CN109736343B

CN109736343B - Offshore wind power foundation, installation method thereof and wind generating set

Info

Publication number: CN109736343B
Application number: CN201910156169.9A
Authority: CN
Inventors: 方建丰; 李荣富; 王婷婷; 张新刚; 翟恩地
Original assignee: Jiangsu Goldwind Science and Technology Co Ltd
Current assignee: Jiangsu Goldwind Science and Technology Co Ltd
Priority date: 2019-03-01
Filing date: 2019-03-01
Publication date: 2023-03-21
Anticipated expiration: 2039-03-01
Also published as: CN109736343A

Abstract

The invention provides an offshore wind power foundation, an installation method thereof and a wind generating set. Offshore wind power foundation includes: the floating box is internally provided with a cavity, and the upper surface of the floating box is provided with a through hole communicated with the cavity; the suction cylinder is arranged on the lower surface of the buoyancy tank; and the jacket is arranged on the upper surface of the buoyancy tank. The offshore wind power foundation provided by the invention has self-floating capacity, can be self-installed, can save installation time and reduce wave load.

Description

Offshore wind power foundation, installation method thereof and wind generating set

Technical Field

The invention relates to the technical field of offshore wind power generation, in particular to an offshore wind power foundation, an installation method thereof and a wind generating set.

Background

An offshore wind generating set generally comprises a tower head (a wind wheel and a cabin), a tower frame and a foundation, wherein the foundation of an offshore wind farm is crucial to the safety of the whole machine.

The common foundation types of the offshore wind generating set comprise a single-pile foundation, a jacket foundation, a gravity type foundation and a suction cylinder foundation. The main legs and the struts of the jacket foundation are small in diameter, small in wave force and high in rigidity, but the installation construction of the jacket foundation needs piling and underwater grouting, a piling hammer, underwater grouting equipment, a diver or an ROV and related ship resource installation are needed, so that the construction period and the construction installation cost are high, if bedrock with shallow buried depth is encountered, rock-socketed pile construction needs to be carried out, the construction period is greatly increased, the construction cost is very high, and the construction time is also short in sea areas with short construction window periods, such as Fujian and Guangdong.

Gravity type basis need not the pile, and adopts precast concrete, and the cost is lower, but needs comparatively level and smooth, and the better rock stratum of lithology or closely knit sand layer are as the ground, and the bearing layer depth of burial is more shallow, for example, the bearing layer depth of burial is more shallow, the relatively level and smooth guangdong of ground, the fujian sea area, if the bearing layer depth of burial is more dark or unevenness, then need to dredge and ground leveling, the construction cycle is long, and the working costs is high.

The suction cylinder foundation realizes floating, dragging and self-installation by utilizing a negative pressure principle, but is suitable for dense sandy soil with higher soil rigidity.

Therefore, there is a need to provide a foundation for an offshore wind energy plant that overcomes the above problems.

Disclosure of Invention

The invention aims to provide an offshore wind power foundation, an installation method thereof and a wind generating set, wherein the offshore wind power foundation has self-floating capacity, can be self-installed, saves installation time and can reduce wave load.

According to an aspect of the present invention, there is provided an offshore wind farm, the offshore wind farm comprising: the floating box is internally provided with a cavity, and the upper surface of the floating box is provided with a through hole communicated with the cavity; the suction cylinder is arranged on the lower surface of the buoyancy tank; and the jacket is arranged on the upper surface of the buoyancy tank. The offshore wind power foundation provided by the invention has self-floating capacity, can be self-installed, saves installation time and can reduce wave load.

Alternatively, the lower end of the suction tube may be open, and the area of the cross section of the suction tube may be gradually reduced from bottom to top. Through the design, the side friction resistance between the wall of the suction tube and the soil can be increased, and the uplift bearing capacity can be improved.

Alternatively, the suction canister may comprise shear keys arranged circumferentially on the inner and/or outer wall of the suction canister. Through the design, the side friction between the cylinder wall and the soil can be further increased, and the uplift bearing capacity is improved.

Alternatively, the suction drum may include a plurality of drum pieces connected to each other in a circumferential direction of the suction drum.

Alternatively, each of the plurality of web segments may be a profiled web segment. By such a design, the local stiffness can be improved, thereby improving the ability of resisting in-plane and out-of-plane buckling when the suction tube is penetrated.

Alternatively, the cross-section of each web may be arcuate or dog-legged.

Alternatively, the suction cartridge may be disposed in the center of the lower surface of the buoyancy tank, and/or the suction cartridge may be disposed around the center of the lower surface of the buoyancy tank. By such a design, structural stability can be improved.

Alternatively, the jacket may be disposed in the center of the upper surface of the pontoon. By such a design, structural stability can be improved.

According to another aspect of the present invention, there is provided an installation method of an offshore wind power foundation, the installation method comprising: dragging the offshore wind power foundation to an installation site; pumping the slurry into a buoyancy tank; when the suction barrel is contacted with the mud surface, the suction barrel is vacuumized; after the suction cylinder is filled to the designed depth, continuously pumping the slurry until the buoyancy tank is full; and a riprap is arranged at the contact position of the buoyancy tank and the mud surface.

According to another aspect of the invention, a wind park is provided, comprising an offshore wind farm as above.

According to the offshore wind power foundation, the wave load can be reduced, and the power load of the integral supporting structure can be reduced.

According to the offshore wind power foundation, the foundation can be sunk and poured by using the negative pressure sinking and pouring principle, the construction and installation time can be greatly shortened, and meanwhile, the construction ship resources such as a pile hammer, a pile driving ship and the like can be reduced.

According to the offshore wind power foundation provided by the embodiment of the invention, the whole foundation can be designed into a self-floating type by utilizing the buoyancy tank, so that ship resources such as barges or landing-leg ships can be saved, and the construction and installation cost is greatly reduced.

According to the offshore wind power foundation provided by the embodiment of the invention, the cylinder sheet of the suction cylinder is set into the special-shaped cylinder sheet, the suction cylinder is basically in a circular truncated cone shape, and the shear keys are arranged, so that the offshore wind power foundation provided by the invention can be suitable for soft clay areas with thick overburden layers, and the application of the traditional suction cylinder foundation is expanded.

Drawings

FIG. 1 is a perspective view of an offshore wind farm according to an embodiment of the present invention;

FIG. 2 is a perspective view of another perspective of the offshore wind farm of FIG. 1;

FIG. 3 is a perspective view of the offshore wind power foundation suction canister of FIG. 1;

FIG. 4 is a front view of the suction cartridge of FIG. 3;

FIG. 5 is a perspective view of a portion of the suction cartridge of FIG. 3;

FIG. 6 is a top view of the offshore wind farm buoyancy tank of FIG. 1;

FIG. 7 is a perspective view of an offshore wind farm according to another embodiment of the present invention;

FIG. 8 is a perspective view of an offshore wind farm according to yet another embodiment of the present invention;

fig. 9 to 12 are sectional views of modified examples of a suction tube according to an embodiment of the present invention;

fig. 13 to 17 are schematic diagrams of arrangements of buoyancy tanks and suction canisters according to embodiments of the present invention;

FIG. 18 is a schematic view of the offshore wind farm shown in FIG. 1 in a condition during towing;

fig. 19 is a schematic view of an installation state of the offshore wind power foundation shown in fig. 1.

Detailed Description

Hereinafter, an offshore wind power foundation according to an embodiment of the present invention will be described in detail with reference to fig. 1 to 19.

As shown in fig. 1 and 2, an offshore wind farm according to an embodiment of the present invention may include: the floating box 10 is provided with a cavity inside, and a through hole 11 communicated with the cavity is formed in the upper surface 10a of the floating box 10; a suction cylinder 20, the suction cylinder 20 being disposed on the lower surface 10b of the buoyancy tank 10; a jacket 30, the jacket 30 being disposed on an upper surface of the pontoon 10.

According to an embodiment of the present invention, the offshore wind power foundation may include a buoyancy tank 10, and the buoyancy tank 10 may have a box structure, and a cavity is formed inside the buoyancy tank 10. As shown in fig. 1, the float 10 may have an upper surface 10a, a lower surface 10b, and a side surface 10c connecting the upper surface 10a and the lower surface 10b to each other. The upper surface 10a and the lower surface 10b may be parallel to each other and have substantially the same size, and the side surface 10c may be connected between the upper surface 10a and the lower surface 10b to define a cavity between the upper surface 10a, the lower surface 10b, and the side surface 10c.

In order to increase the rigidity of the buoyancy tank 10 according to an embodiment of the present invention, criss-cross support plates (not shown) may be provided in the buoyancy tank 10. As shown in fig. 1, the buoyancy tank 10 may have a prism shape (e.g., a hexagonal prism shape), however, the present invention is not limited thereto. For example, as shown in fig. 7, the buoyancy tank 10 may have a cylindrical shape, or as shown in fig. 8, the buoyancy tank 10 may have a tetragonal shape (e.g., a square shape).

In addition, according to an embodiment of the present invention, a through hole 11 communicating with the cavity is provided on the upper surface of the float chamber 10, and by providing the through hole 11, liquid and gas in the cavity can be discharged from the through hole 11 when slurry is poured into the cavity in the float chamber 10. As shown in fig. 6, the through-holes 11 are arranged in a triangle on the upper surface of the buoyancy tank 10, for example, the through-holes 11 shown in fig. 6 are arranged in four triangles. By arranging the through holes 11 in a triangular shape, the liquid and gas in the buoyancy tank 10 can be uniformly discharged.

According to an embodiment of the present invention, mooring dolphins 12 may be provided on the upper surface of the pontoon 10, for example, two sets of mooring dolphins 12 may be symmetrically provided on both sides of the upper surface of the pontoon 10, so that bi-directional marine floating can be achieved. In the transportation state, the buoyancy tank 10 is kept in an empty bin state to provide buoyancy for the offshore wind power foundation so as to keep the offshore wind power foundation in a floating state, and the offshore wind power foundation is towed to an installation site by a tug boat through the bollards 12 and the mooring ropes 13 tied to the bollards 12.

According to an embodiment of the present invention, the offshore wind power foundation may further include a suction tube 20 disposed on a lower surface of the pontoon 10. As shown in fig. 3, an upper end of the suction tube 20 may be coupled to a lower surface of the buoyancy chamber 10, and a lower end of the suction tube 20 may be opened, so that when the suction tube 20 is filled with soil 3 (shown in fig. 19), the soil 3 may be introduced into the suction tube 20 from the lower end of the suction tube 20, thereby fixing the suction tube 20. In addition, the upper end of the suction tube 20 may be closed by the buoyancy tank 10, so that the suction tube 20 may enclose a tube shape having both ends opened.

According to an embodiment of the present invention, the area of the cross-section of the suction cartridge 20 may gradually decrease from bottom to top. According to the embodiment of the present invention, by making the area of the cross section of the suction cylinder 20 gradually decrease from bottom to top (in the shape of an inverted cup), when the suction cylinder 20 is filled into the soil 3 (as shown in fig. 19), the side frictional resistance between the cylinder wall of the suction cylinder 20 and the soil can be increased, and thus the uplift resistance can be improved.

Specifically, as shown in fig. 3, the suction tube 20 may have a substantially circular truncated cone shape. As shown in fig. 3 to 5, the suction cartridge 20 may include a plurality of cartridges 21 connected to each other in a circumferential direction of the suction cartridge 20. Each segment 21 may be a profiled segment to increase local stiffness and increase the pull-out bearing capacity of the suction tube, thereby increasing the resistance of the suction tube 20 to in-plane and out-of-plane buckling as it penetrates. Wherein, the irregular cylindrical sheet means that the cylindrical sheet 21 is not a regular rectangular shape.

For example, the cross-section of the profile cylinder sheet may be an arc shape as shown in fig. 9 to 11, or a zigzag shape as shown in fig. 12, but the present invention is not limited thereto so as to facilitate the manufacturing. The plurality of segments 21 may be welded to one another to form the suction cartridge 20. In addition, although an example in which the plurality of barrel pieces 21 are equal in size to each other is shown in fig. 3, the present invention is not limited thereto.

Although the structure in which the suction tube 20 includes the plurality of tube pieces 21 is described above, the present invention is not limited thereto, and the suction tube 20 may be formed as an integrated structure by casting.

In addition, according to an embodiment of the present invention, as shown in fig. 13 to 17, the suction cartridge 20 may be disposed at the center of the bottom surface of the buoyancy tank 10 and/or disposed around the center of the bottom surface of the buoyancy tank 10 to ensure uniform force.

In fig. 13, one suction cylinder 20 is provided, and the suction cylinder 20 is provided at the center of the bottom surface of the pontoon 10. In fig. 14, four suction cartridges 20 are provided, and the suction cartridges 20 are disposed around the center of the bottom surface of the pontoon 10. In fig. 15, five suction cartridges 20 are provided, and the suction cartridges 20 are disposed around the center of the bottom surface of the buoyancy tank 10. In fig. 16, five suction cartridges 20 are provided, wherein one suction cartridge 20 is disposed at the center of the bottom surface of the pontoon 10, and the other four suction cartridges 20 are disposed around the center of the bottom surface of the pontoon 10. In fig. 17, six suction cartridges 20 are provided, and the suction cartridges 20 are disposed around the center of the bottom surface of the pontoon 10. When a plurality of suction cartridges 20 are provided, the plurality of suction cartridges 20 may be identical to each other in size, but the present invention is not limited thereto. In addition, it should be understood that the arrangement form of the suction tube according to the embodiment of the present invention is not limited to the examples shown in fig. 13 to 17.

According to an embodiment of the present invention, as shown in fig. 5, the suction canister 20 may include shear keys 22, and the shear keys 22 are disposed on an inner wall and/or an outer wall of the suction canister 20 in a circumferential direction. Specifically, as shown in fig. 3, the shear key 22 refers to a protruding rib protruding inward from an inner wall of the suction canister 20 by a predetermined distance or protruding outward from an outer wall of the suction canister 20 by a predetermined distance.

According to an embodiment of the present invention, a plurality of shear keys 22 may be provided on the inner wall and/or the outer wall of the suction tube 20 in the circumferential direction, and the plurality of shear keys 22 may be uniformly provided from top to bottom as shown in fig. 3 to 5. However, the present invention is not limited thereto. In addition, it is illustrated in fig. 3 to 5 that the shear key 22 is provided on both the inner wall and the outer wall of the suction tube 20, but the present invention is not limited thereto, and the shear key 22 may be provided only on the inner wall or the outer wall of the suction tube 20.

According to the embodiment of the invention, by arranging the shear keys 22, when the suction barrel 20 is poured into the soil 3 (as shown in fig. 19), the side friction between the barrel wall and the soil can be increased, and the pulling resistance bearing capacity is improved.

As described above, according to the suction tube 20 of the embodiment of the present invention, by configuring the tube sheet 21 as a special-shaped tube sheet, making the suction tube 20 substantially in a circular truncated cone shape, and configuring the shear keys 22, the offshore wind power foundation of the present invention can be applied to a soft clay area with a thick overburden, and thus the application of the conventional suction tube foundation can be expanded. Moreover, because the pulling-resistant bearing capacity of the suction tube 20 can be improved, compared with the traditional suction tube 20, the size of the suction tube 20 can be effectively reduced, and the foundation construction cost can be reduced.

The offshore wind farm according to embodiments of the present invention may further comprise a jacket 30 disposed on the upper surface of the pontoon 10. According to an embodiment of the present invention, the axial directions of the suction tube, the buoyancy tank, and the jacket may be identical to each other to secure structural stability.

According to an embodiment of the present invention, the jacket 30 may include a plurality of main legs 31 and struts 32 disposed between the main legs 31 to connect the main legs 31 to each other. Although four main legs 31 are shown in fig. 1 and 2 and a specific arrangement of the main legs 31 and the struts 32 is shown, the present invention is not limited thereto, but the number of the main legs 31 and the arrangement of the main legs 31 and the struts 32 may be variously modified. According to an embodiment of the invention, the jacket 30 may further comprise a transition section 33 arranged on top of the main legs 31 and the stay 32 for connecting a tower of a wind turbine. The transition section 33 may include a base outer platform 33a, a main drum 33b provided on the base outer platform 33a, and a diagonal support 33c provided on the base outer platform 33a to support the main drum 33 b.

It should be understood that although a specific structure of the jacket 30 is illustrated above, the present invention is not limited thereto, and the jacket 30 according to the present invention may have any structure known in the art as long as it can be disposed on the upper surface of the pontoon 10.

According to the embodiment of the invention, the main legs 31 and the support rods 32 of the jacket 30 are small in size and are small waterplane structures, so that the bearing capacity of the jacket is small, the wave load can be reduced, the structural dynamic deformation response of the support structure can be reduced, and the dynamic load of the whole support structure can be reduced. Meanwhile, the jacket 30 has strong structural rigidity, can improve the first-order frequency of the whole machine, and is very suitable for geological conditions with weak surface soil rigidity.

Hereinafter, an installation method of the offshore wind power foundation illustrated in fig. 1 will be described with reference to fig. 18 and 19.

As shown in fig. 18, in the transportation state, the buoyancy tank 10 is kept empty to provide buoyancy to the offshore wind power foundation so that the offshore wind power foundation is kept floating on the sea level 1, and is towed to the installation site by the tug boat through the bollard 12 and the cable 13 tied to the bollard 12.

When installed, mud is pumped into the buoyancy tank 10 through the grout line 5 (the grout line 5 may be disposed to be attached to the steel pipe wall of the main leg 31, however, the present invention is not limited thereto), and as the mud is pumped, the weight of the entire foundation increases and the foundation sinks. When the suction cylinder 20 contacts the mud surface 2, liquid and gas in the suction cylinder 20 are pumped out through a vacuum pumping device, a negative pressure state is realized in the suction cylinder 20, and the suction cylinder 20 is filled into the soil 3 by using the negative pressure. After the suction tube 20 is filled to the designed depth, the slurry is continuously pumped until the buoyancy tank 10 is full, the liquid and gas discharged during slurry filling can be discharged through the through hole 11, and whether the slurry is full can be checked through the through hole 11. After the foundation is installed, a riprap 4 may be placed in the contact position between the pontoon 10 and the mud surface 2 to provide anti-scour protection to the pontoon 10.

A wind park according to an embodiment of the invention may comprise an offshore wind farm as described above. In addition, a wind power plant according to an embodiment of the invention may further comprise a tower, which may be connected to the transition piece 33 of the jacket 30 by means of, for example, a flange.

As described above, according to the embodiments of the present invention, the upper structure of the offshore wind power foundation can adopt a jacket structure form, and the main legs and the struts of the jacket have small sizes and are small waterplane structures, so that the jacket can bear small wave loads, the wave loads can be reduced, and the structural dynamic deformation response of the support structure can be reduced, thereby reducing the dynamic loads of the whole support structure. Meanwhile, the jacket has stronger structural rigidity, can improve the first-order frequency of the whole machine, and is very suitable for geological conditions with weaker surface soil rigidity.

According to the embodiment of the invention, the lower structure of the offshore wind power foundation adopts the suction cylinder foundation, and the foundation is sunk and poured by utilizing the negative pressure sinking and pouring principle, so that the construction and installation time can be greatly shortened, and meanwhile, the construction ship resources such as a piling hammer, a piling ship and the like can be reduced compared with the traditional long pile piling construction.

In addition, according to an embodiment of the present invention, the intermediate structure of the offshore wind power foundation may employ a buoyancy tank. The whole foundation can be designed into a self-floating type by utilizing the buoyancy tank, can be directly towed to an aircraft site by the tugboat, and can save ship resources such as barges or landing-leg ships and the like compared with the traditional foundation type, thereby greatly reducing the construction and installation cost. In addition, after the foundation is poured into the designed soil layer, slurry is pumped into the space in the buoyancy tank, and the bearing capacity and the anti-sliding stability of the foundation are improved by utilizing the gravity of the slurry.

In addition, according to the embodiment of the invention, the cylinder sheet of the suction cylinder is set into the special-shaped cylinder sheet, the suction cylinder is made to be in a circular truncated cone shape basically, and the shear keys are arranged, so that the offshore wind power foundation can be suitable for soft clay areas with thick overburden layers, and the application of the traditional suction cylinder foundation is expanded. In addition, the size of the suction tube can be effectively reduced, and the construction cost of foundation engineering can be reduced compared with the traditional suction tube.

Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims

1. An offshore wind farm foundation, comprising:

a buoyancy tank (10) having a cavity formed inside the buoyancy tank (10), the cavity being enclosed by an upper surface (10 a), a lower surface (10 b) and a side surface (10 c) connecting the outer periphery of the upper surface (10 a) and the outer periphery of the lower surface (10 b) to each other, the upper surface (10 a) of the buoyancy tank (10) being provided with a through hole (11) communicating with the cavity;

a suction tube (20), wherein the suction tube (20) is arranged in the center of the lower surface (10 b) of the buoyancy tank (10), and/or the suction tube (20) is arranged around the center of the lower surface (10 b) of the buoyancy tank (10), the suction tube (20) and the cavity are overlapped in the vertical direction, the lower end of the suction tube (20) is open, and the upper end of the suction tube (20) is closed by the buoyancy tank (10);

a jacket (30), the jacket (30) being disposed on the upper surface (10 a) of the pontoon (10).

2. Offshore wind farm according to claim 1, characterized in that the cross-section of the suction canister (20) decreases gradually in area from bottom to top.

3. Offshore wind farm according to claim 1 or 2, characterized in that the suction canister (20) comprises shear keys (22) arranged in circumferential direction on the inner and/or outer wall of the suction canister (20).

4. Offshore wind farm according to claim 1 or 2, characterized in that the suction canister (20) comprises a plurality of canister segments (21) connected to each other in the circumferential direction of the suction canister (20).

5. Offshore wind foundation according to claim 4, characterized in that each of said drum segments (21) of said plurality of drum segments (21) is a profiled drum segment.

6. Offshore wind farm according to claim 4, characterized in that each of said blades (21) has an arc or dog-leg shaped cross section.

7. Offshore wind farm according to claim 1, characterized in that the jacket (30) is arranged centrally on the upper surface (10 a) of the pontoon (10).

8. Method for installing an offshore wind farm according to any of the claims 1 to 7, characterized in that it comprises:

towing the offshore wind power foundation to an installation site;

pumping a slurry into the buoyancy tank (10);

when the suction barrel (20) is in contact with the mud surface (2), vacuumizing the suction barrel (20);

when the suction cylinder (20) is filled to the designed depth, slurry is continuously pumped until the buoyancy tank (10) is filled;

and a riprap (4) is arranged at the contact position of the buoyancy tank (10) and the mud surface (2).

9. Wind park according to any of claims 1 to 7, characterized in that it comprises an offshore wind power foundation.