An on-line stress calculation method, electronic device and storage medium for steam turbine pipelines

Abstract

A method for on-line stress calculation of steam turbine pipelines, an electronic device and a storage medium, belonging to the technical field of stress calculation of steam turbine pipelines. To solve the problems of real-time stress calculation and convenient configuration of steam turbine pipelines. The present invention extracts steam turbine pipeline data, constructs a spatial beam element finite element model of the steam turbine pipeline, collects on-site operation data of the steam turbine, collects cylinder material data of the steam turbine, calculates cylinder interface displacement data of the steam turbine, inputs the collected node displacement data of the steam turbine pipeline into the constructed spatial beam element finite element model, inputs node information data and element information data to obtain parameter settings for the spatial beam element; corrects the node displacements of the obtained spatial beam element and adds constraint conditions for the spatial beam element; uses the feon library to construct the mass matrix and stiffness matrix of the spatial beam element, establishes a solver for solution, and calculates the maximum normal stress of the nodes of the steam turbine pipeline. The present invention is used for calculating real-time stress.

Description

Technical Field

[0001] The present invention belongs to the technical field of stress calculation of steam turbine pipelines, and particularly relates to an on-line stress calculation method, an electronic device and a storage medium for steam turbine pipelines. Background Art

[0002] The working environment of steam turbine pipelines is complex, and they work under high temperature and high pressure for a long time. The damage of steam turbine pipelines will cause serious safety accidents and economic losses to power plants, so it is very important to assess their stress states. In recent years, the demand for peak shaving of steam turbine units has been increasing. The frequent variable working conditions and start-up and shutdown of steam turbine units will cause the stress fluctuations of steam turbine pipelines to become faster. The design life calculation of manufacturers only assesses normal cold start and hot start, and does not conduct in-depth research on steam turbine pipelines under variable working conditions. The existing calculation methods for steam turbine pipelines mainly focus on strength calculation during the product design process. The input data is the stable working condition data of steam turbine units, which is not real-time and has a long calculation time, and cannot meet the urgent need for real-time calculation in power plants. Summary of the Invention

[0003] The problem to be solved by the present invention is to propose an on-line stress calculation method, an electronic device and a storage medium for steam turbine pipelines aiming at the problems of real-time stress calculation and convenient configuration of steam turbine pipelines.

[0004] To achieve the above object, the present invention is realized through the following technical solutions:

[0005] An on-line stress calculation method for steam turbine pipelines includes the following steps:

[0006] S1. Extract steam turbine pipeline data according to the CAD drawings of the steam turbine pipeline, including the spatial position data of the steam turbine pipeline, the node data of the steam turbine pipeline, the corner radius data of the steam turbine pipeline, and the interface position data of the steam turbine pipeline;

[0007] S2. Use the steam turbine pipeline data obtained in step S1 to construct a spatial beam element finite element model of the steam turbine pipeline, and set the node information data format and element information data format of the spatial beam element finite element model;

[0008] S3. Collect the on-site operation data of the steam turbine, including the node displacement data at the measuring points of the steam turbine pipeline and the operation data of the steam turbine. The operation data of the steam turbine includes the cylinder end displacement measurement data of the steam turbine, the cylinder temperature measurement data of the steam turbine, the steam inlet temperature data of the steam turbine pipeline, and the steam inlet pressure data of the steam turbine pipeline, for later use;

[0009] S4. Collect the cylinder material data of the steam turbine, and then calculate the elastic modulus and linear expansion coefficient of the cylinder material of the steam turbine at different temperatures, for later use;

[0010] S5. Calculate the cylinder interface displacement data of the steam turbine based on the operating data of the steam turbine collected in step S3 and the cylinder material data of the steam turbine obtained in step S4.

[0011] S6. Input the node displacement data at the measuring points of the steam turbine pipeline collected in step S3 into the spatial beam element finite element model constructed in step S2, input the node information data and element information data, and obtain the parameter settings for the spatial beam element.

[0012] S7. Correct the node displacements of the spatial beam element obtained in step S6 and add the constraint conditions of the spatial beam element.

[0013] S8. Use the feon library to construct the mass matrix and stiffness matrix of the spatial beam element obtained in step S6, establish a solver to solve the spatial beam element finite element model, obtain the node displacements and node element forces of the steam turbine pipeline, and then calculate the maximum normal stress of the nodes of the steam turbine pipeline.

[0014] S9. Repeat steps S3 - S8 to calculate the online stress of the steam turbine pipeline.

[0015] Further, the specific implementation method of step S1 is to set the spatial position of the steam turbine pipeline with the starting interface of the steam turbine pipeline as the origin, and sequentially extract the spatial coordinate data of the turning and bending points of the steam turbine pipeline, the turning radius data of the steam turbine pipeline, the inner diameter data and outer diameter data of the steam turbine pipeline, and the position coordinate data of the steam turbine pipeline until the end of the steam turbine pipeline.

[0016] Further, the specific implementation method of step S2 includes the following steps:

[0017] S2.1. Use the python package of Abaqus to generate the elements and meshes for finite element calculation, read the position coordinate data of the steam turbine pipeline to generate point coordinates, connect the point coordinates into lines in sequence, and generate the steam turbine pipeline curve according to the turning radius data of the steam turbine pipeline.

[0018] S2.2. Perform mesh division on the steam turbine pipeline curve generated in step S2.1, and set the mesh division parameters as size, deviationFactor, and minSizeFactor, where size represents the size, and the value range is 0.04 - 0.06, deviationFactor represents the size deviation coefficient, and the value range is 0.05 - 0.2, and minSizeFactor represents the minimum size coefficient, and the value range is 0.05 - 0.2.

[0019] S2.3. Output the meshes divided in step S2.2, select the space beam elements. The data format of the output node information is: node number, node X coordinate, node Y coordinate, node Z coordinate. The data format of the output element information is element number, front node number, rear node number. At the same time, mark the nodes at the interfaces of the generated space beam elements, the nodes at the supports and hangers, and the nodes at the measuring points.

[0020] Further, the specific implementation method of step S4 is that the collected cylinder material data of the steam turbine are the elastic modulus and linear expansion coefficient of the cylinder material of the steam turbine at temperatures of 100°, 200°, 300°, 400°, 500°, and 600°. Then, the linear extrapolation interpolation method is used to calculate the elastic modulus E and linear expansion coefficient of the cylinder material of the steam turbine at different temperatures.

[0021] Further, the calculation formula for the cylinder interface displacement data of the steam turbine in step S5 is:

[0022] X 接口 = X 汽缸端部位移 -(T 汽缸 - 20)×(1 + α)×x s

[0023] Y 接口 = (T 汽缸 - 20)×(1 + α)×y s

[0024] Z 接口 = (T 汽缸 - 20)×(1 + α)×z s

[0025] Wherein, X 接口 , Y 接口 , Z 接口 are the displacements of the steam turbine cylinder interface in the X, Y, and Z directions. X 汽缸端部位移 is the displacement of the cylinder end in the X direction in the steam turbine safety monitoring system data. T 汽缸 is the temperature of the cylinder metal material in the steam turbine safety monitoring system data. α is the linear expansion coefficient of the cylinder metal material at temperature T 汽缸 . x s is the distance of the steam turbine cylinder interface from the cylinder end in the X direction. y s is the distance of the steam turbine cylinder interface from the turbine foundation surface in the Y direction. z s is the distance of the steam turbine cylinder interface from the center line of the turbine rotor axis in the Z direction.

[0026] Further, the specific implementation method of step S6 includes the following steps:

[0027] S6.1. Input the node displacement data at the measuring points of the steam turbine pipeline collected in step S3 into the spatial beam element finite element model constructed in step S2. The input node information data is the spatial coordinates of the nodes of the spatial beam element, and the unit information data is the node numbers of the element, to obtain the spatial beam element;

[0028] S6.2. Set parameters for the spatial beam element obtained in step S6.1, and input the cross-sectional area A of the spatial beam element, the polar moment of inertia I about the cross-sectional center of the spatial beam element xx , the centroidal moment of inertia I of the cross-section of the spatial beam element about the y-axis yy , the centroidal moment of inertia I of the cross-section of the spatial beam element about the z-axis zz , the elastic modulus E of the cylinder material of the steam turbine, the tangential elastic modulus G of the cylinder material of the steam turbine, the outer diameter D of the spatial beam element, and the inner diameter d of the spatial beam element, to obtain the spatial beam element with parameters set. The calculation formulas between the parameters are as follows:

[0029] A = π(D 2 - d 2 ) / 4

[0030] I xx = π(D 4 - d 4 ) / 32

[0031] I yy = I zz = π(D 4 - d 4 ) / 64.

[0032] Furthermore, the specific implementation method of step S7 includes the following steps:

[0033] S7.1. Considering the influence of the thermal expansion of the cylinder metal material on the node displacement correction of the spatial beam element, correct the node displacement of the spatial beam element. The correction formula is:

[0034] X new = X old × (1 + α1) × (T 蒸汽 - 20)

[0035] Y new = Y old × (1 + α1) × (T 蒸汽 - 20)

[0036] Z new = Z old × (1 + α1) × (T 蒸汽 - 20)

[0037] Where X old , Y old, Z old are the coordinates of the node of the space beam element before correction, X new , Y new , Z new are the coordinates of the node of the space beam element after correction, T 蒸汽 is the steam temperature in the steam turbine pipeline, and α1 is the linear expansion coefficient of the steam turbine pipeline material at T 蒸汽 temperature;

[0038] S7.2. The constraint conditions of the space beam element include the node constraints at the interfaces of the steam turbine pipeline, the node displacement constraints of the steam turbine pipeline, and the node constraints at the supports and hangers of the steam turbine pipeline;

[0039] S7.2.1. Node constraints at the interfaces of the steam turbine pipeline: The displacement constraints in the X, Y, and Z directions applied to the nodes at the interfaces of the steam turbine pipeline are X 接口 , Y 接口 , Z 接口 ;

[0040] S7.2.2. Node displacement constraints of the steam turbine pipeline: The displacement constraints in the X, Y, and Z directions applied to the node displacements of the steam turbine pipeline are X 测量 -(X new -X old ), Y 测量 -(Y new -Y old ), Z 测量 -(Z new -Z old ), where X 测量 , Y 测量 , Z 测量 are the displacement values in the three directions measured at the nodes of the steam turbine pipeline;

[0041] S7.2.3. Node constraints at the supports and hangers of the steam turbine pipeline: A spring force F = KΔs is applied to the nodes at the supports and hangers of the steam turbine pipeline, where F is the spring force, K is the spring stiffness, and Δs is the displacement change at the supports and hangers of the steam turbine pipeline. The direction of the spring force is decomposed according to the installation direction and applied to the finite element model of the space beam element.

[0042] Furthermore, the node displacements in step S8 include U x , U y , U z , Phx, Phy, Phz, where U x , U y , U z are the node displacements in the x, y, and z directions respectively, and Phx, Phy, Phz are the node rotations in the x, y, and z directions respectively;

[0043] The element forces include N and T y and T z and M x and M y and M z , where N is the axial force of the element, and T y and T z are the element shear stresses in the y - direction and z - direction perpendicular to the axis, and M x is the axial torque of the element, and M y and M z are the element bending moments in the y - direction and z - direction;

[0044] The on - line stress calculation formula for the steam turbine pipeline in step S9 is:

[0045]

[0046] where: σ1 is the maximum normal stress at the node section of the steam turbine pipeline, P is the steam pressure, and I is the centroidal moment of inertia;

[0047] I = I yy = I zz .

[0048] An electronic device, including a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the steps of the on - line stress calculation method for a steam turbine pipeline are implemented.

[0049] A computer - readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the on - line stress calculation method for a steam turbine pipeline is implemented.

[0050] Advantages of the present invention:

[0051] The on - line stress calculation method for a steam turbine pipeline according to the present invention can automatically read the key nodes of the pipeline, generate a spatial beam element finite - element model of the pipeline, and at the same time mark the interface positions and the positions of the supports and hangers. Taking the displacement of the steam turbine cylinder of the on - site steam turbine unit and the displacement of the pipeline displacement measuring points as input and applying them to the finite - element model, the stress state of the pipeline can be calculated in real time. This method uses spatial beam elements for calculation, has low requirements for computer computing power, can be configured into the power plant in real time, and achieves the purpose of real - time monitoring of the pipeline stress state. Brief Description of the Drawings

[0052] Figure 1 is a flow chart of the on - line stress calculation method for a steam turbine pipeline according to the present invention. Detailed Embodiments

[0053] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the specific embodiments described are only a part of the embodiments of the present invention, rather than all of the specific embodiments. The components of the specific embodiments of the present invention usually described and shown in the accompanying drawings herein can be arranged and designed in various different configurations, and the present invention can also have other embodiments.

[0054] Therefore, the following detailed description of the specific embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents the selected specific embodiments of the present invention. Based on the specific embodiments of the present invention, all other specific embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

[0055] In order to further understand the content, features and effects of the present invention, the following specific embodiments are exemplified and described in detail in conjunction with the accompanying drawings as follows: Specific Embodiment 1:

[0057] An on-line stress calculation method for a steam turbine pipeline, comprising the following steps:

[0058] S1. Extract steam turbine pipeline data according to the CAD drawings of the steam turbine pipeline, including steam turbine pipeline spatial position data, steam turbine pipeline node data, steam turbine pipeline corner radius data, and steam turbine pipeline interface position data;

[0059] Further, the specific implementation method of step S1 is that the spatial position of the steam turbine pipeline is set as the origin from the starting interface of the steam turbine pipeline, and the spatial coordinate data of the corner bending points of the steam turbine pipeline, the steam turbine pipeline corner radius data, the inner diameter data and the outer diameter data of the steam turbine pipeline, and the position coordinate data of the steam turbine pipeline are sequentially extracted one by one until the end of the steam turbine pipeline;

[0060] S2. Use the steam turbine pipeline data obtained in step S1 to construct a spatial beam element finite element model of the steam turbine pipeline, and set the node information data format and element information data format of the spatial beam element finite element model;

[0061] Further, the specific implementation method of step S2 includes the following steps:

[0062] S2.1. Use the python package of Abaqus to generate elements and meshes for finite element calculation, read the position coordinate data of the steam turbine pipeline to generate point coordinates, connect the point coordinates into lines in sequence, and generate the steam turbine pipeline curve according to the steam turbine pipeline corner radius data;

[0063] S2.2. Mesh the steam turbine pipeline curve generated in step S2.1, and set the meshing parameters as size, deviationFactor, and minSizeFactor, where size represents the size with a value range of 0.04 - 0.06, deviationFactor represents the size deviation coefficient with a value range of 0.05 - 0.2, and minSizeFactor represents the minimum size coefficient with a value range of 0.05 - 0.2;

[0064] S2.3. Output the mesh divided in step S2.2 and select the spatial beam element. The data format of the output node information is: node number, node X coordinate, node Y coordinate, node Z coordinate. The data format of the output element information is element number, front node number, rear node number. At the same time, mark the nodes at the interfaces of the generated spatial beam elements, the nodes at the supports and hangers, and the nodes at the measuring points;

[0065] S3. Collect the on-site operation data of the steam turbine, including the node displacement data at the measuring points of the steam turbine pipeline and the operation data of the steam turbine. The operation data of the steam turbine includes the cylinder end displacement measurement data of the steam turbine, the cylinder temperature measurement data of the steam turbine, the steam inlet temperature data of the steam turbine pipeline, and the steam inlet pressure data of the steam turbine pipeline, for later use;

[0066] S4. Collect the cylinder material data of the steam turbine, and then calculate the elastic modulus and linear expansion coefficient of the cylinder material of the steam turbine at different temperatures, for later use;

[0067] Further, the specific implementation method of step S4 is that the collected cylinder material data of the steam turbine is the elastic modulus and linear expansion coefficient of the cylinder material of the steam turbine at 100°, 200°, 300°, 400°, 500°, and 600° temperatures. Then, use the linear extrapolation interpolation method to calculate the elastic modulus E and linear expansion coefficient of the cylinder material of the steam turbine at different temperatures;

[0068] S5. Calculate the cylinder interface displacement data of the steam turbine according to the operation data of the steam turbine collected in step S3 and the cylinder material data of the steam turbine obtained in step S4;

[0069] Further, the calculation formula for the cylinder interface displacement data of the steam turbine in step S5 is:

[0070] X 接口 =X 汽缸端部位移 -(T 汽缸 -20)×(1 + α)×x s

[0071] Y 接口 =(T 汽缸-20)×(1 + α)×y s

[0072] Z 接口 =(T 汽缸 -20)×(1 + α)×z s

[0073] where X 接口 、Y 接口 、Z 接口 are the displacements in the X, Y, and Z directions of the cylinder interface of the steam turbine, X 汽缸端部位移 is the displacement in the X direction at the cylinder end in the data of the steam turbine safety monitoring system, T 汽缸 is the temperature of the cylinder metal material in the data of the steam turbine safety monitoring system, α is the linear expansion coefficient of the cylinder metal material at temperature T 汽缸 x s is the distance in the X direction from the cylinder interface of the steam turbine to the cylinder end, y s is the distance in the Y direction from the cylinder interface of the steam turbine to the turbine foundation surface, z s is the distance in the Z direction from the cylinder interface of the steam turbine to the center line of the turbine rotor axis;

[0074] S6. Input the node displacement data at the measuring points of the steam turbine pipeline collected in step S3 into the spatial beam element finite element model constructed in step S2, input the node information data and element information data, and obtain the spatial beam element for parameter setting;

[0075] Furthermore, the specific implementation method of step S6 includes the following steps:

[0076] S6.1. Input the node displacement data at the measuring points of the steam turbine pipeline collected in step S3 into the spatial beam element finite element model constructed in step S2. The input node information data is the spatial coordinates of the nodes of the spatial beam element, and the element information data is the node numbers of the elements, to obtain the spatial beam element;

[0077] S6.2. Perform parameter setting on the spatial beam element obtained in step S6.1. Input the cross-sectional area A of the spatial beam element, the polar moment of inertia I with respect to the center of the cross-section of the spatial beam element xx , the central moment of inertia I of the cross-section y-axis of the spatial beam element yy , the central moment of inertia I of the cross-section z-axis of the spatial beam element zz , the elastic modulus E of the cylinder material of the steam turbine, the tangential elastic modulus G of the cylinder material of the steam turbine, the outer diameter D of the spatial beam element, and the inner diameter d of the spatial beam element, to obtain the spatial beam element with parameter setting completed. The calculation formula between the parameters is:

[0078] A = π(D 2 -d2 ) / 4

[0079] I xx =π(D 4 -d 4 ) / 32

[0080] I yy =I zz =π(D 4 -d 4 ) / 64;

[0081] The tangential elastic modulus G of the cylinder material of the steam turbine is a constant;

[0082] S7. Modify the nodal displacements of the space beam elements obtained in step S6 and add the constraint conditions of the space beam elements;

[0083] Furthermore, the specific implementation method of step S7 includes the following steps:

[0084] S7.1. When modifying the nodal displacements of the space beam elements, consider the influence of the thermal expansion of the cylinder metal material and modify the nodal displacements of the space beam elements. The modification formula is:

[0085] X new =X old ×(1 + α1) × (T 蒸汽 -20)

[0086] Y new =Y old ×(1 + α1) × (T 蒸汽 -20)

[0087] Z new =Z old ×(1 + α1) × (T 蒸汽 -20)

[0088] Where X old 、Y old 、Z old are the coordinates of the nodes of the space beam element before modification, X new 、Y new 、Z new are the coordinates of the nodes of the space beam element after modification, T 蒸汽 is the steam temperature in the steam turbine pipeline, and α1 is the linear expansion coefficient of the steam turbine pipeline material at the temperature of T 蒸汽 ;

[0089] S7.2. The constraint conditions of the space beam element include the node constraints at the interfaces of the steam turbine pipelines, the node displacement constraints of the steam turbine pipelines, and the node constraints at the supports and hangers of the steam turbine pipelines;

[0090] S7.2.1, Node Constraints at the Interface of Steam Turbine Pipelines: The displacement constraints in the X, Y, and Z directions applied to the nodes at the interface of steam turbine pipelines are X 接口 , Y 接口 , Z 接口 ;

[0091] S7.2.2, Node Displacement Constraints of Steam Turbine Pipelines: The displacement constraints in the X, Y, and Z directions applied to the node displacements of steam turbine pipelines are X 测量 -(X new -X old ), Y 测量 -(Y new -Y old ), Z 测量 -(Z new -Z old ), where X 测量 , Y 测量 , Z 测量 are the displacement values in the three directions measured at the nodes of the steam turbine pipeline;

[0092] S7.2.3, Node Constraints at the Supports and Hangers of Steam Turbine Pipelines: A spring force F = KΔs is applied to the nodes at the supports and hangers of steam turbine pipelines, where F is the spring force, K is the spring stiffness, and Δs is the displacement change at the supports and hangers of the steam turbine pipeline. The direction of the spring force is decomposed according to the installation direction and applied to the finite element model of the space beam element;

[0093] S8. Use the feon library to construct the mass matrix and stiffness matrix of the space beam element obtained in step S6, establish a solver to solve the finite element model of the space beam element, obtain the node displacements of the steam turbine pipeline and the node element forces of the steam turbine pipeline, and then calculate the maximum normal stress at the nodes of the steam turbine pipeline;

[0094] Furthermore, the node displacements in step S8 include U x , U y , U z , Phx, Phy, Phz, where U x , U y , U z are the node displacements in the x, y, and z directions respectively, and Phx, Phy, Phz are the node rotations in the x, y, and z directions respectively;

[0095] The element forces include N, T y , T z , M x , M y , M z , where N is the axial force of the element, T y , T zare the unit shear stresses in the y and z directions perpendicular to the axis, M x is the unit axial torque, M y 、M z are the unit bending moments in the y and z directions;

[0096] The on-line stress calculation formula for the steam turbine pipeline in step S9 is:

[0097]

[0098] Where: σ1 is the maximum normal stress at the node section of the steam turbine pipeline, P is the steam pressure, and I is the central moment of inertia;

[0099] I = I yy = I zz .

[0100] S9. Repeat steps S3 - S8 to calculate the on-line stress of the steam turbine pipeline. Specific Embodiment 2:

[0102] An electronic device, including a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the steps of the on-line stress calculation method for a steam turbine pipeline are implemented.

[0103] The computer device of the present invention may be a device including a processor and a memory, such as a single-chip microcomputer including a central processing unit. And, when the processor is used to execute the computer program stored in the memory, the steps of the above-mentioned recommendation method for modifiable relationship-driven recommendation data based on CREO software are implemented.

[0104] The so-called processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0105] The memory may mainly include a program storage area and a data storage area. Among them, the program storage area may store an operating system, application programs required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area may store data created according to the use of the mobile phone (such as audio data, phone book, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as a hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one magnetic disk storage device, flash memory device, or other volatile solid-state storage devices. Specific Embodiment 3:

[0107] A computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the on-line stress calculation method for a steam turbine pipeline described above is implemented.

[0108] The computer-readable storage medium of the present invention can be any form of storage medium readable by the processor of the computer device, including but not limited to non-volatile memory, volatile memory, ferroelectric memory, etc. A computer program is stored on the computer-readable storage medium. When the processor of the computer device reads and executes the computer program stored in the memory, the steps of the above-mentioned modeling method for modifiable relationship-driven modeling data based on CREO software can be implemented. The computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0109] It should be noted that relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0110] Although the present application has been described above with reference to specific embodiments, various improvements can be made thereto and components thereof can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the various features in the specific embodiments disclosed in the present application can be combined with each other in any way, and the exhaustive description of the combinations is not given in this specification only for the sake of saving space and resources. Therefore, the present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An on-line stress calculation method for steam turbine pipelines, characterized in that: It includes the following steps: S1. Extract the steam turbine pipeline data according to the CAD drawing of the steam turbine pipeline, including the spatial position data of the steam turbine pipeline, the node data of the steam turbine pipeline, the corner radius data of the steam turbine pipeline, and the interface position data of the steam turbine pipeline; S2. Utilize the steam turbine pipeline data obtained in step S1 to construct a spatial beam element finite element model of the steam turbine pipeline, and set the node information data format and element information data format of the spatial beam element finite element model; S3. Collect the on-site operation data of the steam turbine, including the node displacement data at the measuring points of the steam turbine pipeline and the operation data of the steam turbine. The operation data of the steam turbine includes the cylinder end displacement measurement data of the steam turbine, the cylinder temperature measurement data of the steam turbine, the steam inlet temperature data of the steam turbine pipeline, and the steam inlet pressure data of the steam turbine pipeline, for later use; S4. Collect the cylinder material data of the steam turbine, and then calculate the elastic modulus and linear expansion coefficient of the cylinder material of the steam turbine at different temperatures, for later use; S5. Calculate the cylinder interface displacement data of the steam turbine according to the operation data of the steam turbine collected in step S3 and the cylinder material data of the steam turbine obtained in step S4; S6. Input the node displacement data at the measuring points of the steam turbine pipeline collected in step S3 into the spatial beam element finite element model constructed in step S2, input the node information data and element information data, and obtain the parameter settings of the spatial beam element; S7. Correct the node displacement of the spatial beam element obtained in step S6, and add the constraint conditions of the spatial beam element; S8. Use the feon library to construct the mass matrix and stiffness matrix of the spatial beam element obtained in step S6, establish a solver to solve the spatial beam element finite element model, obtain the node displacement of the steam turbine pipeline and the node element force of the steam turbine pipeline, and then calculate the maximum normal stress of the nodes of the steam turbine pipeline; S9. Repeat steps S3 - S8 to calculate the online stress of the steam turbine pipeline.

2. The on-line stress calculation method for a steam turbine pipeline according to claim 1, characterized in that: The specific implementation method of step S1 is to set the spatial position of the steam turbine pipeline with the starting interface of the steam turbine pipeline as the origin, and sequentially extract the spatial coordinate data of the corner bending points of the steam turbine pipeline, the corner radius data of the steam turbine pipeline, the inner diameter data and outer diameter data of the steam turbine pipeline, and the position coordinate data of the steam turbine pipeline until the end of the steam turbine pipeline.

3. A method for on-line stress calculation of a steam turbine pipeline according to claim 2, characterized in that: The specific implementation method of step S2 includes the following steps: S2.

1. Use the python package of Abaqus to generate the elements and meshes for finite element calculation, read the position coordinate data of the steam turbine pipeline to generate point coordinates, connect the point coordinates into lines in sequence, and generate the steam turbine pipeline curve according to the corner radius data of the steam turbine pipeline; S2.

2. Mesh the steam turbine pipeline curve generated in step S2.1, and set the meshing parameters as size, deviationFactor, and minSizeFactor. Here, size represents the size, with a value range of 0.04 - 0.06; deviationFactor represents the size deviation coefficient, with a value range of 0.05 - 0.2; minSizeFactor represents the minimum size coefficient, with a value range of 0.05 - 0.

2. S2.

3. Output the mesh divided in step S2.2 and select the spatial beam element. The data format of the output node information is: node number, node X coordinate, node Y coordinate, node Z coordinate. The data format of the output element information is element number, previous node number, and next node number. At the same time, mark the nodes at the interfaces of the generated spatial beam elements, the nodes at the supports and hangers, and the nodes at the measuring points.

4. A method for on-line stress calculation of a steam turbine pipeline according to claim 3, characterized in that: The specific implementation method of step S4 is to collect the elastic modulus and linear expansion coefficient of the steam turbine cylinder material at temperatures of 100°, 200°, 300°, 400°, 500°, and 600° for the steam turbine cylinder material, and then use the linear extrapolation interpolation method to calculate the elastic modulus E and linear expansion coefficient of the steam turbine cylinder material at different temperatures.

5. A method for online stress calculation of a steam turbine pipeline according to claim 4, characterized in that: In step S5, the calculation formula for the displacement data of the steam turbine cylinder interface is: X 接口 = X 汽缸端部位移 -(T 汽缸 - 20) × (1 + α) × x s Y 接口 = (T 汽缸 - 20) × (1 + α) × y s Z 接口 = (T 汽缸 - 20) × (1 + α) × z s Among them, X 接口 , Y 接口 , Z 接口 are the displacements in the X, Y, and Z directions of the cylinder interface of the steam turbine. X 汽缸端部位移 is the displacement in the X direction at the end of the cylinder in the data of the steam turbine safety monitoring system. T 汽缸 is the temperature of the cylinder metal material in the data of the steam turbine safety monitoring system. α is the linear expansion coefficient of the cylinder metal material at temperature T 汽缸 . x s is the distance in the X direction from the cylinder interface of the steam turbine to the end of the cylinder. y s is the distance in the Y direction from the cylinder interface of the steam turbine to the base surface of the steam turbine. z s is the distance in the Z direction from the cylinder interface of the steam turbine to the center line of the axis of the steam turbine rotor.

6. The on-line stress calculation method for a steam turbine pipeline according to claim 5, characterized in that: The specific implementation method of step S6 includes the following steps: S6.

1. Input the node displacement data at the measuring points of the steam turbine pipeline collected in step S3 into the spatial beam element finite element model constructed in step S2. The input node information data is the spatial coordinates of the nodes of the spatial beam element, and the input element information data is the node numbers of the elements, to obtain the spatial beam element. S6.

2. Set parameters for the spatial beam element obtained in step S6.1, and input the cross-sectional area A of the spatial beam element, the polar moment of inertia I with respect to the center of the cross-section of the spatial beam element xx , the centroidal moment of inertia I of the cross-section of the spatial beam element about the y-axis yy , the centroidal moment of inertia I of the cross-section of the spatial beam element about the z-axis zz , the elastic modulus E of the cylinder material of the steam turbine, the tangential elastic modulus G of the cylinder material of the steam turbine, the outer diameter D of the spatial beam element, and the inner diameter d of the spatial beam element, to obtain the spatial beam element with parameters set. The calculation formulas between the parameters are as follows: A = π(D 2 - d 2 ) / 4 I xx = π(D 4 - d 4 ) / 32 I yy = I zz = π(D 4 - d 4 ) / 64。 7. A method for online stress calculation of a steam turbine pipeline according to claim 6, characterized in that: The specific implementation method of step S7 includes the following steps: S7.

1. Consider the influence of the thermal expansion of the cylinder metal material on the node displacement correction of the spatial beam element, and correct the node displacement of the spatial beam element. The correction formula is: X new = X old ×(1 + α1)×(T 蒸汽 - 20) Y new = Y old ×(1 + α1)×(T 蒸汽 - 20) Z new = Z old × (1 + α1) × (T 蒸汽 - 20) Where X old , Y old , Z old are the coordinates of the nodes of the space beam element before correction, X new , Y new , Z new are the coordinates of the nodes of the space beam element after correction, T 蒸汽 is the steam temperature in the steam turbine pipeline, and α1 is the linear expansion coefficient of the steam turbine pipeline material at the temperature of T 蒸汽 ; S7.

2. The constraint conditions of the spatial beam element include the node constraints at the interfaces of the steam turbine pipeline, the node displacement constraints of the steam turbine pipeline, and the node constraints at the supports and hangers of the steam turbine pipeline. S7.2.

1. Node constraints at the interfaces of steam turbine pipelines: The displacement constraints in the X, Y, and Z directions applied to the nodes at the interfaces of steam turbine pipelines are X 接口 , Y 接口 , Z 接口 ; S7.2.2, Node Displacement Constraints of Steam Turbine Pipelines: The displacement constraints in the X, Y, and Z directions applied to the node displacements of steam turbine pipelines are X 测量 -(X new -X old )、Y 测量 -(Y new -Y old )、Z 测量 -(Z new -Z old ), where X 测量 、Y 测量 、Z 测量 are the displacement values in three directions measured at the nodes of the steam turbine pipeline; S7.2.

3. Node constraints at the supports and hangers of the steam turbine pipeline: Apply a spring force F = KΔs to the nodes at the supports and hangers of the steam turbine pipeline, where F is the spring force, K is the spring stiffness, and Δs is the displacement change at the supports and hangers of the steam turbine pipeline. The direction of the spring force is decomposed according to the installation direction and applied to the spatial beam element finite element model.

8. A method for on-line stress calculation of a steam turbine pipeline according to claim 7, characterized in that: The nodal displacements in step S8 include U x , U y , U z , Phx, Phy, Phz, where U x , U y , U z are the nodal displacements in the x, y, and z directions respectively, and Phx, Phy, Phz are the nodal rotations in the x, y, and z directions respectively; The element forces include N and T y and T z and M x and M y and M z , where N is the axial force of the element, and T y and T z are the element shear stresses in the y and z directions perpendicular to the axis, and M x is the axial torque of the element, and M y and M z are the element bending moments in the y and z directions; In step S9, the online stress calculation formula for the steam turbine pipeline is: Where: σ1 is the maximum normal stress at the node section of the steam turbine pipeline, P is the steam pressure, and I is the central moment of inertia; I = I yy = I zz 。 9. An electronic device, characterized in that, It includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the steps of a method for calculating the online stress of a steam turbine pipeline according to any one of claims 1 - 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements a method for calculating the online stress of a steam turbine pipeline according to any one of claims 1 - 7.

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