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Researchers Submit Patent Application, “Wind Turbine Rotor Blade”, for Approval (USPTO 20210088024)

Source: 
Daily Real Estate News

2021 APR 13 (NewsRx) -- By a News Reporter-Staff News Editor at Daily Real Estate News -- From Washington, D.C., NewsRx journalists report that a patent application by the inventors GODENAU, Diethelm (Aurich, DE); KREBS, Sven (Leer, DE), filed on May 18, 2018, was made available online on March 25, 2021.

The patent’s assignee is Wobben Properties GmbH (Aurich, Germany).

News editors obtained the following quote from the background information supplied by the inventors: “Technical Field

“The present invention relates to a wind turbine rotor blade as well as a wind turbine with a corresponding rotor blade.

“Description of the Related Art

“Since the rotor blades of a wind turbine are exposed to all weather conditions unprotected, at certain temperatures icing of the rotor blades can occur. In order to prevent this, rotor blade heating can be used. In this case, either heating can be provided outside on the rotor blade or heated air can be provided inside the rotor blade.

“WO 2017/021350 A1 discloses a wind turbine rotor blade with a rotor blade root region and a rotor blade tip region. Furthermore, at least one flange is provided along a longitudinal direction of the rotor blade. A deflector in the form of a drop-shaped portion can be provided on the flange in order to reduce any turbulence of the air during reflection.”

As a supplement to the background information on this patent application, NewsRx correspondents also obtained the inventors’ summary information for this patent application: “Provided is a wind turbine rotor blade which enables an improved heating of the rotor blade.

“A wind turbine rotor blade is provided with a rotor blade root region, a rotor blade tip region, a pressure side, a suction side, a leading edge, a trailing edge and at least one flange between the pressure side and the suction side and along a longitudinal direction of the rotor blade. Furthermore, a deflector is provided between one end of the at least one flange and the rotor blade tip region. At least one air scoop is provided on the flange, wherein the air scoop protrudes in a region between a first and second web.

“According to one aspect of the present invention, the rotor blade has a boundary layer extraction unit which adjoins the rotor blade tip-side end of the first and second flange. The boundary-layer extraction unit is used to extract a (turbulent) boundary layer of an air flow.

“According to a further aspect of the present invention, the boundary-layer extraction unit has a plurality of recesses.

“According to a further aspect of the present invention, a first end of the boundary-layer extraction unit adjoins a first flange and a second end of the boundary-layer extraction unit adjoins one end of the second flange.

“According to one aspect of the present invention, the rotor blade tip region has an at least partially hollow rotor blade tip. The deflector substantially closes the rotor blade tip region, wherein a first ventilation channel is provided between one end of the deflector and a nose cap, and a second air channel is provided between one end of the deflector and a trailing edge.

“Provided is a wind turbine having at least one wind turbine rotor blade described above.

“According to one aspect of the present invention, warm or heated air can be introduced or made to flow in to heat the rotor blade in the rotor blade root region. According to one aspect of the present invention, the heated air is preferably introduced in the region between the leading edge and a flange and flows along the leading edge and the flange from the rotor blade root region to the rotor blade tip region. In this case, a part of this air flow can be at least partially removed by the air scoop which is provided in the flange or a part of the air flow is deflected by the air scoop into a region between the two flanges and flows in the direction of the rotor blade root region, Alternatively to this, the heated air can flow into the region between the trailing edge and the other flange from the rotor blade root region to the rotor blade tip region.

“Thus, a wind turbine rotor blade is provided with a rotor blade root region, a rotor blade tip region, a pressure side, a suction side, at least one flange which extends along a longitudinal direction of the rotor blade. In conventional rotor blades, the rotor blade tip is typically configured to be hollow but filled with a foam filling material. This prevents an effective heating of the rotor blade tip. This can lead to ice formation in particular in the region of the rotor blade tip and results in dangerous dropping of ice as a result of the high speed of the rotor blade tip. Furthermore, a heatable blade tip with an adapted deflection in the rotor blade tip region is provided. Furthermore, a flange bulkhead can optionally be provided. For further improvement, a bypass air scoop can be provided which optimizes the flow in the deflecting region in which the boundary layer flow is extracted at the end of the flange and thus flow detachment and turbulence can be reduced.

“According to one aspect of the present invention, a deflector, for example, in the form of a foam wedge is provided in the region of the rotor blade tip. This deflector serves to deflect an air flow at the leading edge so that the trailing edge can also be heated with heated air. The foam wedge can be provided so that a part of the air can flow past it into a rotor blade tip and can flow out again in order to heat the rotor blade tip. With the rotor blade, it is possible that the main flow is guided by an integrated deflection in the direction of the blade flange whereas an auxiliary flow is guided in the nose cap region along the deflection to the rotor blade tip.

“According to one aspect of the present invention, holes can be provided in the rotor blade tip to be able to ensure removal of water from the rotor blade tip. Optionally a grid can be provided in front of an air inlet of the rotor blade tip in order to be able to prevent blocking of the water removal.

“According to one aspect of the present invention, an air scoop can be provided in the region of one of the flanges to enable a bypass. This can result in a negative pressure in the tip-side torsion channel.

“According to the invention, a volume flow of the blade heating can be increased. With the rotor blade according to the invention it is possible to optionally deflect an air flow at each flow rate and reduce a pressure loss. With the rotor blade according to the invention, flow detachment and turbulence in the deflecting region can be reduced. The rotor blade or rotor blade tip can be de-iced to reduce dropping of ice.

“With the rotor blade according to the invention, the air flow of a rotor blade heating is improved in a simple and uncomplicated manner without thereby negatively influencing the lightning protection. By means of the air scoop a negative pressure is produced in the region between the first and second flange. Thus, the air scoop serves to support the flow.

“Additionally or alternatively to this, a deflector can then be provided which has the smallest possible variation in cross-sectional area, wherein the flow channel has a small variation in cross-sectional area after installation of the deflector.

“A wind turbine rotor blade is provided which has at least one, preferably two flanges along the longitudinal direction of the rotor blade. For heating the rotor blade an air flow can be provided along the flanges. The air flow starts in the rotor blade root region and the preferably heated air flows along the first and/or second flange and must be deflected in the rotor blade tip region. In order to improve the air flow, at least one air scoop is provided in one of the flanges, wherein a hole is provided in the flange at the location of the air scoop so that by means of the air scoop a negative pressure can preferably be provided in a region between the first and second flange. For further improvement of the air flow a boundary-layer extraction unit, for example, in the form of a boundary-layer extraction plate can be provided at the free ends of the first and second flange. Between the boundary-layer extraction unit and the air scoop, a synergy effect is provided since the air scoop in the flange can produce a negative pressure in the region between the first and second flange, with the result that the boundary-layer extraction by means of the boundary-layer extraction unit is improved.

“Optionally a hollow rotor blade tip can be provided, in front of which a deflector is provided which leaves free a first and second air channel between the deflector and the shells of the rotor blade so that the hollow rotor blade tip can be heated or can have warm air flowing through it.

“According to one aspect of the present invention, at least one air scoop is provided on a first flange and between the first and second flange. In the region of the air scoop a hole must be provided in the flange so that air can flow through this hole and the air scoop in the region between the first and second flange. The air scoop firstly has the function of deflecting an air flow in a region between the first flange and a leading edge of the rotor blade in a region between the first and second flange, wherein the flow then flows further in the direction of the rotor blade root. The air scoop further has the function together with the boundary-layer extraction unit of extracting an in particular turbulent boundary layer in the region of the boundary-layer extraction unit. Together with the boundary-layer extraction unit, the air scoop acts like an ejector pump and has the result that a negative pressure is formed in the region between the first and second flange.

“According to an alternative aspect of the present invention, the air scoop can also be arranged on the second flange when the air in the region between the second flange and the end edge flows from the rotor blade root region to the rotor blade tip region.

“Alternatively to this, the air scoop can be provided both in the first and in the second flange when the air flow is guided both along the leading edge and also along the trailing edge from the rotor blade root region to the rotor blade tip region.

“According to one aspect of the present invention, the slots 281 in the boundary-layer extraction plate have a width of <=5 mm.

“Further embodiments of the invention are the subject of the claims.”

The claims supplied by the inventors are:

“1. A wind turbine rotor blade, comprising: a rotor blade root region, a rotor blade tip region, a pressure side, a suction side, a leading edge, a trailing edge, first and second flanges extending between the pressure side and the suction side and along a longitudinal direction of the rotor blade, a deflector between the rotor blade tip region and ends of the first and second flanges, wherein the deflector is configured to deflect heated air flowing from the rotor blade root region along the first and second flanges, at least one air scoop on one of the first or second flanges, and a boundary-layer extraction unit that adjoins ends of the first and second flanges at the rotor blade tip region, wherein the boundary-layer extraction unit is configured to extract a turbulent boundary layer or openings of an air flow.

“2. The wind turbine rotor blade according to claim 1, wherein the at least one air scoop protrudes in a region between first and second flanges and is configured to produce a negative pressure in a region between the first and second flanges.

“3. (canceled)

“4. The wind turbine rotor blade according to claim 1, wherein the boundary-layer extraction unit comprises a plurality of recesses.

“5. The wind turbine rotor blade according to claim 1, wherein a first end of the boundary-layer extraction unit is coupled to the first flange and a second end is coupled to the second flange.

“6. The wind turbine rotor blade according to claim 1, wherein the rotor blade tip region comprises an at least partially hollow rotor blade tip, wherein the deflector covers a portion of the rotor blade tip region, wherein the wind turbine blade further comprises a first air channel and a second air channel, wherein the first air channel is between a first end of the deflector and a nose cap, and the second air channel is between a second end of the deflector and a trailing edge.

“7. A wind turbine comprising at least one wind turbine rotor blade according to claim 1.

“8. The wind turbine rotor blade according to claim 1, wherein the boundary-layer extraction unit that is a plate coupled to ends of the first and second flanges.”

For additional information on this patent application, see: GODENAU, Diethelm; KREBS, Sven. Wind Turbine Rotor Blade. Filed May 18, 2018 and posted March 25, 2021. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220210088024%22.PGNR.&OS=DN/20210088024&RS=DN/20210088024

 

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