BLADE INSTALLATION TO AN OFFSHORE WIND TURBINE

Abstract

Method for installing a wind turbine blade to a nacelle of an offshore wind turbine, comprising the steps of: providing a vessel or barge with wind turbine blades and a blade installer unit comprising a blade receiving cart; at the offshore wind turbine, bringing a boom of the blade installer unit towards a wind turbine tower of the wind turbine; actuating a tower gripping device unit until the tower gripping device unit engages the tower; inserting a blade into the blade receiving cart, wherein the blade is in approximately horizontal position in the cart; moving the blade receiving cart up towards the upper end of the boom of the blade installer unit; rotating the blade until the blade is in approximately vertical position; moving the blade with respect to the cart until the blade engages the nacelle for coupling to the nacelle.

Claims

1. A method for installing a wind turbine blade to a nacelle of an offshore wind turbine, comprising the steps of: Providing a vessel or barge with a number of wind turbine blades and a blade installer unit comprising a blade receiving cart; At the offshore wind turbine, bringing a boom of the blade installer unit towards a wind turbine tower of the wind turbine, in particular with respect to the vessel; Actuating a tower gripping device unit until the tower gripping device unit engages the tower; Inserting a blade into the blade receiving cart, that is positioned at a distance from an upper end of the boom, wherein the blade is in approximately horizontal position in the cart; Moving the blade receiving cart up towards the upper end of the boom of the blade installer unit; Rotating the blade until the blade is in approximately vertical position; Moving the blade with respect to the cart until the blade engages the nacelle for coupling to the nacelle.

2. The method according to claim 1, wherein the boom of the blade installer unit is aligned with the wind turbine tower.

3. The method according to claim 2, wherein the aligning of the boom comprises moving the boom with respect to a deck of the vessel using a skid by which the blade installer unit is movably mounted to the deck.

4. The method according to claim 3, wherein the skid is an XY-skid allowing for longitudinal movement and transverse movement over the deck with respect to the deck.

5. The method according to claim 1, wherein the boom of the blade installer unit is provided on a cantilever, which cantilever is movable with respect to a deck of the vessel, and can, in extended position, reach beyond the deck.

6. The method according to claim 1, wherein the blade is brought into a blade receiver of the blade receiving cart by a manipulator mounted on the vessel or barge.

7. The method according to claim 1, comprising extending the boom of the blade installer unit by moving an extendable boom portion outward with respect to a base boom portion of the boom.

8. The method according to claim 7, wherein the tower gripping device unit is folded out from the boom to engage with the wind turbine tower when the boom has been extended.

9. The method according to claim 1, comprising adjusting the boom angle of the boom.

10. The method according to claim 1, wherein the vessel or barge is a jack-up vessel, wherein the jack-up vessel is in elevated position while the blade installer unit engages the wind turbine.

11. The method according to claim 1, wherein the blade is coupled to the nacelle.

12. A blade installer unit for use in the method according to claim 1, comprising the boom and the blade receiving cart.

13. A vessel or barge, provided with the blade installer unit according to claim 12.

14. The vessel or barge according to claim 13, further provided with a manipulator for inserting the blade into the blade receiving cart.

15. A combination of the vessel or barge according to claim 13, and a number of wind turbine blades, in storage positions on a deck of the vessel or barge, for installation of the blades to a nacelle of an offshore wind turbine.

16. The method of claim 6, wherein the manipulator is a deck crane.

17. The blade installer unit of claim 12, further comprising the tower gripping device unit.

18. The vessel or barge according to claim 13, which is a jack-up vessel.

19. The vessel or barge according to claim 14, wherein the manipulator is a deck crane.

Description

DESCRIPTION OF THE FIGURES

[0033] In the following, the invention will be explained further by means of a description of non-limiting examples shown in the figures, along with descriptions of examples of possible variations. The figures are schematic and merely show examples.

[0034] FIGS. 1 to 11 show perspective views, and FIG. 12 shows a side view, of a vessel with a blade installer unit, a wind turbine tower with nacelle, and a wind turbine blade, in particular illustrating subsequent stages of a blade installation method.

[0035] FIG. 1 shows the vessel 1, here a jack-up vessel, with the blade installer unit 2 in transport position, also called transit position. This is the position of the blade installer unit when the vessel is sailing. The blade installer unit can be provided forward, aft, in a corner or in the middle, at the stern, etc. As explained elsewhere herein with reference to FIG. 12, various positions on the deck 3 may be possible, and may depend on the deck arrangement. The vessel arrives at the site location where the wind turbine tower 4 and the nacelle 5 are already pre-installed.

[0036] FIG. 2 shows a different perspective view of the blade installer unit in, here, the elevated position of the jack-up vessel. The blade installer unit 2 comprises a boom 6, here an extendable boom, with a cart 7 movable over the boom. The cart here has a blade receiver 8 in which a wind turbine blade 9 can be inserted by means of the available deck crane 10. At the upper end of the boom, a wind turbine tower gripping device 11 (also denoted tower gripping device unit herein) is provided, here shown in folded position. Alternatively or additionally, such a tower gripping device may be arranged elsewhere along the boom.

[0037] FIG. 3 shows that the boom 6 is hinged towards the wind turbine tower 4. A tower strut 12 is folded out until it engages the tower and provides first support of the boom to the tower. The tower strut is optional and may be provided and/or used depending on weather conditions.

[0038] FIG. 4 shows the boom 6 in extended position by extending an extendable boom portion 6b outward with respect to, here out from, a base boom portion 6a. In the extended position, the boom reaches towards the upper end of the wind turbine, in particular further towards said upper end than in a more retracted position. However, in view of the height of the wind turbine towers, the boom may often not reach the top end of the tower.

[0039] FIG. 5 shows the tower gripping device 11, here provided at the upper end of the boom, is folded out towards an engagement position. In the engagement position, the tower gripping device engages the tower 4 and grips the tower to provide a firm support to the boom 6. In an advantageous embodiment, the tower gripping device may first be synchronized with the tower motion before engaging with the tower.

[0040] FIG. 6 shows the blade 9 being put into the blade receiver of the cart 7 by means of the available deck crane 10, for example using a conventional suspension means and method for a wind turbine blade. The blade is put in approximately horizontal position in the cart.

[0041] FIG. 7 shows that when the blade 9 is in the blade receiver of the cart 7, the crane 10 retracts. The cart can start moving upward along the boom 6.

[0042] FIG. 8 shows the cart 7 is moving upward along the boom 6, with the blade 9 in horizontal position in the blade receiver.

[0043] FIG. 9 shows the cart 7 with the blade 9 in approximately horizontal position is moving further upward, now along the extended portion 6b of the boom. Here, the cart 7 is moved onto an adapter unit 13, here a frame based adapter unit 13, which is movable along the extendable boom portion 6b and configured to receive the cart 7 thereon from when the cart 7 moved upward from the base boom portion 6a. Along the extendable boom portion 6b, the cart 7 and the adapter unit 6 can move together, wherein the adapter unit 6 can provide an intermediate interface between the extendable boom portion 6b and the cart 7. The cart 7 itself is here dimensioned for the base boom portion 6a which is here somewhat wider than the extendable boom portion 6b to allow the extendable boom portion 6b to move in the base boom portion 6a. Different solutions are possible, e.g. wherein the cart 7 itself is configured to move along boom portions of different widths, e.g. by having multiple corresponding sets of wheels.

[0044] FIG. 10 shows the cart 7 with the blade 9 in about horizontal position in the blade receiver, has reached the upper end of the boom 6, together with the adapter unit 13.

[0045] FIG. 11 shows the cart, in particular the blade receiver 8 in its upper position, being rotated to a vertical position V such that the blade 9 becomes oriented vertically allowing it to mate with the blade receiving interface of the nacelle 5, said blade receiving interface being substantially downward facing to facilitate engagement of the blade from below. Alternatively, the blade receiver 8 may rotate towards an approximately vertical position already during its upward movement along the boom. In that case, rotating of the blade receiver 8 may be done simultaneously with the upward movement of the cart. At the upper end of the boom, more precisely at the now upward facing end of the blade 9, the blade can then be fixated to the nacelle 5 by bolts. When the blade has been fixed to the nacelle, the blade receiver 8 may open and retract to release the blade. When clear of the blade, the blade receiver can rotate back to the horizontal position, and the cart 7 can move to its lower position. The nacelle 5 may then be rotated. The blade installation may be repeated until the three blades are fixed to the nacelle 5. The vessel 1, in case of a jack-up vessel, may go to floating position (see right hand side of FIG. 12) and sail to the next pre-installed wind turbine tower for the installation of the blades thereto.

[0046] FIG. 12 shows the blade 9, in vertical position V, is being pushed upward to engage with the nacelle 5. In FIG. 12, it can be seen that in this example blades 9 are stored on the deck of the vessel in an orientation parallel to a horizontal position of the blade 9 when initially received by the blade receiving cart, so that the orientation of the blade need not be altered by the deck crane 10. By contrast, in the example of FIGS. 1-11, the deck crane 10 needs to be operated to swerve the blade 9 by about 90 degrees about a vertical axis when moving the blade from its storage position S on the deck 3 to its received position R on the cart 7, see FIG. 7.

[0047] Although the invention has been explained further herein using examples and figures, these do not limit the scope of the invention as defined by the claims. Many variations, combinations and extensions are possible, as will be appreciated by the skilled person having the benefit of the present disclosure. All such variants are included within the scope of the invention as defined by the claims.