Wind Turbine Blades Made of Two Separate Sections, and Method of Assembly

• US 20080069699A1
• Filed: 06/30/2004
• Published: 03/20/2008
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Vestas Wind Systems A/S
• Original Assignee: Vestas Wind Systems A/S
• Inventors: Bech, Anton
• Granted Patent: US 8,348,622 B2
• Time in Patent Office: Days
• US Class Current: 416/229R
• CPC Class Codes: B29C 65/00 Joining or sealing of preformed parts , e.g. welding of plastics materials; Apparatus therefor general aspects of processes or apparatus for joining preformed parts B29C66/00; using porous material formed by internal pressure generated therein for joining preformed parts B29C44/1228, B29C44/326
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 66/1142 Single butt to butt joints
• CPC Class Codes: B29C 66/1162 Single bevel to bevel joints, e.g. mitre joints
• CPC Class Codes: B29C 66/20 particular design of the joint lines, e.g. of the weld lines
• CPC Class Codes: B29C 66/223 being in the form of a triangle wave or of a sawtooth wave, e.g. zigzagged
• CPC Class Codes: B29C 66/54 Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/721 Fibre-reinforced materials B29C66/729 takes precedence
• CPC Class Codes: B29C 66/7212 characterised by the composition of the fibres
• CPC Class Codes: B29C 66/72141 Fibres of continuous length
• CPC Class Codes: B29C 66/7254 honeycomb structures
• CPC Class Codes: B29C 66/9121 by measuring the temperature
• CPC Class Codes: B29C 66/9141 by controlling or regulating the temperature
• CPC Class Codes: B29C 66/9161 by controlling or regulating the heat or the thermal flux, i.e. the heat flux
• CPC Class Codes: B29C 66/9534 of the atmosphere, i.e. taking the ambient humidity into account
• CPC Class Codes: B29C 66/961 involving a feedback loop mechanism, e.g. comparison with a desired value
• CPC Class Codes: B29C 70/304 In-plane lamination by juxtaposing or interleaving of plies, e.g. scarf joining
• CPC Class Codes: B29K 2063/00 Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/101 : Oriented
• CPC Class Codes: B29K 2307/00 : Use of elements other than metals as reinforcement
• CPC Class Codes: B29K 2307/04 : Carbon
• CPC Class Codes: B29K 2309/08 : Glass
• CPC Class Codes: B29L 2031/08 : Blades for rotors, stators, fans, turbines or the like, e.g. screw propellers
• CPC Class Codes: B29L 2031/085 : Wind turbine blades
• CPC Class Codes: B29L 2031/7504 : Turbines
• CPC Class Codes: F03D 1/0675 : of the blades
• CPC Class Codes: F05B 2230/23 : by permanently joining parts together
• CPC Class Codes: F05B 2240/302 : Segmented or sectional blades
• CPC Class Codes: Y02E 10/72 : Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49336 : Blade making

Abstract

The invention relates to a wind turbine blade (5) comprising at least two wind turbine blade sections (12, 13) that include one or more strengthening structures (6, 6a, 6b), the ends (14, 15) of said strengthening structures being connected in a connection joint. The ends include corresponding connection surfaces, the one or more relevant dimensions of said surfaces being larger than the dimensions of the transverse surfaces of the strengthening structures at said ends. The one or more relevant dimensions of said connection joint are larger than that of the adjacent strengthening structure. The invention also relates to a wind turbine blade in which the at least two wind turbine blade sections include a number of substantially oblong carbon fiber strips and strips of one or further materials such as wood or glass fiber. The invention further relates to a wind turbine blade section, an assembly plant for assembling wind turbine blade sections (12, 13) and to a method and use of such wind turbine blades.

Claims

1. Wind turbine blade comprising

at least two wind turbine blade sections that include one or more strengthening structures, ends of said strengthening structures being connected in a connection joint,

wherein said ends include corresponding connection surfaces, one or more relevant dimensions of said connection surfaces being larger than dimensions of transverse surfaces of the strengthening structures at said ends,

wherein one or more relevant dimensions of said connection joint is enlarged in relation to the adjacent strengthening structure, and

wherein adhering means adhere the connection surfaces to each other.

2. Wind turbine blade according to claim 1 wherein the ends of said strengthening structures of the blade sections are shaped as a number of corresponding or partly corresponding dentated ends.

3. Wind turbine blade according to claim 2 wherein teeth of said dentated ends are shaped as triangles, four-sided teeth, round shapes, free-hand shapes, or a combination of different shapes.

4. Wind turbine blade according to claim 3 wherein sides of the teeth comprise a pie shape comprising rounded or wedge shaped teeth in order to establish corners in a strengthening structure.

5. Wind turbine blade according to claim 2 wherein said dentated ends partly corresponding to each other and cavities are filled with one or more intermediate connection means.

6. Wind turbine blade according to claim 5 wherein adhering means, adheres the corresponding dentated ends and/or said one or more intermediate connection means to each other.

7. Wind turbine blade according to claim 1 wherein said one or more relevant dimensions of said connection surfaces, transverse surfaces, connection joint and adjacent strengthening structure may be area, length or thickness values.

8. Wind turbine blade according to claim 1 wherein said one or more relevant dimensions of said connection joint is larger than that of the adjacent strengthening structure in a direction of a root of the wind turbine blade.

9. Wind turbine blade according to claim 3 wherein the length l of one of said teeth in an enlarged connection joint is given by

10. Wind turbine blade according to claim 3 wherein a number of teeth in the dentated ends is between 25 and 200 per meter of strengthening structure.

11. Wind turbine blade according to claim 1 wherein said one or more strengthening structures comprise an internal beam strengthening structure, an internal strengthening structure at a trailing edge and/or an internal strengthening structure of a surface shell structure including a plurality of oblong strips imbedded in a blade surface comprising carbon, wood and/or glass fiber strips.

12. Wind turbine blade according to claim 1 wherein enlargement of said connection joint is symmetrical in relation to the adjacent strengthening structure comprising a symmetrical in- and outwardly expansion in relation to a course of the adjacent strengthening structure.

32. Assembly plant for assembling wind turbine blade sections, to a wind turbine blade according to claim 1, said plant comprising

means to position the wind turbine blade sections in relation to each other such in order to create a connection joint between the sections with adhering means adhering the connection surfaces to each other,

enclosure for at least enclosing the connection joint of the wind turbine blade sections, and

means for controlling one or more environmental values within the enclosure.

33. Assembly plant according to claim 32, wherein said means for controlling one or more environmental values include a heat supply and humidity control temperature and humidity sensors, and control means for controlling the adhesive process.

34. Assembly plant according to claim 32, wherein said means to position the wind turbine blade sections include actuators for moving at least one section in a vertical and horizontal plane in relation to another section, position measuring means such as a transmitter and receiver positioned on a wind blade section, respectively as well as transmitter and receiver means and control means.

35. Assembly plant according to an claim 32, wherein said enclosure is a tent tightly enclosing the connection joint in relation to temperature and/or humidity.

13. Wind turbine blade comprising

at least two wind turbine blade sections that include one or more strengthening structures with a number of substantially oblong carbon fiber strips and strips of one or further materials,

wherein ends of said strengthening structures being connected in a connection joint,

wherein said ends include corresponding connection surfaces, one or more relevant dimensions of said surfaces being larger than dimensions of transverse surfaces of the strengthening structures at said ends, and

wherein adhering means adhere the connection surfaces to each other.

14. Wind turbine blade according to claim 13 wherein the carbon fibers of said substantially oblong carbon fiber strips in each wind turbine blade section are unbroken.

15. Wind turbine blade according to claim 13 wherein corresponding ends of said carbon fiber strips are connected and corresponding ends of said strips of one or further materials are connected in the connection joint.

16. Wind turbine blade according to claim 13 wherein the ends of said strengthening structures of the blade sections are shaped as a number of corresponding or partly corresponding dentated ends.

17. Wind turbine blade according to claim 16 wherein teeth of said dentated ends are shaped as triangles, four-sided teeth, round shapes, free-hand shapes, or a combination of different shapes.

18. Wind turbine blade according to claim 17 wherein sides of the teeth comprise a pie shape comprising rounded or wedge shaped teethe in order to establish corners in a strengthening structure.

19. Wind turbine blade according to claim 17 wherein a length of one of said teeth in connection joint is given by

20. Wind turbine blade according to claim 17 wherein the number of teeth in the dentated ends is between 25 and 200 per meter of blade surface.

21. Wind turbine blade according to claim 16 wherein said dentated ends partly corresponding to each other and cavities are filled with one or more intermediate connection means.

22. Wind turbine blade according to claim 21 wherein adhering means, adheres the corresponding dentated ends and/or said one or more intermediate connection means to each other.

23. Wind turbine blade according to claim 13 wherein said one or more strengthening structures comprise an internal beam strengthening structure, an internal strengthening structure at a trailing edge and/or an internal strengthening structure of a surface shell structure including a plurality of oblong strips imbedded in a blade surface comprising carbon, wood and/or glass fiber strips.

24. Wind turbine blade according to claim 13 wherein said connection joint is enlarged in relation to the adjacent strengthening structure.

25. Wind turbine blade according to claim 24 wherein a length l of one of said teeth in the enlarged connection joint is given by

26. Wind turbine blade according to claim 24 wherein said one or more relevant dimensions of said connection joint is larger than that of the adjacent strengthening structure in a direction of a root of the wind turbine blade.

27. Wind turbine blade according to claim 24 wherein the enlargement of said connection joint is symmetrical in relation to the adjacent strengthening structure comprising a symmetrical in- and outwardly expansion in relation to a course of the adjacent strengthening structure.

28. Wind turbine blade according to claim 24 wherein said one or more relevant dimensions of said connection surfaces, transverse surfaces, said connection joint and adjacent strengthening structure comprises area, length or thickness values.

29. Wind turbine blade according to of claim 13 wherein the connection joint is covered with a cover surface.

30. Wind turbine blade section to be used in a wind turbine blade, said blade section comprising

a strengthening structure with an end including a connection surface for connection to another blade section,

one or more relevant dimensions of said surface being larger than dimensions of transverse surfaces of the strengthening structures at said end, and

wherein said structure end includes a connection surface applied with connection means concealed behind a removable cover.

31. Wind turbine blade section according to claim 30 wherein said connection means is adhering means, such which is concealed behind air tight plastic layers of the removable cover e.g. with use of latent cure or hot melt technology.

36. Method of assembling wind turbine blade sections to wind turbine blades in a place different from a manufacturing place of said wind turbine blade sections, said method comprising:

creating at least one connection surface in one end of a strengthening structure of each section ready for connection where one or more dimensions of said surface are larger than a transverse surface of the structure,

positioning the wind turbine blade sections in relation to each other with elevation means,

connecting the wind turbine blade sections at said at least one connection surface by using connection means with adhesive means,

where at least one environmental value of the connection area is controlled during the assembling.

37. Method according to claim 36, where the environmental values for temperature and humidity is controlled in an enclosed space.

38. Method according to claim 36, where the wind turbine blade sections are connected with adhesive means, said means being exposed by removing a removable cover before the connection.

39. Method according to claim 36, where the surfaces of said sections are bonded using adhering means comprising two-component epoxy adhesive.

40. Method according to claim 36, where a connection joint is closed with a cover surface.

41. (canceled)

42. (canceled)