Wind turbine blade comprising a bulkhead

Abstract

This invention relates to a method of manufacturing a bulkhead unit, a method of installing a bulkhead unit, a bulkhead, a bulkhead unit and a wind turbine blade. The bulkhead is manufactured by vacuum forming or rotational moulding and has a set of predetermined openings formed during manufacturing. Various additional elements are pre-mounted or pre-integrated into the bulkhead before installation of the bulkhead unit. This pre-assembled unit can then be positioned inside the blade root section and connected to the blade section.

Claims

1. A method of manufacturing a bulkhead unit (16) for a wind turbine blade (5), the wind turbine blade (5) extends in a longitudinal direction from a blade root (6) to a tip end (7) and in a chordwise direction from a leading edge (8) to a trailing edge (9), wherein the method comprises the steps of: manufacturing a bulkhead (17), wherein the bulkhead (17), when installed, extends in a radial direction and has at least a first side, a second side, and an outer circumference, the first and second sides face in opposite longitudinal directions and the outer circumference is arranged in a radial plane, wherein the bulkhead (17) comprises a first bulkhead part and at least one second bulkhead part (19, 21), wherein said at least one second bulkhead part (19, 21) is manufactured by rotational moulding or vacuum forming; aligning the at least one second bulkhead part relative to the first bulkhead part in the longitudinal or radial direction; and bringing the first bulkhead part and the at least one second bulkhead part into contact with each other to form the bulkhead (17″, 17′″), wherein the first bulkhead part is arranged relative to the at least one second bulkhead part such that a first installation flange (20a) of the first bulkhead part contacts a second installation flange (20b) of the at least one second bulkhead part.

2. The method according to claim 1, wherein the method further comprises the step of mounting or integrating at least one element (18) on the bulkhead (17) prior to installation of the bulkhead unit (16), wherein said at least one element (18) is arranged on at least one of a first side of the first bulkhead part and a second side of the at least one second bulkhead part.

3. A method of installing the bulkhead unit (16) according to claim 1 in the wind turbine blade (5) of a wind turbine (1), the wind turbine blade (5) extends in the longitudinal direction from the blade root (6) to the tip end (7) and in the chordwise direction from the leading edge (8) to the trailing edge (9), wherein the wind turbine blade (5) comprises a blade shell (10) defining a pressure side (11) and a suction side (12), the wind turbine blade (5) further comprises a blade root section (13) comprising the blade root (6), wherein the method comprises the steps of: providing at least one of the bulkhead unit (16), wherein the at least one bulkhead unit (16) is pre-assembled prior to installation; positioning said at least one bulkhead unit (16) in the blade root section (13) at a predetermined distance from the blade root (6); and installing the at least one bulkhead unit (16) inside the wind turbine blade (5) so that said at least one bulkhead unit (16) substantially seals off the blade root.

4. The method according to claim 3, wherein the method further comprises the step of milling an inner surface of the blade root section (13) prior to positioning the at least one bulkhead unit (16) in the blade root section (13).

5. The method according to claim 3, wherein the method further comprises the step of mounting or integrating at least one adjustable element (25) and/or at least one deformable element (26) at the circumference of the at least one bulkhead unit (16) prior to positioning the at least one bulkhead unit (16) in the blade root section (13).

6. A bulkhead (17), having a first side, an opposite second side and an outer circumference, wherein said bulkhead (17) comprises a first bulkhead part and at least one second bulkhead part (19, 21), wherein said at least one second bulkhead part (19, 21) is manufactured by rotational moulding or vacuum forming, and wherein the first bulkhead part is arranged relative to the at least one second bulkhead part such that a first installation flange (20a) of the first bulkhead part contacts a second installation flange (20b) of the at least one second bulkhead part.

7. A bulkhead unit (16), the bulkhead unit (16) is configured to be installed in a blade root section (13) of a wind turbine (1), wherein the bulkhead unit (16) is a pre-assembled unit comprising: the bulkhead (17) according to claim 6; and at least one element (18) mounted on or integrated into said bulkhead (17), wherein said at least one element (18) is arranged on at least one of said first and second sides.

8. A wind turbine blade (5) for the wind turbine (1), the wind turbine blade (5) extends in a longitudinal direction from a blade root (6) to a tip end (7) and in a chordwise direction from a leading edge (8) to a trailing edge (9), wherein the wind turbine blade (5) comprises a blade shell (10) defining a pressure side (11) and a suction side (12), the wind turbine blade (5) further comprises the blade root section (13) comprising the blade root (6) in which at least one of the bulkhead unit (16) is arranged, wherein said at least one of the bulkhead unit (16) is the pre-assembled unit according to claim 7.

9. A wind turbine blade (5) for a wind turbine (1), the wind turbine blade (5) extends in a longitudinal direction from a blade root (6) to a tip end (7) and in a chordwise direction from a leading edge (8) to a trailing edge (9), wherein the wind turbine blade (5) comprises a blade shell (10) defining a pressure side (11) and a suction side (12), the wind turbine blade (5) further comprises a blade root section (13) comprising the blade root (6) in which at least one bulkhead unit (16) is arranged, wherein said at least one bulkhead unit (16) comprises the bulkhead (17) according to claim 6.

10. A method of manufacturing a bulkhead unit (16) for a wind turbine blade (5), the wind turbine blade (5) extends in a longitudinal direction from a blade root (6) to a tip end (7) and in a chordwise direction from a leading edge (8) to a trailing edge (9), wherein the method comprises the steps of: manufacturing a bulkhead (17), wherein the bulkhead (17), when installed, extends in a radial direction and has at least a first side, a second side, and an outer circumference, the first and second sides face in opposite longitudinal directions and the outer circumference is arranged in a radial plane, wherein the bulkhead (17) comprises at least one bulkhead part (19, 21), wherein said at least one bulkhead part (19, 21) is manufactured by rotational moulding or vacuum forming wherein said step of manufacturing the bulkhead (17) comprises forming at least one installation opening (22) through the bulkhead (17) via moulding; and mounting or integrating at least one element (18) on the bulkhead (17) prior to installation of the bulkhead unit (16), wherein said at least one element (18) is arranged on at least one of a first side of the bulkhead and a second side of the bulkhead, the at least one element (18) engaging with the at least one installation opening (22) formed through the bulkhead (17).

Description

DESCRIPTION OF DRAWINGS

(1) The invention is explained in detail below with reference to embodiments shown in the drawings, in which

(2) FIG. 1 shows a wind turbine,

(3) FIG. 2 shows a schematic view of a wind turbine blade according to embodiments of the invention,

(4) FIGS. 3a-b show a cross section of the blade root section and two alternative first embodiments of the bulkhead unit,

(5) FIGS. 4a-b show a second embodiment of the bulkhead and two exemplary arrangements of the bulkhead parts,

(6) FIG. 5 shows a third embodiment of the bulkhead and an alternative arrangement of the bulkhead parts,

(7) FIG. 6 shows the bulkhead with pre-determined openings for mounting or installation of other elements, and

(8) FIG. 7 shows a fourth embodiment of the bulkhead with an adjustable or deformable element.

LIST OF REFERENCES

(9) 1. Wind turbine

(10) 2. Wind turbine tower

(11) 3. Nacelle

(12) 4. Hub

(13) 5. Wind turbine blades

(14) 6. Blade root

(15) 7. Tip end

(16) 8. Leading edge

(17) 9. Trailing edge

(18) 10. Blade shell

(19) 11. Pressure side

(20) 12. Suction side

(21) 13. Blade root section

(22) 14. Aerodynamic blade section

(23) 15. Transition section

(24) 16, 16′. Bulkhead unit, first bulkhead unit

(25) 17, 17′, 17″, 17′″. Bulkhead

(26) 18. Other elements

(27) 19a, 19b. Bulkhead parts

(28) 20a, 20b. Installation flanges

(29) 21a, 21b, 21c. Bulkhead parts

(30) 22. Openings for hatches

(31) 23. Openings for lightning down conductors and data cables

(32) 24. Openings for ventilation tubes and air guidance systems

(33) 25. Adjustable element

(34) 26. Deformable element

(35) The listed reference numbers are shown in abovementioned drawings where no 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

(36) 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 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. The hub 4 is connected to a drive train located in the nacelle 3 via a rotation shaft.

(37) The hub 4 comprises a mounting interface for each wind turbine blade 5. A pitch bearing unit is optionally connected to this mounting interface and further to the wind turbine blade 5.

(38) FIG. 2 shows a schematic view of the wind turbine blade 5 which extends in a longitudinal direction from a blade root 6 to a tip end 7. The wind turbine blade 5 further extends in a chordwise direction from a leading edge 8 to a trailing edge 9. The wind turbine blade 5 comprises a blade shell 10 defining a pressure side 11 and a suction side 12. The blade shell 10 further defines a blade root section 13, an aerodynamic blade section 14, and a transition section 15 between the blade root section 13 and the aerodynamic blade section 14.

(39) The blade root section 13 has a substantially circular or elliptical cross-section (indicated by dotted lines). The blade root section 13 together with the load carrying structure, e.g. the spar cap and shear webs or box, 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 11 and the suction side 12 and in the longitudinal direction.

(40) The blade aerodynamic blade section 14 has an aerodynamically shaped cross-section (indicated by dotted lines) designed to generate lift. The cross-sectional profile of the blade shell 10 gradually transforms from the circular or elliptical profile into the aerodynamic profile in the transition section 15.

(41) The wind turbine blade 5 further comprises a bulkhead unit 16 located in the blade root section 13.

(42) FIGS. 3a-b show a cross section of the blade root section 13 along the longitudinal direction, wherein a first bulkhead unit 16, 16′ is arranged at a predetermined distance from the blade root 6. At least a second optional bulkhead unit (indicated by dashed lines) can be arranged at a predetermined distance from the first bulkhead unit 16, 16′ as shown in FIGS. 3a-b.

(43) A first embodiment of the bulkhead unit 16 is further shown in FIG. 3a, wherein the bulkhead unit 16 comprises a bulkhead 17 and a number of other elements 18 mounted or integrated on the bulkhead 17. The other elements 18 can be lightning down conductors, ventilation tubes, de-icing elements, sensors, air guidance elements or other relevant elements. The bulkhead 17 acts as a support for these elements 18 during operation.

(44) The bulkhead unit 16 is positioned at a predetermined distance, e.g. between 50 centimetres and 75 centimetres, from the blade root 6. The bulkhead unit 16 is configured to substantially seal off the blade root 6 so that loose debris is prevented from entering the wind turbine blade 5 or the hub 4. The bulkhead unit 16 also functions as a work platform during maintenance or repair tasks in the hub 4 or the wind turbine blade 5.

(45) The bulkhead 17 is here manufactured as a single plate shaped element using rotational moulding. The bulkhead 17 comprises a first side facing the blade root, a second side facing the tip end 7 and a circumference facing an inner surface of the blade shell 10. The respective elements 18 can be mounted or integrated onto one or both sides of the bulkhead 17 as shown in FIG. 3a.

(46) Another first alternative embodiment of the bulkhead unit 16′ is further shown in FIG. 3b, wherein the bulkhead 17′ is here manufactured as a single plate shaped element using vacuum forming.

(47) The bulkhead 17′ comprises a number of installation flanges (similar to those shown in FIGS. 4a-b) projecting outwards the first side towards to the blade root 6. The orientation of the bulkhead unit 16′ may also be inverted so that the installation flanges projects towards the blade tip 7, as indicated in FIG. 3b. The installation flange is used to connect the bulkhead 17′ to the blade shell 10. Similar to the embodiment of FIG. 3a, the respective elements 18 can be mounted or integrated onto one or both sides of the bulkhead 17′ as shown in FIG. 3b.

(48) FIGS. 4a-b show a second embodiment of the bulkhead 17″ comprising a number of bulkhead parts 19a, 19b aligned in the axial direction. Here only two bulkhead parts are shown. FIG. 4a shows a first exemplary arrangement where the bulkhead parts 19a, 19b are arranged back-to-back and thus form a generally I-shaped structure.

(49) The bulkhead part 19a, 19b comprises an installation flange 20a, 20b projecting outwards from the first and second sides of the bulkhead 17″. Here the individual installation flanges 20a, 20b are facing away from each other. The installation flanges 20a, 20b are used to connect the bulkhead unit 17″ to the blade shell 10.

(50) FIG. 4b shows a second exemplary arrangement of the bulkhead 17″ where the bulk-head parts 19a, 19b are arranged front-to-front and thus form a generally O-shaped structure. Here the individual installation flanges 20a, 20b are facing towards each other and thus projects in an opposite direction of the first and second sides of the bulk-head 17″.

(51) The installation flanges shown in FIG. 3b and FIGS. 4a-b are here for illustrative purposes shown as a continuous flange extending along the entire circumference. However, the installation flange of FIG. 3b can have a different shape and/or size than the installation flange of FIGS. 4a-b.

(52) FIG. 5 shows a third embodiment of the bulkhead 17″′ comprising a number of bulk-head parts 21a, 21b, 21c aligned in the radial direction. Here only three bulkhead parts are shown. Each bulkhead part 21a, 21b, 21c is connected an adjacent bulkhead part 21a, 21b, 21c via matching installation flanges configured to be jointed together.

(53) The respective elements 18 can be mounted or integrated onto at least one of the bulkhead parts 19a, 19b, 21a, 21b, 21c shown in FIG. 4a-b and FIG. 5.

(54) FIG. 6 shows the bulkhead 17 with a number of predetermined openings for subsequent mounting or installation of the elements 18 after manufacturing. The openings are formed via a suitable mould with a predetermined pattern defining the shape and sizes of each opening.

(55) The bulkhead 17 comprises a first set of openings 22 configured for mounting a hatch (not shown) which provides access to the interior of the wind turbine blade 5. The bulk-head 17 further comprises a second set of openings 23 configured for mounting of lightning down conductors, data cables and other relevant electrical connections. The bulkhead 17 further comprises a third set of openings 24 configured for mounting ventilation tubes, air guidance systems and other relevant heating or cooling systems.

(56) The bulkhead unit 16 can then positioned inside the blade shell 10 and connected to the blade shell 10. After that the respective elements 18 can be connected or coupled to matching elements located in the wind turbine blade 5 or the hub 4.

(57) FIG. 7 shows a fourth embodiment of the bulkhead 17 with an adjustable element 25 or a deformable element 26. The adjustable element 25 is configured to change the outer dimensions of the bulkheadunit 16, e.g. the bulkhead 17, as indicated by the arrows. This allows for an easy positioning of the bulkhead unit 16 and enables the bulkhead unit 16 to seal off the blade root 6.

(58) The deformable element 26 is configured to deform to the contours of the inner surface of the blade shell 10 and thus seal off the blade root 6.