A pontoon structure and foundation structure suitable for a floating wind turbine foundation

Abstract

The application discloses a kind of floating wind turbine foundation suitable for pontoon structure and foundation structure, it includes: distributed steel pipe frame, including center steel pipe and the peripheral steel pipe being arranged around center steel pipe;End deck, including the upper end deck and lower end deck being connected with the both ends of distributed steel pipe frame respectively;Buoyancy block, made of glass fiber reinforced plastic, is connected with center steel pipe and peripheral steel pipe by multiple buoyancy units layering, each buoyancy unit is hollow watertight box structure, internal filling water ballast or solid ballast, and each buoyancy unit includes connecting pin connected with center steel pipe, perforation for peripheral steel pipe to pass through, skirt plate for being connected with adjacent buoyancy unit or end deck, connecting pin is arranged inside buoyancy unit, skirt plate is arranged outside buoyancy unit, and connecting hole is provided on skirt plate.The application effectively reduces manufacturing and maintenance cost, while modular construction can be realized, greatly shorten construction period.

Description

Technical Field

[0001] This invention relates to offshore wind power generation technology, specifically to a floating structure and foundation structure suitable for floating wind turbine foundations. Background Technology

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

[0003] Floating wind turbine foundations typically consist of multiple vertical or horizontal pontoons. As key components of floating foundations, pontoons significantly impact the foundation's economy, safety, and reliability. Traditionally, pontoons are constructed using pure steel, concrete, or a steel-concrete composite material. Due to the high density of steel and concrete, the volume of the pontoons needs to be increased to provide sufficient buoyancy, leading to increased material usage and construction costs. Furthermore, constructing pure steel pontoon structures involves extensive welding, while concrete pontoon structures require formwork, rebar tying, pouring, and curing, resulting in lengthy construction cycles and hindering large-scale construction. Summary of the Invention

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

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A floating structure suitable for floating wind turbine foundations, comprising:

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

[0008] End decks are the force-transmitting components at the ends of the pontoons, including upper and lower end decks that are respectively connected to both ends of the distributed steel tube frame;

[0009] The buoyancy block is made of glass fiber reinforced plastic, and is composed of a plurality of buoyancy units layered and connected with a center steel pipe and a peripheral steel pipe 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 comprises a connecting pin connected with the center steel pipe, a perforation for the peripheral steel pipe to pass through, and a skirt plate for connecting with an adjacent buoyancy unit or an end deck, the connecting pin is arranged inside the buoyancy unit, the skirt plate is arranged outside the buoyancy unit, and the skirt plate is provided with a connecting hole.

[0010] Preferably, the center 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 center steel pipe to form a reliable connection with the center steel pipe.

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

[0012] Preferably, the peripheral steel pipe is a hollow steel pipe for improving the bending stiffness of the steel pipe frame, and the internal space of the peripheral steel pipe is used for ballast and ventilation pipeline arrangement.

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

[0014] Preferably, the buoyancy units are integrally connected by bolts to form the buoyancy block.

[0015] Preferably, the end deck is a steel hollow watertight box structure, the end of the distributed steel pipe frame penetrates into the inside of the end deck and is welded to a force member, and the end deck is connected to the buoyancy block by bolts.

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

[0017] Based on the same inventive concept, the application also provides a floating wind turbine generator foundation structure, which comprises outer columns, lower connecting beams, lower diagonal braces, upper connecting beams and middle columns, the middle columns are used for supporting a wind turbine generator and a tower thereof, the outer columns are arranged around the middle columns, the middle columns and the outer columns are connected through the upper connecting beams and the lower connecting beams, the lower diagonal braces are arranged between adjacent outer columns, and the outer columns and the lower connecting beams adopt the floating cylinder structure.

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

[0019] 1. The buoy structure of the present application fully utilizes the advantages of GFRP-steel composite material, effectively reducing the manufacturing cost. The buoyancy block is made of lightweight and high-strength GFRP material, which can significantly reduce the amount of steel used, and its resistance to seawater corrosion reduces the use of corrosion-resistant coating, greatly reducing the manufacturing and maintenance cost; the distributed steel pipe frame is embedded in the buoyancy block to compensate for the lack of toughness of GFRP material and improve the carrying capacity of the buoy structure.

[0020] 2. The buoy structure of the present application adopts assembly type design, which can realize modular construction and greatly shorten the construction period. The size of the buoyancy unit is uniform, and the distributed steel pipe frame structure is simple, which is beneficial to standardized and batch manufacturing in the factory. After transportation 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 pipe frame, buoyancy block and end deck of the present application form an efficient stress system. The distributed steel pipe frame provides bending and shear strength for the buoy structure; the buoyancy block provides the necessary buoyancy for the buoy while providing strong lateral restraint for the steel pipes of the distributed steel pipe frame to prevent buckling failure of the steel pipes; the end deck enhances the end restraint of the distributed steel pipe frame and the buoyancy block, and also provides an interface for the connection of other components. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0023] Figure 1 It is a front view of the floating wind turbine foundation buoy structure of one of the embodiments of the present application;

[0024] Figure 2 It is a combined structure diagram of the steel pipe frame and the end deck of one of the embodiments of the present application;

[0025] Figure 3 It is a schematic diagram of the steel pipe frame structure of one of the embodiments of the present application;

[0026] Figure 4 It is a schematic diagram of the end deck structure of one of the embodiments of the present application;

[0027] Figure 5 It is a schematic diagram of the buoyancy unit structure of one of the embodiments of the present application;

[0028] Figure 6The installation schematic diagram of the buoyancy unit of one of the embodiments of the present application in the steel pipe frame;

[0029] Figure 7 The schematic diagram of the five-column semi-submersible foundation of the floating wind turbine unit of one of the embodiments of the present application;

[0030] Figure 8 The schematic diagram of the four-column semi-submersible foundation of the floating wind turbine unit of one of the embodiments of the present application.

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

[0032] The present application will be further described below in connection with specific preferred embodiments, but the scope of protection of the present application is not limited by the same.

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

[0034] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] Reference Figure 1 and Figure 2 , Figure 1 is a front view of the pontoon structure suitable for the foundation of the floating wind turbine unit, Figure 2The figure is a combination structure of distributed steel pipe frame and end deck. The pontoon structure includes a buoyancy module 1, a distributed steel pipe frame 2 and an end deck 3. The buoyancy module 1 is composed of a plurality of buoyancy units 11 arranged in layers and connected with each other, and is arranged between two end decks 3. The distributed steel pipe frame 2 is composed of a central steel pipe 21 and a peripheral steel pipe 22, is embedded in the buoyancy module 1, and penetrates into the interior of the end deck 3 at both ends and is welded to the load-bearing member of the end deck 3.

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

[0037] Figure 4 The figure is a schematic diagram of the end deck structure. The end deck 3 is a steel hollow water-tight box structure, the bottom end of which is provided with a skirt plate 31 around the box, and the skirt plate 31 is provided with bolt holes 32 for connection with the buoyancy unit 11 of the buoyancy module 1 through bolts.

[0038] Figure 5Figure 1 is a schematic diagram of a buoyancy unit structure. The buoyancy unit 11 is a hollow watertight box structure, the outer shell of which is made of glass fiber reinforced plastic (also known as glass steel, internationally recognized abbreviation GFRP or FRP) which is light in weight and strong in strength. Two L-shaped connecting pins 111 are arranged at the corners inside the buoyancy unit 11, the size of which matches the T-shaped groove 212 on the surface of the center steel pipe 21. By embedding the L-shaped connecting pins 111 into the T-shaped groove 212 of the center steel pipe 21, reliable connection with the distributed steel pipe frame 2 can be achieved. The box is provided with a through hole 114 along the axial direction, the hole diameter of which is consistent with the pipe 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 force together with the buoyancy unit 11. Two vertical skirt plates 112 and two horizontal skirt plates 113 are arranged on the outer side of the buoyancy unit 11, and bolt holes are reserved on the horizontal skirt plates 113 for the connection of adjacent buoyancy units 11 above and below, and bolt holes are reserved on the vertical skirt plates 112 for the connection of adjacent buoyancy units 11 left and right. The inside of the buoyancy unit 11 can be used as a ballast tank, which is filled with a certain weight of seawater or fixed ballast, used to adjust the structural weight of the buoyancy, to achieve the purpose of adjusting the draft depth of the floating wind turbine foundation. The size specifications of each buoyancy unit 11 are uniform, and multiple buoyancy units 11 are connected by bolts to form a buoyancy block 1. The buoyancy unit 11 serves as an independent cabin in the buoyancy, and when the local damage of the buoyancy caused by external impact load occurs, the design of multiple cabins can effectively prevent the buoyancy from sinking due to the large amount of seawater pouring in.

[0039] Figure 6 Figure 2 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 center steel pipe T-shaped groove 212 and the peripheral steel pipe 22 are used as tracks, and the buoyancy unit 11 is slid from the upper end to the bottom of the steel pipe frame 2. In order to reduce the friction between the components during sliding, lubricant is applied to the surface of the T-shaped groove 212 and the peripheral steel pipe 22. After sliding in place, the bolts on the skirt plates 112, 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 between the peripheral steel pipe 22 and the buoyancy unit opening 114. Structure glue is used to fill the gaps to prevent the buoyancy unit 11 from loosening. Finally, the other end of the steel pipe frame 2 is welded with the upper deck 3, and connected with the buoyancy block 1 through the bolts on the skirt plate 31. The distributed steel pipe frame 2 and the deck 3 are coated with protective paint, and the sacrificial anode method is used to prevent seawater corrosion of the metal components.

[0040] For the floating buoy structure with smaller cross-sectional size, the buoyancy block 1 of a certain layer can be composed of a single buoyancy unit 11, in which case the vertical skirt plate 112 of the buoyancy unit 11 is cancelled, and only the horizontal skirt plate 113 is reserved for connection with the buoyancy units 1 of the upper and lower layers.

[0041] Figure 7 A five-column semi-submersible foundation of a floating wind turbine using the floating buoy structure is shown in the figure. The foundation is a semi-submersible floating structure, which is composed of outer columns 4, lower connecting beams 5, lower braces 6, upper connecting beams 7 and a middle column 8, and is anchored to the seabed by catenary mooring chains 11. Four outer columns 4 are arranged around the middle column 8, and the floating buoy structure provided by the present application is used. 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 beams 5 and the upper connecting beams 7. The lower connecting beams 5 also use the floating buoy structure provided by the present application, and five layers of buoyancy blocks are arranged between the two steel end decks 3. Since the cross-sectional size of the lower connecting beams 5 in this example is small, each layer of buoyancy blocks is composed of a single buoyancy unit. The two steel end decks are respectively welded to the side of the lower end deck of the outer column 4 and the lower side of the middle column 8. The middle column 8 is a steel hollow water-tight structure, and its top supports the wind turbine 10 and its tower 9. The two ends of the upper connecting beams 7 are respectively welded to the side of the upper end deck of the outer column 4 and the upper side of the middle column 8. Four lower braces 6 are also used to connect the four outer columns 4 to increase the overall strength of the structure. The application of the floating buoy structure provided by the present application to the outer columns 4 and the lower connecting beams 5 of the floating wind turbine foundation can significantly reduce the weight of the floating body and the amount of steel used, and at the same time, taking advantage of the convenient installation characteristics of the floating buoy structure, the construction period of the foundation can be effectively reduced, thereby reducing the construction cost.

[0042] Preferably, the floating buoy structure provided by the present application can also be applied to a four-column semi-submersible foundation of a floating wind turbine, as shown in the figure. Figure 8 Similar to the four-column semi-submersible foundation, the floating body structure is composed of outer columns 4, lower connecting beams 5, lower braces 6, upper connecting beams 7 and a middle column 8. The semi-submersible foundation is anchored to the seabed by catenary mooring chains 11. The floating buoy structure of the present application is applied to three outer columns 4 and three lower connecting beams 5. The middle column 8 is designed as a hexagonal column to support the wind turbine 10 and its tower 9.

[0043] The above merely describes specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can make many possible changes and modifications to the technical solutions of the present application, or modify equivalent embodiments with equivalent changes, without departing from the scope of the technical solutions of the present application, by using the technical contents disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the content of the technical solutions of the present application, shall fall within the protection scope of the technical solutions of the present application.

Claims

1. A buoyant structure suitable for use in a floating wind turbine foundation, the structure comprising include: The distributed steel pipe frame is the main load-bearing component of the pontoon, including a central steel pipe located at the center and peripheral steel pipes arranged around the central steel pipe, with the central steel pipe and peripheral steel pipes arranged in parallel. End decks are the force-transmitting components at the ends of the pontoons, including upper and lower end decks that are respectively connected to both ends of the distributed steel tube frame; The buoyancy module, made of glass fiber reinforced plastic, is composed of multiple buoyancy units connected in layers to the central and outer steel pipes of the distributed steel pipe frame. Each buoyancy unit is a hollow watertight box structure, which is filled with water ballast or solid ballast. Each buoyancy unit includes a connecting pin connected to the central steel pipe, a perforation for the outer steel pipe to pass through, and a skirt plate for connecting to adjacent buoyancy units or end decks. The connecting pin is arranged inside the buoyancy unit, and the skirt plate is arranged outside the buoyancy unit, and the skirt plate is provided with connecting holes. 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. The end deck is a hollow, watertight steel box structure. The end of the distributed steel pipe frame penetrates into the interior of the end deck and is welded to the load-bearing components. The end deck is also connected to the buoyancy block by bolts.

2. A buoy structure suitable for use in a floating wind turbine generator foundation according to claim 1, wherein, The central steel pipe is filled with concrete.

3. The buoy structure suitable for use in a floating wind turbine generator foundation according to claim 1, wherein, The outer steel pipe is a hollow steel pipe, and the internal space of the outer steel pipe is used for ballast and ventilation pipeline layout.

4. The buoy structure suitable for use in a floating wind turbine generator foundation according to claim 1, wherein, Structural adhesive is used to fill the gap between the T-shaped groove and the connecting pin, and between the outer steel pipe and the buoyancy unit.

5. The buoy structure suitable for use in a floating wind turbine generator foundation according to claim 1, wherein, The buoyancy units are connected together by bolts to form the buoyancy block.

6. The buoy structure suitable for use in a floating wind turbine foundation according to claim 1, wherein, Both the bolt and the nut that matches the bolt are made of carbon fiber reinforced plastic.

7. A floating wind turbine foundation structure comprising outer columns, lower tie beams, lower braces, upper tie beams and a central column for supporting a wind turbine and its tower, the outer columns being arranged around the central column, the central column being connected to the outer columns by upper and lower tie beams, the lower braces being provided between adjacent outer columns, characterised in that, The outer column and the lower connecting beam adopt the float structure as described in any one of claims 1-6.

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