Anti-scour structure and method for offshore wind turbine pile foundation

Abstract

The present invention belongs to the field of marine engineering technology, and relates to an offshore wind turbine pile foundation anti-scour structure and method. The offshore wind turbine pile foundation anti-scour structure includes a pile foundation, a jacket and a plurality of wind turbine blades. The pile foundation is fixed on the seabed, and the jacket is sleeved on the outer periphery of the bottom end of the pile foundation. The peripheral wall of the jacket is provided with a plurality of positioning holes. The roots of the plurality of wind turbine blades are plugged and fixed in the corresponding positioning holes. The bottom of the wind turbine blades is in contact with the seabed surface, and the plurality of wind turbine blades are arranged at intervals on the circumference around the jacket. The offshore wind turbine pile foundation anti-scour structure of the present application can achieve the effect of disturbing the flow boundary layer by arranging a plurality of wind turbine blades, so that the kinetic energy of the bottom of the seabed surface is increased, the velocity difference of the upper and lower fluids is reduced, the kinetic energy difference is reduced, and then the horseshoe vortex strength is reduced, and finally the purpose of avoiding the formation of scour pits around the pile foundation is achieved. It does not require too much manpower and material resources, and only uses a jacket and a plurality of wind turbine blades.

Description

Technical Field

[0001] The invention belongs to the technical field of marine engineering, and in particular relates to an anti-scouring structure and method for pile foundation of an offshore wind turbine generator. Background Art

[0002] Offshore wind power generation technology rationally utilizes the abundant wind resources at sea, effectively increases the total amount of wind power generation, and enables the rapid development of wind power generation. The soil under some oceans is relatively soft and thin, and is easy to flow when washed by waves and ocean currents, resulting in scour pits around the pile foundations of offshore wind turbines. Scour pits endanger the stability of wind power generation equipment, so some anti-scour technologies (such as riprap, sand blankets, sand bags, etc.) and some anti-scour structures have been proposed. However, the existing anti-scour technology not only has the problem of difficulty in offshore operations, but also requires a lot of manpower and material resources to obtain the required consumables. For example, the riprap used for anti-scour requires the development of stone mountains. At the same time, some wind turbine blades that can no longer be used can only be treated by destroying them and then burying them, and they are not well recycled. Summary of the invention

[0003] The technical problem to be solved by the present invention is: in view of the problem that the existing offshore wind turbine pile foundation anti-scour technology requires a large amount of manpower and material resources, an offshore wind turbine pile foundation anti-scour structure and method are provided.

[0004] In order to solve the above technical problems, on the one hand, an embodiment of the present invention provides an offshore wind turbine pile foundation anti-scour structure, including a pile foundation, a jacket and a plurality of wind turbine blades, the pile foundation is fixed on the seabed, the jacket is arranged on the outer periphery of the bottom end of the pile foundation, a plurality of positioning holes are arranged on the peripheral wall of the jacket, the roots of the plurality of wind turbine blades are plugged and fixed in the corresponding positioning holes, the bottom of the wind turbine blades contacts the seabed surface, and the plurality of wind turbine blades are arranged at intervals on the circumference around the jacket.

[0005] Optionally, the wind turbine blades are wind turbine blades whose service life has expired or which can no longer be used for power generation in the wind farm.

[0006] Optionally, the jacket comprises a jacket body sleeved on the outer periphery of the bottom end of the pile foundation and a plurality of mounting columns spaced apart on the outer periphery of the jacket body, the mounting columns extending radially along the jacket body, and the positioning holes being inner holes of the mounting columns.

[0007] Optionally, a plurality of the mounting posts are arranged at equal intervals in the circumferential direction.

[0008] Optionally, the number of the fan blades is 3-6, and the jacket is provided with a corresponding number of the positioning holes.

[0009] Optionally, the diameter of the pile foundation is 6 m, and the root diameter of the wind turbine blade is 3.5 m.

[0010] Optionally, the maximum dimension of the tip of the wind turbine blade is 1.5 m.

[0011] According to the offshore wind turbine pile foundation anti-scour structure of the embodiment of the present invention, by setting a plurality of wind turbine blades, the effect of disturbing the flow boundary layer can be achieved, so that the kinetic energy of the bottom of the seabed surface is increased, the velocity difference of the upper and lower fluids is reduced, the kinetic energy difference is reduced, and the strength of the horseshoe vortex is reduced, and finally the purpose of avoiding the formation of scour pits around the pile foundation is achieved. The offshore wind turbine pile foundation anti-scour structure does not require too much manpower and material resources, and only uses a jacket and a plurality of wind turbine blades.

[0012] In addition, the wind turbine blades of some offshore wind turbines can still maintain a certain original three-dimensional structure after being damaged. Therefore, in this application, the wind turbine blades can be the wind turbine blades that have expired or can no longer be used for wind farm power generation due to force majeure. That is, idle wind turbine blades or waste wind turbine blades can be used as the main components of the offshore wind turbine pile foundation anti-scour structure, which can not only achieve the purpose of pile foundation anti-scour, but also can be used for a second time to reduce consumables.

[0013] On the other hand, an embodiment of the present invention provides an offshore wind turbine pile foundation anti-scour method based on the offshore wind turbine pile foundation anti-scour structure, comprising:

[0014] The jacket is placed on the outer periphery of the bottom end of the pile foundation;

[0015] The roots of a plurality of fan blades are inserted and fixed in the corresponding positioning holes on the jacket so that the bottoms of the fan blades are in contact with the seabed surface.

[0016] Optionally, it also includes:

[0017] The wind turbine blades which have expired or can no longer be used for power generation in the wind farm are removed from the wind turbines in the wind farm and used in the above-mentioned offshore wind turbine pile foundation anti-scour structure.

[0018] Optionally, the number of the fan blades is 3-6, and the jacket is provided with a corresponding number of the positioning holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of an offshore wind turbine pile foundation anti-scour structure provided by an embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of the connection between the fan blades and the jacket of the offshore wind turbine pile foundation anti-scour structure provided by one embodiment of the present invention;

[0021] Figure 3 This is the dimensional drawing of 10 fan blades installed in the jacket;

[0022] Figure 4 It is a schematic diagram of a boss with a certain slope formed by 10 fan blades.

[0023] The reference numerals in the specification are as follows:

[0024] 1. Wind turbine blades; 2. Jacket; 21. Jacket body; 22. Mounting column; 3. Positioning hole; 4. Pile foundation; 5. Seabed surface; 6. Boss. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] like Figure 1 and Figure 2 As shown, an offshore wind turbine pile foundation anti-scour structure provided by an embodiment of the present invention includes a pile foundation 4, a jacket 2 and a plurality of wind turbine blades 1, wherein the pile foundation 4 is fixed on the seabed, the jacket 2 is sleeved on the outer periphery of the bottom end of the pile foundation 4, a plurality of positioning holes 3 are provided on the peripheral wall of the jacket 2, the roots of the plurality of wind turbine blades 1 are plugged and fixed in the corresponding positioning holes 3, the bottom of the wind turbine blade 1 is in contact with the seabed surface 5, and the plurality of wind turbine blades 1 are arranged at intervals on the circumference around the jacket 2.

[0027] The root of the fan blade 1 is inserted and fixed in the corresponding positioning hole 3, which can be done by interference fitting, bolt connection, riveting and the like.

[0028] In one embodiment, the wind turbine blade 1 is a wind turbine blade that has expired or cannot be used for wind farm power generation due to force majeure. The wind turbine blade 1 may come from an offshore wind farm or a land wind farm.

[0029] In one embodiment, if Figure 2 As shown, the jacket 2 includes a jacket body 21 sleeved on the outer periphery of the bottom end of the pile foundation 4 and a plurality of mounting posts 22 spaced apart on the outer periphery of the jacket body 21, the mounting posts 22 extending radially along the jacket body 21, and the positioning holes 3 being inner holes of the mounting posts 22. Preferably, the plurality of mounting posts 22 are arranged at equal intervals in the circumferential direction.

[0030] Generally speaking, the pile foundation diameter is about 6m, and the root diameter of the wind turbine blade 1 connected to the jacket 2 is about 3.5m. Therefore, at this time, the number of wind turbine blades 1 and the number of positioning holes 3 in the offshore wind turbine pile foundation anti-scour structure are at most 3. When the root of the available idle (waste) wind turbine blade 1 is damaged, the tip of the wind turbine blade 1 can still be used in the pile foundation anti-scour structure of the present application after processing. However, its tip diameter is much smaller than the original root diameter. For example, Figure 1 The maximum size of the tip of the fan blade 1 is about 1.5 m, so in the extreme case, at most 10 blades can be installed. Figure 3 shown. Figure 3 Where d1 represents the pile diameter, d2 represents the maximum size of the tip of the wind turbine blade 1. When d1 is equal to 6m and d2 is equal to 1.5m, the circumference of the pile can be divided into 10 parts at most. In this way, the number of positioning holes 3 of the jacket 2 is also 10 at most, that is, in the extreme case, a maximum of 10 blades can be installed.

[0031] It should be pointed out that the more the number of wind turbine blades 1, the better the anti-scouring effect. If the number of wind turbine blades 1 is so large that they are closely connected, it can be considered that a boss 6 with a certain slope is arranged around the pile foundation 4 (such as Figure 3 As shown). The boss 6 only enlarges the bottom diameter of the pile foundation 4, and especially when its length is small, it cannot play a role in disrupting the formation of the scouring pit. At the same time, the more the number of wind turbine blades 1, the higher the corresponding investment cost, which will weaken the advantage of recycling the idle wind turbine blades 1 in this application.

[0032] Therefore, in the present application, the fan blades 1 are provided with 3-6 pieces, and the jacket 2 is provided with a corresponding number of positioning holes 3.

[0033] According to the offshore wind turbine pile foundation anti-scour structure of the embodiment of the present invention, by arranging a plurality of wind turbine blades 1, the effect of disturbing the flow boundary layer can be achieved, so that the kinetic energy of the bottom of the seabed surface 5 is increased, and the velocity difference of the upper and lower fluids is reduced ( Figure 1 The arrow V in the middle shows the change of velocity vector), the kinetic energy difference is reduced, and then the strength of the horseshoe vortex is reduced, and finally the purpose of avoiding the formation of scour pits around the pile foundation is achieved. The offshore wind turbine pile foundation anti-scour structure does not require too much manpower and material resources, and only uses a jacket 2 and a plurality of wind turbine blades 1.

[0034] In addition, the wind turbine blades 1 of some offshore wind turbines can still maintain a certain original three-dimensional structure after being damaged. Therefore, in this application, the wind turbine blades 1 can be wind turbine blades 1 that have expired or can no longer be used for wind farm power generation due to force majeure. That is, idle wind turbine blades 1 or waste wind turbine blades 1 can be used as the main components of the offshore wind turbine pile foundation anti-scouring structure, which can not only achieve the purpose of pile foundation anti-scouring, but also can reuse the wind turbine blades 1 to reduce consumables.

[0035] In addition, an embodiment of the present invention provides an offshore wind turbine pile foundation anti-scour method based on the offshore wind turbine pile foundation anti-scour structure of the above embodiment, comprising:

[0036] The jacket is sleeved on the periphery of the bottom of the pile foundation. For example, the jacket can be arranged in two parts, and after the two parts are attached to the periphery of the pile foundation, they are fixedly connected to form a complete jacket by bolts, riveting, etc.

[0037] The roots of a plurality of fan blades are inserted and fixed in the corresponding positioning holes on the jacket so that the bottoms of the fan blades are in contact with the seabed surface.

[0038] In one embodiment, the offshore wind turbine pile foundation anti-scour method of the present application further includes:

[0039] The wind turbine blades which have expired or can no longer be used for power generation in the wind farm are removed from the wind turbines in the wind farm and used in the above-mentioned offshore wind turbine pile foundation anti-scour structure.

[0040] The source of wind turbine blades can be offshore wind farms or onshore wind farms.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An offshore wind turbine pile foundation anti-scour structure, characterized in that: It comprises a pile foundation, a jacket and a plurality of wind turbine blades, wherein the pile foundation is fixed on the seabed, the jacket is sleeved on the outer periphery of the bottom end of the pile foundation, a plurality of positioning holes are arranged on the peripheral wall of the jacket, the roots of the plurality of wind turbine blades are plugged and fixed in the corresponding positioning holes, the bottom of the wind turbine blades contacts the seabed surface, and the plurality of wind turbine blades are arranged at intervals on the circumference around the jacket; The wind turbine blades are wind turbine blades whose service life has expired or can no longer be used for wind farm power generation; The jacket comprises a jacket body sleeved on the outer periphery of the bottom end of the pile foundation and a plurality of mounting columns spaced apart on the outer periphery of the jacket body, the mounting columns extending radially along the jacket body, and the positioning holes being inner holes of the mounting columns.

2. The offshore wind turbine pile foundation anti-scour structure according to claim 1, characterized in that: The plurality of mounting posts are arranged at equal intervals in the circumferential direction.

3. The offshore wind turbine pile foundation anti-scour structure according to claim 1, characterized in that: The fan blades are provided with 3-6 pieces, and the jacket is provided with a corresponding number of positioning holes.

4. The offshore wind turbine pile foundation anti-scour structure according to claim 1, characterized in that: The diameter of the pile foundation is 6m, and the root diameter of the wind turbine blade is 3.5m.

5. The offshore wind turbine pile foundation anti-scour structure according to claim 4, characterized in that: The maximum dimension of the tip of the fan blade is 1.5 m.

6. A method for preventing pile foundation scour of an offshore wind turbine based on the offshore wind turbine pile foundation scour prevention structure according to claim 1, characterized in that: include: The jacket is placed on the outer periphery of the bottom end of the pile foundation; The roots of a plurality of fan blades are inserted and fixed in the corresponding positioning holes on the jacket so that the bottoms of the fan blades are in contact with the seabed surface.

7. The offshore wind turbine pile foundation anti-scouring method according to claim 6, characterized in that: The fan blades are provided with 3-6 pieces, and the jacket is provided with a corresponding number of positioning holes.

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