Looseness monitoring device for fan tower drum flange joint

Abstract

The invention relates to the technical field of fan tower cylinders, in particular to a fan tower cylinder flange joint looseness monitoring device. The device comprises a foundation, a lower tower drum and an upper tower drum, a flange plate and a connecting base plate are arranged between the lower tower drum and the upper tower drum; a ball cavity is formed in the connecting base plate, a ball is arranged in the ball cavity, the ball cavity is communicated with a first mounting hole and a second mounting hole, an axial sensor is arranged in the first mounting hole, and a radial sensor is arranged in the second mounting hole; in a normal state, the spring is extruded to be in a compressed state, stable elastic force is applied to the pressing plate to enable the pressure sensor to monitor reference pressure, when bolts between flange plates are loosened and separated, the pressure between the two sets of connecting base plates is reduced, the spring can release the elastic force, and then the pressing plate moves; at the moment, the reference pressure monitored by the pressure sensor changes, whether the pre-tightening force of the bolt is loosened or not is reflected, and key data are provided for loosening early warning.

Description

Technical Field

[0001] This invention relates to the field of wind turbine tower technology, and more specifically, to a device for monitoring loosening of the flange connection of a wind turbine tower. Background Technology

[0002] With the rapid development of wind power generation, onshore medium and high wind speed areas have been almost fully developed. However, the central, eastern, and southern regions of my country have abundant low wind speed (4.5 m / s to 6.5 m / s) resources, with a exploitable capacity of 1 billion kWh. These resources are close to the grid load center and have huge development potential. However, wind turbines in low wind speed areas require taller towers to capture higher wind speeds and increase power generation. This has forced the construction of wind turbine towers in low wind speed areas to continuously increase, with tower heights in the central, eastern, and southern regions of China already reaching the 160m level.

[0003] Existing towers are exposed to the natural environment for a long time, especially under harsh conditions such as humidity and salt spray. The steel surface is prone to corrosion, which reduces the thickness of the tower wall and reduces its load-bearing capacity. Furthermore, due to the height of the tower body, the higher the wind turbine, the easier it is to capture high-speed winds, which leads to a decrease in the stability of the tower and poses a huge safety hazard. Summary of the Invention

[0004] In view of the above-mentioned problems in the existing technology, the purpose of the present invention is to provide a monitoring device for loosening of the flange connection of wind turbine tower.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A device for monitoring loosening of flange connection of wind turbine tower, the device includes a foundation, a lower tower is provided on the foundation, and an upper tower is provided on the top of the lower tower. A set of flanges is provided at the top of the lower tower and at the bottom of the upper tower. A connecting gasket is provided on the opposite side of each of the two sets of flanges. The connecting gaskets in the same set are fixedly connected to the flanges by bolts and nuts. A data acquisition device is also provided on the inner wall of the lower tower. A ball bearing cavity is symmetrically arranged on both sides of the bolt inside the connecting pad. A ball bearing is provided in the ball bearing cavity. The ball bearing cavity is connected to a first mounting hole and a second mounting hole inside the connecting pad. The first mounting hole faces the axis of the lower tower and the upper tower. The second mounting hole faces the side of the connecting pad and is perpendicular to the direction of the first mounting hole. An axial sensor is provided in the first mounting hole and a radial sensor is provided in the second mounting hole. The ball bearing can contact the axial sensor and the radial sensor.

[0007] Furthermore, the vertical cross-section of the connecting gasket is "L" shaped, and the two inner sides of the connecting gasket partially cover the top and inner sides of the flange, respectively. The two sets of connecting gaskets together form a "C" shape. The connecting pad is also provided with vertical connecting grooves symmetrically arranged on both sides of the bolt. Springs are provided in the upper and lower sets of connecting grooves located at the same horizontal position. Pressure plates that can slide inside the connecting grooves are provided at the upper and lower ends of the springs.

[0008] Furthermore, a pressure sensor is provided in the connecting groove to contact the pressure plate, and the pressure sensor is also located on the other side of the corresponding pressure plate opposite to the spring.

[0009] Furthermore, the pressure sensor, the axial sensor, and the radial sensor are all electrically connected to the data acquisition unit via wires. The data acquisition unit has a built-in wireless transmission module and is connected to a remote monitoring terminal.

[0010] Furthermore, the connecting pad has symmetrical threading holes on its left and right sides and inner side, respectively, relative to the bolt. The two threading holes on the same side are connected by the first mounting hole, the ball bearing cavity and the second mounting hole. The threading holes are provided with waterproof connectors at their ends.

[0011] Furthermore, the ball bearing cavity is a hemispherical groove, and the ball bearing protrudes from the connecting pad and contacts the flange.

[0012] Furthermore, the monitoring ends of both the axial sensor and the radial sensor are arc-shaped and in contact with the ball bearing.

[0013] Furthermore, the detection end of the axial sensor is oriented towards the central axis of the lower tower and the upper tower, and the monitoring end of the radial sensor is perpendicular to the detection end of the axial sensor.

[0014] Furthermore, several sets of reinforcing rods are equidistantly distributed between the foundation and the lower tower.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention utilizes two sets of connecting pads and the coordinated use of a spring, pressure plate, and pressure sensor between them. Under normal conditions, the spring is compressed by the two sets of connecting pads and applies a stable elastic force to the pressure plate, allowing the pressure sensor to monitor the reference pressure. When the bolts and nuts between the two flanges loosen and separate, the pressure between the two sets of connecting pads decreases, the spring releases its elastic force, and the pressure plate moves. At this time, the reference pressure monitored by the pressure sensor changes, thus reflecting whether the preload of the bolts has loosened, providing key data for loosening early warning.

[0016] 2. This invention utilizes the combined use of axial and radial sensors and ball bearings. When the two sets of flanges separate, the ball bearings will displace inside the ball bearing cavity. At this time, the monitoring end of the axial sensor will detect the change in axial force transmitted by the ball bearings, thereby determining the tilt direction of the wind turbine tower. Meanwhile, the radial sensor will detect the change in radial force transmitted by the ball bearings, i.e., the change in the vertical direction, thereby monitoring the loosening between the two sets of flanges and improving the accuracy and reliability of the monitoring data. Attached Figure Description

[0017] Figure 1 This is a front view of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the overall structure of the present invention; Figure 3 This is a partial structural front view of the present invention; Figure 4 This is a cross-sectional view of the connecting pad structure of the present invention; Figure 5 This is a cross-sectional view of the internal structure of the connecting groove of the present invention; Figure 6 This is a cross-sectional view of the radial sensor structure of the present invention; Figure 7 This is a partial structural cross-sectional view of the present invention; Figure 8 For the present invention Figure 4 Schematic diagram of the structure at point A; Figure 9 For the present invention Figure 5 Schematic diagram of the structure at point B.

[0018] Reference numerals: 1. Foundation; 101. Reinforcing rod; 2. Lower tower; 3. Upper tower; 4. Flange; 401. Bolt; 402. Nut; 5. Connecting pad; 501. Connecting groove; 502. Spring; 503. Pressure plate; 504. Pressure sensor; 6. Ball bearing cavity; 601. Ball bearing; 7. First mounting hole; 701. Axial sensor; 8. Second mounting hole; 801. Radial sensor; 9. Wiring hole; 901. Waterproof connector; 10. Data acquisition unit. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments.

[0020] like Figures 1 to 9 As shown, the wind turbine tower flange connection loosening monitoring device of the present invention includes a foundation 1, a lower tower 2 provided on the foundation 1, and an upper tower 3 provided on the top of the lower tower 2.

[0021] A set of flanges 4 is provided at the top of the lower tower 2 and the bottom of the upper tower 3, thus forming two sets of flanges 4. A connecting gasket 5 is provided on each of the two sets of flanges 4 on opposite sides. The vertical cross section of the connecting gasket 5 is "L" shaped, that is, the two inner sides of the connecting gasket 5 partially cover the top and inner sides of the flange 4 respectively.

[0022] The flange 4 and the connecting gasket 5 are fixedly connected by bolts 401 and nuts 402. Bolts 401 and nuts 402 are located in the middle of the connecting gasket 5, and the upper and lower bolts 401 fix the connecting gasket 5 and the flange 4 from the top and bottom surfaces of the connecting gasket 5, respectively.

[0023] A data acquisition device 10 is also installed on the inner wall of the lower tower 2 to complete the overall data acquisition and transmission.

[0024] Inside the connecting pad 5, there are ball bearing cavities 6 symmetrically arranged on both sides of the bolt 401. The ball bearing cavity 6 is a hemispherical groove. A ball bearing 601 is provided in the ball bearing cavity 6. The ball bearing 601 protrudes from the connecting pad 5 and contacts the flange 4.

[0025] The ball bearing cavity 6 is connected to the first mounting hole 7 and the second mounting hole 8 inside the connecting pad 5. An axial sensor 701 is provided in the first mounting hole 7, and a radial sensor 801 is provided in the second mounting hole 8. The axial sensor 701 is oriented in the same direction as the first mounting hole 7, and is set towards the axis of the lower tower 2 and the upper tower 3. The second mounting hole 8 and the radial sensor 801 are oriented in the same direction, and are set perpendicular to the first mounting hole 7 on the same side.

[0026] Under normal conditions, the upper and lower flanges 4 are fixed by bolts 401 and nuts 402. The ball bearing 601 is clamped between the connecting pad 5 and the flange 4 and is subjected to pressure in the vertical direction. At this time, the outer surface of the ball bearing 601 is in slight contact with the detection ends of the axial sensor 701 and the radial sensor 801, respectively. If the bolts 401 loosen and cause the flange 4 to separate, the upper flange 4 will drive the upper connecting pad 5 to move upward, while the lower flange 4 will drive the lower connecting pad 5 to move downward. As a result, the ball bearing 601 will move inside the ball bearing cavity 6. At this time, the axial sensor 701 and the radial sensor 801 will respectively detect the displacement change of the ball bearing 601, thereby reflecting the loosening change at the flange 4 connection. At the same time, the monitored data is transmitted to the remote terminal through the data acquisition unit 10, and an early warning is issued when abnormal data is detected, realizing real-time monitoring of the loosening of the flange connection in all directions.

[0027] The connecting pad 5 also has vertical connecting grooves 501 symmetrically arranged on both sides of the bolt 401. Springs 502 are installed in the upper and lower sets of connecting grooves 501 at the same horizontal position. At each end of the springs 502, there is a pressure plate 503 that can slide inside the connecting groove 501. A pressure sensor 504 is installed in the connecting groove 501, in contact with the pressure plate 503. The pressure sensor 504 is also located on the opposite side of the corresponding pressure plate 503 relative to the spring 502.

[0028] Under normal conditions, the spring 502 is compressed by the two sets of connecting pads 5 and applies a stable elastic force to the pressure plate 503, so that the pressure sensor 504 can detect the reference pressure. When the flange 4 is slightly separated due to the loosening of the bolt 401, the pressure between the two sets of connecting pads 5 decreases, the spring 502 releases its elastic force, and the pressure plate 503 moves. At this time, the reference pressure monitored by the pressure sensor 504 also changes, thus reflecting whether the preload of the bolt 401 has loosened, providing key data for loosening warning.

[0029] Furthermore, the hemispherical groove design of the ball cavity 6 provides a wrapping constraint for the ball 601, preventing it from falling out. The monitoring ends of the axial sensor 701 and the radial sensor 801 are arc-shaped and contact the outer surface of the ball 601. This allows for a closer contact, increasing the contact area between the axial sensor 701 and the radial sensor 801 and the ball 601. This ensures that the axial or radial force on the ball 601 is transmitted more evenly to the sensor, enabling the sensor to more accurately detect the magnitude and trend of force changes, thus improving the accuracy and reliability of the monitoring data.

[0030] When the wind turbine tower is in operation, its axis is usually vertical. When the ball bearing 601 is displaced inside the ball bearing cavity 6, the monitoring end of the axial sensor 701 will detect the change in the axial force transmitted by the ball bearing 601, and thus determine the tilt direction of the wind turbine tower. Meanwhile, the radial sensor 801 will detect the change in the radial force transmitted by the ball bearing 601, that is, the change in the vertical direction, so as to re-monitor the looseness between the two sets of flanges 4, and improve the accuracy and reliability of the monitoring data.

[0031] On the left and right sides and the inner side of the connecting pad 5, there are symmetrical through holes 9 relative to the bolt 401. The two through holes 9 on the same side are connected by the first mounting hole 7, the ball bearing cavity 6 and the second mounting hole 8. The through holes 9 are also provided with waterproof connectors 901 at their ends. Thus, by setting the through holes 9, when installing the pressure sensor 504, the axial sensor 701 and the radial sensor 801, the sensor cables are led out from the through holes 9 and connected to the data acquisition unit 10. The waterproof connectors 901 provide protection against moisture and dust intrusion, thus protecting the internal sensors.

[0032] Pressure sensor 504, axial sensor 701, and radial sensor 801 are all electrically connected to data acquisition unit 10 via wires. Data acquisition unit 10 has a built-in wireless transmission module and is connected to a remote monitoring terminal.

[0033] By configuring the data acquisition unit 10, when the pressure sensor 504, axial sensor 701, and radial sensor 801 detect loosening at the connection between the lower tower 2 and the upper tower 3, the signal can be transmitted to the remote monitoring terminal and an early warning can be issued. At the same time, multiple sensors can prevent false alarms from a single sensor. During monitoring, if the signal of a single sensor is abnormal while the signals of other sensors are stable, it can be determined as an interference signal, thus avoiding invalid early warnings.

[0034] Finally, several sets of reinforcing rods 101 are also equidistantly distributed between the foundation 1 and the lower tower 2. This layout can effectively enhance the support effect of the foundation 1 on the lower tower 2, thereby improving the stability of the entire wind turbine tower in the face of strong winds in the natural environment, thus ensuring the safe and stable operation of the wind turbine tower.

Claims

1. A device for monitoring loosening at the flange connection of a wind turbine tower, characterized in that, The device includes a foundation (1), a lower tower (2) is provided on the foundation (1), and an upper tower (3) is provided on the top of the lower tower (2). A set of flanges (4) is provided at the top of the lower tower (2) and the bottom of the upper tower (3). A connecting gasket (5) is provided on the opposite side of each of the two sets of flanges (4). The connecting gasket (5) of the same set is fixedly connected to the flange (4) by bolts (401) and nuts (402). A data acquisition device (10) is also provided on the inner wall of the lower tower (2). Inside the connecting pad (5), there are ball bearing cavities (6) symmetrically arranged on both sides of the bolt (401). Ball bearings (601) are provided in the ball bearing cavities (6). The ball bearing cavities (6) are connected to the connecting pad (5) by a first mounting hole (7) and a second mounting hole (8). The first mounting hole (7) faces the axis of the lower tower (2) and the upper tower (3). The second mounting hole (8) faces the side of the connecting pad (5) and is perpendicular to the direction of the first mounting hole (7). An axial sensor (701) is provided in the first mounting hole (7). A radial sensor (801) is provided in the second mounting hole (8). The ball bearings (601) can contact the axial sensor (701) and the radial sensor (801).

2. The wind turbine tower flange connection loosening monitoring device according to claim 1, characterized in that, The vertical cross section of the connecting gasket (5) is "L" shaped. The two inner sides of the connecting gasket (5) partially cover the top and inner sides of the flange (4), and the two sets of connecting gaskets (5) together form a "C" shape. The connecting pad (5) is also provided with vertical connecting grooves (501) symmetrically arranged on both sides of the bolt (401). The upper and lower sets of the connecting grooves (501) located at the same horizontal position are provided with springs (502). At the upper and lower ends of the springs (502), pressure plates (503) that can slide inside the connecting grooves (501) are provided.

3. The wind turbine tower flange connection loosening monitoring device according to claim 2, characterized in that, A pressure sensor (504) is provided in the connecting groove (501) and is in contact with the pressure plate (503). The pressure sensor (504) is also located on the other side of the corresponding pressure plate (503) relative to the spring (502).

4. The wind turbine tower flange connection loosening monitoring device according to claim 3, characterized in that, The pressure sensor (504), the axial sensor (701), and the radial sensor (801) are all electrically connected to the data acquisition unit (10) via wires. The data acquisition unit (10) has a built-in wireless transmission module and is connected to a remote monitoring terminal.

5. The wind turbine tower flange connection loosening monitoring device according to claim 2, characterized in that, On the left and right sides and the inner side of the connecting pad (5), there are symmetrical thread holes (9) relative to the bolt (401). The two thread holes (9) on the same side are connected by the first mounting hole (7), the ball cavity (6) and the second mounting hole (8). The thread hole (9) is provided with a waterproof connector (901) at the end.

6. The wind turbine tower flange connection loosening monitoring device according to claim 1, characterized in that, The ball cavity (6) is a hemispherical groove, and the ball (601) protrudes from the connecting pad (5) and contacts the flange (4).

7. The wind turbine tower flange connection loosening monitoring device according to claim 1, characterized in that, The monitoring ends of both the axial sensor (701) and the radial sensor (801) are arranged in an arc shape and are in contact with the ball (601).

8. The wind turbine tower flange connection loosening monitoring device according to claim 1, characterized in that, The detection end of the axial sensor (701) is oriented toward the central axis of the lower tower (2) and the upper tower (3), and the monitoring end of the radial sensor (801) is perpendicular to the detection end of the axial sensor (701).

9. The wind turbine tower flange connection loosening monitoring device according to claim 1, characterized in that, Several sets of reinforcing rods (101) are equidistantly distributed between the foundation (1) and the lower tower (2).

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