HANDLING ARRANGEMENT

Abstract

A handling arrangement for handling a wind turbine rotor blade includes a frame assembly realized to fit about the airfoil of the rotor blade; a number of add-on covers arranged to fit between the frame assembly and the airfoil surface, wherein an add-on cover is shaped to fit around a number of add-ons; and a load-bearing material for filling the add-on cover when the add-on cover is pressed against the rotor blade. A method of handling a wind turbine rotor blade is also provided.

Claims

1. A handling arrangement for handling a wind turbine rotor blade, comprising: a frame assembly configured to fit about an airfoil of the rotor blade; a plurality of add-on covers arranged to fit between the frame assembly and an airfoil surface, wherein an add-on cover is shaped to fit around the plurality of add-ons; and an essentially non-compressible load-bearing material for filling the add-on cover when the add-on cover is pressed against the rotor blade.

2. The handling arrangement according to claim 1, wherein an add-on cover comprises a rigid housing adapted for mounting to the frame assembly.

3. The handling arrangement according to claim 1, wherein an add-on cover comprises a seal arranged about a perimeter of a housing.

4. The handling arrangement according to claim 3, wherein the seal is an inflatable chamber, a flexible lip, or a gasket.

5. The handling arrangement according to claim 3, wherein the seal is shaped to face inwards.

6. The handling arrangement according to claim 1, wherein the load-bearing material comprises a particulate, a gel, a colloid, or a liquid.

7. The handling arrangement according to claim 1, wherein the load-bearing material is water-soluble and/or non-adhesive.

8. The handling arrangement according to claim 1, wherein an add-on cover comprises a port for conveying the load-bearing material into a cavity when the add-on cover is pressed against the rotor blade.

9. The handling arrangement according to claim 1, wherein an add-on cover is arranged for placement along a region of maximum thickness of the airfoil.

10. A method of handling a wind turbine rotor blade equipped with surface add-ons, of the method comprising: arranging the rotor blade with an airfoil in an essentially horizontal orientation; arranging a frame assembly of a handling arrangement about the airfoil of the rotor blade; arranging an add-on cover of the handling arrangement around a plurality of add-ons; pressing the add-on cover against the rotor blade; and filling a non-compressible load-bearing material into the add-on covers of the handling arrangement.

11. The method according to claim 10, further comprising connecting the handling arrangement to a hoisting apparatus and lifting the rotor blade to a height of a hub.

12. The method according to claim 10, further comprising initially arranging the rotor blade with a suction side facing downwards.

13. The method according to claim 10, wherein the pressing the add-on cover against the rotor blade precedes the filling the load-bearing material into the add-on cover.

14. The method according to claim 10, further comprising introducing a granulate material and a liquid into the add-on cover such that the load-bearing material comprises a granulate and a liquid.

15. The method according to claim 10, wherein the arranging the frame assembly about the airfoil is carried out after a final manufacturing stage of the rotor blade, and the add-on cover is released after installation of the rotor blade to a hub of a wind turbine.

Description

BRIEF DESCRIPTION

[0027] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0028] FIG. 1 illustrates a stage in a method of handling a wind turbine rotor blade;

[0029] FIG. 2 shows a rotor blade of the wind turbine having an arrangement of add-ons on a suction side, in accordance with an embodiment of the present invention;

[0030] FIG. 3 shows an exemplary wind turbine rotor blade;

[0031] FIG. 4 shows an embodiment of the handling apparatus during a handling, transport or lifting stage;

[0032] FIG. 5 shows a protective cup according to an embodiment of the present invention;

[0033] FIG. 6 shows a protective cup according to another embodiment of the present invention;

[0034] FIG. 7 shows a perspective view of a protective cup according to an embodiment of the present invention; and

[0035] FIG. 8 shows details of exemplary embodiments of the inventive handling arrangement.

DETAILED DESCRIPTION

[0036] FIG. 1 shows a wind turbine rotor blade 20 during an installation procedure. The rotor blade 20 is being hoisted to the level of the hub 21 of an offshore wind turbine, so that its root end 20R can be attached to the hub 21. A handling arrangement 1 holds the rotor blade 20 as shown, i.e. with its airfoil 20A in an essentially horizontal orientation, and this handling arrangement 1 is hoisted by a crane (only partially shown), for example a crane on an installation vessel in the case of an offshore wind turbine.

[0037] Each rotor blade 20 of the wind turbine 2 has an arrangement of add-ons 200 on its suction side 20S, as shown in the exemplary embodiment illustrated by FIG. 2. The add-ons 200—in this case vortex generators—are arranged essentially parallel to the leading edge LE and serve to improve the aerodynamic performance of the rotor blades 20. Of course, the rotor blade may be equipped with other further arrangements of add-ons, and may also have add-ons on its pressure side.

[0038] During the lifting procedure, the rotor blade can be held with its suction side 20S facing downwards. This is to avoid unfavorably large lift forces that would be caused by airflow over the rotor blade 20, as will be known to the skilled person, especially if the leading edge LE faces into the wind. However, as shown in FIG. 3, a favored location for add-ons 200 is in line with a structurally reinforcing web 20W arranged in the rotor blade interior. This position is therefore also the most suitable location for placing a pad of a handling arrangement. Conventionally, the solution has been to omit a sufficient number of add-ons to leave a gap for a lifting apparatus pad (with an associated reduction in aerodynamic efficiency), or to construct a pad for placement to one or both sides of the add-ons (thereby risking damage to the rotor blade).

[0039] The inventive handling arrangement 1 is constructed to be able to grasp the rotor blade 20 without damaging any of the add-ons 200. This is illustrated in FIG. 4, which shows the handling arrangement 1 in place about a rotor blade 20, which is oriented so that its suction side 20S faces downward. In this exemplary embodiment, the handling arrangement 1 comprises a frame assembly 11 realized to fit about the airfoil 20A of the rotor blade 20, and to clamp the rotor blade 20 between pads 10, 11P in a region near the center of mass of the rotor blade 20. Here, the pads 10, 11P are essentially in line with the structurally reinforcing web 20W in the rotor blade interior. The diagram shows a protective cup 10 arranged to fit between the frame assembly 11 and the airfoil surface of the downward-facing suction side 20S, and a further pad 11P arranged to fit between the frame assembly 11 and the airfoil surface of the upward-facing pressure side 20P. The protective cup 10 has a rigid housing 10H that is shaped to define a volume or cavity 10C which encloses or surrounds one or more add-ons 200 protruding from the airfoil surface. The cavity 10C defined by the housing 10H and the airfoil surface is filled with a non-compressible load-bearing material M. A seal 10S arranged about the perimeter of the housing 10H ensures that the load-bearing material M cannot escape during the lifting procedure. The frame assembly 11 of the handling arrangement 1 is connected by means of an outer structure 12 and lifting eyelet 13 to a hoisting apparatus such as a crane. The frame assembly 11 can be opened and closed by means of remote control, as will be known to the skilled person.

[0040] FIG. 5 shows a protective cup 10 in one possible embodiment of the invention. Here, the protective cup 10 is filled with the chosen load-bearing material M before being pressed against the airfoil surface 20S. The diagram shows the rotor blade 20 arranged so that a surface with add-ons 200 is arranged to face downwards. In this exemplary embodiment, the seal 10S is realized as an inflatable chamber or tube which, when inflated, will conform to the surface of the rotor blade.

[0041] FIG. 6 shows a further possible embodiment of the invention. The rotor blade 20 is arranged so that a surface carrying add-ons 200 faces upwards. A protective cup 10 mounted on the frame of the handling arrangement 1 is arranged in place about a group of add-ons 200. The frame assembly is clamped about the rotor blade 20 so that pressure is applied to press the seal 10S against the rotor blade surface. In this exemplary embodiment, the protective cup 10 is equipped with a port 10P through which the load-bearing material M can be introduced to fill the cavity 10C. In this exemplary embodiment, the seal 10S is realised as a flexible lip which, when pressed against the rotor blade, will conform to the surface of the rotor blade. In this case, the seal 10S faces inwards, so that the filler M will press against the seal 10S, causing it to make optimal contact with the rotor blade surface during the entire handling procedure, thereby increasing the effectiveness of the seal 10S. The load-bearing material M can be sand, water, a gel, a colloid, etc. For example, sand can be filled into the protective cup 10. With sand (or any comparable granulate material) as a filler, the protruding add-ons can bury into the granulate. When the cover is pressed against the airfoil surface, the granulate contacts the rotor blade surface. The grains of sand are pressed together, making contact by virtue of their many surfaces, and can therefore very effectively transfer the downward load to the frame assembly when the rotor blade is being lifted, while the add-ons are not subject to any loading and are optimally protected from damage. The filler can simply be dry sand, or a quantity of water can be added to form a colloid filler and to further improve the effectiveness of load transfer within the cup.

[0042] A combination of insoluble granulate and water can advantageously reduce the lateral forces on the seal, and can be the preferred choice of filler in the case of relatively robust add-ons. More vulnerable add-ons may benefit from a dry granulate or other filler such as a gel or colloid.

[0043] Alternatively, as explained above, the load-bearing material M can be any particulate or granular material that is essentially non-compressible and which will not adhere to the rotor blade, i.e. a material that will detach from the rotor blade 20 without any assistance. For example, a water-based gel may simply slide off the rotor blade 20 or may be washed off by rain. The materials mentioned above are non-polluting and do not present any environmental risk.

[0044] Of course, the features of the embodiments described above—i.e. the choice of seal, the choice of filler, etc. can be combined or exchanged in any reasonable manner.

[0045] FIG. 7 shows a perspective view of a protective cup 10 as described above. The diagram shows the housing 10H and the seal 10S about the perimeter of the housing 10H. A group of vortex generators 200 is indicated by dotted lines, and the diagram shows how these will be safely enclosed by the filler M when the cup 10 is put into place about the vortex generators 200. The load-bearing material M will be prevented from escaping from the cup 10 when the seal 10S is pressed against the rotor blade surface.

[0046] FIG. 8 shows a further possible embodiment of the invention. Here, the rotor blade 20 has add-ons 200 on its suction side 20S and also on its pressure side 20P. The handling arrangement 1 is equipped with appropriately arranged protective cups 10 for placement over the add-ons on the suction side 20S and also on the pressure side 20P, so that the add-ons 200 remain undamaged during handling of the rotor blade. In this embodiment, two protective covers 10 are provided for each of the suction side 20S and the pressure side 20P.

[0047] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention. For example, the filler material can be collected after completion of a handling maneuver, for example by extracting the material through a port and conveying it to a storage container.

[0048] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.