WIND TURBINE ROTOR BLADE

Description

[0001] The present invention relates to a wind turbine rotor blade.

[0002] Since the rotor blades of a wind turbine are exposed to all weather conditions without protection, they can ice up at certain temperatures. To prevent this, rotor blade heating can be used. This can either be installed on the outside of the rotor blade or heated air can be directed into the rotor blade.

[0003] To prevent icing on rotor blades, rotor blade heating is often used. Typically, heated air is introduced into the interior of the rotor blade near the root of the rotor blade. This heated air, in turn, heats the rotor blade shell, for example, near the leading edge, thus de-icing the rotor blade.

[0004] EP 3 450 751 A1 shows a wind turbine rotor blade with a rotor blade heater.

[0005] WO 2017 / 021350 A1 shows a wind turbine rotor blade with a rotor blade root region and a rotor blade tip region, as well as a rotor blade heater. Furthermore, at least one web is provided along a longitudinal direction of the rotor blade. A deflection unit for deflecting the air can be provided on the web.

[0006] WO 2018 / 211055 shows a rotor blade of a wind turbine, which has a web and a deflection unit at the rotor blade tip for deflecting heated air.

[0007] Therefore, an object of the present invention is to provide a wind turbine rotor blade with improved rotor blade heating.

[0008] This object is achieved by a wind turbine rotor blade according to claim 1.

[0009] Thus, a wind turbine rotor blade is provided with a rotor blade shell surrounding an interior volume and having at least one vortex generator within the interior volume. By providing the vortex generators within the interior volume (e.g., on the inside of the rotor blade shell), the airflow inside the rotor blade shell can be improved, leading to improved heat transfer and thus better heating of the rotor blades.

[0010] According to the invention, first vortex generators are provided on an inner side of the rotor blade shell.

[0011] According to the present invention, the rotor blade has at least one web along a longitudinal direction of the rotor blade. According to the invention, second vortex generators are arranged on the at least one web or are attached to the web.

[0012] According to a further aspect of the present invention, the rotor blade has at least a first and a second web along a longitudinal direction of the rotor blade. Furthermore, a first air duct is provided between a leading edge of the rotor blade and a first web, wherein at least one vortex generator is provided in the first air duct.

[0013] According to a further aspect of the present invention, the rotor blade has a second air duct between a web and a rotor blade trailing edge. At least one vortex generator is provided at least partially in the second air duct along the longitudinal direction of the rotor blade.

[0014] According to a further aspect of the present invention, the rotor blade has at least one vortex generator in a third air channel between the first and second webs.

[0015] According to a further aspect of the present invention, the rotor blade includes a rotor blade heating system in or at the root of the rotor blade. The rotor blade heating system generates warm air, which is conveyed into the interior volume of the rotor blade.

[0016] The invention also relates to a wind turbine with at least one wind turbine rotor blade as described above.

[0017] By installing vortex generators on the inside of the rotor blade shell and on the web(s), the heat transfer of the heated air to the rotor blade shell can be improved. Due to the geometry of the vortex generators, locating them inside the rotor blade does not result in significant pressure loss. This is achieved because the wall pressure loss depends primarily on the normal gradient of the velocity component along the main flow direction at the wall and not on the gradient of the velocity component of the secondary flow.

[0018] Thus, a wind turbine rotor blade is provided with a (two-part) blade shell that surrounds an interior volume. The rotor blade further comprises a rotor blade root and a rotor blade tip. At least one web is provided between the two blade shells along a longitudinal direction of the rotor blade, so that the interior volume of the rotor blade is divided into at least two sections. The rotor blade further comprises a rotor blade heater, which is provided, for example, in the region of the rotor blade root and conveys heated air into the interior volume of the rotor blade. To improve the effectiveness of the blade heater, at least one first vortex generator is provided in the interior volume. At least one second vortex generator is provided on the at least one web.The more uniform mixing of the flow caused by the vortex generators leads to improved heat transfer to the rotor blade shells, so that improved rotor blade heating can be achieved by providing the vortex generators.

[0019] A web is provided between the two blade shells (pressure side, suction side), creating an air channel in the area of ​​the rotor blade's leading edge through which the air heated by the rotor blade heater can flow. At least one third vortex generator is provided in the area of ​​the first channel, at least partially along a longitudinal axis of the rotor blade.

[0020] According to a further aspect of the present invention, a second web is provided between the two rotor blade shells, creating a second channel in the region of the rotor blade trailing edge. An optional fourth vortex generator can be provided in this second channel.

[0021] According to one aspect of the present invention, a third channel may be provided at least partially between the first and second webs. Optionally, fifth vortex generators may be provided in the third channel.

[0022] According to the invention, by providing vortex generators in the interior volume of the rotor blade, the flow is mixed, resulting in a more uniform temperature distribution. This results in an increase in the heat transfer coefficient α. In addition to the vortex generators, cross-sectional constrictions can be provided inside the rotor blades. According to the invention, the internal blade flow is modified to improve heat transfer of the heated air from the blade heater to the rotor blade shell. The cross-sectional constrictions represent passive ways of increasing the flow velocity.

[0023] According to one aspect of the invention, the vortex generators and the cross-sectional constrictions can be installed subsequently.

[0024] Further embodiments of the invention are the subject of the subclaims.

[0025] Advantages and embodiments of the invention are explained in more detail below with reference to the drawing. Fig. 1 shows a schematic representation of a wind turbine according to the invention, Fig. 2A shows a schematic cross-section and a schematic and 2B longitudinal section of a rotor blade according to the prior art, Fig. 3A shows a schematic cross-section of a rotor blade according to one aspect of the invention, and Fig. 3B shows a schematic longitudinal section of a rotor blade according to Fig. 3A .

[0026] Fig. 1 shows a schematic representation of a wind turbine according to the invention. The wind turbine 100 has a tower 102 and a nacelle 104 on the tower 102. An aerodynamic rotor 106 with three rotor blades 200 and a spinner 110 is provided on the nacelle 104. During operation of the wind turbine, the aerodynamic rotor 106 is set in rotation by the wind and thus also rotates a rotor or rotor of a generator, which is directly or indirectly coupled to the aerodynamic rotor 106. The electrical generator is arranged in the nacelle 104 and generates electrical energy. The pitch angles of the rotor blades 200 can be changed by pitch motors at the rotor blade roots of the respective rotor blades 200.

[0027] For rotor blade de-icing, a rotor blade heater 500 can be provided in the area of ​​a rotor blade root. Alternatively, the rotor blade heater 500 can be provided in the area of ​​a rotor hub or at a rotor blade connection. The rotor blade heater 500 generates warm air and then directs it into the interior of the rotor blade to de-ice the rotor blade or to prevent icing.

[0028] Fig. 2A shows a cross-section of a rotor blade and Fig. 2B shows a longitudinal section of a rotor blade. The rotor blade 200 has two blade shells 210, 220, each with an inner side 211, 221, which surround an internal volume 203. The rotor blade 200 further has a rotor blade leading edge 230 and a rotor blade trailing edge 240. Webs 231, 232 can be provided between the blade shells 210, 220, so that the internal volume 203 can be divided into different sections or channels 250, 260, and 270 (first channel 250 between leading edge 230 and first web 231, second channel 260 between trailing edge 240 and second web 232, and third channel 270 between first and second webs 231, 232). The web 231 can, for example, be longer than the web 232.

[0029] Optionally, deflection bends 600 can be provided at the free end of the webs. According to one aspect of the present invention, vortex generators can be provided in or on the deflection bend.

[0030] At least one vortex generator 400 can be provided inside the rotor blade, i.e., on the inside of the rotor blade shells and / or on the webs 231, 232. The vortex generator 400 can be placed throughout the entire interior volume of the rotor blade. For example, the vortex generators 400 can be placed in the first, second, or third channel 250, 260, 270 on the insides 211, 221 of the rotor blade shells 210, 220 and / or on the webs 231, 232. By providing the vortex generators 400, the air flow inside the rotor blade can be positively influenced. In particular, turbulence can be generated. This can improve heat transfer from the heated air, which is generated by the rotor blade heater 500, to the rotor blade shells.

[0031] Several vortex generators 400 can be provided along the length of the rotor blade 200.

[0032] Fig. 3A und 3B show a corresponding cross-section of a rotor blade and a longitudinal section of the rotor blade according to an embodiment of the invention. While in the rotor blade according to Fig. 2A und 2B Channels 250, 260 and 270 with the vortex generators 400 are shown unchanged, in the channels according to Fig. 3A und 3B At least partially, cross-sectional constrictions 310 are provided in the first channel 250, second cross-sectional constrictions 320 in the second channel 260, and / or optionally third cross-sectional constrictions 330 in the third channel 270. In addition to the vortex generators 400, cross-sectional constrictions 300 can thus be provided.

[0033] In Fig. 3B the distribution of the cross-sectional constrictions 310, 320, 330 along a longitudinal axis of the rotor blade is shown.

[0034] Both the cross-sections of the cross-sectional constrictions and their distribution along the longitudinal axis of the rotor blade can be determined according to the invention from the Fig. 3A und 3B shown cross-sections and longitudinal distributions.

[0035] The cross-sectional constrictions result in a higher flow velocity of the air flowing through the rotor blade heater 500 into the interior (into the channels 250, 260, 270) of the rotor blade.

[0036] The cross-sectional constrictions in combination with the vortex generators can contribute to improving rotor blade heating. Bezugszeichenliste

[0037] 100 Wind turbine 102 Tower 104 Nacelle 106 Rotor 110 Spinner 200 Rotor blades 203 Internal volume 210 Blade shells 211 Blade shell interior 220 Blade shells 221 Blade shell interior 230 Rotor blade leading edge 231 Webs 232 Webs 240 Rotor blade trailing edge 250 Channels 260 Channels 270 Channels 300 Cross-section constriction 310 Cross-section constrictions 320 Cross-section constrictions 330 Cross-section constrictions 400 Vortex generator 500 Rotor blade heater

Claims

1. A wind turbine rotor blade (200), with a rotor blade shell (210, 220), which envelops an internal volume (203), and at least one vortex generator (400) in the internal volume (203), wherein first vortex generators (400) are arranged on an interior side (211, 221) of the rotor blade shell (210, 220), and protrude into the internal volume (203), further with at least one web (231, 232) in the internal volume (203) along a longitudinal direction (L) of the rotor blade (200), wherein second vortex generators (400) are arranged on the at least one web (231, 232).

2. The wind turbine rotor blade (200) according to claim 1, with at least one first and second web (231, 232) in the internal volume (203) along a longitudinal axis (L) of the rotor blade (200), and a first air channel (250) between a leading edge (230) of the rotor blade (200) and a first web (231), wherein at least one third vortex generator (400) is provided in the first air channel (250).

3. The wind turbine rotor blade (200) according to claim 2, with a second air channel (260) between a web (231, 232) and a rotor blade trialing edge (240), wherein at least one fourth vortex generator (400) is provided at least partially in the second air channel (260) along the longitudinal direction (L) of the rotor blade (200).

4. The wind turbine rotor blade (200) according to claim 3, with at least one fifth vortex generator (400) in a third ventilation channel (270) between the first and second webs (231, 232).

5. The wind turbine rotor blade (200) according to one of claims 1 to 4, further with a rotor blade heating system (500) in or on a rotor blade root (201) of the wind turbine rotor blade (200), wherein the rotor blade heating system (500) generates heated air, and conveys it into the internal volume (203) of the rotor blade (200).

6. The wind turbine rotor blade (200) according to one of claims 1 to 5, further with at least one cross sectional constriction (300, 310, 320, 330) for narrowing a free cross section of the internal volume (203).

7. A wind turbine (100) with at least one wind turbine rotor blade (200) according to claims 1 to 6.

8. A wind turbine (100) according to claim 7, further with: a rotor blade heating system (500) for generating heated air, which is conveyed into the internal volume (203) of the rotor blade (200).