Rotor blade, wind turbine, serration angle, environmental parameters

Patent metadata

Field	Value
Publication number	US-12066004-B2
Application number	US-202318169616-A
Country	US
Kind code	B2
Filing date	Feb 15, 2023
Priority date	Feb 15, 2022
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

A rotor blade of a wind turbine, to an associated wind turbine, to an associated wind farm and to associated methods. The rotor blade has a leading edge and a trailing edge and extends in a longitudinal direction of the rotor blade between a root end and a tip end, wherein a direct connection between the leading edge and the trailing edge is referred to as a chord line, wherein the rotor blade has serrations in the region of the trailing edge at least in some section or sections, wherein each of the serrations has a base line, which is arranged at the trailing edge, and an end point, which is furthest away from the base line, which together span a plane of the serration, wherein an angle between the plane of at least one of the serrations and the profile chord of the rotor blade is formed as a function of at least one environmental parameter at the installation location of the wind turbine.

First claim

The invention claimed is:

1. A rotor blade of a wind turbine comprising:
a rotor blade body having a leading edge and a trailing edge, the rotor blade body extending in a longitudinal direction between a root end and a tip end,
wherein a cross section of rotor blade body between the leading edge and the trailing edge defines a profile chord,
wherein the rotor blade has a plurality of serrations formed by teeth of a trailing edge ridge of the rotor blade,
wherein each serration of the plurality of serrations has a base line arranged at the trailing edge, and an end point, which is located furthest away from the base line, which together span a plane of the serration,
wherein an angle between the plane of at least one serration of the plurality of serrations and the profile chord is formed dependent on at least one environmental parameter at an installation location of the wind turbine, and
wherein the angle between the plane of the at least one serration of the plurality of serrations and the profile chord is increased in the direction of a pressure side of the rotor blade as the air density decreases thereby adjusting an induction factor distribution of the rotor blade according to deviations of the at least one environmental parameter at the installation location from at least one design parameter of the rotor blade.

2. The rotor blade according to claim 1 , wherein the at least one environmental parameter at the installation location of the wind turbine includes one or more parameters chosen from air density, air humidity, temperature, air pressure, air pollution, turbulence or turbulence intensity, shear, and wind speed, wherein the at least one environmental parameter comprises a value chosen from an extreme value, an average value, and a variance of the air density, air humidity, temperature, air pressure, air pollution, turbulence or turbulence intensity, shear, and wind speed, wherein an extreme value is a high value or a low value within past 5 years.

3. The rotor blade according to claim 1 , wherein the respective angles between the planes of the plurality of serrations and the profile chord is different for at least two serrations of the plurality of serrations.

4. The rotor blade according to claim 1 , wherein the angle between the plane of at least one serration of the plurality of serrations and the profile chord is dependent on the at least one environmental parameter and a mounting position of the respective serration in the longitudinal direction of the rotor blade.

5. The rotor blade according to claim 1 , wherein in an event of a deviation from a design air density at the installation location, the angle between the plane of in each case one serration of the plurality of serrations and the profile chord has an absolute value greater than 0 degrees for at least one serration of the plurality of serrations.

6. The rotor blade according to claim 1 , wherein the environmental parameter comprises an extreme value, an average value, and/or a variance of the air density, and wherein the angle between the plane of at least one serration of the plurality of serrations and the profile chord increases in the direction of the pressure side with decreasing air density.

7. The rotor blade according to claim 6 , wherein the angle is more than 4 degrees in the direction of the pressure side at an air density that is less than 0.075 kg/m 3 .

8. The rotor blade according to claim 1 , wherein an average of the angles between the respective planes of the plurality of serrations and the profile chord at an air density at the installation location, which is equal to or less than a design air density, is greater in a direction of the pressure side than an average angle between the respective planes of the plurality of serrations and the profile chord of the respective rotor blade body, which has been optimized for an air density above the design air density.

9. The rotor blade according to claim 1 , wherein the angle between the plane of at least one serration of the plurality of serrations and the profile chord is formed such that:
the serration has a curvature between a location at which the serration is mounted on the rotor blade and another location on the serration, and/or
the serration is mounted on a movable part of the rotor blade, wherein the movable part of the rotor blade is configured to be adjusted in such a way that the angle between the serration and the profile chord is variable, and/or
the serration has a hinge, wherein the hinge is configured to be adjusted in such a way that the angle between the serration and the profile chord is variable, and/or
the serration is mounted on the rotor blade in such a way that the angle between the plane of the serration and the profile chord deviates from zero such that the rotor blade is not parallel to the profile chord at the mounting point of the serration, and/or
the serration is angled by compression, tension, or stress in that a tension or compression mechanism acts on the serration create the angle.

10. The rotor blade according to claim 1 , wherein lengths of the plurality of serrations from the base line to the at least one end point are dependent on the angle between at least one of the plurality of serrations and the profile chord.

11. The rotor blade according to claim 1 , wherein the angle between the plane of at least one serration of the plurality of serrations and the profile chord is configured to be adjusted during an operation of the wind turbine.

12. The rotor blade according to claim 1 , wherein the angle between at least one serration of the plurality of serrations and the profile chord is configured to be adjusted dependent on the mounting position in the longitudinal direction of the rotor blade to optimize lifting of the rotor blade such that a yield of the wind turbine is maximized dependent on the position in the longitudinal direction of the rotor blade, and wherein an induction distribution of the rotor blade is configured to be optimized such that the yield of the wind turbine is maximized in a manner dependent on the location by corresponding adjustment of the angle.

13. A wind turbine comprising:
at least one rotor blade according to claim 1 , and
a controller configured to adapt at least one operating point of the wind turbine dependent on the angle between at least one serration of the plurality of serrations and the profile chord.

14. A method comprising:
providing the wind turbine of claim 13 ; and
adapting an angle of the at least one serration of the rotor blade,
wherein adapting comprises adapting the angle between the plane of the plurality of serrations and the profile chord dependent on at least one environmental parameter at the installation location of the wind turbine.

15. A method for optimizing a rotor blade having a rotor blade body with a leading edge and a trailing edge that extends in a longitudinal direction of the rotor blade between a root end and a tip end, wherein a cross section of the rotor blade between the leading edge and the trailing edge defines a profile chord, the method comprising:
mounting a plurality of serrations in a region of the trailing edge of the rotor blade, wherein each serration of the plurality of serrations has a base line, which is arranged at the trailing edge, and an end point, located furthest away from the base line, which together span a plane of the serration,
wherein a serration of the plurality of serrations is a tooth of a trailing edge ridge of the rotor blade,
wherein an angle between the plane of at least one serration of the plurality of serrations and the profile ch

Assignees

• Wobben Properties Gmbh

Inventors

• Messing Ralf
• Stemberg Jochen

Classifications

• F05B2250/411

  in rotation · CPC title

• F05B2240/2211

  of the multibladed, low speed, e.g. "American farm" type · CPC title

• F05B2240/3042

  Serrated trailing edge · CPC title

• F05B2240/3052

  adjustable · CPC title

• F05B2270/32

  Wind speeds · CPC title