METHOD FOR REDUCING THE NOISE EMISSION OF A WIND TURBINE ROTOR BLADE AND WIND TURBINE ROTOR BLADE

Description

[0001] The present invention relates to a method for reducing the noise emission of a wind turbine rotor blade and wind turbine rotor blade.

[0002] To reduce the noise emission of a wind turbine rotor blade during operation, an attachment such as a trailing edge serration can be fitted or glued to the trailing edge of a rotor blade.

[0003] During the patent granting procedure, the following documents were considered, among others: EP 3 129 645 B1 and WO 2020 / 231828 A1.

[0004] The object of the present invention is to further reduce the noise emission of a wind turbine rotor blade during operation.

[0005] This problem is solved by a method for reducing the noise emission of a wind turbine rotor blade according to claim 1 and by a wind turbine rotor blade according to claim 7.

[0006] This describes a method for reducing the noise emission of a wind turbine rotor blade during operation. The rotor blade has a root, a tip, a leading edge, a trailing edge, a suction side, and a pressure side. An attachment or component may be provided on the pressure side and, in particular, on the trailing edge. At least one trailing edge ridge with multiple teeth is provided on the trailing edge.

[0007] Furthermore, there is a first transition between the suction side and the attachment, as well as a second transition between the pressure side and the attachment. The transition between the pressure side and the attachment is filled with a leveling compound. The attachment is designed as a trailing-edge comb.

[0008] According to one aspect of the present invention, a spatula is applied to a surface of the pressure side and covers the pressure-side (second) transition, and in particular any step at the pressure-side (second) transition. The point on a pressure side of the attachment (i.e., the trailing edge ridge) where the free end of the spatula rests is marked and defines the area to which the leveling compound is to be applied. Thus, the leveling compound can be provided in such a way that it allows for an extension of the pressure-side surface without a transition or step.

[0009] According to one aspect of the present invention, a first adhesive tape can be provided at the transition between the suction side and the attachment part (i.e., a trailing edge comb).

[0010] Furthermore, a second adhesive tape can be applied to the surface of the printed side adjacent to the transition. A third adhesive tape can be applied in the area of ​​the marking. A leveling compound can be applied between the second and third adhesive tapes.

[0011] According to another aspect, a leveling material, for example in the form of a bead of adhesive, can be applied in the transition area. The material can then be spread using a spatula. Afterwards, all adhesive tapes can be removed, resulting in a rotor blade with a transition between the pressure side and an attachment (i.e., a trailing edge comb) that has been leveled with a leveling material, thus creating an extension of the pressure side surface in the area of ​​the leveling material.

[0012] The pressure-side (secondary) transition can take the form of an edge, step, depression, recess, or notch. Applying the leveling compound smooths out the pressure-side (secondary) transition. . Such a transition can take place

[0013] This can have a negative impact in a frequency range above 800 Hz. This can cause the permitted noise level to be exceeded.

[0014] According to the invention, the attachment is a trailing edge comb.

[0015] According to one aspect of the present invention, a wind turbine rotor blade is provided with a leading edge, a trailing edge, a suction side, a pressure side, and an attachment at least partially on the pressure side. A pressure-side transition between the pressure side and the attachment is present and is leveled by applying a compensating compound.

[0016] According to one aspect of the present invention, a recess or projection is provided in the area of ​​the pressure-side transition and the compensating compound is applied in the area of ​​the pressure-side transition and in the area of ​​the recess or step.

[0017] Further embodiments of the invention are the subject of the dependent claims.

[0018] The 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 one aspect of the present invention, Fig. 2 shows a cross-section of a rotor blade according to one aspect of the present invention, Figs. 3 to 8 each show a schematic cross-section of a rotor blade of a wind turbine when a compensating material is applied to a pressure side of the rotor blade according to one aspect of the present invention, and Fig. 9 shows a schematic cross-section of a rotor blade according to an embodiment not according to the invention.

[0019] Fig. 1Figure 1 shows a schematic representation of a wind turbine according to one aspect of the present 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 into rotation by the wind and thus also rotates a rotor or runner of a generator, which is directly or indirectly coupled to the aerodynamic rotor 106. The electric 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 210 of the respective rotor blades 200.

[0020] The rotor blade 200 has a rotor blade root 210, a rotor blade tip 220, a rotor blade leading edge 230, a rotor blade trailing edge 240, a suction side 250, and a pressure side 260. At least partially, an attachment 300 in the form of a trailing edge crest 300 with a plurality of teeth 320 is provided on the trailing edge 240. .

[0021] The attachment part 300 can also be provided not on the rear edge 240, but at least partially on the pressure side 260.

[0022] Fig. 2 Figure 1 shows a cross-sectional view of a rotor blade according to one aspect of the present invention. The rotor blade of Fig. 2 can according to a rotor blade Fig. 1 A component 300 in the form of a trailing edge comb 300 is attached to the trailing edge 240 of the rotor blade 200. .A first (suction-side) transition 241 between the suction side 250 and the attachment 300 (i.e., a trailing edge ridge) and a second (pressure-side) transition 242 between a pressure side 260 and the attachment 300 (i.e., a trailing edge ridge) can be provided. The second transition 242 can have a recess 263 or a projection 263. This results, for example, in the thickness of the trailing edge 240 decreasing or increasing (abruptly) in the direction of the trailing edge.

[0023] During the investigation of a rotor blade according to the invention, it was found that the pressure-side (second) transition on the pressure side has an unexpectedly negative effect on the noise emission of the rotor blade during operation. Previously, it had been assumed that only such a transition on the suction side had a negative effect on noise emission.

[0024] According to one aspect of the invention, the printed side 200 has a surface 261 which can be substantially straight in the region of the trailing edge 240. In the region of the second transition 242, a step or a step 262 can be provided, which is to be compensated for by a compensating mass 400.

[0025] According to the invention, a compensating mass is provided in the area of ​​the second transition between the pressure side and the trailing edge crest in order to compensate for this second transition. This leads to a significant reduction in the noise emissions generated during the operation of the rotor blade.

[0026] The second transition 242 may optionally have a stepback or a recess 262 with a step 263 and a length 264.

[0027] Figs. 3 to 8Figure 1 shows a schematic cross-section of a rotor blade of a wind turbine after the application of a compensating material to a pressure side of the rotor blade according to one aspect of the present invention. The rotor blade 200 has a suction side 250, a pressure side 260, a trailing edge 240, and an attachment in the form of a trailing edge ridge 300. The pressure side 260 has a surface 261, which can be substantially straight in the region of the trailing edge 240. A first suction-side transition 241 can be provided between the suction side 250 and the trailing edge ridge 300, and a second pressure-side transition 242 can be provided between the pressure side 260 and the trailing edge ridge 300. In the region of the second transition 242, a recess 262 in the material of the rotor blade can be provided in the region of the trailing edge 240, which is to be compensated for by a compensating mass. The second transition 242 can have a recess orThe rotor blade material has a recess 262 with a step 263 and a length 264. To compensate for the step-back or in the transition 262, a spatula 700 with a first straight end 710 can be provided. The spatula 700 can be positioned in the area of ​​the second transition 242 such that the end 210 rests against a surface 261 of the pressure side as well as against a pressure side of the trailing edge crest. As in . Fig. 3 As can be seen in the cross-section, the area to be leveled is limited by the recess 262 and the end 710 of the spatula 700. Optionally, the point of contact between the end 710 and the pressure side of the trailing edge comb can be marked with a 321. This allows the point to be defined up to which the leveling compound 400 should be applied. This is intended to level the transition between the pressure side 260 and the trailing edge comb 300.

[0028] This can be done, for example, as in Fig. 4 A first adhesive tape 810 is to be seen in the area of ​​the first transition 241 between the suction side 250 and the trailing edge ridge 300.

[0029] As in Fig. 5 As can be seen, a second adhesive tape 820 may be provided on the printed side 260 adjacent to the second transition 242. A third adhesive tape 830 may be provided in the area of ​​the marking 321.

[0030] Then, as in Fig. 6 The illustration shows that a leveling material 400 can be applied, for example, in the form of an adhesive bead. The material 400 can then be applied and spread between the adhesive tapes 820 and 830, for example, using a spatula 700.

[0031] In Fig. 8 The final result can then be seen. Here, the surface of the compensating material is adapted to the surface 261 of the pressure side 260 of the rotor blade in the area of ​​the trailing edge.

[0032] The second transition 242 has been compensated for by the balancing mass.

[0033] Fig. 9 Figure 1 shows a schematic cross-section of a rotor blade according to an embodiment, not according to the invention. The rotor blade according to Fig. 9 can thereby according to the rotor blade Fig. 2 correspond. The rotor blade 200 has a suction side 250 and a pressure side 260 with a surface 261. The rotor blade 200 also has a trailing edge 240. In the area of ​​the trailing edge 240, an attachment 300, for example in the form of a trailing edge crest 300, can be provided. While according to the exemplary embodiment of Fig. 2 If a recess is present in the area of ​​the pressure side 260 of the rotor blade, such a recess is not present in the rotor blade according to Fig. 9A first suction-side transition 241 is provided in the area of ​​the suction side 250 and the attachment 300. A second pressure-side transition is provided between the pressure side 260 and the attachment 300. According to the embodiment of Fig. 9 The attachment 300 has a first end 310 with a first, second, and third section 311, 312, 313. The second and third sections 312, 313 extend at least partially along the surface 261 of the pressure side 260. Thus, a step or projection 313 is present in the area of ​​the second pressure-side transition 242 between the pressure side 260 and the attachment 300. This projection 313 negatively affects the aerodynamic properties of the rotor blade 200 and, in particular, the acoustic properties of the rotor blade. Therefore, analogous to the embodiment of Figs. 3 to 8A compensating mass 400 is provided in the area of ​​the second pressure-side transition 242 in order to obtain a more aerodynamically favorable transition.

[0034] According to the invention, the attachment 300 is a trailing edge comb. The key feature here is that a recess (as in Fig. 3 ) or an advantage (as in Fig. 9 ) is present on the pressure side, resulting in an aerodynamically unfavorable transition.

[0035] According to one aspect of the present invention, the aerodynamically unfavorable transition is treated by means of a compensating mass 400 in order to obtain an aerodynamically more favorable transition. Reference symbol list

[0036] 100 Wind turbine 102 Tower 104 Nacelle 106 Aerodynamic rotor 110 Spinner 200 Rotor blades 200b Rotor blade roots 210 Rotor blade root 220 Rotor blade tip 230 Rotor blade leading edge 240 Rotor blade trailing edge 241 First transition 242 Second transition 250 Suction side 260 Pressure side 261 Surface 262 Backset 263 Step 264 Compensation length 300 Attachment 310 First end 311 First section 312 Second section 313 Third section 320 Teeth 321 Mark 400 Adhesive / Compensation 700 Spatula 710 First end 810 First adhesive tape 820 Second adhesive tape 830 Third adhesive tape

Claims

1. A method for reducing a noise emission of a wind turbine rotor blade (200), wherein the wind turbine rotor blade has a leading edge (230), a trailing edge (240), a suction side (250), a pressure side (260) and an attachment part (300) as a trailing edge comb on the trailing edge (240), wherein a pressure-side transition (242) is present between the pressure side (260) and the attachment part (300), with the following step: leveling the pressure-side transition (242) by applying a leveling compound (400), wherein a recess in the form of a step (262), a sink or a cut out is present in the area of the pressure-side transition (242) in a material of the rotor blade (200) on the pressure side (260) of the trailing edge (240), wherein the recess (262) is levelled with levelling material (400).

2. The method according to claim 1, wherein the attachment part (300) is configured as a trailing edge comb (300), wherein a suction-side transition (241) is present between the suction side (250) and the trailing edge comb (300).

3. The method according to claim 2, wherein, in order to level the pressure-side transition (242), a spatula (700) is applied against a surface (261) of the pressure side (260), and covers the pressure-side transition (242) in such a way that an area (321) on one pressure side (260) of the trailing edge comb (300) against which the free end of the spatula (700) abuts represents an area up to which the leveling compound (400) is to be applied.

4. The method according to claim 1, wherein a first adhesive tape (810) is provided on the pressure-side transition between the suction side and the trailing edge comb (300), wherein a second adhesive tape (820) is provided on the surface (261) of the pressure side (260) adjacent to the second transition (242), and wherein a third adhesive tape (30) is provided in the leveling compound area.

5. The method according to claim 1 to 3, wherein a leveling material (400) is applied in the area of the pressure-side transition (242), and distributed by means of a spatula (700).

6. The method according to claim 1 or 2, wherein the attachment part (300) is at least partially arranged on the pressure side (260), wherein the attachment part (300) has a first end (310), wherein a protrusion or a step (313) is present in the area of the pressure-side transition (242) between the pressure side (260) and the first end (310) of the attachment part (300), wherein the leveling compound (400) is applied in the area of the pressure-side transition (242).

7. A wind turbine rotor blade (200), with a leading edge (230), a trailing edge (240), a suction side (250), a pressure side (260), and an attachment part (300) as trailing edge comb on the trailing edge (240), wherein a pressure-side transition (242) is present between the pressure side (260) and the attachment part (300), wherein a leveling compound (400) is present in the area of the pressure-side transition (242), wherein, in the area of the pressure-side transition (242), a recess in a material of the rotor blade (200) is present on the pressure side (260) of the trailing edge (240), and leveled by the leveling compound (400), wherein the recess (262) is levelled with levelling material (400).

8. The wind turbine rotor blade (200) according to claim 7, wherein in the area of the pressure-side transition (242), a protrusion or a step is present between the pressure side (260) and a first end (310) of the attachment part (300), wherein the leveling compound is applied in the area of the pressure-side transition.