A MAINTENANCE ENCLOSURE AND METHOD FOR MAINTAINING WIND TURBINE BLADES

Abstract

Disclosed is a maintenance enclosure (1) for use when maintaining a wind turbine blade (2). The maintenance enclosure (1) comprising a ceiling (3), a floor (4) and at least two side walls (5a, 5b) extending between the ceiling (3) and the floor (4). The maintenance enclosure also comprising a first adjustable opening (6) in a first side wall (5a) of the at least two side walls (5a, 5b) adapted for receiving the wind turbine blade (2) and a second adjustable opening (7) in a second side wall (5b) of the at least two side walls (5a, 5b) adapted for receiving the wind turbine blade (2). The first adjustable opening (6) and the second adjustable opening (7) are positioned opposite each other and the said floor (4) comprises a slit (8) extending at least a portion of the distance between the first adjustable opening (6) and the second adjustable opening (7). Also, the slit (8) is adapted for receiving the wind turbine blade (2). Furthermore, a method for maintaining a wind turbine blade (2) is disclosed.

Claims

1. A maintenance enclosure for use when maintaining a wind turbine blade, said maintenance enclosure comprising: a ceiling, a floor and at least two side walls extending between said ceiling and said floor, a first adjustable opening n a first side wall of said at least two side walls adapted for receiving said wind turbine blade and a. second adjustable opening in a second side wall of said at least two side walls adapted for receiving said wind turbine blade, wherein said first adjustable opening and said second adjustable opening are positioned opposite each other, wherein said floor comprises a slit extending at least a portion of the distance between said first adjustable opening and said second adjustable opening, and Wherein said slit is adapted for receiving said wind turbine blade.

2. The maintenance enclosure according to claim 1, wherein said maintenance enclosure further comprises a blade edge support adapted for supporting said maintenance enclosure on an edge of said wind turbine blade.

3. The maintenance enclosure according to claim 1, wherein said maintenance enclosure is formed elongated and wherein said first side wall and said second side wall are positioned in opposite ends of said elongated maintenance enclosure.

4. The maintenance enclosure according to claim 1, wherein said maintenance enclosure is formed as a parallelepiped, wherein each angle is a 90-degree angle.

5. The maintenance enclosure according to claim 1, wherein said maintenance enclosure is an ISO-container comprising a. corner casting in each corner of said ISO-container.

6. The maintenance enclosure according to claim 1, wherein said slit extends along a longitudinal direction of said maintenance enclosure.

7. The maintenance enclosure according to claim 1, wherein said slit extends the entire length of said floor.

8. (canceled)

9. The maintenance enclosure according to claim 1, wherein said maintenance enclosure comprises blade positioners adapted for maintaining the mutual position between said maintenance enclosure and said wind turbine blade in the horizontal direction.

10-11. (canceled)

12. The maintenance enclosure according to claim 1, wherein said maintenance enclosure comprises lifting lugs on the outer side.

13. The maintenance enclosure according to claim 1, wherein said first adjustable opening and/or second adjustable opening comprises a sealing element adaptable to the shape of at least a part of the circumference of said wind turbine blade.

14. (canceled)

15. The maintenance enclosure according to claim 1, wherein the length of said maintenance enclosure is between 4 and 30 meters, preferably between 6 and 22 meters and most preferably between 8 and 16 meters, wherein the width of said maintenance enclosure is between 1 and 10 meters, preferably between 2 and 8 meters and most preferably between 3 and 6 meters, wherein the height of said maintenance enclosure is between 0.5 and 8 meters, preferably between 1 and 6 meters and most preferably between 2 and 5 meters.

16. The maintenance enclosure according to claim 1, wherein said maintenance enclosure comprises positioning actuators for bringing said maintenance enclosure into alignment with said wind turbine blade.

17. (canceled)

18. The maintenance enclosure according to claim 1, wherein said maintenance enclosure comprises guiders at said floor arranged to guide said wind turbine blade into said slit.

19. The maintenance enclosure according to claim 1, wherein said maintenance enclosure comprises lifters inside said maintenance enclosures.

20. A method for maintaining a wind turbine blade said method comprising the steps of: positioning a wind turbine blade of a wind turbine in a substantially horizontal position, lifting a maintenance enclosure onto said wind turbine blade so that said wind turbine blade penetrates the floor and at least one side wall of said maintenance enclosure, performing maintenance on said wind turbine blade from inside of said maintenance enclosure.

21. The method according to claim 15, wherein said method comprises the step of fixating the position of said maintenance enclosure relation to said wind turbine blade before performing said maintenance.

22. The method according to claim 15, wherein said wind turbine blade is positioned with a leading edge of said wind turbine blade facing upwards.

23. The method according to claim 15, wherein said maintenance enclosure is lifted onto said wind turbine blade by way of a crane.

24. The method according to claim 15, wherein said method further comprises the step of guiding said maintenance enclosure onto said wind turbine blade by way of positioning actuators capable of adjusting the position and/or orientation of said maintenance enclosure in the horizontal plane.

25. The method according to claim 15, wherein said method further comprises the step of sealing a gap between said wind turbine blade and said floor and/or between said wind turbine blade and said at least one sidewall after lifting a maintenance enclosure onto said wind turbine blade.

26-27. (canceled)

Description

FIGURES

[0077] The invention will be described in the following with reference to the figures in which

[0078] FIG. 1. illustrates a maintenance enclosure enclosing a part of a wind turbine blade as seen in perspective,

[0079] FIG. 2 illustrates a maintenance enclosure enclosing a part of a wind turbine blade as seen from the side,

[0080] FIG. 3 illustrates a maintenance enclosure as seen in a first perspective view,

[0081] FIG. 4 illustrates a maintenance enclosure as seen in a second perspective view,

[0082] FIG. 5 illustrates a maintenance enclosure as seen from the front,

[0083] FIG. 6 illustrates a right section of a maintenance enclosure as seen in perspective,

[0084] FIG. 7 illustrates a left section of a maintenance enclosure as seen in perspective,

[0085] FIG. 8 illustrates a different configuration of a maintenance enclosure enclosing a part of a wind turbine blade as seen in perspective,

[0086] FIG. 9 illustrates a different configuration of a maintenance enclosure enclosing a part of a wind turbine blade as seen

[0087] FIG. 10 illustrates a different configuration of a maintenance enclosure enclosing a part of a wind turbine blade as seen from the top,

[0088] FIG. 11 illustrates an embodiment of the maintenance enclosure formed as a container and positioned at the tip of the blade as seen in perspective,

[0089] FIG. 12 illustrates an embodiment of the maintenance enclosure formed as a container and positioned at a substantially middle part of the blade as seen in perspective,

[0090] FIG. 13 illustrates a cross-sectional view of the wind turbine blade, and

[0091] FIG. 14 illustrates a wind turbine.

DETAILED DESCRIPTION

[0092] FIGS. 1-2 illustrate a maintenance enclosure 1 enclosing a part of a wind turbine blade 2 as seen in perspective and from the side, respectively.

[0093] It should be noted that the wind turbine blade 2 is mounted on a wind turbine throughout all the figures although this is not shown in the figures for the sake of simplicity. Furthermore, it should be noted that orientation terms such as, horizontal, vertical, up and down should be understood in relation to the maintenance enclosure in operational position, i.e. when the floor 4 of the maintenance enclosure 2 is substantially parallel with a wind turbine blade 2 in horizontal position or close to horizontal position when mounted on a wind turbine.

[0094] At some point in the lifetime of the wind turbine blade 2, maintenance must be performed due to e.g. cracks initiating from fatigue loads and the wear on the leading edge 10 of the wind turbine blade 2 due to collision with e.g. rain drops. The maintenance enclosure 1 as disclosed in FIGS. 1-2 is adjusted such that the it is slightly tilted in relation to horizontal such that the floor 4 is substantially parallel with the trailing edge 27 of the wind turbine blade. Thus, the vertical position of the maintenance enclosure may be adjusted by adjusting the blade edge support 9. This may be beneficial if e.g. vortex generators, flaps, low-pressure side, high-pressure side 25 or trailing edge maintenance is necessary in that the access to the entire wind turbine blade surface of a given section may be accessed.

[0095] The maintenance personnel may be present inside the maintenance enclosure 1 during the process of lifting the maintenance enclosure 1 up and onto the wind turbine blade 2. They may also be transported to and from the maintenance enclosure e.g. with a helicopter or other means for transporting people after the maintenance enclosure 1 has been positioned on the blade 2.

[0096] In this embodiment the maintenance enclosure 1 is lifted onto the wind turbine blade 2 by means of a telescopic crane (not shown). However, in another embodiment, the maintenance enclosure 1 could be lifted by using a helicopter, one or more drones, a forklift machine, a mobile crane, crawler crane or any other means for lifting the maintenance platform onto the wind turbine airfoil. The maintenance platform 1 may also be self-propelled e.g. by comprising nozzles or propellers at the bottom (or at the top) which lift the maintenance platform 2 upwards.

[0097] When the maintenance enclosure 1 must be repositioned in order to perform maintenance work or service on another section of the wind turbine blade 2, the repositioning is performed by e.g. a crane (not shown) which lifts the maintenance enclosure 1 free from the blade 2 where after it is moved along the blade. However, in an embodiment the maintenance enclosure 1 may comprise driving means (not shown) for moving the maintenance enclosure 1 along the blade 2 without the aid of a lifting crane such that it is self-propelled. The driving means could comprise wheels, a pulley system, caterpillar tracks or any other kind of driver suitable for moving the maintenance enclosure 1 along the blade 2.

[0098] In this embodiment, the first side wall 5a and second side wall 5b comprises a series of struts. However, in another embodiment, the first side wall 5a and/or the second sidewall 5b could comprise a solid wall (see for example FIG. 11 and FIG. 12), glass panes, a grate, railing, metal shell or any other type of wall for enclosing the maintenance enclosure 1. Also, in this embodiment, the first side wall 5a and second side wall 5b are positioned on opposite ends of the elongated maintenance enclosure 1.

[0099] In an embodiment, the maintenance enclosure may be completely or partly enclosed by a tarp and it could be open to the sides and/or the top and/or it could be partly open to the sides and/or the ceiling.

[0100] As an exemplary embodiment the maintenance work could be performed according to the method comprising the steps of [0101] positioning a wind turbine blade 2 of a wind turbine 28 in a substantially horizontal position by rotating the relevant blade 2 to a substantially horizontal position by using e.g. gearing mechanism and motors already present in the wind turbine 28. In some embodiments of the method the blade could also be locked in the substantially horizontal position by locking the gearing of the wind turbine or using external equipment for locking rotation of the blade 2. [0102] lifting a maintenance enclosure onto the wind turbine blade 2 so that the wind turbine blade 2 penetrates the floor 4 and at least one side wall 5a or 5b of the maintenance enclosure 1. The enclosure 1 could be lifted onto the blade 2 by using a crane (not shown) or it could be lifted by using other kinds of tools or machinery. [0103] performing maintenance on the wind turbine blade 2 from inside of the maintenance enclosure.

[0104] FIG. 3-4 illustrates a maintenance enclosure 1 as seen in perspective.

[0105] Some maintenance work may only require service or maintenance on the tip of the wind turbine blade 2. Therefore, the maintenance enclosure only encloses the tip of the wind turbine blade 2 (see for example FIG. 10, FIG. 11 and FIG. 13). Accordingly, the wind turbine blade 2 does not necessarily protrude through the second adjustable opening 7. Therefore, the second adjustable opening 7 is in this embodiment a sliding door 11 which may easily be opened and closed depending on operational requirements. However, in another embodiment, the first adjustable opening and/or the second adjustable opening 7 could comprise an air cushion, a swinging door or a hatch.

[0106] In this embodiment, the blade edge support 9 is a rack shaped in the form of a “V”. However, in another embodiment the blade edge support 9 could comprise a frame, rods, beams, spring suspension or other kind of structure for supporting a part of the load from the main enclosure 2 on the leading edge 10 of the blade 2.

[0107] Also, some maintenance work may require drilling, welding, gluing, soldering or other kind of process which may develop toxic smoke or fumes which may be harmful to the maintenance personnel if exposed to for large periods of time. Therefore, the maintenance enclosure 1 may comprise a ventilation system 26. The maintenance enclosure 1 may further comprise a climate control system or a dehumidifier for adjusting the environment inside the maintenance enclosure 1. Said systems could be separate systems or combined into one system.

[0108] The maintenance enclosure 1 may be provided with different kinds of monitoring systems. For example, the maintenance enclosure 1 may be provided with anemometers for monitoring wind speeds and thereby provide the maintenance personnel with warning signs if the wind speed exceeds a critical speed at which it may not be safe to stay in the maintenance enclosure 1. Also, in such situations, a quick evacuation route may be urgent. Thus, in an embodiment, the maintenance enclosure 1 may comprise means for evacuating the personnel such as inflatable evacuation slide, evacuation capsule, inflatable evacuation channel or other kind of evacuation systems. Other emergency equipment which may be comprised in the maintenance enclosure could be fire extinguishers, first aid kit and other.

[0109] Generally, the maintenance enclosure 1 may comprise different kind of tools necessary for performing the maintenance work such as compressors, drills, screw drivers, high pressure cleaners, tools boxes etc.

[0110] FIG. 5 illustrates a maintenance enclosure 1 as seen from the side.

[0111] Maintenance work on a wind turbine blade 2 may require heavy duty tools, power tools, heavy replacement parts or other objects, which may be troublesome to move around. Thus, the maintenance enclosure 1 may comprise lifting means 21 for lifting these objects. In this embodiment, the lifting means 21 is a traverse crane. However, in another embodiment, the lifting means 21 could be a pulley system, a robot arm, boom arm or other kind of lifting structure which may be attached to the ceiling 3.

[0112] In this embodiment, the slit 8, as shown in FIG. 5, has a rectangular geometry. However, in another embodiment, the base shape of the slit 8 could be triangular, circular, polygonal or any other shape which may form a slit and may be suitable for receiving a wind turbine blade 2. Also, the slit 8 may be at least partly covered by a roll out tarpaulin, a hatch or similar covering means as precautionary measure if for example the maintenance enclosure is to be shipped to another site or when not in operation.

[0113] The maintenance enclosure 1 may comprise guide means 20 for directing and guiding the blade 2 into the slit 8 such that blade 2 is partly or fully received in the slit 8. In this embodiment, the guide means 20 comprises wheels. In another embodiment the guide means 20 could also comprise a suspension mechanism for absorbing any minor collision between the guide means 20 and the wind turbine blade 2 which may occur when the enclosure 1 is lifted onto the wind turbine blade 2. In another embodiment, the guide means 20 could comprise a narrowing-down channel and the edge of the floor could also be tapered so that the blade is guided into the slit 8.

[0114] In an embodiment, the maintenance enclosure 1 may comprise a battery pack (not shown) for providing energy to computer systems, tools, ventilation system or other energy consuming apparatus in the maintenance enclosure 1.

[0115] To ensure light-weight construction, the maintenance enclosure 1 comprises steel or aluminum frame. However, in an embodiment the frame could comprise e.g. composite materials or polymer materials. The main frame of the maintenance enclosure 1 could also comprise 3D printed parts.

[0116] FIG. 6-7 illustrate two different section views of a maintenance enclosure 1.

[0117] In the embodiment as disclosed in FIG. 7, the blade positioning means 12 comprises suction cups 13. However, in another embodiment, the blade positioning means 12 could comprise an expanding wall 14 (e.g. an inflatable cushion), supporting struts, a movable wall, a wedge, a fender or any other kind of structure or mechanism suitable for positioning and/or fixating the wind turbine blade inside the maintenance enclosure 2. The enclosure 1 may comprise blade positioning means 12 on one side or on both sides of the slit 8. The blade positioning means 12 may be fixed or movable in the horizontal direction to adapt them to the curvature and/or width of the blade.

[0118] In this embodiment, the first side wall 5a and second side wall 5b are straight walls. However, in another embodiment, the sidewalls could be bent, curved, wave-shaped or any other shape which may be structurally or aerodynamically optimized for preventing buckling of the maintenance enclosure or for withstanding wind loads.

[0119] In this embodiment, the sealing element 16 comprises an air cushion 17. However, in another embodiment, the sealing element 16 could comprise a gate of brushes as known from door seals, a rubber seal, a wedge-shaped polymer seal, a pad or any other kind of seal which is adaptable to a part of the circumference of the wind turbine blade and which provides for a sealing effect. The air cushion 17 may provide for a sealing element 16 for providing a firm seal between the wind turbine blade 2 and the first wall 5a of maintenance enclosure 1 such that the maintenance enclosure 1 and the wind turbine blade 2 are firmly secured in relation to each other. The sealing element 16 may also provide for sealing against e.g. wind, rain, snow and dust which may leak into the maintenance enclosure 1 and affect the working environment or function of the maintenance enclosure 1.

[0120] FIG. 8-10 illustrates a different configuration of a maintenance enclosure 1 enclosing a wind turbine blade 2 as seen in perspective, from the side and from the top, respectively.

[0121] The leading edge 10 of the blade 2 is exposed to heavy wear. Therefore, the main part of the maintenance work is performed on this region of the wind turbine blade 2 and the figures therefore illustrate maintenance enclosure 1 which encloses a wind turbine blade 2 with the leading 10 facing upwards. However, the maintenance enclosure 1 may also be lifted onto the blade with the trailing edge 27 facing upwards. Thus, the maintenance enclosure is also suitable for performing maintenance on the wind turbine blade 2 with the trailing edge 27 pointing upwards.

[0122] In this embodiment, the slit 8 extends in the entire longitudinal direction of the maintenance enclosure 1. However, in another embodiment, the slit 8 could extend in an angled direction or transverse direction. Also, in an embodiment, the slit 8 extends only a part of the length of the floor 4 e.g. if the maintenance enclosure 1 was initially placed vertically down onto the tip of the blade 2 and subsequently moved horizontally along the blade 2.

[0123] FIG. 11-12 illustrates an embodiment of the maintenance enclosure 1 formed as a container and positioned at the tip of the blade as seen in perspective.

[0124] The maintenance platform may be used for offshore wind turbines as well as onshore wind turbines and depending on the site, wind currents may shift and rotate the maintenance platform 1 in the air as it is lifted onto the wind turbine blade 2. Therefore, in an embodiment (as disclosed in FIG. 12), the maintenance enclosure may comprise propellers 19 for adjusting the position and counter-act the wind shear. And in another embodiment the positioning means 18 could comprise nozzles, a wire system, flap or other kind of means for adjusting the orientation and/or position of the maintenance enclosure 2.

[0125] Due to the design of the maintenance enclosure 1 it may operate at any given time of the day or year. However, it may often be used in daylight rather than in times of dark. Therefore, the maintenance enclosure may be provided with window panes 23 for increasing the natural light inside the maintenance enclosure and also for reducing the energy which is spent on artificial lightning. To further increase the efficiency of the maintenance enclosure 1, it may be advantageous to provide solar cells 22 on the ceiling 3 such that the maintenance enclosure 1 may be self-sustained (or at least more).

[0126] In this embodiment, the maintenance enclosure 1 is elongated and rectangular with 90-degree angles. However, in another embodiment, the maintenance enclosure may be triangular, circular, polygonal, parallelepiped with angles other than 90-degree or any other shape.

[0127] In this embodiment, the maintenance enclosure 1 may be an ISO-container with standard dimensions comprising corner castings in each corner. If the maintenance enclosure 1 is an ISO-container it may be easier to stack and ship the enclosure(s) to different sites by using standard container ships. In another embodiment the maintenance enclosure 1 may also comprise an ISO-container with lifting lugs 15 as shown in FIG. 12 instead of/in combination with standard corner castings.

[0128] Also, in the embodiment of FIG. 12, the maintenance enclosure is lifted via the lifting lugs 15. However, in another embodiment, the maintenance platform 1 may comprise channels for receiving forks, a hook, corner casting or other kind of part which may be used for lifting the maintenance enclosure 1.

[0129] Although it is safest to suspend the maintenance enclosure 1 on a lifting crane at all times, the maintenance enclosure 1 may, in an embodiment, be supported entirely by the wind turbine blade 2.

[0130] FIG. 13 illustrates a cross-sectional view of the wind turbine blade 2.

[0131] The airfoil 2 is shaped such that it generates a pressure difference between the high-pressure side 25 and the low-pressure side 24 when the air flows from the leading edge 10 to the trailing edge 27 whereby an aerodynamic force is produced which generates lift.

[0132] FIG. 14 illustrates a wind turbine 28.

[0133] The wind turbine 28 could be an offshore wind turbine or an onshore wind turbine on which wind turbine blades 2 may be serviced by using the maintenance enclosure 1 according to an embodiment of the invention.

[0134] The invention has been exemplified above with reference to specific examples of blade edge support 9, blade positioning means 12, sealing element 16 and other. However, it should be understood that the invention is not limited to the particular examples described above but may be designed and altered in a multitude of varieties within the scope of the invention as specified in the claims.

LIST

[0135] 1. Maintenance enclosure [0136] 2. Wind turbine blade [0137] 3. Ceiling [0138] 4. Floor [0139] 5a. First side wall [0140] 5b. Second side wall [0141] 6. First adjustable opening [0142] 7. Second adjustable opening [0143] 8. Slit [0144] 9. Blade edge support [0145] 10. Leading edge [0146] 11. Sliding door [0147] 12. Blade positioning means [0148] 13. Suction cups [0149] 14. Expanding walls [0150] 15. Lifting lugs [0151] 16. Sealing element [0152] 17. Air cushions [0153] 18. Positioning means [0154] 19. Propellers [0155] 20. Guide means [0156] 21. Lifting means [0157] 22. Solar cell [0158] 23. Window pane [0159] 24. Low-pressure side [0160] 25. High-pressure side [0161] 26. Ventilation system [0162] 27. Trailing edge [0163] 28. Wind turbine