US20120023860A1

US20120023860A1 - Adapter Configuration for a Wind Tower Lattice Structure

Info

Publication number: US20120023860A1
Application number: US13/115,558
Authority: US
Inventors: Stefan Voss
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2011-05-25
Filing date: 2011-05-25
Publication date: 2012-02-02

Abstract

A wind turbine tower includes a lattice tower structure having a plurality of vertically oriented columns and cross-brace members. An adapter is molded onto a top of the lattice tower structure such that top portions of the columns are embedded into the adapter. The adapter may be a concrete member molded onto the lattice tower structure.

Description

FIELD OF THE INVENTION

The present invention relates generally to wind turbine tower structures, and more particularly to an adapter configuration that may utilized between the lattice tower and an upper tubular component of the wind turbine, or at the interface between a jacket foundation and tower for offshore wind turbines.

BACKGROUND OF THE INVENTION

Conventional wind turbine towers typically include a tubularpole construction to support a wind turbine at a considerable height to capture wind energy. The tubular tower configuration is relatively simple and easier to assemble, but utilizes a considerable amount of material, particularly steel. With the rising costs of these materials, the tubular towers become economically disadvantageous for certain hub heights and geographic regions.
The growing acceptance of wind energy as a significant alternative energy source depends on large part in maintaining the cost-per-kilowatt of power produced at an acceptable level. In this regard, lattice tower structures are gaining acceptance as a cost-effective alternative to the conventional tubular towers due, primarily, to significantly reduced amount of steel used in the lattice towers.
With certain conventional configurations, the wind tower structure includes a lower lattice tower section and an upper tubular section, with the machine head mounted atop the tubular section. A steel adapter is provided at the interface between the lattice tower section and the tubular section. In another known configurations, the machine head is supported directly atop of the lattice tower section, also with an adapter provided between the lattice tower section and the machine head. An example of this configuration is the “Space Frame Tower™” from Wind Tower Systems of Park City, Utah, USA, wherein a steel interface flange is welded to the top of the lattice tower. The yaw bearing ring in the machine head is bolted directly to this interface flange.
The interface between the lattice tower structure and the machine head or a tubular component that supports the machine head is crucial. The load transfer issues from the machine head to the vertical legs of the lattice tower can be quite complex. It is the conventional practice to use a welded steel adapter at this interface, as with the configurations discussed above. This steel adapter is, however, expensive to produce and requires skilled technicians (including welders) to configure the adapter to the tower, all of which adds to the overall cost of the wind turbine.
The concerns are similar with respect to offshore wind tower structures wherein the towers are connected to lattice or girder structures anchored to the sea bed with complex welded steel adapter structures.
Accordingly, an improved adapter configuration between the lattice tower structure and the machine head structure that is cost-effective and possesses superior load transfer capabilities is desirable.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In accordance with aspects of the invention, a wind turbine tower construction is provided having a lattice structure with a plurality of vertically oriented columns and cross-brace members. An adapter is molded onto a top of the lattice structure such that top portions of the columns are embedded into the adapter. The wind turbine tower structure may be land-based on an off-shore installation.
The adapter is configured for connection with structure that supports the machine head (“nacelle”) of the wind turbine, such as a tubular tower component on which the machine head is mounted or a component within the machine head. In this regard, the adapter may in one embodiment include a plurality of anchor bolts embedded therein for receipt of the tubular component. In another embodiment, a plurality of bolt holes may be defined through the adapter for receipt of respective bolts used to attach any manner of structure to the adapter. In still a further alternative embodiment, a plurality of threaded inserts may be provided in the adapter for receipt of a machine head component or other supporting structure.
The adapter is not limited to a particular moldable material, and may be formed of any suitable settable, hardened material formed onto and around the top portions of the columns. In a particular embodiment, the adapter is a concrete member poured and formed onto the top portions of the columns. In this concrete embodiment, any configuration of anchor members may be attached to the top portions of the columns and embedded in the concrete member. If anchor bolts are used in this embodiment, such bolts may be pre-tensioned in the concrete adapter.
The shape, dimensions, appearance, and the like, of the adapter are not limiting factors of the invention. In a particular embodiment, the adapter is formed as a cylindrical plate-like member.
In a unique embodiment, the lattice structure includes a plurality of vertically aligned and connected sections that may be erected at the wind turbine site. A top one of the sections may have the adapter pre-molded onto the columns.
It should be appreciated that the invention also encompasses a section of a wind turbine tower, wherein the section includes a plurality of vertically oriented columns and cross-brace members interconnected to define an open lattice structure, and with an adapter molded onto a top of the columns such that top portions of the columns are embedded into the adapter. The adapter may be configured in various different embodiments as discussed above.
The present invention also encompasses any manner of a wind turbine that incorporates a lattice structure with an adapter as set forth herein.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 is a perspective view of a wind turbine with a lattice tower structure that may incorporate an adapter configuration in accordance with aspects of the invention;

FIG. 2 is a perspective view of an alternative embodiment of a wind turbine with a lattice tower structure and adapter configuration;

FIG. 3 is a side cut-away view of a top portion of a lattice tower structure with an adapter in accordance with aspects of the invention;

FIG. 4 is a perspective view of an embodiment of a lattice tower structure with an adapter; and,

FIG. 5 is a perspective view of an alternative embodiment of a lattice tower structure with an adapter.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
FIGS. 1 and 2 are perspective views of exemplary wind turbines 10 that may be configured in accordance with aspects of the invention. Although these wind turbines 10 are depicted as land-based structures, it should be appreciated that the invention is not limited in this regard and includes off-shore installations that utilize the adapter configuration and assembly in accordance with the invention. The wind turbines 10 include a plurality of blades 12 mounted to a rotor hub 14, which in turn is rotationally supported by any manner of power generation components housed within a machine head 16 (which is also referred to as a “nacelle”), as is well known in the art. The machine head 16 is supported atop a tower structure 18, which in the illustrated embodiments is an open lattice structure formed by columns or legs 20, horizontal braces 22, and diagonal braces 24. The columns 20 are typically angle iron members or pipe members, and the braces 22, 24 are typically angle iron members. These lattice frame tower structures 48 are also referred to in the art as “space frame” towers. The lattice tower structure 48 may be fabricated in sections and erected at the wind turbine site.
In the embodiment of FIG. 1, the lattice tower structure 18 extends essentially to the nacelle 16 such that the machine head components are supported directly atop of the tower structure 18. An adapter 30 in accordance with aspects of the invention is provided at the interface between the lattice tower structure 18 and nacelle 16, as described in greater detail below. It may be desired to provide a cladding material 26 applied over the lattice tower structure 18, which may be any type of suitable fabric, such as an architectural fabric designed for harsh weather conditions. The cladding 26 protects workers and equipment within the tower and provides an aesthetic appearance to the wind turbine 10.
In the embodiment of FIG. 2, the nacelle 16 is supported atop a tubular component 38 that is, in turn, affixed to the lattice tower structure 18 via an adapter 30. This adapter 30 may be in accordance with aspects of the present invention.
Referring to FIGS. 3 through 5 in general, the adapter 30 that is affixed to the top of the lattice tower structure 18 is a molded component that is formed directly onto the top portions 32 of the lattice tower columns 20 such that the top portions 32 are embedded directly into the adapter 30, as particularly illustrated in FIG. 3. The adapter 30 may be molded from any suitable type of settable, hardened material that may be formed directly onto the top portions 32 of the columns 20, for example by being poured into a mold that is affixed to the top of the lattice tower structure 18 during the fabrication process.
In a particular embodiment, the adapter is a concrete member, with the top portions 32 of the columns 20 embedded directly into the concrete during the formation process. It should be appreciated that concrete is not a limiting material, and that other suitable types of settable, hardened materials may be used, for example, epoxies or other hardened adhesives, hardened plastics, and so forth.
In order to strengthen and ensure the integrity of the connection between the top portions 32 of the columns 20 and the adapter 30, it may be desired to affix any manner of anchor members 34 onto the portions of the columns 20 that will be embedded in the adaptor 30, as depicted in FIG. 3. End plates or head plates may also be provided atop the columns 20 for the same purpose.
It should be appreciated that the adapter 30 is not limited to any particular shape, size, dimensions, or aesthetic appearance, and that all of these characteristics may be varied to the moldable and shapeable characteristics of the adapter 30. In the illustrated embodiment, the adapter 30 is a solid plate-like member, such as a concrete disc. In other embodiments, the adapter 30 may be a ring so that cables, ladders, and any other component may be routed through the adapter into the tubular section or machine head.
In the embodiment of FIG. 2 wherein the adapter 30 is provided at the interface of the lattice tower structure 18 and a tubular component 38, it may be desired to incorporate a plurality of anchor bolts 36 (FIG. 3) with the adapter 30. These anchor bolts 36 are configured for receipt of the bottom portion of the tubular component 38, as depicted in FIG. 3. The bolts 36 may be embedded directly into the adapter 30 and include a threaded extension that extends from the upper surface of the adapter 30, as depicted in FIG. 4. In other embodiments, the anchor bolts 36 may extend through holes that are drilled or formed into the adapter 30, as depicted by the right-hand anchor bolt 36 in FIG. 3. The anchor bolts 36 may be pre-tensioned within the adapter 30. It should be appreciated that the adapter 30 is not limited to any particular type of mechanical fastening between the adapter 30 and the tubular component 38.
In the embodiment of FIG. 1 wherein the adapter 30 constitutes the interface between the top of the lattice tower structure 18 and the nacelle 16, the adapter 30 may be configured for direct attachment with one of the machine components within the nacelle 16, such as the yaw bearing ring. In this regard, referring to FIG. 5, the adapter 30 may include a plurality of threaded inserts 44 for receipt of bolts used to attach the bearing ring to the adapter 30. In an alternative embodiment, bolt holes may be defined completely through the adapter 30, wherein bolts used to attach the bearing ring extend completely through the adapter 30 and are bolted at the underside of the adapter 30 similar to the configuration depicted in FIG. 3.
The adapter 30 may, in certain embodiments, constitute a component that is pre-formed onto a top section 40 (FIG. 3) of a lattice tower structure 18, wherein various sections of the tower structure are assembled at the wind turbine site. In this manner, the adapter 30 may be pre-formed onto a tower section 40 and transported intact with the tower section 40 to the wind turbine site. Alternatively, the adapter 30 may be formed atop the lattice tower structure 18 at the wind turbine site.
It should thus be appreciated that the present invention also encompasses any manner of a section 40 of a lattice tower structure that incorporates an adapter 30 in accordance with aspects of the present invention.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A wind turbine tower construction, comprising:

a lattice structure having a plurality of vertically oriented columns and cross-brace members; and

an adapter molded onto a top of said lattice structure such that top portions of said columns are embedded into said adapter.

2. The wind turbine tower construction as in claim 1, wherein said adapter comprises a settable, hardened material formed onto said top portions of said columns.

3. The wind turbine tower construction as in claim 2, wherein said adapter comprises a concrete member poured and formed onto said top portions of said columns.

4. The wind turbine tower construction as in claim 3, further comprising anchor members attached to said top portions of said columns and embedded in said concrete member.

5. The wind turbine tower construction as in claim 1, further comprising a plurality of anchor bolts configured with said adapter.

6. The wind turbine tower construction as in claim 5, wherein said anchor bolts are pre-tensioned in said adapter.

7. The wind turbine tower construction as in claim 1, further comprising a plurality of threaded inserts in said adapter.

8. The wind turbine tower construction as in claim 1, wherein said adapter is a continuous plate-like member.

9. The wind turbine tower construction as in claim 1, wherein said lattice tower structure comprises a plurality of vertically aligned and connected sections, said adapter pre-molded onto a top one of said sections.

10. A section of a wind turbine towerconsturction, comprising:

a plurality of vertically oriented columns and cross-brace members interconnected to define an open lattice structure; and

an adapter molded onto a top of said columns such that top portions of said columns are embedded into said adapter;

wherein said adapter is configured for receipt of a machine head component of a wind turbine.

11. The section as in claim 10, wherein said adapter comprises a settable, hardened material formed onto said top portions of said columns.

12. The section as in claim 11, wherein said adapter comprises a concrete member poured and formed onto said top portions of said columns.

13. The section as in claim 12, further comprising anchor members attached to said top portions of said columns and embedded in said concrete member.

14. The section as in claim 10, further comprising a plurality of pre-tensioned anchor bolts embedded into said adapter and configured for receipt of a tubular component.

15. The section as in claim 10, wherein said adapter is a continuous plate-like member.

16. The section as in claim 10, wherein said adapter is a ring member.