An inclination measurement and verification method for a floating wind turbine with a non-yaw structure

Abstract

The present invention discloses a method for measuring and verifying the inclination angle of a floating wind turbine with a non-yaw structure. A U-shaped part is fabricated, and the top of the laterally placed U-shaped part is tightly attached to the lower end surface of the foundation flange in the front-back direction and welded and fixed. Two identical biaxial inclination sensors are installed on the mounting surface of the U-shaped part. The inclination angle values of the biaxial inclination sensors will completely represent the inclination angle of the flange surface. A suspension bracket is installed at the height of the foundation flange surface, and the center of the suspension bracket is the center of the foundation cross-section. A steel wire is suspended at the center of the suspension bracket, and a pendant is connected to the lower end of the steel wire. A reference bracket is installed below the suspension bracket, and the center of the reference bracket is the center of the foundation cross-section. When the unit is operating normally, the inclination angles of the two sensors will be used as a reference; when there is a deviation in the inclination angles of the two sensors and it is impossible to determine which one is abnormal, there is a mechanical and stable reference object as a reference. The present invention can accurately complete the measurement and verification of the inclination angle of a floating wind turbine with a non-yaw structure.

Description

Technical Field

[0001] The present invention relates to the technical field of floating wind turbines, and in particular to a method for measuring and verifying the inclination angle of a floating wind turbine with a non-yaw structure. Background Art

[0002] For offshore fixed wind turbines, through different foundation forms, steel structures are driven into the seabed. The inclination and settlement of the tower can be monitored in real time by equipment to ensure that the tower does not tilt.

[0003] The difference between offshore floating wind turbines and fixed wind turbines is that: the wind turbine is installed on a floating body, and the floating body is connected to the seabed through anchor chains. Relying on the gravity of the anchor chains, the friction between the anchor chains and the seabed, and the gripping force between the anchors and the seabed, the floating wind turbine floats in a small area of the sea area. Under the combined action of wind, waves and currents, the floating wind turbine undergoes multi-degree-of-freedom motion, and the floating body also faces the risk of tilting due to leakage caused by being hit by external ships. Therefore, the accuracy requirement for inclination angle measurement of floating wind turbines is very high. If the inclination angle measurement is incorrect, when a real large inclination angle occurs, if the measured value is too small and does not trigger the alarm threshold, there will be great operation safety risks.

[0004] The current method for measuring the inclination angle of floating wind turbines is as follows: after the tower is manufactured in the tower factory, a tooling is welded at a specified position on the inner wall of the tower. After all the equipment such as the tower, nacelle, blades, and floating body are assembled at the dock, the inclination angle sensor is installed on this tooling. Select the time of light wind and small waves, inject seawater into the floating barrels to level them. When the draft scales on the outside of the three floating barrels are the same, it is considered that the tower is in a vertical state at this time, and then the data of the inclination angle sensor is read. If the value of the inclination angle sensor read at this time is not 0, it is corrected to 0 degrees in the program.

[0005] Subsequently, the wind turbine is towed to the designated sea area. When the wind turbine is operating, the value of this inclination angle sensor is used as a reference. When the inclination angle exceeds the set threshold, an alarm signal is issued.

[0006] The above method has the following problems:

[0007] 1. During the process of leveling the three floating barrels by injecting water, due to the existence of waves, the draft position of the floating body is not constant but fluctuates, and it is very difficult to read accurate and stable draft values; in addition, since the draft scales of the three floating barrels are read and recorded by three different groups of people, there are certain differences in the reading perspectives and methods, which will inevitably affect the leveling effect; the three floating barrels are far away from the tower, and the floating barrels and the tower are connected by platforms. It is very difficult to ensure the consistency of the platforms and floating barrels in the three directions during the processing and installation process, that is, the scale lines with the same value of the three floating barrels may not be exactly in the same plane. Although the drafts of the three floating barrels are adjusted to be the same, the tower is not vertical.

[0008] 2. Over time, the inclination sensor may experience zero drift or error, and its accuracy gradually decreases. Therefore, relying solely on the inclination sensor for inclination measurement, it is difficult to ensure accuracy. Moreover, once the sensor fails, the true inclination cannot be verified.

[0009] 3. When the inclination sensor fails and needs to be replaced, and the water volume in the floating barrel also changes, the replaced inclination sensor will lack a reference. Because for a floating wind turbine in the sea, due to the mooring force under the floating barrel, it is more difficult to level than during installation and commissioning at the dock.

[0010] 4. For a floating wind turbine with a yaw structure, by yawing the nacelle one full circle, the tower inclination will show a sine wave change, and the mean value of the sine wave can be used as the correction value for the inclination sensor. However, this method is not applicable to floating wind turbines without a yaw structure.

[0011] 5. The tooling for installing the inclination sensor is directly welded to the inner wall of the tower. The sensor measures the inclination of the inner wall, which does not represent the inclination of the tower. Because the tower is conical in shape, smaller at the top and larger at the bottom, so the inner wall of the tower is inclined and not vertical. Summary of the Invention

[0012] The object of the present invention is to overcome the deficiencies of the prior art and propose an accurate and reliable inclination measurement and verification method for a floating wind turbine without a yaw structure.

[0013] To achieve the above object, the technical solution provided by the present invention is: an inclination measurement and verification method for a floating wind turbine without a yaw structure, based on the following characteristics:

[0014] The tower of the wind turbine is composed of multiple tower sections connected in sequence by flanges. The tower is connected to the foundation by a flange, and the two flanges are fastened by bolts. The flatness of the flange end face is high. If all directions of the flange end face are in a horizontal state, it means the tower is vertical; if any direction of the flange end face shows a non-horizontal state, it means the tower is inclined. Utilizing this characteristic, when making the foundation, stand the foundation up and use a spirit level to measure the front-back direction and left-right direction of the flange end face of the foundation. When the measurements in both the front-back direction and the left-right direction are zero, it means the foundation is vertical;

[0015] Keep the base vertical and fabricate a U-shaped part with two right-angled corners. Place the U-shaped part on its side, i.e., the two vertical sides of the U-shaped part are parallel up and down, and its opening faces the inside of the base. Press the top of the side-placed U-shaped part tightly against the lower end face of the flange on the top of the base in the front-back direction and maintain the tight contact state. Then weld the U-shaped part to the inner wall of the base. At this time, the mounting surface of the U-shaped part is completely parallel to the flange surface. Install two identical dual-axis inclinometers on the mounting surface of the U-shaped part. The X-axis of the dual-axis inclinometer is parallel to the front-back direction of the base, and the Y-axis of the dual-axis inclinometer is parallel to the left-right direction of the base. The two dual-axis inclinometers are connected to the collector. At this time, the front-back and left-right inclinations of the dual-axis inclinometers should both be zero. If not, perform zero correction on the dual-axis inclinometers until the inclination is corrected to zero. At this time, the inclination values of the dual-axis inclinometers will exactly represent the inclination of the flange surface. Then remove the two dual-axis inclinometers and the collector.

[0016] When assembling the floating wind turbine at the dock, select light wind and small wave weather. After assembly, reinstall the previous two dual-axis inclinometers at the U-shaped part and connect them to the collector. When adjusting the level by filling water into the floating barrel, the inclination data at this time is used as a reference for whether the tower barrel is vertical. If the inclinations of both the X-axis and the Y-axis are zero, it means the tower barrel is vertical. If any one of the inclinations of the X-axis and the Y-axis is not zero, it means the floating barrel is not leveled and the tower barrel is not vertical, and the water volume needs to be continuously adjusted until the inclinations of both the X-axis and the Y-axis are zero.

[0017] Next, install a suspension bracket at the height of the flange surface of the base. The center of the suspension bracket is the center of the base cross-section. Hang a steel wire at the center position of the suspension bracket. Connect a pendant to the lower end of the steel wire. The total length of the steel wire and the pendant is n. Install a reference bracket at a distance of m below the suspension bracket, where m > n. The center of the reference bracket is the center of the base cross-section. At this time, the pendant just aligns with the center of the reference bracket.

[0018] Finally, tow the floating wind turbine to the designated sea area and lower the anchor chain to the seabed. Only the bottom of one floating barrel of the floating wind turbine is connected by the anchor chain. The wind turbine will operate normally under the action of the wind. When the wind direction changes, the wind turbine will rotate around the floating barrel connected by the anchor chain with the change of the wind direction.

[0019] When the floating wind turbine is operating normally, the inclinations of the two dual-axis inclinometers will be used as a reference.

[0020] When the inclination deviation between two biaxial inclination sensors is less than 0.1 degree, it indicates that the two biaxial inclination sensors are normal. When the X-axis inclinations of the two biaxial inclination sensors both exceed the set safety threshold, or when the Y-axis inclinations of the two biaxial inclination sensors both exceed the set safety threshold, an alarm signal is issued to prompt that the tower barrel inclination is too large, there is a safety risk, which may be caused by excessive wind and waves or an abnormality in the anchor chain.

[0021] When the deviation of the X-axis inclination or Y-axis inclination between two biaxial inclination sensors exceeds 0.1 degree, it indicates that one of the biaxial inclination sensors is abnormal, and an alarm signal will be issued to prompt that one biaxial inclination sensor is abnormal and needs to be rechecked. The recheck method is as follows: Under the state of light wind and small waves, measure the distance L between the projection point of the pendant on the reference bracket and the center point. Through the formula φ = arcsin(L / n), the true inclination angle φ of the tower barrel can be calculated. If the value of a certain biaxial inclination sensor is further away from the true inclination angle φ, it can be judged that this biaxial inclination sensor is abnormal.

[0022] Furthermore, a regular automatic inspection program is set as follows: Under the state of light wind and small waves, judge whether the values of the two biaxial inclination sensors are both less than 0.1 degree. If so, no alarm is processed. If not, an alarm signal is issued, indicating that the tower barrel is inclined, which may be due to a change in the water volume in the floating barrel, and it is necessary to recheck the water volume and level it again.

[0023] Furthermore, the floating wind turbine with a non-yaw structure includes a three-pronged star platform, three floating barrels, an anchor chain, a foundation, a tower barrel, and a main engine with blades; the main engine is fixedly connected to the tower barrel without a yaw system; the tower barrel is installed on the foundation through a flange, and the foundation is installed at the intersection of the three arms of the three-pronged star platform. Each arm end of the three-pronged star platform is installed with a floating barrel, and the bottom of one of the floating barrels is connected with an anchor chain, and the lower end of the anchor chain is connected to the seabed.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] 1. The U-shaped part installed with the biaxial inclination sensor is completely parallel to the flange surface of the tower barrel, and the value of the biaxial inclination sensor can reflect the inclination state of the tower barrel without other corrections.

[0026] 2. When there is a deviation in the inclination angles of the two biaxial inclination sensors and it is impossible to judge which one is abnormal, there is a mechanical and stable reference object as a reference. Brief Description of the Drawings

[0027] Figure 1 It is a basic schematic diagram.

[0028] Figure 2 It is a schematic diagram of the foundation and the tower barrel installed with the biaxial inclination sensor.

[0029] Figure 3 One of the schematic diagrams for installing a biaxial inclinometer and a pendant based on [the foundation].

[0030] Figure 4 Another schematic diagram for installing a biaxial inclinometer and a pendant based on [the foundation].

[0031] Figure 5 Oblique view of a floating wind turbine with a non - yaw structure.

[0032] Figure 6 Side view of a floating wind turbine with a non - yaw structure.

[0033] Figure 7 Top view of a floating wind turbine with a non - yaw structure.

[0034] Figure 8 Schematic diagram for calculating the angle of the pendant deviating from the center. Specific implementation manners

[0035] The present invention will be further described below in conjunction with specific embodiments.

[0036] See Figures 1 to 8 As shown, the floating wind turbine with a non - yaw structure mainly consists of a three - pronged star - shaped platform 1, three floating barrels 2, anchor chains 3, flanges 4, a foundation 5, a tower barrel 6, blades 8, a main engine 9, etc.

[0037] The main engine 9 is fixedly connected to the tower barrel 6, without a yaw system.

[0038] The foundation 5 is installed at the intersection of the three arms of the three - pronged star - shaped platform 1. A floating barrel 2 is installed at the end of each arm of the three - pronged star - shaped platform 1. The bottom of one of the floating barrels 2 is connected by an anchor chain 3, and the lower end of the anchor chain 3 is connected to the seabed.

[0039] Under the action of different wind directions, the wind turbine will rotate with the wind direction around the floating barrel 2 connected by the anchor chain 3.

[0040] The inclination measurement and verification method of the floating wind turbine with a non - yaw structure provided in this embodiment is based on the following characteristics:

[0041] The tower barrel 6 is formed by sequentially connecting multiple tower barrel segments through flanges 4. The tower barrel 6 is connected to the foundation 5 through the flange 4, and the two flanges 4 are fastened by bolts. The flatness of the end face of the flange 4 is very high. If all directions of the end face of the flange 4 are horizontal, it means the tower barrel 6 is vertical; if any direction of the end face of the flange 4 is non-horizontal, it means the tower barrel 6 is tilted. Utilizing this feature, when fabricating the foundation 5, the foundation 5 is erected, and the front-back direction and left-right direction of the end face of the flange 4 of the foundation 5 are measured. When the inclination angles in both the front-back direction and the left-right direction are zero, it means the foundation 5 is vertical.

[0042] Keep the foundation 5 in a vertical state, and fabricate a U-shaped part 11 with two right angles at its two corners. Place the U-shaped part 11 sideways, that is, the two vertical sides of the U-shaped part 11 are parallel up and down, and its opening faces the inside of the foundation 5. Press the top of the sideways U-shaped part 11 tightly against the lower end face in the front-back direction of the flange 4 at the top of the foundation 5 and keep it in a tight state. Then weld the U-shaped part 11 to the inner wall of the foundation 5. At this time, the installation surface of the U-shaped part 11 is completely parallel to the flange 4. Install two identical biaxial inclination sensors 12 on the installation surface of the U-shaped part 11. The X-axis of the biaxial inclination sensor 12 is parallel to the front-back direction of the foundation 5, and the Y-axis of the biaxial inclination sensor 12 is parallel to the left-right direction of the foundation 5. The biaxial inclination sensors 12 are connected to the collector 13. In theory, the inclination angles in both the front-back and left-right directions should be zero at this time. If not, perform zero correction on the biaxial inclination sensors 12 to correct the inclination angle to zero. At this time, the inclination angle value of the biaxial inclination sensors 12 will exactly represent the inclination angle of the flange 4. Then remove the biaxial inclination sensors 12 and the collector 13.

[0043] When the floating wind turbine is assembled at the dock, select a weather with light wind and small waves. First, install three floating barrels 2 and the three-pronged star-shaped platform 1, then install the foundation 5, then install the tower barrel 6, and finally install the main engine 9 and the blades 8. After assembly, reinstall the previous two biaxial inclination sensors 12 at the U-shaped part 11 and connect them to the collector 13. When the floating barrels 2 are filled with water 7 for leveling, the inclination data at this time is used as a reference for whether the tower barrel 6 is vertical. If the inclination angles of both the X-axis and the Y-axis are zero, it means the tower barrel 6 is vertical. If any one of the inclination angles of the X-axis and the Y-axis is non-zero, it means the floating barrels 2 are not leveled and the tower barrel 6 is not vertical, and the water volume needs to be continuously adjusted until the inclination angles of both the X-axis and the Y-axis are zero.

[0044] Next, install a suspension bracket 15 at the flange height of the foundation 5. The center of the suspension bracket 15 is the center of the cross-section of the foundation 5. Hang a steel wire 16 at the center position of the suspension bracket 15. A pendant 17 is connected to the lower end of the steel wire 16. The total length of the steel wire 16 and the pendant 17 is 3000 mm. Install a reference bracket 18 at a position 3100 mm below the suspension bracket 15. The center of the reference bracket 18 is the center of the cross-section of the foundation 5. At this time, the pendant 17 is just aligned with the center of the reference bracket 18.

[0045] Finally, tow the floating wind turbine to the designated sea area, lower the anchor chain 3 to the seabed, and the wind turbine will operate normally under the action of the wind. When the wind direction changes, the wind turbine will rotate with the floating barrel 2 connected by the anchor chain 3 as the center.

[0046] When the floating wind turbine is operating normally, the inclinations of the two biaxial inclination sensors 12 will be used as a reference.

[0047] When the inclination deviation of the two biaxial inclination sensors 12 is less than 0.1 degree, it indicates that the two biaxial inclination sensors 12 are normal. When the X-axis inclinations of the two biaxial inclination sensors 12 both exceed the set safety threshold, or when the Y-axis inclinations of the two biaxial inclination sensors 12 both exceed the set safety threshold, an alarm signal will be sent to prompt that the inclination of the tower barrel 6 is too large and there is a safety risk, which may be caused by excessive wind and waves, or there is an abnormality in the anchor chain 3.

[0048] When the deviation of the X-axis inclination or Y-axis inclination of the two biaxial inclination sensors 12 exceeds 0.1 degree, it indicates that one of the biaxial inclination sensors 12 has an abnormality, and an alarm signal will be sent to prompt that one of the biaxial inclination sensors 12 is abnormal and needs to be rechecked. The maintenance personnel will board the plane for inspection, and the inspection method is as follows: Under the state of light wind and small waves, measure the distance L (unit: mm) between the projection point of the pendant 17 on the reference bracket 18 and the center point. Through the formula φ = arcsin(L / 3000), the true inclination angle φ of the tower barrel 6 can be calculated. If the value of a certain biaxial inclination sensor is further away from this true inclination angle φ, it can be judged that this biaxial inclination sensor is abnormal.

[0049] In addition, a regular automatic inspection program should be set up, and the method is as follows: Under the state of light wind and small waves, judge whether the values of the two biaxial inclination sensors 12 are both less than 0.1 degree. If so, no alarm will be processed. If not, an alarm signal will be sent to indicate that the tower barrel 6 has a certain inclination, which may be due to a change in the water volume 7 in the floating barrel 2, and the water volume 7 needs to be rechecked and leveled again.

[0050] The above-described embodiments are only the preferred embodiments of the present invention, and do not limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for measuring and verifying the inclination angle of a floating wind turbine with a non-yaw structure, characterized in that, Based on the following characteristics: The tower barrel of a wind turbine is composed of multiple tower barrel segments connected in sequence by flanges. The tower barrel is connected to the foundation by a flange, and the two flanges are fastened by bolts. The flatness of the flange end face is high. If the flange end face is horizontal in all directions, it means the tower barrel is vertical; if there is a non-horizontal state in any direction of the flange end face, it means the tower barrel is tilted. Utilizing this characteristic, when making the foundation, stand the foundation up and use a spirit level to measure the front-back direction and left-right direction of the flange end face of the foundation. When the measurements in both the front-back direction and the left-right direction are zero, it means the foundation is vertical; Keep the foundation in a vertical state and make a U-shaped part. The two corners of the U-shaped part are right angles. Place the U-shaped part on its side, that is, the two vertical sides of the U-shaped part are parallel up and down, and its opening faces the inside of the foundation. Press the top of the U-shaped part placed on its side tightly against the lower end face of the flange in the front-back direction at the top of the foundation, and keep it in a tight state. Then weld the U-shaped part to the inner wall of the foundation. At this time, the installation surface of the U-shaped part is completely parallel to the flange surface. On the installation surface of the U-shaped part, install two identical biaxial inclination sensors. The X-axis of the biaxial inclination sensor is parallel to the front-back direction of the foundation, and the Y-axis of the biaxial inclination sensor is parallel to the left-right direction of the foundation. The two biaxial inclination sensors are connected to a collector. At this time, the front-back and left-right inclinations of the biaxial inclination sensors should both be zero. If not, perform zero correction on the biaxial inclination sensors to correct the inclination to zero. At this time, the inclination values of the biaxial inclination sensors will exactly represent the inclination of the flange surface. Then remove the two biaxial inclination sensors and the collector; When assembling a floating wind turbine at the dock, select a day with light wind and small waves. After assembly, reinstall the previous two biaxial inclination sensors at the U-shaped part and connect them to the collector; when adjusting the water level of the floating barrel to be level, the inclination data at this time is used as a reference for whether the tower barrel is vertical. If the inclinations of both the X-axis and the Y-axis are zero, it means the tower barrel is vertical. If any one of the inclinations of the X-axis and the Y-axis is not zero, it means the floating barrel is not leveled and the tower barrel is not vertical, and the water volume needs to be continuously adjusted until the inclinations of both the X-axis and the Y-axis are zero; Next, install a suspension bracket at the height of the flange surface of the foundation. The center of the suspension bracket is the center of the foundation cross-section. Hang a steel wire at the center position of the suspension bracket. The lower end of the steel wire is connected to a pendant. The total length of the steel wire and the pendant is n. Install a reference bracket at a distance of m below the suspension bracket, where m > n. The center of the reference bracket is the center of the foundation cross-section. At this time, the pendant just aligns with the center of the reference bracket; Finally, tow the floating wind turbine to the designated sea area and lower the anchor chain to the seabed. Only the bottom of one floating barrel of the floating wind turbine is connected by the anchor chain. The wind turbine will operate normally under the action of the wind. When the wind direction changes, the wind turbine will rotate around the floating barrel connected by the anchor chain with the change of the wind direction; When the floating wind turbine is operating normally, the inclinations of the two biaxial inclination sensors will be used as a reference; When the inclination deviation between two biaxial inclination sensors is less than 0.1 degree, it indicates that the two biaxial inclination sensors are normal. When the X-axis inclinations of both biaxial inclination sensors exceed the set safety threshold, or when the Y-axis inclinations of both biaxial inclination sensors exceed the set safety threshold, an alarm signal is issued to prompt that the tower barrel inclination is too large, there is a safety risk, which is caused by excessive wind and waves, or there is an abnormality in the anchor chain. When the deviation of the X-axis inclination or Y-axis inclination between two biaxial inclination sensors exceeds 0.1 degree, it indicates that one of the biaxial inclination sensors is abnormal, and an alarm signal will be issued to prompt that one biaxial inclination sensor is abnormal and needs to be rechecked. The recheck method is as follows: Under the state of light wind and small waves, measure the distance L between the projection point of the pendant on the reference bracket and the center point. Through the formula φ = arcsin(L / n), the true inclination angle φ of the tower barrel can be calculated. If the value of a certain biaxial inclination sensor is further away from the true inclination angle φ, it can be judged that this biaxial inclination sensor is abnormal.

2. The inclination measurement and verification method of a floating wind turbine with a non-yaw structure according to claim 1, characterized in that Set a regular automatic inspection program, the method is as follows: Under the state of light wind and small waves, judge whether the values of the two biaxial inclination sensors are both less than 0.1 degree. If so, no alarm is processed. If not, an alarm signal is issued to indicate that the tower barrel is inclined, which is due to the change in the water volume in the floating barrel, and the water volume needs to be rechecked and leveled again.

3. A tilt measurement and verification method for a floating wind turbine with a non-yaw structure according to claim 1, characterized in that, The floating wind turbine with a non-yaw structure includes a three-pronged star-shaped platform, three floating barrels, an anchor chain, a foundation, a tower barrel and a main engine with blades; the main engine is fixedly connected to the tower barrel without a yaw system; the tower barrel is installed on the foundation through a flange, and the foundation is installed at the intersection of the three arms of the three-pronged star-shaped platform. Each arm end of the three-pronged star-shaped platform is equipped with a floating barrel, and the bottom of one of the floating barrels is connected by an anchor chain, and the lower end of the anchor chain is connected to the seabed.

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