DK201671003A1

DK201671003A1 - Method and apparatus for installing and servicing wind turbine generators

Info

Publication number: DK201671003A1
Application number: DKPA201671003A
Authority: DK
Inventors: Michael Kastrup; Kim Bredo Rahbek
Original assignee: Vestas Wind Sys As
Priority date: 2016-12-19
Filing date: 2016-12-19
Publication date: 2017-11-20

Abstract

Apparatus for installing and/or servicing a wind turbine generator comprises a balloon inflated with a gas having a density less than atmospheric air, a plurality of tethering lines attached to the balloon and anchoring the balloon to ground, and a winch movably mounted to the balloon for movement in a horizontal direction. A method of installing and/or servicing a wind turbine generator is also disclosed.

Description

METHOD AND APPARATUS FOR INSTALLING AND SERVICING WIND TURBINE GENERATORS

Technical Field [0001] This invention relates generally to wind turbine generators, and more particularly to equipment for installing and servicing wind turbine generators.

Background [0002] Wind turbine generators are used to produce electrical energy using a renewable resource and without combusting a fossil fuel. A wind turbine generator converts kinetic energy from the wind into electrical energy. A horizontal-axis wind turbine generator includes a tower, a nacelle mounted atop the tower, a rotor hub rotatably supported by the nacelle, and a plurality of rotor blades attached to the hub. The hub is coupled with a generator housed inside the nacelle. Consequently, as wind forces the blades to rotate, electrical energy is produced by the generator.

[0003] Wind turbine generators are quite large, with the largest having a hub height or nacelle height well in excess of 100 meters. In addition, the various main components of the wind turbine generator, to include the generator, gearbox, transformer, main shaft, main shaft bearing, and hub, are quite heavy. Consequently it is a challenge to install and service these heavy components at such heights.

[0004] Cranes are often needed to install and service wind turbine generators. As can be imagined, ground supported cranes tall enough and strong enough to install and service wind turbine generators are extremely costly to purchase or lease, transport to the site, assemble, use, disassemble, and transport away from the site. Sometimes a temporary crane or winch is installed or rigged to the nacelle, for servicing components, but of course such is of no help in the original installation of the nacelle. Moreover, the lifting capacity of a nacelle crane or winch may be limited, especially with regard to larger components such as transformer, PCM, generator, mainshaft, gearbox and such like. Besides which, some wind turbine designs are being configured with only a very small nacelle winch or crane, for cost reasons.

[0005] Accordingly, there exists a need for a less expensive means of installing or servicing wind turbine generators.

Summary [0006] In one aspect, apparatus for installing and/or servicing a wind turbine generator is provided. The apparatus comprises a balloon inflated with a gas having a density less than atmospheric air, a plurality of tethering lines attached to the balloon and anchoring the balloon to ground, and a winch movably mounted to the balloon for movement in a horizontal direction.

[0007] The winch can be movably mounted to the balloon for movement in a horizontal plane.

[0008] The balloon can have a longitudinal extent and a lateral extent, and the winch can be movably mounted to the balloon for horizontal movement along the longitudinal extent and the lateral extent.

[0009] The balloon can include a two-axis gantry mounted to an underneath side thereof, with the winch mounted to the gantry. The gantry can provide the horizontal movement of the winch along the longitudinal extent and the lateral extent.

[0010] The gantry can comprise one or more longitudinal rails, such as a pair of longitudinal rails, a lateral rail spanning between e.g. a pair of longitudinal rails, the lateral rail having opposite ends each of which is movably mounted to one or more of the longitudinal rails, the winch movably mounted to the lateral rail for movement along the lateral rail.

[0011] The rails can be fabricated of carbon fiber material. The lateral rail can be movably mounted to the longitudinal rails via rollers. The winch can be movably mounted to the lateral rail via rollers. The tethering lines can be any appropriate type of tethering or anchoring cable known in the art such as in particular steel cables or synthetic material cables. Cables may also be fabricated of one or more material selected from a group consisting of polyamide, Kevlar, Spectra, and Dyneema.

[0012] In another aspect, a method of installing and/or servicing a wind turbine generator is provided. The method comprises providing an inflatable balloon having a winch movably mounted thereto, tethering the balloon to ground with a plurality of tethering lines, inflating the balloon with a gas having a density less than atmospheric air to elevate the balloon, raising or lowering a first wind turbine generator component with the winch, and moving the winch in the horizontal direction so as to move the first wind turbine generator component in the horizontal direction. Preferably, the aforementioned step of moving the winch in the horizontal direction may be carried out while maintaining the tethered balloon immobile or substantially immobile. In particular, the spatial position of the tethered balloon may be maintained in a fixed relation to e.g. a relevant wind generator or wind generator construction site. Preferably servicing or construction operations using the movable winch of the tethered balloon may be carried out while keeping the balloon immobile. The term “immobile” in this context is intended to indicate that horizontal movement of the relevant component being lifted is effected entirely or primarily by horizontal movement of the balloon winch. Horizontal movement of the winch may in particular include lateral and/or longitudinal movement in relation to the balloon.

[0013] The step of moving the first wind turbine generator component in the horizontal direction can allow the first wind turbine generator component to clear a second wind turbine generator component.

[0014] In another aspect, a method of installing and/or servicing a component of an existing wind turbine generator having a tower and a nacelle mounted atop the tower is provided. The method comprises providing an inflatable balloon having a winch movably mounted thereto, tethering the balloon to ground with a plurality of tethering lines, inflating the balloon with a gas having a density less than atmospheric air to elevate the balloon to a position above the nacelle, raising or lowering the wind turbine generator component with the winch, and moving the winch in the horizontal direction so as to move the wind turbine generator component in the horizontal direction to thereby clear the nacelle.

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the summary of the invention given above, and the detailed description of the drawings given below, serve to explain the principles of the present invention.

Brief Description of the Drawings [0016] Fig. 1 is a perspective view of apparatus according to the present invention.

[0017] Fig. 2 is a perspective view similar to Fig. 1 but prior to inflation of a balloon of the apparatus.

[0018] Fig. 3 is perspective view similar to Fig. 1 illustrating use of a winch mounted to the balloon to raise a wind turbine generator component up to the nacelle.

[0019] Fig. 4 is a perspective view of the balloon of Figs. 1-3 illustrating a two-axis gantry mounted to the balloon and which carries the winch.

[0020] Fig. 5 is an enlarged perspective view of Fig. 4.

Detailed Description [0021 ] Referring to Fig. 1, a wind turbine generator 10 includes a tower 12, a nacelle 14 mounted atop the tower 12, a rotor hub 16 rotatably supported by the nacelle 14, and a plurality of rotor blades 18 mounted to the hub 16. The hub 16 is operatively coupled to a generator (not shown) housed inside the nacelle 14. In addition to the generator, the nacelle 14 also houses other components required for converting wind energy into electrical energy such as a gearbox, a transformer, a main shaft, a main shaft bearing, etc. (not shown).

[0022] Referring to Figs. 1-3, apparatus 30 for installing and/or servicing the wind turbine generator 10 is illustrated. The apparatus 30 includes an inflatable balloon 32 and a plurality of tethering lines 34 for tethering the balloon 32 to ground. To save on weight, but to provide sufficient strength, tethers 34 can be fabricated of synthetic material such as polyamide Kevlar, Spectra, or Dyneema, as examples. The balloon 32 includes a winch 36 mounted thereto for raising and lowering wind turbine generator components for installation or service. Preferably, the winch 36 is movable in a horizontal direction. This ability is useful when making initial installation of a wind turbine generator as well as when servicing components of an existing wind turbine generator. For example, and referring now to Fig. 3, it will be seen that balloon 32 has been inflated with a gas having a density less than atmospheric air so as to elevate the balloon 32 to a position above the nacelle 14. The balloon 32 has a longitudinal extent and a lateral extent, and is positioned above the nacelle 14 so as to be generally centered laterally with the nacelle14. Preferably, the winch 36 is movable in a lateral, horizontal direction. This allows a wind turbine generator component 40 to be raised vertically from the ground to a position above the nacelle 14, to be moved laterally to a position directly above the nacelle 14, and then to be lowered into the nacelle through a hatch or the like. With reference to the drawings in Fig. 1 and 3, in which the wind generator 10 is shown fully assembled, for illustration, it may be noted that the balloon 32 may equally well be operated at a construction site prior to the wind generator assembly or with the wind generator only partially assembled, e.g. not including parts of the rotor, nacelle or tower segments.

[0023] Even more preferable is for the winch 36 to be able to move in a horizontal plane, and not just in a horizontal line. To accomplish this, and referring now to Figs. 4 and 5, a two-axis gantry 50 can be mounted to an underneath side of the balloon 32. The gantry 50 can comprise a pair of longitudinal rails 52, for example I-beams, and a lateral rail 54, for example I-beam, spanning between the longitudinal rails 52. The lateral rail 54 has opposite ends 56 each of which is movably mounted to one of the longitudinal rails 52 as by rollers 58. Similarly, the winch 36 is movably mounted to the lateral rail 54 as by rollers 60 for movement along the lateral rail 34. To save on weight, but to provide sufficient strength, the rails 52, 54 can be fabricated of high-grade aluminium alloy or titanium alloy or carbon fiber material, for example.

[0024] The available travel of winch 36 laterally is preferably enough to allow wind turbine generator components to safely clear the nacelle 14 on one side or the other (or both sides) when being raised or lowered. Similarly, the available travel of winch 36 longitudinally is preferably enough to allow wind turbine generator components to safely clear the nacelle 14 on one end or the other (or both ends) when being raised or lowered.

[0025] In use, and referring to Fig. 2, the balloon 32 is transported to a wind turbine generator site along with tethers 34. The balloon 32 is then inflated with a gas having a density less than atmospheric air to elevate the balloon 32. For example, atmospheric air has a density of about 1.2 kg/m3 and helium has a density of about 0.2 kg/m3, thus creating an upward lift of about 1.0 kg/m3. For typical weights of wind turbine generator components to be lifted, a total upward lift of about 45,000 kg is desired, which requires a static helium balloon containing 45,000 m3. Two tanker trucks 70 each containing 75 m3 of helium at 300 bar pressure can fill a rectangular balloon having a length of 50 m, a width of 40 m, and a height of 22.5 m with 45,000m3 of helium at 1 bar pressure. The balloon 32 is partially inflated to provide enough buoyancy to position the balloon 32 above and centered laterally with the nacelle 14. Next the balloon 32 is tethered from its four corners to ballast on the ground through heave-compensated winches. Then the balloon 32 is fully inflated.

[0026] Referring now to Figs. 1 and 3-5, once fully inflated, the winch 36 can be moved laterally outboard and/or longitudinally outboard of the nacelle 14 and lowered to the ground for connection to a wind turbine generator component 40. Then the winch 36 can be raised to raise the wind turbine generator component 40, and once the wind turbine generator component 40 is above the nacelle 14, the winch 36 can be moved laterally inboard and/or longitudinally inboard so as to position the wind turbine generator component 40 above the nacelle 14. Then the wind turbine generator component 40 can be lowered into the nacelle 14 by the winch 36. Once the installation and/service is complete, the helium is expelled from the balloon 32 and is compressed back into the tankers 70 for use at another location.

[0027] The present invention in its various embodiments provides a number of advantages. There is a significant cost reduction of the “cost of a lift” for all wind turbine generator components compared to large mobile cranes. The apparatus provides for easy mobilization which is especially valuable for remote areas with lacking infrastructure. The apparatus and its use is environmentally conscious in that it vastly reduces C02 emissions by only having to deploy two to four truckloads of equipment versus about fifty truck loads for large mobile cranes. The “cost of a lift” is almost insensitive to hub height (“HH”) thus providing a linear cost level development for component exchange in the future, where average HH is expected to increase significantly. The static balloon of the apparatus is not an air vehicle and thus is not governed by the Federal Aviation Administration (“FAA”), thus avoiding regulatory costs associated with air ships governed by the FAA.

[0028] At bottom, the invention in its various embodiments provides vertical raising and lowering of a suspended load in combination with horizontal displacement of the suspended load. It replaces the role of large construction cranes, while still performing the function of picking components up from ground level at a wind turbine generator construction site and lifting them into position above a foundation, atop a tower, at a nacelle, etc. Moreover, the inflated balloon of the invention can be used at heights which would be prohibitively expensive for a crane.

[0029] The various embodiments of the invention shown and described are merely for illustrative purposes only, as the drawings and the description are not intended to restrict or limit in any way the scope of the claims. Those skilled in the art will appreciate various changes, modifications, and improvements which can be made to the invention without departing from the spirit or scope thereof. The invention in its broader aspects is therefore not limited to the specific details and representative apparatus and methods shown and described. The invention resides in each individual feature described herein, alone, and in all combinations of any and all of those features. Departures may therefore be made from such details without departing from the spirit or scope of the general inventive concept. Accordingly, the scope of the invention shall be limited only by the following claims and their equivalents.

Claims

1. Apparatus for installing and/or servicing a wind turbine generator comprising: a balloon inflated with a gas having a density less than atmospheric air, a plurality of tethering lines attached to said balloon and anchoring said balloon to ground, and a winch movably mounted to said balloon for movement in a horizontal direction.

2. The apparatus of claim 1, wherein said winch is movably mounted to said balloon for movement in a horizontal plane.

3. The apparatus of claim 2, wherein said balloon has a longitudinal extent and a lateral extent, and wherein said winch is movably mounted to said balloon for horizontal movement along the longitudinal extent and the lateral extent.

4. The apparatus of claim 3, wherein said balloon includes a two-axis gantry mounted to an underneath side thereof, said winch mounted to said gantry, said gantry providing horizontal movement of said winch along the longitudinal extent and the lateral extent.

5. The apparatus of claim 4, wherein said gantry comprises: a pair of longitudinal rails, and a lateral rail spanning between said longitudinal rails, said lateral rail having opposite ends each of which is movably mounted to one of said longitudinal rails, wherein said winch is movably mounted to said lateral rail for movement along said lateral rail.

6. The apparatus of claim 5, wherein said lateral rail is movably mounted to said longitudinal rails via rollers, said winch is movably mounted to said lateral rail via rollers, and optionally wherein said tethering lines are fabricated of a material selected from a group consisting of polyamide, Kevlar, Spectra, and Dyneema; preferably wherein said rails are fabricated of carbon fiber material.

7. A method of installing and/or servicing a wind turbine generator comprising: providing an inflatable balloon having a winch movably mounted thereto, tethering the balloon to ground with a plurality of tethering lines, inflating the balloon with a gas having a density less than atmospheric air to elevate the balloon, raising or lowering a first wind turbine generator component with the winch, and moving the winch in the horizontal direction so as to move the first wind turbine generator component in the horizontal direction.

8. The method of claim 7, wherein the step of moving the first wind turbine generator component in the horizontal direction allows the first wind turbine generator component to clear a second wind turbine generator component.

9. The method of claim 7, wherein the winch is movably mounted to the balloon for movement in a horizontal plane.

10. The method of claim 9, wherein the balloon has a longitudinal extent and a lateral extent, and wherein the winch is movably mounted to the balloon for horizontal movement along the longitudinal extent and the lateral extent.

11. The method of claim 10, wherein the balloon includes a two-axis gantry mounted to an underneath side thereof, the winch is mounted to the gantry, the gantry providing horizontal movement of the winch along the longitudinal extent and the lateral extent.

12. The method of claim 11, wherein the gantry comprises: a pair of longitudinal rails, a lateral rail spanning between the longitudinal rails, the lateral rail having opposite ends each of which is movably mounted to one of the longitudinal rails, the winch movably mounted to the lateral rail for movement along the lateral rail.

13. The method of claim 12, wherein the lateral rail is movably mounted to the longitudinal rails via rollers, the winch is movably mounted to the lateral rail via rollers, and the tethering lines are preferably fabricated of a material selected from a group consisting of polyamide, Kevlar, Spectra, and Dyneema, preferably wherein the rails are fabricated of carbon fiber material,.

14. A method of installing and/or servicing a component of an existing wind turbine generator having a tower and a nacelle mounted atop the tower, the method comprising: providing an inflatable balloon having a winch movably mounted thereto, tethering the balloon to ground with a plurality of tethering lines, inflating the balloon with a gas having a density less than atmospheric air to elevate the balloon to a position above the nacelle, raising or lowering the wind turbine generator component with the winch, and moving the winch in the horizontal direction so as to move the wind turbine generator component in the horizontal direction to thereby clear the nacelle.

15. The method of claim 14, wherein the winch is movably mounted to the balloon for movement in a horizontal plane.

16. The method of claim 15, wherein the balloon has a longitudinal extent and a lateral extent, and wherein the winch is movably mounted to the balloon for horizontal movement along the longitudinal extent and the lateral extent.

17. The method of claim 16, wherein the balloon includes a two-axis gantry mounted to an underneath side thereof, the winch is mounted to the gantry, the gantry providing horizontal movement of the winch along the longitudinal extent and the lateral extent.

18. The method of claim 17, wherein the gantry comprises: a pair of longitudinal rails, a lateral rail spanning between the longitudinal rails, the lateral rail having opposite ends each of which is movably mounted to one of the longitudinal rails, the winch movably mounted to the lateral rail for movement along the lateral rail.

19. The method of claim 18, wherein the lateral rail is movably mounted to the longitudinal rails via rollers, the winch is movably mounted to the lateral rail via rollers, and the tethering lines are preferably fabricated of a material selected from a group consisting of polyamide, Kevlar, Spectra, and Dyneema, preferably wherein the rails are fabricated of carbon fiber material.