Method and device for calculating dynamic stress of upper bracket of semi-umbrella type hydro-generator

Abstract

The application provides a semi-umbrella type water turbine generator upper bracket dynamic stress calculation method and device, and the method comprises the following steps: obtaining first vibration waveforms of a first direction and a second direction of a semi-umbrella type water turbine generator upper bracket, wherein the first direction and the second direction are horizontal extension directions of the semi-umbrella type water turbine generator upper bracket and are perpendicular to each other; calculating bearing load angles and bearing loads of each first time point according to the first vibration waveforms of the first direction and the second direction and preset standard load data to form bearing load data; and performing transient analysis on at least one target node in a preset load time period according to the bearing load data to obtain dynamic stresses of the target node at each second time point in the preset load time period. The application can improve the accuracy of upper bracket stress calculation and help maintain the operation stability of the unit.

Description

Technical Field

[0001] This invention belongs to the field of hydro-generator technology, specifically relating to a method and device for calculating the dynamic stress of the upper frame of a semi-umbrella hydro-generator. Background Technology

[0002] Hydropower, as a clean energy source, has been extensively developed. During operation, hydro-turbine generator units generate mechanical vibrations. Excessive vibration can cause fasteners to loosen, components to crack, or even break, thus affecting the normal operation of the unit and reducing the utilization of hydropower resources. With the large-scale construction of hydro-turbine generator units, the operational stability of these units has become increasingly important. In hydro-turbine generator units, excitation forces are commonly categorized into hydraulic excitation forces, mechanical excitation forces, and electromagnetic excitation forces. These excitation forces induce various vibrations, making vibration problems highly complex. The upper frame of the hydro-turbine generator, as a crucial component of the unit, is critical to the safe operation of the entire unit.

[0003] Hydro-generator units experience three types of loads during operation: hydraulic excitation force, mechanical excitation force, and electromagnetic force. The magnitude of each load is closely related to the unit's design and manufacturing level, operating conditions, and installation quality. These three loads also influence and couple with each other. The upper frame of a semi-umbrella type hydro-generator is a non-load-bearing frame, bearing the radial force transmitted from the rotating parts of the generator through the upper guide bearing. Currently, the method for calculating the radial load on the upper frame relies on empirical estimations of rotor mass imbalance, stator-rotor air gap non-uniformity coefficient, and hydraulic imbalance force. Then, the stiffness of the upper guide support, lower guide support, and water guide support are calculated, finally determining the radial load on the upper frame and subsequently the static stress. However, this calculation result has a significant error compared to the actual stress level of the upper frame. Therefore, it is necessary to perform accurate calculations of the upper frame stress, especially the dynamic stress under various operating conditions. Summary of the Invention

[0004] This invention provides a method and apparatus for calculating the dynamic stress of the upper frame of a semi-umbrella-type hydro-generator, in order to solve the problems of inaccurate calculation of the dynamic stress of the upper frame and low operational stability of the hydro-generator unit.

[0005] Based on the above objectives, embodiments of the present invention provide a method for calculating the dynamic stress of the upper frame of a semi-umbrella hydro-generator, comprising: acquiring first vibration waveforms of the upper frame of the semi-umbrella hydro-generator in a first direction and a second direction, wherein the first direction and the second direction are the horizontal extension directions of the upper frame of the semi-umbrella hydro-generator and are perpendicular to each other; calculating the bearing load angle and bearing load at each first time point based on the first vibration waveforms in the first direction and the second direction and preset standard load data to form bearing load data; and performing transient analysis on at least one target node within a preset load time period based on the bearing load data to obtain the dynamic stress of the target node at each second time point within the preset load time period.

[0006] Optionally, before acquiring the vibration waveforms of the upper frame of the semi-umbrella-type hydro-generator in the first and second directions, the process includes: constructing a model of the upper frame of the hydro-generator using modeling software, wherein the upper frame is meshed using SOLID187 elements, and surface effect elements SURF154 are divided on the cylindrical surface inside the bearing housing ring; based on the upper frame model of the hydro-generator, a preset number of load data in the first and second directions are acquired under a preset standard load to obtain the standard load data.

[0007] Optionally, the step of obtaining a preset number of load data points in the first and second directions based on the upper frame model of the hydro-generator under a preset standard load, to obtain standard load data, includes: measuring the second vibration waveforms of the upper frame model of the hydro-generator in the first and second directions respectively when the bearing load is the preset standard load; extracting the deformation values ​​of the preset number of standard bearing load angles in the first and second directions of the upper frame model of the hydro-generator at preset angle intervals, and the ratio of the first deformation value in the first direction to the second direction, respectively, based on the second vibration waveforms; storing the preset number of standard bearing load angles, the deformation values ​​in the first and second directions corresponding to each standard bearing load angle, and the ratio of the first deformation value, to form the standard load data.

[0008] Optionally, the standard load data includes: a preset number of standard bearing load angles, deformation values ​​in a first direction and a second direction corresponding to each standard bearing load angle, and a ratio of the first deformation values ​​in the first direction and the second direction; the step of calculating the bearing load angle and bearing load at each first time point based on the first vibration waveform in the first direction and the preset standard load data to form bearing load data includes: extracting the deformation values ​​in the first direction and the second direction at each first time point based on the first vibration waveform in the first direction and the second direction, and calculating the ratio of the second deformation values ​​between the two; and calculating the ratio of the second deformation values ​​in the first direction and the second direction, and the ratio of the first deformation values ​​corresponding to each standard bearing load angle in the standard load data. The bearing load angle at each first time point is calculated using an interpolation method. Based on the bearing load angle and the deformation value in the first direction corresponding to each standard bearing load angle in the standard load data, the deformation calculation value in the first direction corresponding to the bearing load angle is calculated using an interpolation method. The standard bearing load angle and the deformation value in the first direction corresponding to the standard bearing load angle are found in the standard load data. The bearing load is calculated based on the deformation calculation value in the first direction, the standard bearing load angle, and the corresponding deformation value in the first direction. The bearing load data for the upper frame of the semi-umbrella-type hydro-generator is formed by combining the bearing load angle and bearing load at each first time point.

[0009] Optionally, the step of performing transient analysis on at least one target node within a preset load time period based on the bearing load data to obtain the dynamic stress of the target node at each second time point within the preset load time period includes: determining each second time point within the preset load time period with a preset time step; for any second time point, calculating the bearing load and bearing load angle at the second time point using interpolation based on the bearing load data; selecting all nodes on the cylindrical surface inside the bearing race of the upper frame model of the hydro-generator, and applying the bearing load to the bearing race based on the surface effect elements of all nodes; calculating the dynamic stress of all mesh points of the upper frame model of the hydro-generator, and extracting the dynamic stress of the target node.

[0010] Optionally, before performing transient analysis on at least one target node within a preset load time period based on the bearing load data, the method further includes: reading the bearing load data and splitting the bearing load data into a first data table storing time and bearing load and a second data table storing time and bearing load angle; the method of calculating the bearing load and bearing load angle at the second time point using interpolation based on the bearing load data includes: calculating the bearing load at the second time point using interpolation based on the first data table; and calculating the bearing load angle at the second time point using interpolation based on the second data table.

[0011] Optionally, selecting all nodes on the cylindrical surface inside the bearing race of the turbine generator upper frame model includes: establishing a local Cartesian coordinate system, rotating the Z-axis of the local Cartesian coordinate system relative to the Z-axis of the global Cartesian coordinate system by the bearing load angle; and selecting all nodes in the newly established local Cartesian coordinate system whose first direction coordinates inside the bearing race are between 0 and 2 / 2 of the bearing diameter.

[0012] Based on the same inventive concept, this invention also provides a dynamic stress calculation device for the upper frame of a semi-umbrella hydro-generator, comprising: a waveform acquisition module for acquiring first vibration waveforms of the upper frame of the semi-umbrella hydro-generator in a first direction and a second direction, wherein the first direction and the second direction are the horizontal extension directions of the upper frame of the semi-umbrella hydro-generator and are perpendicular to each other; a load data acquisition module for calculating the bearing load angle and bearing load at each first time point based on the first vibration waveforms in the first direction and the second direction and preset standard load data, thereby forming bearing load data; and a transient analysis module for performing transient analysis on at least one target node within a preset load time period based on the bearing load data, thereby acquiring the dynamic stress of the target node at each second time point within the preset load time period.

[0013] Based on the same inventive concept, embodiments of the present invention also provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the aforementioned method.

[0014] Based on the same inventive concept, embodiments of the present invention also provide a computer storage medium storing at least one executable instruction that causes a processor to execute the aforementioned method.

[0015] As can be seen from the above, the method and apparatus for calculating the dynamic stress of the upper frame of a semi-umbrella hydro-generator provided by the embodiments of the present invention obtains the first vibration waveforms of the upper frame of the semi-umbrella hydro-generator in a first direction and a second direction, wherein the first direction and the second direction are the horizontal extension directions of the upper frame of the semi-umbrella hydro-generator and are perpendicular to each other; calculates the bearing load angle and bearing load at each first time point based on the first vibration waveforms in the first direction and the second direction and preset standard load data to form bearing load data; and performs transient analysis on at least one target node within a preset load time period based on the bearing load data to obtain the dynamic stress of the target node at each second time point within the preset load time period. This can improve the accuracy of the upper frame stress calculation and help maintain the operational stability of the unit. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in one or more embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one or more embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a method for calculating the dynamic stress on the upper frame of a semi-umbrella-type hydro-generator according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the upper frame of the semi-umbrella-type hydro-generator in an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of a method for obtaining dynamic stress at each second time point through transient analysis in an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the dynamic stress calculation device for the upper frame of a semi-umbrella-type hydro-generator according to an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0023] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in the embodiments of this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0024] This invention also provides a method for calculating the dynamic stress on the upper frame of a semi-umbrella-type hydro-generator. (See attached...) Figure 1 As shown, the calculation method for dynamic stress on the upper frame of a semi-umbrella hydro-generator includes:

[0025] Step S11: Obtain the first vibration waveforms in the first X direction and the second Y direction of the upper frame of the semi-umbrella hydro-generator, wherein the first X direction and the second Y direction are the horizontal extension directions of the upper frame of the semi-umbrella hydro-generator and are perpendicular to each other.

[0026] In this embodiment of the invention, a model of the upper frame of the hydro-generator is constructed using modeling software. The upper frame is meshed using SOLID187 elements, and surface effect elements SURF154 are used on the cylindrical surface inside the bearing housing. A three-dimensional coordinate axis (X, Y, Z) is established for the upper frame to obtain vibration waveforms. The elastic modulus of the upper frame material is 2.068E+5MPa, and the Poisson's ratio is 0.3. The tangential degrees of freedom of the upper frame support legs and the contact surface with the foundation are constrained.

[0027] Based on the upper frame model of the hydro-generator, standard load data is obtained by acquiring a first direction (X-axis) and a second direction (Y-axis) under a preset standard load. Specifically, when the bearing load is the preset standard load, the second vibration waveforms of the upper frame model of the hydro-generator in the first and second directions are measured respectively. At preset angle intervals, the deformation values ​​of a preset number of standard bearing load angles in the first and second directions of the upper frame model of the hydro-generator are extracted according to the second vibration waveforms, along with the ratio of the first deformation value in the first direction to the first deformation value in the second direction. The preset number of standard bearing load angles, the deformation values ​​in the first and second directions corresponding to each standard bearing load angle, and the ratio of the first deformation value are stored to form the standard load data.

[0028] The standard load is a preset total bearing load of 1000N. The load direction is divided into 6° intervals, and the stiffness and strength analysis of the upper frame is calculated under 60 loads within a 360° range. The stiffness and strength of the upper frame is calculated sequentially as follows: the first load is calculated when the bearing load angle is 6°, the nth load is calculated when the bearing load angle is n×6°, and the last load (60th load) is calculated when the bearing load angle is 60×6°.

[0029] Measuring point M is set on the upper frame in the first direction (X) to measure the vibration waveform of the upper frame in the first direction (X), and measuring point N is set on the upper frame in the second direction (Y) to measure the vibration waveform of the upper frame in the second direction (Y). The deformation value x of point M in the first direction (X) is extracted from the upper frame analysis model. n The deformation value y of point N in the second direction Y. n The bearing load angle n×6° is extracted accordingly, and the value x is calculated. n / y n .

[0030] Standard load data includes a preset number of standard bearing load angles 6n obtained when the bearing load is a preset standard load of 1000N, and a deformation value x in the first direction X corresponding to each standard bearing load angle. n The deformation value y in the second direction Y. n and the deformation value x in the first direction X. n The deformation value y in the second direction Y n The first deformation value ratio x n / y n .

[0031] The structure of the upper frame of the semi-umbrella hydro-generator is as follows: Figure 2 As shown, the first direction (X-direction) and the second direction (Y-direction) are the horizontal extension directions of the upper frame of the semi-umbrella-type hydro-generator, and are perpendicular to each other. In step S11, the first vibration waveform data of the upper frame in the first and second directions are measured on site.

[0032] Step S12: Calculate the bearing load angle and bearing load at each first time point based on the first vibration waveform in the first direction and the second direction and the preset standard load data to form bearing load data.

[0033] In step S12, the deformation value x in the first X direction at each first time point t is first extracted based on the first vibration waveform in the first X direction and the second Y direction. t Deformation value y in the second direction Y t And calculate the ratio of the second deformation values ​​of the two, x. t / y tThen, find the closest first deformation value ratio x in the standard load data. n / y n .

[0034] Then, based on the ratio of the second deformation values ​​in the first direction and the second direction, and the ratio of the first deformation values ​​corresponding to each standard bearing load angle in the standard load data, an interpolation method is applied to calculate the bearing load angle θ at each first time point. The bearing load angle θ at any first time point t satisfies the following relationship:

[0035]

[0036] Then, based on the bearing load angle and the deformation values ​​in the first direction corresponding to each of the standard bearing load angles in the standard load data, an interpolation method is applied to calculate the deformation value in the first direction corresponding to the bearing load angle. Specifically, first, the deformation value x' in the first direction X is calculated when the bearing load angle is θ. Then, the bearing load angle 6n that is closest to the bearing load angle θ is found, and the deformation value x' in the first direction X corresponding to the bearing load angle 6n is obtained. 6n x' is obtained using interpolation based on the following relationship:

[0037]

[0038] Find the standard bearing load angle in the standard load data that is close to the bearing load angle, and the deformation value in the first direction corresponding to the standard bearing load angle. Calculate the bearing load based on the calculated deformation value in the first direction, the standard bearing load angle, and the corresponding deformation value in the first direction. The following relationship must be satisfied:

[0039]

[0040] The bearing load data for the upper frame of the semi-umbrella-type hydro-generator is formed by the bearing load angle and bearing load combination at each first time point. The bearing load data is saved in a txt file, with the first column being the time, the second column being the bearing load, and the third column being the bearing angle.

[0041] Step S13: Perform transient analysis on at least one target node within a preset load time period based on the bearing load data, and obtain the dynamic stress of the target node at each second time point within the preset load time period.

[0042] The bearing load data obtained in step S12 is read into the upper frame model of the hydro-generator. Two data tables are defined: the first data table, named LOAD_F, is used to store the bearing load amplitude, and the second data table, named LOAD_Theta, is used to store the bearing load angle. The number of rows in the data tables is the same as the number of rows of the read load data, and the data tables have two columns.

[0043] Before step S13, the bearing load data is read and split into a first data table storing time and bearing load, and a second data table storing time and bearing load angle. The step of calculating the bearing load and bearing load angle at the second time point using interpolation based on the bearing load data includes: calculating the bearing load at the second time point using interpolation based on the first data table; and calculating the bearing load angle at the second time point using interpolation based on the second data table. Specifically, a loop statement is written to assign the load data to the data tables LOAD_F and LOAD_Theta. The first column of the data tables stores the time, and the second column stores the load value and angle, respectively.

[0044] In step S13, as Figure 3 As shown, it includes:

[0045] Step S31: Determine each second time point within the preset load time period using a preset time step.

[0046] In this embodiment of the invention, the analysis type is set to transient analysis, and the transient analysis time step D_T is defined. The selection of the time step should be based on the unit's rotational speed and vibration frequency; the smaller the step size, the greater the computational load and the more accurate the result.

[0047] Once the time step is determined, the number of load steps to be calculated is N_T = T_tot / D_T, where T_tot is the total load time.

[0048] By using the coordinates of the stress nodes in the turbine generator's upper frame model, the stress node number N_Stress at the location of interest is extracted. The mesh generated using SOLID187 elements corresponds to one stress node.

[0049] Define an N_T row, 2 column data table named Time_Stress: one row to record the time for different load steps; and one row to record the stored stress corresponding to the time for different load steps.

[0050] Calculate the equivalent area A0 of the bearing:

[0051] A0=π×D×h

[0052] Where D is the diameter of the bearing and h is the height of the bearing.

[0053] Step S32: For any second time point T, calculate the bearing load and bearing load angle at the second time point T using interpolation based on the bearing load data.

[0054] Optionally, write a loop statement, taking any second time point T1 as an example:

[0055] The loop starts from i=1 and requires N_T load steps to be calculated in total;

[0056] During the i-th iteration, the time T1 at the second time point is equal to i*D_T;

[0057] The bearing load and bearing load angle at the second time point T1 are obtained by interpolating the first data table and the second data table respectively.

[0058] F1 = LOAD_F1(T1,1)

[0059] THETA1 = LOAD_THETA1(T1,1)

[0060] That is, the bearing load at the second time point T1 is calculated using interpolation based on the first data table; the bearing load angle at the second time point T1 is calculated using interpolation based on the second data table.

[0061] Step S33: Select all nodes on the cylindrical surface inside the bearing race of the upper frame model of the hydro-generator, and apply the bearing load to the bearing race based on the surface effect elements of all nodes.

[0062] Establish a local Cartesian coordinate system, with the Z-axis of the local Cartesian coordinate system rotated relative to the Z-axis of the global Cartesian coordinate system by the bearing load angle; select all nodes in the newly established local Cartesian coordinate system whose first direction coordinates on the inner side of the bearing race are between 0 and 2 / 3 of the bearing diameter.

[0063] When the bearing load is applied to the bearing race, the surface effect element of the node is selected; the average pressure on the bearing race at the second time point T1 is calculated: Pres0 = F1 / A0; the load is applied to the bearing race according to the average pressure.

[0064] Step S34: Calculate the dynamic stress of all grid points of the upper frame model of the hydro-generator and extract the dynamic stress of the target node.

[0065] After applying a load to the bearing race, the dynamic stress of all mesh points on the turbine generator frame model at the second time point T1 is calculated, and the dynamic stress of the target node is extracted. The second time point T1 is stored in the first column of the i-th row of the data table Time_Stress, and the stress of the target node N_Stress is stored in the second column of the data table Time_Stress. Then, the solution is iterated repeatedly for the (i+1)th time.

[0066] Output the Time_Stress data table to a txt file to obtain the dynamic stress at each point of interest on the upper rack.

[0067] This invention, through obtaining first vibration waveforms in the X-direction and Y-direction of the upper frame of a semi-umbrella-type hydro-generator, calculates the bearing load angle and bearing load at each first time point based on the first vibration waveforms in the first and second directions and preset standard load data, forming bearing load data. Based on the bearing load data, transient analysis is performed on at least one target node within a preset load time period to obtain the dynamic stress of the target node at each second time point within the preset load time period. This enables the calculation of the dynamic stress of each node on the upper frame of the semi-umbrella-type hydro-generator under different operating conditions, improving the accuracy of upper frame stress calculation and helping to maintain the operational stability of the unit.

[0068] Based on the same inventive concept, this invention provides a device for calculating the dynamic stress of the upper frame of a semi-umbrella-type hydro-generator. (See attached...) Figure 4 As shown, the device for calculating the dynamic stress on the upper frame of a semi-umbrella-type hydro-generator includes: a waveform acquisition module, a load data acquisition module, and a transient analysis module. Among them:

[0069] The waveform acquisition module is used to acquire the first vibration waveform of the upper frame of the semi-umbrella hydro-generator in the first and second directions, wherein the first and second directions are the horizontal extension directions of the upper frame of the semi-umbrella hydro-generator and are perpendicular to each other.

[0070] The load data acquisition module is used to calculate the bearing load angle and bearing load at each first time point based on the first vibration waveform in the first direction and the second direction and the preset standard load data, so as to form bearing load data.

[0071] The transient analysis module is used to perform transient analysis on at least one target node within a preset load time period based on the bearing load data, and to obtain the dynamic stress of the target node at each second time point within the preset load time period.

[0072] When implementing the embodiments of the present invention, the functions of each module can be implemented in one or more software and / or hardware. The apparatus of the above embodiments is used to implement the corresponding methods in the foregoing embodiments and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0073] Based on the same inventive concept, embodiments of the present invention also provide an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the method described in any of the above embodiments.

[0074] Based on the same inventive concept, embodiments of the present invention also provide a non-volatile computer storage medium storing at least one executable instruction that causes a processor to perform the method described in any of the above embodiments.

[0075] Figure 5 This embodiment illustrates a more specific hardware structure of an electronic device, which may include a processor 501, a memory 502, an input / output interface 503, a communication interface 504, and a bus 505. The processor 501, memory 502, input / output interface 503, and communication interface 504 are interconnected internally via the bus 505.

[0076] The processor 501 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present invention.

[0077] The memory 502 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 502 can store the operating system and other application programs. When the technical solution provided by the method embodiment of the present invention is implemented by software or firmware, the relevant program code is stored in the memory 502 and is called and executed by the processor 501.

[0078] Input / output interface 503 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touch screens, microphones, various sensors, etc., and output devices may include displays, speakers, vibrators, indicator lights, etc.

[0079] Communication interface 504 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0080] Bus 505 includes a pathway for transmitting information between various components of the device (e.g., processor 501, memory 502, input / output interface 503, and communication interface 504).

[0081] It should be noted that although the above-described device only shows the processor 501, memory 502, input / output interface 503, communication interface 504, and bus 505, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of the present invention, and does not necessarily include all the components shown in the figures.

[0082] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of this application as described above, which are not provided in detail for the sake of brevity.

[0083] This application is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the embodiments of this invention. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this invention should be included within the protection scope of this application.

Claims

1. A method for calculating the dynamic stress on the upper frame of a semi-umbrella-type hydro-generator, characterized in that, The method includes: Obtain the first vibration waveform of the upper frame of the semi-umbrella hydro-generator in the first and second directions, wherein the first and second directions are the horizontal extension directions of the upper frame of the semi-umbrella hydro-generator and are perpendicular to each other; Based on the first vibration waveform in the first direction and the second direction and the preset standard load data, the bearing load angle and bearing load at each first time point are calculated to form bearing load data; the preset standard load data is obtained in the following way: When the bearing load is a preset standard load, the second vibration waveforms in the first and second directions of the upper frame model of the hydro-generator are measured respectively. At preset angle intervals, based on the second vibration waveform, extract the deformation values ​​of a preset number of standard bearing load angles in the first and second directions of the upper frame model of the hydro-generator, as well as the ratio of the first deformation value in the first direction to the first deformation value in the second direction. The standard load data is formed by storing a preset number of standard bearing load angles, deformation values ​​in a first direction and a second direction corresponding to each standard bearing load angle, and the ratio of the first deformation values, including: Based on the first vibration waveform in the first and second directions, extract the deformation values ​​in the first and second directions at each first time point, and calculate the ratio of the second deformation values ​​of the two. Based on the ratio of the second deformation values ​​in the first direction and the second direction, and the ratio of the first deformation values ​​corresponding to each standard bearing load angle in the standard load data, the bearing load angle at each first time point is calculated using an interpolation method. Based on the bearing load angle and the deformation value in the first direction corresponding to each of the standard bearing load angles in the standard load data, the deformation calculation value in the first direction corresponding to the bearing load angle is calculated using an interpolation method. Find the standard bearing load angle that is close to the bearing load angle in the standard load data and the deformation value in the first direction corresponding to the standard bearing load angle. Calculate the bearing load based on the deformation calculation value in the first direction, the standard bearing load angle and the corresponding deformation value in the first direction. The bearing load data of the upper frame of the semi-umbrella hydro-generator is formed by the bearing load angle and bearing load combination at each first time point. Based on the bearing load data, a transient analysis is performed on at least one target node within a preset load time period to obtain the dynamic stress of the target node at each second time point within the preset load time period.

2. The method for calculating the dynamic stress of the upper frame of a semi-umbrella-type hydro-generator as described in claim 1, characterized in that, Before acquiring the vibration waveforms of the upper frame of the semi-umbrella-type hydro-generator in the first and second directions, the following steps are included: A model of the upper frame of the hydro-generator was constructed using modeling software. The upper frame was meshed using SOLID187 elements, and surface effect elements SURF154 were meshed on the cylindrical surface inside the bearing housing. Based on the model of the upper frame of the hydro-generator, a preset number of load data in the first and second directions are obtained under a preset standard load to obtain the standard load data.

3. The method for calculating the dynamic stress of the upper frame of a semi-umbrella-type hydro-generator as described in claim 1, characterized in that, The standard load data includes: a preset number of standard bearing load angles, deformation values ​​in the first and second directions corresponding to each standard bearing load angle, and the ratio of the first deformation values ​​in the first and second directions.

4. The method for calculating the dynamic stress of the upper frame of a semi-umbrella-type hydro-generator as described in claim 1, characterized in that, The step of performing transient analysis on at least one target node within a preset load time period based on the bearing load data, and obtaining the dynamic stress of the target node at each second time point within the preset load time period, includes: Determine each second time point within the preset load time period using a preset time step; For any second time point, the bearing load and bearing load angle at the second time point are calculated using interpolation based on the bearing load data; Select all nodes on the cylindrical surface inside the bearing race of the upper frame model of the hydro-generator, and apply the bearing load to the bearing race based on the surface effect elements of all nodes; Calculate the dynamic stress of all grid points on the upper frame model of the hydro-generator, and extract the dynamic stress of the target node.

5. The method for calculating the dynamic stress of the upper frame of a semi-umbrella-type hydro-generator as described in claim 4, characterized in that, Before performing transient analysis on at least one target node based on the bearing load data within a preset load time period, the method further includes: Read the bearing load data and split the bearing load data into a first data table of storage time and bearing load and a second data table of storage time and bearing load angle; The step of calculating the bearing load and bearing load angle at the second time point using interpolation based on the bearing load data includes: calculating the bearing load at the second time point using interpolation based on the first data table; and calculating the bearing load angle at the second time point using interpolation based on the second data table.

6. The method for calculating the dynamic stress of the upper frame of a semi-umbrella-type hydro-generator as described in claim 4, characterized in that, The selection of all nodes on the cylindrical surface inside the bearing housing ring of the upper frame model of the hydro-generator includes: Establish a local Cartesian coordinate system, and rotate the bearing load angle relative to the Z-axis of the global Cartesian coordinate system. In the newly established local Cartesian coordinate system, select all nodes whose first direction coordinates on the inner side of the bearing housing range from 0 to 2 / 2 of the bearing diameter.

7. A dynamic stress calculation device for the upper frame of a semi-umbrella-type hydro-generator, characterized in that, The device includes: The waveform acquisition module is used to acquire the first vibration waveform of the upper frame of the semi-umbrella hydro-generator in the first and second directions, wherein the first and second directions are the horizontal extension directions of the upper frame of the semi-umbrella hydro-generator and are perpendicular to each other. The load data acquisition module is used to calculate the bearing load angle and bearing load at each first time point based on the first vibration waveform in the first direction and the second direction and preset standard load data, thereby forming bearing load data; the preset standard load data is obtained through the following methods: When the bearing load is a preset standard load, the second vibration waveforms in the first and second directions of the upper frame model of the hydro-generator are measured respectively. At preset angle intervals, based on the second vibration waveform, extract the deformation values ​​of a preset number of standard bearing load angles in the first and second directions of the upper frame model of the hydro-generator, as well as the ratio of the first deformation value in the first direction to the first deformation value in the second direction. The standard load data is formed by storing a preset number of standard bearing load angles, deformation values ​​in a first direction and a second direction corresponding to each standard bearing load angle, and the ratio of the first deformation values, including: Based on the first vibration waveform in the first and second directions, extract the deformation values ​​in the first and second directions at each first time point, and calculate the ratio of the second deformation values ​​of the two. Based on the ratio of the second deformation values ​​in the first direction and the second direction, and the ratio of the first deformation values ​​corresponding to each standard bearing load angle in the standard load data, the bearing load angle at each first time point is calculated using an interpolation method. Based on the bearing load angle and the deformation value in the first direction corresponding to each of the standard bearing load angles in the standard load data, the deformation calculation value in the first direction corresponding to the bearing load angle is calculated using an interpolation method. Find the standard bearing load angle that is close to the bearing load angle in the standard load data and the deformation value in the first direction corresponding to the standard bearing load angle. Calculate the bearing load based on the deformation calculation value in the first direction, the standard bearing load angle and the corresponding deformation value in the first direction. The bearing load data of the upper frame of the semi-umbrella hydro-generator is formed by the bearing load angle and bearing load combination at each first time point. The transient analysis module is used to perform transient analysis on at least one target node within a preset load time period based on the bearing load data, and to obtain the dynamic stress of the target node at each second time point within the preset load time period.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1-6.

9. A computer storage medium, characterized in that, The storage medium stores at least one executable instruction that causes the processor to perform the method as described in any one of claims 1-6.

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