A displacement detection method for a floating wind turbine

Abstract

The present invention discloses a displacement detection method for a floating wind turbine. In this method, sonar transmitters are installed at the center of the floating foundation platform of the floating wind turbine and on each floating barrel, and iron chains are lowered. Weights are tied to the iron chains, and sonar receivers are installed on the weights. There is a chain stopper at the front end of the lowered iron chain. The lowering of the iron chain is controlled by the chain stopper. By measuring the vertical distance between the sonar transmitter and the corresponding sonar receiver and the offset distance after a typhoon occurs, the horizontal displacements generated by all floating barrels and the floating foundation platform after a typhoon can be calculated, and thus the true displacements of all anchors can be truly reflected, so as to accurately evaluate the safety of the floating wind turbine. The method of the present invention has the advantages of simple and reliable operation, strong feasibility, high precision, etc.

Description

Technical Field

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

[0002] The sea contains rich wind energy resources. Developing and utilizing the offshore wind energy resources in the deep sea is the future trend, and floating wind turbines will be the mainstream in the future.

[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 at a relatively fixed position.

[0004] During a typhoon, the wind turbine is subjected to the thrust of strong winds, and the floating body is pushed by waves and currents. The force on the anchor chain increases, and the position of the anchor may change. The entire floating wind turbine may drift; if the drift displacement is too large, it may collide with other wind turbines or offshore facilities, posing a safety hazard.

[0005] Therefore, it is necessary to detect the displacement of the floating wind turbine during a typhoon to verify the safety of the anchor chain design.

[0006] The disadvantages of the existing technical solutions are as follows:

[0007] 1. The current positioning method is generally through satellite positioning. However, satellite positioning has application defects in floating wind turbines because the floating wind turbine itself will drift within a small range with different wind directions. It is normal for the position between a certain anchor among the three anchors and the seabed to change. Only when large-scale displacement changes occur between all three anchors and the seabed is it abnormal. However, satellite positioning can only measure how much displacement the wind turbine above the water surface has undergone and cannot measure how much displacement the anchor underwater has undergone.

[0008] 2. The accuracy of satellite positioning is relatively low and cannot achieve precise measurement. Summary of the Invention

[0009] The purpose of the present invention is to overcome the disadvantages and deficiencies of the existing technology, and propose a displacement detection method for floating wind turbines, which is simple to operate, highly feasible, and has high accuracy.

[0010] To achieve the above object, the technical solution provided by the present invention is: a displacement detection method for a floating wind turbine. The floating wind turbine includes a floating foundation platform, floating barrels, anchor chains, anchors and a wind turbine. The wind turbine is installed at the central position of the floating foundation platform. The floating foundation platform is a multi-arm structure with multiple support arms extending horizontally outwards. The multiple support arms are evenly distributed along the circumferential direction of the platform. A floating barrel is installed at the bottom end of each support arm. A bottom of each floating barrel is connected to an anchor chain, and the end of the anchor chain is connected to the seabed by an anchor. This method requires the configuration of iron chains, weights, sonar receivers, sonar transmitters and a chain stopper with an automatic torque detection function. The specific implementation process is as follows:

[0011] First, lower an iron chain downwards from each floating barrel and the center of the floating foundation platform respectively. A weight is tied to the iron chain, and a sonar receiver is installed on the weight. There is a chain stopper at the front end of the lowered iron chain, that is, a chain stopper is installed on each floating barrel and the floating foundation platform. The chain stopper has the function of automatic torque detection. When the weight is being lowered and the force on the iron chain reaches a preset value, the chain stopper loosens, allowing the iron chain to be automatically lowered continuously. When the weight reaches the seabed, the force on the iron chain becomes smaller, and the chain stopper will lock the iron chain, so that the weight and the sonar receiver are just located on the seabed, and the iron chain is in a nearly vertical state.

[0012] At the same time, a sonar transmitter is installed on each floating barrel and the center of the floating foundation platform. The sonar transmitter can detect the initial distance between it and the corresponding sonar receiver. Define the initial distance between the sonar transmitter on a certain floating barrel and the corresponding sonar receiver as L1. Since the iron chain is in a nearly vertical state, it can be approximately considered that the initial distance L1 is the vertical distance H1 between the sonar transmitter and the corresponding sonar receiver.

[0013] During a typhoon, the anchor chain and the anchor cannot fix the entire floating wind turbine in a certain position. The anchor will have a displacement change, the iron chain will drag the weight, the force on the iron chain increases, the chain stopper loosens, and the iron chain continues to be lowered, while the weight stays in place until the anchor stops moving. At this time, the sonar transmitter on the above-mentioned certain floating barrel detects the final distance L11 between it and the corresponding sonar receiver.

[0014] Through trigonometric functions, using L11 and H1, the horizontal displacement of the above-mentioned certain floating barrel can be calculated, and this horizontal displacement represents the real displacement of the corresponding anchor. Similarly, following the above process, the horizontal displacements of other floating barrels and the horizontal displacement of the center of the floating foundation platform can be calculated.

[0015] Finally, through the calculated horizontal displacements of all floating barrels and the horizontal displacement of the center of the floating foundation platform, the real displacements of all anchors can be truly reflected, so as to accurately evaluate the safety of the floating wind turbine.

[0016] Furthermore, the weight block is a circular weight block.

[0017] Furthermore, the floating foundation platform is formed with three support arms.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] The present invention provides a method for detecting displacement by using sonar equipment. The whole method is simple, reliable, highly feasible, and has high precision. It can accurately measure how much displacement has occurred to the underwater anchor, providing a reliable basis for the safety assessment of floating wind turbines, having practical application value, and being worthy of promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the front view of the floating wind turbine.

[0021] Figure 2 is the top view of the floating wind turbine.

[0022] Figure 3 is one of the schematic diagrams of displacement detection of the floating wind turbine.

[0023] Figure 4 is another schematic diagram of displacement detection of the floating wind turbine.

[0024] Figure 5 is the third schematic diagram of displacement detection of the floating wind turbine.

[0025] Figure 6 is the fourth schematic diagram of displacement detection of the floating wind turbine. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The present invention will be further described in detail below in conjunction with the embodiments and the drawings, but the embodiments of the present invention are not limited thereto.

[0027] Refer to Figure 1 and Figure 2 As shown, the floating wind turbine disclosed in this embodiment includes a floating foundation platform 1, a floating barrel 2, an anchor chain 3, an anchor 4, and a wind turbine 5. The wind turbine 5 is installed at the central position of the floating foundation platform 1. The floating foundation platform 1 is a three-arm structure that horizontally extends outward with three support arms. The three support arms are evenly distributed along the circumference of the platform. A floating barrel 2 is installed at the bottom end of each support arm. A bottom of each floating barrel 2 is connected to an anchor chain 3, and the end of the anchor chain 3 is connected to the seabed by the anchor 4.

[0028] Under normal circumstances, the anchor chain 3 is in a relatively loose state. With the changes in wind direction, wave direction, and flow direction, the wind turbine 5 will undergo small displacements.

[0029] Refer toFigures 3 to 6 As shown in the figure, for the displacement detection method of the floating wind turbine unit disclosed in this embodiment, a steel chain 11, a circular weight 12, a sonar receiver 13, a sonar transmitter 15, and a chain stopper 14 with an automatic torque detection function need to be configured. The specific implementation process is as follows:

[0030] First, a steel chain 11 is lowered down from the center of each floating barrel 2 and the floating foundation platform 1 respectively. The end of the steel chain 11 is tied with a circular weight 12, and a sonar receiver 13 is installed on the circular weight 12. There is a chain stopper 14 at the front end of the lowered steel chain 11, that is, a chain stopper 14 is installed on each floating barrel 2 and the floating foundation platform 1. The chain stopper 14 has the function of automatic torque detection. When the circular weight 12 is being lowered and the force on the steel chain 11 reaches the preset value, the chain stopper 14 releases, allowing the steel chain 11 to keep lowering automatically. When the circular weight 12 reaches the seabed, the force on the steel chain 11 becomes smaller, and the chain stopper 14 will lock the steel chain 11, so that the circular weight 12 and the sonar receiver 13 are just located on the seabed, and the steel chain 11 is in a nearly vertical state;

[0031] At the same time, a sonar transmitter 15 is installed on the center of each floating barrel 2 and the floating foundation platform 1. The sonar transmitter 15 can detect the initial distance between it and the corresponding sonar receiver 13. Define the initial distance between the sonar transmitter 15 on a certain floating barrel 2 and the corresponding sonar receiver 13 as L1. Since the steel chain 11 is in a nearly vertical state, it can be approximately considered that the initial distance L1 is the vertical distance H1 between the sonar transmitter 15 and the corresponding sonar receiver 13;

[0032] During a typhoon, if the wind force is too large and the anchor chains 3 and the anchors 4 cannot fix the entire floating wind turbine unit in a certain position, the anchor 4 will have a displacement change. The steel chain 11 will drag the circular weight 12, the force on the steel chain 11 increases, the chain stopper 14 releases, and the steel chain 11 continues to lower, while the circular weight 12 stays in place until the anchor 4 stops moving. At this time, the sonar transmitter 15 on the above-mentioned certain floating barrel 2 detects the final distance between it and the corresponding sonar receiver 13 as L11;

[0033] Through trigonometric functions, using L11 and H1 (approximately equal to L1), the horizontal displacement D1 of the above-mentioned certain floating barrel 2 can be calculated. This horizontal displacement D1 represents the actual displacement that the corresponding anchor 4 has undergone. Similarly, according to the above process, the horizontal displacements D2 and D3 of the other two floating barrels 2, as well as the horizontal displacement D0 of the center of the floating foundation platform 1, can be calculated;

[0034] Finally, through the calculated horizontal displacements D0, D1, D2, and D3, the actual displacements that all the anchors 4 have undergone can be truly reflected, thus providing a reliable basis for evaluating the safety of the floating wind turbine unit.

[0035] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A displacement detection method for a floating wind turbine, the floating wind turbine comprising a floating foundation platform, pontoons, anchor chains, anchors and a wind turbine. The wind turbine is installed at the central position of the floating foundation platform. The floating foundation platform is a multi-arm structure with multiple support arms extending horizontally outwards. The multiple support arms are evenly distributed along the circumferential direction of the platform. A pontoon is installed at the bottom end of each support arm. A bottom of each pontoon is connected with an anchor chain, and a end of the anchor chain is connected to the seabed with an anchor; It is characterized in that, This method requires the configuration of iron chains, weights, sonar receivers, sonar transmitters and chain stoppers with an automatic torque detection function. The implementation process is as follows: First, lower an iron chain downwards from each pontoon and the center of the floating foundation platform respectively. A weight is tied to the iron chain, and a sonar receiver is installed on the weight. There is a chain stopper at the front end of the lowered iron chain, that is, a chain stopper is installed on each pontoon and the floating foundation platform. The chain stopper has the function of automatic torque detection. When the iron chain is stressed to reach a preset value during the lowering of the weight, the chain stopper loosens, enabling the iron chain to be automatically lowered all the time. When the weight reaches the seabed, the stress on the iron chain becomes smaller, and the chain stopper will lock the iron chain, so that the weight and the sonar receiver are just located on the seabed, and the iron chain is in a nearly vertical state; At the same time, a sonar transmitter is installed on each pontoon and the center of the floating foundation platform. The sonar transmitter can detect the initial distance between it and the corresponding sonar receiver. Define the initial distance between the sonar transmitter on a certain pontoon and the corresponding sonar receiver as L1. Since the iron chain is in a nearly vertical state, it can be approximately considered that the initial distance L1 is the vertical distance H1 between the sonar transmitter and the corresponding sonar receiver; During a typhoon, the anchor chain and the anchor cannot fix the entire floating wind turbine at a certain position. The anchor will have a displacement change. The iron chain will drag the weight, the stress on the iron chain increases, the chain stopper loosens, and the iron chain continues to be lowered, while the weight stays in place until the anchor stops moving. At this time, the sonar transmitter on the above-mentioned certain pontoon detects the final distance L11 between it and the corresponding sonar receiver; Through trigonometric functions, using L11 and H1, the horizontal displacement of the above-mentioned certain pontoon can be calculated, and this horizontal displacement represents the real displacement of the corresponding anchor. Similarly, according to the above process, the horizontal displacements of other pontoons and the horizontal displacement of the center of the floating foundation platform can be calculated; Finally, through the calculated horizontal displacements of all pontoons and the horizontal displacement of the center of the floating foundation platform, the real displacements of all anchors can be truly reflected, so as to accurately evaluate the safety of the floating wind turbine.

2. A displacement detection method for a floating wind turbine according to claim 1, It is characterized in that: The weight is a circular weight.

3. A displacement detection method for a floating wind turbine according to claim 1, It is characterized in that: The floating foundation platform is formed with three support arms.

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