Wind turbine blade and a pitch controlled wind turbine

• US 8,678,746 B2
• Filed: 04/03/2012
• Issued: 03/25/2014
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: Vestas Wind Systems A/S
• Original Assignee: Vestas Wind Systems A/S
• Inventors: Haag, Michael Drachmann
• Primary Examiner(s): Look, Edward
• Assistant Examiner(s): EASTMAN, AARON ROBERT
• Application Number:
  US13/438,319
• Publication Number:
  US 20120189444A1
• Time in Patent Office: 721 Days
• Field of Search: 415/4.3, 415/908, 416/224, 416/236.R, 416/241.R, 416/241.A
• US Class Current: 415/4.3
• CPC Class Codes: F03D 1/0633 of the blades
• CPC Class Codes: F03D 1/0675 of the blades
• CPC Class Codes: F03D 7/0224 Adjusting blade pitch
• CPC Class Codes: F05B 2240/21 for wind turbines
• CPC Class Codes: F05B 2240/3062 Vortex generators
• CPC Class Codes: F05B 2240/32 with roughened surface
• CPC Class Codes: F05B 2250/61 corrugated
• CPC Class Codes: F05B 2260/96 Preventing, counteracting or reducing vibration or noise
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y10S 415/914 Device to control boundary layer

Abstract

The invention relates to a wind turbine blade comprising one or more turbulence generating strips, where the strips are placed on a surface of the blade. The blade is characterized in that at least one joint area of the turbulence generating strips and the surface of the blade are completely or partially covered by sealing means. The invention further relates to a pitch controlled wind turbine comprising at least two pitch controlled wind turbine blades and pitch controlling means for pitching the blades. The pitch controlled wind turbine is characterized in that the blades comprises one or more turbulence generating strips, wherein at least one joint area of the turbulence generating strips and a surface of the blades are completely or partially covered by sealing means.

Claims

1. A wind turbine blade comprising:

one or more turbulence generating strips, said strips each including a base being placed on a surface of said blade and attached to said surface by adhesive and one or more turbulence generators extending from the base,

wherein at least one joint area of said turbulence generating strips and said surface of said blade is completely covered by a sealant, such that the sealant completely isolates the adhesive from environmental conditions including moisture and UV radiation,

wherein the sealant includes a first portion overlying the surface of the wind turbine blade and a second portion overlying an edge of the base, the sealant having a maximum thickness at the at least one joint area and decreasing in thickness along the first and second portions of the sealant so that there is a smooth transition between the surface of the wind turbine blade and the base, and

wherein the edge of the base defines a rounded portion adjacent to a maximum height of the base, and wherein the sealant covers only a portion of the rounded portion such that the sealant remains spaced from the maximum height of the base.

2. A wind turbine blade according to claim 1, wherein a height of said base is reduced along at least a part of an edge of said base such that the edge is rounded or chamfered.

3. A pitch controlled wind turbine comprising:

at least two pitch controlled wind turbine blades and

a pitch controlling mechanism for pitching said blades wherein said blades comprise one or more turbulence generating strips, each of the one or more turbulence generating strips including a base attached to a surface of the wind turbine blade and one or more turbulence generators extending from the base, the base further including an edge defining a periphery of the base and a joint area at which the periphery of the base meets the surface of the wind turbine blade,

wherein at least one joint area of said turbulence generating strips and said surface of said blades is completely or partially covered by a sealant, and

wherein the edge of the base is rounded at a rounded portion such that a maximum height of the base is spaced from the joint area, and the sealant covers only a portion of the rounded portion such that the sealant remains spaced from the maximum height of the base.

4. A pitch controlled wind turbine according to claim 3, wherein said one or more turbulence generating strips are placed on an outer section of said wind turbine blades in direction of the blade tip, said outer section ranging from 60% to 100% of the length of said blade.

5. A pitch controlled wind turbine according to claim 3, wherein said wind turbine is a variable speed pitch controlled wind turbine.

6. A wind turbine blade comprising:

one or more turbulence generating strips, each of the one or more turbulence generating strips including a base attached to a surface of the wind turbine blade and one or more turbulence generators extending from the base, the base further including an edge defining a periphery of the base and a joint area at which the periphery of the base meets the surface of the wind turbine blade,

wherein at least a portion of the joint area is covered by a sealant, and

wherein the edge of the base is rounded at a rounded portion such that a maximum height of the base is spaced from the joint area, and the sealant covers only a portion of the rounded portion such that the sealant remains spaced from the maximum height of the base.

7. A wind turbine blade according to claim 6, wherein said one or more turbulence generating strips are placed on an outer section of said wind turbine blade in direction of the blade tip.

8. A wind turbine blade according to claim 7, wherein said outer section ranges from 60% to 100% of the length of said blade.

9. A wind turbine blade according to claim 7, wherein said outer section is subdivided into two or more subsections, and said turbulence generating strips are substantially uniform within each of said subsections.

10. A wind turbine blade according to claim 6, wherein said base has a longitudinal extent of between 10 and 4000 mm.

11. A wind turbine blade according to claim 10, wherein said base has a longitudinal extent of between 50 and 1000 mm.

12. A wind turbine blade according to claim 11, wherein said base has a longitudinal extent of between 100 and 500 mm.

13. A wind turbine blade according to claim 6, wherein ends of said one or more turbulence generating strips comprise one or more rounded areas as seen in a top view.

14. A wind turbine blade according to claim 6, wherein said turbulence generating strips are placed in a range between 5% and 85% of a chord length, from a leading edge of said wind turbine blade.

15. A wind turbine blade according to claim 14, wherein said turbulence generating strips are placed in a range between 10% and 75% of the chord length, from the leading edge of said wind turbine blade.

16. A wind turbine blade according to claim 15, wherein said turbulence generating strips are placed in a range between 15% and 60% of the chord length, from the leading edge of said wind turbine blade.

17. A wind turbine blade according to claim 6, wherein said wind turbine blade is a pitch controlled wind turbine blade comprising at least one pitch controlling unit.

18. A wind turbine blade according to claim 6, wherein said turbulence generating strips comprise vortex generators.

19. A wind turbine blade according to claim 6, wherein said sealant comprises a two-component polyurethane sealer.

20. A wind turbine blade comprising:

one or more turbulence generating strips, each of the one or more turbulence generating strips including a base attached to a surface of the wind turbine blade and one or more turbulence generators extending from the base, the base further including an edge defining a periphery of the base and a joint area at which the periphery of the base meets the surface of the wind turbine blade,

wherein each of the one or more turbulence generating strips is attached to the surface of the wind turbine blade by a film adhesive at the base, such that no additional fixating device is used with the film adhesive,

wherein the entire periphery of the base is covered by a sealant at the joint area, such that the sealant completely isolates the adhesive from environmental conditions including moisture and UV radiation,

wherein the sealant includes a first portion overlying the surface of the wind turbine blade and a second portion overlying the edge of the base, the sealant having a maximum thickness at the joint area and decreasing in thickness along the first and second portions of the sealant so that there is a smooth transition between the surface of the wind turbine blade and the base, and

wherein the edge of the base defines a rounded portion adjacent to a maximum height of the base, and wherein the sealant covers only a portion of the rounded portion such that the sealant remains spaced from the maximum height of the base.

21. A wind turbine blade comprising:

one or more turbulence generating strips, each of the one or more turbulence generating strips including a base attached to a surface of the wind turbine blade and one or more turbulence generators extending from the base, the base further including an edge defining a periphery of the base and a joint area at which the periphery of the base meets the surface of the wind turbine blade, wherein the edge of the base is rounded or chamfered such that a maximum height of the base is spaced from the joint area,

wherein at least a portion of the joint area is covered by a sealant, the sealant including a first portion overlying the surface of the wind turbine blade and a second portion overlying the edge of the base, the sealant having a maximum thickness at the joint area and decreasing in thickness along the first and second portions of the sealant so that there is a smooth transition between the surface of the wind turbine blade and the base; and

,

wherein the edge of the base defines a rounded portion adjacent to the maximum height of the base, and wherein the sealant covers only a portion of the rounded portion such that the sealant remains spaced from the maximum height of the base.