The subject matter disclosed herein relates to wind turbine rotor blades and, more specifically, to modular extensions for modified wind turbine rotor blades.
Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades capture kinetic energy of wind using known foil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
The particular size of wind turbine rotor blades is a significant factor contributing to the overall efficiency of the wind turbine. Specifically, increases in the length or span of a rotor blade may generally lead to an overall increase in the energy production of a wind turbine. Accordingly, efforts to increase the size of rotor blades aid in the continuing growth of wind turbine technology and the adoption of wind energy as an alternative energy source. However, modifying designs and manufacturing processes for new rotor blades may require significant resources.
Accordingly, alternative rotor blades would be welcome in the art.
In one embodiment, a rotor blade for a wind turbine is provided. The rotor blade includes an inner portion and a modular extension attached to the inner portion and forming a new span length for the rotor blade. The modular extension includes one or more spanwise support elements connecting to the inner portion and extending in a spanwise direction, a plurality of cross-sectional ribs disposed along a length of the one or more spanwise support elements, and, a modular extension shell surrounding the modular extension supported by the plurality of cross-sectional ribs.
In another embodiment, a method for modifying a rotor blade is provided. The method includes providing an inner portion, connecting one or more spanwise support elements to the inner portion such that the one or more spanwise support elements extend in a spanwise direction, connecting a plurality of cross-sectional ribs to the one or more spanwise support elements, the plurality of cross-sectional ribs disposed along a length of the one or more spanwise support elements, and, connecting a modular extension shell that surrounds and is supported by the plurality of cross-sectional ribs.
These and additional features provided by the embodiments discussed herein will be more fully understood in view of the following detailed description, in conjunction with the drawings.
The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the inventions defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
Referring to
Referring to
Referring to
The inner blade portion 160 can further comprise any and all internal structural elements present in the original rotor blade 100. For example, the inner blade portion 160 can comprise the internal support structure 140 utilized to provide structural support to the original rotor blade 100 along its span 118. In some embodiments, such as that illustrated in
The inner portion 150 may be separated from the outer portion 160 through any suitable system. For example, the inner portion 150 may be separated using saws, blades, torches, lasers or any other suitable device. In some embodiments, the inner portion 150 may have been manufactured without an outer portion 160 such that separation of the two portions is not required. Moreover, the inner portion 150 may comprise any length or percentage of the original rotor blade 100 suitable for connection with a subsequent modular extension 201. For example, in some embodiments the inner portion 150 may comprise only the first 5-10 meters of the original rotor blade 100. In other embodiments, the inner portion 150 may comprise the first 25%, 50% or more of the original rotor blade 100. In some embodiments, such as that illustrated in
Referring now to
As will become appreciated herein, the modular extension 201 can be utilized to extend or shorten the original rotor blade 100 or complete a new make rotor blade by using a plurality of modular components. In some embodiments, the modular components may be customized (e.g., cut) in the field to suit individual blade requirements. In some embodiments, the modular components may be provided in a variety of preselected sizes. The modular extension 201 can thereby allow for the modification of an original rotor blade 100 or new make rotor blade either in the field (e.g., at or near the site of the wind turbine 10), in a maintenance facility and/or at the place of original manufacturing.
As best illustrated in
The one or more spanwise support elements 210 can comprise any material or materials suitable for supporting the modular extension 201. For example, the one or more spanwise support elements 210 may comprise any suitable composite material, fiber material, laminate material, metal, alloy or the like. When there are multiple spanwise support elements 210, each of these spanwise support elements 210 can comprise the same material or different materials. Additionally, the one or more spanwise support elements 210 can comprise the same material or a different material than the internal support structure 140.
In some embodiments, such as that illustrated in
The plurality of spanwise support elements 211 can connect to the inner portion 150 through a variety of suitable connections. For example, in some embodiments, such as when the inner portion 150 comprises a spar cap 142, the plurality of spanwise support elements 211 may be connected to the spar cap 142 such that their loads are distributed there between. The plurality of spanwise support elements may taper toward the spar cap 142 once in the inner portion 150 (such as illustrated in
In some embodiments, the plurality of spanwise support elements 211 may all extend substantially parallel to one another in the spanwise direction (e.g., the same general direction as the internal support structure 140 of the inner portion 150). In other embodiments, the plurality of support elements 211 may extend as a truss-like or lattice-like network such that individual support elements 211 extend in different directions but combine to form a supporting structure for the modular extension 201.
The plurality of spanwise support elements 211 may further comprise any cross-sectional configuration and length suitable to support the modular extension 201 as should be appreciated herein. For example, in some embodiments, the plurality of spanwise support elements 211 may comprise a “C” shaped cross-section (as illustrated in
Moreover, in some embodiments, each of the plurality of spanwise support elements 211 may have the same initial length L. In such embodiments, the final lengths of each of the spanwise support element 211 can be customized (via cutting, grinding, sawing, or the like) for that specific rotor blade 200 at that specific location. In some embodiments, the plurality of spanwise support elements 211 may be selected a group of spanwise support elements 211 having a set amount predetermined lengths. For example, the plurality of spanwise support elements 211 may be selected from a certain predetermined length options based on the desired extension length for that particular rotor blade 200.
In some embodiments, such as that illustrated in
The single spanwise support elements 212 in such embodiments can connect to the inner portion 150 through a variety of suitable connections. For example, in some embodiments, such as when the inner portion 150 comprises a shear web 141, the single spanwise support element 212 may be connected directly or indirectly to the shear web 141 such that their loads are distributed there between. In such embodiments, the single spanwise support element 212 may connect to the shear web 141 via a tapered connection, rabbit fit connection, overlapping connection or any other suitable connection configuration. Moreover, the single spanwise support element 212 may be secured to the shear web 141 via any suitable adhesive, bolts, screws, pins, laminates or the like. In some embodiments the single spanwise support element 212 may be configured to connect to a standardized root stub of the inner portion. The standardized root stub can have a standard connection and profile that facilitates future connections with future spanwise support elements 210 such as those in the modular extensions 201. The standardized root stub may extend past the remainder of the inner portion 150 (such that it will at least partially extends into the modular extension 201), be flush with the edge of the inner portion 150, or even be recessed within the inner portion 150.
The single spanwise support element 212 may further comprise any cross-sectional configuration and length suitable to support the modular extension 201 as should be appreciated herein. For example, in some embodiments, the single spanwise support elements 21 may comprise an “I” shaped cross-section (similar to a traditional shear web and spar cap design or a commercially available I-beam), a cylindrical cross-section, linear cross-section, or any other suitable design.
In some embodiments, the length L of the single spanwise support element 212 may be selected from a group of spanwise support elements having a set amount of predetermined lengths. For example, a group of spanwise support elements may be available having a short, intermediate, or extended length. In some embodiments, such options may correspond to overall blade lengths (e.g., 120 meters, 127 meters, 135 meters, 141 meters, etc.) The single spanwise support element 212 may thus be selected based on the desired final length for the rotor blade 200. In other embodiments, the single spanwise support element 212 may have a length that is customizable such that it can be reduced on-site for that specific rotor blade 200.
Referring now to
In some embodiments, the plurality of cross-sectional ribs 220 may be evenly distributed along the length L of the spanwise support elements 210. In other embodiments, the plurality of cross-sectional ribs 220 may be spaced closer together or farther apart as they approach the new blade tip 206 of the modular extension 201. Furthermore, the plurality of cross-sectional ribs 220 may decrease in cross-sectional size as they approach the new blade tip 206 of the modular extension 201. For example, as illustrated in
The plurality of cross-sectional ribs 220 may connect to and be installed with the one or more spanwise support elements 210 in a variety of methods. For example, in some embodiments, the one or more spanwise support elements 210 may slide over or through each of the plurality of cross-sectional ribs 220 as illustrated in
In embodiments comprising a plurality of spanwise support elements 211 (such as illustrated in
Referring now specifically to
Referring now to
In some embodiments, the modular extension shell 230 may comprise a plurality of composite sections 231, 232 and 233 connected at a plurality of seems 238. For example, referring to
In other embodiments, the modular extension shell 230 may comprise a single piece. For example, the modular extension shell 230 may comprise a tensioned fabric wrapped around the plurality of cross-sectional ribs 220. As should be appreciated to those skilled in the art, the tensioned fabric can be wrapped around the outer circumference of the plurality of cross-sectional ribs 220 to define the aerodynamic profile and may comprise any material suitable to capture incoming wind to facilitate the rotation of the rotor blade 200.
The modular extension shell 230 may merge with the shell 108 of the inner portion 150 through any suitable configuration. For example, the two shells may overlap, meet at a seam, taper into one another, or possess any other suitable connection.
As best illustrated in
The modular extension 201 thereby combines with the inner portion 150 to form the rotor blade 200. The rotor blade 200 has a new span length SLN (
Referring now also to
The method 300 further comprises connecting a plurality of cross-sectional ribs 220 to the one or more spanwise support elements 210 in step 330. As also discussed above, the plurality of cross-sectional ribs 220 can be disposed about the length of the one or more spanwise support elements such that they can subsequently define the aerodynamic profile of the modular extension 201. It should be appreciated that connecting the cross-sectional ribs in step 330 and connecting the spanwise support elements in step 320 can occur in any relative order.
Finally, the method 300 can further comprise connecting the modular extension shell 230 in step 340. As discussed above, the modular extension shell can surround and be supported by the plurality of cross-sectional ribs 220 such that it forms the aerodynamic profile of the modular extension. The modular extension shell 230 may comprise any number of components, any material or materials, and any connection mechanisms suitable for a wind turbine rotor blade.
It should now be appreciated that rotor blades may be modified with modular extensions to produce rotor blades of different lengths. When modifying preexisting rotor blades, the new, modified rotor blades can have different span lengths than the original rotor blades to allow for more readily available customization. For example, using modular or standardized components, the modular extensions can be retrofitted onto the inner portions of original rotor blades. This can provide more conducive customization for increased efficiency based on the operational requirements for each individual rotor blade.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.