Offshore fixed type wind turbine foundation wave dissipation device and construction method thereof

Abstract

The application discloses a wave-absorbing device for offshore fixed wind turbine foundation and a construction method thereof. The device comprises support rods, rotating pins, wave-absorbing plates, floating buoys and wave-absorbing water bags. The support rods are radially arranged along the circumference of the offshore fixed wind turbine foundation and are rotatably connected to the offshore fixed wind turbine foundation through the rotating pins, so that the support rods can rotate around the offshore fixed wind turbine foundation with the change of the sea level. The wave-absorbing plates are arranged between two support rods. The application realizes wave energy dissipation by means of the inclined wave-absorbing plates, destroys the wave shape, consumes the horizontal energy of the waves, effectively reduces the force of the waves on the foundation structure and the fatigue load caused by the wave co-frequency, improves the application range of the overall frequency of the fixed foundation, enhances the control effect of the horizontal displacement of the support structure, and improves the economy of the offshore wind turbine set.

Description

Technical Field

[0001] This invention relates to the technical field of offshore fixed wind turbine foundations, and in particular to a wave-damping device for offshore fixed wind turbine foundations and its construction method. Background Technology

[0002] Offshore wind turbine foundations can be categorized into gravity foundations, monopile foundations, jacket foundations, pile cap foundations, and suction cylinder foundations. As a high-cantilever structure, the offshore wind turbine support structure not only bears the wind load transmitted by the upper blades but also resists the external forces exerted on the structure by waves and currents near the water surface. The larger the diameter of the foundation's circular pipe, the greater the wave and current forces acting on the foundation structure. Furthermore, due to the wide period range of offshore wind-generated waves (from 3s to 35s), the natural frequency of the entire wind turbine support structure inevitably resonates within a certain range of the wave period, leading to increased fatigue damage to the foundation and making the structure prone to fatigue damage or even wave resonance failure. In extreme sea conditions, waves have a significant impact on the wind turbine support structure, requiring sufficiently large foundation dimensions and rigidity, resulting in increased foundation usage and higher engineering costs. With the application of long-bladed, large-megawatt turbines, the combined external loads from wind and waves are increasing, drastically increasing the cost and usage of support structures for commonly used foundation types, impacting the economic viability of offshore wind farms. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and propose a wave-dissipating device for offshore fixed wind turbine foundations and its construction method. By using inclined wave-dissipating plates, wave climbing energy dissipation is achieved, the waveform is disrupted, and the horizontal energy of the waves is consumed. This effectively reduces the force of waves on the foundation structure and reduces the fatigue load caused by wave resonance, improves the overall frequency applicability range of the fixed foundation, reduces the engineering quantity of the support structure, enhances the control effect of the horizontal displacement of the support structure, and improves the economic efficiency of offshore wind turbines.

[0004] The objective of this invention is achieved through the following technical solution: a wave-damping device for a fixed offshore wind turbine foundation, comprising support rods, rotating pins, wave-damping plates, buoys, and wave-damping water bags; the support rods are arranged radially around the outer periphery of the fixed offshore wind turbine foundation and are rotatably connected to the fixed offshore wind turbine foundation via rotating pins, enabling them to rotate around the fixed offshore wind turbine foundation as the sea level changes; the buoys are installed at the center of the bottom of the support rods; the wave-damping water bags are installed at the free ends of the support rods; and the wave-damping plates are disposed between two support rods, ultimately achieving wave climbing and energy dissipation through the inclined wave-damping plates.

[0005] Furthermore, the supporting rods are circular rods, and multiple supporting rods are arranged at equal intervals and angles around the circumference of the offshore fixed wind turbine foundation.

[0006] Furthermore, the wave-damping plate has multiple holes, which are either square or round, to reduce the impact force of waves.

[0007] Furthermore, the support rods are connected by crisscrossing connecting reinforcements, forming multiple wave-damping plate mounting positions, in which the wave-damping plates are fixed.

[0008] Furthermore, the free end of the support rod is connected to a ballast weight via a rope, causing the support rod to be angled downwards as a whole.

[0009] Furthermore, the wave-damping plate is a single-layer wave-damping plate or a multi-layer wave-damping plate, and it is arc-shaped or flat.

[0010] Furthermore, the wave-damping plate comprises multiple small plates, which are spliced ​​together into a whole by ropes.

[0011] Furthermore, the pontoon is a square or rectangular plastic sealed pontoon.

[0012] Furthermore, the wave-damping water bag is a long, round or square wave-damping water bag, and the wave-damping water bag is also distributed and installed between the support rod and the wave-damping plate.

[0013] A construction method for the wave-damping device based on the above-mentioned offshore fixed wind turbine foundation includes the following steps:

[0014] S1. Confirm the installation height position on the offshore fixed wind turbine foundation, which should be 0.5m to 1m above the high tide level, and install rotating pins on the offshore fixed wind turbine foundation;

[0015] S2. Install the wave-damping device in modules. In the dock area, fix the buoys and wave-damping water bags to the support rods in sequence, and then connect the ballast weight to the free end of the support rods through ropes.

[0016] S3. Assemble the wave-damping plate between the support members. The wave-damping plate is composed of a series of small plates spliced ​​together and connected by ropes to form a whole wave-damping plate between the support members. Then install the connecting reinforcement.

[0017] S4. Using a maintenance vessel, transport the wave-damping device module to the offshore fixed wind turbine site for on-site installation. First, connect and fix the support rods to the rotating pins on the offshore fixed wind turbine foundation. After the connection is completed, connect and fix the wave-damping plate to the support rods. Complete the overall splicing in sequence to assemble a complete wave-damping device.

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

[0019] 1. This invention effectively reduces the direct force of waves on the supporting structure by applying a wave-damping device to the foundation near the water surface, optimizes the size of the supporting structure near the water surface, reduces the wave force, reduces the weight of the foundation structure, saves on the amount of structural engineering materials used in the foundation, and reduces the cost of the foundation.

[0020] 2. This invention can reduce the fatigue force of waves on the wind turbine support structure, reduce the resonance effect between waves and the support structure, and reduce the fatigue load of waves on the support structure. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the wave-damping device for a fixed offshore wind turbine foundation.

[0022] Figure 2 for Figure 1 A structural sectional view taken along section line AA.

[0023] Figure 3 This is a schematic diagram of the wave damping plate. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments.

[0025] Example 1

[0026] See Figures 1 to 3 As shown, the offshore fixed wind turbine foundation wave-damping device provided in this embodiment includes a support rod 5, a rotating pin 4, a wave-damping plate 8, a float 6, and a wave-damping water bag 7;

[0027] The support rod 5 has multiple radially arranged around the offshore fixed wind turbine foundation 3 and is rotatably connected to the offshore fixed wind turbine foundation 3 through rotating pins 4. It can rotate around the offshore fixed wind turbine foundation 3 as the sea level changes. The wave-damping plate 8 is set between two support rods 5. The float 6 is installed at the center of the bottom of the support rod 5. The wave-damping water bag 7 is installed at the free end of the support rod 5.

[0028] Among them, the support rod 5 is a circular rod. The support rods are arranged at the same distance and angle around the circumference of the fixed wind turbine foundation. The number of support rods is 3 to 6, and they are arranged at intervals of 60 degrees to 120 degrees.

[0029] The wave-damping plate 8 is a single-layer wave-damping plate or a multi-layer wave-damping plate, and has an arc shape or a flat plate shape. The wave-damping plate 8 is a spliced ​​plate or a whole plate. The spliced ​​plate is made up of multiple small plates connected by ropes. The holes on the wave-damping plate 8 are circular to reduce the impact force of the waves and convert the horizontal wave force into a force that rotates around the rotation axis, thereby reducing the horizontal force on the overall structure.

[0030] The float 6 is a plastic sealed float, fixed below the support rod 5. There are one or more sets of floats 6, and their shape is square or long and round, so that the entire wave-damping system floats near the water surface.

[0031] The free end of the support rod 5 is connected to the wave-damping water bag 7. The wave-damping water bag 7 is sealed and filled with water. The shape of the wave-damping water bag 7 is long and round or square. It is distributed and installed between the support rod 5 and the wave-damping plate 8. It works together with the wave-damping plate 8 to further reduce the wave force on the foundation structure.

[0032] The support member 5 is also provided with connecting reinforcement members 9 arranged in the horizontal and vertical directions, forming multiple wave-damping plate mounting positions. The wave-damping plate 8 is fixed in the wave-damping plate mounting positions. The connecting reinforcement members 9 provide connecting support for the wave-damping plate 8. The connecting reinforcement members 9 are rigid members or ropes.

[0033] The free end of the support rod 5 is connected to the ballast block 10 by a rope. The ballast block 10 is a concrete block. The ballast block makes the entire wave-damping device reach a certain immersion depth, reducing waves within a preset depth range.

[0034] Example 2

[0035] The construction method for the offshore fixed wind turbine foundation wave-damping device according to Embodiment 1 provided in this embodiment includes the following steps:

[0036] S1. Confirm the installation height position on the offshore fixed wind turbine foundation 3, which should be 0.5m to 1m above the high tide level, and arrange the rotating pin 4 on the offshore fixed wind turbine foundation.

[0037] S2. Install the wave-damping device in modules. In the dock area, fix the buoy 6 and the wave-damping water bag 7 to the support rod 5 in sequence, and then connect the ballast block 10 to the free end of the support rod 5 through ropes.

[0038] S3. Assemble the wave-damping plate 8 between the support rods 5. The wave-damping plate 8 is composed of a series of small plates spliced ​​together and connected by ropes in the middle to form the whole wave-damping plate 8 between the support rods 5. Then install the connecting reinforcement 9.

[0039] S4. Using a maintenance vessel, transport the wave-damping device module to the offshore fixed wind turbine site for on-site installation. First, connect and fix the support rod 5 to the rotating pin 4 on the offshore fixed wind turbine foundation 3. After the connection is completed, connect and fix the wave-damping plate 8 to the support rod 5. Complete the overall splicing in sequence to assemble a complete wave-damping device.

[0040] In summary, the wave-damping device of the present invention can achieve wave climbing and energy dissipation through inclined wave-damping plates. The wave drives its own movement to consume the horizontal energy of the wave, converting the horizontal force of the wave on the supporting structure into a vertical force. This effectively reduces the direct force of the wave on the foundation structure and reduces the fatigue load caused by wave resonance, improves the overall frequency applicability range of the fixed foundation, and reduces the engineering quantity of the supporting structure, thus having practical application value.

[0041] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, any changes made in accordance with the shape and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A wave-damping device for a fixed offshore wind turbine foundation, characterized in that: The system includes support rods, rotating pins, wave-damping plates, buoys, and wave-damping water bags. Multiple support rods are arranged radially around the outer periphery of the offshore fixed wind turbine foundation and are rotatably connected to the foundation via rotating pins, allowing them to rotate around the foundation as the sea level changes. The buoys are installed at the center of the bottom of the support rods, the wave-damping water bags are installed at the free ends of the support rods, and the wave-damping plates are positioned between two support rods, ultimately achieving wave climbing and energy dissipation through the inclined wave-damping plates. The support rods are circular, and multiple support rods are arranged at equal intervals and angles around the circumference of the offshore fixed wind turbine foundation. The wave-damping plates have multiple holes, which can be square or circular. One type of perforation is used to reduce the impact force of waves; the support rods are also connected by connecting reinforcements arranged laterally and longitudinally, forming multiple wave-damping plate mounting positions, in which the wave-damping plates are fixed; the free ends of the support rods are connected to ballast weights via ropes, making the support rods angled downwards; the wave-damping plates are single-layer or multi-layer wave-damping plates, and are arc-shaped or flat; the wave-damping plates include multiple small plates, which are spliced ​​together by ropes; the floats are square or rectangular plastic sealed floats; the wave-damping water bags are rectangular or square wave-damping water bags, which are also distributed and installed between the support rods and the wave-damping plates.

2. A construction method for a wave-damping device for a fixed offshore wind turbine foundation according to claim 1, characterized in that, Includes the following steps: S1. Confirm the installation height position on the offshore fixed wind turbine foundation, which should be 0.5m to 1m above the high tide level, and install rotating pins on the offshore fixed wind turbine foundation; S2. Install the wave-damping device in modules. In the dock area, fix the buoys and wave-damping water bags to the support rods in sequence, and then connect the ballast weight to the free end of the support rods through ropes. S3. Assemble the wave-damping plate between the support members. The wave-damping plate is composed of a series of small plates spliced ​​together and connected by ropes to form a whole wave-damping plate between the support members. Then install the connecting reinforcement. S4. Using a maintenance vessel, transport the wave-damping device module to the offshore fixed wind turbine site for on-site installation. First, connect and fix the support rods to the rotating pins on the offshore fixed wind turbine foundation. After the connection is completed, connect and fix the wave-damping plate to the support rods. Complete the overall splicing and assembly into a complete wave-damping device.

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