Shaft neck defect detection method and device of steam turbine rotor and electronic equipment

Abstract

The invention relates to a shaft neck defect detection method and device for a steam turbine rotor and electronic equipment, and the method comprises the steps: controlling an ultrasonic probe to move on an axial guide rail, controlling a shaft neck to rotate along an annular guide rail when the ultrasonic probe is at any position of the axial guide rail, and scanning the shaft neck through the ultrasonic probe, obtaining each piece of position information of the journal in the space; constructing a journal position matrix and a signal matrix, wherein each element in the journal position matrix and each element in the signal matrix have a mapping relationship; constructing an ideal three-dimensional image of the journal, if the amplitude of the ultrasonic signal is greater than a preset threshold in the signal matrix, obtaining position information mapped by the ultrasonic signal, and determining a defect position in the ideal three-dimensional image according to the mapped position information; and traversing each volume pixel in the ideal three-dimensional image, and counting the number of defect positions to obtain the defect volume. According to the invention, the accuracy of detecting the defects of the journal is improved.

Description

Technical Field

[0001] This application relates to the field of defect detection, and in particular to a method, apparatus and electronic equipment for detecting journal defects in a steam turbine rotor. Background Technology

[0002] Under long-term high-speed and alternating load conditions, turbine rotor journals are prone to micro-cracks and material deterioration defects. These defects can lead to mechanical failures, increased vibration, and ultimately, safety accidents. Current ultrasonic testing can only detect the presence of defects in the journals, but it cannot clearly determine the specific characteristics and size of the defects, making it difficult to determine subsequent maintenance strategies based on the specific information about the defects. Therefore, improving the accuracy of journal defect detection has become an urgent problem to be solved. Summary of the Invention

[0003] This application provides a method, apparatus, and electronic device for detecting journal defects in a steam turbine rotor, to at least address the problem of how to improve the accuracy of journal defect detection in related technologies.

[0004] In a first aspect, embodiments of this application provide a method for detecting journal defects in a steam turbine rotor, characterized in that the method is applied to a journal scanning system, the system including a circumferential guide rail and a shaft guide rail, the circumferential guide rail surrounding the end face of the journal, the shaft guide rail being parallel to the axial direction of the journal and connected to an ultrasonic probe; the method includes: The ultrasonic probe is controlled to move on the axial guide rail. When the ultrasonic probe is at any position on the axial guide rail, the journal is controlled to rotate along the circumferential guide rail and the ultrasonic probe is used to scan the journal to obtain information on each position of the journal in space. A journal position matrix is ​​constructed based on the position information, and a signal matrix is ​​determined based on each received ultrasound signal, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix; The defect shape is determined based on the location information using tensor quantization. Based on the dimensions of the journal, an ideal three-dimensional image of the journal is constructed. If the amplitude of the ultrasonic signal in the signal matrix is ​​greater than a preset threshold, the position information mapped by the ultrasonic signal is obtained. Based on the mapped position information and the defect shape, the defect position is determined in the ideal three-dimensional image. Traverse each volume pixel in the ideal three-dimensional image, count the number of defect locations, and determine the defect volume of the journal by the statistical result.

[0005] In one embodiment, the system further includes an axial stepper and a circumferential stepper. The ultrasonic probe is controlled to move along the axial guide rail. When the ultrasonic probe is at any position on the axial guide rail, the journal is controlled to rotate and the ultrasonic probe is used to scan the journal to obtain spatial position information for each position of the journal, including: Construct a journal coordinate system, wherein the journal coordinate system takes the center of the journal end face as the origin, the journal axis as the x-axis, and the direction from the high-pressure side to the low-pressure side of the turbine rotor as the positive direction of the x-axis. In the horizontal plane where the x-axis is located, rotate the x-axis 90° clockwise to determine the y-axis and the y-axis square, and define the z-axis as the axis that is perpendicular to the xy plane and points upward. Based on a first preset step size, the ultrasonic probe is controlled to move on the axial guide rail by the axial stepper; Based on the position of the ultrasonic probe on the axial guide rail, the first preset step size, and the length of the axial guide rail, the abscissa of each spatial position of the journal is determined; When the ultrasonic probe is at any position on the axial guide rail, the journal is controlled by the circumferential stepper to rotate half a revolution from the starting position in both clockwise and counterclockwise directions based on the second preset step size. During the rotation of the journal, the journal is scanned by an ultrasonic probe to obtain the detection distance of the journal. Based on the second preset step size and the detection distance, the depth coordinates and ordinates of each spatial position of the journal are determined. Based on the horizontal coordinate, the vertical coordinate, and the depth coordinate, the position information of each journal in space is obtained.

[0006] In one embodiment, determining the signal matrix based on each received ultrasound signal includes: Based on each of the aforementioned location information, the ultrasonic probe receives an ultrasonic signal returned from each spatial location and determines the depth of the ultrasonic probe in the journal based on the ultrasonic signal. Construct a signal matrix based on the depth.

[0007] In one embodiment, constructing an ideal three-dimensional image of the journal based on its dimensions includes: A three-dimensional image of the cube is constructed based on the end face radius of the journal and the length of the journal; In the three-dimensional image, a three-dimensional coordinate system is constructed with the lower left corner behind the cube as the origin and three mutually perpendicular sides originating from the origin as the x-axis, y-axis and z-axis. The x-axis is oriented in the same direction as the axis of the journal, the y-axis points to the front of the cube, the z-axis points to the top of the cube, and the cube is located in the first octant of the three-dimensional coordinate system. In the three-dimensional coordinate system, if the distance from any plane coordinate to the target coordinate in the ZY section of any cube is less than or equal to a preset distance threshold, then the volume pixel corresponding to the plane coordinate is retained. Based on the volume pixels, an ideal three-dimensional image of the journal is obtained.

[0008] In one embodiment, after determining the defect location in the ideal three-dimensional image based on the mapped location information and the defect shape, the method further includes: The defect location is rendered as the first color using a rendering tool; The remaining areas in the ideal 3D image are rendered with a second color, and the transparency of the remaining areas is reduced.

[0009] Secondly, embodiments of this application provide a journal scanning system for a steam turbine rotor, applied to the journal defect detection method for a steam turbine rotor in the first aspect. The system includes: a support component, a guide rail component, an ultrasonic probe, and a stepper. The supporting component includes a supporting bracket, a supporting base, and a limiting member. The bottom end of the supporting bracket is fixed to the supporting component, and the upper end of the supporting bracket is provided with a limiting member. The guide rail component includes a axial guide rail, a first annular guide rail, and a second annular guide rail. The first annular guide rail and the second annular guide rail are connected to the limiting member through a through hole, so that the first annular guide rail and the second annular guide rail surround the outer side of the journal end face attachment. The axial guide rail is disposed between the first annular guide rails on the two end faces of the journal and is located above the surface of the journal. The stepper includes a circumferential stepper and an axial stepper. The circumferential stepper is located within the first circumferential guide rail, and the axial stepper is connected to the axial guide rail. The ultrasonic probe is connected to the axial stepper, and the distance between the center of the ultrasonic probe and the surface of the journal is less than a preset threshold.

[0010] Thirdly, embodiments of this application provide a journal defect detection device for a steam turbine rotor. The device is applied to a journal scanning system, which includes a circumferential guide rail and a shaft guide rail. The circumferential guide rail surrounds the end face of the journal, and the shaft guide rail is parallel to the axial direction of the journal and connected to an ultrasonic probe. The device includes: The position information acquisition module is used to control the movement of the ultrasonic probe on the axial guide rail. When the ultrasonic probe is at any position on the axial guide rail, the module controls the journal to rotate along the circumferential guide rail and scans the journal through the ultrasonic probe to obtain the position information of the journal in space. The matrix determination module is used to construct a journal position matrix based on the position information and determine a signal matrix based on each received ultrasound signal, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix; The defect shape confirmation module is used to determine the defect shape based on the location information using a tensor quantization method. The defect location determination module is used to construct an ideal three-dimensional image of the journal based on the journal's dimensions. If the amplitude of the ultrasonic signal in the signal matrix is ​​greater than a preset threshold, the position information mapped by the ultrasonic signal is obtained, and the defect location is determined in the ideal three-dimensional image based on the mapped position information and the defect shape. The defect volume determination module is used to traverse each volume pixel in the ideal three-dimensional image, count the number of defect locations, and determine the statistical result as the defect volume of the journal.

[0011] Thirdly, embodiments of this application provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method for detecting journal defects of a steam turbine rotor as described in the first aspect above.

[0012] Fourthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for detecting journal defects of a steam turbine rotor as described in the first aspect above.

[0013] The method, apparatus, and electronic equipment for detecting journal defects in a steam turbine rotor provided in this application have at least the following technical effects.

[0014] The ultrasonic probe moves axially along the journal using an axial track, and the journal is selected using a circumferential track. During journal rotation and probe movement, the ultrasonic probe acquires positional information of the journal in space, allowing for the determination of defect locations based on its position. An ideal 3D model of the journal is constructed based on its dimensions. If the ultrasonic signal amplitude exceeds a preset threshold, the positional information mapped to the journal position matrix is ​​obtained, thus identifying the defect location. Tensor quantization is used to determine the defect shape. Based on the positional information and shape, the defect is precisely located in the ideal 3D image, accurately displaying the defect. By traversing each volume pixel in the 3D image and counting the number of defect locations, the volume of the defect in the journal can be determined. The 3D image provides precise information about the defect location and volume, offering crucial diagnostic criteria for maintenance.

[0015] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of a journal scanning system for a steam turbine rotor according to an exemplary embodiment; Figure 2 This is a schematic diagram illustrating a journal scanning system for a steam turbine rotor according to another exemplary embodiment; Figure 3 This is a schematic diagram of the connection of a stepper according to an exemplary embodiment; Figure 4 This is a schematic diagram illustrating the connection between a circumferential stepper and a circumferential drive battery according to an exemplary embodiment; Figure 5 This is a flowchart illustrating a method for detecting journal defects in a steam turbine rotor according to an exemplary embodiment; Figure 6 This is a schematic diagram of a journal coordinate system according to an exemplary embodiment; Figure 7 This is a schematic diagram of a three-dimensional image of a cube according to an exemplary embodiment; Figure 8 This is a schematic diagram of any ZY section according to an exemplary embodiment; Figure 9This is an ideal three-dimensional image of the journal shown according to an exemplary embodiment; Figure 10 This is a schematic diagram illustrating a defect in the journal according to an exemplary embodiment; Figure 11 This is a block diagram of a turbine rotor journal defect detection device according to an exemplary embodiment; Figure 12 This is a block diagram of an electronic device according to an exemplary embodiment.

[0017] In the above figures, the meanings of the reference numerals are as follows: 100. Supporting components; 4. Support bracket; 5. Support base; 9. Limiting components; 200. Guide rail components; 7. Axial guide rail; 6. First annular guide rail; 15. Second annular guide rail; 300. Stepper; 11. Axial stepper; 12. Axial drive battery; 13. Circumferential stepper. 14. Circular drive battery; 8. Locking nut, 16. Journal, 10. Ultrasonic probe, 1. Processing terminal, 2. Transmission line, 3. Steam turbine rotor. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0019] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0020] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0021] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects are in an "or" relationship. The terms "first," "second," and "third" used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0022] Figure 1 This is a schematic diagram of a journal scanning system for a steam turbine rotor according to an exemplary embodiment. Figure 2 This is a schematic diagram illustrating a journal scanning system for a steam turbine rotor according to another exemplary embodiment, as shown in the example. Figure 1 and Figure 2As shown, the turbine rotor 3 has journals 16 at both ends. A journal scanning system scans the journal 16 on one side. The journal scanning system for the turbine rotor includes: a support component 100, a guide rail component 200, an ultrasonic probe 10, and a stepper 300. The support component 100 includes a support bracket 4, a support base 5, and a limiting member 9. The bottom end of the support bracket 4 is connected to the support base 5, thus fixing the support bracket 4 to the support base 5. The upper end of the support bracket 4 is provided with the limiting member 9. The guide rail component 200 includes an axial guide rail 7, a first annular guide rail 6, and a second annular guide rail 15. The first annular guide rail 6 and the second annular guide rail 15 are connected to the limiting member 9 through through holes on the two annular guide rails and are fixed by a locking nut 8, so that the first annular guide rail 6 and the second annular guide rail 15 surround the outer surface of the journal near the end face of the journal 16. Axial guide rail 7 is positioned between two first annular guide rails 6 surrounding the outer surface of journal 16 and above the journal surface. The length of axial guide rail 7 is the same as the length of journal 16. Stepper 300 includes a circumferential stepper 13 and an axial stepper 11. The circumferential stepper 13 is located within the first annular guide rail 6. Axial stepper 13 is connected to axial guide rail 7 and to ultrasonic probe 10, allowing ultrasonic probe 10 to move with axial stepper 13. The distance between the center of ultrasonic probe 10 and journal surface is less than a preset threshold, ensuring that ultrasonic probe 10 is close to journal surface and thus guaranteeing detection accuracy.

[0023] Figure 3 This is a schematic diagram of the connection of a stepper according to an exemplary embodiment, as shown below. Figure 3 As shown, the circumferential stepper 13 is located within the first circumferential guide rail 6. The circumferential stepper 13 is connected to the circumferential drive battery 14 to provide power to the circumferential stepper 13. The axial stepper 11 is located on the axial guide rail 7 and is connected to the axial drive battery 12 to provide power to the axial stepper 11, allowing the axial stepper 11 to carry the ultrasonic probe 10 and move along the axial guide rail 7. Figure 4 This is a schematic diagram illustrating the connection between a circumferential stepper and a circumferential drive battery according to an exemplary embodiment, such as... Figure 4 As shown, the circumferential drive battery 14 and the circumferential stepper 13 are both located within the first circumferential guide rail 6, and the circumferential drive battery 14 is located on both sides of the circumferential stepper 13 to drive the circumferential stepper 13 to run.

[0024] In addition, such as Figure 1 As shown, the turbine rotor journal scanning system also includes a processing terminal 1. The processing terminal 1 is electrically connected to the ultrasonic probe 10 via a transmission line 2 to transmit the ultrasonic signal detected by the ultrasonic probe 10 to the processing terminal 1 for processing.

[0025] The turbine rotor journal scanning system uses a support component 100 to mount the guide rail component 200 onto the turbine rotor journal 16, and controls the rotation of the journal 16 through a circumferential stepper 13. The axial stepper 11 moves on the axial guide rail 7, so that the ultrasonic probe 10 performs a 360° scan on the journal 16.

[0026] Based on the above, this application provides a method for detecting journal defects in a steam turbine rotor.

[0027] In a first aspect, embodiments of this application provide a method for detecting journal defects in a steam turbine rotor. Figure 5 This is a flowchart illustrating a method for detecting journal defects in a steam turbine rotor according to an exemplary embodiment, as shown below. Figure 5 As shown, the method for detecting journal defects in a steam turbine rotor includes: Step S101: Control the ultrasonic probe to move on the axial guide rail. When the ultrasonic probe is at any position on the axial guide rail, control the journal to rotate along the circumferential guide rail and scan the journal through the ultrasonic probe to obtain the position information of the journal in space.

[0028] Figure 6 This is a schematic diagram of a journal coordinate system according to an exemplary embodiment, as shown below. Figure 6 As shown, the center of the journal end face is taken as the origin, the axis of the journal is taken as the x-axis, and the direction of the x-axis is from the high-pressure side to the low-pressure side of the turbine rotor as the positive direction of the x-axis; the x-axis is rotated 90° clockwise in the horizontal plane to determine the y-axis and the positive direction of the y-axis, and the axis perpendicular to the xy plane is taken as the z-axis. The journal coordinate system is constructed, and the coordinates of each spatial position of the journal are determined in the journal coordinate system.

[0029] In addition, the parameters of the axial stepper and the circumferential stepper need to be set. The parameter of the axial stepper is the first preset step size, which is the total number of steps to move along the axial guide rail. The parameter of the circumferential stepper is the second preset step size, which is the total number of steps to scan one revolution of the journal.

[0030] The ultrasonic probe moves along the axial guide rail using an axial stepper based on a first preset step size. When the axial stepper is at any position on the axial guide rail, the abscissa of each spatial position of the journal is determined based on the position of the ultrasonic probe on the axial guide rail, the first preset step size, and the length of the axial guide rail. For example, if the length of the axial guide rail is L1, the first preset step size is step_straight, and the axial stepper moves n steps along the axial guide rail... di If the number of steps is n, then the data for the axial direction is n. di *L1 / step_straight. Determine the abscissa of each spatial position of the journal based on the axial data, i.e., f. x =round(n di*L1 / step_straight), where f x It is the x-coordinate of the spatial location, round is the rounding function, and step_straight is the first preset step size.

[0031] When the ultrasonic probe is at any position on the axial guide rail, the journal is controlled by a circumferential stepper to rotate half a revolution clockwise and counterclockwise from the starting position according to the second preset step length. When the ultrasonic probe is at any position on the axial guide rail, the journal is controlled by a circumferential stepper to rotate 180° clockwise from the starting position, and then the journal is returned to the starting position. Then the journal is controlled by a circumferential stepper to rotate 180° counterclockwise from the starting position, and then the journal is returned to the starting position, completing one rotation of the journal.

[0032] During the rotation of the journal, the detection distance of the journal is obtained by scanning the journal with an ultrasonic probe. Based on the second preset step size and the detection distance, the depth coordinates and ordinates of each spatial position of the journal are determined.

[0033] During journal rotation, an ultrasonic probe scans the journal to obtain the ultrasonic signal reflected back from it, thereby determining the detection distance. Based on the second preset step size and the actual step size, the circumferential data for each spatial position is determined. Then, based on the circumferential data, the depth coordinates and ordinates of each spatial position of the journal are determined. For example: the detection distance is DR, the second preset step size is step_circle, and the circumferential stepper actually travels n... cj If the step is n, then the angle of the circumferential stepper scanning journal is n. cj *360° / step_circle. During clockwise rotation, the circumferential data is n. cj *360° / step_circle. During counter-clockwise rotation, the circumferential data is 360° - ncj * 360° / step_circle.

[0034] Determine the depth and ordinate of each spatial position of the journal based on the circumferential data. If the rotation direction is clockwise, the depth coordinate is: f z =DR ij +cos(n cj *360° / step_circle), where f z For depth coordinates, DR ij It is the detection range, n cj It represents the step size of the circumferential stepper, where step_circle is the second preset step size; the ordinate is f. y =DR ij +DR ij *sin(n cj*360° / step_circle), where f y DR is the vertical axis. ij It is the detection range, n cj It is the step size of the circular stepper, and step_circle is the second preset step size.

[0035] Based on the x-coordinate, y-coordinate, and depth coordinates, obtain the position information of the journal in space.

[0036] The abscissa of the ultrasonic probe on the axial guide rail is determined, and the depth coordinate and ordinate of each spatial position of the journal are determined on the abscissa to obtain the position information of each journal in space.

[0037] By scanning the journal with an axial stepper, a circumferential stepper, and an ultrasonic probe, the positional information of each spatial location of the journal is obtained, providing a basis for subsequent defect analysis.

[0038] Step S102: Construct a journal position matrix based on the position information, and determine the signal matrix based on each received ultrasound signal, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix.

[0039] A journal position matrix is ​​constructed based on the location information. Each position element in the journal position matrix maps a three-dimensional image of the journal in space.

[0040] Based on the positional information within the journal, the ultrasonic probe receives the ultrasonic signal returned from each spatial location. The probe's depth within the journal is determined based on these signals, and a signal matrix is ​​constructed according to this depth. Each element in the journal position matrix has a mapping relationship to each element in the signal matrix. For example, the journal position matrix is ​​as follows: The signal matrix is: In the journal position matrix, the signal corresponding to the first spatial position (fx1, fy1, fz1) is db1, and the signal corresponding to the second spatial position (fx2, fy2, fz2) is db2. That is, each spatial position in the journal position matrix is ​​uniquely mapped to an ultrasound signal.

[0041] By establishing a mapping relationship between the journal position matrix and the signal matrix, a prerequisite is provided for subsequent determination and confirmation.

[0042] Step S103: Determine the defect shape based on the location information using tensor quantization.

[0043] The location information obtained by the ultrasonic probe is used to initially determine the location of defects in the journal. Based on the location information of the defects, the length of the defects is obtained through the quantization method of the Gyration tensor, specifically satisfying the following formula:

[0044] in, It is a tensor, V m It is the initial volume of the defect. The coordinates of the geometric center of the i-th voxel in the α direction are... These are the coordinates of the geometric center of the defect in direction a. The coordinates of the geometric center of the i-th voxel in the β direction are... It is the geometric center coordinate of the defect in the β direction, and the α and β directions are any two of the x, y, and z directions.

[0045] The tensor of the defect, obtained through the above tensor formula, is a matrix. Three eigenvalues ​​of the defect tensor are then obtained: R1, R2, and R3. Based on these three eigenvalues, an ellipsoid is constructed to represent the initial shape of the defect. Therefore, the lengths of the ellipsoid in three mutually perpendicular directions in space are obtained, satisfying the following method: , and Where a is the length along the x-axis, b is the length along the y-axis, and c is the length along the z-axis.

[0046] Once the length of the defect in space is determined, its shape needs to be determined based on the elongation index, flattening index, and sphericity. The elongation index characterizes the slenderness of an ellipsoid or irregular shape, the flattening index characterizes the flattening of an ellipsoid or irregular shape, and sphericity characterizes the degree to which an ellipsoid approximates a sphere. After obtaining the lengths in different directions, the elongation index, flattening index, and sphericity of the defect are calculated, specifically satisfying the following conditions: Elongation index: EI = b / a, where EI is the elongation index, b is the length in the y-axis direction, and a is the length in the x-axis direction. The smaller the elongation index, the more slender the defect shape.

[0047] Flatness index: FI = c / b, where FI is the degree of flatness, b is the length in the y-axis direction, and c is the length in the z-axis direction. The smaller the flatness index, the flatter the defect.

[0048] Sphericity: , where R i R j It is the eigenvector of the tensor. The closer S1 is to 1, the more the defect approximates a sphere.

[0049] In one embodiment, the initial volume of the defect is determined to be 1000×100×100 mm based on the location information obtained by the ultrasonic probe, and the lengths in the three spatial directions are a=645, b=32, and c=32 mm, respectively. The length index is determined to be 0.05, and the flattening index is 1. The eigenvalues ​​of the tensor are 83334, 209, and 20, respectively, thus determining the sphericity to be 0.01, thereby confirming that the shape of the defect is a strip-shaped defect.

[0050] Based on the tensor quantization method, the shape of the defect in the journal can be initially determined, providing a basis for subsequent defect reconstruction and improving the accuracy of reconstruction.

[0051] Step S104: Based on the size of the journal, construct an ideal three-dimensional image of the journal. If the amplitude of an ultrasonic signal in the signal matrix is ​​greater than a preset threshold, obtain the position information mapped by the ultrasonic signal, and determine the defect location in the ideal three-dimensional image based on the mapped position information and the defect shape.

[0052] A 3D image of a cube is constructed based on the end face radius and length of the journal. For example, if the end face radius of the journal is R and the length of the journal is L, a cube with a width of 2R, a height of 2R, and a length of L is constructed, and a 3D image of the cube is obtained.

[0053] Figure 7 This is a schematic diagram of a three-dimensional image of a cube according to an exemplary embodiment. As shown in the figure, in the three-dimensional image, a three-dimensional coordinate system is constructed with the lower left corner behind the cube as the origin and three mutually perpendicular sides emanating from the origin as the x-axis, y-axis and z-axis. The x-axis is oriented in the same direction as the axis of the journal, the y-axis points towards the front of the cube, the z-axis points towards the top of the cube, and the cube is located in the first octant of the three-dimensional coordinate system.

[0054] In a 3D coordinate system, within any ZY section of a cube, if the distance from any planar coordinate to the target coordinate is less than or equal to a preset distance threshold, then the volume pixels corresponding to that planar coordinate are retained. The target coordinate is determined based on the center and radius of the journal end face. The preset distance threshold is the radius of the journal end face.

[0055] In one embodiment, Figure 8 This is a schematic diagram of any ZY section according to an exemplary embodiment, such as... Figure 8 As shown, the target coordinates are (R, R), which is the center of the journal end face. If the distance between any plane coordinate (Y, Z) and the target coordinate (R, R) satisfies: (ZR) 2 +(YR) 2 ≤R 2 If the coordinates are in that plane, then the volume pixels corresponding to those coordinates are retained.

[0056] Based on the retained volumetric pixels, an ideal 3D image of the journal is obtained. The ideal 3D image of the journal is a stereoscopic image identical to the actual journal, with the same radius, length, and axial direction. Figure 9 This is an ideal three-dimensional image of the journal shown according to an exemplary embodiment, such as Figure 9 As shown, the ideal 3D image presents itself as a cylinder in space. A journal coordinate system is constructed on the ideal 3D image, with the center of the end face of the journal in the ideal 3D image as the origin, the axis of the journal as the x-axis, and the x-axis obtained by rotating the x-axis 90° clockwise on the horizontal plane containing the x-axis, forming the xy plane, and the direction perpendicular to the xy plane and upward as the z-axis.

[0057] In the journal coordinate system, continuing with step S104, the amplitude of each ultrasonic signal in the signal matrix is ​​compared with a preset threshold. If the amplitude of the ultrasonic signal is greater than the preset threshold, the ultrasonic signal is determined to be the signal at the defect location. Based on the mapping relationship between the signal matrix and the journal position matrix, the corresponding position information in the journal position matrix is ​​determined according to the ultrasonic signal. Based on the defect shape and the position information determined in the journal position matrix, the spatial position in the ideal three-dimensional image that matches the position information is determined as the defect location. Since the ideal three-dimensional image of the journal is the same as the actual journal, the defect location in the ideal three-dimensional image is the actual defect in the journal. Furthermore, based on the defect shape, the position of the defect in the ideal three-dimensional image can be mapped more accurately. Optionally, the preset threshold is 2R. Figure 10 This is a schematic diagram illustrating a defect in the journal according to an exemplary embodiment, such as... Figure 10 As shown, the defect location is displayed in an ideal 3D image of the journal, and the defect location is shown as a hole.

[0058] By constructing an ideal three-dimensional model of the journal, the journal is visualized, and the location of the defect in the ideal three-dimensional model is determined through the journal position matrix and signal matrix, thereby achieving precise positioning of the journal defect.

[0059] Step S105: Traverse each volume pixel in the ideal three-dimensional image, count the number of defect locations, and determine the statistical result as the defect volume of the journal.

[0060] An ideal 3D image is composed of a number of volumetric pixels, and the size of these volumetric pixels varies at different resolutions. For example, at high resolutions, the size of volumetric pixels is very small, reaching sub-millimeter levels, thus enabling high-precision positioning. At low resolutions, the size of the volumetric image is larger. Therefore, given a known number of pixel volumes, the volume in an ideal 3D image can be determined by considering both the size and number of pixel volumes.

[0061] Continuing with step S105, the volume of the defect is determined by traversing each volume pixel in the ideal 3D image and counting the number of defect locations.

[0062] In one embodiment, an ideal 3D image consists of 10,000 volumetric pixels, each with a size of 0.1mm * 0.1mm * 0.1mm. If the number of volumetric pixels at the defect location in the ideal 3D image is 400, then the defect volume is V = 400 * 0.1 * 0.1 * 0.1, which is V = 0.4mm. 3 .

[0063] By statistically analyzing the volumetric pixels, the volume of defects on the journal can be determined, and further details of the defects can be identified based on the size of the volume, which can then be used to develop a maintenance plan.

[0064] Furthermore, after determining the defect location in the ideal three-dimensional image based on the mapped location information in step S104, the method further includes: In an ideal 3D image, 3D rendering technology renders defective areas with a first color and non-defective areas with a second color, while reducing the transparency of the non-defective areas. For example, rendering defective areas red means assigning the color of the voxel region (255, 0, 0), and rendering non-defective areas blue means assigning the color of the voxel region (0, 0, 255), while reducing the transparency of the non-defective areas, for example, to 50% of the original transparency.

[0065] By using 3D rendering technology, the defective and non-defective locations in the ideal 3D model of the journal are clearly distinguished. Different colors are used to differentiate between the defective and non-defective locations, and by reducing the transparency of the non-defective locations, the defects in the ideal 3D model are highlighted. This allows for further differentiation of the type and severity of defects, thereby enabling reasonable maintenance decisions.

[0066] In one embodiment, during the construction of the ideal 3D image of the journal, the corresponding matrix of the 3D image is determined based on the 3D image of the cube, and the voxel value is assigned to 0. In any ZY section, volume pixels whose distance from any planar coordinate to the target coordinate is less than or equal to a preset distance threshold are assigned a voxel value of 1 in the matrix, thus enabling the determination of the ideal 3D image of the journal from the 3D image of the cube. After determining the ideal 3D image of the journal, the signal matrix is ​​traversed to identify ultrasonic signals whose amplitude is less than or equal to a preset threshold. If the current ultrasonic signal corresponds to a defect in the journal, for example, if the preset threshold is 2R, and the ultrasonic signal amplitude is greater than or equal to 2R, then the ultrasonic signal is detecting a defect in the journal. Based on the mapping relationship between the signal matrix and the journal position matrix, the location of the defect is determined in the journal position matrix. Based on the location of the defect, the voxel value of the corresponding matrix is ​​assigned to 2, thus enabling the display of the defect location in the ideal 3D image of the journal. By traversing the voxel values ​​of the matrix and counting the number of voxel values ​​of 2, the volume of the defect in the journal can be determined based on the final count of the number of voxel values ​​of 2.

[0067] In summary, the turbine rotor journal defect detection method provided in this application achieves 360° scanning of the journal using a journal scanning system, determining the coordinates of each spatial position of the journal in the journal coordinate system to initially determine each spatial position of the journal. A journal position matrix is ​​constructed based on the determined positions, and a signal matrix is ​​constructed based on the ultrasonic signals. A mapping relationship is established between the two matrices. When a defect is determined through the signal matrix, its actual location is determined through the mapping relationship. Based on the actual location, the defect position can be accurately located in an ideal three-dimensional image of the journal, and the defect is visualized by color rendering, enabling detailed analysis of the defect. The defect positions in the ideal three-dimensional image are statistically analyzed, and the defect volume is determined based on the statistical results to quantify the defects in the journal. Further analysis of the defects based on their location and volume is possible, providing key data support for turbine rotor life assessment and the development of turbine rotor maintenance plans.

[0068] Secondly, embodiments of this application provide a device for detecting journal defects in a steam turbine rotor. Figure 11 This is a block diagram illustrating a turbine rotor journal defect detection device according to an exemplary embodiment. Figure 11 As shown, the device is used in a journal scanning system. The system includes a circumferential guide rail and an axial guide rail. The circumferential guide rail surrounds the end face of the journal, and the axial guide rail is parallel to the axis of the journal and connected to an ultrasound probe. The device includes: The position information acquisition module is used to control the movement of the ultrasonic probe on the axial guide rail. When the ultrasonic probe is at any position on the axial guide rail, the journal is controlled to rotate along the circumferential guide rail and the ultrasonic probe scans the journal to obtain the position information of the journal in space. The determination matrix module is used to construct the axial position matrix based on the position information and determine the signal matrix based on each received ultrasound signal, wherein each element in the axial position matrix has a mapping relationship with each element in the signal matrix; The defect shape confirmation module is used to determine the defect shape based on the location information using tensor quantization. The defect location determination module is used to construct an ideal three-dimensional image of the journal based on its dimensions. If the amplitude of an ultrasonic signal in the signal matrix is ​​greater than a preset threshold, the position information mapped by the ultrasonic signal is obtained. Based on the mapped position information and the defect shape, the defect location is determined in the ideal three-dimensional image. The defect volume determination module is used to traverse each volume pixel in the ideal 3D image, count the number of defect locations, and determine the defect volume of the journal as the result of the statistics.

[0069] It should be noted that the turbine rotor journal defect detection device provided in this embodiment is used to implement the above-described embodiments, and details already described will not be repeated. As used above, terms such as "module," "unit," and "subunit" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the above embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0070] Thirdly, embodiments of this application provide an electronic device, Figure 12 This is a block diagram illustrating an electronic device according to an exemplary embodiment. (e.g.) Figure 12 As shown, the electronic device may include a processor 81 and a memory 82 storing computer program instructions.

[0071] Specifically, the processor 81 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0072] The memory 82 may include a mass storage device for data or instructions. For example, and not limitingly, the memory 82 may include a hard disk drive (HDD), a floppy disk drive, a solid-state drive (SSD), flash memory, an optical disk drive, a magneto-optical disk drive, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 82 may include removable or non-removable (or fixed) media. Where appropriate, the memory 82 may be internal or external to a data processing device. In a particular embodiment, the memory 82 is non-volatile memory. In a particular embodiment, the memory 82 includes read-only memory (ROM) and random access memory (RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), an electrically alterable read-only memory (EAROM), or flash memory, or a combination of two or more of these. Where appropriate, the RAM can be Static Random-Access Memory (SRAM) or Dynamic Random-Access Memory (DRAM). DRAM can be Fast Page Mode Dynamic Random-Access Memory (FPMDRAM), Extended Data Out Dynamic Random-Access Memory (EDODRAM), Synchronous Dynamic Random-Access Memory (SDRAM), etc.

[0073] The memory 82 can be used to store or cache various data files that need to be processed and / or communicated, as well as possible computer program instructions executed by the processor 81.

[0074] The processor 81 reads and executes computer program instructions stored in the memory 82 to implement any of the turbine rotor journal defect detection methods in the above embodiments.

[0075] In one embodiment, the turbine rotor journal defect detection device may further include a communication interface 83 and a bus 80. Wherein, as... Figure 12 As shown, the processor 81, memory 82, and communication interface 83 are connected through bus 80 and complete communication with each other.

[0076] The communication interface 83 is used to enable communication between the various modules, devices, units, and / or equipment in the embodiments of this application. The communication interface 83 can also enable data communication with other components such as external devices, image / data acquisition devices, databases, external storage, and image / data processing workstations.

[0077] Bus 80 includes hardware, software, or both, that couples together the components of the turbine rotor journal defect detection device. Bus 80 includes, but is not limited to, at least one of the following: Data Bus, Address Bus, Control Bus, Expansion Bus, and Local Bus. For example, and not as a limitation, bus 80 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus, or other suitable buses, or a combination of two or more of these. Where appropriate, bus 80 may include one or more buses. Although specific buses are described and illustrated in the embodiments of this application, this application considers any suitable bus or interconnection.

[0078] Fourthly, embodiments of this application provide a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the method for detecting journal defects of a steam turbine rotor provided in the first aspect.

[0079] The readable storage medium may be more specifically adopted, including but not limited to: portable disk, hard disk, random access memory, read-only memory, erasable programmable read-only memory, optical storage device, magnetic storage device, or any suitable combination thereof.

[0080] In a possible implementation, the present invention can also be implemented as a program product comprising program code, which, when the program product is run on a terminal device, causes the terminal device to perform the steps of implementing the method for detecting journal defects in a steam turbine rotor provided in the first aspect.

[0081] The program code for executing the present invention can be written in any combination of one or more programming languages. The program code can be executed entirely on the user device, partially on the user device, as a standalone software package, partially on the user device and partially on a remote device, or entirely on a remote device.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for detecting journal defects in a steam turbine rotor, characterized in that, The method is applied to a journal scanning system, the system including an ultrasonic probe, a circumferential guide rail, and a axial guide rail. The circumferential guide rail surrounds the end face of the journal, and the axial guide rail is parallel to the axial direction of the journal and connected to the ultrasonic probe. The method includes: The ultrasonic probe is controlled to move on the axial guide rail. When the ultrasonic probe is at any position on the axial guide rail, the journal is controlled to rotate along the circumferential guide rail and the ultrasonic probe is used to scan the journal to obtain information on each position of the journal in space. A journal position matrix is ​​constructed based on the position information, and a signal matrix is ​​determined based on each received ultrasound signal, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix; The defect shape is determined based on the location information using tensor quantization. Based on the dimensions of the journal, an ideal three-dimensional image of the journal is constructed. If the amplitude of the ultrasonic signal in the signal matrix is ​​greater than a preset threshold, the position information mapped by the ultrasonic signal is obtained. Based on the mapped position information and the defect shape, the defect position is determined in the ideal three-dimensional image. Traverse each volume pixel in the ideal three-dimensional image, count the number of defect locations, and determine the defect volume of the journal by the statistical result.

2. The method for detecting journal defects in a steam turbine rotor according to claim 1, characterized in that, The system also includes an axial stepper and a circumferential stepper. The ultrasonic probe is controlled to move along the axial guide rail. When the ultrasonic probe is at any position on the axial guide rail, the journal is controlled to rotate and the ultrasonic probe scans the journal to obtain position information of the journal in space, including: Construct a journal coordinate system, wherein the journal coordinate system takes the center of the journal end face as the origin, the journal axis as the x-axis, and the direction from the high-pressure side to the low-pressure side of the turbine rotor as the positive direction of the x-axis. In the horizontal plane where the x-axis is located, rotate the x-axis 90° clockwise to determine the y-axis and the y-axis square, and define the z-axis as the axis that is perpendicular to the xy plane and points upward. Based on a first preset step size, the ultrasonic probe is controlled to move on the axial guide rail by the axial stepper; Based on the position of the ultrasonic probe on the axial guide rail, the first preset step size, and the length of the axial guide rail, the abscissa of each spatial position of the journal is determined; When the ultrasonic probe is at any position on the axial guide rail, the journal is controlled by the circumferential stepper to rotate half a revolution from the starting position in both clockwise and counterclockwise directions based on the second preset step size. During the rotation of the journal, the journal is scanned by an ultrasonic probe to obtain the detection distance of the journal. Based on the second preset step size and the detection distance, the depth coordinates and ordinates of each spatial position of the journal are determined. Based on the horizontal coordinate, the vertical coordinate, and the depth coordinate, the position information of each journal in space is obtained.

3. The method for detecting journal defects in a steam turbine rotor according to claim 2, characterized in that, The step of determining the signal matrix based on each received ultrasound signal includes: Based on each of the aforementioned location information, the ultrasonic probe receives an ultrasonic signal returned from each spatial location and determines the depth of the ultrasonic probe in the journal based on the ultrasonic signal. Construct a signal matrix based on the depth.

4. The method for detecting journal defects in a steam turbine rotor according to claim 1, characterized in that, Constructing an ideal three-dimensional image of the journal based on its dimensions includes: A three-dimensional image of the cube is constructed based on the end face radius of the journal and the length of the journal; In the three-dimensional image, a three-dimensional coordinate system is constructed with the lower left corner behind the cube as the origin and three mutually perpendicular sides originating from the origin as the x-axis, y-axis and z-axis. The x-axis is oriented in the same direction as the axis of the journal, the y-axis points to the front of the cube, the z-axis points to the top of the cube, and the cube is located in the first octant of the three-dimensional coordinate system. In the three-dimensional coordinate system, if the distance from any plane coordinate to the target coordinate in the ZY section of any cube is less than or equal to a preset distance threshold, then the volume pixel corresponding to the plane coordinate is retained. Based on the volume pixels, an ideal three-dimensional image of the journal is obtained.

5. The method for detecting journal defects in a steam turbine rotor according to claim 1, characterized in that, After determining the defect location in the ideal three-dimensional image based on the mapped location information and the defect shape, the method further includes: The defect location is rendered as the first color using a rendering tool; The remaining areas in the ideal 3D image are rendered with a second color, and the transparency of the remaining areas is reduced.

6. A journal scanning system for a steam turbine rotor, applied to the journal defect detection method for a steam turbine rotor according to any one of claims 1 to 5, the system comprising: Support components, guide rail components, ultrasonic probe, stepper; The supporting component includes a supporting bracket, a supporting base, and a limiting member. The bottom end of the supporting bracket is fixed to the supporting component, and the upper end of the supporting bracket is provided with a limiting member. The guide rail component includes an axial guide rail, a first annular guide rail, and a second annular guide rail. The first annular guide rail and the second annular guide rail are connected to the limiting member through a through hole so that the first annular guide rail and the second annular guide rail surround the end face of the journal. The axial guide rail is disposed between the first annular guide rails on the two end faces of the journal and is located above the surface of the journal. The stepper includes a circumferential stepper and an axial stepper. The circumferential stepper is located within the first circumferential guide rail, and the axial stepper is connected to the axial guide rail. The ultrasonic probe is connected to the axial stepper, and the distance between the center of the ultrasonic probe and the surface of the journal is less than a preset threshold.

7. A device for detecting journal defects in a steam turbine rotor, characterized in that, The device is used in a journal scanning system, the system including a circumferential guide rail and a axial guide rail, the circumferential guide rail surrounding the end face of the journal, the axial guide rail being parallel to the axial direction of the journal and connected to an ultrasound probe; the device includes: The position information acquisition module is used to control the movement of the ultrasonic probe on the axial guide rail. When the ultrasonic probe is at any position on the axial guide rail, the module controls the journal to rotate along the circumferential guide rail and scans the journal through the ultrasonic probe to obtain the position information of the journal in space. The matrix determination module is used to construct a journal position matrix based on the position information and determine a signal matrix based on each received ultrasound signal, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix; The defect shape confirmation module is used to determine the defect shape based on the location information using a tensor quantization method. The defect location determination module is used to construct an ideal three-dimensional image of the journal based on the journal's dimensions. If the amplitude of the ultrasonic signal in the signal matrix is ​​greater than a preset threshold, the position information mapped by the ultrasonic signal is obtained, and the defect location is determined in the ideal three-dimensional image based on the mapped position information and the defect shape. The defect volume determination module is used to traverse each volume pixel in the ideal three-dimensional image, count the number of defect locations, and determine the statistical result as the defect volume of the journal.

8. An electronic device, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method for detecting journal defects of a steam turbine rotor as described in any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method for detecting journal defects of a steam turbine rotor as described in any one of claims 1 to 7.

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