An offshore wind turbine foundation, towing and installation method

Abstract

The present invention discloses an offshore wind turbine foundation, towing and installation method. The sliding base and fixed base of the hollow structure in the foundation can jointly provide buoyancy. The upper and lower bases can be superimposed to provide sufficient buoyancy and stability to enable the overall structure including the wind turbine foundation, tower and wind turbine to float on the sea surface. The overall structure has self-floating stability, does not require any special marine transportation equipment, and can be transported at sea only by towing by tugboat, which reduces the cost of offshore towing wind turbine foundations, greatly improves the flexibility of marine transportation, and is conducive to improving marine transportation efficiency; in this way, the foundation can be prefabricated and installed on land together with the upper tower and wind turbine; during installation, the annular tube skirt slides down to the seabed surface, and the suction penetration process can accurately adjust the overall verticality of the foundation to meet the overall requirements of the installation. The entire installation process only requires a pump skid system and an auxiliary ship, without any large-scale professional construction ships such as floating cranes, and no seabed pretreatment is required, which saves installation costs and improves installation efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine foundation transportation, and in particular to an offshore wind turbine foundation, towing and installation method. Background Art

[0002] The wind turbine foundation forms mainly used in the offshore wind power projects under construction are: jacket foundation and single pile foundation. The single pile foundation is suitable for areas with a water depth of 20~30m, while the jacket foundation is suitable for areas with a water depth of 20~50m.

[0003] The offshore wind turbine foundation is very heavy, so it is very difficult to transport and install it at sea. At present, the wind turbine foundation is divided into several sections, each section is towed to the offshore platform by a tugboat, and then assembled on the offshore platform before on-site construction and installation. The existing towing and installation methods have the following problems, mainly reflected in: 1. Because the wind turbine foundation is very large in size and weight, a large tugboat is required for towing, and a heavy floating crane is required to assist in installation, which has high construction costs. 2. There are many offshore installation construction procedures. For wind power construction sites in tropical or subtropical areas, the sea conditions are harsh, and the effective construction window period is small and discontinuous, which increases the cost of offshore construction operations. 3. For offshore areas with deep water and harsh sea conditions, the construction cost of offshore wind turbine installation operations is high, and due to the deep water depth, there are currently fewer ships and machines that can be used.

[0004] Therefore, how to improve the flexibility of barrel foundation marine transportation and improve transportation efficiency is the goal that technicians in this field always pursue. Summary of the invention

[0005] The purpose of the present invention is to achieve high efficiency and low cost in transportation and installation of offshore wind turbine foundations.

[0006] The present invention provides an offshore wind turbine foundation, comprising a central column, a fixed base and a sliding base; the fixed base is fixed to the root section of the central column, an annular tube skirt is fixed to the lower surface of the fixed base, the annular tube skirt surrounds a cavity with an opening facing downward, and the interior of the cavity is divided by a partition to form a plurality of compartments;

[0007] Both the fixed base and the sliding base are hollow concrete structures, and the hollow inner cavity of the fixed base and the hollow inner cavity of the sliding base are formed with a plurality of independent compartments;

[0008] A through hole is provided in the middle of the sliding base, and the sliding base is located above the fixed base, the central column passes through and is located inside the through hole, and the sliding base can move axially relative to the central column;

[0009] It also includes an adjustment device. During floating transportation, the hollow inner cavities of the sliding base and the fixed base are partially hollowed out to provide buoyancy; the adjustment device is used to adjust the amount of medium inside each compartment to keep the overall center of gravity of the offshore wind turbine foundation stable during floating transportation;

[0010] It also includes fillers, which are placed in each compartment of the sliding base during fixed installation, so that the sliding base can slide axially to the installation position at the root of the central column and provide downward pressure on the annular tube skirt.

[0011] When the offshore wind turbine foundation is in a towing state, the sliding base and the fixed base of the hollow structure jointly provide buoyancy, and the superposition of the upper and lower bases can provide sufficient buoyancy to make the entire structure (including the wind turbine foundation, tower and wind turbine unit) float on the sea surface. The whole structure has self-floating stability and does not require any special marine transportation equipment. It can be transported at sea only by towing by tugboat, which reduces the cost of offshore towing wind turbine foundations, greatly improves the flexibility of marine transportation, and is conducive to improving marine transportation efficiency. In this way, the foundation can be prefabricated and installed on land together with the upper tower and wind turbine unit; and the amount of medium inside each compartment of the sliding base and the fixed base can be adjusted by the adjustment device, so that the overall center of gravity of the offshore wind turbine foundation can be kept stable during floating transportation.

[0012] When the offshore wind turbine foundation is towed to the offshore installation location, concrete or fluid is first filled into the fixed base, so that the fixed base and the annular skirt drive the central column to move downward until the annular skirt is inserted into the seabed mud surface. During this process, the sliding base always floats on the sea surface under the action of its own buoyancy, which can maintain the stability of the central column. Without the assistance of a large floating crane, the annular skirt and the fixed base can be stably inserted into the seabed surface, and the suction pump skid system and the bottom suction cylinder structure are used for suction penetration to carry out foundation installation. The suction penetration process can accurately adjust the overall verticality of the foundation to meet the overall requirements of the installation. The entire installation process only requires a pump skid system and an auxiliary ship, without any large professional construction ships such as floating cranes, and as there is no need for seabed pretreatment, it saves installation costs, improves installation efficiency, and further reduces the cost of offshore wind turbine foundation installation. Finally, the sliding base filled with fillers sinks to the top of the fixed base, which can further enhance the bearing capacity and anti-overturning ability of the foundation.

[0013] Optionally, each of the compartments has an opening, and the regulating device includes a ballast system and a valve installed at each opening, wherein the valve controls the opening to be opened or closed, and the valve opens or closes the opening according to a signal from the ballast system to pump in or out the medium of the corresponding compartment.

[0014] Optionally, the arrangement of the internal compartments of the fixed base and the sliding base corresponds to the compartment arrangement positions of the annular tube skirt.

[0015] Optionally, the cavity of the annular skirt is provided with an annular partition coaxial with the annular partition, and a central compartment is formed inside the annular partition. It also includes a plurality of radial partitions, each of which is arranged between the annular partition and the inner wall of the annular skirt and is evenly distributed along the circumferential direction to divide the annular skirt and the annular partition into a plurality of peripheral compartments.

[0016] Optionally, each compartment inside the annular skirt is provided with a control port for connecting to an external suction pump. Under normal circumstances, the control port is in a closed state. During installation, the suction pump is used to realize negative pressure installation of each compartment and control the pressure difference between each compartment to realize the overall horizontal adjustment of the offshore wind turbine foundation.

[0017] Optionally, the filler is concrete or seawater; when the offshore wind turbine foundation is installed, each compartment of the sliding base is filled with the filler so that the sliding base slides downward along the central column and is supported on the fixed base.

[0018] Optionally, when in the installation state, each compartment of the fixed base is also filled with concrete.

[0019] Optionally, the sliding base, the fixed base and the annular skirt are all reinforced concrete bodies.

[0020] Optionally, one of the central column and the sliding base is provided with a groove, and the other is provided with a sliding block that slides in cooperation with the groove, and the groove is arranged along the axial direction; the number of the groove is at least one.

[0021] In addition, the present invention also provides a method for towing and installing an offshore wind turbine foundation as described in any one of the above items, comprising the following contents:

[0022] Pre-assemble the tower, wind turbine and offshore wind turbine foundation to form an integrated structure and place it in the sea;

[0023] During the towing process, the amount of medium inside each compartment of the sliding base and the fixed base is adjusted to keep the overall center of gravity of the offshore wind turbine foundation stable during floating transportation;

[0024] After being towed to the installation location, the fixed base is filled with fluid medium or concrete. Under the action of deadweight, the fixed base and the annular skirt drive the central column to sink to the mud surface on the seabed. The annular skirt and the mud surface form a sealed environment. The seawater in the annular skirt is pumped out through the suction pump skid system. The annular skirt penetrates into the soil under the action of negative pressure until the top of the annular skirt is completely in contact with the mud surface, thereby achieving a stable combination of the foundation and the seabed.

[0025] The method of the present invention is implemented on the basis of the above-mentioned offshore wind turbine foundation, so the method also has the above-mentioned technical effects of the offshore wind turbine foundation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of an offshore wind turbine foundation in an installation state in one embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structural state of an offshore wind turbine foundation after it is completely installed and fixed in one embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the internal structure of the annular tube skirt in one embodiment of the present invention;

[0029] Figure 4 A schematic diagram of a towing and installation method of an integral structure including an offshore wind turbine foundation in one embodiment of the present invention.

[0030] in, Figures 1 to 4 middle:

[0031] 10-central column; 20-sliding base; 30-fixed base; 40-annular tube skirt; 41-annular partition; 42-radial partition; 40a-central compartment; 40b-peripheral compartment; 50-fan. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0033] Please refer to Figures 1 to 4 , Figure 1 It is a structural schematic diagram of an offshore wind turbine foundation in an installation state in one embodiment of the present invention; Figure 2 This is a schematic diagram of the structural state of an offshore wind turbine foundation after it is completely installed and fixed in one embodiment of the present invention; Figure 3 This is a schematic diagram of the internal structure of the annular tube skirt in one embodiment of the present invention; Figure 4 FIG. 1 is a schematic diagram of a method for towing and installing an overall structure including an offshore wind turbine foundation in an embodiment of the present invention, wherein Figure 4S1, S2 and S3 in the figure respectively represent the towing state, one of the states of the installation and fixing process, and the installation and fixing end state.

[0034] The present invention provides an offshore wind turbine foundation, which includes a central column 10, a fixed base 30 and a sliding base 20; the fixed base 30 and the sliding base 20 are both hollow concrete structures. That is, the fixed base 30 and the sliding base 20 have a hollow inner cavity inside, which can be ballast water discharged during marine transportation to provide a certain buoyancy.

[0035] Specifically, the hollow inner cavity of the fixed base 30 and the hollow inner cavity of the sliding base 20 are both formed with a plurality of independent chambers. The offshore wind turbine foundation also includes an adjustment device capable of adjusting the medium inside the chamber so that the overall center of the offshore wind turbine foundation is stable during floating transportation.

[0036] The top of the central column 10 is used to install the wind turbine 50, that is, the top of the central column 10 is usually provided with an installation platform for installing components such as the equipment cabin and the wind turbine 50. The root section of the central column 10 is fixed with a fixed base 30. It should be noted that this article takes the offshore wind turbine foundation in a fixed state as a reference, and the end of the central column 10 close to the seabed installation platform is defined as the root, and the end where the wind turbine is installed is the top.

[0037] The offshore wind turbine foundation of the present invention also includes fillers. When fixedly installed, the fillers are placed in each compartment of the sliding base 20 so that the sliding base 20 slides axially to the installation position at the root of the central column 10 and provides downward pressure on the annular skirt 40. The filler can be a fluid medium or concrete and any low-cost material that acts as a weight. The fluid medium can be seawater. Similarly, the interior of the fixed base 30 can also be filled with concrete or a fluid medium to drive the fixed base to move downward and can play a role in reinforcing the stability of the structure.

[0038] A through hole is provided in the middle of the sliding base 20 in the present invention, and the central column 10 passes through and is located inside the through hole. The sliding base 20 is located above the fixed base 30, and the sliding base 20 can move axially relative to the central column 10; that is, the sliding base 20 can slide up and down along the central column 10.

[0039] Based on the above structure, the present invention also provides a method for towing and installing an offshore wind turbine foundation, comprising:

[0040] The tower, wind turbine 50 and offshore wind turbine foundation are pre-assembled to form an integral structure and placed in the sea; see Figure 4 The state shown in S1;

[0041] During the towing process, the amount of medium inside each compartment of the sliding base 20 and the fixed base 30 is adjusted to keep the overall center of gravity of the offshore wind turbine foundation stable during floating transportation; specifically, when the offshore wind turbine foundation is in a towing state, the hollow fixed base 30 and the sliding base 20 jointly provide a predetermined buoyancy, and the superposition of the upper and lower bases can provide sufficient buoyancy to make the entire structure (including the wind turbine foundation, tower and wind turbine unit) float on the sea surface, and the whole has self-floating stability, without any special marine transportation equipment, and can be transported at sea only by towing by tugboat, thereby reducing the cost of offshore towing wind turbine foundations, greatly improving the flexibility of marine transportation, and being conducive to improving marine transportation efficiency; in this way, the foundation can be prefabricated and installed on land together with the upper tower and wind turbine unit; and the amount of medium inside each compartment of the sliding base 20 and the fixed base 30 is adjusted by the adjustment device, so that the overall center of gravity of the offshore wind turbine foundation can be kept stable during floating transportation.

[0042] After being transported to the installation location, the installation process is as follows:

[0043] Because the lower surface of the fixed base 30 is fixed with an annular skirt 40, the annular skirt 40 encloses a cavity with the opening facing downward, and the interior of the cavity is divided by partitions to form multiple compartments; during installation, the fixed base 30 is first filled with a fluid medium or concrete, and under the action of deadweight, the fixed base 30 and the annular skirt 40 drive the central column 10 to sink to the mud surface of the seabed, and the annular skirt 40 and the mud surface form a sealed environment. The seawater in the annular skirt 40 is pumped out through the suction pump skid system, and the annular skirt 40 penetrates into the soil under the action of negative pressure until the top of the annular skirt 40 is completely in contact with the mud surface, thereby realizing a stable combination of the foundation and the seabed. Please refer to Figure 4 The state shown in S2;

[0044] In the second step, the sliding base 20 is filled with fillers and slides down to the top of the fixed base 30 under the action of its own weight to achieve the effect of pressing the foundation to improve the bearing capacity and anti-overturning ability of the foundation. Figure 4 The state shown in S3.

[0045] During the installation of the offshore wind turbine foundation, since the sliding base 20 is still mostly on the sea surface, the sliding base 20 can maintain the stability of the central column, so that the annular skirt 40 and the fixed base 30 can be stably inserted into the seabed without the assistance of a large floating crane. The suction penetration process can accurately adjust the overall verticality of the foundation to meet the overall requirements of the installation. The entire installation process only requires a pump skid system and an auxiliary ship, without any large professional construction ships such as floating cranes, and as there is no need for seabed pretreatment, it saves installation costs, improves installation efficiency, and further reduces the cost of offshore wind turbine foundation installation.

[0046] The specific shapes of the sliding base 20 and the fixed base 30 can be set as needed. The outer walls of the two bases can be corrosion-resistant to increase their service life. This article provides a specific implementation method in which the sliding base 20, the fixed base 30 and the annular skirt 40 are all concrete steel structure bodies. Of course, the materials of the three can also be other materials. This article does not limit the specific shapes and materials.

[0047] In addition, the size of the hollow inner cavity of the sliding base 20 is determined according to the buoyancy required to be provided. Not disclosing the size of the inner cavity herein does not hinder the understanding and implementation of the technical solution of this invention by those skilled in the art.

[0048] Of course, in order to achieve the filling of the medium inside the fixed base 30 and the sliding base 20, both must be provided with openings that can be opened and closed. In this specific embodiment, in the above embodiments, each of the cabins has an opening, and the regulating device includes a ballast system and a valve installed at each opening, and the valve controls the opening or closing of the opening. The valve opens or closes the opening according to the ballast system signal to pump in or out the medium of the corresponding cabin.

[0049] The ballast system is not introduced in detail in this article, and reference may be made to the prior art.

[0050] As described above, the inner cavities of the sliding base 20 and the fixed base 30 are divided into a plurality of independent chambers, which makes it convenient to adjust the fluid medium inside the corresponding chambers according to the actual conditions of transportation and installation to achieve stable transportation.

[0051] Furthermore, the arrangement of the internal compartments of the fixed base 30 and the sliding base 20 corresponds to the compartment arrangement position of the annular skirt 40. That is, the compartments of the fixed base 30, the sliding base 20 and the annular skirt 40 are of the same size, shape and position. This facilitates the installation and adjustment of the fan foundation.

[0052] In a specific embodiment, the cavity of the annular skirt 40 is provided with an annular baffle 41 coaxial therewith, and a central compartment 40a is formed inside the annular baffle 41, and the cavity of the annular skirt 40 also includes a plurality of radial baffles 42, each radial baffle 42 is arranged between the annular baffle 41 and the inner wall of the annular skirt 40 and is evenly distributed along the circumferential direction, so as to divide the annular skirt 40 and the annular baffle 41 into a plurality of peripheral compartments 40b. Each peripheral compartment 40b is of the same size, and the figure shows a specific embodiment of dividing and forming six peripheral compartments 40b. Of course, the number of compartments is not limited to that described herein, and those skilled in the art can reasonably set it according to the actual wind turbine foundation.

[0053] The structure of the central compartment 40a and the plurality of peripheral compartments 40b further facilitates the adjustment of the levelness when installing the wind turbine foundation.

[0054] Furthermore, each compartment is provided with a control port for connecting to an external suction pump. Under normal circumstances, the control port is in a closed state. During installation, negative pressure installation of each compartment is achieved through the suction pump, and the pressure difference between each compartment is controlled to achieve overall horizontal adjustment of the offshore wind turbine foundation.

[0055] That is, when the fan foundation is installed, not only can the negative pressure in each compartment in the annular skirt 40 be achieved through the suction pump to achieve a reliable connection between the annular skirt 40 and the seabed, but the setting of multiple compartments can also prevent the occurrence of air leakage in a certain compartment affecting the installation stability of the fan foundation. In addition, the horizontal installation of the fan foundation can be achieved by adjusting the pressure difference between the compartments through the suction pump.

[0056] When the offshore wind turbine foundation is installed, fillers are filled from the opening of each compartment of the sliding base 20 into the hollow inner cavity of the sliding base 20, so that the sliding base 20 slides downward along the central column 10 and is supported on the fixed base 30. In other words, after the annular skirt 40 is stably combined with the seabed mud surface, the hollow inner cavity of the sliding base 20 is filled with concrete or other media, so that the sliding base 20 sinks into the fixed base 30, and at the same time, the sliding base 20 provides downward pressure to the annular skirt 40, further increasing the reliability of the installation and fixation of the wind turbine foundation.

[0057] Similarly, when in the installation state, concrete is injected through the first opening of each compartment of the fixed base 30 to fill the hollow inner cavity of the fixed base 30, further increasing the reliability of the installation and fixation of the wind turbine foundation.

[0058] In the above embodiments, one of the central column 10 and the sliding base 20 is provided with a groove, and the other is provided with a slider that slides in cooperation with the groove, and the groove is arranged along the axial direction; the number of the groove is at least one. The figure shows a specific implementation of providing a raised slider on the central column 10 and providing a groove on the sliding base 20. Of course, the central column 10 may also be provided with a groove, and the sliding base 20 may be provided with a slider.

[0059] The number of the raised sliding blocks may be two, or may be three or more, and the raised sliding blocks are evenly arranged along the circumferential direction.

[0060] For other structures of offshore wind turbine foundations, please refer to the existing technology, which will not be described in detail in this article.

[0061] The above is a detailed introduction to an offshore wind turbine foundation provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An offshore wind turbine foundation, characterized in that: The invention comprises a central column (10), a fixed base (30) and a sliding base (20); the fixed base (30) is fixed to the root section of the central column (10); an annular tube skirt (40) is fixed to the lower surface of the fixed base (30); the annular tube skirt (40) encloses a cavity with an opening facing downward; the interior of the cavity is divided by a partition to form a plurality of compartments; Both the fixed base (30) and the sliding base (20) are hollow concrete structures, and the hollow inner cavity of the fixed base (30) and the hollow inner cavity of the sliding base (20) are formed with a plurality of independent compartments; A through hole is provided in the middle of the sliding base (20), the central column (10) passes through and is located inside the through hole, the sliding base (20) is located above the fixed base (30), and the sliding base (20) is able to move axially relative to the central column (10); It also includes an adjustment device. During floating transportation, the hollow inner cavities of the sliding base (20) and the fixed base (30) are partially hollowed out to provide buoyancy; the adjustment device is used to adjust the amount of medium inside each compartment to maintain the overall center of gravity of the offshore wind turbine foundation stable during floating transportation; It also includes a filler, which is placed in each chamber of the sliding base (20) when fixedly installed, so that the sliding base (20) can slide axially to the installation position at the root of the central column (10) and provide downward pressure on the annular tube skirt (40); each of the chambers has an opening, and the regulating device includes a ballast system and a valve installed at each opening, the valve controls the opening to be opened or closed, and the valve opens or closes the opening according to the signal of the ballast system to pump in or out the medium of the corresponding chamber; the arrangement of the chambers inside the fixed base (30) and the sliding base (20) corresponds to the compartment arrangement position of the annular tube skirt (40); When in the installation state, each chamber of the fixed base (30) is also filled with concrete or fluid medium.

2. The offshore wind turbine foundation according to claim 1, characterized in that: The cavity of the annular skirt is provided with an annular partition (41) coaxial therewith, the annular partition (41) forming a central compartment (40a) inside, and further comprising a plurality of radial partitions (42), each of the radial partitions (42) being arranged between the annular partition (41) and the inner wall of the annular skirt (40) and uniformly distributed along the circumferential direction, so as to divide the annular skirt and the annular partition (41) into a plurality of peripheral compartments (40b).

3. The offshore wind turbine foundation according to claim 1, characterized in that: The compartments inside the annular tube skirt (40) are all provided with control ports for connecting to an external suction pump. Under normal circumstances, the control ports are in a closed state. During installation, negative pressure installation of each compartment is achieved through the suction pump, and the pressure difference between each compartment is controlled to achieve overall horizontal adjustment of the offshore wind turbine foundation.

4. The offshore wind turbine foundation according to claim 1, characterized in that: The filler is concrete or a fluid medium; when the offshore wind turbine foundation is installed, each compartment of the sliding base (20) is filled with the filler, so that the sliding base (20) slides downward along the central column (10) and is supported on the fixed base (30).

5. The offshore wind turbine foundation according to claim 1, characterized in that: The sliding base (20), the fixed base (30) and the annular tube skirt are all reinforced concrete bodies.

6. The offshore wind turbine foundation according to any one of claims 1 to 5, characterized in that: One of the central column (10) and the sliding base (20) is provided with a groove, and the other is provided with a sliding block that slides in cooperation with the groove, and the groove is arranged along the axial direction; the number of the groove is at least one.

7. A method for towing and installing an offshore wind turbine foundation according to any one of claims 1 to 6, characterized in that: Includes the following: Pre-assembling the tower, the wind turbine unit (50) and the offshore wind turbine foundation to form an integral structure, and placing it in the sea; During the towing process, the amount of medium in each compartment of the sliding base (20) and the fixed base (30) is adjusted to maintain the overall center of gravity of the offshore wind turbine foundation stable during floating transportation; After being towed to the installation location, the fixed base (30) is filled with a fluid medium or concrete. Under the action of its own weight, the fixed base (30) and the annular skirt (40) drive the central column (10) to sink to the mud surface of the seabed. The annular skirt (40) and the mud surface form a sealed environment. The seawater in the annular skirt (40) is pumped out through a suction pump skid system. The annular skirt (40) penetrates into the soil under the action of negative pressure until the top of the annular skirt (40) is in complete contact with the mud surface, thereby achieving a stable combination of the foundation and the seabed.

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