A scour protection device for offshore wind turbine foundations and its installation method

Abstract

This invention relates to an anti-scour device and its installation method for offshore wind turbine foundations. The anti-scour device includes an anti-scour net embedded in a riprap layer surrounding the wind turbine foundation. The anti-scour net comprises several tire assemblies and several ropes. The tire assemblies are spaced apart, and adjacent tire assemblies are connected by ropes. Each tire assembly includes a large tire and a small tire arranged concentrically, with the small tire located inside the large tire. The large and small tires are connected and fixed together by connectors. By installing the anti-scour net, composed of tire assemblies and ropes, around the wind turbine foundation, the riprap layer is secured. Because the tire assemblies are embedded in the riprap layer, the scour effect of ocean currents on the riprap layer is reduced, preventing displacement of the riprap and the formation of craters, thus ensuring the stability of the wind turbine foundation.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power equipment technology, and in particular to an anti-scouring device for offshore wind power pile foundations and a method for installing the anti-scouring device. Background Technology

[0002] With the continuous development of offshore wind power technology, the installed capacity of offshore wind turbines has been increasing year by year. (Reference) Figure 1 As shown, an offshore wind turbine mainly consists of a base 1′, a mast 2′, wind turbine blades, and a generator set. The base 1′ and mast 2′ form the wind turbine foundation. The wind turbine blades and generator set are installed on the mast 2′ of the wind turbine foundation. The base 1′ is installed on the seabed, and a layer of riprap 3′ is buried on the base 1′. The bottom of the wind turbine foundation is buried within the riprap layer 3′ to improve the stability of the wind turbine foundation installation. However, the presence of the wind turbine foundation affects the surrounding flow field, forming strong turbulence and vortices. Under the local scouring effect of the surrounding ocean currents, craters 4′ appear in the riprap layer 3′. As the number and size of the craters 4′ increase, the riprap layer 3′ is severely eroded, threatening the overall stability of the wind turbine foundation installation. Summary of the Invention

[0003] The purpose of this invention is to provide an anti-scour device and an installation method for offshore wind turbine pile foundations, which has high reliability, can improve the installation stability of wind turbine pile foundations, and has high installation efficiency.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A scour protection device for offshore wind turbine foundations is provided, comprising a circular scour protection net for embedding in a riprap layer surrounding the wind turbine foundation. The scour protection net includes several tire assemblies and several ropes. The tire assemblies are spaced apart and connected to adjacent tire assemblies by the ropes. Each tire assembly includes a large tire and a small tire arranged concentrically, with the small tire located inside the large tire. The large tire and the small tire are connected and fixed together by connectors.

[0006] Furthermore, the connector includes a screw, a nut, and a mounting ring. One end of the screw is connected and fixed to the mounting ring, and the other end is used to install the nut. The screw passes through the large tire and the small tire, with the mounting ring located on the outer ring side of the large tire and the nut located on the inner ring side of the small tire. The mounting ring is used to connect with the rope.

[0007] Furthermore, a locking hook is provided at the end of the rope, and the locking hook is engaged with the mounting ring.

[0008] Furthermore, along the circumferential direction of the anti-erosion net, two adjacent tire assemblies are connected by the rope;

[0009] Along the radial direction of the anti-erosion net, two adjacent tire assemblies are connected by the rope.

[0010] Furthermore, some of the small tires are filled with concrete.

[0011] Furthermore, it also includes a positioning ring, which is sleeved on the wind turbine pile foundation, and one side of the inner ring of the anti-scour net is connected and fixed to the positioning ring.

[0012] Furthermore, the plurality of tire assemblies are divided into multiple tire groups, each tire group comprising multiple tire assemblies, the multiple tire groups being radially spaced along the wind turbine pile foundation, and the multiple tire assemblies in each tire group being circumferentially spaced along the wind turbine pile foundation.

[0013] Furthermore, the rope is made of steel wire, iron chain, or nylon rope.

[0014] A method for installing an anti-scour device is also provided, for installing an anti-scour device on an offshore wind turbine foundation, comprising the following steps:

[0015] Step S10: Divide the scour protection net into multiple mesh blocks along the circumferential direction of the wind turbine pile foundation, and complete the assembly of each mesh block on land;

[0016] Step S20: Using multiple vessels, transport multiple mesh blocks to the sea surface. The multiple vessels are evenly arranged around the perimeter of the wind turbine pile foundation to connect and fix two adjacent mesh blocks.

[0017] Step S30: First, sink one end of the inner ring of the anti-scouring net into the seabed along the height direction of the wind turbine pile foundation, and then drive the vessel to move in a direction away from the wind turbine pile foundation so that the anti-scouring net sinks into the seabed from one end of the inner ring to one end of the outer ring.

[0018] Step S40: Stack riprap on the anti-scouring net to form a riprap layer, and embed the anti-scouring net within the riprap layer.

[0019] Furthermore, a pull rope is provided, one end of which is connected to the vessel, and the other end is detachably connected to one end of the outer ring of the scour protection net. During the sinking of the outer ring of the scour protection net, the pull rope applies a pulling force to the scour protection net away from the wind turbine pile foundation. When the outer ring of the scour protection net approaches the seabed, the pull rope is disconnected from the scour protection net.

[0020] The advantages of this invention compared to the prior art are:

[0021] This invention discloses an anti-scour device and its installation method for offshore wind turbine foundations. An anti-scour net, composed of tire components and ropes, is installed around the wind turbine foundation to secure the riprap layer. Because the tire components are embedded in the riprap layer, they weaken the scouring effect of ocean currents, preventing displacement of the riprap and the formation of craters, thus ensuring the stability of the wind turbine foundation. By assembling multiple tire components and ropes into a mesh structure, the anti-scour net can be directly submerged from the sea surface to the seabed for installation, avoiding underwater diving and improving installation efficiency. Furthermore, the tire components, including concentrically arranged large and small tires, help reduce the porosity of the entire anti-scour net, improving its anti-scour performance and ensuring high reliability. Attached Figure Description

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This is a schematic diagram of the installation of wind turbine pile foundations in existing technology.

[0024] Figure 2 This is a schematic diagram of an anti-scouring device for offshore wind power pile foundations according to an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of a tire assembly according to an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram illustrating the installation process of the anti-scouring device for offshore wind power pile foundations according to an embodiment of the present invention.

[0027] Figure 1 middle:

[0028] 1′, base; 2′, pole; 3′, riprap layer; 4′, crater.

[0029] Figures 2 to 4 middle:

[0030] 1. Anti-erosion net; 11. Tire assembly; 111. Large tire; 112. Small tire; 113. Screw; 114. Mounting ring; 115. Nut; 12. Rope; 2. Positioning ring; 3. Base; 4. Rod; 5. Mounting groove; 6. Boat; 7. Pull rope. Detailed Implementation

[0031] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0032] like Figures 2 to 4As shown, this invention provides an anti-scouring device (hereinafter referred to as the anti-scouring device) for offshore wind turbine foundations, which is used in conjunction with the wind turbine foundation to improve the installation stability of the wind turbine foundation. The wind turbine foundation is used to install wind turbine blades and generator sets, etc. The wind turbine foundation is installed on the seabed and includes a base 3 and a rod 4. The base 3 is connected and fixed to the bottom end of the rod 4, and the wind turbine blades are installed at the top end of the rod 4. An installation groove 5 is provided on the seabed, and the base 3 is installed in the installation groove 5. The installation groove 5 is filled with riprap to form a riprap layer. The bottom of the wind turbine foundation is buried in the riprap layer, and the riprap layer applies pressure to the wind turbine foundation to ensure the installation stability of the wind turbine foundation.

[0033] The scour protection device includes a scour protection net 1, which has a circular ring structure and surrounds the pole 4 of the wind turbine foundation. The scour protection net 1 is fitted around the perimeter of the pole 4, with its outer ring extending away from the pole 4, so that the entire scour protection net 1 is laid flat on the seabed. The scour protection net 1 includes several tire assemblies 11 and several ropes 12. The tire assemblies 11 are spaced apart on the seabed surface, and their distribution can be rectangular, circular, or irregular. Adjacent tire assemblies 11 are connected by ropes 12 to form a mesh structure. After the scour protection net 1 is installed, riprap is backfilled around the wind turbine pile foundation to form a riprap layer. The riprap can fill the mesh of the scour protection net 1, and the top surface of the riprap layer is not lower than the top surface of the scour protection net 1, so that the scour protection net 1 is embedded in the riprap layer. During operation, because the riprap layer is embedded with tire components 11, the tire components 11 can weaken the scouring effect of the ocean current on the riprap layer, prevent the riprap from shifting under the scouring of seawater and causing craters, thereby achieving the scour protection effect of the riprap layer and ensuring the stability of the wind turbine pile foundation.

[0034] The tire assembly 11 includes a large tire 111 and a small tire 112. The diameter of the large tire 111 is larger than the diameter of the small tire 112. The large tire 111 and the small tire 112 are concentrically arranged, with the small tire 112 located inside the large tire 111. The large tire 111 and the small tire 112 are connected and fixed together by a connector. It is understood that both the large tire 111 and the small tire 112 are recycled tires to reduce costs and improve waste utilization. By using the large tire 111 and the small tire 112 together to form the tire assembly 11, it is beneficial to reduce the porosity of the entire erosion control net 1, increase the volume ratio of the entire erosion control net 1 in the riprap layer, and improve the erosion control performance. The connector serves to install and fix the large tire 111 and the small tire 112. The connector includes a screw 113, a mounting ring 114, and a nut 115. One end of the screw 113 is connected to the mounting ring 114, and the other end is provided with a thread that mates with the nut 115. Nut 115 is threadedly connected to screw 113. During installation, screw 113 passes through both the large tire 111 and the small tire 112. One end of screw 113 with a mounting ring 114 abuts against the outer ring of the large tire 111, meaning the mounting ring 114 is located on the outer ring side of the large tire 111. Nut 115 abuts against the inner ring of the small tire 112, meaning the nut 115 is located on the inner ring side of the small tire 112. Multiple connectors are used, spaced apart along the circumference of the tire assembly 11. Alternatively, in other embodiments, a washer can be placed between nut 115 and small tire 112 to improve installation stability.

[0035] The mounting ring 114 is a metal ring structure used for connecting to the rope 12. Correspondingly, the end of the rope 12 is provided with a locking hook, which is used to hook onto the mounting ring 114 to connect the rope 12 to the tire assembly 11, making installation convenient. Of course, in other embodiments, the rope 12 can also be directly tied to the mounting ring 114. In this embodiment, the rope 12 is a steel wire, iron chain, or nylon rope.

[0036] Optionally, refer to Figure 2 As shown, adjacent tire assemblies 11 are connected by ropes 12 along the circumferential direction of the scour protection net 1. Also, adjacent tire assemblies 11 are connected by ropes 12 along the radial direction of the scour protection net 1. This structure allows the tire assemblies 11 to be restrained by tension in two mutually perpendicular directions, i.e., the tire assemblies 11 are subjected to tension in both the radial and circumferential directions of the scour protection net 1, preventing the tire assemblies 11 from moving due to seawater scouring. Correspondingly, several tire assemblies 11 are divided into multiple tire groups, each tire group comprising multiple tire assemblies 11. That is, the entire scour protection net 1 comprises multiple tire groups. The multiple tire groups are distributed radially at intervals along the wind turbine foundation, i.e., the multiple tire groups are distributed in a concentric circle pattern. The multiple tire assemblies 11 in each tire group are distributed at intervals along the circumferential direction of the wind turbine foundation.

[0037] Optionally, to increase the weight of the tire assembly 11 and prevent it from suspending or shifting in ocean currents, some of the smaller tires 112 of the tire assembly 11 are filled with concrete. This structure increases the weight of the tire assembly 11 and can promote the sinking of the entire anti-scour net 1 during installation. The number of concrete-filled lower tires 112 can be flexibly selected according to the specific buoyancy of the tire assembly 11.

[0038] Optionally, refer to Figure 4 As shown, the anti-scour device also includes a positioning ring 2. The positioning ring 2 has a circular structure and is fitted onto the pole 4 of the wind turbine foundation. One side of the inner ring of the anti-scour net 1 is connected and fixed to the positioning ring 2. Specifically, one side of the inner ring of the anti-scour net 1 is connected and fixed to the positioning ring 2 via a rope 12. The positioning ring 2 serves to position the anti-scour net 1 during installation.

[0039] Optionally, the anti-erosion device includes multiple layers of anti-erosion netting 1, which are stacked vertically. The number of layers of anti-erosion netting 1 can be adapted to the thickness of the riprap layer. When the riprap layer is thick, multiple layers of anti-erosion netting 1 can be used; when the riprap layer is thin, a single layer of anti-erosion netting 1 can be used. The purpose is to increase the number of tire components 11 distributed in the riprap layer and improve the anti-erosion effect.

[0040] A method for installing an anti-erosion device is also provided. This method includes the following steps:

[0041] Step S10: Along the circumference of the wind turbine foundation, the scour protection net 1 is divided into multiple mesh blocks, and the assembly of each mesh block is completed on land. Specifically, the scour protection net 1 can be divided into four to eight fan-shaped mesh blocks. First, the large tires 111 and the small tires 112 are assembled into tire assemblies 11 using connectors. Then, multiple tire assemblies 11 are connected by ropes 12 to form multiple mesh blocks.

[0042] Step S20: Multiple boats 6 are used to transport multiple net blocks to the sea surface. The number of boats 6 is the same as the number of net blocks, with each boat 6 carrying one net block. The multiple boats 6 are evenly arranged around the perimeter of the wind turbine foundation. Then, adjacent net blocks are connected and fixed. The assembly of adjacent net blocks is carried out on the sea surface. Specifically, the end of the rope 12 is equipped with a locking hook, which is used to hook the mounting ring 114 in the tire assembly 11, making the operation convenient.

[0043] Step S30: First, the inner ring of the scour net 1 is lowered into the seabed along the height direction of the wind turbine pile foundation. Then, the vessel 6 is driven to move in the direction away from the wind turbine pile foundation, so that the scour net 1 sinks into the seabed sequentially from the inner ring to the outer ring. Specifically, a positioning ring 2 is provided at the inner ring of the scour net 1. The positioning ring 2 is first fitted onto the pole 4, and then the inner ring of the scour net 1 is connected and fixed to the positioning ring 2 by a rope 12. The positioning ring 2 can sink along the height direction of the pole 4. It is understood that the tire assembly 11 has a large buoyancy, and the entire scour net 1 will float during the sinking process in the seawater, which will prevent the tire assembly 11 from sinking in the vertical direction, ultimately causing the scour net 1 to not be laid out flat. If the scour net 1 cannot be laid out flat, diving operations are required. When installing the scour protection net 1, the inner ring end of the net is first submerged into the seabed. Then, the vessel 6 moves away from the wind turbine piles, pulling the outer ring end of the net in the same direction, causing it to unfold outwards. During the sinking process, the net is pulled outwards by the vessel 6, promoting its flatness on the seabed. This method avoids the need for underwater installation due to the net's inability to unfold smoothly, and features high installation efficiency and ease of operation.

[0044] Step S40: After the anti-scouring net 1 is installed, pile up riprap on the anti-scouring net 1 to form a riprap layer, and embed the anti-scouring net 1 in the riprap layer.

[0045] Optionally, in step S30, a pull rope 7 is also provided. One end of the pull rope 7 is connected to the vessel 6, and the other end is detachably connected to one end of the outer ring of the scour protection net 1. The function of the pull rope 7 is to increase the movement distance of the vessel 6. During the sinking of the outer ring of the scour protection net 1, the scour protection net 1 is detached from the vessel 6. The pull rope 7 continues to apply a pulling force to the scour protection net 1 away from the wind turbine pile foundation, that is, the pull rope 7 continues to apply an outward pulling force to the scour protection net 1, so that the scour protection net 1 slowly sinks under the pulling force of the pull rope 7, which helps the scour protection net 1 to fully unfold. When the outer ring of the scour protection net 1 is close to the seabed, the pull rope 7 is disconnected from the scour protection net 1. At this time, the scour protection net 1 is fully unfolded and laid flat on the seabed.

[0046] Understandably, the installation method of this anti-scour device allows assembly and submersion to be carried out on land and sea, avoiding underwater construction, and features high installation efficiency and ease of operation.

[0047] The beneficial effects of this embodiment are as follows: By setting up an anti-scour net 1 composed of tire components 11 and ropes 12 around the wind turbine pile foundation, the riprap layer is fixed. Since the tire components 11 are embedded in the riprap layer, they can weaken the scouring effect of the ocean current on the riprap layer, preventing the riprap from shifting and creating craters, thus ensuring the stability of the wind turbine pile foundation. By forming a mesh structure with multiple tire components 11 and ropes 12, the anti-scour net 1 can be directly submerged from the sea surface to the seabed for installation, avoiding underwater diving and improving installation efficiency. Simultaneously, the tire components 11 include concentrically arranged large tires 111 and small tires 112, which helps reduce the porosity of the entire anti-scour net 1, improves its anti-scour performance, and has high reliability.

[0048] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A scour prevention device for offshore wind turbine foundation piles, characterized in that, The device includes a circular anti-scour net and a positioning ring. The anti-scour net is used to be embedded in the riprap layer around the wind turbine pile foundation. The anti-scour net includes several tire assemblies and several ropes. The tire assemblies are spaced apart and adjacent tire assemblies are connected by the ropes. Each tire assembly includes a large tire and a small tire arranged concentrically. The small tire is located inside the large tire. The large tire and the small tire are connected and fixed by a connector. The connector includes a screw, a nut, and a mounting ring. One end of the screw is connected and fixed to the mounting ring, and the other end is used to install the nut. The screw passes through the large tire and the small tire, with the mounting ring located on the outer ring side of the large tire and the nut located on the inner ring side of the small tire. The mounting ring is used to connect to the rope. The end of the rope is provided with a locking hook, which is engaged with the mounting ring; Along the circumferential direction of the anti-erosion net, two adjacent tire assemblies are connected by the rope; Along the radial direction of the anti-erosion net, two adjacent tire assemblies are connected by the rope; Some of the small tires were filled with concrete; The positioning ring is fitted onto the wind turbine pile foundation, and one side of the inner ring of the anti-scour net is connected and fixed to the positioning ring.

2. The anti-scouring device for offshore wind turbine pile foundations according to claim 1, characterized in that, The tire assemblies are divided into multiple tire groups, each tire group includes multiple tire assemblies, the multiple tire groups are distributed radially at intervals along the wind turbine pile foundation, and the multiple tire assemblies in each tire group are distributed circumferentially at intervals along the wind turbine pile foundation.

3. The anti-scouring device for offshore wind turbine pile foundations according to claim 1, characterized in that, The rope is made of steel wire, iron chain, or nylon rope.

4. A method for installing an anti-scour device, used for installing the anti-scour device for offshore wind turbine pile foundations as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Step S10: Divide the scour protection net into multiple mesh blocks along the circumferential direction of the wind turbine pile foundation, and complete the assembly of each mesh block on land; Step S20: Using multiple vessels, transport multiple mesh blocks to the sea surface. The multiple vessels are evenly arranged around the perimeter of the wind turbine pile foundation to connect and fix two adjacent mesh blocks. Step S30: First, sink one end of the inner ring of the anti-scouring net into the seabed along the height direction of the wind turbine pile foundation, and then drive the vessel to move in a direction away from the wind turbine pile foundation so that the anti-scouring net sinks into the seabed from one end of the inner ring to one end of the outer ring. Step S40: Stack riprap on the anti-scouring net to form a riprap layer, and embed the anti-scouring net within the riprap layer.

5. The method for installing the anti-erosion device according to claim 4, characterized in that, A pull rope is provided, one end of which is connected to the vessel, and the other end is detachably connected to one end of the outer ring of the scour protection net. During the sinking of one end of the outer ring of the scour protection net, the pull rope is used to apply a pulling force to the scour protection net away from the wind turbine pile foundation. When one end of the outer ring of the scour protection net approaches the seabed, the pull rope is disconnected from the scour protection net.

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