CA2818201C

CA2818201C - Noise reducer for rotor blade in wind turbine

Info

Publication number: CA2818201C
Application number: CA2818201A
Authority: CA
Inventors: Lihua Liu
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2010-11-30
Filing date: 2010-11-30
Publication date: 2014-11-18
Anticipated expiration: 2030-11-30
Also published as: EP2646682A4; CA2818201A1; EP2646682A1; WO2012071679A1; US20130272892A1

Abstract

A rotor blade assembly for a wind turbine is disclosed. The rotor blade assembly includes a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root. The rotor blade assembly further includes a mounting plate and a noise reducer. The mounting plate is configured on a surface of the rotor blade. The noise reducer may include a base plate and a plurality of noise reduction features. The base plate is mounted to the mounting plate. The plurality of noise reduction features extend from the base plate.

Description

NOISE REDUCER FOR ROTOR BLADE IN WIND TURBINE
FIELD OF THE INVENTION
[0001] The present disclosure relates in general to wind turbine rotor blades, and more particularly to noise reducers mounted to the rotor blades.
BACKGROUND OF THE INVENTION

[0002] 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.

[0003] In many cases, various components are attached to the rotor blades of wind turbines to perform various functions during operation of the wind turbines.
These components may frequently be attached adjacent to the trailing edges of the rotor blades. For example, noise reducers may be attached to the trailing edges of the rotor blades to reduce the noise and increase the efficiency associated with the rotor blade.

[0004] Typical prior art noise reducers are mounted directly to a surface of the rotor blade using glue or another suitable adhesive. These noise reducers may have a variety of disadvantages. For example, the noise reducers are generally mounted to rotor blades during manufacturing before the rotor blades are transported to the wind turbine site. The noise reducers are thus easily susceptible to damage during transportation. Additionally, the adhesives used to mount the noise reducers make replacement of the noise reducers difficult, expensive, and time consuming.
Further, during operation of a wind turbine, the noise reducers are particularly vulnerable to damage from lightning strikes. The lightning strikes may additionally damage the rotor blade as a result of contact with the noise reducers.

[0005] Thus, an improved noise reducer for a rotor blade would be desired.
For example, a noise reducer that allows for on-site mounting to a rotor blade would be advantageous. Further, a noise reducer that allows for relatively easy, cost-effective, and efficient replacement would be advantageous. Additionally, a noise reducer that reduces the vulnerability of the noise reducer and rotor blade to damage from lightning strikes would be desired.
BRIEF DESCRIPTION OF THE INVENTION

[0006] 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.

[0007] In one embodiment, a rotor blade assembly for a wind turbine is disclosed.
The rotor blade assembly includes a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root. The rotor blade assembly further includes a mounting plate and a noise reducer.
The mounting plate is configured on a surface of the rotor blade. The noise reducer includes a base plate and a plurality of noise reduction features. The base plate is mounted to the mounting plate. The plurality of noise reduction features extend from the base plate.

[0008] In another embodiment, a rotor blade assembly for a wind turbine is disclosed. The rotor blade assembly includes a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root, the surfaces further defining a rotor blade interior. The rotor blade assembly further includes a lightning protection device, a mounting plate and a noise reducer. The lightning protection device is disposed at least partially in the rotor blade interior. The mounting plate is configured on a surface of the rotor blade and is operatively connected to the lighting protection device. The noise reducer is mounted to the mounting plate.

[0009] 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

[0010] 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:

[0011] FIG. 1 is a perspective view of one embodiment of a wind turbine of the present disclosure;

[0012] FIG. 2 is a perspective view of one embodiment of a rotor blade assembly of the present disclosure;

[0013] FIG. 3 is a sectional perspective view of one embodiment of a rotor blade assembly of the present disclosure;

[0014] FIG. 4 is a cross-sectional view of another embodiment of a rotor blade assembly of the present disclosure;

[0015] FIG. 5 is a cross-sectional view of another embodiment of a rotor blade assembly of the present disclosure;

[0016] FIG. 6 is a cross-sectional view of another embodiment of a rotor blade assembly of the present disclosure; and, [0017] FIG. 7 is a cross-sectional view of another embodiment of a rotor blade assembly of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION

[0018] 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 of the invention described. 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 invention.

[0019] FIG. 1 illustrates a wind turbine 10 of conventional construction.
The wind turbine 10 includes a tower 12 with a nacelle 14 mounted thereon. A
plurality of rotor blades 16 are mounted to a rotor hub 18, which is in turn connected to a main flange that turns a main rotor shaft. The wind turbine power generation and control components are housed within the nacelle 14. The view of FIG. 1 is provided for illustrative purposes only to place the present invention in an exemplary field of use.
It should be appreciated that the invention is not limited to any particular type of wind turbine configuration.

[0020] Referring to FIG. 2, a rotor blade 16 according to the present disclosure may include surfaces defining a pressure side 22 (see FIGS. 3 through 7) and a suction side 24 extending between a leading edge 26 and a trailing edge 28.
The rotor blade 16 may extend from a blade tip 32 to a blade root 34. The surfaces defining the pressure side 22, suction side 24, leading edge 26, and trailing edge 28 further define a rotor blade interior 40.

[0021] In some embodiments, the rotor blade 16 may include a plurality of individual blade segments aligned in an end-to-end order from the blade tip 32 to the blade root 34. Each of the individual blade segments may be uniquely configured so that the plurality of blade segments define a complete rotor blade 16 having a designed aerodynamic profile, length, and other desired characteristics. For example, each of the blade segments may have an aerodynamic profile that corresponds to the aerodynamic profile of adjacent blade segments. Thus, the aerodynamic profiles of the blade segments may form a continuous aerodynamic profile of the rotor blade 16.
Alternatively, the rotor blade 16 may be formed as a singular, unitary blade having the designed aerodynamic profile, length, and other desired characteristics.

[0022] The rotor blade 16 may, in exemplary embodiments, be curved. Curving of the rotor blade 16 may entail bending the rotor blade 16 in a generally flapwise direction and/or in a generally edgewise direction. The flapwise direction may generally be construed as the direction (or the opposite direction) in which the aerodynamic lift acts on the rotor blade 16. The edgewise direction is generally perpendicular to the flapwise direction. Flapwise curvature of the rotor blade 16 is also known as pre-bend, while edgewise curvature is also known as sweep. Thus, a curved rotor blade 16 may be pre-bent and/or swept. Curving may enable the rotor blade 16 to better withstand flapwise and edgewise loads during operation of the wind turbine 10, and may further provide clearance for the rotor blade 16 from the tower 12 during operation of the wind turbine 10.

[0023] As illustrated in FIGS. 2 through 7, the present disclosure may further be directed to a rotor blade assembly 100. The rotor blade assembly 100 may include a rotor blade 16, a mounting plate 110, and a noise reducer 112. In general, the mounting plate 110 may be configured to couple the noise reducer 112 to the rotor blade 16. The noise reducer 110 may be configured to reduce the aerodynamic noise being emitted from the rotor blade 16 during operation of the wind turbine 10 and/or may increase the efficiency of the rotor blade 16.

[0024] As mentioned, the mounting plate 110 may be configured to couple the noise reducer 112 to the rotor blade 16. In exemplary embodiments, the mounting plate 110 may be formed from a metal or metal alloy. For example, the mounting plate 110 may be formed from aluminum. Alternatively, however, the mounting plate 110 may be formed from any suitable material. For example, in some embodiments, the mounting plate 110 may be formed from a material suitable to conduct the electrical current from lightning strikes, as discussed below. Alternatively, the mounting plate 110 may be formed from any material suitable for coupling the noise reducer 112 to the rotor blade 16.

[0025] The mounting plate 110 may be configured on a surface of the rotor blade 16. For example, in some embodiments as illustrated in FIGS. 2 through 6, the mounting plate 110 may extend from a surface of the rotor blade 16. As shown, the mounting plate 110 may be configured on, and extend from, the trailing edge 28 of the rotor blade 16.

[0026] In exemplary embodiments as shown in FIGS. 2 through 6, the mounting plate 110 may be disposed between the pressure side 22 and the suction side 24 of the rotor blade 16. In these embodiments, the rotor blade 16 may be formed from one or more shell portions. For example, one shell portion may include the pressure side 22 and extend between the leading edge 26 and the trailing edge 28, while another shell portion may include the suction side 24 and extend between the leading edge 26 and the trailing edge 28. The mounting plate 110 may be disposed between these shell portions such that a portion of the mounting plate 110 is disposed in the interior 40 of the rotor blade 16, while another portion extends from the rotor blade 16. In exemplary embodiments, the mounting plate 110 may be disposed between the pressure side 22 and the suction side 24 at the trailing edge 28, such that the mounting plate 110 is configured on the trailing edge 28. A suitable adhesive 113 or, alternatively, suitable mechanical fasteners, may be utilized to secure the mounting plate 110 as required.

[0027] In alternative embodiments, the mounting plate 110 may extend through a surface of the rotor blade 16. For example, the mounting plate 110 may extend through a shell portion of the rotor blade 16 at a desired location, such as at the trailing edge 28, such that a portion of the mounting plate 110 is disposed in the interior 40 of the rotor blade 16, while another portion extends from the rotor blade 16.
A suitable adhesive 113 or, alternatively, suitable mechanical fasteners, may be utilized to secure the mounting plate 110 as required.

[0028] In further alternative embodiments, the mounting plate 110 may be mounted directly to the exterior of the rotor blade 16 through the use of, for example, a suitable adhesive 113 or suitable mechanical fasteners. For example, the mounting plate 110 may be mounted between the pressure side 22 and the suction side 24, such as, for example, mounted directly to the trailing edge 28.

[0029] In other alternative embodiments, as shown in FIG. 7, the mounting plate 110 may be co-infused with a surface of the rotor blade 16. For example, the mounting plate 110 may be co-infused with the pressure side 22, as shown in FIG. 7, or the suction side 24. To be co-infused with a surface of the rotor blade 16, the mounting plate 110 is formed into the surface. For example, the blade skin 114 forming the exterior of, for example, the pressure side 22 or suction side 24 of the rotor blade 16 may be formed around both the mounting plate 110 and the material 116 forming the interior of the pressure side 22 or suction side 24, such that the mounting plate 110 is formed into the pressure side 22 or suction side 24. The blade skin 114 may further be infused together with the interior material 116 and/or the mounting plate 110 to form, for example, the pressure side 22 or the suction side 24.

[0030] As shown in FIGS. 2 through 7, the rotor blade assembly 100 of the present disclosure may further include a lightning protection device 120. In general, the lightning protection device 120 protects the rotor blade 16 and wind turbine 10 in general from lightning strikes. In exemplary embodiments, the lightning protection device 120 is a cable, such as a copper cable. The lighting protection device 120 may be disposed at least partially in the interior 40 of the rotor blade 16. For example, the lightning protection device 120 may extend in the interior 40 through at least a portion of the length of the rotor blade 16. Further, the lightning protection device 120 may be connected at various locations along the length of the rotor blade 16 to one or more electrically conducting lightning receptors (not shown) disposed on one or more of the surfaces of the rotor blade 16. The lightning protection device 120 may further be in conductive communication with a grounding system in the wind turbine 10, such as in the tower 12 of the wind turbine 10. Thus, in general, when lightning strikes the rotor blade 16, the electrical current flows from the lightning receptors through the lightning protection device 120 to the ground, thereby preventing damage to the wind turbine 10.

[0031] In exemplary embodiments, the mounting plate 110 may be operatively connected to the lightning protection device 120. When the mounting plate 110 and lightning protection device 120 are operatively connected, the lightning protection device 120 may protect the mounting plate 110 and noise reducer 112 from lightning strikes. Thus, for example, the electrical current from lightning striking the mounting plate 110 or the noise reducer 112, discussed below, may flow through the mounting plate 110 to the lightning protection device 120. In some embodiments, a conduction cable 122 or a plurality of conduction cables 122 may be provided to operatively connect the mounting plate 110 to the lightning protection device 120. The conduction cable 122 is connected at one end to the mounting plate 110 and at the other end to the lightning protection device 120. Electrical current from lightning strikes to the mounting plate 110 or the noise reducer 112 may thus flow from the mounting plate 110 through the conduction cable 122 to the lightning protection device 120.

[0032] As discussed above, the mounting plate 110 couples the noise reducer to the rotor blade 16. Thus, the noise reducer 112 may be mounted to the mounting plate 110. The noise reducer 112 may be formed from any suitable material for reducing the noise and/or increasing the efficiency associated with the rotor blade 16 and wind turbine 10. In some embodiments, the noise reducer may be formed from a metal or metal alloy, such as aluminum, or from any material suitable to conduct the electrical current from lighting strikes, as discussed above. In alternative embodiments, the noise reducer may be formed from any suitable non-conductive materials, such as from a glass-reinforced plastic composite.

[0033] The noise reducer 112 may further include a plurality of noise reduction features 130. As described herein and illustrated in FIGS. 2 and 3, the noise reduction features 130 in exemplary embodiments are serrations 132. However, it should be understood that the noise reduction features 130 are not limited to serrations 132. For example, in some alternative embodiments the noise reduction features 130 may be bristles. Further, any suitable noise reduction features 130 are within the scope and spirit of the present disclosure.

[0034] As shown in FIGS. 2 through 7, the noise reduction features 130, such as the serrations 132, may extend generally from the mounting plate 110. While in exemplary embodiments the serrations 132 are generally V-shaped, as shown in FIGS.
2 and 3, in alternative embodiments the serrations 132 may be U-shaped, or may have any other shape or configuration suitable for reducing the noise being emitted from and/or increasing the efficiency of the rotor blade 16 during operation of the wind turbine 10.

[0035] It should be understood that the noise reduction features 130 according to the present disclosure may have any suitable characteristics, such as widths, lengths, shapes, or orientations, depending on the desired noise reduction characteristics for the noise reducer 110. Further, individual noise reduction features 130 may have individual characteristics, or various groups of noise reduction features 130 may have similar characteristics, or all noise reduction features 130 may have similar characteristics, depending on the desired noise reduction characteristics for the noise reducer 110.

[0036] In some exemplary embodiments, as shown in FIGS. 2 through 7, the noise reducer 112 may include a base plate 134. The base plate 134 in these embodiments may generally be that portion of the noise reducer 110 that is mounted to the mounting plate 110, and the noise reduction features 130 may extend from the base plate 134. Alternatively, the noise reduction features 130 may be mounted directly to the mounting plate 110, and extend directly from the mounting plate 110.

[0037] FIGS. 2 through 7 illustrate various apparatus for mounting the noise reducer 112 to the mounting plate 110. In some embodiments, as shown in FIGS.
2, 3, and 7, for example, at least one mechanical fastener 140 or a plurality of mechanical fasteners 140 may be provided to mount the noise reducer 112 to the mounting plate 110. The mechanical fasteners may be, for example, nut/bolt combinations, rivets, screws, nails, or any other suitable mechanical fasteners. The mechanical fasteners may extend through the noise reducer 112 and mounting plate 110 to secure the noise reducer 112 and mounting plate 110 together.

[0038] In other embodiments, as shown in FIGS. 4 through 6, a male fastening device 142 and a female fastening device 144 may be provided to mount the noise reducer 112 to the mounting plate 110. In general, the male fastening device 142 and the female fastening device 144 may be configured to couple the noise reducer and the mounting plate 110 together. The mounting plate 110 may include one of the male fastening device 142 and the female fastening device 144, and the noise reducer may include the other of the male fastening device 142 and the female fastening device 144.

[0039] For example, FIG. 4 illustrates one embodiment of the male fastening device 142 and the female fastening device 144. In this embodiment, the male fastening device 142 is included on the mounting plate 110 and the female fastening device 144 is included on the noise reducer 112. It should be understood, however, that in other embodiments, the male fastening device 142 may be include on the noise reducer 112 and the female fastening device 144 included on the mounting plate 110.
As shown, the male fastening device 142 is an end portion 152 of the mounting plate 110 configured to protrude into the female fastening device 144. The female fastening device 144 is a bracketed portion 154 of the noise reducer 112 configured to accept the male fastening device 144. As shown, the bracketed portion 154 is a generally U-shaped bracket. However, it should be understood that the bracketed portion 154 may have any shape suitable for accepting a male fastening device therein. In some exemplary embodiments, as shown in FIG. 4, various mechanical fasteners 140 may further be included to mount the noise reducer 112 to the mounting plate 110.

[0040] FIG. 5 illustrates another embodiment of the male fastening device and the female fastening device 144. In this embodiment, the male fastening device 142 is included on the mounting plate 110 and the female fastening device 144 is included on the noise reducer 112. It should be understood, however, that in other embodiments, the male fastening device 142 may be include on the noise reducer and the female fastening device 144 included on the mounting plate 110. As shown, the male fastening device 142 is a head portion 162 of the mounting plate 110 configured to protrude into the female fastening device 144. The female fastening device 144 is a socket portion 164 of the noise reducer 112 configured to accept the male fastening device 144. As shown, the head portion 162 and socket portion are generally spherically-shaped. However, it should be understood that the head portion 162 and socket portion 164 may have any shapes suitable for engaging each other. In some embodiments, the socket portion 164 may be a snap-fit socket portion 164, such that the head portion 162 may be snap-fit into the socket portion 164. Thus, the head portion 162 and socket portion 164 may be engaged in the generally chord-wise direction relative to the rotor blade 16. Additionally or alternatively, the head portion 162 and socket portion 164 may be engaged in the generally span-wise direction relative to the rotor blade 16 by sliding the head portion 162 through the socket portion 164 in the generally span-wise direction. Further, in some embodiments, various mechanical fasteners 140 may be included to mount the noise reducer 112 to the mounting plate 110.

[0041] FIG. 6 illustrates another embodiment of the male fastening device and the female fastening device 144. In this embodiment, the male fastening device 142 is included on the noise reducer 112 and the female fastening device 144 is included on the mounting plate 110. It should be understood, however, that in other embodiments, the male fastening device 142 may be include on the mounting plate 110 and the female fastening device 144 included on the noise reducer 112. As shown, the male fastening device 142 is an offset end portion 172 of the mounting plate 110 configured to protrude into the female fastening device 144. The offset end portion 172 defines an engagement wall 173. The female fastening device 144 is a bracketed portion 174 of the noise reducer 112 configured to accept the male fastening device 144. As shown, the bracketed portion 174 is a generally U-shaped bracket. However, it should be understood that the bracketed portion 174 may have any shape suitable for accepting a male fastening device 144 therein. The bracketed portion 174 may include an engagement lip 175. When the male fastening device and the female fastening device 144 are coupled together, the engagement wall and engagement lip 175 may engage each other. Advantageously, when the wind turbine 10 is in operation and the rotor blade 16 is moving, the engagement lip 175 may thus accept the centrifugal load of the noise reducer 112 as transmitted through the engagement wall 173. In some exemplary embodiments, as shown in FIG. 6, various mechanical fasteners 140 may further be included to mount the noise reducer 112 to the mounting plate 110.

[0042] The embodiments as disclosed above for mounting the noise reducer 112 to the mounting plate 110 may, advantageously, allow for the noise reducers 112 to be efficiently and cost-effectively mounted to rotor blades 16 on-site. Further, the above embodiments may allow for efficient and cost-effective replacement of the noise reducers 112 as required.

[0043] It should be understood that, while FIGS. 2 through 7 illustrate various embodiments of apparatus for mounting the noise reducer 112 to the mounting plate 110, any suitable apparatus for mounting the noise reducer 112 to the mounting plate 110 are within the scope of the present disclosure.

[0044] 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 in view of the teachings of the description.

Claims

1. A rotor blade assembly for a wind turbine, comprising:
a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root;
a mounting plate configured on a surface of the rotor blade; and, a noise reducer, the noise reducer comprising a base plate and a plurality of noise reduction features, the base plate fastened to the mounting plate, the plurality of noise reduction features extending from the base plate.

2. The rotor blade assembly of claim 1, wherein the mounting plate extends through a surface of the rotor blade.

3. The rotor blade assembly of claim 1, wherein the mounting plate and one of the pressure side and the suction side are co-infused.

4. The rotor blade assembly of claim 1, wherein the mounting plate is disposed between the pressure side and the suction side.

5. The rotor blade assembly of claim 1, wherein the mounting plate is configured on the trailing edge.

6. The rotor blade assembly of claim 1, wherein the surfaces of the rotor blade further define a rotor blade interior, wherein the rotor blade further comprises a lightning protection device disposed at least partially in the rotor blade interior, and wherein the mounting plate is operatively connected to the lighting protection device.

7. The rotor blade assembly of claim 6, further comprising a conduction cable operatively connecting the mounting plate to the lightning protection device.

8. The rotor blade assembly of claim 1, further comprising at least one mechanical fastener mounting the base plate to the mounting plate.

9. The rotor blade assembly of claim 1, wherein the mounting plate includes one of a male fastening device or a female fastening device, wherein the base plate includes the other of the male fastening device or the female fastening device, and wherein the male fastening device and female fastening device are configured to couple the base plate and the mounting plate together.

10. The rotor blade assembly of claim 1, wherein the plurality of noise reduction features are a plurality of serrations.

11. The rotor blade assembly of claim 6, wherein the mounting plate extends through a surface of the rotor blade.

12. The rotor blade assembly of claim 6, wherein the mounting plate and one of the pressure side and the suction side are co-infused.

13. The rotor blade assembly of claim 6, wherein the mounting plate is disposed between the pressure side and the suction side.

14. The rotor blade assembly of claim 6, wherein the mounting plate is configured on the trailing edge.

15. The rotor blade assembly of claim 6, further comprising at least one mechanical fastener mounting the noise reducer to the mounting plate.

16. The rotor blade assembly of claim 6, wherein the mounting plate includes one of a male fastening device or a female fastening device, wherein the noise reducer includes the other of the male fastening device or the female fastening device, and wherein the male fastening device and female fastening device are configured to couple the noise reducer and the mounting plate together.

17. The rotor blade assembly of claim 6, wherein the plurality of noise reduction features are a plurality of serrations.