Hollow structural element of a wind energy plant

Abstract

A hollow structural element of a wind energy plant, in particular an offshore wind energy plant which includes a hollow structural element, and a cable arrangement extending along the hollow structural element. A shading element is arranged on the hollow structural element at a distance from the cable arrangement.

Claims

1. Hollow structural element of a wind energy plant comprising: a hollow structural element, and a cable arrangement extending along the hollow structural element, wherein a shading element is arranged at the hollow structural element at a distance from the cable arrangement, a clear width between the hollow structural element and the shading element varies along an arc section, and the clear width in a central region of the arc section is smaller than the clear width at at least one outer edge of the arc section.

2. Hollow structural element according to claim 1, wherein the shading element is arc-shaped, wherein the shading element has a curvature or the shading element has at least one circular arc or the shading element is straight or the shading element is formed from at least two straight sections running at an angle to one another, wherein the angle between the straight sections encompasses the hollow structural element.

3. Hollow structural element according to claim 1, wherein the shading element is arranged along an arc section around the hollow structural element, wherein the arc section spans at least one of an arc angle of at least 45°, an arc angle of at least 120°, an arc angle of at least 240°, an arc angle between 90° and 150° or an arc angle between 110° and 130°.

4. Hollow structural element according to claim 1, wherein the shading element is arranged at an outer lateral surface of the hollow structural element and/or the shading element is fastened to the hollow structural element with spacers.

5. Hollow structural element of a wind energy plant comprising: a hollow structural element, and a cable arrangement extending along the hollow structural element, wherein a shading element is arranged at the hollow structural element at a distance from the cable arrangement, wherein the hollow structural element comprises a monopile or a transition piece or is a J-tube.

6. Hollow structural element according to claim 5, wherein the shading element is arranged at the monopile or at the transition piece.

7. Hollow structural element according to claim 1, wherein the shading element projects beyond the hollow structural element in a collar-shape, the shading element projects beyond the hollow structural element radially outwardly, in the region of a platform, and/or the shading element is inclined in the direction of the hollow structural element.

8. Hollow structural element according to claim 1, wherein the shading element is arranged on the south side of the hollow structural element in the installed state, and/or the shading element is perforated and/or the shading element is slotted and/or the shading element is round perforated.

9. Hollow structural element of a wind energy plant comprising: a hollow structural element, and a cable arrangement extending along the hollow structural element, wherein a shading element is arranged at the hollow structural element at a distance from the cable arrangement, wherein the shading element is at least in parts convexly shaped along the arc section on the side facing the hollow structural element and/or the shading element is convexly shaped in the region of at least one outer edge of the arc section on the side facing the hollow structural element.

10. Hollow structural element according to claim 1, wherein the shading element is arranged on the hollow structural element in such a way that, in the installed state of the hollow structural element, the shading element is arranged on the hollow structural element at a distance in the longitudinal direction from a platform and/or the shading element is arranged on the hollow structural element at a distance in the longitudinal direction from a platform wherein the distance is chosen as a function of a latitude of an assembly position of the hollow structural element.

11. Hollow structural element according to claim 1, wherein the cable arrangement is guided within the hollow structural element and/or between the hollow structural element and the shading element.

12. Hollow structural element according to claim 1, wherein the shading element is formed from a metal sheet.

13. Hollow structural element according to claim 1, wherein the hollow structural element is tubular.

14. Wind energy plant, wherein the wind energy plant is an offshore wind energy plant comprising a hollow structural element according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, the subject matter is explained in more detail with reference to a drawing showing exemplary embodiments. In the drawing show:

(2) FIG. 1a, b hollow structural elements with cable arrangements;

(3) FIG. 2a a hollow structural element with a shading element according to an embodiment;

(4) FIG. 2b a hollow structural element with a shading element according to an embodiment;

(5) FIG. 2c a hollow structural element with a shading element according to an embodiment;

(6) FIGS. 3a-d various arrangements of shading elements;

(7) FIG. 4a, b views of shading elements;

(8) FIG. 5a, b shading element with different flow contours.

DETAILED DESCRIPTION OF THE INVENTION

(9) FIG. 1 shows a hollow structural element 2 of a wind energy plant. The hollow structural element 2 is formed from a monopile 2a and a transition piece 2b as a foundation structure.

(10) The monopile 2a is founded on the seabed 4 and protrudes from the water surface 6.

(11) The monopile 2a is rammed into the seabed 4. The dimension of the monopile 2a may change thereby. In order to obtain defined connection points for a tower of the wind energy plant, the transition piece 2b is placed onto the monopile 2a. The transition piece 2b may have an airtight deck 8 in its interior. The airtight deck 8 may be understood as a platform. Also, a circumferential, externally arranged platform 10 may be arranged on the transition piece 2b. The platform 10 may be formed as a landing platform. This construction of a hollow structural element 2 is sufficiently known.

(12) A cable arrangement 12 may be formed of one or more cables, each having an insulator and a cable core formed of an electrical conductor. The cables may be guided in the cable arrangement 12 in a common sheath, in particular a common insulation.

(13) In FIG. 1a, it is shown that the cable arrangement 12 is guided below the water surface 6 into the interior of the hollow structural element 2 and is guided inside the hollow structural element 2 up to the airtight deck 8. Originating from the airtight deck 8, an electrical contacting of the cables of the cable arrangement 12 is realized a manner in itself known with power electronics known by themselves.

(14) Via the cables of the cable arrangement 12, the electrical energy generated by the wind energy plant 2 is transported to a power supply network. In the process, considerable electrical power flows through the cables of the cable arrangement 12. The resulting high currents cause joule losses, which are proportional to the ohmic resistance of the respective conductors. To reduce the ohmic resistance, the conductor cross sections are selected to be large.

(15) The resulting ohmic losses would have to be dissipated to the environment via convection to prevent the cable arrangement 12 from heating up so strongly as to cause damage.

(16) However, between the water surface 6 and the airtight deck 8, air exchange within the hollow structural element 2 is severely restricted, if not eliminated. As a result, the interior of the hollow structural element 2 heats up and the ohmic losses within the cables of the cable arrangement 12 can no longer be dissipated well.

(17) If, at times of strong wind, large electrical powers are transported via the cable arrangement 12, the cables of the cable arrangement 12 heat up particularly strongly. If there is then also strong solar radiation on the hollow structural element 2, the interior of the hollow structural element 2 between the water surface 6 and the airtight deck 8 heats up considerably. Such extreme conditions, too, must be taken into account when dimensioning the conductor cross-sections of the cables of the cable arrangement 12.

(18) In order to be able to dimension the conductor cross sections smaller, it is proposed to shade the hollow structural element 2, as will be shown below.

(19) FIG. 1b shows a hollow structural element 2c, which is formed as a J-tube. In contrast to FIG. 1a, in FIG. 1b the cable arrangement 12 is guided in the J-tube outside the foundation structure. The J-tube also completely encloses the cable arrangement 12, so that, similar to what was described previously, considerable heat generation inside the J-tube can result. If there is direct sunlight onto the J-Tubes, significant temperatures arise within the cables of the cable arrangement 12. Here as well, a shading is also proposed as described below. The hollow structural element 2c may also be guided (not shown) within the monopile 2a and/or within the transition piece 2b.

(20) FIG. 2a shows a hollow structural element 2 corresponding to FIG. 1a. The cable arrangement 12 is shown in FIG. 2a according to FIGS. 1a and 1n FIG. 2b according to FIG. 1b.

(21) To avoid solar radiation, especially when the sun is near its zenith, a shading element 14 is proposed. The shading element 14 may be attached to the hollow structural element 2 by spacers 16. The cable arrangement 12 may be guided within the hollow structural element 2. The cable arrangement 12 may also, as shown in FIG. 2b, be arranged on the outside of the foundation structure 2a,b on the J-tube formed as the hollow structural element 2 c. In this case, the cable arrangement 12 may be arranged with a clear width between the shading element 14 and the outer lateral surface of the foundation structure.

(22) If the sun is close to its zenith, it radiates at an angle α onto the hollow structural element 2. Due to the outwardly projecting platform 10, an area between the platform 10 and the upper edge of the shading element 14 is already shaded. At this distance along the longitudinal axis X of the hollow structural element 2, the shading element 14 may be spaced apart from that of the platform 10. The shading element 14 causes the interior of the hollow structural element 2 to heat up less, so that the conductor cross-sections of the cables of the cable arrangement 12 can be reduced compared to conventional arrangements.

(23) FIG. 2b shows another possibility of arranging the shading element 14 directly on the platform 10. The shading element 14 may face radially outwardly away from the platform 10. It is also possible for the shading element 14 to be angled downward. The length of the projection, as well as the angle of inclination, may be selected such that the shading element 14 causes shading of the entire hollow structural element 2 substantially down to the water surface 6. The cable arrangement 12 is shaded by the shading element 14. The cable arrangement 12 may also be arranged in the hollow structural element 2 as shown in FIG. 2a.

(24) FIG. 2c shows an arrangement of a hollow structural element 2c as a J-tube at the outside of the monopile 2a and/or the transition piece 2b. On the J-tube, the shading element 14 is arranged directly by webs 16. The shading of the cable arrangement 12 happens as described in FIGS. 2a, b. The elements of FIGS. 2a-c may be freely combined with each other. The foundation structure according to FIG. 2c may also be a non-hollow element, e.g. a foundation. The structures according to FIGS. 2a-c are in particular offshore structures.

(25) In the following, the hollow structural element 2 is described as representative of the J-tube 2c or the monopile 2a and/or of the transition piece 2b.

(26) FIGS. 3a-d show a section through the hollow structural element 2 and the shading element 14 transverse to the longitudinal axis X, in particular perpendicular thereto.

(27) In FIG. 3a, it may be seen that the hollow structural element 2 is tubular. Spaced apart from the hollow structural element 2, the shading element 14 is stretched in an arc segment with an arc angle β. The radius to a center point 2c of the shading element 14 is larger than the radius of the hollow structural element 2.

(28) The shading element 14 is attached to the hollow structural element 2 via spacers 16 in a distanced fashion.

(29) In particular, the shading element 14 is oriented toward the south in the northern celestial sphere, whereas it is oriented toward the north in the southern celestial sphere. The shading element 14 shown in FIG. 3a is arc-shaped.

(30) FIG. 3b shows another shading element 14 which is shaped straight, wherein the shading element 14 also spans an arc angle 3.

(31) In FIG. 3c, a shading element 14 is formed of two straight structural elements, oriented at an angle γ to each other. The legs of the shading element 14 partially embrace the hollow structural element 2.

(32) FIG. 3d shows an embodiment in which the shading element 14 is arranged completely circumferentially around the hollow structural element 2.

(33) As already explained, the shading element 14 may be formed of a metal sheet and may be perforated. FIG. 4a shows a shading element 14 with slots 14a. FIG. 4b shows a shading element with holes 14b. The slots 14a and/or the holes 14b provide a good ventilation in the space between the hollow structural element 2 and the shading element 14.

(34) The shading element 14 may be formed in a profiled manner, in particular profiled such that a distance between the shading element 14 and the hollow structural element 2 varies along the arc angle 3. A possible embodiment is shown in FIG. 5a. Here, the surface of the shading element 15 facing the hollow structural element 2 is convexly shaped so that a distance 20 between the hollow structural element 2 and the shading element 14 varies. Shown is that the distance 20 is smaller in a center region than in an edge region.

(35) FIG. 5b shows a shading element 14 which is formed in the manner of a wing in its edge regions 22. It can be seen that in the edge region 22, the distance 20 between the shading element 14 and the hollow structural element 2 varies, wherein a greater distance is initially given, it becomes smaller due to the convex shape and becomes greater again towards the central region of the shading element 14.

(36) Due to the two profilings as shown in FIGS. 5a and b, the cooling effect of the circulating air between the hollow structural element 2 and the shading element 14 is increased, since the flow velocities of passing air are increased.

REFERENCE LIST

(37) 2 Hollow structural element 2a Monopile 2b Transition Piece 2c J-Tube 2c Center point 4 Seabed 6 Water surface 8 Airtight deck 10 Platform 12 Cable arrangement 14 Shading element 14a Slot 14b Hole 16 Spacer 18 Area 20 Space 22 Edge area

(38) All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

(39) The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

(40) Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.