Wind turbine blade and wind turbine

Abstract

A wind turbine blade of a wind turbine, the wind turbine blade including a shell and a spar having at least one spar cap is provided. At least one of the at least one spar cap includes at least two longitudinal support structure elements, whereby at least two of the at least two longitudinal support structure elements are arranged adjacent to one another in a longitudinal direction of the wind turbine blade and at least one longitudinal support structure includes carbon fiber-reinforced plastic and at least one other longitudinal support structure includes at least one fiber-reinforced plastic different from carbon fiber-reinforced plastic.

Claims

1. A wind turbine blade of a wind turbine, the wind turbine blade comprising: a shell; and a spar having at least one spar cap, wherein at least one of the at least one spar cap comprises at least two adjacent longitudinal support structure elements, whereby one of the at least two longitudinal support structure elements is arranged in a space formed in an adjacent support structure element to merge the at least two longitudinal support structure elements together such that the at least two longitudinal support structures themselves form a structural joint therebetween so that the at least two longitudinal support structures are connected to one another in a longitudinal direction of the wind turbine blade, and at least one longitudinal support structure comprises carbon fiber-reinforced plastic and at least one other longitudinal support structure comprises at least one fiber-reinforced plastic different from carbon fiber-reinforced plastic.

2. The wind turbine blade according to claim 1, wherein at least one of the at least one longitudinal support structure comprising carbon fiber-reinforced plastic is predominantly comprising carbon fiber-reinforced plastic as fiber-reinforced plastic and at least one of the at least one other longitudinal support structure comprising at least one fiber-reinforced plastic different from carbon fiber-reinforced plastic is predominantly comprising fiber-reinforced plastics different from carbon fiber-reinforced plastic as fiber-reinforced plastic.

3. The wind turbine blade according to claim 1, wherein the structural joint is resin molded.

4. The wind turbine blade according to claim 1, wherein the at least two adjacent longitudinal support structure elements are arranged at an arrangement angle of 0.5° ≤α≤10° with respect to each other.

5. The wind turbine blade according to claim 1, wherein the at least one fiber-reinforced plastic comprises at least one unidirectional glass mat and/or the carbon fiber-reinforced plastic comprises at least one pultruded carbon fiber element.

6. The wind turbine blade according to claim 1, wherein a length of at least two of the at least two adjacent longitudinal support structure elements is different from one another.

7. The wind turbine blade according to claim 1, wherein the at least one longitudinal support structure comprising carbon fiber-reinforced plastic terminates at least 5 m from a tip of the wind turbine blade.

8. The wind turbine blade according to claim 1, wherein at least one end portion of at least one of the at least two adjacent longitudinal support structure elements is tapered in a longitudinal direction and/or with a tapering angle of 0.2° ≤β≤5° .

9. The wind turbine comprising at least two wind turbine blades according to claim 1.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

(2) FIG. 1 depicts a sectional view along a transversal plane of a first embodiment of a wind turbine blade;

(3) FIG. 2 depicts a projected view along a shell plane of the first embodiment of the wind turbine blade with spar caps elements highlighted;

(4) FIG. 3 depicts an exploded sectional view along a transversal plane of a support structure along line of FIG. 2;

(5) FIG. 4 depicts an exploded sectional view along the transversal plane of a support structure along line IV-IV of FIG. 2;

(6) FIG. 5 depicts an exploded sectional view along a longitudinal plane of a structural joint along line V-V of FIG. 2;

(7) FIG. 6 depicts a projected view along the shell plane of a second embodiment of the wind turbine blade with spar caps elements;

(8) FIG. 7 depicts a projected view along the shell plane of a third embodiment of the wind turbine blade with spar caps elements;

(9) FIG. 8 depicts a projected view along the shell plane of a fourth embodiment of the wind turbine blade with spar caps elements; and

(10) FIG. 9 depicts a wind turbine comprising wind turbine blades.

(11) Same aspects in FIGS. 1 to 9 are denominated with the same reference number. If there is more than one aspect of the same kind in one of the figures, the asoects are numbered in ascending order with the ascending number of the aspects being separated from its reference number by a dot.

DETAILED DESCRIPTION

(12) FIG. 1 is a sectional view along a transversal plane of a first embodiment of a wind turbine blade 10 according to the embodiment of the present invention. The transversal plane is transverse, in particular perpendicular, to a longitudinal axis L.sub.10 of the wind turbine blade 10, which is indicated in FIG. 2. The wind turbine blade 10 has a trailing edge 11 and a leading edge 12. The wind turbine blade 10 comprises a shell 20 and a spar 30. The spar 30 comprises two spar caps 40.1, 40.2, which face each other and are connected to one another by means of a spar web 50.

(13) FIG. 2 is a sectional view along a shell plane of the first embodiment of the wind turbine blade 10 of FIG. 1. The shell plane is a plane running through the upper part of the curved shell 20 and the spar cap 40.1, which is transverse, in particular perpendicular, to the transversal plane. The spar cap 40.1 of the wind turbine blade 10 comprises three longitudinal support structure elements 41.1, 41.2, 41.3. The first and third longitudinal support structure elements 41.1, 41.3 are made from glass fiber-reinforced plastic and the second longitudinal support structure 41.2 is made from carbon fiber-reinforced plastic.

(14) The first longitudinal support structure 41.1 is arranged at a root or at a distance of about 2 m from the root of the wind turbine blade 10 and its length X.sub.41.1 is 20% of the length X.sub.10 of the wind turbine blade 10 in this particular embodiment. The length X.sub.10 of the wind turbine blade 10 is measured along the longitudinal axis L.sub.10 from the root to the tip of the wind turbine blade 10. The first longitudinal support structure 41.1 may have a length X.sub.41.1 of 10% to 30% of the length X.sub.10 of the wind turbine blade 10, for example. The first support structure 41.1 enables a smooth stiffness increase of the spar cap 40.1 in a direction from the root to the tip of the wind turbine blade 10. Moreover, glass fiber-reinforced plastic is more cost-effective than carbon fiber-reinforced plastic and close to the root of the wind turbine blade a stiffness as high as the one of carbon fiber-reinforced plastic is typically not necessary.

(15) The second longitudinal support structure 41.2 is arranged in a middle portion of the wind turbine blade 10 and is arranged in between the first support structure 41.1 and the third support structure 41.3. The length X.sub.41.2 of the second support structure is 50% of the length X.sub.10 of the wind turbine blade 10 in this particular embodiment. The second longitudinal support structure 41.1 may have a length X.sub.41.2 of 30% to 80% of the length X.sub.10 of the wind turbine blade 10, for example. The first longitudinal support structure 41.1 enables an overall increase of the stiffness of the spar cap 40.1 of the wind turbine blade 10 by containing its mass.

(16) The third longitudinal support structure 41.3 is arranged at the root or at a distance of 5 m from the root of the wind turbine blade 10 and is arranged adjacent to the second longitudinal support structure 41.2. The length X.sub.41.3 of the third longitudinal support structure 41.3 is 30% of the length X.sub.10 of the wind turbine blade 10 in this particular embodiment. The third longitudinal support structure 41.1 may have a length X.sub.41.3 of 10% to 40% of the length X.sub.10 of the wind turbine blade 10, for example. The third longitudinal support structure 41.3 prevents the second longitudinal support structure 41.2 made from carbon fiber-reinforced plastic from being damaged when the tip of the wind turbine blade 10 is being struck by a lightning.

(17) The first longitudinal support structure 41.1 and the second support structure 41.2 are connected to each other by means of a first structural joint 42.1 having a length X.sub.42.1 in which the first longitudinal support structure 41.1 and the second longitudinal support structure 41.2 overlap each other. Further, the second longitudinal support structure 41.2 and the third longitudinal support structure 41.3 are connected to each other by means of a second structural joint 42.2 having a length X.sub.42.2 in which the second longitudinal support structure 41.2 and the third longitudinal support structure 41.3 overlap each other. The longitudinal support structure elements 41.1, 41.2, 42.3 are securely connected to one another by means of the structural joints 42.1, 42.2, which are resin molded in this particular embodiment.

(18) The second longitudinal support structure 41.2 is arranged with respect to the third support structure 41.3 at an arrangement angle of α=5° formed between the longitudinal axis of the second longitudinal support structure 41.2, which is coinciding with the longitudinal axis L.sub.10 of the wind turbine blade 10 in this particular embodiment, and the longitudinal axis L.sub.41.3 of the third longitudinal support structure 41.3. Thereby, a tip sweep S, a distance of the tip from the longitudinal axis L.sub.10 of the wind turbine blade 10, is formed.

(19) FIG. 3 is an exploded sectional view along a transversal plane of the first longitudinal support structure 41.1 along line of FIG. 2. The transversal plane is transverse, in particular perpendicular, to a longitudinal axis of the first longitudinal support structure 41.1, which is coinciding with the longitudinal axis L.sub.10 of the wind turbine blade 10 in this particular embodiment. Two different types of glass mats 60, 61 are being used for the first longitudinal support structure 41.1 in this embodiment, which are arranged as alternating layers of the first type of glass mat 60.1, 60.2, 60.3, 60.4, 60.5, 60.5 and second type of glass mat 61.1, 61.2, 61.3, 61.4 having a width W.sub.60 and a thickness T.sub.60. The width W.sub.60 may be in the range of 400 mm to 1200 mm. The thickness T.sub.60 may be in the range of 0.1 mm to 2.0 mm. The first type of glass mat 60.1, 60.2, 60.3, 60.4, 60.5, 60.5 may be a biax non-crimp fabric. The second type of glass mat 61.1, 61.2, 61.3, 61.4 may be unidirectional glass mat.

(20) FIG. 4 is an exploded sectional view along a transversal plane of the second longitudinal support structure 41.2 along line IV-IV of FIG. 2. The transversal plane is transverse, in particular perpendicular, to a longitudinal axis of the second longitudinal support structure 41.2, which is coinciding with the longitudinal axis L.sub.10 of the wind turbine blade 10 in this particular embodiment. Pultruded carbon fiber elements 70.1, 70.2, 70.3, 70.4, 70.5, 70.6 are provided in the second longitudinal support structure 41.2. In particular, a first stack with stacked carbon fiber elements 70.1, 70.2, 70.3 and a second stack with stacked carbon fiber elements 70.4, 70.5, 70.6 are provided adjacent to each other in the longitudinal direction of the second longitudinal support structure 41.2. The carbon fiber elements have a width of W.sub.70, which may be in the range of 50 mm to 300 mm. The thickness of the carbon fiber elements can be i.e. in the range of 2-5 mm. A first wedge element 72.1 is arranged next to the first stack comprising the carbon fiber elements 70.1, 70.2, 70.3 forming an outer long side of the second longitudinal support structure 41.2. A second wedge element 72.2 is arranged next to the second stack comprising the carbon fiber elements 70.4, 70.5, 70.6 forming another outer long side of the second longitudinal support structure 41.2. The wedge elements 72.1, 72.2 may comprise or be made from basalt, balsa, a foam or glass, for example. A cover mat 71 is surrounding the carbon fiber elements 70.1, 70.2, 70.3, 70.4, 70.5, 70.6 and the wedge elements 72.1, 72.2. The cover mat 71 may comprise multiple cover mats or parts thereof. The cover mats may comprise or be made from carbon, glass, basalt or a hybrid combination thereof, for example.

(21) FIG. 5 is an exploded sectional view along a longitudinal plane of the structural joint 42.2 along line V-V of FIG. 2. The carbon fiber elements 70.1, 70.2, 70.3 of the second longitudinal support structure 41.2 are surrounded by cover mats 71.1, 71.2, 71.3, 71.4, 71.5, 71.6, 71.7, 71.8 and the carbon fiber elements 70.1, 70.2, 70.3 and cover mats 71.1, 71.2, 71.3, 71.4, 71.5, 71.6, 71.7, 71.8 are merged into the third support structure 41.3 having multiple layers of glass mat 60, 61, only the glass mats 60.1 and 61.1 of which are denominated. Also, the glass mats 60.1 and 61.1 of the third longitudinal support structure 41.3 are arranged in spaces between the carbon fiber elements 70.1, 70.3 and cover mats 71.1, 71.2, 71.3, 71.6, 71.7, 71.8 so that the third longitudinal support structure 41.3 is merged into the second longitudinal support structure 41.2. The structural joint 42.2 is resin molded, the resin covering the entire structural joint 42.2 and not being shown. The second longitudinal support structure 41.2, in particular each of the carbon fiber elements 70.1, 70.2, 70.3, is tapered in its longitudinal direction with a tapering angle of β=0.3° in this particular embodiment.

(22) FIG. 6 is a sectional view along a shell plane of a second embodiment of the wind turbine blade 10 according to the embodiment of the present invention. The spar cap 40.1 of the wind turbine blade 10 comprises two longitudinal support structure elements 41.1, 41.2. The first longitudinal support structure 41.1 is made from carbon fiber-reinforced plastic and the second longitudinal support structure 41.2 is made from glass fiber-reinforced plastic. The first longitudinal support structure 41.1 and the second longitudinal support structure 41.2 are arranged at an arrangement angle of α=5° with respect to each other and are connected to each other by means of a structural joint 42.1. The first longitudinal support structure 41.1 has a greater length than the length of the second longitudinal support structure 41.2.

(23) FIG. 7 is a sectional view along a shell plane of a third embodiment of the wind turbine blade 10 according to the embodiment of the present invention. The spar cap 40.1 of the wind turbine blade 10 comprises two longitudinal support structure elements 41.1, 41.2. The first longitudinal support structure 41.1 is made from glass fiber-reinforced plastic and the second longitudinal support structure 41.2 is made from carbon fiber-reinforced plastic. The first longitudinal support structure 41.1 and the second longitudinal support structure 41.2 are connected to each other by means of a structural joint 42.1. The first longitudinal support structure 41.1 has a shorter length than the length of the longitudinal second support structure 41.2. Further, the first longitudinal support structure 41.1 is wider than the longitudinal second support structure 41.2. The second longitudinal support structure 41.2 made from carbon fiber-reinforced plastic is terminated 10 m from the tip of the wind turbine blade 10 to avoid damage due to a lightning strike.

(24) FIG. 8 is a sectional view along a shell plane of a third embodiment of the wind turbine blade 10 according to the embodiment of the present invention. The spar cap 40.1 of the wind turbine blade 10 comprises four longitudinal support structure elements 41.1, 41.2, 41.3, 41.4. The first, third and fourth longitudinal support structure elements 41.1, 41.3, 41.4 are made from glass fiber-reinforced plastic and the second longitudinal support structure 41.2 is made from carbon fiber-reinforced plastic. Adjacent longitudinal support structure elements 41.1, 41.2, 41.3, 41.4 are connected to each other by means of structural joints 42.1, 42.2, 42.3. The second longitudinal support structure 41.2 has a greater length than each one of the other longitudinal support structure elements 41.1, 41.3, 41.4. The second longitudinal support structure 41.2 and the third longitudinal support structure 41.3 are arranged at an arrangement angle of α=5° with respect to each other. Further, the third longitudinal support structure 41.3 and the fourth longitudinal support structure 41.4 are arranged at an arrangement angle of α=5° with respect to each other. Thereby, the overall tip sweep S of the wind turbine blade 10 is increased without overloading any of the longitudinal support structure elements 41.1, 41.2, 41.3, 41.4.

(25) FIG. 9 shows schematically a wind turbine 1 comprising wind turbine blades 10 according to the embodiment of the present invention.

(26) Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

(27) For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.