DAMPER FOR A WIND TURBINE

Abstract

A damper for damping movements of a wind turbine, in particular for damping oscillatory movements of a tower of the wind turbine is provided. The damping of the movements is achieved by an aqueous liquid contained in a container of the damper. The aqueous liquid includes water and the components included in the aqueous liquid are completely dissolved. The composition includes a citrate, e. g. potassium citrate and/or sodium citrate. A wind turbine including the damper is also provided. Finally, a specific composition is provided. The composition is destined to be dissolved, e. g. in water, to result in the aqueous liquid.

Claims

1. A damper for damping movements of a wind turbine, in particular for damping oscillatory movements of a tower of the wind turbine, wherein the damping of the movements is achieved by an aqueous liquid contained in a container of the damper, wherein the aqueous liquid comprises at least one citrate.

2. The damper according to claim 1, wherein the citrate is selected from potassium citrate and/or sodium citrate.

3. The damper according to claim 1, wherein the amount of citrate in the aqueous liquid is at least 30% by weight and/or less than 70% by weight.

4. The damper according to claim 1, wherein the amount of citrate in the aqueous liquid is at least 50% by weight and/or less than 65% by weight.

5. The damper according to claim 1, wherein the aqueous liquid comprises water.

6. The damper according to claim 1, wherein the aqueous liquid further comprises an antifreeze.

7. The damper according to claim 6, wherein the antifreeze comprises monoethylene glycol and/or monopropylene glycol.

8. The damper according to claim 1, wherein the aqueous liquid further comprises a corrosion inhibitor for reducing or even preventing corrosion of parts of the damper.

9. The damper according to claim 8, wherein the corrosion inhibitor is selected from at least one of a carbonate, borate, molybdate, nitrate, silicate, amine, sulfonate and/or azole.

10. The damper according to claim 1, wherein the aqueous liquid further comprises a biocide, such as an antimicrobial or a pesticide.

11. The damper according to claim 1, wherein the aqueous liquid comprises: water, at an amount of at least 25% by weight and/or up to 45% by weight, at least one citrate, at a total amount of at least 50% by weight and/or up to 63% by weight, monopropylene glycol at an amount of at least 5% by weight and/or up to 15% by weight and at least one corrosion inhibitor at a total amount of at least 2% by weight and/or up to 5% by weight.

12. A wind turbine comprising the damper according to claim 1.

13. The wind turbine according to claim 12, wherein the damper is located in the upper third of a tower of the wind turbine.

14. A composition comprising (a) potassium citrate at an amount of at least 40% by weight and/or up to 65% by weight, or 50% by weight, (b) optionally sodium citrate at an amount of 0.1% by weight and/or up to 20% by weight, or 10% by weight, (c) monopropylene glycol at an amount of 20% by weight and/or up to 40% by weight, or 30% by weight, (d) optionally monoethylene glycol at an amount of up to 30% by weight, and (e) at least one corrosion inhibitor at a total amount of at least 1% by weight and/or up to 5% by weight, wherein components (a) to (e) are dispersed in a liquid.

15. The composition according to claim 14 for use in a damper.

16. An aqueous liquid comprising water, at an amount of at least 10% by weight and/or up to 50% by weight, potassium citrate at an amount of at least 1% by weight and/or up to 60% by weight, or at an amount of at least 25% and/or up to 60% by weight, and optionally sodium citrate at an amount of at least 1% by weight and/or up to 60% by weight, monoethylene glycol at an amount of at least 1% by weight and/or up to 30% by weight and/or monopropylene glycol at an amount of at least 1% by weight and/or up to 30% by weight, and optionally at least one corrosion inhibitor at a total amount of at least 1% by weight and/or up to 5% by weight.

17. The aqueous liquid according to claim 16 for use in a damper.

Description

BRIEF DESCRIPTION

[0117] Some of the embodiments will be described in detail, with reference to the following FIGURES, wherein like designations denote like members, wherein:

[0118] FIG. 1 shows a wind turbine with a tower damper.

DETAILED DESCRIPTION

[0119] FIG. 1 shows a wind turbine 10 comprising a tower 11 with a base 113 and a top 114. At the top 114 of the tower 11 a nacelle 12 is placed. The nacelle 12 accommodates a generator (not shown) and a rotor (not shown) of the wind turbine 10. At one side of the nacelle 12, a hub 14 is mounted. The hub 14 is mounted rotatable with regard to the nacelle 12. The hub 14 is provided with three rotor blades 15, of which two are shown in FIG. 1. The wind turbine 10 might be a direct drive wind turbine without a gear box or a geared wind turbine with a gear box.

[0120] The height of the tower 11 exemplarily exceeds seventy meters. Thus, it is convenient to provide an elevator 13 which connects the base 113 of the tower 10 with the top 114 of the tower 10. The elevator 13 is basically used for the service personnel which needs to access the nacelle 12, the hub 14 or the rotor blades 15. Alternatively, stairs or a ladder may also be installed inside of the tower 11. The space which is needed and occupied by the elevator 13 is referred to as space 16 for the elevator 13. Close to the top 114 of the tower 11 a damper 20 with a shape of a toroid is located. Various other shapes of the damper, e.g., cuboid or cylindrical shapes, are possible, too. The damper 20 comprises a container 40 which is filled with an aqueous liquid 30 according to embodiments of the present invention. The damper 20 is placed close to the space 16 for the elevator 13.

[0121] An aspect of the damper 20 is to damp, i.e., to reduce movements of the tower 11. These movements may be linear movements in a plane perpendicular to the tower 11 or circular or elliptical movements. The movements may be oscillating movements. Due to the mass of the aqueous liquid 30, a force which is acting against the movement of the tower 11 is damping this movement. The damper 20 comprises an aqueous liquid 30 as described in the description of embodiments of the invention above.

[0122] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0123] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements.