temperature field model, the thermal stress field model and the mechanical load stress model and are in the weld adjacent area of the BOSS head area model; performing an evaluation path rule detection on all the path nodes to obtain a detection result; if the detection result is the rule meeting, the path nodes meeting the rule and being adjacent are marked and distinguished, and the path nodes with the same mark are connected to obtain the evaluation path; if the detection result is the rule not meeting, the evaluation path is selected in the weld adjacent area according to the preset direction and the cross section, so that the evaluation path meeting the evaluation path rule is automatically selected, which provides a basis for the subsequent extraction and analysis of the stress result.

[0074] S303, performing temperature field analysis, thermal stress analysis and mechanical load analysis on each of the evaluation paths according to the operation collected data, to obtain transient temperature field curves, transient thermal stress curves and transient mechanical load stress curves corresponding to each of the evaluation paths.

[0075] Understandably, the process of temperature field analysis is to screen out transient temperature field data of each node in each of the evaluation paths from the temperature field cloud diagram in the operation collected data, to obtain transient temperature field data of each of the evaluation paths, and to analyze the transient temperature field data of each of the evaluation paths, analyze the temperature distribution when the transient temperature changes sharply, and depict the transient temperature field curve corresponding to each of the evaluation paths, which reflects the temperature change curve of each node over time; the process of thermal stress analysis is to screen out transient thermal stress field data of each node in each of the evaluation paths from the thermal stress field cloud diagram in the operation collected data, to obtain transient thermal stress field data of each of the evaluation paths, and to analyze the transient thermal stress field data of each of the evaluation paths, analyze the thermal stress distribution when the transient temperature changes sharply, and depict the transient thermal stress field curve corresponding to each of the evaluation paths, which reflects the thermal stress change curve of each node over time; the process of mechanical load analysis is to screen out transient mechanical load stress field data of each node in each of the evaluation paths from the mechanical load stress field cloud diagram in the operation collected data, to obtain transient mechanical load stress field data of each of the evaluation paths, and to analyze the transient mechanical load stress field data of each of the evaluation paths, analyze the mechanical load stress distribution when the transient temperature changes sharply, and depict the transient mechanical load stress field curve corresponding to each of the evaluation paths, which reflects the mechanical load stress change curve of each node over time.

[0076] In an embodiment, the step S303, i.e., the temperature field analysis, thermal stress analysis and mechanical load analysis on each of the evaluation paths according to the operation collected data to obtain transient temperature field curves, transient thermal stress curves and transient mechanical load stress curves corresponding to each of the evaluation paths, includes:

[0077] S3031, obtaining transient temperature field data of each of the evaluation paths from the temperature field cloud diagram in the operation collected data, and performing temperature field analysis on the transient temperature field data of each of the evaluation paths to depict the transient temperature field curve corresponding to each of the evaluation paths.

[0078] Understandably, the transient temperature field data of each node in each of the evaluation paths is screened from the temperature field nephogram in the operation collected data, so as to obtain the transient temperature field data of each of the evaluation paths, and the transient temperature field data of each of the evaluation paths is analyzed, the temperature distribution when the transient temperature changes sharply is analyzed, for example, the temperature distribution of the temperature from 345 degrees to 10 degrees at the 100th second, the temperature distribution of the temperature from 10 degrees to 345 degrees at the 3700th second, the process of drawing the transient temperature field curve corresponding to each of the evaluation paths is described, the transient temperature field curve reflects the temperature change curve of each node with time, the transient temperature field data refers to the data set of the transient temperature at each node of the evaluation path, the transient temperature field data is a function of time and temperature coordinates, and reflects the temperature distribution over time.

[0079] S3032, the transient thermal stress field data of each of the evaluation paths is obtained from the thermal stress field nephogram in the operation collected data, and the transient thermal stress field data of each of the evaluation paths is analyzed, and the transient thermal stress field curve corresponding to each of the evaluation paths is described.

[0080] Understandably, the transient thermal stress field data of each node in each of the evaluation paths is screened from the thermal stress field nephogram in the operation collected data, so as to obtain the transient thermal stress field data of each of the evaluation paths, and the transient thermal stress field data of each of the evaluation paths is analyzed, the thermal stress distribution when the transient temperature changes sharply is analyzed, for example, the thermal stress distribution of the temperature from 345 degrees to 10 degrees at the 100th second, the thermal stress distribution of the temperature from 10 degrees to 345 degrees at the 3700th second, the process of drawing the transient thermal stress field curve corresponding to each of the evaluation paths is described, the transient thermal stress field curve reflects the thermal stress change curve of each node with time, the transient thermal stress field data refers to the data set of the transient thermal stress at each node of the evaluation path, the transient thermal stress field data is a function of time and thermal stress coordinates, and reflects the thermal stress distribution over time.

[0081] S3033, the transient mechanical load stress field data of each of the evaluation paths is obtained from the mechanical load stress field nephogram in the operation collected data, and the transient mechanical load stress field data of each of the evaluation paths is analyzed, and the transient mechanical load stress curve corresponding to each of the evaluation paths is described.

[0082] Understandably, the transient mechanical load stress field data of each node in each of the evaluation paths is screened from the mechanical load stress field cloud diagram in the operation collected data, so as to obtain the transient mechanical load stress field data of each of the evaluation paths, and the transient mechanical load stress field data of each of the evaluation paths is analyzed, the mechanical load stress distribution under the condition of the transient temperature drastic change is analyzed, for example, the mechanical load stress distribution under the condition that the temperature is suddenly reduced from 345 degrees to 10 degrees at the 100th second, the mechanical load stress distribution under the condition that the temperature is rapidly increased from 10 degrees to 345 degrees at the 3700th second, the process of drawing the transient mechanical load stress field curve corresponding to each of the evaluation paths is described, the transient mechanical load stress field curve reflects the mechanical load stress change curve of each node with time, the transient mechanical load stress field data refers to the data set of the transient mechanical load stress on each node of the evaluation path, the transient mechanical load stress field data is a function of time and mechanical load stress coordinates, and reflects the distribution of the mechanical load stress over time.

[0083] The step S3031, the step S3032 and the step S3033 can be executed in parallel or in series, and the order is not limited.

[0084] The present application realizes that the transient temperature field data of each of the evaluation paths is obtained from the temperature field cloud diagram in the operation collected data, the temperature field analysis is performed on the transient temperature field data of each of the evaluation paths, and the transient temperature field curve corresponding to each of the evaluation paths is described; the transient thermal stress field data of each of the evaluation paths is obtained from the thermal stress field cloud diagram in the operation collected data, the thermal stress analysis is performed on the transient thermal stress field data of each of the evaluation paths, and the transient thermal stress field curve corresponding to each of the evaluation paths is described; the transient mechanical load stress field data of each of the evaluation paths is obtained from the mechanical load stress field cloud diagram in the operation collected data, the mechanical load analysis is performed on the transient mechanical load stress field data of each of the evaluation paths, and the transient mechanical load stress curve corresponding to each of the evaluation paths is described, so that the temperature field analysis method, the thermal stress field analysis method and the mechanical load stress field analysis method are used to analyze the operation collected data, the transient temperature field curve, the transient thermal stress field curve and the transient mechanical load stress curve of each of the evaluation paths are described, and the useful and effective data for the subsequent stress intensity factor can be objectively and intuitively obtained.

[0085] S304, all the transient temperature field curves are summarized to obtain the transient temperature field distribution, all the transient thermal stress curves are summarized to obtain the transient thermal stress distribution, and all the transient mechanical load stress curves are summarized to obtain the transient mechanical load stress distribution.

[0086] Understandably, all the transient temperature field curves are summarized in a three-dimensional coordinate of space, time and temperature to obtain the transient thermal stress distribution; all the transient thermal stress curves are summarized in a three-dimensional coordinate of space, time and thermal stress to obtain the transient thermal stress distribution; and all the transient mechanical load stress curves are summarized in a three-dimensional coordinate of space, time and mechanical load stress to obtain the transient mechanical load stress distribution.

[0087] S305, the transient temperature field distribution, the transient thermal stress distribution and the transient mechanical load stress distribution are determined as the stress result.

[0088] The application realizes multi-dimensional structure unit division of the BOSS head region model according to the material parameters in the finite element modeling data and the model constraint conditions, divides temperature field models, thermal stress field models and mechanical load stress models, performs evaluation path identification on the temperature field models, the thermal stress field models and the mechanical load stress models, identifies multiple evaluation paths, performs temperature field analysis, thermal stress analysis and mechanical load analysis on each evaluation path according to the operation collection data, obtains transient temperature field curves, transient thermal stress curves and transient mechanical load stress curves corresponding to each evaluation path, summarizes all the transient temperature field curves to obtain the transient temperature field distribution, simultaneously summarizes all the transient thermal stress curves to obtain the transient thermal stress distribution, and summarizes all the transient mechanical load stress curves to obtain the transient mechanical load stress distribution, determines the transient temperature field distribution, the transient thermal stress distribution and the transient mechanical load stress distribution as the stress result, thereby realizing automatic division of the temperature field models, the thermal stress field models and the mechanical load stress models through multi-dimensional structure unit division, automatic and scientific identification of the evaluation paths, and acquisition of stress results in the temperature dimension, the thermal stress dimension and the mechanical load stress dimension by using the temperature field analysis, the thermal stress analysis and the mechanical load analysis, reducing the cost of manual searching of the evaluation paths and analysis of the output stress results, improving the efficiency, and improving the accuracy and quality of the stress result output.

[0089] S40, a stress intensity factor analysis method is used to perform fatigue crack propagation and stress corrosion crack propagation on the stress result to obtain a crack evaluation result.

[0090] Understandably, the stress intensity factor analysis method is a method of performing polynomial fitting on the stress perpendicular to the crack surface on the position where the crack is located on the BOSS pipe wall thickness, and then calculating the stress intensity factor of the crack by using the stress intensity factor function, the fatigue crack propagation is an expansion method of estimating the fatigue life of the crack according to the fatigue crack propagation rate, the fatigue propagation rate is related to the BOSS pipe material parameters and the stress intensity factor, the stress corrosion crack propagation is an expansion method of estimating the corrosion life of the crack according to the stress corrosion crack propagation rate, the stress corrosion crack propagation rate is related to the BOSS pipe material parameters and the stress intensity factor, the fatigue crack propagation and the stress corrosion crack propagation are performed on the hoop crack area to obtain the hoop crack evaluation result, the fatigue crack propagation and the stress corrosion crack propagation are performed on the axial crack area to obtain the axial crack evaluation result, the crack evaluation result includes the hoop crack evaluation result and the axial crack evaluation result, and the crack evaluation result integrates the evaluation results of the hoop crack evaluation result and the axial crack evaluation result.

[0091] In an example, as shown in Figure 6 the step S40, that is, the stress intensity factor analysis method is used to perform fatigue crack propagation and stress corrosion crack propagation on the stress results to obtain a crack evaluation result, including:

[0092] S401, obtaining the BOSS pipe radius value and the BOSS pipe wall thickness value in the finite element modeling data.

[0093] S402, identifying a hoop crack area and an axial crack area according to the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameters in the material parameters.

[0094] Understandably, the process of identifying the hoop crack area is a process of detecting the distance between each node on the outer surface of the hoop crack area in the BOSS head area model and each all evaluation path according to the hoop crack parameters; the process of identifying the axial crack area is a process of detecting the maximum intersection between the axial crack area and all the evaluation paths in the BOSS head area model according to the semi-elliptical crack parameters.

[0095] In an embodiment, the step S402, that is, the hoop crack area and the axial crack area are identified according to the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameters in the material parameters, including:

[0096] S4021, obtaining, from a historical crack library, a circumferential crack parameter and a semi-elliptical crack parameter that match the BOSS pipe radius value, the BOSS pipe wall thickness value and the material parameter.

[0097] Understandably, the identification process is to obtain, from a historical crack library, a circumferential crack parameter and a semi-elliptical crack parameter that match the BOSS pipe wall thickness value and the BOSS pipe material parameter, the historical crack library stores circumferential crack parameters and semi-elliptical crack parameters generated by different pipe wall thicknesses of different materials collected historically, and learns the correlation between circumferential crack parameters and BOSS pipe inner diameter, material and pipe wall thickness, and the correlation between semi-elliptical crack parameters and BOSS pipe inner diameter, material and pipe wall thickness, so that the circumferential crack parameter and the semi-elliptical crack parameter that match the BOSS pipe radius value, the BOSS pipe wall thickness value and the material parameter can be obtained from the historical crack library. By assuming the crack condition of the BOSS head to be evaluated based on the historical data collected in the historical crack library, simulating the circumferential crack and semi-elliptical crack of the BOSS head to be evaluated, and evaluating the defect based on the simulated circumferential crack and semi-elliptical crack, the accuracy and reliability of the evaluation can be improved.

[0098] Wherein, the circumferential crack parameter is a related parameter of the circumferential crack, the circumferential crack parameter includes the depth of the circumferential crack and the width of the circumferential crack, the depth of the circumferential crack is three times the width of the circumferential crack, the semi-elliptical crack parameter is a related parameter of the semi-elliptical crack, the semi-elliptical crack parameter includes the depth of the semi-elliptical crack and the width of the semi-elliptical crack, the depth of the semi-elliptical crack is three times the width of the semi-elliptical crack.

[0099] S4022, identifying, in the BOSS head area model, a circumferential crack area with the smallest distance to all the evaluation paths according to the circumferential crack parameter.

[0100] Understandably, the process of identifying the circumferential crack area with the smallest distance to all the evaluation paths is to calculate the area of the outer surface of the circumferential crack according to the depth and width of the circumferential crack and the BOSS pipe radius value, move the center of the circumferential crack away from the main pipe along the central axis of the BOSS head to be evaluated, identify the position where the sum of the Euclidean distances of each node of the outer surface of the circumferential crack to all the evaluation paths reaches the minimum during the movement, and move to the minimum position, and determine the circumferential crack at this position as the circumferential crack area.

[0101] S4023, according to the semi-elliptical crack parameter, identifying an axial crack region with the largest intersection with all the evaluation paths in the BOSS head region model.

[0102] Understandably, the process of identifying the largest intersection with all the evaluation paths is to calculate the volume model of the semi-elliptical crack according to the depth and width of the semi-elliptical crack and the BOSS pipe radius value, move the center of the volume model along the central axis of the BOSS head to be evaluated away from the main pipe direction, and rotate in the radial direction of the BOSS head to be evaluated, find the position with the largest intersection volume with all the evaluation paths, and move to the position with the largest intersection volume. The semi-elliptical crack at this position is determined as the axial crack region.

[0103] Wherein, the step S4022 and the step S4023 can be executed in parallel, or in series, and the order is not limited.

[0104] The present application realizes that the circumferential crack parameters and the semi-elliptical crack parameters matched with them are obtained from the historical crack library according to the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameter in the material parameters; according to the circumferential crack parameters, identifying a circumferential crack region with the smallest distance from all the evaluation paths in the BOSS head region model; according to the semi-elliptical crack parameters, identifying an axial crack region with the largest intersection with all the evaluation paths in the BOSS head region model, so that the circumferential crack parameters and the semi-elliptical crack parameters are automatically obtained from the historical crack library, the weld defects of the BOSS head to be evaluated are simulated according to the circumferential crack parameters and the semi-elliptical crack parameters, and the circumferential crack region and the axial crack region are automatically identified, thereby improving the accuracy and reliability of subsequent defect evaluation.

[0105] S403, using stress intensity factor analysis method, polynomial fitting is performed on the transient temperature field distribution, the transient thermal stress distribution and the transient mechanical load stress distribution, and the circumferential crack stress intensity factor and the axial crack stress intensity factor are calculated through the stress intensity factor function.

[0106] Understandably, the stress intensity factor analysis method is a method of performing polynomial fitting on the stress perpendicular to the crack surface on the BOSS pipe wall thickness where the crack is located, and then calculating the stress intensity factor of the crack by using the stress intensity factor function. The process of polynomial fitting on the transient temperature field distribution, the transient thermal stress distribution and the transient mechanical load stress distribution is that according to the transient temperature field distribution combined with the hoop crack area and the axial crack area, the temperature stress results of the hoop crack area and the axial crack area can be respectively output by the ANSYS simulation tool software, according to the transient thermal stress field distribution combined with the hoop crack area and the axial crack area, the thermal stress results of the hoop crack area and the axial crack area can be respectively output by the ANSYS simulation tool software, according to the transient mechanical load stress distribution combined with the hoop crack area and the axial crack area, the mechanical load stress results of the hoop crack area and the axial crack area can be respectively output by the ANSYS simulation tool software, the hoop crack stress intensity factor is obtained by using the stress intensity factor function, multiplying and summing the temperature stress results, the thermal stress results and the mechanical load stress results of the hoop crack area by their respective weighting factors, taking the sum after summing and multiplying by obtained, wherein a1 is the crack depth of the hoop crack, the axial crack stress intensity factor is obtained by using the stress intensity factor function, multiplying and summing the temperature stress results, the thermal stress results and the mechanical load stress results of the axial crack area by their respective weighting factors, taking the sum after summing and multiplying by obtained, wherein a2 is the crack depth of the axial crack.

[0107] S404, according to the BOSS pipe material parameters, the hoop crack stress intensity factor and the axial crack stress intensity factor, respectively, the hoop crack area and the axial crack area are subjected to fatigue crack propagation and stress corrosion crack propagation, and crack evaluation results are obtained.

[0108] Understandably, the fatigue crack propagation is an extension method for estimating crack fatigue life according to a fatigue crack propagation rate, the fatigue propagation rate refers to the increase of crack length per cycle of alternating stress, the fatigue propagation rate is related to the BOSS pipe material parameters and stress intensity factor, the stress corrosion crack propagation is an extension method for estimating crack corrosion life according to a stress corrosion propagation rate, the stress corrosion propagation rate refers to the increase of crack propagation per cycle under the stress corrosion caused by stress, environment and material, the stress corrosion crack propagation rate is related to the BOSS pipe material parameters and stress intensity factor, the circumferential crack area is subjected to fatigue crack propagation and stress corrosion crack propagation to obtain a circumferential crack evaluation result, the axial crack area is subjected to fatigue crack propagation and stress corrosion crack propagation to obtain an axial crack evaluation result, and the circumferential crack evaluation result and the axial crack evaluation result are determined as the crack evaluation result.

[0109] The circumferential crack evaluation result indicates the crack propagation result at the end of each year in the life cycle of the nuclear power station base station where the BOSS head to be evaluated exists circumferential crack, and the axial crack evaluation result indicates the crack propagation result at the end of each year in the life cycle of the nuclear power station base station where the BOSS head to be evaluated exists semi-elliptical crack.

[0110] The application realizes that the BOSS pipe radius value and the BOSS pipe wall thickness value in the finite element modeling data are obtained, the circumferential crack area and the axial crack area are identified according to the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameter in the material parameters, the stress intensity factor analysis method is used to perform polynomial fitting on the transient temperature field distribution, the transient thermal stress distribution and the transient mechanical load stress distribution, and the circumferential crack stress intensity factor and the axial crack stress intensity factor are calculated through a stress intensity factor function, the circumferential crack area and the axial crack area are subjected to fatigue crack propagation and stress corrosion crack propagation according to the BOSS pipe material parameters, the circumferential crack stress intensity factor and the axial crack stress intensity factor, and a crack evaluation result is obtained, thus, the circumferential crack area and the axial crack area are automatically identified, the circumferential crack stress intensity factor and the axial crack stress intensity factor are calculated through the stress intensity factor function by using the stress intensity factor analysis method, and the crack evaluation result is output, the crack evaluation result of the circumferential crack and the semi-elliptical crack crack propagation per year can be scientifically, objectively and quickly output, a method for evaluating the crack propagation result from the circumferential and axial dimensions of the BOSS head weld defect structure is provided, technical support and guarantee for safe operation of the nuclear power station can be better provided, great loss caused by not taking timely measures is reduced, and the operation economic benefit of the nuclear power station is improved.

[0111] In an embodiment, the step S404, i.e., the fatigue crack propagation and stress corrosion crack propagation of the hoop crack region and the axial crack region according to the hoop crack stress intensity factor and the axial crack stress intensity factor, respectively, to obtain the crack evaluation result, comprises:

[0112] S4041, hoop fatigue crack propagation and hoop stress corrosion crack propagation of the hoop crack region according to the BOSS pipe material parameters and the hoop crack stress intensity factor to obtain the hoop crack evaluation result.

[0113] Understandably, the hoop fatigue crack propagation is an estimation of the fatigue crack propagation of the hoop crack region, and the hoop stress corrosion crack propagation is an estimation of the stress corrosion crack propagation of the axial crack region.

[0114] S4042, axial fatigue crack propagation and axial stress corrosion crack propagation of the axial crack region according to the BOSS pipe material parameters and the axial crack stress intensity factor to obtain the axial crack evaluation result.

[0115] Understandably, the axial fatigue crack propagation is an estimation of the fatigue crack propagation of the axial crack region, and the axial stress corrosion crack propagation is an estimation of the stress corrosion crack propagation of the axial crack region.

[0116] S4043, determining the hoop crack evaluation result and the axial crack evaluation result as the crack evaluation result.

[0117] The present application realizes the hoop fatigue crack propagation and hoop stress corrosion crack propagation of the hoop crack region according to the BOSS pipe material parameters and the hoop crack stress intensity factor to obtain the hoop crack evaluation result, the axial fatigue crack propagation and axial stress corrosion crack propagation of the axial crack region according to the BOSS pipe material parameters and the axial crack stress intensity factor to obtain the axial crack evaluation result, and determining the hoop crack evaluation result and the axial crack evaluation result as the crack evaluation result, so that the crack evaluation result is automatically evaluated from the crack defect situation in the hoop and axial dimensions.

[0118] S50, performing fracture analysis on the crack evaluation result, outputting the weld defect evaluation result corresponding to the BOSS head to be evaluated, and displaying the corresponding repair measures according to the weld defect evaluation result.

[0119] Understandably, the fracture analysis is an analysis process of the hoop crack evaluation result and the axial crack evaluation result, that is, on the one hand, the analysis of the hoop crack evaluation result is to analyze the hoop crack region of the BOSS head to be evaluated to evaluate the crack propagation amount on the 90° cross section, if the length of the initial hoop crack is 5 mm, the crack propagation amount at the end of the 40-year service life is 3.0984 mm, the length of the final crack at the end of the service life is 8.0984 mm, the service life pa=8.0984 mm, and the stress intensity factor is much smaller than the material toughness of the BOSS pipeline, so for this hoop crack, the structure will not rapidly fracture; on the other hand, the analysis of the axial crack evaluation result is to analyze the axial crack region of the BOSS head to be evaluated to evaluate the crack propagation amount on the 90° cross section, if the length of the initial hoop crack is 5 mm, the crack depth at the end of the 9th year is 14.4962 mm, the stress intensity factor is less than the material toughness, and 14.4962 mm has already exceeded 0.75 times (17.8*0.75=13.35 mm) of the wall thickness (17.8 mm) of the BOSS pipeline, the structure will exist the failure of plastic collapse, and the risk of coolant leakage will occur.

[0120] Among them, the hoop crack evaluation result and the axial crack evaluation result in the crack evaluation result are comprehensively analyzed, the ratio of the length and the depth of the crack propagation at the same time point is compared, and the year of the risk of fracture is compared, the weld defect evaluation result of the BOSS head to be evaluated is output, and the measures of digging and repairing or replacing the BOSS head to be evaluated in the xth year are displayed according to the weld defect evaluation result.

[0121] The application realizes the following through receiving an evaluation request of a BOSS head to be evaluated after a weld seam in a nuclear power plant, obtaining finite element modeling data, model constraint conditions and operation collection data associated with the BOSS head to be evaluated in the evaluation request; determining the intercept length according to the main pipeline parameters in the finite element modeling data, and selecting a BOSS head area model from the finite element modeling data according to the intercept length; performing temperature field analysis, thermal stress analysis and mechanical load analysis on the BOSS head area model according to the material parameters in the finite element modeling data, the model constraint conditions and the operation collection data, to obtain stress results; performing fatigue crack propagation and stress corrosion crack propagation on the stress results by using a stress intensity factor analysis method, to obtain crack evaluation results; performing fracture analysis on the crack evaluation results, outputting a weld defect evaluation result corresponding to the BOSS head to be evaluated, and displaying corresponding repair measures according to the weld defect evaluation result. In this way, the intercept length is automatically identified from the finite element modeling data, and the BOSS head area model is selected, the algorithm of temperature field analysis, thermal stress analysis and mechanical load analysis is used to automatically output the stress results, the stress intensity factor analysis method is used to perform fatigue crack propagation and stress corrosion crack propagation, and the crack evaluation results are automatically evaluated, so that the weld defect evaluation result of the BOSS head to be evaluated is output through fracture analysis, and corresponding repair measures are made in time. Therefore, the stress analysis, stress extraction, hypothetical crack, stress intensity factor output, crack mechanics analysis and other steps are automatically processed according to the actual operation of the nuclear power plant through the finite element modeling data, the fracture analysis is quickly completed, the weld defect evaluation result after the weld of the BOSS head is objectively output, the stability of the BOSS head in the refueling cycle or the entire service life of the nuclear power plant is determined, corresponding repair or replacement measures can be taken in time, technical support and protection for the safe operation of the nuclear power plant can be better provided, great losses caused by not taking measures in time can be reduced, and the operation economic benefit of the nuclear power plant is improved.

[0122] It should be understood that the size of the serial number of each step in the above embodiment does not mean the order of execution, and the execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the application.

[0123] In an embodiment, a BOSS head weld defect evaluation device for a nuclear power plant is provided, which corresponds to the BOSS head weld defect evaluation method for a nuclear power plant in the above embodiment. As shown in the figure, the BOSS head weld defect evaluation device for a nuclear power plant includes a receiving module 11, an intercepting module 12, an analyzing module 13, an evaluating module 14 and an outputting module 15. The functions of each module are described in detail as follows. Figure 7

[0124] ​The receiving module is configured to receive an evaluation request of a BOSS head after welding in a nuclear power plant, and obtain finite element modeling data, model constraint conditions and operation acquisition data associated with the BOSS head in the evaluation request.

[0125] The intercepting module is configured to determine an intercepting length according to a main pipe parameter in the finite element modeling data, and select a BOSS head region model from the finite element modeling data according to the intercepting length.

[0126] The analyzing module is configured to perform temperature field analysis, thermal stress analysis and mechanical load analysis on the BOSS head region model according to material parameters in the finite element modeling data, the model constraint conditions and the operation acquisition data, and obtain stress results.

[0127] The evaluating module is configured to perform fatigue crack propagation and stress corrosion crack propagation on the stress results by using a stress intensity factor analysis method, and obtain crack evaluation results.

[0128] The outputting module is configured to perform fracture analysis on the crack evaluation results, output a welding defect evaluation result corresponding to the BOSS head, and display corresponding repair measures according to the welding defect evaluation result.

[0129] The specific limitations of the BOSS head welding defect evaluation device for nuclear power plants can refer to the limitations of the BOSS head welding defect evaluation method for nuclear power plants described above, and will not be repeated here. Each module in the above BOSS head welding defect evaluation device for nuclear power plants can be realized by software, hardware and combinations thereof, in whole or in part. The above modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0130] In one embodiment, a computer device can be provided, which can be a terminal, and its internal structure diagram can be as shown in Figure 8 The computer device includes a processor, a memory, a network interface, a display screen and an input device connected by a system bus. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The network interface of the computer device is configured to communicate with an external server through a network connection. The computer program is executed by the processor to implement a BOSS head welding defect evaluation method for nuclear power plants.

[0131] In one embodiment, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the BOSS head weld defect evaluation method for nuclear power plants in the above embodiments when executing the computer program.

[0132] In one embodiment, a computer readable storage medium is provided, which stores a computer program, wherein the computer program is executed by a processor to implement the BOSS head weld defect evaluation method for nuclear power plants in the above embodiments.

[0133] Those skilled in the art can understand that all or part of the processes in the above embodiments can be completed by a computer program instructing related hardware, and the computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above embodiments. Any reference to memory, storage, database or other medium used in the embodiments provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0134] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is exemplified, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the above described functions.

[0135] The above-described embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for BOSS head weld defect assessment for nuclear power plants, characterized by, The method comprises the following steps: receiving an evaluation request of a BOSS head after welding in a nuclear power plant, obtaining finite element modeling data, model constraint conditions and operation acquisition data associated with the BOSS head to be evaluated in the evaluation request; determining a length of cutting according to a main pipeline parameter in the finite element modeling data, and selecting a BOSS head region model from the finite element modeling data according to the length of cutting; performing temperature field analysis, thermal stress analysis and mechanical load analysis on the BOSS head region model according to material parameters in the finite element modeling data, the model constraint conditions and the operation acquisition data, and obtaining stress results; performing fatigue crack propagation and stress corrosion crack propagation on the stress results by using a stress intensity factor analysis method, and obtaining crack evaluation results; performing fracture analysis on the crack evaluation results, outputting a welding defect evaluation result corresponding to the BOSS head to be evaluated, and displaying corresponding repair measures according to the welding defect evaluation result; the step of determining the length of cutting according to the main pipeline parameter in the finite element modeling data, and selecting the BOSS head region model from the finite element modeling data according to the length of cutting comprises the following steps: inputting a main pipeline radius mean value and a main pipeline wall thickness value into a length of cutting function, and calculating a minimum length by using the length of cutting function; the main pipeline parameter comprises the main pipeline radius mean value and the main pipeline wall thickness value; performing upward rounding on the minimum length to obtain the length of cutting; selecting the BOSS head region model from the finite element modeling data with a convergence center in the finite element modeling data as a center point and the length of cutting as a side length; the convergence center is an intersection point of a center axis of the main pipeline and a center axis of the BOSS head to be evaluated in the same plane.

2. The method for BOSS head weld defect evaluation for nuclear power plants according to claim 1, characterized by, the step of performing temperature field analysis, thermal stress analysis and mechanical load analysis on the BOSS head region model according to material parameters in the finite element modeling data, the model constraint conditions and the operation acquisition data, and obtaining stress results comprises the following steps: performing multi-dimensional structure unit division on the BOSS head region model according to the material parameters in the finite element modeling data and the model constraint conditions, and dividing out a temperature field model, a thermal stress field model and a mechanical load stress model; performing evaluation path identification on the temperature field model, the thermal stress field model and the mechanical load stress model, and identifying a plurality of evaluation paths; performing temperature field analysis, thermal stress analysis and mechanical load analysis on each of the evaluation paths according to the operation acquisition data, and obtaining transient temperature field curves, transient thermal stress curves and transient mechanical load stress curves corresponding to each of the evaluation paths; summarizing all the transient temperature field curves to obtain a transient temperature field distribution, summarizing all the transient thermal stress curves to obtain a transient thermal stress distribution, and summarizing all the transient mechanical load stress curves to obtain a transient mechanical load stress distribution; determining the transient temperature field distribution, the transient thermal stress distribution and the transient mechanical load stress distribution as the stress results.

3. The method for BOSS head weld defect evaluation for nuclear power plants as claimed in claim 2, characterized by, The multi-dimensional structure unit division is performed on the BOSS head region model according to the material parameters in the finite element modeling data and the model constraint conditions, and a temperature field model, a thermal stress field model and a mechanical load stress model are divided, including: According to the material parameters and the thermal stress model constraint conditions, first structure unit division and second structure unit division are respectively performed on the BOSS head region model, and a temperature field model and a thermal stress field model corresponding to the BOSS head region model are respectively obtained; the model constraint conditions include the thermal stress model constraint condition and the mechanical load model constraint condition; According to the material parameters and the mechanical load model constraint condition, third structure unit division is performed on the BOSS head region model, and a mechanical load stress model corresponding to the BOSS head region model is obtained.

4. The method for BOSS head weld defect evaluation for nuclear power plants as claimed in claim 2, characterized by, The evaluation path identification is performed on the temperature field model, the thermal stress field model and the mechanical load stress model, and a plurality of evaluation paths are identified, including: Path nodes in the temperature field model, the thermal stress field model and the mechanical load stress model are searched for coincidence and in a weld adjacent area of the BOSS head region model; Evaluation path rule detection is performed on all the path nodes, and a detection result is obtained; If the detection result is in line with the rule, the path nodes in line with the rule and adjacent are marked and distinguished, and the path nodes with the same mark are connected, and the evaluation path is obtained; If the detection result is not in line with the rule, the evaluation path is selected in a preset direction and a cross section in the weld adjacent area.

5. The method for BOSS head weld defect evaluation for nuclear power plants as claimed in claim 2, characterized by, According to the operation collection data, temperature field analysis, thermal stress analysis and mechanical load analysis are performed on each evaluation path, and transient temperature field curves, transient thermal stress curves and transient mechanical load stress curves corresponding to each evaluation path are obtained, including: Transient temperature field data of each evaluation path are obtained from a temperature field cloud diagram in the operation collection data, and temperature field analysis is performed on the transient temperature field data of each evaluation path, and the transient temperature field curves corresponding to each evaluation path are drawn; Transient thermal stress field data of each evaluation path are obtained from a thermal stress field cloud diagram in the operation collection data, and thermal stress analysis is performed on the transient thermal stress field data of each evaluation path, and the transient thermal stress field curves corresponding to each evaluation path are drawn; Transient mechanical load stress field data of each evaluation path are obtained from a mechanical load stress field cloud diagram in the operation collection data, and mechanical load analysis is performed on the transient mechanical load stress field data of each evaluation path, and the transient mechanical load stress curves corresponding to each evaluation path are drawn.

6. The method for BOSS head weld defect evaluation for nuclear power plants as claimed in claim 2, characterized by, The stress intensity factor analysis method is used to perform fatigue crack propagation and stress corrosion crack propagation on the stress result, and crack evaluation results are obtained, including: BOSS pipeline radius values and BOSS pipeline wall thickness values in the finite element modeling data are obtained; According to the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameter in the material parameters, a circumferential crack region and an axial crack region are identified; Polynomial fitting is performed on the transient temperature field distribution, the transient thermal stress distribution and the transient mechanical load stress distribution by using a stress intensity factor analysis method, and circumferential crack stress intensity factors and axial crack stress intensity factors are calculated through a stress intensity factor function; According to the BOSS pipe material parameter, the circumferential crack stress intensity factor and the axial crack stress intensity factor, fatigue crack propagation and stress corrosion crack propagation are performed on the circumferential crack region and the axial crack region respectively, and crack evaluation results are obtained.

7. The method for BOSS head weld defect evaluation for nuclear power plants as claimed in claim 6, characterized by, According to the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameter in the material parameters, a circumferential crack region and an axial crack region are identified, including: According to the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameter in the material parameters, circumferential crack parameters and semi-elliptical crack parameters matched therewith are obtained from a historical crack library; According to the circumferential crack parameters, a circumferential crack region with the minimum distance to all the evaluation paths is identified in the BOSS head region model; According to the semi-elliptical crack parameters, an axial crack region with the maximum intersection with all the evaluation paths is identified in the BOSS head region model.

8. The method for BOSS head weld defect evaluation for nuclear power plants as claimed in claim 6, characterized by, According to the circumferential crack stress intensity factor and the axial crack stress intensity factor, fatigue crack propagation and stress corrosion crack propagation are performed on the circumferential crack region and the axial crack region respectively, and crack evaluation results are obtained, including: According to the BOSS pipe material parameter and the circumferential crack stress intensity factor, circumferential fatigue crack propagation and circumferential stress corrosion crack propagation are performed on the circumferential crack region, and circumferential crack evaluation results are obtained; According to the BOSS pipe material parameter and the axial crack stress intensity factor, axial fatigue crack propagation and axial stress corrosion crack propagation are performed on the axial crack region, and axial crack evaluation results are obtained; The circumferential crack evaluation results and the axial crack evaluation results are determined as the crack evaluation results.

9. A BOSS head weld defect evaluation device for nuclear power plants, characterized by, including: The receiving module is configured to receive an evaluation request for a BOSS head after a weld seam in a nuclear power plant, and obtain finite element modeling data, model constraint conditions and operation acquisition data associated with the BOSS head in the evaluation request; The intercepting module is configured to determine an intercepting length according to a main pipe parameter in the finite element modeling data, and select a BOSS head region model from the finite element modeling data according to the intercepting length; The analysis module is configured to perform temperature field analysis, thermal stress analysis and mechanical load analysis on the BOSS head region model according to material parameters in the finite element modeling data, the model constraint conditions and the operation acquisition data, and obtain stress results; An evaluation module is configured to perform fatigue crack propagation and stress corrosion crack propagation on the stress results by using a stress intensity factor analysis method to obtain crack evaluation results; An output module is configured to perform fracture analysis on the crack evaluation results, output a weld defect evaluation result corresponding to the BOSS head to be evaluated, and display corresponding repair measures according to the weld defect evaluation result. The BOSS head region model is selected from the finite element modeling data according to the main pipeline parameter in the finite element modeling data, and the method comprises the following steps: The main pipeline radius mean value and the main pipeline wall thickness value are input into a cutting length function, and the shortest length is calculated by using the cutting length function; the main pipeline parameters include the main pipeline radius mean value and the main pipeline wall thickness value; The shortest length is rounded up to obtain the cutting length; The BOSS head region model is selected from the finite element modeling data with the confluence center as a center point and the cutting length as an edge length; the confluence center is an intersection point of the center axis of the main pipeline and the center axis of the BOSS head to be evaluated on the same plane.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to realize the steps of the BOSS head weld defect evaluation method for nuclear power plants according to any one of claims 1 to 8. 11.A computer readable storage medium, storing a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the BOSS head weld defect evaluation method for nuclear power plants according to any one of claims 1 to 8.

Images