HEATING ELEMENT FOR A WIND TURBINE ROTOR BLADE

Abstract

A heating element for a wind turbine rotor blade including: two electrical connectors adapted to be connected to electrical supply lines of the wind turbine rotor blade, and a defined geometry configured to be arranged on a specified surface area of the wind turbine rotor blade. The heating element is provided with a position indicator adapted to be aligned with a leading edge of the wind turbine rotor blade.

Claims

1. A heating element for a wind turbine rotor blade, the heating element comprising: two electrical connectors configured to be connected to electrical supply lines of the wind turbine rotor blade; a defined geometry configured to be arranged on a specified surface area of the wind turbine rotor blade; and, said heating element being provided with a position indicator configured to be aligned with a leading edge of the wind turbine rotor blade.

2. The heating element of claim 1 further comprising a heating layer made of a carbon fiber material.

3. The heating element of claim 1, wherein said heating element includes a carrier layer and a heating conductor fastened to said carrier layer.

4. The heating element of claim 3, wherein said carrier layer includes a fiber mesh.

5. The heating element of claim 3, wherein said heating conductor is mounted to said carrier layer by stitching.

6. The heating element of claim 1, wherein said position indicator includes a yarn connected to said heating element by stitching.

7. The heating element of claim 6, wherein said position indicator includes a plurality of stitched yarn lines arranged in parallel.

8. The heating element of claim 7, wherein said plurality of stitched yarn lines together form a strip having a width which is less than a mesh size of said fiber mesh; and, said strip in a direction of said width is arranged within a single mesh.

9. The heating element of claim 6, wherein said yarn of said position indicator has a color which is different from at least one of a color of said carrier layer, a color of said heating conductor, and a color of any other yarns used on said heating element.

10. The heating element of claim 1, wherein said heating element has a length and a width; said two electrical connectors are arranged near opposite edges of said heating element running in a width direction; and, said position indicator indicates a line in the width direction.

11. The heating element of claim 10, wherein the line indicated by said position indicator is arranged at a predetermined length position.

12. The heating element of claim 3, wherein said heating conductor includes a metal heating wire.

13. The heating element of claim 3, wherein said heating conductor includes a bundle of carbon fibers.

14. The heating element of claim 4, wherein said fiber mesh has a mesh size in a range of 1 millimeter to 10 millimeters.

15. A heating system comprising: a set of heating elements; each heating element of said set of heating elements including two electrical connectors configured to be connected to electrical supply lines of a wind turbine rotor blade, each heating element of said set of heating elements further including a defined geometry configured to be arranged on a specified surface area of the wind turbine rotor blade; each of said heating element being provided with a position indicator configured to be aligned with a leading edge of the wind turbine rotor blade; and, each of said heating elements being configured to be placed on the wind turbine rotor blade side by side, wherein at least some of said geometries of said heating elements are different from one another.

16. A wind turbine rotor blade comprising: a wind turbine rotor blade body having an outer surface and a leading edge; a heating system including a set of heating elements; each heating element of said set of heating elements including two electrical connectors configured to be connected to electrical supply lines of the wind turbine rotor blade, each heating element of said set of heating elements further including a defined geometry configured to be arranged on a specified surface area of said wind turbine rotor blade body; each of said heating element being provided with a position indicator; each of said heating elements being configured to be placed on said wind turbine rotor blade body side by side, wherein at least some of said geometries of said heating elements are different from one another; and, each heating element of said set of heating elements being installed on said outer surface such that said position indicator is aligned with said leading edge.

Description

DETAILED DESCRIPTION

[0038] The heating element 10 of FIG. 1 has a geometry defined by a width 12 and a length 14. Two electrical connectors 16 are arranged near opposite edges 18 of the heating element 10 running in the width direction. Along the length direction, the heating element 10 has two longitudinal edges 26.

[0039] The heating element 10 includes a carrier layer 20 having the defined geometry and a heating conductor 22 fastened to the carrier layer 20. The heating conductor 22 is arranged in a meandering pattern on the carrier layer 20 so that when the heating element 10 is mounted to a wind turbine rotor blade, substantially the entire surface area of the wind turbine rotor blade covered by the heating element 10 is provided with adequate heating power.

[0040] The heating element 10 further includes a position indicator 24 which forms a line over the width of the heating element 10. The line is arranged in the width direction.

[0041] The heating conductor 22 is formed by a metal heating wire. Each of the two ends of the heating conductor 22 are provided with one of the electrical connectors 16.

[0042] Further details of the heating element 10 will be explained with reference to the enlarged sections shown in FIGS. 2 and 3. In FIG. 2, one can see the heating conductor 22 is fastened to a carrier layer 20 by various stitches 28 carried out with a first yarn. The position indicator 24 includes a plurality of stitched yarn lines 30 arranged in parallel. These stitched yarn lines are carried out with a second yarn having a different color than the first yarn. The second color also differs from a color of the heating conductor 22 and from a color of the carrier layer 20. Carrying out the stitching of the yarn lines 30 does not interfere with stitching of the heating conductor 22 to the carrier layer 20. The yarn lines 30 may be stitched before or after the heating conductor 22 is fastened to the carrier layer 20.

[0043] The further enlargement shown in FIG. 3 shows the internal structure of the carrier layer 20 which is formed by a fiber mesh of glass fibers 32 arranged in a rectangular pattern. A mesh size 34 of the fiber mesh is about 5 mm. One can see that all of the plurality of stitched yarn lines 30 are placed within one mesh. In other words, the plurality of stitched yarn lines 30 together form a strip having a width which is equal to or less than the mesh size 34.

[0044] The wind turbine rotor blade 36 shown in FIG. 4 has a blade root 38, a blade tip 40, a trailing edge 42 and a leading edge 44. Along a section of the leading edge 44, which section extends from near the blade tip 40 towards a central point nearer to the blade root over a substantial part of the wind turbine rotor blade length, a heating system 46 including a plurality of heating elements 10 is arranged. The heating elements 10 are arranged side-by-side. The heating elements 10 are connected via the electrical connectors 16 (not shown in FIG. 4) to first and second supply lines 48 running along the wind turbine rotor blade length and ending at the blade root 38.

[0045] FIG. 5 shows a section of a wind turbine rotor blade 36 in a schematic view on the leading edge 44, whereas two half shells 50, 52 are shown unfolded so that one can appreciate the arrangement of the heating elements 10. One can also see that the heating elements 10 have different geometries, each being approximately rectangular, and that the heating elements 10 are arranged side-by-side, with the longitudinal edges 26 of neighboring heating elements 10 abutting one another.

[0046] The enlarged view of FIG. 6 shows the heating element 10 arranged closest to the blade tip 40 in greater detail. One can see the carrier layer 20 and the heating conductor 22 fastened thereto. The position indicator 24 is aligned with the leading edge 44 of the wind turbine rotor blade 36.

[0047] It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

LIST OF REFERENCE NUMERALS

[0048] 10 heating element [0049] 12 width [0050] 14 length [0051] 16 electrical connector [0052] 18 edge [0053] 20 carrier layer [0054] 22 heating conductor [0055] 24 position indicator [0056] 26 edge [0057] 28 stitch [0058] 30 stitched yarn line [0059] 32 glass fibers [0060] 34 mesh size [0061] 36 wind turbine rotor blade [0062] 38 blade root [0063] 40 blade tip [0064] 42 trailing edge [0065] 44 leading edge [0066] 46 heating system [0067] 48 supply line [0068] 50 half shell [0069] 52 half shell