Patent Application
20220381227
Aspects of the invention relate to techniques, apparatus and methods for covering openings in wind turbine structures, particularly but not exclusively for the purposes of weatherproofing.
Wind turbines are sealed structures so as to protect their interiors from the external environment. Although wind turbines will have various doors and hatchways so that maintenance crew can enter, in general the rest of the wind turbine will not be open to the external environment during operation. During construction and installation, however, it may be the case that internal sections and compartments of the wind turbine need to be left exposed to the environment. For example, the wind turbine tower may be erected before other components such as the hub, nacelle and blades arrive at the installation site. In this situation therefore, the top of the tower may be left exposed for a long period of time until the nacelle is installed. Similarly, for transport purposes the hub is typically carried without its blades attached. The apertures in the hub which would ordinarily support the blades may therefore be open to the environment.
The conventional way of dealing with this problem is to apply fabric covers or closures to any openings of the wind turbine structure which need to be covered up to protect the interior of the structure from the potential harsh external environment. Although generally considered to be adequate, the conventional fabric covers have their limitations: for instance, that they can be problematic to tie down over an opening; their flexibility can result in flapping during high wind that can promote the ingress of water, particularly as spray, they generally require a respective frame if they are to provide a ‘peaked’ cover of some sort, which increases weight and complexity. Accordingly, an improved solution is sought for protecting the openings in wind turbine structures.
According to a first aspect of the embodiments of the invention, there is provided a wind turbine structure comprising: a surface defining at least in part an opening, and a closure system provided adjacent the opening, the closure system including an inflatable closure that is inflatable into a deployed state in which the inflatable closure engages the surface so as to cover at least a portion of the opening.
In this way, the invention advantageously allows for a portion of the wind turbine structure to be protected from the external environment. For example, when inflated the inflatable closure may protect the structure from ingress of water, snow, ice and/or other contaminants. The wind turbine structure to be protected may be in the form of, for example but not limited to, a tower or tower segment or section, a foundation, a hub, or a blade.
In some embodiments, the closure system may be provided within, and/or be attached to, the wind turbine structure.
The inflatable closure may define an edge profile that is configured to match a complementary engaging profile defined by the surface of the opening.
The inflatable closure may define a substantially planar body in the deployed state. The inflatable closure in the deployed state may define a plurality of ribs interconnected by webs. Incorporating ribs on the inflatable closure enhances the structural rigidity of the closure, and may be especially beneficial when the closure is to be used across large openings, to help prevent sagging.
The closure system may include a housing which is configured to contain the inflatable enclosure in a stowed state.
The closure system may comprise a rigid plate that covers at least a portion of the opening.
The inflatable closure may be housed at least partially within the rigid plate in the stowed state. The rigid plate may be foldable, which may be advantageous, for example, during transport of the closure system, allowing a dimension of the closure system to be reduced if required or helpful.
The closure system may include an inflation pump to inflate the inflatable enclosure. The inflation pump may be operable to deflate the inflatable enclosure.
The inflatable closure may be mounted on an edge of the opening.
The inflatable closure may engage the surface to form a water-tight seal. In some embodiments, the water-tight seal may be realised using a rubber or silicone member provided between the inflatable closure and the surface of the opening that the closure engages when inflated. A water-tight seal may be particularly important in offshore environments to prevent salt sprays or salt containing aerosols, which may be very corrosive, from entering the structure.
The inflatable closure may comprise multiple air-tight internal chambers that can be individually inflated and deflated. Including multiple air-tight chambers that can be controlled separately to inflate and/or deflate individually provides the system with an enhanced level of flexibility. For example, this functionality may be useful in a situation in which a portion of the opening of the wind turbine structure must be accessible, but it would be beneficial for the remainder to be covered and protected.
The closure system may comprise multiple inflatable closures. In this way, multiple openings or portions of the opening may be covered separately, again adding flexibility to the system. Furthermore, a very large opening, or an opening with a complicated shape, may be fully covered more easily.
The inflatable closure may comprise a base layer of drop-stitch material.
According to another aspect of the invention, there is provided a method of at least partially covering an opening of a wind turbine structure, the method comprising; providing a closure system including an inflatable closure adjacent the opening; and inflating the inflatable closure from a stowed state to a deployed state in which the inflatable closure covers at least a portion of the opening.
The method may comprise engaging the inflatable closure with a surface that defines, at least in part, the opening.
Engaging the inflatable closure with the surface may comprise engaging an edge profile of the inflatable closure with a complementary engaging profile defined by the surface of the opening.
The method may comprise inflating the inflatable closure from a housing in which it is contained in the stowed state.
The method may comprise inflating the inflatable closure from a housing that forms part of a rigid plate that covers at least a portion of the opening.
The method may comprise deflating the inflatable closure so as to provide access to a portion of the opening.
The method may comprise inflating and/or deflating multiple air-tight internal chambers of the inflatable closure individually. The method may comprise inflating and/or deflating at least one of the internal chambers before at least one other of the internal chambers.
The method may comprise remotely activating inflation and/or deflation of the inflatable closure. Activating inflation and/or deflation of the closure or closures remotely removes the need for personnel to travel to the site and do so manually, thus saving time and resources.
Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.
The invention will now be described by way of example with reference to the accompanying drawings, in which:
The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice the invention. Other embodiments may be utilised, and structural changes may be made without departing from the scope of the invention as defined in the appended claims.
Examples of wind turbine structures 10 are towers or tower sections, foundations, transition pieces, blades, hubs, nacelles, and wind turbine structure support which may, for example, be provided at a preassembly site or on a vessel.
The wind turbine structure 10 comprises a closure system 20 that is configured to at least partially cover an opening 22 of the wind turbine structure 10 when deployed, so as to protect the interior of the wind turbine structure 10 from the external environment.
In this embodiment, the opening 22 of the wind turbine structure 10 to be covered is defined at an upper end 24 of a tower segment 15 of the wind turbine 8, to which another tower segment 15, or the nacelle 12, may be attached when the turbine 8 is assembled.
The upper end 24 of the tower segment 15 comprises a circumferential flange 28 to which a further tower segment 15, or the nacelle 12, is bolted when the wind turbine 8 is assembled. The circumferential flange 28 extends radially inwardly from the outer surface 26 of the tower segment 15 to an inner surface 30 of the flange 28, and comprises a plurality of fastener-receiving openings or ‘bolt holes’ 32. The inner surface 30 of the flange 28 defines the opening 22 of the tower segment 15 to be covered. The opening 22 leads to an internal volume or chamber 34 of the tower segment 15, which defines a generally cylindrical volume within the tower segment 15.
The closure system 20 is located within the internal chamber 34 of the wind turbine structure 10, and is positioned adjacent the opening 22. As can be seen in
The closure system 20 comprises an inflatable closure 36 that can be deployed from a stowed state illustrated in
Referring to
As best illustrated in
The inflatable closure 36 comprises upper and lower surfaces, 48 and 50 respectively, that are generally circular in shape, and a circumferential surface 52 that joins the upper and lower surfaces, 48 and 50 respectively, at their edges. The upper surface 48 faces away from the internal chamber 34 when the inflatable closure 36 is deployed, and the lower surface 50 faces towards the internal chamber 34 when deployed.
The inflatable closure 36 of this embodiment is formed by a base layer (not shown) and an outer layer 54.
The base layer preferably comprises a layer of drop-stitch material/fabric, which is a known technology, for example at www.duletai.com. The drop-stitch material will not be described in detail here but, briefly, is formed by two support layers of polyester woven fabric joined by polyester threads that extend between them.
The outer layer 54 comprises an air tight coating that surrounds and encloses the base layer, and that defines an internal volume or chamber (not shown) that is filled with air when the closure is inflated. In this embodiment, the outer layer 54 includes two elongate ridges or ribs 56 that extend across the upper surface 48 of the closure 36, to enhance its structural rigidity in the deployed state.
The inflatable closure 36 further comprises a valve (not shown) through which the closure is inflated and deflated in use. To inflate and deflate the closure 36, an inflation pump (not shown) is attached to the valve, and the internal volume is filled with or emptied of air using the pump. In other embodiments, the closure 36 may be inflated using an inflator unit that forms a part of the closure system 20. The inflator unit may be integrated within the internal volume of the inflatable closure 36. Examples of suitable inflator units could be electrical blowers, which may be battery powered, canisters of compressed gas e.g. air, or inflators that are based on chemical reactions to generate gas to inflate the closure 36, or on physical reactions (i.e. evaporation or sublimation) to generate gas to inflate the closure 36. If the closure system 20 comprises a housing 38, then it is preferred that the inflator unit is integral with the housing or is integrated in the inflatable closure 36.
The valve may be provided at any position on the inflatable closure 36. In some embodiments, the valve is provided so as to be accessible to a user without removing the inflatable closure 36 from the housing 38. In this way, the inflation pump can be attached to the valve without first removing the inflatable closure 36 from the housing 38. In other embodiments, the valve may be positioned such that the inflatable closure 36 must be removed from the housing 38 before the inflation pump can be attached. In some embodiments, in particular those in which the closure 36 fully covers the opening 22 in the deployed state, the valve is preferably positioned on the upper surface 48 of the closure 36, so as to be accessible even when the closure 36 is fully deployed and secured in place. In some embodiments, in particular those in which the inflatable closure 36 forms a roof over the internal chamber 34 of the structure 10 when deployed, the valve is preferably positioned to face the internal chamber 34. In some embodiments, in particular those where the upper and lower surfaces 48, 50 of the inflatable closure 36 are both accessible after deployment, multiple valves may be arranged on the inflatable closure 36. In particular, at least one valve may be provided on the upper surface 48 of the closure 36 and at least one valve may be provided on the lower surface 50 of the closure 36.
In one embodiment, the valve and/or the inflator unit is remotely operable. This is particularly advantageous where the closure 36 covers an opening 22 that may be used for access of tools to handle, for example to lift, the wind turbine structure 10. The ability to remotely operate the valve and/or the inflator unit removes the need for personnel to travel to the structure 10 to inflate and/or deflate the closure 36, thus saving considerable time and resources. Furthermore, the ability to remotely operate the valve and/or the inflator unit may improve site safety. For example, in a scenario in which a tower section 15 is being lifted on site, it is preferable that personnel are not in the vicinity, because it is unsafe for personnel to be working near or under suspended loads. Remote operation of the valve and/or inflator unit allows an operator to inflate and/or deflate the closure 36 without having to enter the site. In this case, it is preferred that one or more sensors are arranged in the vicinity of the structure 10 so as to provide confirmation that the closure 36 has been properly inflated/deflated/positioned before engagement of, for example, a tool for lifting the structure 10. The one or more sensors may be any suitable sensors, including but not limited to cameras for capturing images and/or video footage, and/or contact/proximity sensors.
Turning now to
The circumferential surface 52 of the inflatable closure 36 defines an edge profile 58 that includes a flange-receiving aperture 60 defined between upper and lower edge portions, 62 and 64 respectively, of the inflatable closure 36, and configured to receive the flange 28 of the tower segment 15 when deployed. In this way, the flange 28 defines an engaging profile 66 that is complementary to the edge profile 58 of the inflatable closure 36. In this embodiment, the flange receiving aperture 60 forms a circumferential groove that extends around the edge of the inflatable closure 36 and that corresponds to the flange 28 that forms a circumferential edge that extends around the upper end 24 of the tower segment 15.
The upper and lower edge portions, 62 and 64 respectively, each include a plurality of fastener-receiving openings 68. Openings 70 of the lower edge portion 64 define generally circular through-holes that extend from the lower surface 50 of the closure 36, to an upper surface 72 of the lower edge portion 64 that faces the flange 28 when the closure 36 is deployed. Openings 74 of the upper edge portion 62 define generally circular holes in a lower surface 76 of the upper edge portion 62 that faces the flange 28 when the inflatable closure 36 is deployed. Each opening 68 comprises a threaded metal coating or insert 78 on its interior surface 80 for engagement with a bolt 82. It should be appreciated that the use of such fastener receiving openings and corresponding bolts is not required, but is an additional safety feature that may ensure maintained connection between the closure 36 and the structure 10, even in the unlikely event that the closure 36 should lose pressure or be torn from the opening 22 by weather, for example.
When the closure 36 is inflated and properly positioned for use, the flange 28 of the tower segment 15 is received in the flange-receiving aperture 60 of the closure 36, and the fastener-receiving openings 68 of the upper and lower edge portions 62, 64 align with the fastener-receiving openings 32 of the flange 28. Thus, complementary profiles of the closure 36 and the flange 28 are engaged, and the inflatable closure 36 is mounted on an edge 84 of the opening 22.
In this embodiment, the upper edge portion 62 terminates so as to be flush with the outer surface 26 of the tower segment 15. To secure the inflatable closure 36 to the tower segment 15, fasteners such as bolts 82 or screws extend through one or more of the aligned sets of fastener-receiving openings 68, 32 of the upper and lower edge portions 62, 64 of the closure 36 and the flange 28.
The inflatable closure 36 may be deployed during transport of the tower segment 15 to an installation site at which the wind turbine 8 is to be assembled, and up until installation, so as to protect the tower segment 15, and in particular the internal chamber 34 of the tower segment 15, from the external environment. For example, the closure 36 may protect the internal chamber 34 from ingress of water, snow, ice and/or other contaminants. Thus, although
When the wind turbine 8 is ready to be installed, the inflatable closure 36 can simply be deflated via a release valve or using the inflation pump to release air from its interior, and removed from the tower segment 15 along with the housing 38 in which it can be re-packed ready for future use. It is envisaged that suitable fold lines can be introduced to the inflatable enclosure during manufacturing to ensure that the inflatable enclosure can re-configured itself into a stowed state inside the housing 38 when air is pumped out.
In
Turning now to
In this embodiment, the closure system 20 comprises three inflatable closures 36 which together cover the opening 22 of the tower segment 15 when deployed. As illustrated, the different inflatable enclosures 36 engage with one another when in the inflated state so as to span the gap across the opening 22. Usefully, the different enclosures can contribute different functionality to the overall coverage of the opening 22. For example and as will be described further below, the middle enclosure 90 is formed into generally an I-beam shape so as to provide increased strength and rigidity to the overall closure structure. This may be useful where high loads are expected to be supported by the closure 36, for example after heavy snow fall.
Specifically, the closure system 20 comprises a central closure 90 and two outer closures 92. Each inflatable closure 36 is formed from a base layer and an air-tight outer layer 54, and includes a valve (not shown) for inflation and deflation, as in previous embodiments. In other embodiments one or more of the closures 36 may comprise an airtight inner layer and a protective or structural outer layer.
The central inflatable closure 90 preferably comprises a flat rectangular lower surface 94 and a curved upper surface 96 that generally defines a segment of a cylinder, as is best seen in
This may be illustrated using the embodiment shown in
It should be understood that the inflatable closure 36 may take another shape than generally flat. For example, the inflatable closure 36 may take the shape of a dome or pyramid having, for example, 3, 4, 6, 8 or more faces. A non-flat shape has been found to be particularly advantageous for closures 36 acting as a generally horizontal cover of a wind turbine structure 10, as this tends to aid in the removal of rain, snow, dust or other debris from the closure 36, and hence prevents or reduces the risk of build-up of large weights of debris that potentially may damage the closure 36. Non-flat structures may, for example, be realised through the use of ribs, which may or may not be inflatable, and which are integrated with the inflatable closure 36. Alternatively or additionally, non-flat structures may be realised through the use of separate support elements arranged vertically under the closure 36 to support the closure 36.
The outer inflatable closures 92 are identical to each other, and each comprises an upper surface 112 and a lower surface 114. The upper and lower surfaces 112, 114 are joined by an outer side surface 116 that engages with the flange 28 of the tower segment 15 when deployed, and an inner side surface 118 that engages with the central closure 90 when deployed. The outer side surface 116 may for example have an identical profile to the circumferential surface 52 of the embodiment of
When deployed, the protrusions 120 of the outer closures 92 are received in the closure-receiving openings 108 of the central closure 90, and the flange 28 of the tower segment 15 is received in the flange-receiving openings 60 of the central and outer closures 90, 92. The central closure 90 extends across the diameter of the opening 22, and covers a central portion 122 of the opening 22. The outer closures 92 are positioned on either side of the central inflatable closure 90, and cover the rest of the opening 22.
In this way, the inflatable closures 90, 92 together form a covering that fully covers the opening 22 of the tower segment 15 when deployed. In other embodiments, one or more of the inflatable closures 90, 92 may be omitted, or the dimensions of the closures 90, 92 may differ, such that the inflated closures 90, 92 only partially cover the opening 22 of the tower segment 15 when deployed. This also allows deflation of part of the full closure system 20 to allow access to the inside of the wind turbine structure 10 without complete removal of the closure system 20. For example, to enable access to personnel, or for equipment or tools for lifting the wind turbine structure 10.
The frame 124 is generally square-shaped, and comprises a base 126 and first and second flanges 128, 130. Other shapes of the frame 124 such as circular or polyhedral are similarly feasible when the shape of the inflatable closure 36 is shaped accordingly. The first and second flanges 128, 130 extend inwardly towards the centre of the frame 124, from first and second edges 132, 134 of the base 126, and are generally perpendicular to the base 126. In this way, the frame 124 has a U-shaped profile in cross-section, and defines a rectangular aperture 136 in which edges 138 of the inflatable closure 36 are received in the deployed state.
The inflatable closure 36 of this embodiment is generally square when inflated, as shown in
To deploy the inflatable closure 36, an inflation pump is connected to the valve 140, and air is pumped into the closure 36. The closure 36 inflates from an uninflated state shown in
The plate 146 is rigid and has first and second ends, 148 and 150 respectively, joined by first and second sides, 152 and 154 respectively. The plate 146 comprises an upper generally planar surface 156 and a lower generally planar surface (not shown), which are joined by a peripheral surface 160. The upper surface 156 includes a plurality of ridges or ribs 162 that extend across the plate 146, from the first end 148 to the second end 150, and that are connected by webs 164. The ribs 162 act to enhance the structural rigidity of the plate 146. The plate 146 of this embodiment further includes four hinges 166 at which the plate 146 can fold. The hinges 166 allow the width of the plate 146 to be reduced, which may be advantageous, for example, during transport of the closure system 20, and when not in use.
The plate 146 is dimensioned in this example to cover a central portion 168 of the opening 22, and to define first and second openings, 170 and 172 respectively, between the plate 146 and the flange 28 of the tower segment 15, when installed on the tower segment 15. In this way, the internal chamber 36 of the tower segment 15 can still be accessed via the first and second openings, 170, 172, even when the plate 146 is installed on the tower segment 15, and the closure system 20 is ready to be fully deployed.
When installed at the tower segment 15, the plate 146 extends across the diameter of the opening 22. As best seen in
Referring now to
When in the stowed state, the inflatable closure 36 is stored at least partially within the plate 146, in a housing cavity (not shown) defined between the upper surface 156 and the lower surface (not shown) of the plate 146. In other embodiments, the inflatable closure 36 may be contained within a separate housing attached to the plate 146.
To deploy the inflatable closure 36, the closure 36 is partially removed from the housing cavity and the valve is located. An inflation pump is attached to the valve, and the closure 36 is inflated. When deployed, the inflatable closure 36 covers the first opening 170, and is supported from below by the flange 28 of the tower segment 15. An edge region (not shown) of the closure 36 that engages with the plate 146 when inflated is received in an aperture (not shown) that extends across the first side 152 of the plate 146, and in the housing cavity, and engages with the plate 146 in a similar manner to that shown in
Although the closure system 36 of this embodiment includes only a single inflatable closure 36, other embodiments may include additional inflatable closures 36, attached at different positions of the plate 146. For example, a second inflatable closure may be attached at a corresponding position at the second side 154 of the plate 146, so as to cover the second opening 172 when deployed. In another variant, multiple inflatable closures 36 may be installed at one side of the plate 146, and be configured to together fully or partially cover the corresponding opening when deployed.
Many variations and modifications to the above-described arrangements are possible within the scope of the invention.
For example, the wind turbine structure 10 may include additional supports 176, as shown in
Although the embodiments described in the preceding paragraph each include a base layer and an outer layer 54, in other embodiments the closure 36 may only include an air-tight outer layer 54, and not include a base layer. Alternatively, the closure 36 may include an airtight inner layer and a protective or structural outer layer.
Closures 36 of the invention are also not limited to including only one valve and one internal chamber 34. Closures 36 of other embodiments of the invention may include multiple valves associated with one internal volume. Closures 36 of other embodiments may further define multiple air-tight chambers, which can be inflated and deflated separately, and preferably sequentially, by means of one or more associated valves.
It is to be understood that many different methods may be used to secure a closure 36 of the invention to a wind turbine structure 10. For example, the closure 36 may be secured in place simply by means of friction between the closure 36 and a surface of the wind turbine structure 10, or may be secured via friction and fastening means. Fastening means may include bolts, screws, and wires, that may extend through fastener-receiving openings of the closure and the wind turbine structure 10. Furthermore, the use of magnets may be employed, especially in embodiments in which the wind turbine structure 10 does not include fastener receiving openings in the vicinity of the closure system 20. In this case, a magnetic element may be attached to the wind turbine structure 10, and a wire may extend from the magnet to a connection point of the closure 36, thereby securing the closure 36 to the structure 10. Alternatively, the magnet may be directly integrated into the inflatable closure 36 and/or attached to the surface of the closure 36.
Many different shapes and sizes of the closure 36 are possible within the scope of the invention, as well as many different profiles of the closure 36 for engaging with the wind turbine structure 10. For example, the edge profiles 58 of the closures 36 shown in
Finally, it will be understood that although the invention has been described in the context of a tower segment 15, a closure system 20 of the invention could be incorporated at any location at which an opening 22 is to be covered. In other embodiments, the closure system 20 may protect other portions of the wind turbine 8. For example, the closure system 20 could protect blade-receiving apertures of the hub, before the blades 28 have been attached, or could protect hatches or doorways of the wind turbine 8 as well as foundations, transition pieces, blades, nacelles, and wind turbine stands at a preassembly site or a vessel.
| Number | Date | Country | Kind |
|---|---|---|---|
| 19211508.7 | Nov 2019 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DK2020/050307 | 11/12/2020 | WO |
