A BULKHEAD UNIT, A WIND TURBINE BLADE COMPRISING THE BULKHEAD UNIT, A LIFTING DEVICE AND METHODS OF ASSEMBLING AND INSTALLING THE BULKEAD UNIT

Abstract

This invention relates to a bulkhead unit, a wind turbine blade comprising the bulkhead unit, a lifting device and methods of assembling and installing the bulkhead unit in the wind turbine blade. The bulkhead unit comprises a bulkhead element substantially extending in a radial direction and a frame structure attached to the bulkhead element. The frame structure provides support for the bulkhead element and additional components mounted to the frame structure. The frame structure comprises a plurality of frame elements which are interconnected to form a number of areas that are aligned with corresponding openings in the bulkhead element. The lifting device is used to lift the bulkhead unit into position and fix the bulkhead unit relative to the blade shell.

Claims

1. A bulkhead unit (19) for a wind turbine blade (5), the wind turbine blade (5) comprising a blade shell (11) defining a blade root portion (14) having an inner blade surface (37), wherein the bulkhead unit (19) comprises a bulkhead element (26) substantially extending in a radial direction, the bulkhead element (26) having a first side (41) surface and a second side (42) surface facing in opposite longitudinal directions and a first peripheral edge facing the inner blade surface (37) of the wind turbine blade (5) when installed, wherein outer dimensions of the bulkhead element (26) substantially corresponds to inner dimensions of the blade root portion (14), characterised in that the bulkhead unit (19) further comprises a frame structure (25) extending in the radial direction, the frame structure (25) is configured to be attached to at least the bulkhead element (26) and to arranged relative to said first or second side (41, 42) surface, wherein said frame structure (25) is configured to provide support for mounting of additional components.

2. A bulkhead unit according to claim 1, characterised in that the bulkhead element (26) comprises at least one peripheral flange (31) configured to be attached to the blade shell (11) of the wind turbine blade (5), wherein said at least one peripheral flange (31) projects in one longitudinal direction from the first or second side (41, 42) surface.

3. A bulkhead unit according to claim 1, characterised in that the frame structure (25) has a second peripheral edge facing the inner blade surface (37) of the wind turbine blade (59, when installed, wherein said second peripheral edge is retracted relative the first peripheral edge.

4. A bulkhead unit according to claim 1, characterised in that the frame structure (25) comprises at least one set of frame elements (47, 48) extending in at least one direction, wherein said at least one set of frame elements (47, 48) is arranged relative to at least one opening (27, 28, 29) formed in the bulkhead element (26).

5. A bulkhead unit according to claim 4, characterised in that said at least one set of frame elements (47, 48) comprises a number of first frame elements and, optionally, a number of second frame elements, wherein the first frame elements and, optionally, the second frame elements form at least one enclosed area (46) and/or at least one open-ended area.

6. A bulkhead unit according to claim 5, characterised in that said at least one enclosed area (46) or said at least one open-ended area has inner dimensions substantially equal to or greater than inner dimensions of at least one opening (27, 28, 29) formed in the bulkhead element (26).

7. A bulkhead unit according to claim 1, characterised in that the bulkhead element (26) comprises a central part (43) and a peripheral part (44), wherein said central part (43) is configured to be attached to said peripheral part (44).

8. A bulkhead unit according to claim 2, characterised in that said frame structure (25) is contacting or spaced apart from the first or second side (41, 42) surface, wherein the frame structure (25) is attached to at least the at least one peripheral flange (31) or a central part (43) of the bulkhead element (26).

9. A bulkhead unit according to claim 1, characterised in that the frame structure (25) is positioned on one side of the bulkhead element (26) and at least one of said additional components is positioned on an opposite side of the bulkhead element (26).

10. A wind turbine blade (5) extending from a blade root (7) to a tip end (8) in a longitudinal direction and further from a leading edge (9) to a trailing edge (10) in a chordwise direction, the wind turbine blade (5) comprising a blade shell (11) having an inner surface (37) and an outer surface (36) defining a pressure side and a suction side, the blade shell (11) comprises a blade root portion (14) extending from the blade root (7), wherein a bulkhead unit (19) is arranged within the blade root portion (14) and attached to the blade shell (11), characterised in that the bulkhead unit (19) is configured according to claim 1.

11. A wind turbine blade according to claim 10, characterised in that at least one heater or blower unit (20, 21) forming part of a de-icing system is arranged within the wind turbine blade (5), wherein said at least one heater or blower unit (20, 21) is mounted to the frame structure (25) of the bulkhead unit (19).

12. A wind turbine blade according to claim 11, characterised in that said at least one heater or blower unit (20, 21) and the frame structure (25) are positioned on opposite sides or on the same side of the bulkhead element (26).

13. A wind turbine blade according to claim 11, characterised in that further additional components are mounted to the frame structure (25), wherein said further additional components form part of at least one further system.

14. A method of assembling a bulkhead for a wind turbine blade, comprising the steps of: providing a bulkhead element (26) substantially extending in a radial direction, the bulkhead element (26) having a first side (41) surface and a second side (42) surface facing in opposite longitudinal directions and a first peripheral edge, wherein outer dimensions of the bulkhead element (26) substantially corresponds to inner dimensions of a blade root portion (14) of the wind turbine blade (5), further providing a supporting frame structure (25) extending in the radial direction, the supporting frame structure (25) having a third side and a fourth side facing in opposite longitudinal directions and a second peripheral edge, positioning said supporting frame structure (25) relative to the first or second side (41, 42) surface of the bulkhead element (26), attaching said supporting frame structure (25) to the bulkhead element (26) so that the bulkhead element (26) and the supporting frame structure (25) form a pre-assembled unit, optionally, mounting at least one additional component to the frame structure (25) of said pre-assembled unit.

15. A method according to claim 14, characterised in that the method further comprises at least one of the following steps: forming at least one opening (27, 28, 29) in the bulkhead element (26) prior to positioning the supporting frame structure (25), wherein said positioning of the supporting frame structure (25) further comprises aligning the supporting frame structure (25) relative to said at least one opening (27, 28, 29), forming at least one opening (27, 28, 29) in the bulkhead element (26) after said attaching of the supporting frame structure (25).

16. A method of installing a bulkhead in a wind turbine blade, the wind turbine blade (5) extending from a blade root (7) to a tip end (8) in a longitudinal direction and further from a leading edge (9) to a trailing edge (10) in a chordwise direction, the wind turbine blade (5) comprising a blade shell (11) having an inner surface (37) and an outer surface (36) defining a pressure side and a suction side, the blade shell (11) comprises a blade root portion (14) extending from the blade root (7), characterised in that the method comprises the steps of: providing a bulkhead unit (19) according to claim 1, wherein the bulkhead unit (19) is pre-assembled prior to installation, positioning said bulkhead unit (19) within the blade root section (14), attaching the bulkhead unit (19) to the blade shell (11) so that said bulkhead unit (19) substantially seals off the blade root (7).

17. A method according to claim 16, characterised in that the method further comprises mounting a lifting device (59) to said bulkhead unit (19) via first mounting means (60) and coupling said lifting device (59) to a lifting unit, wherein the bulkhead unit (19) is lifted into an installation position relative to the blade root (7) using said lifting unit.

18. A method according to claim 17, characterised in that the lifting device (59) further comprises second mounting means (61), wherein the bulkhead unit (19) is fixed in said installation position by connecting said second mounting means (61) to the wind turbine blade (5).

19. A lifting device for installing a bulkhead unit according to claim 1, wherein the lifting device (59) comprises a body with first mounting means (60) configured to be mounted to the frame structure (25) of said bulkhead unit (19) and at least one lifting element defining at least one lifting point for coupling to an external lifting unit, characterised in that said body further comprises second mounting means (61) configured to be connected to the wind turbine blade (5) for fixing the bulkhead unit (19) in an installation position within the blade root portion (14) of the wind turbine blade (5).

20. A lifting device according to claim 19, characterised in that said body comprises one leg and at least another leg, wherein said first mounting means (60) are arranged on said one leg and said second mounting means (61) are arranged on said another leg.

21. A lifting device according to claim 19, wherein said at least one lifting element is configured to be adjustable so that the at least one lifting point can be adjusted.

Description

DESCRIPTION OF DRAWINGS

[0127] The invention is explained in detail below with reference to embodiments shown in the drawings, in which

[0128] FIG. 1 shows a wind turbine,

[0129] FIG. 2 shows an exemplary embodiment of the wind turbine blade,

[0130] FIG. 3 shows the wind turbine blade with a bulkhead unit connected to a deicing system,

[0131] FIG. 4 shows an exploded view of a first embodiment of the bulkhead unit,

[0132] FIG. 5 shows a cross-sectional view of the bulkhead unit of FIG. 4,

[0133] FIG. 6 shows the bulkhead unit of FIG. 4 seem from the trailing edge,

[0134] FIG. 7a-c show three alternative embodiments of the bulkhead element,

[0135] FIG. 8 shows a second embodiment of the frame structure,

[0136] FIG. 9 shows the bulkhead element with a third embodiment of the frame structure,

[0137] FIG. 10a-b show the bulkhead element with a fourth embodiment of the frame structure,

[0138] FIG. 11a-b shows a fifth embodiment of the bulkhead element and of the frame structure,

[0139] FIG. 12 shows an exemplary embodiment of the frame structure with projecting support elements,

[0140] FIG. 13 shows an exemplary embodiment of a lifting device, and

[0141] FIG. 14 shows the bulkhead unit with the lifting device of FIG. 13 positioned in the installation position.

LIST OF REFERENCES

[0142] 1. Wind turbine [0143] 2. Wind turbine tower [0144] 3. Nacelle [0145] 4. Hub [0146] 5. Wind turbine blades [0147] 6. Pitch bearing [0148] 7. Blade root [0149] 8. Tip end [0150] 9. Leading edge [0151] 10. Trailing edge [0152] 11. Blade shell [0153] 12. Pressure side [0154] 13. Suction side [0155] 14. Blade root portion [0156] 15. Aerodynamic blade portion [0157] 16. Transition portion [0158] 17. Length of wind turbine blade [0159] 18. Chord length of wind turbine blade [0160] 19. Bulkhead unit [0161] 20. Heater unit [0162] 21. Blower unit [0163] 22. Air guidance system [0164] 22a-b. Tubes [0165] 23. Coupling elements [0166] 24a-b. Shear webs [0167] 25. Frame structure [0168] 26. Bulkhead element [0169] 27. Access opening [0170] 28. Inlet opening [0171] 29. Outlet opening [0172] 30. Mounting plate [0173] 31. Peripheral flange [0174] 32. Outer edge surface [0175] 33. Inner edge surface [0176] 34. Thick portions [0177] 35. Thin portions [0178] 36. Outer blade surface [0179] 37. Inner blade surface [0180] 38. First side of frame structure [0181] 39. Second side of frame structure [0182] 40. Ends of frame elements [0183] 41. First side of bulkhead element [0184] 42. Second side of bulkhead element [0185] 43. Central part [0186] 44. Peripheral part [0187] 45. Mounting flanges [0188] 46. Enclosed areas [0189] 47. Main frame elements [0190] 48. Secondary frame elements [0191] 49. Outer frame element [0192] 50. Frame structure [0193] 51. First opening [0194] 52. Second opening [0195] 53. Bulkhead unit [0196] 54. Bulkhead element [0197] 55. Frame structure [0198] 56. First flange [0199] 57. Second flange [0200] 58. Support elements [0201] 59. Lifting device 59 [0202] 60. First mounting means [0203] 61. Second mounting means [0204] 62. Lifting lug [0205] 63. Adjustable mechanism [0206] 64. Holes in blade root end [0207] 65. Fasteners

[0208] The listed reference numbers are shown in abovementioned drawings where not all reference numbers are shown on the same figure for illustrative purposes. The same part or position seen in the drawings will be numbered with the same reference number in different figures.

DETAILED DESCRIPTION OF THE DRAWINGS

[0209] FIG. 1 shows a modern wind turbine 1 comprising a wind turbine tower 2, a nacelle 3 arranged on top of the wind turbine tower 2, and a rotor defining a rotor plane. The nacelle 3 is connected to the wind turbine tower 2, e.g. via a yaw bearing unit. The rotor comprises a hub 4 and a number of wind turbine blades 5. Here three wind turbine blades are shown, but the rotor may comprise more or fewer wind turbine blades 5. The hub 4 is connected to a drive train, e.g. a generator, located in the wind turbine 1 via a rotation shaft.

[0210] The hub 4 comprises a mounting interface for each wind turbine blade 5. A pitch bearing unit 6 is optionally connected to this mounting interface and further to a blade root of the wind turbine blade 5.

[0211] FIG. 2 shows a schematic view of the wind turbine blade 5 which extends in a longitudinal direction from a blade root 7 to a tip end 8. The wind turbine blade 5 further extends in a chordwise direction from a leading edge 9 to a trailing edge 10. The wind turbine blade 5 comprises a blade shell 11 having two opposite facing side surfaces defining a pressure side 12 and a suction side 13 respectively. The blade shell 11 further defines a blade root portion 14, an aerodynamic blade portion 15, and a transition portion 16 between the blade root portion 14 and the aerodynamic blade portion 15.

[0212] The blade root portion 14 has a substantially circular or elliptical cross-section (indicated by dashed lines). The blade root portion 14 together with a load carrying structure, e.g. a main laminate combined with a shear web or a box beam, are configured to add structural strength to the wind turbine blade 5 and transfer the dynamic loads to the hub 4. The load carrying structure extends between the pressure side 12 and the suction side 13 and further in the longitudinal direction.

[0213] The aerodynamic blade portion 15 has an aerodynamically shaped cross-section (indicated by dashed lines) designed to generate lift. The cross-sectional profile of the blade shell 11 gradually transforms from the circular or elliptical profile into the aerodynamic profile in the transition portion 16.

[0214] The wind turbine blade 5 has a longitudinal length 17 of at least 35 metres, preferably at least 50 metres. The wind turbine blade 5 further has a chord length 18 as function of the length 17, wherein the maximum chord length is found between the blade aerodynamic blade portion 15 and the transition portion 16. The wind turbine blade 5 further has a blade thickness 19 as function of the chord length 18, wherein the blade thickness 19 is measured between the pressure side 12 and the suction side 13.

[0215] FIG. 3 shows the wind turbine blade 5 with a bulkhead unit 19 connected to a de-icing system. The bulkhead unit 19 is arranged in the blade root portion 14 at a predetermined distance from the blade root 7. The bulkhead unit 19 comprises a bulkhead element (shown in FIG. 4) and a frame structure (shown in FIG. 4).

[0216] The de-icing system comprises a heater unit 20 in fluid communication with a separate blower unit 21. The heater unit 20 is configured to heat up the incoming air being guided into an air guidance system 22 via the blower unit 21. The blower unit 21 is configured to suck the returning air out of the air guidance system 22 and into the heater unit 20. The heating unit 20 and the blower unit 21 are each mounted to the frame structure which provides support for these units.

[0217] The heater and blower units 20, 21 are further in fluid communication with the air guidance system 22 via suitable inlet and outlet elements 23. The inlet and outlet elements 23 are here formed as flexible tube sections. The air guidance system 22 here comprises a first fluid path formed by one set of tubes 22a and a second fluid path formed by another set of tubes 22b. The sets of tubes 22a, 22b are in fluid communication with each other for circulating air inside the wind turbine blade 5.

[0218] The air guidance system 22 is attached to the load carrying structure of the wind turbine blade 5. Here, the load carrying structure comprises two shear webs 24a, 24b extending in the longitudinal direction. The blade shell 11 has an inner blade surface and an outer blade surface as indicated in FIG. 5, wherein the shear webs 24 project inwards from the opposite facing inner surfaces.

[0219] FIG. 4 shows an exploded view of a first embodiment of the bulkhead unit 19. As indicated, the bulkhead element 26 comprises a plurality of openings arranged in the side surface adapted for a particular purpose. The bulkhead element 26 is here arranged with an access opening 27, an inlet opening 28, an outlet opening 29. The bulkhead element 26 further comprises an opening for guiding electrical cables, data cables or optical fibre cables through the bulkhead unit 19.

[0220] Here, the heater and blower units 20, 21 are formed as an integrated unit extending through the inlet and outlet openings 28, 29 as illustrated in FIG. 5. The heater and blower units 20, 21 are arranged on the opposite side of the bulkhead element 26 in relation to the frame structure 25. A separate mounting plate 30 is used to mount this integrated unit to the frame structure 25.

[0221] The bulkhead element 26 here has a U-shaped profile comprising a peripheral flange 31 projecting from a central part of the bulkhead element 26. The peripheral flange 31 defining a first peripheral edge with an outer edge surface 32 and an inner edge surface 33.

[0222] The frame elements of the frame structure 25 divides the surface areas of the bulkhead element 26 into a plurality of open-ended areas, as illustrated in FIG. 4.

[0223] FIG. 5 shows a cross-sectional view of the bulkhead unit 19 with the frame structure 25 omitted for illustrative purposes. The central part of the bulkhead element 26 has a plurality of thick portions 34 and a plurality of thin portions 35 arranged relative to each other. The thin portions 35 defines contact areas dedicated for mounting of the frame structure 25 as indicated in FIG. 4.

[0224] The bulkhead unit 19 is arranged within the blade root portion of the wind turbine blade 5. Here, the bulkhead unit 19 is placed at a distance from the blade root 7. The heater and blower units 20, 21 are omitted for illustrative purposes.

[0225] The blade shell 11 has an outer blade surface 36 and an inner blade surface 37. The bulkhead element 26 is bonded to the blade shell 11 via an adhesive layer (not shown) arranged between the outer edge surface 32 and the inner blade surface 37.

[0226] The frame structure 25 has a first side 38 facing the blade root 7 and a second side 39 facing the tip end 8. The frame structure 25 has a second peripheral edge comprising an end 40 having a tapered profile. The end 40 tapers from the first side 38 to the second side 39.

[0227] As indicated in FIG. 6, the second peripheral edge is retracted relative to the first peripheral edge. This means that the frame structure 25 has an outer diameter that is smaller than the outer diameter of the bulkhead element 26.

[0228] FIG. 7a-c show three alternate embodiments of the bulkhead element 26, where the bulkhead element 26, 26, 26 has a first side 41 and a second side 42.

[0229] In FIG. 7a, the bulkhead element 26 has a continuous U-shaped profile defining an integrated central part 43 from which the peripheral flange 31 projects in the longitudinal direction. In FIG. 7b, the bulkhead element 26 has a peripheral part 44 and a separate central part 43 configured to be attached to the peripheral part 44. In FIG. 7c, the bulkhead element 26 has a plate-shaped profile which is connected to a number of mounting means, e.g. mounting bracket 45. The mounting brackets 45 may be made of a flexible material or have a flexible structure to allow deformation.

[0230] FIG. 8 shows a second embodiment of the frame structure 25 seem from the second side 39. The frame structure 25 comprises a number of individual frame elements interconnected to form a plurality of enclosed areas 46. The inner dimensions of the areas 46 are adapted to the inner dimensions of the openings 27, 28, 29 in the bulkhead element 26.

[0231] The frame structure 25 comprises two sets of main frame elements 47 extending in different directions. The individual main frame elements 47 are interconnected via two sets of secondary frame elements 48. The individual main frame elements 47 are further connected to an outer frame element 49 extending along the circumference.

[0232] FIG. 9 shows another embodiment of the bulkhead unit 19 with a third embodiment of the frame structure 50 attached to the bulkhead element 26. The additional components are here omitted for illustrative purposes.

[0233] The frame structure 50 comprises a funnel-shaped frame element having a first opening 51 and a second opening 52. The first opening 51 is facing a corresponding opening in the bulkhead element 26. The second opening 52 is facing away from the bulkhead element 26. The sides of the frame elements project outsides from the second side 42 or, alternatively, the first side 41 of the bulkhead element 26.

[0234] The frame element comprises flanges arranged at the first opening 51 for attachment to the bulkhead element 26, e.g. using adhesive or bolts. An additional component, e.g. the heater and blower unit 20, 21, is arranged relative to and attached to the frame element, e.g. extending through the first opening 51 and/or the second opening 52.

[0235] FIG. 10a-b show another configuration of the bulkhead unit 19 where a fourth embodiment of the frame structure 25 is attached to the bulkhead element 26. Here, the additional components have been omitted from FIG. 10b for illustrative purposes.

[0236] The frame structure 25 is spaced apart from the first side 41 of the central part of the bulkhead element 26, as illustrated in FIG. 10a. The frame structure 25 is in this configuration attached to the peripheral flange 31 of the bulkhead element 26. The heater and blower units 20, 21 are thereby positioned at a distance from the central part, allowing cables, tubes and the like to be routed between the frame structure 25 and the central part.

[0237] In this configuration, the sizes of the respective openings 28, 29 have a reduced size (indicated by dashed lines) in relation to the same openings 28, 29 illustrated in FIG. 4. Thereby, the respective openings 28, 29 have a size smaller than the size of the enclosed areas formed by the frame structure 25, as illustrated in FIG. 10b. The opening 29 in the configuration shown in FIG. 4 may have a size substantially equal to the size of the enclosed areas formed by the frame structure 25, as illustrated in FIG. 10b.

[0238] FIG. 11a-b show an alternative embodiment of the bulkhead unit 53 with a fifth embodiment of the bulkhead element 54 and of the frame structure 55. Here, the additional components have been omitted from FIG. 11b for illustrative purposes.

[0239] The central part of the bulkhead element 54 is in this embodiment formed by the frame structure 55, as illustrated in FIG. 11a. The bulkhead element 54 is formed as a peripheral part comprising the peripheral flange 31 and a first flange 56 facing in the radial direction. The first flange 56 is configured to be attached a second flange 57 on the frame structure 55.

[0240] The frame structure 55 has an overall disc-shaped profile, wherein a plurality of individual sub-elements are joined together to form the disc-shaped frame element, as illustrated in FIG. 11b.

[0241] FIG. 12 shows an exemplary embodiment of the frame structure 50 with a plurality of support elements 58 projecting from the second side 42. The support elements 58 are here shaped as ribs extending in the length direction of the individual sub-elements, as illustrated in FIG. 11b.

[0242] The support elements 58 are integrated into the frame structure 55, e.g. into each sub-element. The support elements 58 are spaced apart evenly over the second side 42.

[0243] FIG. 13 shows an exemplary embodiment of a lifting device 59 for use during installation of the bulkhead unit 19, 53. The lifting device 59 comprises a U-shaped body with first mounting means 60 in form of a mounting bracket configured to be mounted to the frame structure 25, 25, 25, 50, 55.

[0244] The lifting device 59 further comprises second mounting means 61 in the form of another mounting bracket configured to be mounted to the blade root 7 end of the wind turbine blade, as illustrated in FIG. 14.

[0245] The lifting device 59 comprises an adjustable lifting lug structure defining a lifting point for coupling to a lifting unit. The lifting lug 62 is connected to an adjustable mechanism 63 attached to the body, allowing the lifting point to be adjusted.

[0246] FIG. 14 shows the bulkhead unit 15, 53 with the lifting device 59 positioned in the installation position. Here, the lifting unit and the additional components are omitted for illustrative purposes. Further, parts of the blade shell 11 are omitted for illustrative purposes.

[0247] Prior to lifting the bulkhead unit 19, the lifting device 59 is positioned relative to the frame structure 25, 25, 25 and the first mounting means 60 is fastened to the frame structure 25, 25, 25. The lifting unit is then coupled to the lifting lug 62.

[0248] The pre-assembled bulkhead unit 19 is lifting into alignment relative to the orientation of the blade root 7. Optionally, the bulkhead unit 19 is rotated during the lifting process so that it is aligned with the blade root 7. The bulkhead unit 19 is further lifted into the blade root portion 14 and placed into the installation position, as illustrated in FIG. 14.

[0249] Holes (shown in FIG. 13) on the second mounting means 61 are afterwards aligned with corresponding holes 64 in the blade root 7 end. Fasteners 65 in the form of bolts are inserted into the aligned holes for mounting the lifting device 59 to the blade root 7, thereby fixing the bulkhead unit 19 relative to the blade shell 11.

[0250] The bulkhead unit 19 is afterwards attached to the blade shell 11. Once the attachment process is completed, the fasteners 65 are removed and the first mounting means 60 is demounted. The lifting device 59 is then removed from the wind turbine blade 5.

[0251] The abovementioned embodiments may be combined in any combinations without deviating from the present invention.