A method, apparatus, and electronic equipment for detecting journal defects in steam turbine rotors.

Abstract

This application relates to a method, apparatus, and electronic device for detecting journal defects in a steam turbine rotor. The method includes: controlling an ultrasonic probe to move along a axial guide rail; when the ultrasonic probe is at any position on the axial guide rail, controlling the journal to rotate along the circumferential guide rail and scanning the journal with the ultrasonic probe to obtain position information of the journal in space; constructing a journal position matrix and a signal matrix, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix; constructing 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, obtaining the position information mapped by the ultrasonic signal; determining the defect location in the ideal three-dimensional image based on the mapped position information; and traversing each volume pixel in the ideal three-dimensional image to count the number of defect locations and obtain the defect volume. This application improves the accuracy of journal defect detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of defect detection, and particularly to a steam turbine rotor journal defect detection method and device and electronic equipment. BACKGROUND

[0002] The journal of a steam turbine rotor is prone to micro-cracks and material cracking defects under long-term high-speed rotation and alternating load conditions. These defects can cause mechanical failure and vibration intensification, thereby causing safety accidents. In the prior art, defects in the journal can only be detected by ultrasonic detection, but the specific characteristics and volume of the defects cannot be clearly known, so it is difficult to determine the subsequent maintenance strategy based on the specific information of the defects. Therefore, how to improve the defect detection accuracy of the journal has become a problem to be solved. SUMMARY

[0003] The embodiments of the present application provide a steam turbine rotor journal defect detection method, device and electronic equipment to at least solve the problem of how to improve the defect detection accuracy of the journal in the related art.

[0004] In a first aspect, the embodiments of the present application provide a steam turbine rotor journal defect detection method, characterized in that the method is applied to 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, the axial guide rail is parallel to the axial direction of the journal, and is connected with an ultrasonic probe; the method comprises:

[0005] controlling the ultrasonic probe to move on the axial guide rail, when the ultrasonic probe is at any position on the axial guide rail, controlling the journal to rotate along the circumferential guide rail and scanning the journal by the ultrasonic probe to obtain position information of the journal at each position in space;

[0006] constructing a journal position matrix according to the position information, and determining a signal matrix according to each received ultrasonic signal, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix;

[0007] determining a defect shape according to the position information by a tensor quantization method;

[0008] constructing an ideal three-dimensional image of the journal based on the size of the journal, if there is an ultrasonic signal with an amplitude 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 the defect shape;

[0009] traversing each volume pixel in the ideal three-dimensional image, counting the number of defect positions, and determining the counting result as the defect volume of the journal.

[0010] In an embodiment, the system further comprises an axial stepper and a circumferential stepper, the control unit controls the ultrasonic probe to move on the axial guide rail, controls the journal to rotate and scan the journal by the ultrasonic probe when the ultrasonic probe is at any position of the axial guide rail, and obtains the position information of each position of the journal in space, including:

[0011] constructing a journal coordinate system, wherein the journal coordinate system takes the center of the journal end face as the origin, takes the journal axial direction as the x-axis, and takes the direction from the high-pressure side to the low-pressure side of the steam turbine rotor as the positive direction of the x-axis, rotates the x-axis 90° clockwise in the horizontal plane of the x-axis to determine the y-axis and the positive direction of the y-axis, and takes the direction perpendicular to the x-y plane and upward as the z-axis;

[0012] controlling the ultrasonic probe to move on the axial guide rail by the axial stepper based on a first preset step length;

[0013] determining the x-coordinate of each spatial position of the journal according to the position of the ultrasonic probe on the axial guide rail, the first preset step length, and the length of the axial guide rail;

[0014] controlling the journal to rotate half a circle in the clockwise direction and the counterclockwise direction respectively from the starting position based on a second preset step length by the circumferential stepper when the ultrasonic probe is at any position of the axial guide rail;

[0015] scanning the journal by the ultrasonic probe during the rotation of the journal to obtain the detection distance of the journal, and determining the depth coordinate and the longitudinal coordinate of each spatial position of the journal based on the second preset step length and the detection distance;

[0016] obtaining the position information of each position of the journal in space according to the x-coordinate, the longitudinal coordinate, and the depth coordinate.

[0017] In an embodiment, the determining of the signal matrix according to each received ultrasonic signal comprises:

[0018] based on the ultrasonic signal received by the ultrasonic probe at each spatial position returned by each position information, determining the depth detected by the ultrasonic probe in the journal according to the ultrasonic signal;

[0019] constructing a signal matrix according to the depth.

[0020] In an embodiment, the constructing of the ideal three-dimensional image of the journal based on the size of the journal comprises:

[0021] constructing a three-dimensional image of a cubic body based on the end face radius of the journal and the length of the journal;

[0022] In the three-dimensional image, a lower left corner behind the cube is taken as an origin, and three mutually perpendicular edges from the origin are taken as an x-axis, a y-axis and a z-axis, thereby constructing a three-dimensional coordinate system, wherein a direction of the x-axis is the same as an axial direction of the journal, a y-axis direction points to a front surface of the cube, a z-axis direction points to an upper surface of the cube, and the cube is located in a first octant of the three-dimensional coordinate system;

[0023] In the three-dimensional coordinate system, if a distance from any plane coordinate to a target coordinate is less than or equal to a preset distance threshold in a Z-Y cross section of any cube, a volume pixel corresponding to the plane coordinate is reserved;

[0024] Based on the volume pixel, an ideal three-dimensional image of the journal is obtained.

[0025] In an embodiment, after the defect position is determined in the ideal three-dimensional image according to the mapped position information and the defect shape, the method further comprises:

[0026] The defect position is rendered into a first color by a rendering tool;

[0027] Remaining positions in the ideal three-dimensional image are rendered into a second color, and transparency of the remaining positions is reduced.

[0028] In a second aspect, an embodiment of the present application provides a journal scanning system of a steam turbine rotor, which is applied to the journal defect detection method of the steam turbine rotor in the first aspect, and the system comprises a support component, a guide rail component, an ultrasonic probe and a stepper.

[0029] The support component comprises a support bracket, a support base and a limiting piece, a bottom end of the support bracket is fixed to the support component, and an upper end of the support bracket is provided with the limiting piece;

[0030] The guide rail component comprises an axial guide rail, a first ring guide rail and a second ring guide rail, the first ring guide rail and the second ring guide rail pass through the limiting piece through a through hole, so that the first ring guide rail and the second ring guide rail are arranged around an outer surface of the journal adjacent to end surfaces of the journal, and the axial guide rail is arranged between the first ring guide rail and the second ring guide rail on the surface of the journal;

[0031] The stepper comprises a ring stepper and an axial stepper, the ring stepper is located in the first ring guide rail, and the axial stepper is connected with the axial guide rail;

[0032] The ultrasonic probe is connected with the axial stepper, and a distance between a center of the ultrasonic probe and the surface of the journal is less than a preset threshold.

[0033] In a third aspect, the embodiments of the present application provide a shaft neck defect detection device of a steam turbine rotor, which is applied to a shaft neck scanning system, the system comprising a circumferential guide rail and an axial guide rail, the circumferential guide rail being arranged around an end surface of a shaft neck, the axial guide rail being parallel to an axial direction of the shaft neck and being connected with an ultrasonic probe; the device comprising:

[0034] a position information acquisition module configured to control the ultrasonic probe to move on the axial guide rail, and control the shaft neck to rotate along the circumferential guide rail and be scanned by the ultrasonic probe at any position of the axial guide rail to obtain position information of the shaft neck at each position in space;

[0035] a matrix determination module configured to construct a shaft neck position matrix according to the position information, and determine a signal matrix according to each received ultrasonic signal, wherein each element in the shaft neck position matrix has a mapping relationship with each element in the signal matrix;

[0036] a defect shape confirmation module configured to determine a defect shape according to the position information by using a tensor quantization method;

[0037] a defect position determination module configured to construct an ideal three-dimensional image of the shaft neck based on a size of the shaft neck, obtain position information mapped by the ultrasonic signal if there is an amplitude of the ultrasonic signal greater than a preset threshold in the signal matrix, and determine a defect position in the ideal three-dimensional image according to the mapped position information and the defect shape;

[0038] a defect volume determination module configured to traverse each volume pixel in the ideal three-dimensional image, count a number of the defect positions, and determine a result of the counting as a defect volume of the shaft neck.

[0039] In a third aspect, the embodiments of the present application provide a computer device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the shaft neck defect detection method of the steam turbine rotor according to the first aspect.

[0040] In a fourth aspect, the embodiments of the present application provide a computer readable storage medium, which stores a computer program, and the program is executable on a processor to implement the shaft neck defect detection method of the steam turbine rotor according to the first aspect.

[0041] The shaft neck defect detection method, device and electronic device provided by the embodiments of the present application at least have the following technical effects.

[0042] The ultrasonic probe is controlled to move in the axial direction of the journal by an axial track, and the journal is controlled to select by a ring track, and each position information of the journal in space is obtained by the ultrasonic probe during the rotation of the journal and the movement of the ultrasonic probe, so that the position of the ultrasonic probe in space can be determined. The ideal three-dimensional model of the journal is constructed according to the size of the journal, and the position information of the ultrasonic signal mapping the journal position matrix is obtained when the amplitude of the ultrasonic signal is greater than a preset threshold value determined by a signal matrix, so as to determine the defect position in the journal. The defect shape is determined by a tensor quantization method, and the defect position is accurately positioned in the ideal three-dimensional image according to the position information and the defect shape, so that the defect is accurately displayed in the three-dimensional image. And by traversing each volume pixel in the three-dimensional image, the number of defect positions is counted, so that the volume of the defect in the journal can be determined according to the determined number, and the position and volume of the defect can be accurately known by the three-dimensional image, so as to provide a judgment condition for maintenance.

[0043] The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description of the application and from the drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS

[0044] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and serve to explain the application. In the drawings:

[0045] Figure 1 is a schematic diagram of a journal scanning system of a steam turbine rotor according to an exemplary embodiment;

[0046] Figure 2 is a schematic diagram of a journal scanning system of a steam turbine rotor according to another exemplary embodiment;

[0047] Figure 3 is a connection diagram of a stepper according to an exemplary embodiment;

[0048] Figure 4 is a connection diagram of a ring stepper and a ring drive battery according to an exemplary embodiment;

[0049] Figure 5 is a flow chart of a journal defect detection method of a steam turbine rotor according to an exemplary embodiment;

[0050] Figure 6 is a schematic diagram of a journal coordinate system according to an exemplary embodiment;

[0051] Figure 7is a schematic diagram of a three-dimensional image of a cube according to an exemplary embodiment;

[0052] Figure 8 is a schematic diagram of any Z-Y cross section according to an exemplary embodiment;

[0053] Figure 9 is a schematic diagram of an ideal three-dimensional image of a journal according to an exemplary embodiment;

[0054] Figure 10 is a schematic diagram of a journal with defects according to an exemplary embodiment;

[0055] Figure 11 is a block diagram of a journal defect detection device for a steam turbine rotor according to an exemplary embodiment;

[0056] Figure 12 is a block diagram of an electronic device according to an exemplary embodiment.

[0057] In the above drawings, the meanings of the reference numerals are as follows:

[0058] 100, support member, 4, support bracket, 5, support base, 9, limiting piece;

[0059] 200, guide rail member, 7, axial guide rail, 6, first ring guide rail, 15, second ring guide rail;

[0060] 300, stepper, 11, axial stepper, 12, axial drive battery, 13, ring stepper,

[0061] 14, ring drive battery;

[0062] 8, locking nut, 16, journal, 10, ultrasonic probe, 1, processing terminal, 2, transmission line, 3, steam turbine rotor. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is described and explained below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. Based on the examples provided in the present application, all other examples obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0064] It is apparent that the drawings in the following description merely show some examples or embodiments of the present application, and the present application can be applied to other similar situations without creative labor by those skilled in the art based on these drawings. In addition, it can be understood that although the efforts made in the development process can be complex and lengthy, some design, manufacture or production changes made on the basis of the technical content disclosed in the present application by those skilled in the art related to the content disclosed in the present application are only routine technical means and should not be understood as insufficient disclosure of the content disclosed in the present application.

[0065] Reference to "an embodiment" in this disclosure means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of other embodiments. It is explicitly contemplated that embodiments described herein can be combined with other embodiments in their various permutations and combinations without necessarily reserving each and every permutation or combination for a single embodiment.

[0066] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the ordinary meaning commonly understood by one of ordinary skill in the art to which the present application pertains. The terms "a", "an", "one", "this", and similar terms as used in the application do not denote a limitation of quantity but rather denote the presence of at least one of the referenced item. The terms "include", "comprise", "have", and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a list of steps or modules (units) is not necessarily limited to those listed steps or units, but can include additional steps or units not expressly listed or can include steps or units inherent to such process, method, product, or apparatus. The terms "connected", "coupled", and similar terms as used in the application are not limited to direct or physical connections, but can include indirect connections or couplings, whether or not they are direct or indirect. The term "multiple" refers to two or more. The term "and / or" describes an associated relationship between associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that A exists alone, A and B exist together, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects. The terms "first", "second", "third", and the like as used in the application merely distinguish similar objects, and do not represent a specific order for the objects.

[0067] Figure 1 is a schematic view of a shaft neck scanning system of a steam turbine rotor according to an exemplary embodiment, Figure 2is a schematic view of a shaft neck scanning system of a steam turbine rotor according to another exemplary embodiment, as shown in Figure 1 and Figure 2 As shown in the figure, the steam turbine rotor 3 has two shaft necks 16, and the shaft neck scanning system scans the shaft neck 16 on one side. The shaft neck scanning system of the steam turbine rotor comprises a support component 100, a guide rail component 200, an ultrasonic probe 10 and a stepper 300. The support component 100 comprises a support bracket 4, a support base 5 and a limiting piece 9. The bottom end of the support bracket 4 is connected to the support base 5, so that the support bracket 4 is fixed to the support base 5. The upper end of the support bracket 4 is provided with the limiting piece 9. The guide rail component 200 comprises an axial guide rail 7, a first circumferential guide rail 6 and a second circumferential guide rail 15. The first circumferential guide rail 6 and the second circumferential guide rail 15 are connected to the limiting piece 9 through through holes on the two circumferential guide rails, and the two circumferential guide rails are fixed by a locking nut 8, so that the first circumferential guide rail 6 and the second circumferential guide rail 15 are wrapped around the outer surface of the shaft neck 16 near the end surface of the shaft neck 16. The axial guide rail 7 is arranged between the two first circumferential guide rails 6 wrapped around the outer surface of the shaft neck 16 and above the surface of the shaft neck 16, and the length of the axial guide rail 7 is the same as the length of the shaft neck 16. The stepper 300 comprises a circumferential stepper 13 and an axial stepper 11, and the circumferential stepper 13 is located in the first circumferential guide rail 6. The axial stepper 13 is connected to the axial guide rail 7 and connected to the ultrasonic probe 10, so that the ultrasonic probe 10 moves with the axial stepper 13. The distance between the center of the ultrasonic probe 10 and the surface of the shaft neck is less than a preset threshold, so that the ultrasonic probe 10 is close to the surface of the shaft neck, thereby ensuring the accuracy of detection.

[0068] Figure 3 is a connection diagram of a stepper according to an exemplary embodiment, as shown in Figure 3 The circumferential stepper 13 is located in the first circumferential guide rail 6, and the circumferential stepper 13 is connected to the circumferential drive battery 14 to provide power to the circumferential stepper 13 through the circumferential drive battery 14. The axial stepper 11 is located above the axial guide rail 7, and the axial stepper 11 is connected to the axial drive battery 12 to provide power to the axial stepper 11 through the axial drive battery, so that the axial stepper 11 carries the ultrasonic probe 10 to move on the axial guide rail 7. Figure 4 is a connection diagram of a circumferential stepper and a circumferential drive battery according to an exemplary embodiment, as shown in Figure 4 The circumferential drive battery 14 and the circumferential stepper 13 are both located in 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 operate.

[0069] In addition, as shown in Figure 1As shown, the shaft neck scanning system of the steam turbine rotor further comprises a processing terminal 1, and the processing terminal 1 is electrically connected with the ultrasonic probe 10 through a transmission line 2 to transmit the ultrasonic signal detected by the ultrasonic probe 10 to the processing terminal 1 for processing.

[0070] The shaft neck scanning system of the steam turbine rotor installs the guide rail component 200 on the shaft neck 16 of the steam turbine rotor through the support component 100, controls the rotation of the shaft neck 16 through the circumferential stepper 13, and moves the ultrasonic probe 10 on the axial guide rail 7 through the axial stepper 11, so that the ultrasonic probe 10 scans the shaft neck 16 by 360°.

[0071] Based on the above, the embodiment of the present application provides a shaft neck defect detection method of a steam turbine rotor.

[0072] In a first aspect, the embodiment of the present application provides a shaft neck defect detection method of a steam turbine rotor, Figure 5 is a flow chart of the shaft neck defect detection method of the steam turbine rotor according to an exemplary embodiment, as shown in the figure, Figure 5 As shown, the shaft neck defect detection method of the steam turbine rotor comprises:

[0073] In step S101, the ultrasonic probe is controlled to move on the axial guide rail, and when the ultrasonic probe is at any position on the axial guide rail, the shaft neck is controlled to rotate along the circumferential guide rail and is scanned by the ultrasonic probe to obtain the position information of the shaft neck at each position in space.

[0074] Figure 6 is a schematic diagram of the shaft neck coordinate system according to an exemplary embodiment, as shown in the figure, Figure 6 As shown, the center of the end surface of the shaft neck is taken as the origin, the axial direction of the shaft neck is taken as the x-axis, and the direction from the high-pressure side of the steam turbine rotor to the low-pressure side is taken as the positive direction of the x-axis; the x-axis is rotated by 90° clockwise in the horizontal plane to determine the y-axis and the positive direction of the y-axis, and the z-axis perpendicular to the x-y plane is determined to construct the shaft neck coordinate system, and the coordinates of each spatial position of the shaft neck are determined in the shaft neck coordinate system.

[0075] In addition, the parameters of the axial stepper and the circumferential stepper also need to be set. The parameter of the axial stepper is the first preset step length, which is the total number of steps of the movement on the axial guide rail. The parameter of the circumferential stepper is the second preset step length, which is the total number of steps of one scanning circle of the shaft neck.

[0076] The ultrasonic probe is controlled to move on the axial guide rail by the axial stepper based on the first preset step length. When the axial stepper is at any position on the axial guide rail, the horizontal coordinate of each spatial position of the shaft neck is determined according to the position of the ultrasonic probe on the axial guide rail, the first preset step length and the length of the axial guide rail. For example, the length of the axial guide rail is L1, the first preset step length is step_straight, the axial stepper moves on the axial guide rail for n diIf 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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 cjis the step length of the circumferential stepper, and step_circle is a second preset step length y =DR ij +DR ij *sin(n cj *360° / step_circle), where f y is the ordinate, DR ij is the detection distance, n cj is the step length of the circumferential stepper, and step_circle is a second preset step length.

[0081] According to the abscissa, ordinate and depth coordinate, the position information of each position of the journal in space is obtained.

[0082] The abscissa of the position of the ultrasonic probe on the axial guide rail is determined, and the depth coordinate and the ordinate of each spatial position of the journal at the abscissa are determined, to obtain the position information of each position of the journal in space.

[0083] The journal is scanned by the axial stepper, the circumferential stepper and the ultrasonic probe to obtain the position information of each spatial position of the journal, which provides a basis for subsequent defect analysis.

[0084] In step S102, a journal position matrix is constructed according to the position information, and a signal matrix is determined according to each received ultrasonic signal, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix.

[0085] The journal position matrix is constructed according to the position information, and each position element in the journal position matrix maps a three-dimensional image of the journal in space.

[0086] Based on each position information of the journal, the ultrasonic probe receives the ultrasonic signal returned by each spatial position, determines the depth of the ultrasonic probe in the journal according to the ultrasonic signal, and constructs a signal matrix according to the depth. Wherein, each element in the journal position matrix has a mapping relationship with each element in the signal matrix, for example, the journal position matrix is: , and the signal matrix is: , then the signal corresponding to the first spatial position (fx1, fy1, fz1) in the journal position matrix 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 uniquely maps the ultrasonic signal.

[0087] The mapping relationship between the two matrices is established through the journal position matrix and the signal matrix, which provides a prerequisite for subsequent determination and confirmation.

[0088] In step S103, the shape of the defect is determined according to the position information by a tensor quantization method.

[0089] The position information obtained by the ultrasonic probe preliminarily obtains the position information of the defect existing in the shaft neck, and the length of the defect is obtained based on the position information of the defect by a quantification method of a Gyration tensor, which satisfies the following formula:

[0090]

[0091] Wherein, is a tensor, V m is the initial volume of the defect, is the geometric center coordinate of the i-th voxel in the a direction, is the geometric center coordinate of the defect in the a direction, is the geometric center coordinate of the i-th voxel in the β direction, is the geometric center coordinate of the defect in the β direction, and the a direction and the β direction are any two of the x, y, and z directions.

[0092] The tensor of the defect obtained by the above tensor formula is a matrix, and three eigenvalues of the defect tensor are obtained, specifically including R1, R2, and R3. Based on the three eigenvalues, an ellipsoidal sphere is constructed to represent the initial shape of the defect, so that the lengths of the ellipsoidal sphere in three mutually perpendicular directions in space are obtained, and the lengths are obtained in the following manner: 、 and , wherein a is the length of the x-axis direction, b is the length of the y-axis direction, and c is the length of the z-axis direction.

[0093] After determining the length of the defect in space, the shape of the defect needs to be determined according to the elongation index, the flatness index, and the sphericity. The elongation index is used to represent the degree of elongation of the ellipsoidal sphere and the irregular object, the flatness index is used to represent the degree of flatness of the ellipsoidal sphere and the irregular object, and the sphericity represents the degree of approximation of the ellipsoidal sphere to the sphere. After obtaining the lengths in different directions, the elongation index, the flatness index, and the sphericity of the defect are calculated, which satisfy the following formulas:

[0094] Elongation index: EI = b / a, wherein EI is the elongation index, b is the length of the y-axis direction, and a is the length of the x-axis direction. The smaller the elongation index, the more elongated the shape of the defect.

[0095] Flatness index: FI = c / b, wherein FI is the flatness, b is the length of the y-axis direction, and c is the length of the z-axis direction. The smaller the flatness index, the more flat the defect.

[0096] Sphericity: , wherein R i , R j is the eigenvector of the tensor. When S1 is closer to 1, the defect is closer to a sphere.

[0097] 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.

[0098] Based on the tensor quantization method, the shape of the defect in the journal can be preliminarily determined, providing a basis for subsequent defect reconstruction and improving the accuracy of reconstruction.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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 2If the plane coordinate corresponds to the volume pixel, the volume pixel is reserved.

[0104] Based on the reserved volume pixel, an ideal three-dimensional image of the journal is obtained. The ideal three-dimensional image of the journal is the same as the actual journal in the three-dimensional image, and the two are the same in radius, length, and axial direction. Figure 9 The ideal three-dimensional image of the journal is shown according to an exemplary embodiment, as shown in Figure 9 As shown, the ideal three-dimensional image presents a cylinder in space. A journal coordinate system is constructed on the ideal three-dimensional image, with the center of the end face of the journal in the ideal three-dimensional image as the origin, the axial direction of the journal as the x-axis, the y-axis obtained by rotating the x-axis 90° clockwise in the horizontal plane where the x-axis is located, forming an x-y plane, and the direction perpendicular to the x-y plane and upward as the z-axis.

[0105] In the journal coordinate system, continue to refer to step S104, compare the amplitude of each ultrasonic signal in the signal matrix with the preset threshold value, and if the amplitude of the ultrasonic signal is greater than the preset threshold value, determine that the ultrasonic signal is a signal of a defect position. 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. According to the defect shape and the position information determined in the journal position matrix, the spatial position in the ideal three-dimensional image consistent with the position information is determined as the defect position. Since the ideal three-dimensional image of the journal is the same as the actual journal, the defect position in the ideal three-dimensional image is the real defect existing in the actual journal. And according to the defect shape, the position of the defect in the ideal three-dimensional image can be more accurately mapped. Optionally, the preset threshold value is 2R. Figure 10 The schematic diagram of the journal with a defect is shown according to an exemplary embodiment, as shown in Figure 10 As shown, the defect position is displayed in the ideal three-dimensional image of the journal, and the defect position is displayed as a hole.

[0106] By constructing the ideal three-dimensional model of the journal, the journal is visualized, and the position of the defect in the ideal three-dimensional model is determined through the journal position matrix and the signal matrix, so as to realize accurate positioning of the defect of the journal.

[0107] Step S105, traverse each volume pixel in the ideal three-dimensional image, count the number of defect positions, and determine the counted result as the defect volume of the journal.

[0108] The ideal three-dimensional image is composed of a plurality of volume pixels, and the size of the volume pixel will also differ under different resolutions. For example, in high resolution, the size of the volume pixel will be very small, up to sub-millimeter level, thus having high-precision positioning. In low resolution, the size of the volume pixel will be larger. Therefore, based on the known number of pixel volumes, the volume in the ideal three-dimensional image is obtained according to the size of the pixel volume and the number of pixel volumes.

[0109] With reference back to step S105, the volume of the defect is determined according to the number of volume pixels of the defect position by traversing each volume pixel in the ideal three-dimensional image and counting the number of volume pixels of the defect position.

[0110] In one embodiment, the ideal three-dimensional image is composed of 10000 volume pixels, and the size of each volume pixel is 0.1mm*0.1mm*0.1mm. If the number of volume pixels of the defect position in the ideal three-dimensional image is 400, then the volume of the defect is V=400*0.1*0.1*0.1, i.e. V=0.4mm 3 .

[0111] The volume of the defect on the journal can be determined by the method of counting volume pixels, and the further defect content can be determined according to the size of the volume, and the maintenance plan can be formulated.

[0112] In addition, after the defect position is determined in the ideal three-dimensional image according to the mapped position information in step S104, it further includes:

[0113] In the ideal three-dimensional image, the defect position is rendered as a first color by 3D rendering technology, the remaining non-defect positions are rendered as a second color, and the transparency of the remaining non-defect positions is reduced. For example, the defect position is rendered as red, i.e. the color of the voxel region is assigned as (255, 0, 0), the remaining non-defect positions are rendered as blue, i.e. the color of the voxel region is assigned as (0, 0, 255), and the transparency of the non-defect region is reduced, for example, to 50% of the original transparency.

[0114] The defect position and the non-defect position in the ideal three-dimensional model of the journal are clearly distinguished by 3D rendering technology, the defect position and the non-defect position are distinguished by different colors, and the transparency of the non-defect position is reduced, highlighting the defect in the ideal three-dimensional model, which can further distinguish the type and degree of the defect, and then make a reasonable maintenance decision.

[0115] In one embodiment, in the process of constructing the ideal three-dimensional image of the journal, according to the three-dimensional image of the cube, a corresponding matrix of the three-dimensional image is determined, and the voxel value is assigned as 0. In any Z-Y cross section, the volume pixels satisfying the distance from any plane coordinate to the target coordinate less than or equal to the preset distance threshold are retained in the matrix, and the voxel value of the retained volume pixels is assigned as 1, so that the ideal three-dimensional image of the journal can be determined from the three-dimensional image of the cube. After determining the ideal three-dimensional image of the journal, the signal matrix is traversed to determine that the ultrasonic signal in the signal matrix satisfying the amplitude less than or equal to the preset threshold is the defect in the journal. For example, the preset threshold is 2R, and the amplitude of the ultrasonic signal greater than or equal to 2R is determined to be the defect of the journal. According to the mapping relationship between the signal matrix and the journal position matrix, the position of the defect in the journal position matrix is determined, and based on the position of the defect, the voxel value of the corresponding matrix is assigned as 2, so that the position of the defect can be displayed in the ideal three-dimensional image of the journal. By traversing the voxel value of the matrix and counting the number of voxel values of 2, the volume of the defect in the journal is determined according to the final statistical voxel value of 2.

[0116] In summary, the method for detecting the journal defect of the steam turbine rotor provided by the embodiments of the present application can realize 360° scanning of the journal through the journal scanning system, determine the coordinates of each spatial position of the journal in the journal coordinate system, and preliminarily determine each spatial position of the journal. The journal position matrix is constructed according to the determined position, and the signal matrix is constructed according to the ultrasonic signal. The mapping relationship is established between the two matrices. When the defect is determined through the signal matrix, the actual position of the defect is determined through the mapping relationship. According to the actual position, the defect position can be accurately positioned in the ideal three-dimensional image of the journal, and the defect can be color rendered to realize the visualization of the defect and realize the detailed analysis of the defect. The positions of the defects in the ideal three-dimensional image are counted, and the volume of the defect is determined according to the counting result to realize the quantification of the defect in the journal. The position and volume of the defect can be further analyzed, and key data support is provided for the life assessment of the steam turbine rotor and the development of the maintenance plan of the steam turbine rotor.

[0117] In a second aspect, the embodiments of the present application provide a journal defect detection device for a steam turbine rotor. Figure 11 is a block diagram of a journal defect detection device for a steam turbine rotor according to an exemplary embodiment. As shown in Figure 11 the device is applied to a journal scanning system, which includes a circumferential guide rail and an axial guide rail. The circumferential guide rail surrounds the end surface of the journal, and the axial guide rail is parallel to the axial direction of the journal and connected with an ultrasonic probe. The device includes:

[0118] The acquisition position information module is configured to control the ultrasonic probe to move on the axial guide rail, and control the journal to rotate along the circumferential guide rail and scan the journal by the ultrasonic probe to obtain position information of the journal at each position in space when the ultrasonic probe is at any position on the axial guide rail.

[0119] The determination matrix module is configured to construct a journal position matrix according to the position information, and determine a signal matrix according to each received ultrasonic signal, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix.

[0120] The confirmation defect shape module is configured to determine the defect shape according to the position information by a tensor quantization method.

[0121] The determination defect position module is configured to construct an ideal three-dimensional image of the journal based on the size of the journal, obtain position information mapped by the ultrasonic signal if there is an ultrasonic signal with an amplitude greater than a preset threshold in the signal matrix, and determine a defect position in the ideal three-dimensional image according to the mapped position information and the defect shape.

[0122] The determination defect volume module is configured to traverse each volume pixel in the ideal three-dimensional image, count the number of defect positions, and determine the counted result as a defect volume of the journal.

[0123] It should be noted that the steam turbine rotor journal defect detection device provided in the embodiment is used to implement the above-described embodiments, and has been described above. As used above, the terms "module", "unit", "sub-unit", and the like can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the above embodiment is preferably implemented in software, hardware, or a combination of software and hardware can also be implemented and conceived.

[0124] In a third aspect, the embodiments of the present application provide an electronic device, Figure 12 is a block diagram of an electronic device according to an exemplary embodiment. As Figure 12 shown, the electronic device can include a processor 81 and a memory 82 having stored computer program instructions.

[0125] In particular, the above-mentioned processor 81 can include a central processing unit (CPU), or a specific integrated circuit (Application Specific Integrated Circuit, referred to as ASIC), or can be configured to implement one or more integrated circuits of the embodiments of the present application.

[0126] The memory 82 can include a mass storage for data or instructions. By way of example, and without limitation, the memory 82 can include a hard disk drive (HDD), a floppy disk drive, a solid-state drive (SSD), a flash memory, a compact disk read only memory (CD-ROM), a digital versatile disk (DVD), a tape drive, a USB drive, or a combination of two or more of these. Where appropriate, the memory 82 can include removable or non-removable (or fixed) media. Where appropriate, the memory 82 can be internal or external to the data processing apparatus. In certain embodiments, the memory 82 is a nonvolatile memory. In certain embodiments, the memory 82 includes a read only memory (ROM). Where appropriate, this ROM can be mask programmed ROM, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), electrically alterable ROM (EAROM), or flash memory (FLASH) or a combination of two or more of these. Where appropriate, the ROM can include a combination of these without limitation. Where appropriate, the memory 82 includes a random access memory (RAM). Where appropriate, this RAM can be static random access memory (SRAM) or dynamic random access memory (DRAM), which can be Fast Page Mode Dynamic random access memory (FPMDRAM), Extended Data Output Dynamic random access memory (EDODRAM), synchronous dynamic random access memory (SDRAM), or the like.

[0127] The memory 82 can be used to store or buffer various data files required for processing and / or communication, and possible computer program instructions executed by the processor 81.

[0128] The processor 81 reads and executes the computer program instructions stored in the memory 82 to implement the shaft neck defect detection method of the steam turbine rotor in any of the above embodiments.

[0129] In an embodiment, the steam turbine rotor shaft neck defect detection device can further include a communication interface 83 and a bus 80. As shown in the figure, the processor 81, the memory 82, and the communication interface 83 are connected through the bus 80 and complete communication with each other. Figure 12

[0130] The communication interface 83 is used to realize the communication between various modules, devices, units and / or equipment in the embodiments of the present application. The communication interface 83 can also realize data communication with other components, such as external devices, image / data acquisition devices, databases, external storage, and image / data processing workstations, etc.

[0131] ​Bus 80 includes hardware, software, or both, to couple components of the steam turbine rotor journal defect detection apparatus to each other in communication. Although the application is not limited in this regard, bus 80 can include, for example, one or more buses implementing multiple bus formats including data buses of the low pin count (LPC) bus, storage buses of the enhanced industry standard architecture (EISA) bus, memory buses of the accelerated graphics port (AGP) bus and / or peripheral components interconnect (PCI) bus, or wireless buses implementing various of the 802 standards including the wireless application protocol (WAP) and / or the long term evolution (LTE) standard. Bus 80 can include one or more buses, where appropriate. Although the application is not limited in this regard, bus 80 can include one or more buses implementing multiple bus formats. Although the application is not limited in this regard, one or more buses of bus 80 can be used to implement a communication interface 82.

[0132] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, having a program stored thereon, where the program, when executed by a processor, implements the steam turbine rotor journal defect detection method according to the first aspect.

[0133] More particularly, the computer readable storage medium can include, but is not limited to, portable discs, hard disks, random access memories, read-only memories, erasable programmable read-only memories, optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0134] In possible implementation manners, the present application can also be implemented in the form of a program product, which comprises program codes for causing terminal equipment to perform the steps of the method for detecting journal defect of a steam turbine rotor provided by the first aspect when the program product is run on the terminal equipment.

[0135] Wherein, the program codes for executing the present application can be written in any combination of one or more programming languages, which can be executed entirely on the user equipment, partially on the user equipment, as an independent software package, partially on the user equipment and partially on a remote device, or entirely on a remote device.

[0136] The technical features of the above-mentioned embodiments can be combined in any manner. In order to make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described, however, as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present application.

[0137] The above-mentioned embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method of detecting a journal defect of a rotor of a steam turbine, characterized by, The method applies a journal scanning system, the system comprises an ultrasonic probe, a circumferential guide rail and an axial guide rail, the circumferential guide rail is around the outer surface of the journal near the end surface of the journal, the axial guide rail is parallel to the axial direction of the journal and is connected with the ultrasonic probe; the method comprises: controlling the ultrasonic probe to move on the axial guide rail, when the ultrasonic probe is at any position of the axial guide rail, controlling the journal to rotate along the circumferential guide rail and scan the journal by the ultrasonic probe, obtaining the position information of the journal at each position in space; constructing a journal position matrix according to the position information, and determining a signal matrix according to each received ultrasonic signal, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix; determining the defect shape according to the position information by a quantification method of Gyration tensor; based on the size of the journal, constructing an ideal three-dimensional image of the journal, if there is an ultrasonic signal with an amplitude greater than a preset threshold in the signal matrix, obtaining the position information mapped by the ultrasonic signal, determining the defect position in the ideal three-dimensional image according to the mapped position information and the defect shape; traversing each volume pixel in the ideal three-dimensional image, counting the number of defect positions, and determining the defect volume of the journal as the counting result.

2. The method of detecting a journal defect of a steam turbine rotor according to claim 1, characterized by, The system further comprises an axial stepper and a circumferential stepper, and the controlling the ultrasonic probe to move on the axial guide rail, when the ultrasonic probe is at any position of the axial guide rail, controlling the journal to rotate and scan the journal by the ultrasonic probe, obtaining the position information of the journal at each position in space, comprises: A journal coordinate system is constructed, wherein the journal coordinate system takes the center of the journal end face as the origin, takes the journal axial direction as the x axis, and takes the direction from the high-pressure side to the low-pressure side of the steam turbine rotor as the positive direction of the x axis, in the horizontal plane of the x axis, the x axis is rotated clockwise by 90° to determine the y axis and the positive direction of the y axis, and the z axis is determined perpendicularly to the x y plane and in the upward direction; controlling the ultrasonic probe to move on the axial guide rail by the axial stepper based on a first preset step length; determining the horizontal coordinate of each spatial position of the journal according to the position of the ultrasonic probe on the axial guide rail, the first preset step length and the length of the axial guide rail; when the ultrasonic probe is at any position of the axial guide rail, controlling the journal to rotate half a circle in the clockwise direction and the counterclockwise direction respectively from the starting position based on a second preset step length by the circumferential stepper; during the rotation of the journal, scanning the journal by the ultrasonic probe to obtain the detection distance of the journal, and determining the depth coordinate and the longitudinal coordinate of each spatial position of the journal based on the second preset step length and the detection distance; obtaining the position information of the journal at each position in space according to the horizontal coordinate, the longitudinal coordinate and the depth coordinate.

3. The method of claim 2, wherein The method further comprises: based on each position information, the ultrasonic probe receives the ultrasonic signal returned by each spatial position, and determines the depth detected by the ultrasonic probe in the journal according to the ultrasonic signal; constructing a signal matrix according to the depth.

4. The method of claim 1, wherein The method further comprises: based on the end surface radius of the journal and the length of the journal, constructing a three-dimensional image of a cubic body; In the three-dimensional image, a lower left corner behind the cube is taken as an origin, and three mutually perpendicular edges from the origin are taken as an x-axis, a y-axis and a z-axis, thereby constructing a three-dimensional coordinate system, wherein a direction of the x-axis is the same as an axial direction of the journal, the y-axis direction points to a front surface of the cube, the z-axis direction points to an upper surface of the cube, and the cube is located in a first octant of the three-dimensional coordinate system; In the three-dimensional coordinate system, the Z In the Y section, if the distance between any plane coordinate and the target coordinate is less than or equal to the preset distance threshold, 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 of claim 1, wherein, After the defect position is determined in the ideal three-dimensional image according to the mapped position information and the defect shape, the method further comprises: rendering the defect position into a first color by a rendering tool; rendering the rest of the positions in the ideal three-dimensional image into a second color and reducing the transparency of the rest of the positions.

6. A journal scanning system for a steam turbine rotor, the system being used to implement the method of any one of claims 1 to 5 for detecting a journal defect of a steam turbine rotor, the system comprising: Supporting component, guide rail component, ultrasonic probe, stepper; The supporting component comprises a supporting bracket, a supporting base and a limiting piece, the bottom end of the supporting bracket is fixed to the supporting component, and the upper end of the supporting bracket is provided with the limiting piece; The guide rail component comprises an axial guide rail, a first ring guide rail and a second ring guide rail, the first ring guide rail and the second ring guide rail are connected with the limiting piece through a through hole, so that the first ring guide rail and the second ring guide rail are arranged around the outer lateral surface of the journal near the end surface of the journal, and the axial guide rail is arranged between the first ring guide rail and the second ring guide rail and above the surface of the journal; The stepper comprises a ring stepper and an axial stepper, the ring stepper is located in the first ring guide rail, and the axial stepper is connected with the axial guide rail; The ultrasonic probe is connected with 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 value; The system further comprises a processing terminal, which is electrically connected with the ultrasonic probe through a transmission line, so as to transmit the ultrasonic signal detected by the ultrasonic probe to the processing terminal for processing.

7. A device for detecting a journal defect of a rotor of a steam turbine, characterized in that The device applies a journal scanning system, the system comprises a ring guide rail and an axial guide rail, the ring guide rail is arranged around the outer lateral surface of the journal near the end surface of the journal, the axial guide rail is parallel to the axial direction of the journal, and the ultrasonic probe is connected with the axial guide rail; the device comprises: An acquisition position information module is configured to control the ultrasonic probe to move on the axial guide rail, and when the ultrasonic probe is at any position on the axial guide rail, control the journal to rotate along the ring guide rail and scan the journal by the ultrasonic probe, so as to obtain position information of the journal at each position in space; A determination matrix module is configured to construct a journal position matrix according to the position information, and determine a signal matrix according to each received ultrasonic signal, wherein each element in the journal position matrix has a mapping relationship with each element in the signal matrix; A confirmation defect shape module is configured to determine a defect shape according to the position information by a Gyration tensor quantification method. A defect position determining module is configured to construct an ideal three-dimensional image of the journal based on the size of the journal, obtain position information mapped by the ultrasonic signal if the amplitude of the ultrasonic signal in the signal matrix is greater than a preset threshold, and determine a defect position in the ideal three-dimensional image according to the mapped position information and the defect shape. A defect volume determining module is configured to traverse each volume pixel in the ideal three-dimensional image, count the number of defect positions, and determine a defect volume of the journal based on the counted result.

8. An electronic device, comprising: The computer program is stored in the memory and executable on the processor, and the processor executes the computer program to implement the method for detecting a journal defect of a steam turbine rotor according to any one of claims 1 to 5.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the method for detecting a journal defect of a steam turbine rotor according to any one of claims 1 to 5.

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