SEMI-SUBMERSIBLE FLOATING PLATFORM FOR OFFSHORE WIND TURBINE

Abstract

A semi-submersible floating platform including six columns (C.sub.V, C.sub.L) arranged forming a triangle such that three vertex columns (C.sub.V) are arranged at the vertices of the triangle. Three side columns (C.sub.L) are arranged at the centers of the sides of the triangle. Each column (C.sub.V, C.sub.L) is connected by a joining element (B) respective to each of the adjacent columns (C.sub.V, C.sub.L). Further, a side column (C.sub.L) is configured to support the wind turbine (A). The columns (C.sub.V, C.sub.L) that do not support the wind turbine (A) have a weight configured to maintain the center of mass of the set formed by the platform (1) and wind turbine (A) in the vertical of the hull center of the platform (1).

Claims

1. A semi-submersible floating platform for marine wind turbine comprising six columns arranged essentially forming a triangle such that three vertex columns are arranged at the vertices of the triangle and three side columns are arranged at the centers of the sides of the triangle, wherein each column is connected by a joining element respective to each of the adjacent columns, being adjacent to each vertex column the two side columns located on the sides that converge at said vertex, and being adjacent to each side column the two vertex columns belonging to said side and the remaining two side columns, wherein a side column is configured to support the wind turbine, and wherein those columns other than the side column configured to support the wind turbine have a weight configured to bring the center of mass of the set formed by the platform and wind turbine to the vertical of the hull center of the platform.

2. The semi-submersible floating platform according to claim 1, wherein the connections between the joining elements and the columns are located in a lower portion of the columns, so that the joining elements are immersed during the lifetime of the platform.

3. The semi-submersible floating platform according to claim 1, wherein the columns have the shape of a polygonal base prism such that each connection between a joining element and a column takes place perpendicular to a lateral side of said column.

4. The semi-submersible floating platform according to claim 3, wherein the triangle is equilateral and the columns have the shape of a hexagonal base prism.

5. The semi-submersible floating platform according to claim 1, wherein each joining element comprises a single arm having a rectangular-shaped cross section.

6. The semi-submersible floating platform according to claim 1, wherein an interior of at least one the joining element comprises a passageway configured for the passage of people between at least two of the columns.

7. The semi-submersible floating platform according to claim 1, wherein each of the columns has a height in the range of 10 and 15 meters.

8. The semi-submersible floating platform according to claim 1, wherein each of the joining elements has a length in the range of 20 and 40 meters.

9. The semi-submersible floating platform according to claim 1, wherein the columns other than the side column configured to support the wind turbine comprise ballast formed by technical water or sea water.

10. The semi-submersible floating platform according to claim 1, comprising an active ballast system.

11. The semi-submersible floating platform according to claim 1, further comprising heaving plates.

12. The semi-submersible floating platform according to claim 11, comprising inner heaving plates arranged between stretches of contiguous joining elements, wherein said stretches are adjacent to the column to which both joining elements are connected, and wherein said inner heavy plates do not extend outside the triangle of the platform.

13. The semi-submersible floating platform according to claim 12, wherein the inner heaving plates are triangular.

14. The semi-submersible floating platform according to claim 11, comprising outer heaving plates that protrude radially from the vertex columns essentially in all directions, so that at least a portion of said outer heaving plates extends outside the triangle of the platform.

15. The semi-submersible floating platform according to claim 14, wherein the outer heaving plates have a polygonal or circular shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0058] FIG. 1 shows a schematic view of the different types of floating platform currently known.

[0059] FIGS. 2A and 2B respectively show a plant and a elevation of an example of semi-submersible floating platform according to the present invention.

[0060] FIGS. 3A and 3B respectively show a plant and an elevation of another example of semi-submersible floating platform according to the present invention.

[0061] FIGS. 4A-4E show perspective views of examples of semi-submersible floating platform with different configurations of the heaving plates and the joining elements between the columns.

[0062] FIGS. 5A-5G show more perspective views of examples of a semi-submersible floating platform with different configurations of the heaving plates and the joining elements between the columns.

[0063] FIG. 6 shows a perspective view of the aspect of a semi-submersible floating platform according to the present invention already located in its final location and with the wind turbine assembled.

DETAILED DESCRIPTION

[0064] Examples of semi-submersible floating platforms (1) according to the present invention are described below with reference to the accompanying figures.

[0065] FIGS. 2A and 2B respectively show a plant and an elevation of an example of semi-submersible floating platform (1). As can be appreciated, the platform (1) has a structure formed by six columns (C.sub.V, C.sub.L) arranged so as to form an equilateral triangle. Three vertex columns (C.sub.V) are arranged at the vertices of the equilateral triangle, and three side columns (C.sub.L) are arranged at the center of the sides of the equilateral triangle. In this example, the columns (C.sub.V, C.sub.L) have hexagonal cross-section whose height is approximately 12 meters, although in general its height can be between approximately 10 meters and 15 meters for high-powered wind turbines (A).

[0066] In this triangular structure, the columns (C.sub.V, C.sub.L) adjacent to each other are connected by a set of nine joining elements (B) formed by straight arms of rectangular cross-section and whose longitudinal axes are contained in a plane perpendicular to the axis of the columns (C.sub.V, C.sub.L). In particular, for each vertex column (C.sub.V) only the two side columns (C.sub.L) located in the center of the sides that converge with the vertex of the triangle where said vertex column (CV) is located are considered adjacent. Therefore, in each vertex column (C.sub.V) two joining elements (B) converge that join it with two side columns (C.sub.L). In turn, for each side column (C.sub.L) the two vertex columns (C.sub.V) located at the ends of the side to which it belongs and the remaining two side columns (C.sub.L) of the structure are considered adjacent. That is, in each side column (C.sub.L) four joining elements (B) converge, of which two elements (B) join it with two vertex columns (C.sub.V) and two other elements (B) join it with two side columns (C.sub.L). The position of the columns (C.sub.V, C.sub.L) at the vertices and at the centers of the sides of the triangle ensures that all the joining elements (B) have the same length. In this example, each joining element (B) measures approximately 30 meters, although its length can be between 20 meters and 40 meters.

[0067] The connection point between the joining elements (B) and the columns (C.sub.V, C.sub.L) is located near the lower end of the columns (C.sub.V, C.sub.L). Thus, the joining elements (B) are below the water level when the platform (1) is in use, as shown in FIGS. 2B (the waterline is shown by dashed line). Furthermore, since the platform (1) as a whole has an equilateral triangle shape, an adequate orientation of the hexagonal columns (C.sub.V, C.sub.L) ensures that each and every one of the connections between columns (C.sub.V, C.sub.L) and joining elements (B) take place in perpendicular.

[0068] The side column (C.sub.L) located on the left side in FIG. 1 is configured to support the wind turbine (A). In this example, this mainly implies that on said side column (C.sub.L) a transition piece is arranged between the hexagonal shape of the upper end of the column and the circular shape of the base of the wind turbine tower (A). To prevent the platform (1) from inclining with the weight of the wind turbine (A), the three columns (C.sub.V, C.sub.L) thereof that do not belong to the side where the side column (C.sub.L) that the wind turbine (A) will support comprise a ballast. That is, each of the columns (C.sub.V, C.sub.L) that do not belong to the left side of the platform (1) according to the arrangement of FIG. 2A comprises a technical water tank whose volume is calculated to maintain the center of gravity of the set formed by the platform (1) and the wind turbine (A) in the vertical of the hull center of the platform (1), which in this example coincides with the barycenter of the triangle.

[0069] The platform (1) shown in FIGS. 2A and 2B further comprises a set of heaving plates (PI) contained in the plane of the joining elements (B). In particular, this example includes nine essentially triangular heaving plates (PI) that do not protrude outside the platform plant (1), and that are located between the sections of the joining elements (B) near the columns (C.sub.V, C.sub.L) in which they converge. In other words, each pair of contiguous joining elements (B) is joined by a heaving plate (PI) triangular in the zone near the column (C.sub.V, C.sub.L) where they converge, with the exception of the pairs of joining elements (B) that connect both side columns (C.sub.L).

[0070] The platform (1) shown in FIGS. 2A and 2B further comprises a set of heaving plates (P.sub.I) contained in the plane of the joining elements (B). In particular, this example includes nine essentially triangular heaving plates (P.sub.I) that do not protrude outside the platform plant (1), and that are located between the sections of the joining elements (B) near the columns (C.sub.V, C.sub.L) in which they converge. In other words, each pair of contiguous joining elements (B) is joined by a heaving plate (P.sub.I) triangular in the zone near the column (C.sub.V, C.sub.L) where they converge, with the exception of the pairs of joining elements (B) that connect both side columns (C.sub.L).

[0071] As mentioned earlier in this document, this platform (1) is very advantageous due to its high standardization capacity, both in terms of the elements that make it up and the manufacturing processes. The platform (1) is fundamentally formed by three identical elements that are repeated: columns (C.sub.V, C.sub.L), joining elements (B) and heaving plates (P.sub.I). In addition, the connections between joining elements (B) and columns (C.sub.V, C.sub.L) are all perpendicular. In any case, note that this is only an example, and that it is possible that the elements are not all equal according to the structural needs of the platform (1).

[0072] FIGS. 3A and 3B show another example of a platform similar to that shown in FIGS. 2A and 2B except that it further comprises heaving plates (P.sub.E) that protrude radially from the end of the lower end of each of the vertex columns (C.sub.V) of the platform (1), and that have a hexagonal shape similar to that of the columns (C.sub.V, C.sub.L) but of greater size. Each of these heaving plates (P.sub.E) has a discontinuity to allow the passage of a anchoring line of the platform (1).

[0073] FIGS. 4A to 4E show other examples of a platform (1) substantially the same as that shown in FIGS. 2 and 3 with the exception of the configuration of the heaving plates and the elements (B).

[0074] In FIG. 4A, the platform (1) has simple joining elements (B) formed by a single horizontal arm of rectangular cross-section whose lower surface essentially coincides with the surface of the lower end of the columns (C.sub.V, C.sub.L). This platform (1) has outer heaving plates (P.sub.E) located in the vertex columns (C.sub.V) and that protrude from the platform plant (1). Specifically, these are three heaving plates (P.sub.E) that protrude radially from the lower end of each of the vertex columns (C.sub.V) of the platform (1), and that have a hexagonal shape similar to that of the columns (C.sub.V, C.sub.L) but of greater size. This platform (1) also has internal heaving plates (P.sub.I) of a triangular shape that are arranged in the connection zones of each pair of joining elements (B) with the respective column (C.sub.V, C.sub.L).

[0075] In FIG. 4B, the platform (1) has simple joining elements (B) formed by a single horizontal arm of circular cross-section. The heaving plates are similar to those shown in FIGS. 3A and 3B, including inner heaving plates (P.sub.I) in the area where each pair of joining elements (B) join a column (C.sub.V, C.sub.L) and outer heaving plates (P.sub.E) of similar hexagonal shape that protrude from the vertex columns (C.sub.V) and provided with a discontinuity to allow the passage of a anchoring line of the platform (1).

[0076] The arrangement of FIG. 4C is similar to that of FIG. 4A, although with diagonal reinforcements in shape of a bracket in the connection zones between the joining elements (B) and the columns (C.sub.V, C.sub.L). The configuration of FIG. 4D is similar to that of FIG. 4C, although the diagonal reinforcements are formed by inclined bars. FIG. 4E shows a configuration where the joining elements are lattices comprising two parallel bars that connect the columns respectively in two planes located near the lower end and the upper end of the columns.

[0077] FIGS. 5A-5F shows another set of different platform configurations (1) according to the invention with regard to the heaving plates (P.sub.I, P.sub.E) and the cross-section of the joining elements (B). As can be seen in these figures, it is possible to combine internal heaving plates (P.sub.I) that do not protrude from the platform plant (1), such as those shown in FIGS. 2A and 2B, and outer heaving plates (P.sub.E) that protrude from it, such as those shown in FIGS. 3 and 4, according to different configurations. It is also possible to use non-cylindrical joining elements (B), such as, for example, joining elements of square cross-section or in H- or double T-shape.

[0078] Finally, FIG. 6 shows the aspect of a wind turbine (A) supported by the platform (1) of the invention already installed in its final position.

[0079] Additional implementations are disclosed in the following clauses.

[0080] Clause 1: Semi-submersible floating platform for marine wind turbine comprising six columns (CV, CL) arranged essentially forming a triangle such that three vertex columns (CV) are arranged at the vertices of the triangle and three side columns (CL) are arranged at the centers of the sides of the triangle, [0081] wherein each column (CV, CL) is connected by a joining element (B) respective to each of the adjacent columns (CV, CL), being adjacent to each vertex column (CV) the two side columns (CL) located on the sides that converge at said vertex, and being adjacent to each side column (CL) the two vertex columns (CV) belonging to said side and the remaining two side columns (CL), [0082] wherein a side column (C.sub.L) is configured to support the wind turbine (A), and [0083] wherein those columns (C.sub.V, C.sub.L) other than the side column (C.sub.L) configured to support the wind turbine (A) have a weight configured to bring the center of mass of the set formed by the platform (1) and wind turbine (A) to the vertical of the hull center of the platform (1).

[0084] Clause 2: Floating platform (1) according to clause 1, wherein the connections between the joining elements (B) and the columns (C.sub.V, C.sub.L) are located in a lower portion of the columns (C.sub.V, C.sub.L), so that the joining elements (B) are immersed during the lifetime of the platform (1).

[0085] Clause 3: Floating platform (1) according to any one of the preceding clauses, wherein the columns (C.sub.V, C.sub.L) have the shape of a polygonal base prism such that each connection between a joining element (B) and a column (C.sub.V, C.sub.L) takes place perpendicular to a lateral side of said column (C.sub.V, C.sub.L).

[0086] Clause 4: Floating platform (1) according to clause 3, wherein the triangle is equilateral and the columns (C.sub.V, C.sub.L) have the shape of a hexagonal base prism.

[0087] Clause 5: Floating platform (1) according to any one of the preceding clauses, wherein each joining element (B) comprises a single arm having a rectangular-shaped cross section.

[0088] Clause 6: Floating platform (1) according to any one of the preceding clauses, wherein the interior of the joining elements (B) comprises passageways configured for the passage of people between some columns (C.sub.V, C.sub.L) and others.

[0089] Clause 7: Floating platform (1) according to any one of the preceding clauses, wherein the columns (C.sub.V, C.sub.L) have a height of between 10 and 15 meters.

[0090] Clause 8: Floating platform (1) according to any one of the preceding clauses, wherein the joining elements (B) have a length of between 20 and 40 meters.

[0091] Clause 9: Floating platform (1) according to any one of the preceding clauses, wherein the columns (CV, CL) other than the side column (CL) configured to support the wind turbine (A) comprise ballast formed by technical water or sea water.

[0092] Clause 10: Floating platform (1) according to any one of the preceding clauses, comprising an active ballast system.

[0093] Clause 11: Floating platform (1) according to any one of the preceding clauses, further comprising heavy plates (P.sub.E, P.sub.I).

[0094] Clause 12: Floating platform (1) according to clause 11, comprising inner heaving plates (P.sub.I) arranged between stretches of contiguous joining elements (B), wherein said stretches are adjacent to the column (C.sub.V, C.sub.L) to which both joining elements (B) are connected, and wherein said inner heaving plates (P.sub.I) do not extend outside the triangle of the platform (1).

[0095] Clause 13: Floating platform (1) according to clause 12, wherein the inner heaving plates (P.sub.I) are triangular.

[0096] Clause 14: Floating platform (1) according to any one of clauses 11-13, comprising outer heaving plates (P.sub.E) that protrude radially from the vertex columns (C.sub.V) essentially in all directions, so that at least a portion of said outer heaving plates (P.sub.E) extends outside the triangle of the platform.

[0097] Clause 15: Floating platform (1) according to clause 14, wherein the outer heaving plates (P.sub.E) have a polygonal or circular shape.