A method for verifying the inclination angle of a floating wind turbine

Abstract

The present invention discloses a method for checking the inclination angle of a floating wind turbine. Select a time when the wind and waves are small, stop the wind turbine, lock the wind wheel to make the three blades stop rotating; above the nacelle, hang a cable to the trident star platform, and the cable suspends a heavy object; loosen the chain stopper on the floating barrel one by one to make the floating barrel in a free floating state; make the nacelle yaw clockwise. During the yawing process of the nacelle, the inclination angle of the tower barrel will present a shape similar to a sine wave. If the mean value of the sine wave is 0, the inclination angle sensor does not need to be corrected. If the mean value of the sine wave is not 0, the inclination angle sensor needs to be corrected, and the mean value of the sine wave is the correction value; after the correction is completed, remove the heavy object and the cable, and readjust the length of the anchor chain and tighten the chain stopper. The present invention can accurately check the accuracy of the inclination angle sensor, make timely corrections, ensure that the wind turbine is in a balanced state, and thus ensure the safety of the operation of the wind turbine.

Description

Technical Field

[0001] The present invention relates to the technical field of floating wind turbines, and in particular to a method for checking the inclination angle of a floating wind turbine. Background Art

[0002] Offshore fixed wind turbines drive steel structures into the seabed through different foundation forms, and 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 an offshore floating wind turbine and a fixed wind turbine is that the wind turbine is installed on a floating body, and the floating body is connected to the seabed through an anchor chain. Relying on the gravity of the anchor chain, the friction between the anchor chain and the seabed, and the grip between the anchor and the seabed, the floating wind turbine floats in a small area of the sea area. Under the combined action of wind, wave and current, the floating wind turbine undergoes multi-degree-of-freedom motion, and the floating body is also at risk of tilting due to leakage caused by being hit by external ships. Therefore, the floating wind turbine has very high requirements for the accuracy of inclination measurement. If the inclination measurement is incorrect, when there is a real large inclination angle, if the measured value is too small and does not trigger the alarm threshold, there will be extremely high operation safety risks.

[0004] The current method for measuring the inclination angle of a floating wind turbine is as follows: An inclination sensor is installed inside the tower. In the dock, when there is light wind and small waves, seawater is injected 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. Then, the data of the inclination sensor is read. If the value of the inclination 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, and the anchor chain is lowered from the floating barrel to the seabed. When the wind turbine is running, the value of this inclination sensor is used as a reference. When the inclination angle exceeds the set threshold, an alarm signal is issued. If it is suspected that the inclination measurement is incorrect, a time of light wind and small waves is selected again, the wind turbine is shut down, and the draft scales on the outside of the three floating barrels are observed. If the scales are inconsistent, the floating barrels are re-injected with water to level them, and the value of the inclination sensor is corrected again.

[0006] The above method has the following problems:

[0007] The wind and waves in the dock are small, the waterline outside the buoys does not fluctuate much, and there is no anchor chain installed under the wind turbine at the dock. There is no situation where the balance of the entire wind turbine is affected by the force of some anchor chains. The method of correcting the inclination by observing whether the waterlines outside the three buoys are consistent is relatively accurate. However, when the wind turbine is in the designated sea area, the wind and waves are larger than the dock, resulting in large fluctuations in the waterlines outside the three buoys, making it difficult to read the accurate draft scale. In addition, when the wind turbine is in the designated sea area, anchor chains are installed under the three buoys. The anchor chains under some buoys are in a relaxed state, and the anchor chains under some buoys are in a stressed state. The anchor chains in a stressed state will inevitably affect the balance of the entire wind turbine, thereby making the method of observing the waterlines outside the three buoys invalid, resulting in the inability to verify the accuracy of the inclination sensor. Summary of the invention

[0008] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to propose an accurate and reliable method for verifying the inclination angle of a floating wind turbine.

[0009] To achieve the above object, the technical solution provided by the present invention is: a method for verifying the inclination angle of a floating wind turbine, performing the following operations:

[0010] Choose a time when the wind and waves are light, stop the wind turbine, lock the wind rotor, and make the three blades stop rotating and keep them still;

[0011] Above the nacelle, hang a cable to the three-pronged star-shaped platform, and hang a heavy object on the cable. The function of the heavy object is to make the center of gravity of the nacelle, blades and heavy object as far away from the center line of the tower as possible;

[0012] Loosen the chain stoppers on the buoys one by one, so that all the anchor chains connecting the three buoys are in a slack state, in order to make the buoys float freely;

[0013] Let the cabin yaw clockwise. During the yaw process, the cabin will drive the cable and the weight to rotate together. Since the center of gravity of the cabin, blades and weight deviates from the center line of the tower, the tower inclination will present a shape similar to a sine wave during the yaw process of the cabin. If the mean value of the sine wave is 0, the inclination sensor does not need to be corrected. If the mean value of the sine wave is not 0, the inclination sensor needs to be corrected, and the mean value of the sine wave is the correction value.

[0014] After the correction is completed, remove the weight and cable, readjust the anchor chain length and tighten the chain stopper.

[0015] Furthermore, the wind turbine includes a three-pronged star-shaped platform, three pontoons, anchor chains, a tower, and a nacelle with a wind wheel. The tower is installed at the intersection of the three arms of the three-pronged star-shaped platform. An inclination sensor for measuring the inclination of the tower is installed at the bottom of the tower. The nacelle is installed at the top of the tower and can drive the blades of the wind wheel to yaw and rotate around the center line of the tower according to different wind directions. A pontoon is installed at the end of each arm of the three-pronged star-shaped platform, and a chain stopper is installed on each pontoon. The chain stopper is connected to the anchor chain, and the lower end of the anchor chain is connected to the seabed.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] The method of the present invention can accurately verify the accuracy of the inclination sensor, correct it in time, ensure that the wind turbine is in a balanced state, thus guaranteeing the safety of the operation of the wind turbine. The entire method has a low implementation cost and high accuracy, has practical application value, and is worthy of promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a perspective view of a floating wind turbine.

[0019] Figure 2 is a side view of a floating wind turbine.

[0020] Figure 3 is a top view of a floating wind turbine.

[0021] Figure 4 is a schematic diagram of the inclination change during the yawing of the nacelle. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The present invention will be further described below in conjunction with specific embodiments.

[0023] Refer to Figures 1 to 4 As shown, the floating wind turbine mainly consists of a three-pronged star-shaped platform 1, three pontoons 2, anchor chains 3, a tower 6, blades 8, a nacelle 9, etc.

[0024] The tower 6 is installed at the intersection of the three arms of the three-pronged star-shaped platform 1. An inclination sensor 11 is installed at the bottom of the tower 6 for measuring the inclination of the tower 11.

[0025] A pontoon 2 is installed at the end of each arm of the three-pronged star-shaped platform 1, and a chain stopper 4 is installed on each pontoon 2. The chain stopper 4 is connected to the anchor chain 3, and the lower end of the anchor chain 3 is connected to the seabed.

[0026] The nacelle 9 is installed at the top of the tower 6. The nacelle 9 can drive the blades 8 to yaw and rotate around the center line 10 of the tower 6 according to different wind directions.

[0027] After the floating wind turbine is leveled at the dock and towed to the designated sea area for operation, if it is suspected that the inclination measurement is incorrect, the following inclination verification method can be adopted:

[0028] Select a time when the wind and waves are small, stop the wind turbine, lock the wind wheel, and let the three blades 8 stop rotating and remain stationary.

[0029] Under normal circumstances, the center of gravity position formed by the nacelle 9 and the blades 8 is not very far from the midline 10 of the tower barrel 6. Therefore, on the nacelle 9, hang a cable 12 to the three-pronged star-shaped platform 1, and a heavy object 13 is suspended from the cable 12. The function of the heavy object 13 is to make the center of gravity position 5 formed by the nacelle 9, the blades 8, and the heavy object 13 as far away from the midline 10 of the tower barrel 6 as possible.

[0030] Loosen the chain stoppers 4 on the floating barrels 2 one by one, so that all the anchor chains 3 connecting the three floating barrels 2 are in a slack state, aiming to make the floating barrels 2 in a free floating state.

[0031] Let the nacelle 9 yaw clockwise. During the yawing process of the nacelle 9, it will drive the cable 12 and the heavy object 13 to rotate slowly together. Since the center of gravity position 5 formed by the nacelle 9, the blades 8, and the heavy object 13 deviates from the midline 10 of the tower barrel 6, during the yawing process of the nacelle 9, the inclination angle of the tower barrel 6 will present a shape similar to a sine wave. If the mean value of the sine wave is 0, the inclination sensor 11 does not need to be corrected. If the mean value of the sine wave is not 0, the inclination sensor 11 needs to be corrected, and the mean value of the sine wave is the correction value.

[0032] After the correction is completed, remove the heavy object 13 and the cable 12, and readjust the length of the anchor chain 3 and tighten the chain stopper 4.

[0033] 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. An inclination angle verification method for a floating wind turbine, characterized in that The wind turbine includes a three-pronged star-shaped platform, three floating barrels, anchor chains, a tower barrel, and a nacelle with a wind wheel. The tower barrel is installed at the intersection of the three arms of the three-pronged star-shaped platform. An inclination sensor for measuring the inclination of the tower barrel is installed at the bottom of the tower barrel. The nacelle is installed at the top of the tower barrel and can drive the blades of the wind wheel to yaw and rotate around the midline of the tower barrel according to different wind directions. A floating barrel is installed at the end of each arm of the three-pronged star-shaped platform. A chain stopper is installed on each floating barrel. The chain stopper is connected to the anchor chain, and the lower end of the anchor chain is connected to the seabed. The method performs the following operations: Select a time when the wind and waves are small, stop the wind turbine, lock the wind wheel, and let the three blades stop rotating and remain stationary. Hang a cable from the nacelle to the three-pronged star-shaped platform. The cable suspends a heavy object. The function of the heavy object is to make the center of gravity of the combination of the nacelle, blades, and heavy object as far away from the midline of the tower barrel as possible. Loosen the chain stoppers on the floating barrels one by one to make all the anchor chains connecting the three floating barrels in a slack state, aiming to make the floating barrels in a free floating state. Let the nacelle yaw clockwise. During the yawing process of the nacelle, it will drive the cable and the heavy object to rotate together. Since the center of gravity of the combination of the nacelle, blades, and heavy object deviates from the midline of the tower barrel, during the yawing process of the nacelle, the inclination of the tower barrel will present a shape similar to a sine wave. If the mean value of the sine wave is 0, the inclination sensor does not need to be corrected. If the mean value of the sine wave is not 0, the inclination sensor needs to be corrected, and the mean value of the sine wave is the correction value. After the correction is completed, remove the heavy object and the cable, readjust the length of the anchor chain and tighten the chain stopper.

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