WO2010147459A2

WO2010147459A2 - A method of finishing a tower section of a wind turbine, a finished tower section of a wind turbine, and a method of transporting a tower section of a wind turbine

Info

Publication number: WO2010147459A2
Application number: PCT/NL2010/000099
Authority: WO
Inventors: Bonne Dijkstra
Original assignee: Xemc Darwind B.V.
Priority date: 2009-06-19
Filing date: 2010-06-18
Publication date: 2010-12-23
Also published as: NL1037052C2; WO2010147459A3

Abstract

The invention relates to a method of finishing a tower section of a wind turbine, such as a bottom tower section. According to the invention, a tower section in an upright orientation is subjected to a finishing operation, wherein at least part of the finishing operation is performed - with the top of the tower section being covered with a cover providing protection from the weather; and - the tower section being in the open. The invention also relates to a wind turbine tower section and to a method of transporting a wind turbine tower section.

Description

A method of finishing a tower section of a wind turbine, a finished tower section of a wind turbine, and a method of transporting a tower section of a wind turbine

The present invention relates to a method of finishing a tower section of a wind turbine.

A tower of a wind turbine comprises one or, usually, more than one tower section. In the latter case, the tower sections are stacked. Tower sections of wind turbines are generally finished at a manufacturing location before being transported to the location where the wind turbine is to be erected. Finishing a tower section generally involves one or more operations in the interior of the tower section, such as installing equipment to operate the wind turbine. A problem is that tower sections can be quite large, and hence occupy a significant amount of precious floor space.

The object of the present invention is to provide a method according to the preamble that reduces the problem.

To this end, the present invention provides a method of finishing a tower section of a wind turbine, wherein a tower section in an upright orientation is subjected to a finishing operation, wherein at least part of the finishing operation is performed

- with the top of the tower section being covered with a cover providing protection from the weather; and

- the tower section being in the open. This protects the interior of the wind turbine section against the weather while avoiding the use of a tall building, which not only needs to accommodate for the height of the tower section in an upright position, but also the work space needed to maneuver above the tower section to introduce equipment or floor elements through the top of the tower section into the tower section. In the present application and as indicated above, the term tower section includes a complete tower. With tall wind turbines, a tower is usually comprised of a stack of at least two tower sections. In general, the tower section to be finished using the method according to the invention will be a bottom tower segment of a wind turbine tower. The cover will be designed to prevent at least part of any precipitation falling on the area occupied by the top of the tower section from ending up in the interior of the tower section, where it could wreak havoc on electri- cal equipment. In general, the cover will be attached to the tower section. Tower sections generally have a flange at their top end for attaching a tower section or nacelle on top of the tower section. This flange provides excellent opportunity to attach the cover. After the last element to be introduced via the top of the tower section has been introduced and the top of the tower section has been moved on top of the tower section, the cover may be permanently attached to the top of the tower section to become part of it. This may be of use in case a floor is used as the cover. However, in general the cover is a removable cover, that is preferably removably attached to the top of the tower section, as this allows introduction of any large element at a desired point in time during the finishing of the tower section. The removable cover may be used for finishing multiple tower sections. While a cover may be a floor, it is not a nacelle. Also, it is preferred that the cover is inclined downward towards the perimeter of the top of the tower section, so as to allow rain water to run off the cover. It is conceivable that rain collected on the cover is drained via a tube, which may run inside the tower section, but it is not preferred as it involves more work and adds expense. The term "in the open" means without a roof above the tower section. The term "finishing" operation means an operation that is performed within the tower section and can at least partly be performed with the cover on top of the tower section. To introduce an element into the tower section, the cover may be removed, rotated, shifted or oth- erwise moved to provide an opening at the top of the tower section sufficiently large to introduce the element. In the present application, in association with "cover" the term "removed" means that the top is opened sufficiently for the element to be introduced via the top of the tower section, but in practice the top will be completely removed. This will generally be done with a crane, which is also used to introduce the element into the tower section.

JP2004156478 discloses a method of performing work on a wind turbine, such as maintenance, inspection and coating of a wind turbine tower. Use is made of a mobile scaffold comprising a frame that is placed on top of the wind turbine tower and anchored to the ground. The frame is not a cover; it does not protect the interior of the tower against the weather. According to a preferred embodiment, the tower section is brought from a non-vertical orientation to an upright orientation after which the tower section is subjected to the finishing operation.

This allows the tower section to be manufactured in a substan- tial horizontal orientation, as can be done in a manufacturing hall, allowing construction workers such as welders to work in a protected environment, before performing one or more finishing operations with the tower section being in an upright orientation outside.

According to a favourable embodiment, the cover is placed onto the tower section while the tower section is in the upright orientation before performing at least part of the finishing operation.

The cover may be placed on top of the tower section with the same equipment - usually a crane - as used to put the tower section in an upright position and/or as used to hoist any equipment or con- struction element into the interior of the tower section.

According to a favourable embodiment, the cover is a removable cover and is temporarily removed, an element to be installed is introduced via the top of the tower section, following which the cover is used to cover the tower section again. This allows the element, such as equipment or a construction element such as a floor or part thereof, to be introduced into the interior of the tower section at an appropriate time, generally during precipitation-free weather.

According to a highly preferred embodiment, the cover is a light-transmitting cover.

It may for example be constructed using glass or transparent plastic such as polycarbonate. The light-transmitting material will usually be in the form of panes. Such a light-transmitting cover improves working conditions, even over those in a factory hall and/or may save electrical energy for lighting while performing the finishing operation.

The method according to the invention allows a large variety of finishing operations to be performed, and preferably the finishing operation is at least one operation chosen from the group consisting of providing i) a floor element, ii) a stair, iii) a transformer, iv) a cooling unit, v) a cable, vi) a control cabinet, vii) an uninterruptible power supply (UPS) , viii) switch gear, ix) a converter, and x) painting. Switch gear is gear used to connect and disconnect a turbine from a mains cable.

According to a highly preferred embodiment the finishing operation involves providing a unit comprising at least 2 elements chosen from the group consisting of i) a floor element, ii) a stair, iii) a transformer, iv) a cooling unit, v) a cable, vi) a control cabinet, vii) an uninterruptible power supply (UPS) viii) switch gear, and ix) a converter.

This reduces the number of times the cover has to be temporar- ily removed.

According to a preferred embodiment, the cover is capable of collecting at least 50%, preferably at least 80%, more preferably at least 95% and most preferably 100% of rain falling on the top of the tower section. The percentages are for rain falling within the top perimeter of the tower section at a given moment. When it comes to protection of electrical equipment, it goes without saying that while some leakage along the inner wall of a wind turbine might be allowable, a cover will form a complete barrier to eliminate any risk because of rain water.

The present invention also relates to a wind turbine tower section in an upright orientation with the top of the tower section being provided with a cover.

This wind turbine tower section can be manufactured with the method according to the invention.

According to a preferred embodiment, the cover is a removably attached cover.

The cover can be optimally adapted for the purpose as cover, instead of having to satisfy further requirements concerning its presence in a finished wind turbine if it were also to serve as a floor.

According to a preferred embodiment, the cover may be provided with a lightning rod so as to protect the workers and/or equipment in the interior of the wind turbine section. Finally, the invention relates to a method of transporting a wind turbine tower section, wherein the wind turbine tower section according to the invention is transported in an upright orientation. Thus the tower section and its contents can be safely transported, protected from the weather.

The present invention will now be illustrated with reference to the drawing where fig. 1 depicts a side view of a crane and tower section (cut away to show its interior) provided with a cover; fig. 2 represents a top view of the cover of fig. 1; fig. 3 represents a cross-sectional view of a part of fig. 1 (circle) ; and fig. 4 shows a cross-sectional detail of fig. 2.

Fig. 1 shows a bottom tower section 100 for a wind turbine in a side view and in an upright position, the bottom tower section 100 comprising tower section wall 101. Inside, the bottom tower section

100 is provided with floors 102, 103. The floors 102, 103 are pro- vided with equipment, in particular a transformer 104, a converter

105, and unit 106 comprising a control cabinet, a UPS and a switch gear (not separately visible) . The bottom tower section 100 is out in the open, that is, not in a factory hall. Generally, it will be placed on a row of substantially parallel I-beams and depending on the soil, no foundation is necessary.

The bottom tower section 100 is provided with a cover 110, which comprises a frame 111 provided with transparent panes 112, as will be explained in more detail with reference to fig. 2 and 3.

Next to the tower section 100 is a crane C. It has been used to hoist the floors 102 and 103, transformer 104, a converter 105, and unit 106 into the bottom tower section 100 and to place the cover 110 on top of the upright bottom tower section 100. To this end, the cover 110 has an eye 114 that can be grappled by hook H of the crane C. The eye 114 may be a removable or hingedly attached eye 114 to al- low easy stacking of multiple covers 110. A hingedly attached eye 114 would be able to rotate an axis of rotation parallel to the plane of the eye, and capable of lying against the topside of the cover. 110. Alternatively, the eye 114 may be capable of sinking into the cover, such that the top of the eye 114 protrudes to an insignificant extent or not protrude at all above the top side of the cover 110. According to a favourable embodiment, it may be locked in the high position be^¬ fore use . Fig. 2 shows the cover 110 in a top view, with an octagonal frame 111 provided with the eye 114 for moving the cover 110 and panes 112 that allow daylight to enter the interior of the bottom tower section 100. The cover 110 covers the whole top of the bottom tower section 100, effectively forming a barrier to rain or other precipitation from entering the interior to an undesirable extent.

The bottom tower section 100 has a flange 301, which upon erection of the wind turbine will be used to attach the next tower section that will be placed on top of the bottom tower section 100. This is done using bolts. The presence of this flange 301 is taken advantage of to temporarily attach the cover 110 as shown in fig. 3, which shows part of fig. 1 in detail. Frame 111 is attached to the flange 301 using bolts 302 and nuts 303, ensuring that it cannot be lifted from the bottom tower section 100 in case of adverse weather condi- tions such as a storm. If the cover 110 is to be temporarily removed to introduce equipment into the bottom tower section 100, the bolts are removed and the cover 110 is lifted using crane C and placed next to the bottom tower section 100. Usually, only a few bolts 302 will suffice to reliably fix the cover to the bottom tower section 100 and it is not much work to remove them.

The bottom tower section 100 is subjected to one or more finishing operations, such as installing cables and connecting the equipment placed into the bottom tower section 100.

The bottom tower section 100 will be transported to its final destination in the upright position. If desired, a different cover may be used for that, for example a more simple non-transparent cover, leaving the more expensive cover available at the work site for performing finishing operations on another tower section.

Fig. 4 shows a cross-sectional view through a spar 111' of frame 111. The spar 111' carries polycarbonate panes 112, 112' . A cover fillet 113 holds the panes 112, 112' in place, and is bolted to the spare 111' with screw 114. To accommodate for differences in expansion coefficients between frame 111 and the panes 112, 112' and to prevent water such as rain water from passing the cover, strips of rubber 115 are provided.

Claims

C L A I M S

1. A method of finishing a tower section (100) of a wind turbine, wherein a tower section (100) in an upright orientation is subjected to a finishing operation, wherein at least part of the finishing operation is performed

- with the top of the tower section (100) being covered with a cover (110) providing protection from the weather; and - the tower section (100) being in the open.

2. The method according to claim 1, wherein the tower section (100) is brought from a non-vertical orientation to an upright orientation after which the tower section (100) is subjected to the finishing op- eration.

3. The method according to claim 1 or 2, wherein the cover (110) is placed onto the tower section (100) while the tower section (100) is in the upright orientation before performing at least part of the finishing operation.

4. The method according to claim 3, wherein the cover (110) is a removable cover and is temporarily removed, an element (104, 105, 106) to be installed is introduced via the top of the tower section (100), following which the cover (110) is used to cover the tower section (100) again.

5. The method according to any of the preceding claims, wherein the cover (110) is a light-transmitting cover.

6. The method according to any of the preceding claims, wherein the finishing operation involves at least one operation chosen from the group consisting of providing i) a floor element (102, 103), ii) a stair, iii) a transformer (104), iv) a cooling unit, v) a cable, vi) a control cabinet, vii) an uninterruptible power supply (UPS), viii) switch gear, ix) a converter (105), and x) painting.

7. The method according to any of the preceding claims, wherein the finishing operation involves providing a unit (106) comprising at least 2 elements chosen from the group consisting of i) a floor element, ii) a stair, iii) a transformer (104), iv) a cooling unit, v) a cable, vi) a control cabinet, vii) an uninterruptible power supply (UPS), viii) switch gear, and ix) a converter (105) .

8. The method according to any of the preceding claims, wherein the cover is capable of collecting at least 50%, preferably at least 80%, more preferably at least 95% and most preferably 100% of rain falling on the top of the tower section (100) .

9. A wind turbine tower section (100) in an upright orientation with the top of the tower section (100) being provided with a cover (110) .

10. The wind turbine tower section (100) according to claim 9, wherein the cover (110) is a removably attached cover.

11. The wind turbine according to claim 9 or 10, wherein the cover is provided with a lightning rod.

12. A method of transporting a wind turbine tower section (100), wherein the wind turbine tower section (100) of claim 8 or 9 is transported in an upright orientation.