A turbine blade on-line detection device

Abstract

The present application relates to a kind of steam turbine blade on-line detection device, it includes mounting seat, sliding seat being slidably installed on mounting seat, swing mechanism being installed on the outer side of sliding seat, range finder for emitting ray to steam turbine blade and measuring the range finder being installed on swing mechanism to obtain distance from steam turbine;Range finder moves with swing mechanism in horizontal plane;Sensor assembly is installed on the side wall of sliding seat above swing mechanism;Using the present application, steam turbine main shaft and blade do not need to be disassembled to realize detection, can greatly save dismounting time, steam turbine main shaft also does not need to be hoisted, avoid the damage of main shaft in hoisting process;Effectively improve the detection efficiency of steam turbine blade.There is also the advantages such as accurate detection result, easy operation, wide adaptability.

Description

Technical Field

[0001] This invention relates to an online detection device for steam turbine blades, belonging to the field of steam turbine maintenance technology. Background Technology

[0002] In turbine troubleshooting, blade damage is the leading cause of accidents, and such incidents are the most common type of turbine accident. Common causes of turbine blade failure include fracture and corrosion. However, in some cases, due to the large thermal strain experienced by the turbine, the blades may deform or twist. As turbine blades have been upgraded from traditional straight blades to twisted three-dimensional blades, twisting defects in turbine blades have become increasingly common. The first step in repairing twisted turbine blades is to detect the form and extent of the twist.

[0003] Currently, the inspection methods for steam turbine blades all require disassembling the entire turbine blade assembly, then removing each individual blade and placing it on specialized measuring equipment for testing. Due to the size and weight of the steam turbine, the disassembly process consumes a significant amount of manpower and resources. Furthermore, the turbine blade assembly needs to be removed along with its shaft. After testing, the turbine blades need to be reassembled. If some blades have only minor deformation that cannot be determined visually, each blade must be disassembled and inspected individually. This results in a low efficiency in the turbine inspection process. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an online turbine blade inspection device that avoids disassembling turbine blades, is easy to install and operate, and has high inspection efficiency.

[0005] The present invention adopts the following technical solution:

[0006] The present invention includes a mounting base, a sliding seat slidably mounted on the mounting base, a swing mechanism mounted on the outside of the sliding seat, and a ray rangefinder mounted on the swing mechanism for emitting rays to turbine blades and measuring the distance to the turbine blades; the ray rangefinder moves with the swing mechanism in a horizontal plane; and a sensor assembly is mounted on the side wall of the sliding seat above the swing mechanism.

[0007] The swing mechanism of the present invention includes a sector-shaped frame plate fixedly installed on the outside of the sliding seat, an arc-shaped rack installed on the circumferential wall of the sector-shaped frame plate, a swing shaft rotatably installed at the center of the sector-shaped frame plate, a swing rod horizontally installed on the swing shaft below the sector-shaped frame plate, a stepper motor vertically installed at the end of the swing rod, and a drive gear installed on the drive shaft of the stepper motor, wherein the drive gear meshes with the arc-shaped rack; the ray rangefinder is installed on the top of the swing shaft, and the swing shaft is perpendicular to the main shaft of the steam turbine; the stepper motor drives the drive gear to rotate, the drive gear moves along the arc-shaped rack and drives the swing rod to swing, and the swing rod drives the swing shaft and the ray rangefinder to rotate.

[0008] This invention incorporates a lifting mechanism on a swing mechanism. The swing shaft is a hollow shaft with openings at the top and bottom. The lifting mechanism includes a lead screw, a lead screw motor, a lifting platform, and guide columns. The lower part of the lead screw is spaced through the swing shaft. The lead screw motor is fixedly installed at the top of the swing shaft. The lead screw passes through the lead screw motor and the swing shaft and is connected to the lead screw motor. There are four guide columns, all fixed to a fan-shaped frame plate and symmetrically arranged on both sides of the lead screw motor. Two guide columns are provided on each side of the lead screw motor. The guide holes on the lifting platform are fitted onto the guide columns, and the top of the lead screw rests against the bottom surface of the lifting platform. The X-ray rangefinder is fixedly installed on the top surface of the lifting platform. The lead screw motor drives the lead screw to move up and down. When the lead screw moves upward, it lifts the lifting platform; when it moves downward, it lowers the lifting platform. The lifting platform drives the X-ray rangefinder to move up and down, allowing it to scan turbine blades in different horizontal planes.

[0009] The present invention provides an arc-shaped through groove on the inner side of the arc-shaped wall of the fan-shaped frame plate. The arc-shaped through groove is parallel to the arc-shaped rack. A lifting block is slidably arranged in the arc-shaped through groove, and the bottom of the lifting block is fixed to the top surface of the swing rod.

[0010] The present invention installs a lead screw and nut pair between a mounting base and a sliding base. The lead screw of the lead screw and nut pair is installed on the mounting base, and the nut of the lead screw and nut pair is installed on the sliding base.

[0011] The sensor assembly of the present invention includes a first proximity sensor and a second proximity sensor that are perpendicular to each other; the first proximity sensor is mounted on a sliding seat via an angle plate, the first proximity sensor is parallel to the sliding seat and corresponds to the side of the turbine blade, the second proximity sensor is mounted on the sliding seat and is perpendicular to the turbine main shaft; the second proximity sensor is in the same plane as the turbine main shaft; the second proximity sensor is disposed on one side of the angle plate.

[0012] The present invention has an adapter plate fixedly installed on the outside of the sliding seat, and the swing mechanism and sensor assembly are both installed on the adapter plate.

[0013] The ray rangefinder of this invention is a laser rangefinder or an infrared rangefinder.

[0014] The positive effects of this invention are as follows: When using this invention to detect the degree of twist of a turbine blade, the mounting base of this invention is installed on the lower half of the turbine cylinder. The turbine blade is rotated to bring it close to the X-ray rangefinder. The swing mechanism causes the X-ray rangefinder to swing, thereby measuring the distance values ​​at various points on the turbine blade. These values ​​are then compared with those of normal blades to determine the degree of twist of the turbine blade or to obtain the twisted position of the turbine blade.

[0015] The sliding seat of this invention can slide on the mounting base, thereby driving the swing mechanism and the X-ray rangefinder to slide. During the sliding process, the distance between the rangefinder and the blade can be adjusted, making it easier to find a suitable position to detect the blade and reducing the difficulty of comparison with normal blades.

[0016] By installing the first and second sensors perpendicularly to each other on the mounting base, it can be ensured that the measured blade is always in the same position when measuring different blades. This reduces a lot of workload and saves the overall inspection time for all blades when comparing the measured data with normal blades. The two sensors, which are perpendicularly set, can locate the blade in two dimensions, resulting in higher positioning accuracy.

[0017] The swing mechanism can drive the ray rangefinder to swing or rotate with the swing arm, ensuring the smooth operation of the rangefinder. On the other hand, one end of the swing arm is connected to the swing shaft at the center of the fan-shaped frame plate, and the other end is equipped with a drive gear. The swing amplitude of the swing arm can be precisely controlled by controlling the rotation angle of the drive gear, thus providing a feasible basis for accurately controlling the movement of the rangefinder.

[0018] The suspension slider ensures that the pendulum rod will not shift or twist in the vertical direction, thus ensuring more precise pendulum rod movements and improving detection accuracy.

[0019] The lifting mechanism enables the ray rangefinder to rotate not only in a single plane but also in multiple planes. This allows the ray rangefinder to measure distances at various points on the blade, comprehensively inspect its shape, and obtain 3D data. This provides a more accurate and convenient reference for locating blade twist points and positions. The lifting mechanism not only raises and lowers the ray rangefinder but also ensures that the lead screw running through the swing shaft keeps the lifting platform's point of force on the swing shaft during lifting. This balances the forces received by the lifting platform in both directions, preventing self-locking and resulting in smoother and more stable operation.

[0020] This invention allows for testing without disassembling the turbine main shaft and blades, significantly saving disassembly and assembly time. It also eliminates the need for hoisting the turbine main shaft, preventing damage during hoisting. This effectively improves the testing efficiency of turbine blades. Furthermore, it offers advantages such as accurate test results, convenient operation, and wide applicability. Attached Figure Description

[0021] Appendix Figure 1 This is a schematic diagram of the structure of the present invention;

[0022] Appendix Figure 2 This is a schematic diagram of the swing mechanism and lifting mechanism of the present invention;

[0023] Appendix Figure 3 This is a schematic diagram of the installation position of the swing shaft of the present invention;

[0024] Appendix Figure 4 This is a schematic diagram of the working state structure of the present invention.

[0025] In the attached diagram:

[0026] 1-Steam turbine blade, 2-Mounting base, 3-Sliding seat, 4-Fan-shaped frame plate, 5-First proximity sensor, 6-Second proximity sensor, 7-Arc-shaped rack, 8-Swing rod, 9-Driving gear, 10-Stepper motor, 11-Lifting slider, 12-Arc-shaped through slot, 13-Swing shaft, 14-Lead screw, 15-Lead screw motor, 16-Lifting platform, 17-Ray distance meter, 18-Guide column, 19-Lead screw and nut pair, 20-Lifting mechanism, 21-Angle plate, 22-Adapter plate. Detailed Implementation

[0027] Example 1:

[0028] As attached Figure 1 , 4 As shown, the present invention includes a mounting base 2, a sliding seat 3 slidably mounted on the mounting base 2, a swing mechanism mounted on the outside of the sliding seat 3, and a ray rangefinder 17 mounted on the swing mechanism for emitting rays to the turbine blade 1 and measuring the distance to the turbine blade. The ray rangefinder 17 moves with the swing mechanism in a horizontal plane to detect the turbine blade 1. In this embodiment, the ray rangefinder 17 is a laser rangefinder or an infrared rangefinder. If it is necessary to detect the degree of twist of a certain blade, it is only necessary to install the mounting base 2 on the lower half of the turbine cylinder, rotate the turbine blade 1 to bring it close to the ray rangefinder 17, operate the swing mechanism to make the ray rangefinder 17 swing, measure the distance values ​​at various points on the turbine blade 1, and then compare the values ​​with those of a normal blade to determine the degree of twist of the turbine blade 1, or to obtain the twisted position of the turbine blade 1.

[0029] As attached Figure 1As shown, the present invention installs a lead screw and nut assembly 19 between the mounting base 2 and the sliding base 3. The lead screw of the lead screw and nut assembly 19 is installed on the mounting base 2, and the nut of the lead screw and nut assembly 19 is installed on the sliding base 3. The lead screw and nut assembly 19 causes the sliding base 3 to slide on the mounting base 2.

[0030] As attached Figure 2 , 3 As shown, the swing mechanism of the present invention includes a sector-shaped frame plate 4 fixedly installed on the outside of the sliding seat 3, an arc-shaped rack 7 installed on the circumferential wall of the sector-shaped frame plate 4, a swing shaft 13 rotatably installed at the center of the sector-shaped frame plate 4, a swing rod 8 horizontally installed on the swing shaft 13 below the sector-shaped frame plate 4, a stepper motor 10 installed at the end of the swing rod 8, and a drive gear 9 fixedly installed on the transmission shaft of the stepper motor 10. The drive gear 9 meshes with the arc-shaped rack 7. The X-ray rangefinder 17 is installed on the top of the swing shaft 13, and the swing shaft 13 is perpendicular to the main shaft of the steam turbine. The stepper motor 10 drives the drive gear 9 to rotate, and the drive gear 9 moves along the arc-shaped rack 7 to drive the swing rod 8 to swing. The swing rod 8 drives the swing shaft 13 and the X-ray rangefinder 17 to rotate. The swing mechanism can, on the one hand, drive the X-ray rangefinder 17 to swing with the swing rod 8 to achieve detection; on the other hand, by controlling the stepping of the stepper motor 10 and the rotation angle of the drive gear 9, the swing amplitude of the swing rod 8 is controlled, thereby precisely controlling the movement of the X-ray rangefinder 17.

[0031] As attached Figure 2 As shown, the present invention includes a lifting mechanism 20 on the swing mechanism; the swing shaft 13 is a hollow shaft with openings at the top and bottom; the lifting mechanism 20 includes a lead screw 14, a lead screw motor 15, a lifting platform 16, and a guide column 18; the lower part of the lead screw 14 is disposed through the swing shaft 13 with a gap, and is coaxially disposed with the swing shaft 13; the lead screw motor 15 is fixedly installed at the top of the swing shaft 13, and the lead screw 14 passes through the lead screw motor 15 and the swing shaft 13 and is threadedly connected to the lead screw motor 15; the lifting platform 16 is a rectangular plate.

[0032] Four guide columns 18 are fixed to the fan-shaped frame plate 4 and symmetrically arranged on both sides of the lead screw motor 15. Two guide columns 18 are arranged on each side of the lead screw motor 15. The guide holes on the lifting platform 16 are fitted onto the guide columns 18. The top of the lead screw 14 rests against the bottom surface of the lifting platform 16. The X-ray rangefinder 17 is fixedly installed on the top surface of the lifting platform 16. The lead screw motor 15 drives the lead screw 14 to push the lifting platform 16 upward. When the lead screw 14 moves downward, the lifting platform 16 falls under its own weight. The lifting platform 16 drives the X-ray rangefinder 17 to move up and down, which can scan various parts of the turbine blade 1 in different horizontal planes.

[0033] The lifting mechanism enables the ray rangefinder 17 to be raised and lowered. On the other hand, when the lead screw 14 is raised and lowered, it ensures that the point of force of the lifting platform 16 is on the swing axis, thereby ensuring that the force on the lifting platform 16 in the upper and lower directions is balanced, avoiding jamming of the lifting platform 16 during the raising and lowering process, and making the movement of the lifting platform 16 smoother and more stable.

[0034] Under the action of the lifting mechanism, the ray rangefinder 17 can not only rotate in a single plane, but also rotate in multiple planes by controlling the lifting mechanism. This allows the ray rangefinder 17 to measure the distance at various points on the blade, thereby enabling comprehensive detection of the shape of various parts of the blade and obtaining 3D data of the blade. This provides a more accurate and convenient reference for finding the twist points and twist positions of the blade.

[0035] As attached Figure 1 As shown, the present invention provides a sensor assembly on the sliding seat 3, the sensor assembly including a first proximity sensor 5 and a second proximity sensor 6 perpendicular to each other; the first proximity sensor 5 is mounted on the sliding seat 3 via a corner plate 21, the first proximity sensor 5 is parallel to the sliding seat 3 and corresponds to the side of the turbine blade 1, the second proximity sensor 6 is mounted on the sliding seat 3 perpendicular to the turbine main shaft; the second proximity sensor 6 is in the same plane as the turbine main shaft; the second proximity sensor 6 is located on one side of the corner plate 21.

[0036] In this embodiment, the stepper motor 10, the lead screw motor 15, and the lead screw nut assembly 19 are all electrically connected to the control module. The control module controls the rotation of the stepper motor 10, the lead screw motor 15, and the lead screw nut assembly 19. The first proximity sensor 5, the second proximity sensor 6, and the ray rangefinder 17 are electrically connected to the data acquisition module. The data acquisition module collects the data sent by the first proximity sensor 5, the second proximity sensor 6, and the ray rangefinder 17. The data acquisition module is electrically connected to the control module and to the wireless transceiver module. The wireless transceiver module sends the data collected by the data acquisition module to the terminal. The specific forms of the control module, the data acquisition module, and the wireless transceiver module are commonly found in ordinary PLC boards and will not be described in detail here.

[0037] Example 2

[0038] This embodiment is a further improvement based on Embodiment 1, as shown in the appendix. Figure 2 As shown, the present invention provides an arc-shaped through groove 12 on the inner side of the arc-shaped wall of the fan-shaped frame plate 4. The arc-shaped through groove 12 is parallel to the arc-shaped rack 7. A lifting slider 11 is slidably disposed within the arc-shaped through groove 12, and the bottom of the lifting slider 11 is fixed to the top surface of the swing rod 8. The lifting slider 11 ensures that the swing rod will not be displaced or twisted in the vertical direction, thereby ensuring that the movement of the swing rod 8 is more precise and improving the accuracy of detection.

[0039] When using this invention, the system first determines whether the turbine blade 1 has reached the designated position based on the information received by the data acquisition module from the first proximity sensor 5 and the second proximity sensor 6. If it has not reached the designated position, the turbine blade 1 is moved to the designated position by rotating the turbine main shaft and adjusting the position of the sliding block 3. When the first proximity sensor 5 and the second proximity sensor 6 send electrical signals, it is known that the turbine blade 1 has reached the designated position. Then, the stepper motor 10 is controlled to move. Each time the stepper motor 10 moves, the distance is measured once using the ray rangefinder 17 to obtain a distance value. The data acquisition module packages the rotation data of the stepper motor 10, the rotation data of the lead screw motor 15, and the distance information fed back by the ray rangefinder 17 and sends them to other terminals, such as mobile phones and computers, through the wireless transceiver module. After the stepper motor 10 completes one round of measurement, it is controlled to return to the initial position. Then, the lead screw motor 15 is controlled to move, raising the ray rangefinder 17 to a certain height. The above process is repeated until the position information of the turbine blade 1 at all heights is obtained. After receiving the data packets, other terminals parse them. Once all the measurement data packets are received, a 3D model of the blade can be generated. This model is then compared with that of a normal turbine blade 1 to determine the deformation location and amount of deformation. Alternatively, the information in each data packet can be manually compared with the distance information of a normal turbine blade 1 to determine the deformation location and amount of deformation.

[0040] This invention allows for testing without disassembling the turbine main shaft and blades, significantly saving disassembly and assembly time. It also eliminates the need for hoisting the turbine main shaft, preventing damage during hoisting. This effectively improves the testing efficiency of turbine blades. Furthermore, it offers advantages such as accurate test results, convenient operation, and wide applicability.

[0041] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An online inspection device for steam turbine blades, characterized in that, It includes a mounting base (2), a sliding seat (3) slidably mounted on the mounting base (2), a swing mechanism mounted on the outside of the sliding seat (3), and a ray rangefinder (17) mounted on the swing mechanism for emitting rays to the turbine blades (1) and measuring the distance to the turbine blades; the mounting base (2) is mounted on the lower half of the turbine cylinder, and the ray rangefinder (17) moves with the swing mechanism in the horizontal plane; A sensor assembly is mounted on the side wall of the sliding seat (3) above the swing mechanism; The swing mechanism includes a fan-shaped frame plate (4) fixedly installed on the outside of the sliding seat (3), an arc-shaped rack (7) installed on the circumferential wall of the fan-shaped frame plate (4), a swing shaft (13) rotatably installed at the center of the fan-shaped frame plate (4), a swing rod (8) horizontally installed on the swing shaft (13) below the fan-shaped frame plate (4), a stepper motor (10) vertically installed at the end of the swing rod (8), and a drive gear (9) installed on the transmission shaft of the stepper motor (10), wherein the drive gear (9) meshes with the arc-shaped rack (7); The ray rangefinder (17) is mounted on top of the swing shaft (13), which is perpendicular to the main shaft of the steam turbine; The stepper motor (10) drives the drive gear (9) to rotate. The drive gear (9) moves along the arc rack (7) and drives the swing arm (8) to swing. The swing arm (8) drives the swing shaft (13) and the ray rangefinder (17) to rotate. The sensor assembly includes a first proximity sensor (5) and a second proximity sensor (6) that are perpendicular to each other; the first proximity sensor (5) is mounted on a sliding seat (3) via a corner plate (21), the first proximity sensor (5) is parallel to the sliding seat (3) and corresponds to the side of the turbine blade (1), the second proximity sensor (6) is mounted on the sliding seat (3) and is perpendicular to the turbine main shaft; the second proximity sensor (6) is in the same plane as the turbine main shaft; the second proximity sensor (6) is located on one side of the corner plate (21); Based on the information received by the data acquisition module from the first proximity sensor (5) and the second proximity sensor (6), it is determined whether the turbine blade (1) has reached the designated position; A lifting mechanism (20) is provided on the swing mechanism, and the swing shaft (13) is a hollow shaft with openings at the top and bottom; The lifting mechanism (20) includes a lead screw (14), a lead screw motor (15), a lifting platform (16), and a guide column (18); the lower part of the lead screw (14) is inserted through the swing shaft (13) with a gap, the lead screw motor (15) is fixedly installed at the top of the swing shaft (13), and the lead screw (14) passes through the lead screw motor (15) and the swing shaft (13) and is connected to the lead screw motor (15); There are four guide columns (18), all fixed to the fan-shaped frame plate (4) and symmetrically arranged on both sides of the screw motor (15). Two guide columns (18) are set on each side of the screw motor (15). The guide hole on the lifting platform (16) is fitted onto the guide column (18). The top of the screw (14) abuts against the bottom surface of the lifting platform (16). The ray rangefinder (17) is fixedly installed on the top surface of the lifting platform (16). The screw motor (15) drives the screw (14) to move up and down. The screw (14) pushes the lifting platform (16) up and down. The screw (14) moves down to make the lifting platform (16) fall. The lifting platform (16) drives the ray rangefinder (17) to move up and down to scan the turbine blades (1) in different horizontal planes.

2. The online inspection device for steam turbine blades according to claim 1, characterized in that, An arc-shaped through groove (12) is provided on the inner side of the arc-shaped wall of the fan-shaped frame plate (4). The arc-shaped through groove (12) is parallel to the arc-shaped rack (7). A lifting block (11) is slidably provided in the arc-shaped through groove (12). The bottom of the lifting block (11) is fixed to the top surface of the swing rod (8).

3. The online inspection device for steam turbine blades according to claim 1, characterized in that, A lead screw and nut assembly (19) is installed between the mounting base (2) and the sliding base (3). The lead screw of the lead screw and nut assembly (19) is installed on the mounting base (2), and the nut of the lead screw and nut assembly (19) is installed on the sliding base (3).

4. The online inspection device for steam turbine blades according to claim 1, characterized in that, An adapter plate (22) is fixedly installed on the outside of the sliding seat (3), and the swing mechanism and sensor assembly are both installed on the adapter plate (22).

5. The online inspection device for steam turbine blades according to claim 1, characterized in that, The ray rangefinder (17) is a laser rangefinder or an infrared rangefinder.

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