Buoy structure suitable for floating type wind turbine generator foundation and foundation structure

Abstract

The invention discloses a buoy structure and a foundation structure suitable for a floating type wind turbine generator foundation, and the buoy structure comprises a distributed steel pipe frame which comprises a central steel pipe and peripheral steel pipes arranged around the central steel pipe; the end deck comprises an upper end deck and a lower end deck which are connected with the two ends of the distributed steel pipe frame respectively; the buoyancy module is made of glass fiber reinforced plastics and is formed by connecting a plurality of buoyancy units with a central steel pipe and a peripheral steel pipe in a layered manner, and each buoyancy unit is of a hollow watertight box body structure and is filled with a water pressure load or a solid pressure load; each buoyancy unit comprises a connecting pin connected with the central steel pipe, a through hole allowing the peripheral steel pipe to penetrate through and a skirt plate used for being connected with the adjacent buoyancy unit or the end deck, the connecting pins are arranged on the inner sides of the buoyancy units, the skirt plates are arranged on the outer sides of the buoyancy units, and connecting holes are formed in the skirt plates. The manufacturing and maintenance cost is effectively reduced, meanwhile, modular construction can be achieved, and the construction period is greatly shortened.

Description

Technical Field

[0001] The invention relates to offshore wind power generation technology, and in particular to a buoy structure and a foundation structure suitable for a floating wind turbine foundation. Background Art

[0002] Offshore wind power generation is an important component of clean energy. Studies have shown that for wind turbines installed in waters deeper than 60 meters, it is more economical to use floating foundation structures to support wind turbines than fixed foundations.

[0003] The foundation structure of a floating wind turbine is usually composed of multiple vertical or horizontal pontoons. As a key component of the floating foundation structure, the pontoon has an important impact on the economy, safety and reliability of the foundation structure. Traditional pontoons are made of pure steel, concrete or steel-concrete composite materials. Due to the high density of steel and concrete materials, it is necessary to increase the volume of the pontoon to provide sufficient buoyancy for the structure, resulting in an increase in material consumption and construction costs. In addition, the construction of a pure steel pontoon structure involves a lot of welding work, while the production of a concrete pontoon structure requires processes such as formwork, steel bar binding, pouring, and maintenance. The construction period is long, which is not conducive to large-scale construction. Summary of the invention

[0004] The technical problem to be solved by the present invention is that, in view of the high construction cost and long construction period of the buoy of the traditional floating wind turbine foundation structure, the present invention provides a buoy structure and foundation structure suitable for the foundation of a floating wind turbine, which can reduce the construction cost of the buoy and shorten the construction period.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A buoy structure suitable for a floating wind turbine foundation, comprising:

[0007] The distributed steel pipe frame is the main load-bearing component of the buoy, including a central steel pipe located in the center and peripheral steel pipes arranged around the central steel pipe. The central steel pipe and the peripheral steel pipe are arranged in parallel;

[0008] The end deck is a force transmission member at the end of the buoy, including an upper end deck and a lower end deck respectively connected to the two ends of the distributed steel pipe frame;

[0009] The buoyancy assembly is made of glass fiber reinforced plastic and is composed of a plurality of buoyancy units connected in layers to the central steel pipe and the peripheral steel pipes of the distributed steel pipe frame. Each buoyancy unit is a hollow watertight box structure filled with water ballast or solid ballast, and each buoyancy unit includes a connecting pin connected to the central steel pipe, a through hole for the peripheral steel pipe to pass through, and a skirt plate for connecting to an adjacent buoyancy unit or an end deck, wherein the connecting pin is arranged on the inner side of the buoyancy unit, the skirt plate is arranged on the outer side of the buoyancy unit, and the skirt plate is provided with a connecting hole.

[0010] Preferably, a T-shaped groove is provided on the surface of the central steel pipe, and the connecting pin is an L-shaped connecting pin. The L-shaped connecting pin of the buoyancy unit is inserted into the T-shaped groove of the central steel pipe to form a reliable connection with the central steel pipe.

[0011] Preferably, the interior of the central steel pipe is filled with concrete to improve the overall strength of the central steel pipe.

[0012] Preferably, the outer steel pipe is a hollow steel pipe, which is used to improve the bending rigidity of the steel pipe frame, and the internal space of the outer steel pipe is used for ballast and ventilation pipeline layout.

[0013] Preferably, structural adhesive is filled between the T-shaped groove and the connecting pin, and between the peripheral steel pipe and the through-hole of the buoyancy unit.

[0014] Preferably, the buoyancy units are connected together by bolts to form the buoyancy assembly.

[0015] Preferably, the end deck is a hollow watertight box structure made of steel, the end of the distributed steel pipe frame penetrates into the interior of the end deck and is welded to the load-bearing components, and the end deck is connected to the buoyancy block by bolts.

[0016] Preferably, the bolt and the nut matched with the bolt are both made of carbon fiber reinforced plastic.

[0017] Based on the same inventive concept, the present invention also provides a floating wind turbine foundation structure, which includes outer columns, lower connecting beams, lower diagonal braces, upper connecting beams and a central column. The central column is used to support the wind turbine and its tower. The outer columns are arranged around the central column. The central column and the outer columns are connected by upper connecting beams and lower connecting beams. The lower diagonal braces are arranged between adjacent outer columns. The outer columns and the lower connecting beams adopt the buoy structure.

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

[0019] 1. The buoy structure of the present invention fully utilizes the advantages of GFRP-steel composite materials and effectively reduces manufacturing costs. The use of lightweight and high-strength GFRP materials to make buoyancy blocks can significantly reduce the amount of steel used. Its seawater corrosion resistance also reduces the use of anti-corrosion coatings, greatly reducing manufacturing and maintenance costs; the embedded distributed steel pipe frame inside the buoyancy block makes up for the shortcomings of the insufficient toughness of the GFRP material and improves the bearing capacity of the buoy structure.

[0020] 2. The buoy structure of the present invention adopts an assembled design, which can realize modular construction and greatly shorten the construction period. The size specifications of the buoyancy unit are unified, and the distributed steel pipe frame structure is simple, which is conducive to standardized batch manufacturing in the factory. After being transported to the floating body construction site, it can be quickly assembled through L-shaped connecting pins, T-shaped grooves, and bolts, which significantly improves the construction and installation efficiency.

[0021] 3. The distributed steel tube frame, buoyancy module and end deck of the present invention form an efficient force-bearing system. The distributed steel tube frame provides bending and shear strength for the buoy structure; the buoyancy module provides necessary buoyancy for the buoy and provides strong lateral constraints on the steel tubes of the distributed steel tube frame to prevent buckling and failure of the steel tubes; the end deck strengthens the end constraints of the distributed steel tube frame and the buoyancy module, and also provides an interface for the connection of other components. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is an elevation view of the basic buoy structure of a floating wind turbine unit according to one embodiment of the present invention;

[0024] Figure 2 This is a combined structural diagram of a steel pipe frame and an end deck according to one embodiment of the present invention;

[0025] Figure 3 A schematic diagram of a steel pipe frame structure of one embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the end deck structure of one embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the structure of a buoyancy unit in one embodiment of the present invention;

[0028] Figure 6This is a schematic diagram of installing a buoyancy unit on a steel pipe frame according to one embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram of a five-column semi-submersible foundation of a floating wind turbine unit according to one embodiment of the present invention;

[0030] Figure 8 This is a schematic diagram of a four-column semi-submersible foundation of a floating wind turbine unit according to one embodiment of the present invention.

[0031] In the figure: buoyancy assembly 1; buoyancy unit 11; connecting pin 111; vertical skirt plate 112; transverse skirt plate 113; through hole 114; bolt hole 115; distributed steel pipe frame 2; central steel pipe 21; central steel pipe wall 211; T-shaped groove 212; concrete 213; outer steel pipe 22; end deck 3; end deck skirt plate 31; bolt hole 32; outer column 4; lower connecting beam 5; lower diagonal brace 6; upper connecting beam 7; middle column 8; wind turbine tower 9; wind turbine 10; mooring chain 11. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0033] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] See also Figure 1 and Figure 2 , Figure 1 This is the elevation view of the buoy structure suitable for the foundation of a floating wind turbine. Figure 2The figure is a combined structural diagram of a distributed steel tube frame and an end deck. The buoy structure includes a buoyancy block 1, a distributed steel tube frame 2 and an end deck 3. The buoyancy block 1 is composed of a plurality of buoyancy units 11 arranged in layers and connected to each other. The buoyancy block 1 is arranged between two end decks 3. The distributed steel tube frame 2 is composed of a central steel pipe 21 and a peripheral steel pipe 22, which is embedded in the buoyancy block 1. Its two ends penetrate into the end deck 3 respectively and are welded to the load-bearing components of the end deck 3.

[0036] Figure 3 The figure is a schematic diagram of a distributed steel tube frame structure. The central steel tube 21 and the peripheral steel tube 22 are arranged in parallel, wherein the central steel tube 21 is located in the center of the distributed steel tube frame, and a T-shaped groove 212 is provided on the surface of the steel tube for connection with the buoyancy unit 11; the interior of the central steel tube 21 is filled with concrete 213 to form a steel tube concrete structure to improve the bearing capacity of the steel tube frame; the peripheral steel tube 22 is arranged around the central steel tube 21 to improve the bending and torsional rigidity of the distributed steel tube frame, and its internal space can be used for the arrangement of ballast pipelines and ventilation pipelines.

[0037] Figure 4 The end deck 3 is a hollow watertight box structure made of steel, and a skirt plate 31 is arranged at the bottom thereof around the box. Bolt holes 32 are reserved on the skirt plate 31 for connecting with the buoyancy unit 11 of the buoyancy assembly 1 through bolts.

[0038] Figure 5It is a schematic diagram of the buoyancy unit structure. The buoyancy unit 11 is a hollow watertight box structure, and its outer shell is made of light-weight and high-strength glass fiber reinforced plastic (also known as fiberglass, the internationally recognized abbreviation symbol is GFRP or FRP). Two L-shaped connecting pins 111 are provided at the inner corners of the buoyancy unit 11, and their sizes match the T-shaped grooves 212 on the surface of the central steel pipe 21. The L-shaped connecting pins 111 are embedded in the T-shaped grooves 212 of the central steel pipe 21 to achieve a reliable connection with the distributed steel pipe frame 2. The box body is provided with a through hole 114 along the axial direction, and the diameter of the through hole is consistent with the diameter of the peripheral steel pipe 22, so that the peripheral steel pipe 22 can pass through the bottom of the buoyancy unit 11 and bear the force together with the buoyancy unit 11. Two vertical skirt plates 112 and two transverse skirt plates 113 are provided on the outer side of the buoyancy unit 11. The bolt holes reserved on the transverse skirt plates 113 are used to connect the upper and lower adjacent buoyancy units 11, and the bolt holes reserved on the vertical skirt plates 112 are used to connect the left and right adjacent buoyancy units 11. The interior of the buoyancy unit 11 can be used as a ballast tank, which is filled with a certain weight of seawater or fixed ballast to adjust the structural weight of the buoy, so as to achieve the purpose of adjusting the draft depth of the floating wind turbine foundation. The size specifications of each buoyancy unit 11 are unified, and multiple buoyancy units 11 are connected together by bolts to form a buoyancy assembly 1. The buoyancy unit 11 is an independent compartment in the buoy. When the buoy is partially damaged due to external impact loads, the multi-compartment design can effectively prevent the buoy from sinking due to the large amount of seawater pouring in.

[0039] Figure 6 The figure is a schematic diagram of the installation of the buoyancy unit on the distributed steel pipe frame. After the welding of the distributed steel pipe frame 2 and the lower deck 3 is completed, the buoyancy unit 11 is slid from the upper end of the steel pipe frame 2 to the bottom using the central steel pipe T-shaped groove 212 and the outer steel pipe 22 as the track. In order to reduce the friction between the components during the sliding process, lubricant is applied to the surface of the T-shaped groove 212 and the outer steel pipe 22. After sliding into place, the bolts on the skirt plates 112 and 113 of the buoyancy unit are installed to reliably connect the adjacent buoyancy units 11 and the lower deck 3. The bolts and nuts used for connection are made of corrosion-resistant carbon fiber reinforced plastic. Repeat the above installation steps until the assembly of multiple buoyancy units 11 is completed to form a buoyancy block 1. Due to manufacturing errors, there may be gaps between the T-shaped groove 212 and the L-shaped connecting pin 111, and the outer steel pipe 22 and the buoyancy unit opening 114. The gaps are filled with structural adhesive to prevent the buoyancy unit 11 from loosening. Finally, the other end of the steel pipe frame 2 is welded to the upper end deck 3, and connected to the buoyancy module 1 through bolts on the skirt plate 31. The surfaces of the distributed steel pipe frame 2 and the end deck 3 are coated with protective paint, and sacrificial anodes are used to prevent seawater corrosion of metal components.

[0040] Preferably, for a buoy with a smaller cross-sectional size, the buoyancy assembly 1 of a certain layer may be composed of a single buoyancy unit 11, in which case the vertical skirt plate 112 of the buoyancy unit 11 is removed, and only the transverse skirt plate 113 is retained for connection with the buoyancy units 1 of the upper and lower layers.

[0041] Figure 7 The schematic diagram of the five-column semi-submersible foundation of a floating wind turbine using the above-mentioned buoy structure is shown. The foundation is a semi-submersible floating structure, which is connected by an outer column 4, a lower connecting beam 5, a lower diagonal brace 6, an upper connecting beam 7 and a middle column 8. The semi-submersible foundation is anchored to the seabed by a catenary mooring chain 11. Four outer columns 4 are arranged around the middle column 8, and the buoy structure provided by the present invention is adopted. Six layers of buoyancy blocks 1 are arranged between the two steel end decks 3, and each layer of buoyancy blocks 1 is composed of four buoyancy units 11. The outer columns 4 are connected to the middle column 8 through the lower connecting beam 5 and the upper connecting beam 7. The lower connecting beam 5 also adopts the buoy structure provided by the present invention, and five layers of buoyancy blocks are arranged between the two steel end decks 3. Since the cross-sectional size of the lower connecting beam 5 in this example is small, each layer of buoyancy blocks is composed of a single buoyancy unit. The two steel end decks are welded to the side of the lower end deck of the outer column 4 and the lower side of the middle column 8, respectively. The middle column 8 is a steel hollow watertight structure, and its top supports the wind turbine 10 and its tower 9. The two ends of the upper connecting beam 7 are welded to the side of the upper deck of the outer column 4 and the upper side of the middle column 8. Four lower diagonal braces 8 are also used to connect the four outer columns 4 to increase the overall strength of the structure. Applying the buoy structure provided by the present invention to the outer columns 4 and the lower connecting beam 5 of the foundation of the floating wind turbine can significantly reduce the weight of the floating body and reduce the amount of steel used. At the same time, the convenient installation of the buoy structure can effectively reduce the construction period of the foundation, thereby reducing the construction cost.

[0042] Preferably, the buoy structure provided by the present invention can also be applied to a four-column semi-submersible foundation of a floating wind turbine, such as Figure 8 As shown. Similar to the four-column semi-submersible foundation, the floating structure consists of outer columns 4, lower connecting beams 5, lower diagonal braces 6, upper connecting beams 7 and middle columns 8. The semi-submersible foundation is anchored to the seabed by a catenary mooring chain 11. The buoy structure of the present invention is applied to three outer columns 4 and three lower connecting beams 5. The middle column 8 is a hexagonal prism design, which is used to support the wind turbine 10 and its tower 9.

[0043] The above is only a specific implementation scheme of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the art can make many possible changes and modifications to the technical scheme of the present invention by using the technical content disclosed above without departing from the scope of the technical scheme of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical scheme of the present invention should fall within the protection scope of the technical scheme of the present invention.

Claims

1. A buoy structure suitable for the foundation of a floating wind turbine, characterized in that include: The distributed steel pipe frame is the main load-bearing component of the buoy, including a central steel pipe located in the center and peripheral steel pipes arranged around the central steel pipe. The central steel pipe and the peripheral steel pipe are arranged in parallel; The end deck is a force transmission member at the end of the buoy, including an upper end deck and a lower end deck respectively connected to the two ends of the distributed steel pipe frame; The buoyancy assembly is made of glass fiber reinforced plastic and is composed of a plurality of buoyancy units connected in layers to the central steel pipe and the peripheral steel pipes of the distributed steel pipe frame. Each buoyancy unit is a hollow watertight box structure filled with water ballast or solid ballast, and each buoyancy unit includes a connecting pin connected to the central steel pipe, a through hole for the peripheral steel pipe to pass through, and a skirt plate for connecting to an adjacent buoyancy unit or an end deck, wherein the connecting pin is arranged on the inner side of the buoyancy unit, the skirt plate is arranged on the outer side of the buoyancy unit, and the skirt plate is provided with a connecting hole.

2. The buoy structure suitable for the foundation of a floating wind turbine according to claim 1, characterized in that: The surface of the central steel pipe is provided with a T-shaped groove, and the connecting pin is an L-shaped connecting pin. The L-shaped connecting pin of the buoyancy unit is inserted into the T-shaped groove of the central steel pipe to form a connection with the central steel pipe.

3. The buoy structure suitable for the foundation of a floating wind turbine according to claim 2, characterized in that: The interior of the central steel pipe is filled with concrete.

4. The buoy structure suitable for the foundation of a floating wind turbine according to claim 1, characterized in that: The outer steel pipe is a hollow steel pipe, and the inner space of the outer steel pipe is used for ballast and ventilation pipeline arrangement.

5. The buoy structure suitable for the foundation of a floating wind turbine according to claim 2, characterized in that: Structural adhesive is filled between the T-shaped groove and the connecting pin, and between the peripheral steel pipe and the through hole of the buoyancy unit.

6. The buoy structure suitable for the foundation of a floating wind turbine according to claim 1, characterized in that: The buoyancy units are connected into one body by bolts to form the buoyancy assembly block.

7. The buoy structure suitable for the foundation of a floating wind turbine according to claim 1, characterized in that: The end deck is a hollow watertight box structure made of steel. The end of the distributed steel pipe frame penetrates into the end deck and is welded to the load-bearing components. The end deck is connected to the buoyancy block by bolts.

8. The buoy structure suitable for the foundation of a floating wind turbine according to claim 7, characterized in that: The bolt and the nut matched with the bolt are both made of carbon fiber reinforced plastic.

9. A floating wind turbine foundation structure, comprising outer columns, lower connecting beams, lower diagonal braces, upper connecting beams and a middle column, wherein the middle column is used to support the wind turbine and its tower, the outer columns are arranged around the middle column, the middle column and the outer columns are connected by upper connecting beams and lower connecting beams, and the lower diagonal braces are arranged between adjacent outer columns, characterized in that: The outer column and the lower connecting beam adopt the pontoon structure described in any one of claims 1 to 8.

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