Offshore wind turbine pile foundation anti-scouring system and installation method thereof

Abstract

The invention relates to the technical field of offshore wind power engineering, and discloses an offshore wind turbine pile foundation anti-scour system and a mounting method thereof.The offshore wind turbine pile foundation anti-scour system comprises a fixing frame and spoilers, the fixing frame comprises a fixing ring and a supporting beam, the supporting beam is fixedly assembled on the side, away from a pile foundation, of the fixing ring, and the spoilers are annularly distributed in the circumferential direction of the fixing ring; a flow passing hole is formed between every two adjacent spoilers, one end of each spoiler is connected with the supporting beam to form a fixed end, the other end of each spoiler forms an overhanging end, and the spoilers are flexible pieces so that the overhanging ends can swing with the supporting beam as a base point. The fixing frame and the spoiler can be integrally arranged on the pile foundation in a sleeving mode after being assembled on the land, the number of installation procedures is small, the laying effect of the area nearby the pile foundation is guaranteed, and reliability is high. After the pile foundation is sleeved with the fixing ring, the spoiler covers the periphery of the pile foundation, the flowing direction of water flow is changed through the overflowing holes, meanwhile, the spoiler is a flexible part and can swing up and down and left and right within a small range under the action of the water flow, and the purposes of spoiling and scouring resistance are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore wind power engineering, and in particular to an offshore wind turbine pile foundation anti-scour system and an installation method thereof. Background Art

[0002] As the most widely used foundation form in the field of offshore wind power engineering, the single pile foundation is currently the main form of fixed single pile wind turbine foundation in wind farms within a water depth of 30m. However, due to the large diameter of the single pile foundation, the ocean current encounters the obstruction of the pile column and causes disturbance, the flow velocity around the pile column increases, and scour pits are easily formed. Scour pits weaken the pile-soil effect near the mud surface, which is not conducive to the stability of the single pile foundation.

[0003] In order to ensure the safety of the single pile foundation structure, anti-scouring measures are required for protection. At present, the most common practice in engineering is to lay gravity sand blankets, that is, to use a crane ship to spread sand blankets of different sizes to the seabed, and use the sand blankets for ballasting to prevent the lower soil from being eroded by waves and currents; its disadvantage is that the operation is relatively difficult, especially at the root of the steel pipe pile, the laying work is difficult to meet the design requirements, and the actual anti-scouring effect is greatly reduced. Another conventional practice is the riprap method, that is, using riprap to form an anti-filtration layer around the pile foundation to prevent the surface soil from being eroded; but riprap can easily damage the main structure of the wind turbine, and it is difficult to recycle the riprap, which affects the environment, and maintenance is required in the later stage of riprap, and there is a risk of secondary scouring.

[0004] For example, the authorization announcement number is CN205822279U, a marine structure anti-scour system, including a covering layer and a ballast. The covering layer is composed of a flexible material with permeable holes. The covering layer is laid flat, and the ballast is distributed evenly or in a certain pattern above the covering layer. The density of the ballast is greater than the density of seawater.

[0005] However, the above-mentioned anti-scour system has many installation steps during construction, and the ballast at the edge lacks constraints and may be lifted or shifted under the action of waves and currents, resulting in the loss of protection of the underlying cover layer, and poor reliability and resistance to extreme environments. Summary of the invention

[0006] The purpose of the present invention is to provide an offshore wind turbine pile foundation anti-scour system to solve the problem of multiple installation procedures and poor reliability of the anti-scour system in the prior art; the present invention also provides an anti-scour system construction method.

[0007] In order to achieve the above-mentioned purpose, the present invention provides an offshore wind turbine pile foundation anti-scour system, including a fixing frame and a spoiler, the fixing frame includes a fixing ring and a support beam, the fixing ring is used to be mounted on the pile foundation, the support beam is fixedly assembled on the side of the fixing ring away from the pile foundation, the spoiler has multiple groups, each of the spoilers is distributed in a ring shape along the circumference of the fixing ring, and a flow hole for water to pass through is provided between two adjacent spoilers, one end of the spoiler is connected to the support beam to form a fixed end, and the other end forms a cantilevered end, and the spoiler is a flexible member so that the cantilevered end swings with the support beam as a base point.

[0008] Preferably, the spoilers are radially distributed with the fixing ring as the center, the size of the fixing end is larger than that of the overhanging end, the end surfaces of two adjacent spoilers close to each other are concave curved surfaces, and the space between the curved surfaces of two adjacent spoilers forms the flow hole.

[0009] Preferably, the curved surface is an arc surface, and the interval between the fixed ends of two adjacent spoilers is greater than the interval between the overhanging ends.

[0010] Preferably, the spoiler is a rubber piece.

[0011] Preferably, a dimension of the spoiler along the radial direction of the fixing ring is greater than or equal to a radius of the pile foundation.

[0012] Preferably, the support beam comprises a plurality of beam bodies, each of the beam bodies is radially distributed with the fixing ring as the center, the beam bodies correspond one-to-one to the spoilers, and the fixed end of a single spoiler is fixedly assembled on a single beam body.

[0013] Preferably, the fixed end of the spoiler is supported and covered on the beam body, and the fixed end is bonded and fixed to the beam body.

[0014] Preferably, the spoiler also has a cable hole for a submarine cable to pass through.

[0015] Preferably, the fixing frame further comprises a corbel, the corbel is used for being fixedly assembled on the pile foundation, the fixing ring support is arranged on the corbel, and a gasket is further provided between the fixing ring and the corbel.

[0016] The present invention also provides a method for constructing an anti-scour system, which is used for the offshore wind turbine pile foundation anti-scour system described in any one of the above technical solutions, and comprises the following steps:

[0017] S1, assembling the fixing ring and the supporting beam of the fixing frame on land, and fixing and assembling the spoiler and the supporting beam to form a whole;

[0018] S2, after the pile foundation is driven and before the cage is constructed, the overall structure assembled in step S1 is inserted from the top of the pile foundation and sunk to a set height;

[0019] S3, setting a corbel on the pile foundation, installing a gasket on the corbel, and the overall structure in step S2 is supported on the gasket on the upper side of the corbel;

[0020] S4, pull the submarine cable underwater through the cable hole on the spoiler, the submarine cable enters the submarine cable opening on the pile foundation, and the submarine cable is tied and fixed to the support beam.

[0021] Compared with the prior art, the offshore wind turbine pile foundation anti-scour system and installation method of the embodiment of the present invention have the following beneficial effects: during assembly, the fixing frame and the spoiler can be integrally mounted on the pile foundation after being assembled on land, with fewer installation steps, ensuring the laying effect in the area near the pile foundation and strong reliability; after the fixing ring is mounted on the pile foundation, the spoiler covers the periphery of the pile foundation, and the flow hole changes the flow direction of the water flow, ensuring a suitable water inlet flow rate and ensuring the stability of the spoiler; at the same time, since the fixed end of the spoiler is connected to the support beam, the cantilevered end is a free structure, and the spoiler is a flexible part, the spoiler can swing in a small range up, down, left, and right under the action of the water flow, changing the flow direction of the water flow, thereby achieving the purpose of spoiler and anti-scour. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the assembly structure of the offshore wind turbine pile foundation anti-scour system and the pile foundation of the present invention;

[0023] Figure 2 yes Figure 1 A cross-sectional diagram of an offshore wind turbine pile foundation anti-scour system;

[0024] Figure 3 yes Figure 1 Schematic diagram of the assembly cross section of the fixing frame and pile foundation of the offshore wind turbine pile foundation anti-scour system;

[0025] Figure 4 It is a schematic diagram of the assembly nodes of the corbel, the fixing ring and the support beam of the offshore wind turbine pile foundation anti-scour system.

[0026] In the figure, 1, fixing ring, 2, supporting beam, 21, beam body, 3, spoiler, 31, fixed end, 32, overhanging end, 33, flow hole, 34, cable hole, 4, corbel, 41, gasket, 5, pile foundation, 6, submarine cable. DETAILED DESCRIPTION

[0027] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0028] A preferred embodiment of an offshore wind turbine pile foundation anti-scour system of the present invention is as follows: Figures 1 to 4 As shown, the offshore wind turbine pile foundation anti-scour system includes a fixing frame and a spoiler 3. The fixing frame is used to be fixedly assembled on the pile foundation 5 to provide assembly support for the spoiler 3. The spoiler 3 is used to change the flow direction of water flow and protect the area around the pile foundation 5.

[0029] The fixing frame includes a fixing ring 1 and a support beam 2, and the fixing ring 1 is used to be mounted on the pile foundation 5 and connected and assembled with the pile foundation 5. The fixing ring 1 is a circular structure, and its inner diameter is about 5 cm larger than the outer diameter of the pile foundation 5, so as to facilitate the fixing ring 1 to be mounted on the outer side of the pile foundation 5. In this embodiment, the fixing ring 1 is made of steel, and the cross-section of the fixing ring 1 is a box beam structure to ensure the overall strength of the fixing ring 1.

[0030] The support beam 2 is fixedly assembled on the side of the fixing ring 1 away from the pile foundation 5, that is, the support beam 2 is connected to the outside of the fixing ring 1. In this embodiment, the support beam 2 is a steel beam, and the support beam 2 is welded and fixed to the fixing ring 1. The support beam 2 extends in the radial direction of the fixing ring 1, and the support beam 2 provides an assembly station for the spoiler 3, supports the spoiler 3, and ensures the overall strength of the fixing frame.

[0031] There are multiple groups of spoilers 3, each spoiler 3 is evenly spaced in a ring shape along the circumference of the fixing ring 1, and each spoiler 3 forms a ring in a 360-degree direction. There is a flow hole 33 between two adjacent spoilers 3, and the flow hole 33 is used to allow water to pass through the spoiler 3, disrupting the water flow that originally impacts the soil near the column foundation, and playing a protective role.

[0032] One end of the spoiler 3 is connected to the support beam 2 to form a fixed end 31, and the other end forms a cantilever end 32, that is, only the fixed end 31 of the spoiler 3 is fixed, and the cantilever end 32 of the spoiler 3 is a free structure. The spoiler 3 is a flexible member. When impacted by water flow, the cantilever end 32 of the spoiler 3 swings with the fixed end 31 connected to the support beam 2 as a base point, changing the flow direction of the water flow, playing a role in spoiling the flow and protecting the pile foundation 5. In this embodiment, there are eight spoilers 3, and the eight spoilers 3 are evenly distributed around the fixing ring 1.

[0033] When assembling the offshore wind turbine pile foundation anti-scour system, the fixing frame and the spoiler 3 can be integrally mounted on the pile foundation 5 after being assembled on land, with fewer installation steps, ensuring the laying effect in the area near the pile foundation 5 and strong reliability; after the fixing ring 1 is mounted on the pile foundation 5, the spoiler 3 covers the periphery of the pile foundation 5, and the flow hole 33 changes the flow direction of the water flow, ensuring a suitable water inlet flow rate and ensuring the stability of the spoiler 3. At the same time, since the fixed end 31 of the spoiler 3 is connected to the support beam 2, the overhanging end 32 is a free structure, and the spoiler 3 is a flexible part, the spoiler 3 can swing in a small range up, down, left, and right under the action of the water flow, changing the flow direction of the water flow, and achieving the purpose of spoiling and anti-scour.

[0034] Preferably, the spoilers 3 are radially distributed with the fixing ring 1 as the center, the size of the fixing end 31 is larger than the size of the overhanging end 32, the end surfaces of two adjacent spoilers 3 close to each other are concave curved surfaces, and the space between the curved surfaces of two adjacent spoilers 3 forms a flow hole 33.

[0035] The spoilers 3 are radially distributed, which can protect the pile foundation 5 in the entire circumference. The size of the fixed end 31 is larger than that of the cantilever end 32, which increases the mass of the cantilever end 32, increases the swing amplitude, and improves the spoiler effect. In addition, the end faces of the two spoilers 3 close to each other are curved surfaces, that is, the contour of the spoiler 3 is arc-shaped, which can optimize the flow of fluid between the spoilers 3, avoid excessive local flow velocity, reduce water flow resistance, and guide the direction of water flow to avoid the mud and sand around the pile foundation 5 being carried away by the water flow, thereby reducing the pressure on the lower part of the spoiler 3.

[0036] Preferably, the curved surface is an arc surface, and the interval between the fixed ends 31 of two adjacent spoilers 3 is greater than the interval between the overhanging ends 32 .

[0037] The curved surface is an arc surface, which is convenient for processing. The interval between the fixed ends 31 is greater than the interval between the overhanging ends 32. Water can flow through the fixed ends 31 of the spoiler 3, reducing water flow resistance. In this embodiment, the overhanging ends 32 of two adjacent spoilers 3 fit each other.

[0038] Preferably, the spoiler 3 is a rubber member.

[0039] The spoiler 3 of the rubber member has sufficient strength and quality while maintaining flexibility, thereby ensuring the stability of the spoiler 3 .

[0040] Preferably, the dimension of the spoiler 3 along the radial direction of the fixing ring 1 is greater than or equal to the radius of the pile foundation 5 .

[0041] When water flows over the pile foundation 5, the scouring range of the soil around the pile foundation 5 is within the range of twice the diameter of the pile foundation 5. Therefore, the radial dimension of the spoiler 3 is greater than or equal to the radius of the pile foundation 5, and the diameter of the ring formed by the spoiler 3 is at least twice the diameter, thereby ensuring the protection of the soil within the scouring range of the water flow.

[0042] Preferably, the support beam 2 includes a plurality of beam bodies 21 , each beam body 21 is radially distributed with the fixing ring 1 as the center, the beam bodies 21 correspond one-to-one to the spoilers 3 , and the fixed end 31 of a single spoiler 3 is fixedly assembled on a single beam body 21 .

[0043] The support beam 2 is formed by a plurality of beam bodies 21, which reduces the overall mass of the support beam 2, simplifies the structure of the support beam 2, and is easy to build, process, and install. The beam bodies 21 correspond to the spoilers 3 one by one, ensuring that the fixed end 31 of each spoiler 3 is assembled and fixed to the beam body 21. In this embodiment, the length of the beam body 21 along the radial direction of the fixing ring 1 is 1m, which strengthens the overall rigidity of the beam body 21.

[0044] Preferably, the fixed end 31 of the spoiler 3 is supported and covered on the beam body 21 , and the fixed end 31 is bonded and fixed to the beam body 21 .

[0045] The fixed end 31 of the spoiler 3 is supported and covered on the beam body 21, so that the spoiler 3, the beam body 21 and the fixing ring 1 are in an up-and-down structure, which increases the fixed contact area between the spoiler 3 and the beam body 21, and makes the bonding between the fixing plate and the beam body 21 more stable. In this embodiment, the fixed end 31 of the spoiler 3 is also connected to the beam body 21 by rivets to fasten the spoiler 3.

[0046] Preferably, the spoiler 3 also has a cable hole 34 for the submarine cable 6 to pass through.

[0047] A cable hole 34 is provided on the spoiler 3 for the submarine cable 6 to pass through, which can facilitate the passage of the submarine cable 6. The spoiler 3 is used to limit the position of the submarine cable 6, reduce the swing of the submarine cable 6, and provide protection for the submarine cable 6. In this embodiment, the submarine cable 6 can be tied and connected with the support beam 2 after passing through the cable hole 34, which helps to reduce the hanging length of the submarine cable 6, reduce the vortex-induced vibration of the submarine cable 6, and ensure the normal operation of the submarine cable 6. In this embodiment, the aperture of the cable hole 34 is larger than the diameter of the submarine cable 6 by about 1-2 mm, which can facilitate the passage of the submarine cable 6.

[0048] Preferably, the fixing frame further comprises a corbel 4 , which is used for being fixedly assembled on the pile foundation 5 , the fixing ring 1 is supported and arranged on the corbel 4 , and a gasket 41 is further provided between the fixing ring 1 and the corbel 4 .

[0049] The corbel 4 can be welded and fixed on the pile foundation 5. The corbel 4 is used to support the fixing ring 1 and the support beam 2. The fixing ring 1 is supported on the corbel 4, so that the fixing ring 1 can sit directly on the corbel 4 without being fixed to the pile foundation 5, which simplifies the assembly form of the fixing ring 1. A gasket 41 is arranged between the fixing ring 1 and the corbel 4. Through the deformation of the gasket 41, the fixing ring 1 can be tightly connected to the pile foundation 5. In this embodiment, the gasket 41 is made of rubber, and the corbel 4 is assembled on the pile foundation 5 at a position 1m below the original opening of the submarine cable 6.

[0050] The present invention also provides a preferred embodiment of a construction method for an anti-scour system, which is used for an offshore wind turbine pile foundation anti-scour system of any of the above embodiments, and comprises the following steps:

[0051] S1, assembling the fixing ring 1 and the supporting beam 2 of the fixing frame on land, and fixing and assembling the spoiler 3 and the supporting beam 2 to form a whole.

[0052] The assembly of the fixing ring 1 and the support beam 2 can be carried out on land, and the underwater construction only requires the submarine cable 6 to pass through the spoiler 3, which is simple to install and manufacture, and is convenient for controlling installation risks and installation quality. In this step, the coordinates are determined with the center of the pile foundation 5 as the reference point, and the fixing ring 1 and the support beam 2 are assembled.

[0053] S2, after the pile foundation 5 is driven and before the cage construction, the whole structure assembled in step S1 is inserted from the top of the pile foundation 5 and sunk to a set height.

[0054] The fixing ring 1 and the supporting beam 2 are directly mounted on the pile foundation 5 as a whole. Before installing the cage, the fixing ring 1 and the supporting beam 2 can be installed using the same equipment as that used for installing the cage.

[0055] S3, a corbel 4 is arranged on the pile foundation 5, and a gasket 41 is installed on the corbel 4. The whole structure in step S2 is supported on the gasket 41 on the upper side of the corbel 4.

[0056] The corbel 4 is fixed to the pile foundation 5 by welding, and the fixing ring 1 is located on the corbel 4 , which simplifies the assembly method of the fixing ring 1 , the pile foundation 5 and the corbel 4 .

[0057] S4, pulling the submarine cable 6 underwater through the cable hole 34 on the spoiler 3, the submarine cable 6 enters the submarine cable 6 opening on the pile foundation 5, and the submarine cable 6 is tied and fixed to the support beam 2.

[0058] After passing through the cable hole 34 , the submarine cable 6 is tied and fixed to the support beam 2 , which reduces the shaking of the submarine cable 6 , helps to reduce the hanging length of the submarine cable 6 , reduces the vortex-induced vibration of the submarine cable 6 , and ensures the normal operation of the submarine cable 6 .

[0059] In summary, the embodiment of the present invention provides an offshore wind turbine pile foundation anti-scour system and an installation method thereof. During assembly, the fixing frame and the spoiler can be integrally mounted on the pile foundation after being assembled on land. The installation process is small, the laying effect in the area near the pile foundation is ensured, and the reliability is strong. After the fixing ring is mounted on the pile foundation, the spoiler covers the periphery of the pile foundation, and the flow hole changes the flow direction of the water flow, ensuring a suitable water inlet flow rate and ensuring the stability of the spoiler. At the same time, since the fixed end of the spoiler is connected to the support beam, the cantilevered end is a free structure, and the spoiler is a flexible part, the spoiler can swing in a small range up, down, left, and right under the action of the water flow, thereby changing the flow direction of the water flow and achieving the purpose of spoiler and anti-scour.

[0060] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. An offshore wind turbine pile foundation anti-scour system, characterized in that: The invention comprises a fixing frame and a spoiler (3), wherein the fixing frame comprises a fixing ring (1) and a supporting beam (2), wherein the fixing ring (1) is used for being mounted on a pile foundation (5), and the supporting beam (2) is fixedly mounted on a side of the fixing ring (1) away from the pile foundation (5). The spoiler (3) comprises a plurality of groups, and each of the spoilers (3) is distributed in a ring shape along the circumference of the fixing ring (1), and a flow hole (33) for water flow to pass through is provided between two adjacent spoilers (3). One end of the spoiler (3) is connected to the supporting beam (2) to form a fixed end (31), and the other end forms a cantilever end (32). The spoiler (3) is a flexible member so that the cantilever end (32) can swing with the supporting beam (2) as a base point.

2. The offshore wind turbine pile foundation anti-scour system according to claim 1, characterized in that: The spoilers (3) are radially distributed with the fixed ring (1) as the center, the size of the fixed end (31) is larger than the size of the overhanging end (32), the end surfaces of two adjacent spoilers (3) close to each other are concave curved surfaces, and the space between the curved surfaces of two adjacent spoilers (3) forms the flow hole (33).

3. The offshore wind turbine pile foundation anti-scour system according to claim 2, characterized in that: The curved surface is an arc surface, and the interval between the fixed ends (31) of two adjacent spoilers (3) is greater than the interval between the overhanging ends (32).

4. The offshore wind turbine pile foundation anti-scour system according to any one of claims 1 to 3, characterized in that: The spoiler (3) is a rubber piece.

5. The offshore wind turbine pile foundation anti-scour system according to any one of claims 1 to 3, characterized in that: The dimension of the spoiler (3) along the radial direction of the fixing ring (1) is greater than or equal to the radius of the pile foundation (5).

6. The offshore wind turbine pile foundation anti-scour system according to any one of claims 1 to 3, characterized in that: The support beam (2) comprises a plurality of beam bodies (21), each of the beam bodies (21) being radially distributed with the fixing ring (1) as the center, the beam bodies (21) corresponding to the spoilers (3) one by one, and the fixed end (31) of a single spoiler (3) being fixedly mounted on a single beam body (21).

7. The offshore wind turbine pile foundation anti-scour system according to claim 6, characterized in that: The fixed end (31) of the spoiler (3) is supported and covered on the beam body (21), and the fixed end (31) is bonded and fixed to the beam body (21).

8. The offshore wind turbine pile foundation anti-scour system according to any one of claims 1 to 3, characterized in that: The spoiler (3) also has a cable hole (34) for a submarine cable to pass through.

9. The offshore wind turbine pile foundation anti-scour system according to any one of claims 1 to 3, characterized in that: The fixing frame also includes a corbel (4), the corbel (4) being used for being fixedly assembled on the pile foundation (5), the fixing ring (1) being supported and arranged on the corbel (4), and a gasket (41) being provided between the fixing ring (1) and the corbel (4).

10. A method for constructing an anti-scour system, used for the offshore wind turbine pile foundation anti-scour system according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, assembling the fixing ring (1) and the supporting beam (2) of the fixing frame on land, and fixing and assembling the spoiler (3) and the supporting beam (2) to form a whole; S2, after the pile foundation (5) is driven and before the cage construction, the whole structure assembled in step S1 is inserted from the top of the pile foundation (5) and sunk to a set height; S3, arranging a corbel (4) on the pile foundation (5), installing a gasket (41) on the corbel (4), and the whole structure in step S2 is supported on the gasket (41) on the upper side of the corbel (4); S4, pulling the submarine cable underwater through the cable hole (34) on the spoiler (3), the submarine cable enters the submarine cable opening on the pile foundation (5), and the submarine cable is tied and fixed to the support beam (2).

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