Wind turbine rotor blades

Abstract

The present invention relates to a wind turbine rotor blade (110) comprising a half-shell (134) having a spar cap (138) and a first shear web (140), wherein the first shear web (140) is connected to the spar cap (138), the spar cap (138) extending in the spanwise direction (120) of the wind turbine rotor blade (110) and having a centerline (121); the first shear web (140) has a first portion (140a) starting at the root portion (114) of the rotor blade and a subsequent second portion (140b); the first portion (140a) is oriented at an angle α relative to the centerline (121) such that the distance (154) from the first shear web (140) to the centerline (121) of the spar cap (138) decreases along the first portion (140a).

Description

Technical Field

[0001] This disclosure relates to the field of manufacturing wind turbine rotor blades. Background Technology

[0002] Wind turbines with rotor blades are widely known in the prior art and are used to convert wind energy into electrical energy. Wind turbine rotor blades are typically manufactured in a shell design and comprise several components, such as an aerodynamic shell, made of fiber-reinforced laminates. Typically, in a first step, a half-shell is produced from many layers of fiber composite material, within which a support structure, such as a spars cap, is incorporated. A resin infusion process is performed, and the half-shell cures in its half-shell mold. In a second step, the manufactured half-shells are stacked and joined together to produce the wind turbine rotor blade. The half-shells can be interconnected internally within the rotor blade by one or more (shear-resistant) webs or spars extending along the longitudinal direction of the rotor blade. These webs or spars absorb forces between the half-shells, particularly during operation, and thus stabilize the aerodynamic shape of the rotor blade during operation. The half-shells, and thus the resulting wind turbine rotor blade, can be segmented for the manufacture of so-called split or segmented wind turbine rotor blades. Alternatively, the rotor blade can be manufactured in a so-called monolithic manufacturing process. Summary of the Invention

[0003] One object of the present invention is to provide a wind turbine rotor blade that provides particularly high stiffness and enables particularly efficient manufacturing and finishing processes.

[0004] This objective is achieved, in particular, through the subject matter of the main aspects of the invention. Advantageous embodiments and other improvements are given in the appended aspects of the invention and are readily understood from the description and drawings.

[0005] A wind turbine rotor blade is disclosed, comprising a half-shell with a spars cap and a first shear web. The first shear web is connected to the spars cap. The spars cap extends in the spanwise direction of the wind turbine rotor blade and has a centerline (also referred to as the central axis). The first shear web has a first portion starting at the root portion of the rotor blade and a subsequent second portion. The first portion is oriented at an angle α relative to the centerline, such that the distance from the first shear web to the centerline of the spars cap decreases along the first portion, starting from the root tip of the rotor blade.

[0006] Typically, as described above, a wind turbine rotor blade comprises two semi-shells joined together at a joining flange at the leading and trailing edges along the spanwise direction to form the aerodynamic shell of the wind turbine rotor blade. Each semi-shell includes a sparsity cap, wherein the sparsity caps are arranged opposite each other and extend along the spanwise direction. A shear web connects the two sparsity caps. In the following text, for clarity, only one semi-shell and one sparsity cap will be mentioned.

[0007] The disclosed wind turbine rotor blade is characterized by a shear web having two portions oriented at an angle relative to each other. The shear web includes a first portion extending at an angle relative to a centerline. Therefore, the distance between the centerline and the first portion decreases from the rotor blade root tip. For example, the second portion extends approximately parallel to the centerline of the spars cap. "Approximately" means, for example, that slight deviations may occur due to manufacturing tolerances. For example, the second portion may be oriented at an angle of less than 0.5° relative to the centerline.

[0008] Due to the specially arranged first section, the described wind turbine rotor blade has a shear web, which not only contributes to the very rigid structure of the rotor blade but also enables easy manufacturing and finishing processes. Because of the angular arrangement of the first section, a high degree of flexibility is achieved regarding the space within the wind turbine rotor blade, starting from the root tip, especially when the shear web is combined with another shear web. For example, this allows workers to better access certain sections of the shear web, for example, for finishing or repair processes. For instance, from the rotor blade root tip, applying a covering laminate to the shear web on the first few meters of the wind turbine rotor blade is significantly simplified. As another example, it facilitates the removal of excess material such as adhesives, where, in particular, no specific tools are required.

[0009] Compared to a completely straight shear web, the shear web according to the invention allows the space inside the rotor blade, in the root portion, to be designed by means of an angled first section so that workers can perform repair, cleaning, or finishing tasks, especially after the two half-shells are closed and joined together to form the entire rotor blade.

[0010] The spar cap can also be referred to as a main laminate or strip. For example, the spar cap is formed from multiple fiber layers or stacked by pultruded strips. The spar cap can be integrally formed with the rotor blade half-shell. Alternatively, the spar cap can be a prefabricated component, which can be included in a layup formed of fiber material and core material.

[0011] The shear web connects to the spar cap along its entire length. In other words, the shear web extends along the entire length of the spar cap. The same applies to the opposite spar cap of the second half-shell, such that the shear web connects only to the spar cap and not to the outer half-shell of the spar cap.

[0012] The distance from the shear web to the centerline decreases linearly, or in other words, it decreases strictly monotonically. This distance is measured along the chord direction transverse to the centerline or spanwise direction.

[0013] The root portion of the rotor blade is the first section of the wind turbine rotor blade and is arranged opposite to the tip portion of the wind turbine rotor blade. The root portion of the rotor blade is a part of the wind turbine rotor blade that connects to the rotor hub. The root portion of the rotor blade includes the root tip of the rotor blade.

[0014] The first part has an axial end that defines the axial end of the entire first shear web. The axial end of the entire first shear web faces the root end of the rotor blade. In other words, the first component of the shear web—viewed from the root end of the rotor blade—is the first part, followed by the second part.

[0015] Starting from the root portion of the rotor blade means that the first part of the first shear web can start from the root end of the rotor blade, or from a certain distance from the root end of the rotor blade, for example, 3 m from the root end of the rotor blade.

[0016] The first and second parts of the shear web can also be considered as two corresponding different planes, and the shear web extends along the spanning direction according to these two different planes.

[0017] According to one embodiment, the first shear web has a bend at the transition point from the first portion to the second portion. This emphasizes that the two portions of the shear web are oriented at an angle relative to each other. These two portions can be manufactured as two straight, single components to simplify the manufacturing process. This contributes to the aforementioned functions and advantages.

[0018] According to the implementation, the angle α between the first part and the centerline is less than 2 degrees. This ensures a smooth transition from the first part to the second part. This helps to avoid localized stress concentration at the bend, avoid sag problems in the fiber layer and core material forming the shear web, and avoid highly discontinuous characteristics of the wind turbine rotor blades, such as abrupt changes in torsional stiffness distribution and shear center location, which can negatively impact the structural performance of the wind turbine rotor blades.

[0019] According to the embodiment, the transition point is located at a distance of 15% to 50% of the total length of the rotor blade, starting from the root end of the rotor blade; preferably, it is located between 20% and 40% or 30% and 38% of the total length of the rotor blade, or at 33% or 35% of the total length of the rotor blade. In other words, the ratio of the length of the first portion to the length of the second portion is between 1:3 and 1:1, preferably about 1:2. This contributes to the aforementioned functions and advantages regarding a smooth transition.

[0020] According to the embodiment, the distance from the second portion to the centerline remains substantially constant along the second portion, i.e., along the spanwise direction. Therefore, the second portion of the shear web is similar to the portion of a conventional shear web in the outer region facing the rotor blade tip.

[0021] According to one embodiment, the wind turbine rotor blade includes a second shear web. The second shear web is connected to the spar cap. The second shear web is arranged at a certain distance from the first shear web. Starting from the root end of the rotor blade, i.e., viewed from the root end of the rotor blade, the distance between the two shear webs decreases along a first portion of the first shear web.

[0022] The same features and embodiments as described above apply to the second shear web as those to the first shear web. The second shear web is also connected to the spar cap of the second half-shell. Like the first shear web, the second shear web connects to the spar caps of both half-shells along its entire length. Preferably, the second shear web has the same length as the first shear web, except for any deviations caused by manufacturing tolerances. The same length means that the two shear webs have the same start and end points relative to the longitudinal direction of the rotor blades.

[0023] With two shear webs, a centrally located torsion box, similar to that of an aircraft wing, can be configured. In this case, the torsion box is formed by two shear webs extending along the spanwise direction and two spar caps, each half-shell having one spar cap as described above. The aforementioned advantages and functions are particularly beneficial in this configuration. The angled first portion of the first shear web increases the space between the two shear webs, while neither shear web is connected to the half-shell outside the spar cap. This allows workers easier access between the shear webs within the rotor blades for repair, cleaning, or finishing tasks.

[0024] Similarly, this distance is measured along a chordal direction transverse to the centerline or span.

[0025] According to one embodiment, the second shear web has a first portion starting at the root portion of the rotor blade and a subsequent second portion. The first portion is oriented at an angle β relative to the centerline, such that, starting from the tip of the rotor blade root (e.g., viewed from the tip of the rotor blade root), the distance from the second shear web to the centerline of the spar cap decreases along the first portion. The first and second shear webs converge toward each other along their first portions.

[0026] In this embodiment, the two shear webs preferably have opposing first and second portions. Preferably, the shear webs are arranged mirror-symmetrically, except for any manufacturing tolerances. The two shear webs are arranged at a distance from each other along their entire length. This contributes to a very large space between the two shear webs within the wind turbine rotor blade, in the root portion of the rotor blade, and thus contributes to the aforementioned advantages and functions.

[0027] According to the embodiment, the second shear web has a bend at the transition point from the first portion to the second portion. The same applies to the above description of the bend in the first shear web.

[0028] According to the embodiment, the bends of the first and second shear webs are located at the same positions in the spanwise direction of the rotor blades. This facilitates the efficient arrangement of the shear webs and thus contributes to a smooth and uniform load distribution during the operation of the wind turbine rotor blades.

[0029] According to the embodiment, the angle β between the first portion of the second shear web and the centerline is less than 2 degrees. Similar to the angle α above, the angle β between the second portion and the centerline is less than 2 degrees.

[0030] According to the implementation method, angles α and β have the same value. This contributes to a smooth and uniform distribution of the aforementioned load.

[0031] According to one embodiment, the first and second portions of the first and / or second shear web are manufactured as separate components. These separate components are joined together to form the first or second shear web. This allows for the manufacture of straight portions of the shear web, which is relatively easier than manufacturing an entire shear web with two portions, such as a bent portion, at once.

[0032] In the following, wind turbine rotor blades will be explained in more detail with reference to the accompanying drawings, based on exemplary embodiments. The accompanying drawings are included to provide further understanding. In the drawings, elements with the same structure and / or function may be designated by the same reference numerals. It should be understood that the embodiments shown in the drawings are illustrative representations and are not necessarily drawn to scale. Descriptions of elements or components in the following drawings will not be repeated in each figure as long as the elements or components correspond to each other in function in different figures. For clarity, elements may not appear with corresponding reference numerals in all figures. Attached Figure Description

[0033] In the attached diagram:

[0034] Figure 1 A schematic diagram of a wind turbine is shown.

[0035] Figure 2 A schematic diagram of the rotor blades is shown.

[0036] Figure 3 A schematic diagram of the cross-section of a wind turbine rotor blade is shown.

[0037] Figure 4 A wind turbine rotor blade according to an embodiment of the present invention is shown.

[0038] Figures 5 to 7 A wind turbine rotor blade according to another embodiment of the present invention is shown. Detailed Implementation

[0039] Figure 1 A schematic diagram of a wind turbine 100 including a tower 102 is shown. The tower 102 is fixed to the ground by means of a base 104. A nacelle 106 is rotatably mounted at one end of the tower 102 opposite to the ground. For example, the nacelle 106 includes a generator connected to a rotor 108 via a rotor shaft (not shown). The rotor 108 includes one or more rotor blades 110 (of the wind turbine) arranged on a rotor hub 112.

[0040] During operation, rotor 108 is configured to rotate via an airflow, such as wind. This rotational motion is transmitted to a generator via the rotor shaft and, if necessary, via a gearbox. The generator converts the mechanical energy of rotor 108 into electrical energy.

[0041] Figure 2An exemplary embodiment of a wind turbine rotor blade 110 is shown. The wind turbine rotor blade 110 has the shape of a conventional rotor blade and has a rotor blade root portion 114 facing the rotor hub 112. The rotor blade root portion 114 generally has a generally circular cross-section. Following the rotor blade root portion 114 are a transition portion 116 and a profile portion 118. The wind turbine rotor blade 110 has a pressure side 122 and an opposite suction side 124 in the spanwise direction 120 (also referred to as the main extension direction or longitudinal direction). The wind turbine rotor blade 110 is substantially hollow internally.

[0042] In the rotor blade root portion 114, a rotor blade root end portion 126 with a flange connection portion 128 is provided, through which the wind turbine rotor blade 110 can be mechanically connected to the pitch bearing or extender. The wind turbine rotor blade 110 has a rotor blade tip portion 130 and a rotor blade root end portion 126 on the opposite side. The wind turbine rotor blade 110 can be a segmented rotor blade.

[0043] Figure 3 A schematic cross-sectional profile 132 of an exemplary embodiment of a wind turbine rotor blade 110 is shown (see [link]). Figure 2 The cross-sectional plane extends perpendicular to the spanwise direction 120. The wind turbine rotor blade 110 includes an (aerodynamic) shell 136 consisting of two half-shells 134, one half-shell 134 corresponding to the pressure side 122 and the other half-shell 134 corresponding to the suction side 124. The two half-shells 134 are firmly connected to each other along the spanwise direction 120 at opposing connection regions, i.e., at the joining flange line, at the leading edge 133 and trailing edge 135. Each half-shell 134 has a sparsity cap 138 embedded in the shell structure. The sparsity cap 138 may also be referred to as the "primary laminate" and bears the main load during the operation of the wind turbine rotor blade 110. The wind turbine rotor blade 110 also includes two shear webs 140, 142 connecting the sparsity caps 138.

[0044] Figure 4 A schematic top view of a half-shell 134 of a wind turbine rotor blade 110 according to an embodiment of the present invention is shown. The wind turbine rotor blade 110 includes a first shear web 140 and a second shear web 142. The wind turbine rotor blade 110 includes two half-shells 134 (the second half-shell is not shown), wherein each half-shell 134 includes a sparsity cap 138 (in... Figure 4The diagram indicates one of the spar caps 138. Two spar caps 138 are arranged opposite each other and extend along the spanwise direction 120. Each shear web 140, 142 connects the two spar caps 138. In other words, each shear web 140, 142 extends along or on the spar cap 138 and is not connected to the outer half-shell 134 of the spar cap 138.

[0045] Both shear webs 140 and 142 are formed of a sandwich material comprising a core material panel and an outer fiber-reinforced laminate.

[0046] Figure 4 The wing cap 138 indicated in the document has a centerline 121, i.e., a central axis.

[0047] The second shear web 142 is a conventional straight shear web that extends parallel to the centerline 121.

[0048] The first shear web 140 includes a first portion 140a and a second portion 140b. The first portion 140a begins at the rotor blade root portion 114 (see [reference]). Figure 2 The first portion 140a is oriented at an angle α relative to the centerline 121. In this example, the angle α is 2°. The second portion 140b extends parallel to the centerline 121. The first portion 140a and the second portion 140b can also be considered as a first plane and a second plane, along which the first shear web 140 extends.

[0049] Due to this configuration, the first shear web 140 has a bend 156 at the transition point 158 ​​from the first portion 140a to the second portion 140b. The transition point 158 ​​is located at a distance of 35% of the total rotor blade length, starting from the rotor blade root end 126. This allows for a smooth transition from the first portion 140a to the second portion 140b. Knowing the value of the maximum distance 154 between the first portion 140a and the centerline 121, i.e., the value of the maximum distance 154 at the axial end of the first shear web 140 facing the rotor blade root end 126, or the value of the angle α, the length 144 from the end of the first shear web 140 to the bend 156 can be determined using trigonometric functions. In other words, the position where the two extending planes of the first portion 140a and the second portion 140b intersect each other can be determined.

[0050] In the described embodiment, starting from or viewed from the rotor blade root end 126, the distance 154 between the first shear web 140 and the centerline 121 decreases linearly along the first portion 140a. The distance 154 remains constant along the second portion 140b.

[0051] according to Figure 4 The wind turbine rotor blades 110 can achieve the functions and advantages described above.

[0052] Figures 5 to 7 This relates to a wind turbine rotor blade 110 according to another embodiment of the invention. Figures 5 to 7 The wind turbine rotor blade 110 is equivalent to the above. Figure 4 The rotor blades. Therefore, the above explanation also applies. Compared to the above case, the second shear web 142 also includes two parts, namely the first part 142a and the second part 142b. Preferably, the second shear web 142 is mirror-symmetrical to the first shear web 140.

[0053] The first portion 142a of the second shear web 142 is oriented at an angle β relative to the centerline 121. In this example, the angle β is 2°. The second portion 142b extends parallel to the centerline 121. The first portion 142a and the second portion 142b can also be considered as a first plane and a second plane, along which the second shear web 142 extends.

[0054] The second shear web 142 has a bend 157 at the transition point 159 from the first portion 142a to the second portion 142b. The bend 156 of the first shear web 140 is preferably located at the same position on the spanwise direction 120 of the rotor blade 110, as the bend 157 of the second shear web 142. The angle β between the first portion 142a of the second shear web 142 and the centerline 121 is less than 2°. Angles α and β preferably have the same value.

[0055] Viewed from the rotor blade root end 126, the distance 154 from the centerline 121 of the second shear web 142 to the spar cap 138 decreases along the first portion 142a. In other words, starting from the rotor blade root end 126, the distance 160 between the two shear webs 140, 142 decreases along the corresponding first portion 140a of the first shear web 140 or the first portion 142a of the second shear web 142. Therefore, starting from the axial ends of the two shear webs 140, 142 facing the root end 126, the two shear webs 140, 142 converge toward each other along their first portions 140a, 142a.

[0056] Figure 6 and Figure 7 The diagram shows the cross-sectional planes AA and BB. Figure 5 A cross-sectional view of the rotor blade 110 of a wind turbine. (For example, it can be seen in...) Figure 6 What we see in the middle, and like Figure 7The distance 160 between the two shear webs 140 and 142 is much larger than the distance 160 between the two first parts 140a and 142a, compared to the distance 160 between the second parts 140b and 142b shown. The available space on the spar cap 138 is used to create as much space as possible between the shear webs 140 and 142. In... Figure 6 In the root end portion 114 of the wind turbine rotor blade 110 shown, due to the specially designed angled first portions 140a, 142b, workers therefore have more space to perform any work on the shear web.

[0057] In the two described embodiments of the present invention, the first portions 140a, 142a and the second portions 140b, 142b of the first shear web 140 and / or the second shear web 142 are manufactured as separate components, which are then aligned and / or connected to each other to form the first shear web 140 and the second shear web 142. List of reference numerals 100 wind turbines 102 towers 104 bases Cabin 106 108 rotors 110 Wind turbine rotor blades 112 Rotor Hub 114 Rotor blade root section 116 Transition Section 118 Outline Section 120 Expansion Direction 121 Centerline 122 Pressure side 124 Suction Side 126 Rotor blade root tip 128 Flange Connection 130 Rotor blade tip 132 Cross-sectional profile 133 Past Fate 134 Semi-shell 135 trailing edge 136 Aerodynamic shell 138 Wing-shaped cap 140 First shear web 140a Part 1 140b Part 2 142 Second shear web 142a Part 1 142b Part Two α angle β angle 144 Length 154 Distance 156 Bending section 157 Bending section 158 Transition Point 159 Transition Point 160 Another distance AA cross-sectional plane BB cross-sectional plane

Claims

1. A wind turbine rotor blade (110), the wind turbine rotor blade (110) comprising a semi-shell (134) having a sparsity cap (138) and a first shear web (140), wherein, The first shear web (140) is connected to the spar cap (138), which extends in the spanwise direction (120) of the wind turbine rotor blade (110) and has a centerline (121). The first shear web (140) has a first portion (140a) starting at the root portion (114) of the rotor blade and a subsequent second portion (140b). The first portion (140a) is oriented at an angle α relative to the centerline (121) such that the distance (154) from the first shear web (140) to the centerline (121) of the spar cap (138) decreases along the first portion (140a) starting from the root end (126) of the rotor blade.

2. The wind turbine rotor blade (110) according to claim 1, wherein, The first shear web (140) has a bend (156) at the transition point (158) from the first portion (140a) to the second portion (140b).

3. The wind turbine rotor blade (110) according to claim 1 or 2, wherein, The angle α between the first part (140a) and the center line (121) is less than 2 degrees.

4. The wind turbine rotor blade (110) according to any one of claims 1 to 3, wherein, The transition point (158) is located at a distance of 15% to 40% of the length of the rotor blade, starting from the root end (126) of the rotor blade.

5. The wind turbine rotor blade (110) according to any one of claims 1 to 4, wherein, The distance (154) to the center line (121) of the second part (140b) remains substantially constant along the second part (140b).

6. The wind turbine rotor blade (110) according to any one of claims 1 to 5 further comprises a second shear web (142), wherein, The second shear web (142) is connected to the spar cap (138). The second shear web (142) is arranged at a distance (160) from the first shear web (140). Starting from the root end (126) of the rotor blade, the distance (160) between the two shear webs (140, 142) decreases along the first portion (140a) of the first shear web (140).

7. The wind turbine rotor blade (110) according to claim 6, wherein, The second shear web (142) has a first portion (142a) starting at the root portion (114) of the rotor blade and a subsequent second portion (142b). The first portion (142a) is oriented at an angle β relative to the centerline (121), such that the distance (154) from the second shear web (142) to the centerline (121) of the spar cap (138) decreases along the first portion (142a), starting from the root end (126) of the rotor blade. The first shear web (140) and the second shear web (142) converge toward each other along their first portions (140a, 142a).

8. The wind turbine rotor blade (110) according to claim 7, wherein, The second shear web (142) has a bend (157) at the transition point (159) from the first part (142a) to the second part (142b).

9. The wind turbine rotor blade (110) according to claim 8, wherein, The bent portion (156) of the first shear web (140) and the bent portion (157) of the second shear web (142) are located at the same position in the spanwise direction (120) of the rotor blade (110).

10. The wind turbine rotor blade (110) according to any one of claims 7 to 9, wherein, The angle β between the first part (142a) and the center line (121) is less than 2 degrees.

11. The wind turbine rotor blade (110) according to any one of claims 7 to 10, wherein, The angle α and the angle β have the same value.

12. The wind turbine rotor blade (110) according to any one of claims 7 to 11, wherein, The first portion (140a, 142a) and the second portion (140b, 142b) of the first shear web (140) and / or the second shear web (142) are manufactured as separate components.

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