CN-122021119-A - Turbine unit shafting fault early warning method and device, storage medium and electronic equipment

CN122021119ACN 122021119 ACN122021119 ACN 122021119ACN-122021119-A

Abstract

The application discloses a turbine unit shafting fault early warning method, a device, a storage medium and electronic equipment. The method comprises the steps of establishing a fan-shaped crack shafting solid model based on solid structure parameters of a target turbine unit shafting, defining nonlinear crack force by adopting a penalty function aiming at finite element nodes in the fan-shaped crack shafting solid model, collecting rigidity characteristic parameters of a bearing, constructing a large-freedom dynamic equation of the fan-shaped crack shafting according to the nonlinear crack force and the rigidity characteristic parameters, solving the large-freedom dynamic equation in an iterative mode to obtain shafting steady-state response, determining shafting vibration amplitudes respectively corresponding to different fan-shaped crack characteristic parameters based on the shafting steady-state response, and outputting crack fault early warning signals if the shafting vibration amplitudes exceed a preset vibration safety threshold.

Inventors

SONG TONGTONG
SONG YAJUN
ZHANG WEI
DONG WEI
SI PAIYOU
MEI LONG
LIU SHUANGBAI
HAO XIANGZHONG

Assignees

华北电力科学研究院有限责任公司
国家电网有限公司

Dates

Publication Date: 20260512
Application Date: 20251226

Claims (10)

1. The shafting fault early warning method for the steam turbine unit is characterized by comprising the following steps of: establishing a fan-shaped crack shafting solid model based on solid structure parameters of a target turbine set shafting; defining nonlinear crack force by adopting a penalty function aiming at finite element nodes in the fan-shaped crack shafting entity model; acquiring rigidity characteristic parameters of a bearing in the target turbine unit shafting, and constructing a large-freedom dynamic equation of the target turbine unit shafting according to the nonlinear crack force and the rigidity characteristic parameters; Solving the large-freedom-degree dynamic equation in an iterative mode to obtain shafting steady-state response; determining shafting vibration amplitudes respectively corresponding to different sector crack characteristic parameters based on the shafting steady-state response; And if the shafting vibration amplitude exceeds a preset vibration safety threshold, outputting a fault early warning signal.
2. The method of claim 1, wherein establishing a fan crack shafting solid model based on solid structure parameters of a target turbine set shafting comprises: Determining the structure and the size of a shafting basic model according to the physical structure parameters of the target turbine unit shafting so as to construct the shafting basic model; determining a crack section according to a preset crack position of the shafting basic model, wherein the crack section comprises a crack surface and a continuous surface; according to the shape requirement of the sector-shaped crack, determining the dimensionless depth and the expansion angle of the crack, and constructing a sector-shaped crack geometric structure at the crack surface based on the dimensionless depth and the expansion angle; And fusing the fan-shaped crack geometric structure with the shafting basic model to form the fan-shaped crack shafting solid model.
3. The method of claim 2, wherein defining nonlinear crack forces with a penalty function for finite element nodes in the fan crack shafting solid model comprises: determining left-side entity nodes and right-side entity nodes to which the crack surfaces belong according to the distribution condition of the crack surfaces in the fan-shaped crack shafting entity model, and forming node pairs; According to Defining a nonlinear crack force of the finite element node, wherein, Is the crack force of the right-hand physical node, As the crack force of the left entity node, u l is the normal displacement of the left entity node, u r is the normal displacement of the right entity node, and K p is the penalty coefficient of the node pair.
4. A method according to claim 3, wherein collecting stiffness characteristic parameters of bearings in the target turbine set shafting, and constructing a large degree of freedom kinetic equation of the target turbine set shafting according to the nonlinear crack force and the stiffness characteristic parameters, comprises: In a rotating coordinate system, acquiring rigidity characteristic parameters of the bearing, wherein the rigidity characteristic parameters comprise a bearing static rigidity component Cosine modulation term of bearing rigidity Sinusoidal modulation term for bearing stiffness The fundamental angular frequency Ω of the excitation; substituting the nonlinear crack force into a basic equation of shafting dynamics, and determining a large-freedom-degree dynamic equation of the fan-shaped crack shafting as Wherein, the M r is a crack rotor mass matrix, u is a system displacement vector, As a system velocity vector, the velocity vector, As a vector of the acceleration of the system, For the damping matrix of the cracked rotor, As a static stiffness matrix for a cracked rotor, For a crack rotor rotational softening matrix, F ％ra (t) is the gravity vector and F crack (u) is the crack nonlinear force vector.
5. The method according to claim 4, wherein the method further comprises: Carrying out substructure division on the fan-shaped crack shafting, and determining a fixed interface of each substructure; Solving a main modal matrix, a bearing node displacement constraint modal matrix and a crack surface node displacement constraint modal matrix of each substructure based on a fixed interface of each substructure; Constructing a modal transformation matrix and a coordinate vector of a reduced rotor system according to the main modal matrix, the bearing node displacement constraint modal matrix and the crack surface node displacement constraint modal matrix; substituting the modal transformation matrix and the coordinate vector of the reduced rotor system into the large-freedom-degree dynamic equation, and obtaining a reduced fan-shaped crack rotor system dynamic equation through matrix operation.
6. The method of claim 5, wherein solving the large degree of freedom dynamics equation in an iterative manner results in an shafting steady state response, comprising: converting the dynamic equation of the sector crack rotor system after the shrinkage into a complex exponential form; respectively performing Fourier series expansion processing on the steady-state response, the linear exciting force and the nonlinear crack force of the rotor system; substituting the unfolded steady-state response, linear exciting force and nonlinear crack force into a dynamic equation in a complex exponential form, and establishing a solving equation according to the principle that the coefficients of the same exponential terms are equal; setting initial iteration parameters of an iteration method, substituting the initial iteration parameters into the solving equation to perform iterative calculation until a calculation result meets a preset convergence condition, and outputting shafting steady-state response.
7. The method of claim 6, wherein determining shafting vibration magnitudes for different sector crack characteristic parameters, respectively, based on the shafting steady state response comprises: extracting the amplitude information of the displacement vector from the shafting steady-state response; Respectively carrying out association matching on the non-dimensional depths and the expansion angles of different sector cracks and the amplitude information, and establishing a one-to-one correspondence; and determining the shafting vibration amplitude corresponding to each fan-shaped crack characteristic parameter combination according to the corresponding relation.
8. A turboset shafting fault early warning device, characterized in that the device comprises: the construction module is used for constructing a fan-shaped crack shafting solid model based on the solid structure parameters of the target turbine set shafting; the definition module is used for defining nonlinear crack force by adopting a penalty function aiming at the finite element nodes in the fan-shaped crack shafting solid model; the construction module is also used for collecting rigidity characteristic parameters of the bearing and constructing a large-freedom dynamic equation of the fan-shaped crack shafting according to the nonlinear crack force and the rigidity characteristic parameters; The solving module is used for solving the large-freedom-degree dynamic equation in an iterative mode to obtain shafting steady-state response; the determining module is used for determining shafting vibration amplitudes respectively corresponding to different sector crack characteristic parameters based on the shafting steady-state response; and the output module is used for outputting a fault early warning signal if the shafting vibration amplitude exceeds a preset vibration safety threshold.
9. A storage medium, characterized in that the storage medium comprises a stored program, wherein the device in which the storage medium is located is controlled to execute the turboset shafting fault early warning method according to any one of claims 1 to 7 when the program is run.
10. An electronic device, characterized in that the device comprises at least one processor, at least one memory and a bus connected with the processor, wherein the processor and the memory are in communication with each other through the bus, and the processor is used for calling program instructions in the memory to execute the turboset shafting fault early warning method according to any one of claims 1-7.

Description

Turbine unit shafting fault early warning method and device, storage medium and electronic equipment Technical Field The application relates to the technical field of power grids, in particular to a turbine unit shafting fault early warning method and device, a storage medium and electronic equipment. Background Under the background that energy structure transformation and thermal power generating unit flexibility operation demands are increasingly improved, a turbine unit shafting needs to frequently operate for a long time under the condition of deviating from a design working condition, so that fatigue cracks are extremely easy to occur on the surface of a rotor. As a core transmission component of the turbine unit, once a crack appears in a shafting, the expansion process of the shafting has strong nonlinearity and unpredictability. The traditional shafting fault detection technology relies on a simplified centralized quality model, a beam unit model or a transfer matrix model to carry out modeling analysis on the rotor. The simplified model is difficult to accurately represent geometric features and dynamic respiration effects of complex crack forms such as sector cracks, key dynamics factors such as rigidity time-varying characteristics of a bearing, rotor rotation softening effects and the like cannot be fully coupled, deviation between a simulation result and an actual running state of a shaft system is large, and fine vibration anomalies caused by early cracks are difficult to accurately capture. When cracks develop to a certain extent, the traditional method can only identify faults when vibration is obviously exceeded, at the moment, the shafting probably faces fracture risks, early warning cannot be achieved, and safe and stable operation of the turbine unit and power supply reliability of a power grid are seriously threatened. Disclosure of Invention In view of the above problems, the application provides a turbine unit shafting fault early warning method, a device, a storage medium and electronic equipment. In order to solve the technical problems, the application provides the following scheme: The application provides a turbine unit shafting fault early warning method, which comprises the steps of establishing a fan-shaped crack shafting solid model based on solid structure parameters of a target turbine unit shafting, defining nonlinear crack force by adopting a penalty function aiming at finite element nodes in the fan-shaped crack shafting solid model, collecting rigidity characteristic parameters of a bearing, constructing a large-freedom dynamics equation of the fan-shaped crack shafting according to the nonlinear crack force and the rigidity characteristic parameters, solving the large-freedom dynamics equation in an iterative mode to obtain shafting steady-state response, determining shafting vibration amplitudes corresponding to different fan-shaped crack characteristic parameters respectively based on the shafting steady-state response, and outputting crack fault early warning signals if the shafting vibration amplitudes exceed a preset vibration safety threshold. In a second aspect, the present application provides a turboset shafting fault early-warning device, where the turboset shafting fault early-warning device includes: the construction module is used for constructing a fan-shaped crack shafting solid model based on the solid structure parameters of the target turbine set shafting; The definition module is used for defining nonlinear crack force by adopting a penalty function aiming at finite element nodes in the fan-shaped crack shafting solid model; the construction module is also used for collecting the rigidity characteristic parameters of the bearing and constructing a large-freedom dynamic equation of the fan-shaped crack shafting according to the nonlinear crack force and the rigidity characteristic parameters; The solving module is used for solving the dynamics equation with large freedom degree in an iterative mode to obtain shafting steady-state response; The determining module is used for determining shafting vibration amplitudes respectively corresponding to different sector crack characteristic parameters based on shafting steady-state response; And the output module is used for outputting a fault early warning signal if the vibration amplitude of the shafting exceeds a preset vibration safety threshold value. In order to achieve the above object, according to a third aspect of the present application, there is provided a storage medium including a stored program, wherein the apparatus in which the storage medium is controlled to execute the turboset shafting fault early warning method of the first aspect when the program runs. In order to achieve the above object, according to a fourth aspect of the present application, there is provided an electronic device, the device including at least one processor, and at least one memory and a bus connected to the processor