Wind turbine rotor blade, wind turbine and method for operating a wind turbine

Patent metadata

Field	Value
Publication number	US-10465656-B2
Application number	US-201515318960-A
Country	US
Kind code	B2
Filing date	Jun 17, 2015
Priority date	Jun 18, 2014
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A rotor blade of a wind turbine, comprising a first rotor-blade portion and a second rotor-blade portion. In this case, the first and the second rotor-blade portion constitute a total length of the rotor blade and, upon a rotation of the rotor blade, the first rotor-blade portion and the second rotor-blade portion can be moved relative to each other, along a longitudinal axis of the rotor blade, as a result of a centrifugal force acting upon the rotor blade, in such a way that the total length of the rotor blade can be altered.

First claim

The invention claimed is:

1. A wind-turbine rotor blade, comprising:
a first rotor-blade portion; and
a second rotor-blade portion,
the first and the second rotor-blade portions together forming a total length of the rotor blade, and the first and second rotor-blade portions configured so that in response to a rotation of the rotor blade, at least one of the first rotor-blade portion and the second rotor-blade portion move relative to each other as a result of a centrifugal force acting upon the rotor blade in such a way that the total length of the rotor blade is altered to an altered total length, wherein the movement is along a longitudinal axis of the rotor blade,
wherein at least a portion of the second rotor-blade portion is disposed in the first rotor-blade portion, wherein the first rotor-blade portion has an opening, a portion of the second rotor-blade portion being configured to move in and out of the opening of the first rotor-blade portion, and
wherein the first rotor-blade portion has a guide device for guiding and supporting the second rotor-blade portion inside the opening of the first rotor-blade portion, the guide device having at least two guide elements for guiding the second rotor-blade portion in the direction of the longitudinal axis of the rotor blade, and at least two spring elements coupling the at least two guide elements to the first rotor-blade portion.

2. The rotor blade according to claim 1 , wherein the second rotor-blade portion is connected to the first rotor-blade portion by a rope winch device for retracting the second rotor-blade portion into the first rotor-blade portion.

3. The rotor blade according to claim 2 , wherein the rope winch device comprises a rope for fastening to the second rotor-blade portion, the rope being made of a synthetic, polyethylene-based chemical fiber.

4. The rotor blade according to claim 2 , wherein the rotor blade has a measuring means for measuring wind speed, and the rope winch device is configured so that the second rotor-blade portion retracts and extends at predefined windspeeds, respectively.

5. The rotor blade according to claim 1 , wherein the guide elements are rollers.

6. The rotor blade according to claim 1 , wherein the guide device is box shaped and is disposed inside the first rotor-blade portion.

7. The rotor blade according to claim 1 , wherein the guide device has a length that is one third of a length of the second rotor-blade portion that moves out of the first rotor-blade portion.

8. The rotor blade according to claim 1 , wherein a length of the portion of the second rotor-blade portion that moves out of the opening of the first rotor-blade portion corresponds approximately to one tenth of the total length of the rotor blade.

9. The rotor blade according to claim 1 , wherein the first rotor-blade portion has a first rotor-blade tip, and the second rotor-blade portion has a second rotor-blade tip, the first rotor-blade tip and the second rotor-blade tip each being realized as winglets, and the second rotor-blade tip being provided in an opposite direction to the first rotor-blade tip.

10. The rotor blade according to claim 9 , wherein the second rotor-blade portion has a stop at an end opposite to the second rotor-blade tip in a longitudinal direction, wherein the stop ensures a predefined extendable length.

11. The rotor blade according to claim 1 , wherein the second rotor-blade portion has a substantially constant profile depth over its entire length.

12. The rotor blade according to claim 9 , wherein at least one of the first and second rotor-blade portions is produced substantially from a fibrous composite material or wood, and at least one of the first and second rotor-blade tips is produced from a conductive material.

13. The rotor blade according to claim 1 , wherein at least one of the first and the second rotor-blade portions is connected to a lightning protection means by a metal rail or a metal cable.

14. A wind turbine comprising:
a nacelle;
a rotor; and
at least one rotor blade according to claim 1 coupled to the rotor.

15. The wind turbine according to claim 14 , wherein a diameter of the rotor is enlarged in response to a rotation of the rotor blade.

16. A method for operating a wind turbine having at least one wind-turbine rotor blade according to claim 1 , the method comprising:
rotating the at least one wind-turbine rotor blade, wherein rotating the at least one wind-turbine rotor blade causes the second rotor-blade portion to move relative to the first rotor-blade portion as a result of an occurring centrifugal force.

17. The method according to claim 16 , wherein the second rotor-blade portion is moved out of the first rotor-blade portion as a result of the centrifugal force occurring such that a surface area of the at least one wind-turbine rotor blade acted upon by the wind is enlarged.

18. The method according to claim 16 , further comprising moving the second rotor-blade portion back into the first rotor-blade portion using a rope winch device such that a first surface area of the rotor blade acted upon by wind is reduced in comparison with a second surface area acted upon by the wind in the case of a fully extended second rotor-blade portion.

19. The method according to claim 16 , wherein the method occurs in light wind.

20. The rotor blade according to claim 1 , wherein the guide device has four guide elements and four spring elements.

21. The rotor blade according to claim 20 , wherein guide device includes a box, wherein the four guide elements are four rollers, wherein the four rollers and the four spring elements are distributed over an entire length of the box.

Assignees

• Wobben Properties Gmbh

Inventors

• Hoffmann Alexander

Classifications

• F03D80/30

  Lightning protection · CPC title

• F03D1/0633

  of the blades · CPC title

• F03D1/0675 Primary

  of the blades · CPC title

• F05B2240/312

  capable of being reefed · CPC title

• F03D7/0236 Primary

  by changing the active surface of the wind engaging parts, e.g. reefing or furling · CPC title