Method, device, equipment and medium for evaluating axial defects of boss head welds for nuclear power plants

Abstract

The present application relates to the technical field of nuclear power plant detection, and discloses a BOSS head weld axial 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 in the nuclear power plant; determining the length to be intercepted and selecting a BOSS head area model; obtaining stress results and evaluation paths through temperature field analysis, thermal stress analysis and mechanical load analysis; identifying an axial crack area by using a BOSS head axial crack identification model, and performing axial fatigue crack propagation and axial stress corrosion crack propagation by using a stress intensity factor analysis method, so as to evaluate an axial crack evaluation result and output corresponding repair measures. The present application realizes automatic identification of the axial crack area and objective output of the weld defect evaluation result and measures.

Description

TECHNICAL FIELD

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

[0002] At present, the BOSS head weld structure (the parent pipe is opened, and the BOSS pipe is directly welded at the opening) is widely used in the pipeline system of the nuclear power plant. The welding of the BOSS head weld structure is mainly implemented by using the argon-electric combined welding process (manual argon arc welding for bottom welding, and stick electrode arc welding for filling and covering). For the BOSS head welded according to the welding process, 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 kind of inspection cannot detect the internal quality of the weld. However, the internal defects such as pores, cracks and incomplete fusion of the weld can easily become a failure source under the service environment of the high temperature and high pressure of the primary loop, thereby causing problems such as stress corrosion cracking of the BOSS head weld. When the axial defect of the BOSS head weld structure is found during the in-service period, the structural integrity evaluation is lacking, and therefore the stability of the BOSS head weld during the refueling period or the entire service life cannot be judged. SUMMARY

[0003] The present application provides a BOSS head weld axial defect evaluation method, device, equipment and medium for a nuclear power plant. The present application realizes automatic, rapid and objective fatigue crack propagation and stress corrosion crack propagation calculation from the axial dimension according to the actual operation of the nuclear power plant by finite element modeling, completes the axial crack evaluation result, and finally outputs the BOSS head weld defect evaluation result. Timely measures such as repair by digging and replacing can be taken, which can better provide technical support and protection for the safe operation of the nuclear power plant, reduce the huge loss caused by not taking timely measures, and improve the operation economic benefit of the nuclear power plant.

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

[0005] An evaluation request of a BOSS head to be evaluated in a nuclear power plant is received, and finite element modeling data, model constraint conditions and operation collection data associated with the BOSS head in the evaluation request are obtained. The BOSS head to be evaluated includes a parent pipe, a branch pipe connected to the parent pipe at a preset angle, and an annular weld area connected between the parent pipe and the branch pipe. The annular weld area is cut into a plurality of comparison blocks along the annular direction thereof;

[0006] According to the main pipeline parameters in the finite element modeling data, the length of the cut is determined, and the BOSS head area model is selected from the finite element modeling data according to the length of the cut;

[0007] According to the material parameters in the finite element modeling data, the model constraint conditions and the operation collection data, temperature field analysis, thermal stress analysis and mechanical load analysis are performed on the BOSS head region model to obtain stress results and multiple evaluation paths;

[0008] Axial crack parameters corresponding to each of the contrast blocks of the girth weld region of the BOSS head to be evaluated are obtained, the axial crack parameters and all the evaluation paths are input into the BOSS head axial crack identification model, the overlapping region between the axial crack parameters of each contrast block and each of the evaluation paths is identified by the BOSS head axial crack identification model, and the contrast block corresponding to the largest overlapping region is recorded as an axial crack region;

[0009] By using a stress intensity factor analysis method, axial fatigue crack propagation and axial stress corrosion crack propagation are performed on the stress results and the axial crack region to obtain axial crack evaluation results;

[0010] According to the axial crack evaluation results, repair measures corresponding to the axial crack evaluation results are output.

[0011] A BOSS head weld axial defect evaluation device for a nuclear power plant comprises:

[0012] A receiving module is configured to receive an evaluation request for a BOSS head to be evaluated in a nuclear power plant, and obtain finite element modeling data, model constraint conditions and operation collection data associated with the BOSS head in the evaluation request. The BOSS head to be evaluated comprises a main pipe, a branch pipe connected to the main pipe at a preset angle, and a girth weld region connected between the main pipe and the branch pipe. The girth weld region is cut into a plurality of contrast blocks along the girth direction thereof;

[0013] A cutting module is configured to determine a cutting length according to main pipe parameters in the finite element modeling data, and select a BOSS head region model from the finite element modeling data according to the cutting length.

[0014] 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 collection data, to obtain stress results and multiple evaluation paths.

[0015] An acquisition module is configured to acquire axial crack parameters corresponding to each of the contrast blocks of the girth weld area of the BOSS head to be evaluated, input the axial crack parameters and all the evaluation paths into the BOSS head axial crack identification model, identify the overlapping area between the axial crack parameters of each contrast block and each of the evaluation paths through the BOSS head axial crack identification model, and record the contrast block corresponding to the largest overlapping area as the axial crack area.

[0016] An evaluation module is configured to use a stress intensity factor analysis method to perform axial fatigue crack propagation and axial stress corrosion crack propagation on the stress results and the axial crack area, and obtain an axial crack evaluation result.

[0017] An output module is configured to output a repair measure corresponding to the axial crack evaluation result according to the axial crack evaluation result.

[0018] A computer device includes 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 girth weld axial defect evaluation method for nuclear power plants when executing the computer program.

[0019] A computer readable storage medium stores a computer program, and the computer program implements the steps of the BOSS head girth weld axial defect evaluation method for nuclear power plants when executed by a processor.

[0020] The application provides a BOSS head weld axial defect evaluation method, device, equipment and medium for nuclear power plants. The method comprises the following steps: receiving an evaluation request of a BOSS head to be evaluated in a nuclear power plant; obtaining finite element modeling data, model constraint conditions and operation collection data associated with the BOSS head in the evaluation request; the BOSS head to be evaluated comprises a main pipe, a branch pipe connected to the main pipe at a preset angle, and an annular weld area connected between the main pipe and the branch pipe; the annular weld area is cut into a plurality of contrast blocks along the annular direction thereof; determining an intercept length according to a main pipeline parameter 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 material parameters in the finite element modeling data, the model constraint conditions and the operation collection data, to obtain stress results and a plurality of evaluation paths; obtaining axial crack parameters corresponding to each contrast block of the annular weld area of the BOSS head to be evaluated, inputting the axial crack parameters and all the evaluation paths into a BOSS head axial crack identification model, identifying, by the BOSS head axial crack identification model, an overlapping area between the axial crack parameters of each contrast block and each evaluation path, and recording a contrast block corresponding to the largest overlapping area as an axial crack area; performing axial fatigue crack propagation and axial stress corrosion crack propagation on the stress results and the axial crack area by using a stress intensity factor analysis method, to obtain an axial crack evaluation result; and outputting a repair measure corresponding to the axial crack evaluation result according to the axial crack evaluation result.

[0021] Therefore, the application realizes automatic identification of the cutting length from the finite element modeling data, selection of the BOSS head area model, automatic output of stress results and multiple evaluation paths by using the temperature field analysis, thermal stress analysis and mechanical load analysis algorithms, automatic identification of the axial crack area by using the BOSS head axial crack identification model, automatic evaluation of the axial crack evaluation results by using the axial stress intensity factor analysis method, and automatic output of the weld defect evaluation results of the BOSS head to be evaluated by combining the additional crack evaluation results for timely making corresponding repair measures. Therefore, the application realizes the processing of stress analysis, stress extraction, assumed axial crack, axial stress intensity factor output and axial crack mechanical analysis according to the actual operation of the nuclear power plant by using the finite element modeling data, objectively outputs corresponding repair measures according to the axial crack evaluation results, determines the stability of the nuclear power plant during the refueling period or the entire service life of the nuclear power plant, can timely take corresponding repair or replacement measures, can better provide technical support and guarantee for the safe operation of the nuclear power plant, reduces huge losses caused by untimely measures, and improves the operation economic benefits of the nuclear power plant. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the application. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 is a schematic diagram of an application environment of the BOSS head weld axial defect evaluation method for the nuclear power plant in an embodiment of the application;

[0024] Figure 2 is a flowchart of the BOSS head weld axial defect evaluation method for the nuclear power plant in an embodiment of the application;

[0025] Figure 3 is a flowchart of step S20 of the BOSS head weld axial defect evaluation method for the nuclear power plant in an embodiment of the application;

[0026] Figure 4 is a flowchart of step S30 of the BOSS head weld axial defect evaluation method for the nuclear power plant in an embodiment of the application;

[0027] Figure 5 is a flowchart of step S302 of the BOSS head weld axial defect evaluation method for the nuclear power plant in an embodiment of the application;

[0028] Figure 6 is a flow chart of step S50 of the BOSS head weld axial defect evaluation method for nuclear power plants in an embodiment of the present application;

[0029] Figure 7 is a principle block diagram of the BOSS head weld axial defect evaluation device for nuclear power plants in an embodiment of the present application;

[0030] Figure 8 is a schematic diagram of the computer device in an embodiment of the present application. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] The BOSS head weld axial defect evaluation method for nuclear power plants provided by the present application can be applied in the application environment as shown in Figure 1 , wherein the client (computer device) communicates with the server through the 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 the 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.

[0033] In an embodiment, as shown in Figure 2 , a BOSS head weld axial defect evaluation method for nuclear power plants is provided, comprising the following steps S10-S60:

[0034] S10, receiving an evaluation request of a BOSS head to be evaluated 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; the BOSS head to be evaluated includes a main pipe, a branch pipe connected to the main pipe at a preset angle, and an annular weld area connected between the main pipe and the branch pipe; the annular weld area is cut into a plurality of contrast blocks along the annular direction thereof.

[0035] Understandably, in the pipeline applied in the operation in 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 adding branch pipes on the mother pipe, that is, the mother pipe opening, the BOSS pipeline (branch pipe) is directly welded at the opening, is connected on the mother pipe at a preset angle, the connection of the two pipelines is connected through the BOSS head, and the welding process mode of the BOSS head welding structure is used for welding connection in the annular welding seam area between the mother pipe and the branch pipe. For the completed BOSS head welding, the ANSYS simulation tool software is used to simulate the three-dimensional model of the finite element modeling of the BOSS head. 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. The annular welding seam area is the area of the annular welding seam of the welded BOSS head in the three-dimensional model of the finite element modeling. When it is necessary to evaluate the selected BOSS head 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 condition and the operation collection data associated with the BOSS head to be evaluated. The finite element modeling data is the data input in the process of establishing the finite element model and the data output in the process of establishing the 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 welding seam. The main pipeline parameter is a parameter related to the main pipeline connected with the BOSS head to be evaluated. The material parameter is a parameter related to the material of 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.

[0036] The ring weld area is cut into a plurality of contrast blocks along the ring direction thereof, the contrast blocks are a plurality of preset segments divided in the central axis direction of the ring weld area, and a plurality of the contrast blocks are uniformly cut in the ring direction of the ring weld area corresponding to each preset segment. The model constraint condition is a constraint condition or a rule constructed according to a demand of a thermal stress model or a constraint condition or a rule constructed according to a demand of a mechanical load model. The model constraint condition includes the thermal stress model constraint condition and the mechanical load model constraint condition. The thermal stress model constraint condition is a constraint condition or a rule for constructing a thermal stress model. The mechanical load model constraint condition is a constraint condition or a rule for constructing a mechanical load model. The operation collection data include 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 picture, a thermal stress field cloud picture and a mechanical load stress field cloud picture.

[0037] S20, determining a cutting length 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 cutting length.

[0038] Understandably, the main pipeline parameter includes 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 to the BOSS head to be evaluated. The main pipeline wall thickness value is a wall thickness of the main pipeline connected to the BOSS head to be evaluated. A cutting length function is used to calculate and output the cutting length. The cutting length is a length of the main pipeline in the three-dimensional model selected from the finite element modeling data. The main pipeline outside the cutting length is basically not affected by stress caused by a discontinuous effect after the BOSS head is connected. The BOSS head region model can be selected from the three-dimensional model through the cutting length. The BOSS head region model is a three-dimensional region of a cube with the cutting length as a side length selected from the three-dimensional model.

[0039] In an embodiment, as shown in Figure 3 The step S20, that is, determining a cutting length 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 cutting length, includes:

[0040] S201, inputting a main pipeline radius average value and a main pipeline wall thickness value into a cutting length function, and calculating a shortest length through the cutting length function. The main pipeline parameter includes the main pipeline radius average value and the main pipeline wall thickness value.

[0041] Understandably, the minimum length function is a function affected by the BOSS head access in the minimum length range summarized by the stress distribution collected by history, and the intercept length function is:

[0042]

[0043] Wherein,

[0044] L min is the minimum length;

[0045] R m is the average value of the main pipe radius, which is the average value of the outer diameter of the main pipe and the inner diameter of the main pipe;

[0046] t is the wall thickness value of the main pipe.

[0047] S202, rounding up the minimum length to obtain the intercept length.

[0048] Understandably, the minimum length usually has a decimal point, that is, a decimal value, and the minimum length needs to be rounded to facilitate the construction of the subsequent BOSS head region model temperature field model, thermal stress field model and mechanical load stress model, therefore, the minimum length is rounded up to obtain the intercept length.

[0049] S203, taking the convergence center in the finite element modeling data as the center point and the intercept length as the edge length, selecting the BOSS head region model from the finite element modeling data; 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.

[0050] Understandably, the convergence center in the finite element modeling data is the center of the cube, and the intercept length is the edge length of the cube, and the cube is selected from the finite element modeling data, 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.

[0051] The present application realizes that the mean value of the main pipe radius and the main pipe wall thickness value 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; the convergence center in the finite element modeling data is taken as the center point and the intercept length is taken as the edge length, the BOSS head area model is selected from the finite element modeling data, thus, the intercept length function is used to automatically obtain the intercept length, the BOSS head area model affected by the stress caused by the discontinuous effect after the BOSS head is accessed is scientifically and objectively intercepted through the intercept length, the construction temperature field model, the thermal stress field model and the mechanical load stress model of the subsequent intercepted BOSS head area model are facilitated, and the basic data for subsequent weld defect evaluation is provided.

[0052] S30, according to the material parameters in the finite element modeling data, the model constraint conditions and the operation collection data, temperature field analysis, thermal stress analysis and mechanical load analysis are performed on the BOSS head area model to obtain stress results and a plurality of evaluation paths.

[0053] Understandably, the material parameters are material-related parameters of the main pipe and the BOSS pipe, including main pipe material parameters and BOSS pipe material parameters, the main pipe material parameters are the material model of the main pipe, for example, the main pipe material parameters are X2 CrNi 19.10, X2 CrNi 19.10 is a model of stainless steel pipe, the BOSS pipe material parameters are the material model of the BOSS pipe, for example, the BOSS pipe material parameters are Z2 CND 18-12NC, Z2 CND 18-12NC is a model of stainless steel pipe for reactor coolant system piping, the model constraints are constraint conditions or rules constructed by the thermal stress model according to the demand or the constraint conditions or rules constructed by the mechanical load model, including the thermal stress model constraints and the mechanical load model constraints, the thermal stress model constraints are the constraint conditions or rules for constructing the thermal stress model, and the mechanical load model constraints are the constraint conditions or rules for constructing the mechanical load model, the operation collection data are the transient temperature data, thermal stress data and mechanical load stress data of the main pipe and the BOSS pipe at each time point collected in the historical operation process, including temperature field cloud picture, thermal stress field cloud picture and mechanical load stress field cloud picture, the temperature field cloud picture is the 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 the 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, and the mechanical load stress field cloud picture is the change distribution diagram of the mechanical load stress of the inner wall of each point in 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.

[0054] The temperature field analysis process involves obtaining transient temperature field data for each evaluation path from the temperature field cloud map in the operational data acquisition, and plotting the transient temperature field curve corresponding to each evaluation path. The thermal stress analysis process involves obtaining transient thermal stress field data for each evaluation path from the thermal stress field cloud map in the operational data acquisition, and plotting the transient thermal stress field curve corresponding to each evaluation path. The mechanical load analysis process involves obtaining transient mechanical load stress field data for each evaluation path from the mechanical load stress field cloud map in the operational data acquisition, and plotting the transient mechanical load stress curve corresponding to each evaluation path. The process of determining the mechanical load stress curve involves identifying the path after evaluation path recognition. This identification process involves finding a set of overlapping path nodes in the constructed temperature field model, thermal stress field model, and mechanical load stress model that are located in the weld proximity region. The weld proximity region is a three-dimensional area enclosed by a preset distance extended from the BOSS head welding point. All transient temperature field curves, transient thermal stress curves, and transient mechanical load stress curves are summarized to determine the stress result. The stress result reflects the stress distribution in dimensions such as temperature field, thermal stress field, and mechanical load stress field on each evaluation path.

[0055] In one embodiment, such as Figure 4 As shown, in step S30, namely, based on the material parameters in the finite element modeling data, the model constraints, and the operational data, temperature field analysis, thermal stress analysis, and mechanical load analysis are performed on the BOSS head region model to obtain stress results and multiple evaluation paths, including:

[0056] S301, based on the material parameters in the finite element modeling data and the model constraints, the BOSS head region model is divided into multi-dimensional structural units to form a temperature field model, a thermal stress field model, and a mechanical load stress model.

[0057] 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.

[0058] 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:

[0059] 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.

[0060] 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, and the second structure unit division is SOLID185 element division, the first structure unit division and the second structure unit division can be the same or different.

[0061] 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 main pipe and the BOSS pipe in the BOSS head region model are divided into different materials by using the SOLID185 unit division method, 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.

[0062] 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.

[0063] 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 as to splice the mechanical load stress model.

[0064] 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 different materials of the main pipeline and the BOSS pipeline, thereby providing a multi-dimensional data basis for subsequent BOSS head weld axial defect evaluation of the nuclear power plant and improving the accuracy and reliability of the evaluation.

[0065] S302, the temperature field model, the thermal stress field model and the mechanical load stress model are evaluated and identified to identify a plurality of evaluation paths.

[0066] 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.

[0067] 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 to identify a plurality of evaluation paths, which includes:

[0068] 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.

[0069] 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.

[0070] S3022, performing an evaluation path rule detection on all the path nodes to obtain a detection result.

[0071] 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 a preset number, and whether there are other path nodes within a 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.

[0072] 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.

[0073] S3024, if the detection result is the rule not meeting, the evaluation path is selected in the weld adjacent area according to a preset direction and a cross section.

[0074] 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 evaluation 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 requirements, 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.

[0075] 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; and if the detection result is the rule not meeting, the evaluation path is selected in the weld adjacent area according to a preset direction and a cross section, so that the evaluation path meeting the evaluation path rule is automatically selected, which provides a basis for subsequent extraction and analysis of stress results.

[0076] 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.

[0077] 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.

[0078] 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:

[0079] 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.

[0080] 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 when the temperature sharply drops from 345 degrees to 10 degrees at the 100th second, the temperature distribution when the temperature sharply rises 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 over time, the transient temperature field data refers to the data set of the transient temperature at each node of the evaluation path, and the transient temperature field data is a function of time and temperature coordinates, and reflects the temperature distribution over time.

[0081] 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.

[0082] 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 when the temperature sharply drops from 345 degrees to 10 degrees at the 100th second, the thermal stress distribution when the temperature sharply rises 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 over time, the transient thermal stress field data refers to the data set of the transient thermal stress at each node of the evaluation path, and the transient thermal stress field data is a function of time and thermal stress coordinates, and reflects the thermal stress distribution over time.

[0083] 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.

[0084] 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.

[0085] The step S3031, the step S3032 and the step S3033 can be executed in parallel or in series, and the order is not limited.

[0086] 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.

[0087] 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.

[0088] It can be understood that 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.

[0089] S305, determining the transient thermal stress distribution and the transient mechanical load stress distribution as the stress result.

[0090] 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, identifies a plurality of evaluation paths through evaluation path identification of the temperature field models, the thermal stress field models and the mechanical load stress models, performs temperature field analysis, thermal stress analysis and mechanical load analysis on each evaluation path according to the operation collection data to obtain 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, and determines the transient thermal stress distribution and the transient mechanical load stress distribution as the stress result, so that the temperature field models, the thermal stress field models and the mechanical load stress models are automatically divided through multi-dimensional structure unit division, the evaluation paths are automatically and scientifically identified quickly, the stress result of the temperature dimension, the thermal stress dimension and the mechanical load stress dimension is obtained through temperature field analysis, thermal stress analysis and mechanical load analysis, the cost of manually searching for the evaluation paths and analyzing and outputting the stress result is reduced, the efficiency is improved, and the accuracy and quality of the stress result output are improved.

[0091] S40, obtaining axial crack parameters corresponding to each of the contrast blocks of the girth weld region of the BOSS head to be evaluated, inputting the axial crack parameters and all the evaluation paths into the BOSS head axial crack identification model, identifying the overlapping region between the axial crack parameters of each contrast block and each of the evaluation paths through the BOSS head axial crack identification model, and recording the contrast block corresponding to the largest overlapping region as the axial crack region.

[0092] Understandably, the axial crack parameter is a parameter related to simulating or assuming that the contrast block has a crack, and the process of obtaining the axial crack parameter can be set according to requirements, such as the process of obtaining the axial crack parameter can be to obtain the parameters of the relevant crack matching the annular weld area of the to-be-evaluated BOSS head from a historical crack library, or by inputting the parameters of the estimated relevant crack detected from the field to obtain, etc., the BOSS head axial crack identification model is a model for identifying an axial crack area according to the axial crack parameter and all the evaluation paths, and the axial crack area is an area in which the worst block or a section of the annular crack is simulated in the axial dimension.

[0093] In an embodiment, in the step S40, that is, the axial crack parameters corresponding to each of the contrast blocks of the annular weld area of the to-be-evaluated BOSS head are obtained, the axial crack parameters and all the evaluation paths are input into the BOSS head axial crack identification model, the overlapping area between the axial crack parameter of each contrast block and each of the evaluation paths is identified by the BOSS head axial crack identification model, and the contrast block corresponding to the largest overlapping area is recorded as an axial crack area, comprising:

[0094] S401, obtaining the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameter in the finite element modeling data.

[0095] S402, performing crack simulation processing according to the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameter, to obtain the axial crack parameter of each contrast block.

[0096] Understandably, the crack simulation processing is to obtain the crack parameters matching the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameter from a historical crack library, the historical crack library stores crack parameters of block or semicircular cracks generated under different pipe wall thicknesses of different materials collected historically, and learns the correlation between the crack parameters and the BOSS pipe inner diameter, material and pipe wall thickness, so that the axial crack parameter matching the BOSS pipe radius value, the BOSS pipe wall thickness value and the BOSS pipe material parameter can be obtained from the historical crack library, the process of simulating or assuming the crack condition of the to-be-evaluated BOSS head according to the historical data collected in the historical crack library, simulating the axial block or semicircular crack of the to-be-evaluated BOSS head, and evaluating the defect through the simulated annular crack and semicircular crack can improve the accuracy and reliability of the evaluation.

[0097] The axial crack parameter is a relevant parameter of a block-shaped or non-closed annular or half-annular crack, and the axial crack parameter includes a depth of the axial crack and a width of the axial crack, and the depth of the axial crack is three times the width of the axial crack.

[0098] S403, input the axial crack parameter and all the evaluation paths into the BOSS head axial crack identification model.

[0099] S404, determine, by the BOSS head axial crack identification model, a coincidence area between the axial crack parameter of each comparison block and each evaluation path.

[0100] Understandably, the determined process is to output a plurality of axial crack simulation areas of each comparison block according to the axial crack parameter of each comparison block, the axial crack simulation area is a region where a crack occurs in the corresponding comparison block, since the region can be distributed in different positions of the comparison block, therefore, calculate the volume of the intersection between each axial crack simulation area of the same comparison block and each evaluation path, find the maximum volume in the volume of the intersection between each axial crack simulation area of the same comparison block and each evaluation path, and record the axial crack simulation area corresponding to the maximum volume as the coincidence area between the axial crack parameter of the comparison block and each evaluation path.

[0101] In an embodiment, the step S404, i.e., the determination of the coincidence area between the axial crack parameter of each comparison block and each evaluation path by the BOSS head axial crack identification model, includes:

[0102] S4041, simulate and output, by the BOSS head axial crack identification model, a plurality of axial crack simulation areas of each comparison block according to the axial crack parameter of each comparison block.

[0103] Understandably, according to the axial crack parameter of one comparison block, the region surrounded by the axial crack parameter is moved in different positions in the comparison block, i.e., in the comparison block, each time a step is moved, an axial crack simulation area is output.

[0104] S4042, calculate, by the BOSS head axial crack identification model, the volume of the intersection between each axial crack simulation area of the same comparison block and each evaluation path.

[0105] Understandably, the volume of the intersection between the axial crack simulation area of the same comparison block and each evaluation path is calculated.

[0106] S4043, obtaining the maximum volume of the intersection volume between each of the axial crack simulation regions of the same comparison block and each of the evaluation paths through the BOSS head axial crack identification model, and recording the axial crack simulation region corresponding to the maximum volume as the overlapping region between the axial crack parameter of the comparison block and each of the evaluation paths.

[0107] The present application realizes that the BOSS head axial crack identification model can automatically identify the overlapping region between the axial crack parameter of each comparison block and each of the evaluation paths, and provides accurate simulation data for subsequent determination of the axial crack region, thereby improving the accuracy of subsequent crack evaluation.

[0108] S405, calculating the volume of each of the overlapping regions through the BOSS head axial crack identification model, sorting the volume of all the overlapping regions, obtaining the overlapping region with the largest volume, and recording the overlapping region as the axial crack region.

[0109] It can be understood that the volume of all the overlapping regions is sorted in descending order, and the first one in the sorted order is the overlapping region with the largest volume, which is recorded as the axial crack region.

[0110] The present application realizes that the BOSS head axial crack identification model can automatically identify the overlapping region between the axial crack parameter of each comparison block and each of the evaluation paths, and provides accurate simulation data for subsequent determination of the axial crack region, thereby improving the accuracy of subsequent crack evaluation.

[0108] S405, calculating the volume of each of the overlapping regions through the BOSS head axial crack identification model, sorting the volume of all the overlapping regions, obtaining the overlapping region with the largest volume, and recording the overlapping region as the axial crack region.

[0109] It can be understood that the volume of all the overlapping regions is sorted in descending order, and the first one in the sorted order is the overlapping region with the largest volume, which is recorded as the axial crack region.

[0110] The present application realizes that the BOSS head axial crack identification model can automatically identify the overlapping region between the axial crack parameter of each comparison block and each of the evaluation paths, and provides accurate simulation data for subsequent determination of the axial crack region, thereby improving the accuracy of subsequent crack evaluation.

[0111] S50, using a stress intensity factor analysis method, performing axial fatigue crack propagation and axial stress corrosion crack propagation on the stress result and the axial crack region to obtain an axial crack evaluation result.

[0112] Understandably, the stress intensity factor analysis method is a method of performing polynomial fitting on the stress perpendicular to the crack surface from the BOSS pipe wall thickness at the position of the crack, and then using a stress intensity factor function to calculate the stress intensity factor of the axial crack region. The axial fatigue crack propagation is an expansion method of estimating crack fatigue life according to a fatigue crack propagation rate in the axial crack region. The axial fatigue propagation rate is related to the BOSS pipe material parameters and the stress intensity factor. The axial stress corrosion crack propagation is an expansion method of estimating crack corrosion life according to a stress corrosion expansion rate in the axial crack region. The axial stress corrosion crack propagation rate is related to the BOSS pipe material parameters and the stress intensity factor. The axial fatigue crack propagation and the axial stress corrosion crack propagation on the axial crack region obtain the axial crack evaluation result, which reflects the evaluation result of the crack propagation in the axial crack region.

[0113] The stress intensity factor function is a calculation formula of the stress intensity factor in fracture mechanics.

[0114] In an example, as shown in Figure 6 The step S50, that is, using the stress intensity factor analysis method, performing axial fatigue crack propagation and axial stress corrosion crack propagation on the stress result and the axial crack region to obtain an axial crack evaluation result, includes:

[0115] S501, obtaining the BOSS pipe material parameters in the material parameters and the axial crack region.

[0116] Understandably, the process of identifying the circumferential crack region is a process of detecting the distance of each node on the outer surface of the circumferential crack region from each all evaluation path to be optimal in the BOSS head region model according to the circumferential crack parameters. The process of identifying the axial crack region is a process of detecting the intersection of the axial crack region with all the evaluation paths to be maximum in the BOSS head region model according to the semi-elliptical crack parameters.

[0117] S502, using a stress intensity factor analysis method, performing polynomial fitting on the stress result and the axial crack region to obtain an axial crack evaluation result.

[0118] 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 axial crack area by using the stress intensity factor function. The process of polynomial fitting on the transient thermal stress distribution and the transient mechanical load stress distribution is that according to the transient thermal stress field distribution combined with the axial crack area, the thermal stress results of 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 axial crack area, the mechanical load stress results of the axial crack area can be respectively output by the ANSYS simulation tool software, the axial crack stress intensity factor is obtained by using the stress intensity factor function, multiplying and summing the respective weighting factors of the axial crack area thermal stress results and the mechanical load stress results, and then taking the integral and multiplying with a is the crack depth of the axial crack.

[0119] S503, according to the BOSS pipe material parameters and the axial crack stress intensity factor, the axial fatigue crack propagation and the axial stress corrosion crack propagation are carried out in the axial crack area, and the axial crack evaluation result is obtained.

[0120] Understandably, the axial fatigue crack propagation is an expansion method of estimating crack fatigue life according to the fatigue crack propagation rate in the axial crack area, the axial fatigue propagation rate is related to the BOSS pipe material parameters and the stress intensity factor, the axial stress corrosion crack propagation is an expansion method of estimating crack corrosion life according to the stress corrosion expansion rate in the axial crack area, the axial stress corrosion crack propagation rate is related to the BOSS pipe material parameters and the stress intensity factor, the axial fatigue crack propagation and the axial stress corrosion crack propagation are carried out in the axial crack area, and the axial crack evaluation result is obtained. The axial crack evaluation result reflects the evaluation result of crack propagation in the axial crack area.

[0121] 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 axial crack area.

[0122] The application realizes automatic identification of the axial crack area, calculation of the axial crack stress intensity factor by using the stress intensity factor analysis method, and output of the crack evaluation result, can scientifically, objectively and quickly output the crack evaluation result of the crack expansion of the axial crack area every year, provides a method for evaluating the crack expansion result from the axial dimension of the BOSS head weld defect, can better provide technical support and guarantee for the safe operation of the nuclear power plant, reduces the huge loss caused by not taking timely measures, and improves the operation economic benefit of the nuclear power plant.

[0123] S60, output the repair measures corresponding to the axial crack evaluation result according to the axial crack evaluation result.

[0124] Understandably, the axial crack evaluation result is subjected to fracture analysis, and the analysis process is to judge the annual evaluation result of each factor in the axial crack evaluation result, for example: if the initial axial crack length is 5mm, the crack depth is 14.4962mm at the end of the 9th year, the stress intensity factor is less than the material toughness, and 14.4962mm has exceeded 0.75 times (17.8x0.75=13.35mm) of the BOSS pipe wall thickness (17.8mm), the structure will exist the failure of plastic collapse, and the coolant leakage risk will occur, whether the failure occurs in the preset year is judged according to the axial crack evaluation result, the corresponding repair measures are output combined with the result of fracture analysis, the repair measures include the year when the BOSS head to be evaluated needs to be repaired or replaced, and the repair measures are displayed.

[0125] Among them, the additional crack evaluation result and the axial crack evaluation result in the crack evaluation result are comprehensively analyzed, the length and depth ratio of crack expansion at the same time point and the year when the fracture occurs are compared, the weld defect evaluation result of the BOSS head to be evaluated is output, and the measures of the year when the BOSS head to be evaluated needs to be repaired or replaced are displayed according to the weld defect evaluation result.

[0126] The application realizes the following steps: receiving an evaluation request of a BOSS head to be evaluated in a nuclear power plant, obtaining finite element modeling data, model constraint conditions and operation collection data associated with the BOSS head in the evaluation request; the BOSS head to be evaluated includes a main pipe, a branch pipe connected to the main pipe at a preset angle, and an annular weld area connected between the main pipe and the branch pipe; the annular weld area is cut into a plurality of contrast blocks along the annular direction thereof; 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; 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, obtaining stress results and a plurality of evaluation paths; obtaining axial crack parameters corresponding to each of the contrast blocks of the annular weld area of the BOSS head to be evaluated, inputting the axial crack parameters and all the evaluation paths into a BOSS head axial crack identification model, identifying an overlapping area between the axial crack parameters of each contrast block and each of the evaluation paths through the BOSS head axial crack identification model, and recording a contrast block corresponding to the largest overlapping area as an axial crack area; using a stress intensity factor analysis method, performing axial fatigue crack propagation and axial stress corrosion crack propagation on the stress results and the axial crack area, obtaining an axial crack evaluation result; outputting a repair measure corresponding to the axial crack evaluation result according to the axial crack evaluation result, which realizes automatic identification of the length of cutting and selection of the BOSS head area model from the finite element modeling data, automatic output of the stress results and the plurality of evaluation paths by using the algorithms of the temperature field analysis, the thermal stress analysis and the mechanical load analysis, automatic identification of the axial crack area by using the BOSS head axial crack identification model, automatic evaluation of the axial crack evaluation result by using the axial stress intensity factor analysis method, and fracture analysis by combining the additional crack evaluation result to output a weld defect evaluation result of the BOSS head to be evaluated and make a corresponding repair measure in time, so that the stress analysis, stress extraction, assumed axial crack, axial stress intensity factor output, axial crack mechanical analysis and other steps are automatically processed according to the actual operation of the nuclear power plant through the finite element modeling data, the corresponding repair measure is objectively output according to the axial crack evaluation result, the stability of the nuclear power plant during the refueling period or the entire service life of the nuclear power plant is determined, corresponding measures such as repair by excavation or replacement 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 economic benefits of the operation of the nuclear power plant are improved.

[0127] It should be understood that the size of the serial number of each step in the above embodiments does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0128] In an embodiment, a BOSS head weld axial defect evaluation device for a nuclear power plant is provided, which corresponds to the BOSS head weld axial defect evaluation method for a nuclear power plant in the above embodiment. As shown in the figure, the BOSS head weld axial defect evaluation device for a nuclear power plant includes a receiving module 11, an intercepting module 12, an analyzing module 13, an obtaining module 14, an evaluation module 15 and an output module 16. The detailed description of each functional module is as follows: Figure 7

[0129] The receiving module 11 is configured to receive an evaluation request of a BOSS head to be evaluated in a nuclear power plant, obtain finite element modeling data, model constraint conditions and operation acquisition data associated with the BOSS head in the evaluation request; the BOSS head to be evaluated includes a main pipe, a branch pipe connected to the main pipe at a preset angle, and an annular weld area connected between the main pipe and the branch pipe; the annular weld area is cut into a plurality of comparison blocks along the annular direction thereof;

[0130] The intercepting module 12 is configured to determine an intercepting length according to a main pipe parameter in the finite element modeling data, and select a BOSS head area model from the finite element modeling data according to the intercepting length;

[0131] The analyzing module 13 is configured to perform 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 acquisition data, to obtain stress results and a plurality of evaluation paths;

[0132] The obtaining module 14 is configured to obtain axial crack parameters corresponding to each comparison block of the annular weld area of the BOSS head to be evaluated, input the axial crack parameters and all the evaluation paths into the BOSS head axial crack identification model, identify the overlapping area between the axial crack parameters of each comparison block and each evaluation path through the BOSS head axial crack identification model, and record the comparison block corresponding to the largest overlapping area as an axial crack area;

[0133] The evaluation module 15 is configured to perform axial fatigue crack propagation and axial stress corrosion crack propagation on the stress results and the axial crack area by using a stress intensity factor analysis method, to obtain an axial crack evaluation result;

[0134] ​The output module 16 is configured to output a repair measure corresponding to the axial crack evaluation result according to the axial crack evaluation result.

[0135] The specific limitations of the BOSS head weld axial defect evaluation device for nuclear power plants can refer to the limitations of the BOSS head weld axial defect evaluation method for nuclear power plants described above, and will not be repeated here. Each module in the BOSS head weld axial defect evaluation device for nuclear power plants described above can be realized by software, hardware, and combinations thereof, in whole or in part. The above-mentioned 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 as to be called and executed by the processor to perform the operations corresponding to each of the above modules.

[0136] In one embodiment, a computer device, which can be a terminal, is provided, and an internal structure diagram of the computer device 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 through 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 weld axial defect evaluation method for nuclear power plants.

[0137] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the BOSS head weld axial defect evaluation method for nuclear power plants in the above-mentioned embodiments when executing the computer program.

[0138] In one embodiment, a computer readable storage medium is provided, and the computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the BOSS head weld axial defect evaluation method for nuclear power plants in the above-mentioned embodiments.

[0139] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. 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.

[0140] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of functional units and modules is exemplified, and in actual application, the above-mentioned 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.

[0141] The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; 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 axial flaw evaluation for nuclear power plants, characterized by, The method comprises the following steps: receiving an evaluation request of a BOSS head to be evaluated 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; the BOSS head to be evaluated comprises a main pipe, a branch pipe connected to the main pipe at a preset angle, and an annular weld area connected between the main pipe and the branch pipe; the annular weld area is cut into a plurality of contrast blocks along the annular direction thereof; 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; 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 acquisition data, to obtain stress results and a plurality of evaluation paths; obtaining axial crack parameters corresponding to each of the contrast blocks of the annular weld area of the BOSS head to be evaluated, inputting the axial crack parameters and all the evaluation paths into a BOSS head axial crack identification model, identifying an overlapping area between the axial crack parameters of each contrast block and each of the evaluation paths through the BOSS head axial crack identification model, and recording a contrast block corresponding to a largest overlapping area as an axial crack area; performing axial fatigue crack propagation and axial stress corrosion crack propagation on the stress results and the axial crack area by using a stress intensity factor analysis method, to obtain an axial crack evaluation result; outputting a repair measure corresponding to the axial crack evaluation result according to the axial crack evaluation result.

2. The method for BOSS head weld axial flaw evaluation for nuclear power plants as claimed in claim 1, characterized in that, The method of determining the length of cutting according to the main pipe parameter in the finite element modeling data, and selecting the BOSS head area model from the finite element modeling data according to the length of cutting comprises the following steps: inputting a mean value of a main pipe radius and a main pipe wall thickness value into a length of cutting function, and calculating a shortest length through the length of cutting function; the main pipe parameter comprises the mean value of the main pipe radius and the main pipe wall thickness value; performing upward rounding on the shortest length to obtain the length of cutting; selecting the BOSS head area model from the finite element modeling data with a center of convergence in the finite element modeling data as a center point and the length of cutting as a side length; the center of convergence is an intersection point of a center axis of the main pipe and a center axis of the BOSS head to be evaluated in the same plane.

3. The method for BOSS head weld axial flaw evaluation for nuclear power plants as claimed in claim 1, characterized in that, The method of 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 acquisition data, to obtain stress results and a plurality of evaluation paths, comprises the following steps: performing multi-dimensional structure unit division on the BOSS head area model according to the material parameters in the finite element modeling data and the model constraint conditions, to divide 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, to identify a plurality of the evaluation paths; According to the operation acquisition data, temperature field analysis, thermal stress analysis and mechanical load analysis are performed on each of the evaluation paths, to obtain transient temperature field curves, transient thermal stress curves and transient mechanical load stress curves corresponding to each of the evaluation paths; 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; The transient thermal stress distribution and the transient mechanical load stress distribution are determined as the stress results.

4. The method for BOSS head weld axial flaw evaluation for nuclear power plants as claimed in claim 3, characterized in that, The multi-dimensional structure element 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, to divide a temperature field model, a thermal stress field model and a mechanical load stress model, including: According to the material parameters and the thermal stress model constraint conditions, first structure element division and second structure element division are respectively performed on the BOSS head region model, to obtain a temperature field model and a thermal stress field model corresponding to the BOSS head region model; the model constraint conditions include the thermal stress model constraint conditions and the mechanical load model constraint conditions; According to the material parameters and the mechanical load model constraint conditions, third structure element division is performed on the BOSS head region model, to obtain a mechanical load stress model corresponding to the BOSS head region model.

5. The method for BOSS head weld axial flaw evaluation for nuclear power plants as claimed in claim 3, wherein, The evaluation path identification is performed on the temperature field model, the thermal stress field model and the mechanical load stress model, to identify a plurality of evaluation paths, including: Path nodes that are coincident and located in a weld seam adjacent region of the BOSS head region model are found in the temperature field model, the thermal stress field model and the mechanical load stress model; Evaluation path rule detection is performed on all the path nodes, to obtain a detection result; If the detection result is in line with the rule, the path nodes that are in line with the rule and adjacent are marked and distinguished, and the path nodes with the same mark are connected, to obtain the evaluation paths; If the detection result is not in line with the rule, the evaluation paths are selected in a preset direction and cross section in the weld seam adjacent region.

6. The method for BOSS head weld axial flaw evaluation for nuclear power plants as claimed in claim 3, wherein, According to the operation acquisition data, temperature field analysis, thermal stress analysis and mechanical load analysis are performed on each of the evaluation paths, to obtain transient temperature field curves, transient thermal stress curves and transient mechanical load stress curves corresponding to each of the evaluation paths, including: Transient temperature field data of each of the evaluation paths is obtained from a temperature field cloud chart in the operation acquisition data, and temperature field analysis is performed on the transient temperature field data of each of the evaluation paths, to draw the transient temperature field curves corresponding to each of the evaluation paths; Transient thermal stress field data of each of the evaluation paths is obtained from a thermal stress field cloud chart in the operation acquisition data, and thermal stress analysis is performed on the transient thermal stress field data of each of the evaluation paths, to draw the transient thermal stress field curves corresponding to each of the evaluation paths; The transient mechanical load stress field data of each evaluation path is obtained from the mechanical load stress field cloud chart in the operation collected data, and the transient mechanical load stress field data of each evaluation path is subjected to mechanical load analysis to depict the transient mechanical load stress curve corresponding to each evaluation path.

7. The method for BOSS head weld axial flaw evaluation for nuclear power plants as claimed in claim 3, wherein, The stress intensity factor analysis method is used to perform axial fatigue crack propagation and axial stress corrosion crack propagation on the stress result and the axial crack region to obtain an axial crack evaluation result, including: The BOSS pipe material parameters in the material parameters and the axial crack region are obtained; The stress intensity factor analysis method is used to perform polynomial fitting on the transient thermal stress distribution and the transient mechanical load stress distribution, and the axial crack stress intensity factor is calculated through an axial stress intensity factor function; According to the BOSS pipe material parameters and the axial crack stress intensity factor, the axial fatigue crack propagation and the axial stress corrosion crack propagation are performed on the axial crack region to obtain an axial crack evaluation result.

8. The method for BOSS head weld axial flaw evaluation for nuclear power plants as claimed in claim 1, wherein, The axial crack parameters corresponding to each of the comparison blocks of the annular weld region of the BOSS head to be evaluated are obtained, the axial crack parameters and all the evaluation paths are input into the BOSS head axial crack identification model, the overlapping region between the axial crack parameters of each comparison block and each evaluation path is identified through the BOSS head axial crack identification model, and the comparison block corresponding to the largest overlapping region is recorded as the axial crack region, including: The BOSS pipe radius value, the BOSS pipe wall thickness value, and the BOSS pipe material parameters 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 parameters, crack simulation processing is performed to obtain the axial crack parameters of each comparison block; The axial crack parameters and all the evaluation paths are input into the BOSS head axial crack identification model; The overlapping region between the axial crack parameters of each comparison block and each evaluation path is determined through the BOSS head axial crack identification model; The volume of each overlapping region is calculated through the BOSS head axial crack identification model, the volumes of all the overlapping regions are sorted, the largest volume overlapping region is obtained, and the overlapping region is recorded as the axial crack region.

9. The method for BOSS head weld axial flaw evaluation for nuclear power plants as claimed in claim 8, characterized in that, The overlapping region between the axial crack parameters of each comparison block and each evaluation path is determined through the BOSS head axial crack identification model, including: A plurality of axial crack simulation regions of each comparison block are simulated and output through the BOSS head axial crack identification model according to the axial crack parameters of each comparison block; The volume of the intersection between each axial crack simulation region of the same comparison block and each evaluation path is calculated through the BOSS head axial crack identification model; The maximum volume in the volume of intersection between each axial crack simulation region of the same comparison block and each evaluation path is obtained through the BOSS head axial crack identification model, and the axial crack simulation region corresponding to the maximum volume is recorded as the overlapping region between the axial crack parameter of the comparison block and each evaluation path.

10. A BOSS head weld axial flaw evaluation device for nuclear power plants, characterized by, Comprise: The receiving module is used for receiving an evaluation request of a BOSS head to be evaluated 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; the BOSS head to be evaluated comprises a main pipe, a branch pipe connected to the main pipe at a preset angle, and an annular weld region connected between the main pipe and the branch pipe; the annular weld region is cut into a plurality of comparison blocks along the annular direction thereof; The intercepting module is used for determining an intercepting length 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 intercepting length; The analysis module is used for 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, obtaining stress results and a plurality of evaluation paths; The obtaining module is used for obtaining axial crack parameters corresponding to each comparison block of the annular weld region of the BOSS head to be evaluated, inputting the axial crack parameters and all the evaluation paths into the BOSS head axial crack identification model, identifying the overlapping region between the axial crack parameter of each comparison block and each evaluation path through the BOSS head axial crack identification model, and recording the comparison block corresponding to the largest overlapping region as an axial crack region; The evaluation module is used for performing axial fatigue crack propagation and axial stress corrosion crack propagation on the stress results and the axial crack region by using a stress intensity factor analysis method, obtaining an axial crack evaluation result; The output module is used for outputting a repair measure corresponding to the axial crack evaluation result according to the axial crack evaluation result.

11. 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 axial defect evaluation method for a nuclear power plant according to any one of claims 1 to 9.

12. A computer-readable storage medium, the 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 axial defect evaluation method for a nuclear power plant according to any one of claims 1 to 9.

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