Intelligent measurement method and device for super-large components of steam turbine

Abstract

The application relates to an intelligent measurement method and a measurement device for a super-large component of a steam turbine, and belongs to the field of steam turbine detection. The measurement method comprises the following steps: under the condition that a steam cylinder of a steam turbine is combined, a high-precision laser radar is installed on a moving long shaft, the moving long shaft penetrates through the steam cylinder, a plurality of tool balls are arranged and fixed at one end or both ends of the steam cylinder, before measurement, the laser radar scans all the tool balls, a global coordinate system is established, the laser radar calibrates the starting position of the steam cylinder, the laser radar can scan internal point cloud data of the steam cylinder by controlling the moving distance, the laser radar automatically scans all the tool balls once the position is moved, and the coordinate system is aligned with the first coordinate system, the point cloud is ensured to be in the same coordinate system, the obtained point cloud data is processed through a software algorithm, and high-precision dimensions in the steam cylinder can be obtained. The application eliminates safety hazards, greatly reduces the workload, improves the work efficiency, greatly improves the measurement precision, and reduces the measurement error.

Description

Technical Field

[0001] This invention relates to an intelligent measurement method and device for ultra-large components of steam turbines, belonging to the field of steam turbine testing. Background Technology

[0002] The turbine cylinder adopts a horizontal split-plane structure, consisting of an upper cylinder (upper cylinder / cylinder head) and a lower cylinder (lower cylinder). Flanges and high-strength fastening bolts are arranged on the split plane, forming a sealed steam chamber after assembly to house the rotor, diaphragms, steam seals, and other flow-passing components. The overall component is large in size, with a large radial depth and limited internal operating space. When the equipment is in cylinder-closed operation, the traditional industry measurement method is rotor-drop measurement. This method closely reflects the actual operating condition, as the upper and lower cylinders are fully engaged and bolts are tightened, completely replicating the cylinder's self-weight sag, inner cylinder support deformation, and rotor self-weight deflection. Compared to methods like dummy shaft or half-cylinder measurements, the data is closest to the actual clearance during hot operation of the unit, making it the legally mandated benchmark method for power plant installation, overhaul, and acceptance. However, this method also has significant drawbacks: not only are the measurement values ​​largely inaccurate, but the operation also requires repeated rotor hoisting, resulting in a huge workload and high safety risks; the measurement errors have multiple sources, leading to poor stability and requiring multiple adjustments to the dimensions. In summary, the overall process of measuring the rotor is cumbersome and complex, the work efficiency is low, and the measurement accuracy cannot meet the requirements. Summary of the Invention

[0003] The present invention aims to provide an intelligent measurement method for ultra-large components of steam turbines, so as to solve the detection problems existing in the current measurement of rotors.

[0004] The technical solution adopted in this invention is as follows: An intelligent measurement method for ultra-large components of steam turbines includes the following steps: S1. Before the upper and lower cylinders of the steam turbine are closed, a movable long shaft is installed axially between the upper and lower cylinders. A laser radar with horizontal rotation and pitch rotation functions is movably installed on the movable long shaft. The laser radar and its drive mechanism are electrically connected to the control module. S2. After the lidar is installed, the upper and lower cylinders of the steam turbine are closed; S3. Multiple tool balls are fixedly arranged at one or both ends of the cylinder, and the arrangement of all tool balls meets the spatial position requirements of not being at the same height and not being on the same plane; S4. Input the distance to be scanned of the cylinder into the control module. The control module controls the lidar to automatically scan all tool balls first, establish a global coordinate system through the algorithm, and calibrate the starting position of the cylinder at the same time. S5. The control module controls the lidar to move to the scanning position and rescans all tool spheres, ensuring they are in a unified coordinate system through an algorithm. S6. The lidar begins scanning, scanning the four quadrants (upper, lower, left, and right) of each position radially, collecting point cloud data of the circumference of each scanning position, or, as needed, subdividing the circumference into more scanning areas to obtain continuous point cloud information of the circumference at a specified position under cylinder closing conditions. S7. The current position scan ends, and the machine automatically moves to the next position, then repeats steps S5~S6; S8. Once all designated position information has been scanned, information acquisition under cylinder engagement state is complete; S9. The control module calculates the cylinder size in the closed state based on the collected information, realizing high-precision measurement of the dimensions of ultra-large components of the steam turbine.

[0005] Furthermore, in step S1, when the blind zone distance of the lidar is less than or equal to the cylinder inner diameter radius, the lidar scanning center coincides with the cylinder axis, the lidar is installed horizontally or tilted upwards along the axial direction, or the lidar is installed along the radial plane of the turbine cylinder body and at an angle of 25~60° to the horizontal plane.

[0006] Furthermore, in step S1, when the blind zone distance of the lidar is greater than the inner diameter radius of the cylinder, the position of the moving long axis is deviated from the turbine shaft center, so that the lidar is installed off the turbine shaft center, ensuring that the effective scanning distance of the lidar is greater than the inner diameter radius of the cylinder; otherwise, there will be no data in the blind zone.

[0007] Furthermore, the tool ball in step S3 is a standard matte ball or a reflective ball.

[0008] Furthermore, in steps S4 and S5, the algorithm is implemented by combining a three-dimensional seven-parameter Bursa coordinate transformation model, least squares global adjustment, and automatic target center identification.

[0009] This invention also provides a measuring device for realizing the intelligent measurement method for the aforementioned large components of a steam turbine. It includes the upper and lower cylinders of the steam turbine, a lidar unit, a control module, a moving long shaft, a tool ball mounting bracket, and multiple tool balls. The movable long shaft is fixedly installed between the upper and lower cylinders of the steam turbine. A rack is mounted axially on the movable long shaft. The lidar is mounted on a radar base. A drive motor is installed below the radar base. A gear is mounted on the shaft of the drive motor that meshes with the rack. When the drive motor operates, the radar base and the lidar move together along the length of the rack. The tool balls are arranged at one or both ends of the cylinder, and all tool balls are mounted on the tool ball mounting bracket. The arrangement of the tool balls meets the spatial position requirements of not being at the same height and not on the same plane. The control module is electrically connected to the lidar and the drive motor respectively.

[0010] Furthermore, the tool sphere is a standard matte sphere or a reflective sphere.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves automated measurement. By automatically controlling the lidar to move along a long axis, it can radially scan the four quadrants (upper, lower, left, and right) of each position when the cylinder is engaged, obtaining high-precision data. The circumference of the scanned position can be subdivided into more scanning areas as needed to acquire continuous point cloud information of a specified position when the cylinder is engaged, further improving measurement accuracy. Compared to traditional measurement methods, it eliminates safety hazards, significantly reduces workload, and improves work efficiency. It also greatly improves measurement accuracy and reduces measurement errors. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the measuring device for the intelligent measurement method of ultra-large components of steam turbines according to the present invention; Figure 2 for Figure 1 A partial structural diagram of a lidar unit mounted on a moving long axis; Figure 3 This is a schematic diagram showing the position of the moving long shaft of the steam turbine when the upper and lower cylinders are in the closed state. Figure 4 This is a schematic diagram illustrating the application of Embodiment 1 of the present invention; Figure 5 This is a schematic diagram illustrating the application of Embodiment 2 of the present invention; Figure 6 This is a control principle diagram of the measuring device for the intelligent measurement method of ultra-large components of steam turbines according to the present invention. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The objectives, technical solutions, and advantages of the present invention will become clearer from the following description. It should be noted that the described embodiments are preferred embodiments of the present invention, but not all embodiments.

[0015] Combination Figures 1 to 3 As shown, an intelligent measurement method for ultra-large components of steam turbines includes the following steps: S1. After the lower cylinder of the steam turbine is installed, before the upper and lower cylinders are joined, a long metal movable shaft is installed axially between the upper and lower cylinders. A laser radar with horizontal rotation and pitch rotation functions is movably mounted on the long movable shaft. The laser radar and its drive mechanism are electrically connected to the control module (see reference). Figure 6 ); S2. After the lidar is installed, the upper and lower cylinders of the steam turbine are closed; S3. Multiple tool balls are fixedly arranged at one or both ends of the cylinder. The arrangement of all tool balls meets the spatial position requirements of not being at the same height and not on the same plane. The tool balls are standard matte balls or reflective balls. S4. Input the distance to be scanned of the cylinder into the control module. The control module controls the lidar to automatically scan all tool balls first, establish a global coordinate system through the algorithm, and calibrate the starting position of the cylinder at the same time. S5. The control module controls the lidar to move to the scanning position and rescans all tool spheres, ensuring they are in a unified coordinate system through an algorithm. In steps S4 and S5, the algorithm is implemented by combining a three-dimensional seven-parameter Bursa coordinate transformation model, least squares global adjustment, and automatic target center identification.

[0016] S6. The lidar begins scanning, scanning the four quadrants (upper, lower, left, and right) of each position radially, collecting point cloud data of the circumference of each scanning position, or, as needed, subdividing the circumference into more scanning areas to obtain continuous point cloud information of the circumference at a specified position under cylinder closing conditions. S7. The current position scan ends, and the machine automatically moves to the next position, then repeats steps S5~S6; S8 completes information acquisition in the cylinder-closed state after scanning all designated position information; S9. The control module calculates the cylinder size in the closed state based on the collected information, realizing high-precision measurement of the dimensions of ultra-large components of the steam turbine.

[0017] Example 1

[0018] refer to Figure 4 For cylinders where the radius of the cylinder bore is greater than the blind zone distance of the lidar, and the blind zone distance of the lidar is less than the radius of the cylinder bore, the lidar scanning center coincides with the cylinder axis, the moving long axis is parallel to the cylinder center, and the lidar is installed horizontally or tilted upwards along the axial direction. The lidar is installed along the radial plane of the turbine cylinder body and at an angle of 25-60° to the horizontal plane. Data is collected by controlling the lidar to be moved to each stage stator vane or between stages.

[0019] Example 2

[0020] For cylinders where the radius of the inner bore is smaller than the blind zone distance of the lidar, the lidar's blind zone distance is larger than the cylinder's inner bore radius. If the lidar is installed on the cylinder block axis, no data can be collected. Therefore, the position of the moving long axis is offset from the turbine's axis, allowing the lidar to be installed off-center from the turbine's axis. The lidar position can be offset to the left, right, top, or bottom. The installation position must ensure that the lidar's effective scanning distance is greater than the cylinder's inner bore radius; otherwise, no data will be collected within the blind zone. Figure 5 In this system, the lidar's scanning range is 70 degrees. There are two 70-degree zones, one above and one below; data collected within this range can be used to fit the diameter. The lidar is controlled to move to each stage of still blades or between stages to scan and collect data.

[0021] This invention also provides a measuring device for realizing an intelligent measurement method for ultra-large components of steam turbines, and continues to refer to... Figure 1-3 It includes the upper and lower cylinders 1b of the steam turbine 1, the lidar 2, the control module 3, the moving long shaft 4, the tool ball mounting bracket 5, and multiple tool balls 6.

[0022] The movable long shaft 4 is fixedly installed between the upper and lower cylinders of the steam turbine. A rack 7 is mounted axially on the movable long shaft. The lidar 2 is mounted on a radar base 2a, with both sides of the radar base 2a contacting the upper surface of the movable long shaft 4. A drive motor 8 is installed below the radar base 2a. A gear 9 is mounted on the shaft of the drive motor 8, meshing with the rack 7. When the drive motor 8 operates, the radar base 2a and the lidar 2 move together along the length of the rack 7, and the radar base 2a slides relative to the movable long shaft. The movement of the lidar is not limited to a rack and pinion mechanism; other transmission methods, such as synchronous belts or ball screws, can also be used.

[0023] The tool balls 6 are arranged at one or both ends of the cylinder, and all tool balls are mounted on the tool ball mounting frame 5. The arrangement of the tool balls meets the spatial requirements of not being at the same height and not on the same plane. The tool balls can also be fixed independently of the bracket, without the need for a bracket. The tool balls are arranged as widely as possible to ensure that the radar can scan and cover the cylinder even when it moves. The control module 3 is electrically connected to the lidar 2 and the drive motor 8 respectively.

[0024] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Obviously, any person skilled in the art can easily conceive of substitutions or variations based on the above embodiments to obtain other embodiments, and these should all be covered within the scope of protection of the present invention.

Claims

1. An intelligent measurement method for ultra-large components of steam turbines, characterized in that, Includes the following steps: S1. Before the upper and lower cylinders of the steam turbine are closed, a movable long shaft is installed axially between the upper and lower cylinders. A laser radar with horizontal rotation and pitch rotation functions is movably installed on the movable long shaft. The laser radar and its drive mechanism are electrically connected to the control module. S2. After the lidar is installed, the upper and lower cylinders of the steam turbine are closed; S3. Multiple tool balls are fixedly arranged at one or both ends of the cylinder, and the arrangement of all tool balls meets the spatial position requirements of not being at the same height and not being on the same plane; S4. Input the distance to be scanned of the cylinder into the control module. The control module controls the lidar to automatically scan all tool balls first, establish a global coordinate system through the algorithm, and calibrate the starting position of the cylinder at the same time. S5. The control module controls the lidar to move to the scanning position and rescans all tool spheres, ensuring they are in a unified coordinate system through an algorithm. S6. The lidar begins scanning, scanning the four quadrants (upper, lower, left, and right) of each position radially, collecting point cloud data of the circumference of each scanning position, or, as needed, subdividing the circumference into more scanning areas to obtain continuous point cloud information of the circumference at a specified position under cylinder closing conditions. S7. The current position scan ends, and the machine automatically moves to the next position, then repeats steps S5~S6; S8 completes information acquisition in the cylinder-closed state after scanning all designated position information; S9. The control module calculates the cylinder size in the closed state based on the collected information, realizing high-precision measurement of the dimensions of ultra-large components of the steam turbine.

2. The intelligent measurement method for ultra-large components of steam turbines according to claim 1, characterized in that: In step S1, when the blind zone distance of the lidar is less than or equal to the inner diameter radius of the cylinder, the scanning center of the lidar coincides with the cylinder axis, and the lidar is installed horizontally along the axial direction or tilted upwards, or the lidar is installed along the radial plane of the turbine cylinder body and at an angle of 25 to 60 degrees to the horizontal plane.

3. The intelligent measurement method for ultra-large components of steam turbines according to claim 1, characterized in that: In step S1, when the blind zone distance of the lidar is greater than the inner diameter radius of the cylinder, the position of the moving long axis is deviated from the axis of the turbine, so that the lidar is installed away from the axis of the turbine, ensuring that the effective scanning distance of the lidar is greater than the inner diameter radius of the cylinder; otherwise, there will be no data in the blind zone.

4. The intelligent measurement method for ultra-large components of steam turbines according to claim 1, characterized in that: The tool ball in step S3 is a standard matte ball or a reflective ball.

5. The intelligent measurement method for ultra-large components of steam turbines according to claim 1, characterized in that: In steps S4 and S5, the algorithm is implemented by combining a three-dimensional seven-parameter Bursa coordinate transformation model, least squares global adjustment, and automatic target center identification.

6. A measuring device for implementing the intelligent measurement method for ultra-large components of a steam turbine as described in claim 1, characterized in that: It includes the upper and lower cylinders of the steam turbine, lidar, control module, and moving long shaft. Tool ball mounting bracket and multiple tool balls, The movable long shaft is fixedly installed between the upper and lower cylinders of the steam turbine. A rack is mounted axially on the movable long shaft. The lidar is mounted on a radar base. A drive motor is installed below the radar base. A gear is mounted on the shaft of the drive motor that meshes with the rack. When the drive motor operates, the radar base and the lidar move together along the length of the rack. The tool balls are arranged at one or both ends of the cylinder. All tool balls are mounted on tool ball mounting brackets, which serve only as supports and fixations. The brackets can be placed vertically or horizontally. The arrangement of the tool balls conforms to the spatial requirements of not being at the same height and not on the same plane. The control module is electrically connected to the lidar and the drive motor, respectively.

7. The measuring device according to claim 6, characterized in that: The tool sphere is either a standard matte sphere or a reflective sphere.

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