Floating reinforced concrete platform applicable to the marine wind power sector industry

Abstract

The present invention relates to a solution for a floating wind platform made of reinforced concrete for mass production, characterized by a geometric design providing a hydrostatic natural prestressing to the concrete, causing it to work under compression. The structural response of the platform for working in the most effective mode is improved, and the occurrence of fractures or cracks in the concrete is prevented, which reduces permeability and allows for reducing the rebar to be contained in the structure, also increasing operational safety. Furthermore, the invention has a system for anchoring the mooring lines to the structure in the form of a truss made of reinforced concrete which evenly distributes mooring stresses, minimizing prestressing in the high area of the platform, and increasing the area for distributing shear forces due to the change in section between the platform and the tower of the wind turbine. The geometric design furthermore confers the versatility of being able to adopt low draft SPAR, semi-submersible, barge, or buoy solutions, with the wind turbine being installed such that it is centered or off-center on the structure, thereby being adapted to different draft requirements or environmental and logistics conditions.

Claims

1. A floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine, characterized by: a) a lower body consisting of a planar base made of reinforced concrete; b) a single intermediate body made of reinforced concrete formed by a vertical extrusion with a horizontal section consisting of an arrangement of at least five adjacent quasi-circles with a straight contacting segment between same and arranged in a staggered manner; with the inside of each quasi-circle being a leak-tight space and the inner spaces of every three quasi-circles being hollow spaces and directly connected with the sea; c) an upper body on the intermediate body formed by at least one tower which is a prolongation of a quasi-circle and serves as a support for the wind turbine; d) a mooring system by means of lines connecting the platform to the sea floor.

2. The floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine according to claim 1, characterized in that the enclosures of the intermediate body are domes and wherein each dome is arranged on each of the quasi-circles forming the section of the intermediate body made of reinforced concrete.

3. The floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine according to claim 1, characterized in that the enclosures of the intermediate body are reinforced planar slabs or plates and wherein each reinforced slab or plate is arranged on each of the quasi-circles forming the section of the intermediate body made of reinforced concrete.

4. The floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine according to claim 1, wherein some of the inner leak-tight spaces of each quasi-circle have the capacity to house a combination of a solid and liquid ballast and air.

5. The floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine according to claim 3, wherein some of the inner leak-tight spaces of each quasi-circle have the capacity to house a combination of solid and liquid ballast and air.

6. The floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine according to claim 4, wherein the mooring system is characterized by: a) a plane truss made of prestressed concrete, located between the intermediate concrete body and the enclosures in the form of a dome and consisting of at least three longitudinal elements arranged in a triangular shape and located such that the vertexes of the mentioned truss are located on the straight contacting segments between the quasi-circles forming the section of the intermediate body of the platform; b) wherein the mooring lines are secured on the straight contacting segments between the quasi-circles forming the section of the intermediate body of the platform in the highest area thereof, with there being structural continuity between the plane truss made of prestressed concrete and the mentioned mooring lines.

7. The floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine according to claim 4, wherein the mooring system is characterized by mooring lines which are secured on reinforced plates located between the intermediate concrete body and the enclosures in the form of a dome.

8. The floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine according to claim 5, wherein the mooring system is characterized by mooring lines which are secured on the planar enclosures.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] To complement the description that is being made and for the purpose of helping to better understand the features of the invention, a set of drawings is attached as an integral part of said description in which the following is depicted in an illustrative and non-limiting manner:

[0038] FIG. 1 shows a schematic depiction of the problem caused by the loads produced by wind on the floating platform, in which a high concentration of forces occurs in the area where the tower of the wind turbine intersects the concrete body of the platform, where the area of the horizontal section changes abruptly.

[0039] FIG. 2 shows an elevational view of one of the possible configurations of the floating platform defined herein, in which the three bodies, that is, lower body (1), intermediate body (2), and upper body (3), made of concrete and forming the platform can be seen. In this case, the upper body (3) is formed by a single tower (4) and the enclosures (5) consist of domes.

[0040] FIG. 3 shows a section view in which there can be seen the quasi-circles (6), arranged adjacently in a staggered manner with a straight contacting segment between same, the vertical extrusion of which forms the intermediate body (2) of the platform. This figure shows one of the possible configurations of these quasi-circles (6), in which the openings (7) existing between every three quasi-circular sections can be seen.

[0041] FIG. 4 shows a schematic depiction of the arrangement of the planar latticework (9) made of prestressed concrete, in one of the possible configurations that can be obtained from the platform. The manner in which this planar latticework (9) distributes stresses coming from the mooring lines (10) over the intermediate concrete body (2) of the platform is shown.

[0042] FIG. 5 shows another possible configuration that the platform can adopt by adding more quasi-circles (6) in the horizontal section forming the intermediate concrete body (2) of the platform. The manner in which the planar latticework (9) made of prestressed concrete can be adapted to variations in the geometry of the platform and the manner in which the mooring lines (10) can be arranged such that loads are transmitted to the planar latticework (9) in any variation in the geometry of the platform are also shown.

[0043] FIG. 6 shows a profile view of one of the possible configurations, in this case a semi-submersible type of configuration, of the floating platform defined in this patent. The figure shows how various towers (4), including the one supporting the tower of the wind turbine, are located above the surface of the water (11), thereby providing to the platform the inertia needed to be stable during the installation and operating phases.

PREFERRED EMBODIMENT OF THE INVENTION

[0044] Therefore, an object of the present invention is to provide a solution for a floating wind platform made of reinforced concrete for mass production and characterized by a geometric design providing a hydrostatic natural prestressing to the concrete, causing it to operate in its most effective mode, i.e., under compression, improving the structural response of the platform and preventing the occurrence of fractures or cracks in the concrete, which reduces permeability and allows for reducing the framework to be contained in the structure, also increasing operational safety. The present invention has a system for anchoring the mooring lines to the structure in the form of a latticework made of reinforced concrete which evenly distributes mooring stresses, minimizing prestressing in the high area of the platform, and increasing the area for distributing shear forces due to the change in section between the platform and the tower of the wind turbine. The geometric design furthermore confers the versatility of being able to adopt low draft SPAR, semi-submersible, barge, or buoy solutions, with the wind turbine being installed such that it is centered or off-center on the structure, thereby being adapted to different draft requirements or environmental and logistics conditions.

[0045] The present invention consists of a floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine in which three parts are distinguished (FIG. 2): a lower body (1), an intermediate body (2), and an upper body (3) on which a single offshore wind turbine is arranged. The platform has a spread moored type mooring system (FIG. 4) made up of at least three lines (10), arranged spaced apart as equally as possible.

[0046] The lower body (1) of the floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine (FIG. 2) consists of a planar concrete base the objective of which is to provide structural support to the rest of the platform which is supported on said body, and also to contribute low weight to the platform, thereby improving stability thereof.

[0047] The intermediate body (2) of the floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine consists of a single concrete body formed as a vertical extrusion with a horizontal section (FIG. 3) consisting of a staggered arrangement of at least five adjacent quasi-circles (6) with a straight contacting segment between same. The inner space (8) of each quasi-circle is a leak-tight space capable of housing a combination of solid and liquid ballast.

[0048] In the arrangement of the intermediate body (2) described above (FIG. 3), there are a series of inner openings (7) formed by every three quasi-circles (6) contacting one another. Said inner openings (7) are open at the upper area of the platform and communicated with the outside through their lower part. The purpose of said openings (7) is to remain filled, as a result of their connections with the outside, in a manner that is consistent with the draft the platform has at all times. Equilibrium of the hydrostatic pressures to which the platform is subjected when it is partially or completely submersed is thereby achieved. As a result of this equilibrium of pressures, the concrete walls forming the intermediate body (2) of the platform (FIG. 2) thereby naturally adapt to certain compression prestressing as a result of the mentioned pressures, favoring the good structural behavior thereof.

[0049] The upper body (3) of the floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine (FIG. 2) of the present invention is arranged on the intermediate body (2) described above and consists of a series of enclosures such that each enclosure is arranged on each quasi-circle (6) forming the horizontal section of the intermediate body (2) in the highest section of said body (2), with the exception of at least one of said sections (6), on which a prolongation of said section is arranged to form a tower (4) that is raised above the rest of the platform, and on which the support for the wind turbine of the platform will be arranged.

[0050] The geometry of the enclosures (5) existing on the intermediate body (2) (FIG. 2) is different depending on the platform concept provided in relation to the degree of submersion thereof, as discussed above.

[0051] On one hand, the floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine is capable of operating when submersed, with only part of the towers (4), where one supports the wind turbine if there is more than one tower (4), and the wind turbine itself being located above the surface of the sea (11) (FIG. 6). In this situation, the stability of the platform is largely obtained as a result of the concrete base forming the lower body (1) of the platform, which keeps the center of gravity of the rig as low as possible. In this configuration, the enclosures (5) of the intermediate concrete body (2) consist of a series of domes arranged on each quasi-circle forming the section of the intermediate body (2) of the platform, with the exception of those quasi-circles (6) on which the towers (4) are arranged (FIG. 6). The purpose of these domes is to receive the hydrostatic pressure to which they are subjected when the platform is submersed and to transmit the loads produced by said pressures to the intermediate body (2) such that said body works under compression against these loads.

[0052] On the other hand, the floating platform made of concrete applicable to the offshore wind industry for supporting a wind turbine is capable of operating such that not the entire intermediate body (2) is submersed, but rather part of same is located above the surface of the sea. For this platform configuration, the enclosures (5) that are arranged on the intermediate body (FIG. 2) simply consist of reinforced slabs or plates, since construction-wise, it is the simplest solution, and these elements are reasonable as they are not exposed to hydrostatic pressure as they are above the water line. These enclosures (5) are arranged on each quasi-circle forming the section of the intermediate body of the platform, with the exception of the towers (FIG. 6).

[0053] The actual geometry of the intermediate concrete body (2) (FIG. 2) of the floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine allows a number of different platform concepts to be configured according to whether more or fewer quasi-circles (6) are arranged in the horizontal section (FIG. 3) forming the intermediate body (2), keeping the minimum number of these quasi-circles (6) at five, as described above. These variations, together with variations in the arrangement of towers (4) (FIG. 6) forming the upper body (3) (FIG. 2), both in number, with there being at least one, and in position in the platform, allows a wide range of platform concepts to be obtained, such as: platforms with a single tower, in which the water-plane area is relatively small and scarcely contributes to the stability of the rig since said stability is achieved by keeping the center of gravity very low, and platforms in which there is more than one tower (4) in the upper body, where one supports the wind turbine, and they are spaced out from one another to assure such an inertia of the water-plane area that is favorable to the stability of the rig assembly.

[0054] The floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine of the present invention further consists (FIG. 4) of a planar latticework (9) made of prestressed concrete which is arranged between the intermediate body (2) and the upper body (3) of the platform (FIG. 2). Said planar latticework (9) consists of at least three longitudinal elements made of prestressed concrete arranged in a triangular shape and located such that the vertexes of the triangular geometry are located in areas with straight contacting segments between the quasi-circular sections (6) forming the intermediate body (2) of the platform (FIG. 3). The mooring lines (10) of the floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine (FIG. 4) are secured on the straight contacting segments between quasi-circles (6) forming the section of the intermediate body (2) of the platform in the highest area thereof, such that there is structural continuity between mooring lines (10) and the vertexes of the planar latticework (9) made of prestressed concrete.

[0055] The actual configuration of the planar latticework (9) made of prestressed concrete allows being adaptable to the geometry of the floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine depending on the number of quasi-circles (6) existing in the section of the intermediate concrete body (2) (FIG. 5), such that by adding longitudinal elements made of prestressed concrete, a latticework (9) can be formed from several of these longitudinal elements arranged in a triangular shape. This feature confers certain versatility to the mentioned latticework (9) that renders it suitable for any of the possible configurations that the floating platform made of reinforced concrete applicable to the offshore wind industry for supporting a wind turbine of the present invention can adopt.

[0056] The invention has been described in reference to specific cases without departing from the general scope of the invention as defined in the attached claims. For this reason, the specification and, therefore, the drawings are neither restrictive nor limiting and must be understood as an example.