Wind turbine blades

Abstract

This application relates to the field of wind turbine blades and discloses a wind turbine blade comprising at least one web. The web includes a first surface and a second surface disposed opposite to each other along its thickness direction. The web has a plurality of hole structures penetrating the first and second surfaces. The plurality of hole structures includes a first group and a second group. The first group has a decreasing trend from the first surface to the second surface, and the second group has a decreasing trend from the second surface to the first surface. The area formed by the first group and the second group on the first surface is equal to the area formed by both on the second surface. This design balances the strength of the web and maintenance requirements while improving the stability of the wind turbine blade, even with the hole structures in the web.

Description

Technical Field

[0001] This application pertains to the field of wind power generation, and in particular relates to a wind turbine blade. Background Technology

[0002] As the core component of wind turbine generators, wind turbine blades play a crucial role in converting wind energy into mechanical energy. Their working principle is based on the Bernoulli effect in aerodynamics: through a biomimetic airfoil design, the blades create a pressure difference between the upper and lower surfaces of the airflow, generating lift to drive the rotor's rotation.

[0003] To facilitate the maintenance of wind turbine blades, inspection holes can be made in the blades. However, these inspection holes can cause excessive local stress, which can affect the strength of the wind turbine blades. Utility Model Content

[0004] This application provides a wind turbine blade that, while having a perforated structure in the web, balances web strength and maintainability, and improves the stability of the wind turbine blade.

[0005] On one hand, this application provides a wind turbine blade, including: a windward shell, a leeward shell, and at least one web connecting the windward shell and the leeward shell. The web extends along the spanwise direction of the wind turbine blade. The web includes a first surface and a second surface disposed opposite to each other along its thickness direction. The web has a plurality of hole structures penetrating the first surface and the second surface. The plurality of hole structures include a first group and a second group. The first group has a shrinkage trend from the first surface to the second surface, and the second group has a shrinkage trend from the second surface to the first surface. The area formed by the first group and the second group on the first surface is equal to the area formed by both on the second surface.

[0006] In some embodiments of this application, the web includes two fiber layers and a core material along the thickness direction, the two fiber layers being connected to both sides of the core material, and a portion of the fiber layers covering the core material defining the pore structure.

[0007] In some embodiments of this application, a portion of the fiber layer extends from the core material toward the center of the pore structure, and the length of the fiber layer placed within the pore structure is greater than or equal to 10 mm.

[0008] In some embodiments of this application, the hole structure is centrally symmetrical, the area of ​​the larger diameter side of the hole structure is S, the web thickness is F, and 143≤S / F≤19625.

[0009] In some embodiments of this application, the height of the web corresponding to the axis passing through the center of the hole structure along the height direction of the web is H, and the maximum dimension of the hole structure along the height direction of the web is D, where D≤1 / 3H and 2.5≤D / F≤50.

[0010] In some embodiments of this application, the web plate satisfies: 100mm≤D≤500mm, 10mm≤F≤55mm, and 100mm≤H≤5000mm.

[0011] In some embodiments of this application, the web includes a first end and a second end along its own length direction, the height of the first end is greater than the height of the second end, and the length of the web is L; the distance between the center of the hole structure and the first end along the length direction is greater than or equal to 1 / 3L, and the distance between the center of the hole structure and the windward shell and the leeward shell is greater than or equal to 100mm.

[0012] In some embodiments of this application, a plurality of circular hole structures are included, the maximum diameter of the hole structure is D, the distance between the centers of any two hole structures along the length direction of the web is M1, the distance between the centers of any two hole structures along the height direction of the web is M2, M1≥2D, M2≥2D.

[0013] In some embodiments of this application, a cross section along the height direction includes at least two hole structures, and the sum of the maximum dimensions of the at least two hole structures along the height direction is less than or equal to 1 / 3H, where H ≥ 1000 mm.

[0014] In some embodiments of this application, the wind turbine blade includes at least two webs, and the hole structures between adjacent webs are staggered.

[0015] In some embodiments of this application, the windward shell includes a first spar cap and a first trailing edge reinforcement layer. The first spar cap is positioned chordally in the middle of the windward shell, and the first trailing edge reinforcement layer is positioned between the trailing edge of the windward shell and the first spar cap. The leeward shell includes a second spar cap and a second trailing edge reinforcement layer. The second spar cap is positioned chordally in the middle of the leeward shell, and the second trailing edge reinforcement layer is positioned between the trailing edge of the leeward shell and the second spar cap. The wind turbine blade also includes a first web and a second web. The first web is connected between the first spar cap and the second spar cap, and the second web is connected between the first trailing edge reinforcement layer and the second trailing edge reinforcement layer. The second web includes the perforation structure and a notch opened near the blade root of the wind turbine blade. The distance between the notch and the perforation structure is greater than or equal to 400 mm.

[0016] The wind turbine blade of this application embodiment facilitates maintenance and weight reduction by setting a hole structure in the web. The hole structure has a shrinking trend, which makes the hole structure gradually set in the web, reducing stress concentration at the hole structure, thereby taking into account the strength of the web. The first group and the second group of hole structures have opposite shrinking trends, and the hollow areas formed on the first surface and the second surface are equal. This can reduce the mass unevenness caused by the shrinking of the hole structure on both sides of the web thickness direction, reduce the resonance risk of the wind turbine blade, thereby reducing the impact on the natural frequency of the blade, and reducing the bending deformation caused by the different stiffness on both sides of the web thickness direction, thus improving the stability of the wind turbine blade. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a cross-sectional schematic diagram of a wind turbine blade according to some embodiments of this application;

[0019] Figure 2 for Figure 1 A schematic diagram of the web structure in the middle;

[0020] Figure 3 This is another cross-sectional schematic diagram of a wind turbine blade according to some embodiments of this application;

[0021] Figure 4 for Figure 2 Sectional view along the AA direction.

[0022] Explanation of reference numerals in the attached figures:

[0023] 100. Windward side shell; 110. First wing spar cap; 120. First trailing edge reinforcement layer; 200. Leeward side shell; 201. Leading edge; 202. Trailing edge; 210. Second wing spar cap; 220. Second trailing edge reinforcement layer;

[0024] 300, Web; 301, First surface; 302, Second surface; 303, Notch; 311, Fiber layer; 312, Core material; 313, First end; 314, Second end; 320, First web; 330, Second web; X, Tangential direction; Y, Transverse direction. Detailed Implementation

[0025] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0030] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0031] In the description of the embodiments in this application, the technical terms "center," "longitudinal," and "lateral" are used.

[0032] Length, Width, Thickness, Top, Bottom, Front, Back, Left, Right

[0033] "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise"

[0034] The orientation or positional relationship indicated by "axial", "radial", "circumferential", etc., is based on the orientation or positional relationship shown in the accompanying drawings and is only for the purpose of facilitating the description of the embodiments of this application and simplifying the description. It is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this application.

[0035] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0036] As the core device for wind energy conversion, wind turbine generators capture wind energy through aerodynamic design, convert it into mechanical energy, and then convert it into electrical energy through generators, which is ultimately connected to the power grid or supplied to independent loads.

[0037] A wind turbine generator set consists of a rotor system, a transmission system, and a generator. The rotor system, comprising wind turbine blades and a hub, typically consists of three (or two) aerodynamic airfoil structures and is a key component for capturing wind energy. Through surface aerodynamic design (such as biomimetic airfoils), a pressure difference is created in the airflow, driving the wind turbine blades to rotate and converting wind energy into mechanical energy. The hub connecting the wind turbine blades to the main shaft must withstand the aerodynamic loads and centrifugal forces of the blades. It is typically made of high-strength cast aluminum or composite materials to ensure structural rigidity and reliability.

[0038] In the specific working process, when the wind speed is ≥3m / s, the wind turbine blades generate lift and rotate under the action of airflow. At this time, the pitch system adjusts the wind turbine blades to the optimal angle of attack to capture wind energy to the maximum extent. The blades transmit torque to the gearbox (doubly fed induction generator) or directly drive the permanent magnet generator (direct drive generator) through the main shaft. The gearbox increases the rotational speed to meet the electromagnetic induction requirements of the generator. The generator rotor cuts the magnetic field lines to generate alternating current, which is rectified / inverted by a full-power converter (direct drive generator) or a partial-power converter (doubly fed induction generator) to output electrical energy with a stable frequency.

[0039] Wind turbine blades mainly consist of a windward shell, a leeward shell, and a web connecting the windward and leeward shells. The web, perpendicular to the spar caps, converts the bending stress of the upper and lower spar caps into shear stress and distributes it evenly, forming a stable "beam-web" load-bearing system, thus preventing interlayer peeling or breakage of the spar caps due to independent stress.

[0040] As blade length and chord width increase, the number of webs required in the blade structure also increases, leading to an increase in the weight of the webs within the blade. Furthermore, insufficient spacing between two webs or between the web and the shell makes these areas inaccessible to personnel after bonding, making repairs impossible for manufacturing defects in these areas, posing safety hazards to the blade, or even rendering it unusable. To facilitate repairs and reduce weight in the blade area of ​​the web components, perforations are created in the webs. However, the placement of these perforations can cause excessive localized stress in the webs, and arbitrarily creating perforations can affect the shear strength of the webs, thus impacting the stability of the wind turbine blade.

[0041] In view of this, embodiments of this application provide a wind turbine blade, which reduces stress concentration at the hole structure by providing multiple hole structures with a tapering trend along the thickness direction on the web. The hole structures with opposite tapering trends in the thickness direction of the web and the equal formation areas on the first and second surfaces of the web reduce the resonance risk caused by uneven mass on both sides of the web, reduce the impact on the blade's natural frequency, and reduce bending deformation caused by different stiffness on both sides of the web thickness direction, thereby improving stability.

[0042] like Figures 1 to 2 As shown, some optional embodiments of this application provide a wind turbine blade, including: a windward shell 100, a leeward shell 200, and at least one web 300 connected between the windward shell 100 and the leeward shell 200. The web 300 extends along the spanwise Y direction of the wind turbine blade. The web 300 includes a first surface 301 and a second surface 302 disposed opposite to each other along its own thickness direction. The web 300 has a plurality of hole structures 310 penetrating the first surface 301 and the second surface 302. The plurality of hole structures include a first group and a second group. The first group has a decreasing trend from the first surface 301 to the second surface 302, and the second group has a decreasing trend from the second surface 302 to the first surface 301. The area formed by the first group and the second group on the first surface 301 is equal to the area formed by both on the second surface 302.

[0043] The windward shell 100 forms the pressure surface of the wind turbine blade. The windward shell 100 is the convex surface of the blade airfoil, with a large radius of curvature, a smooth surface, and an outward convex shape. Along the spanwise Y of the wind turbine blade, it tends to gradually thin from the blade root to the blade tip.

[0044] For example, the windward shell 100 includes a surface fiber layer 311 and a core layer. The surface fiber layer 311 is made of alternating layers of unidirectional glass fiber (GF) or carbon fiber (CF) fabric (0° / ±45° layup) and bidirectional fabric, mainly bearing longitudinal compressive stress and shear force. The core layer uses balsa wood, PVC foam, or PU foam to support the surface layer with low-density materials, improving the structural compressive stiffness and preventing local buckling.

[0045] The leeward shell 200 forms the suction surface of the wind turbine blade. The leeward shell 200 is a concave surface of the blade airfoil with a small radius of curvature and a relatively flat surface. Its overall thickness is slightly thinner than that of the windward shell 100. Its layer structure is the same as that of the windward shell 100, and will not be described again here.

[0046] For example, a wind turbine blade sequentially comprises a root section, a mid-section, and a tip section along its spanwise Y direction. The root section, the connection area near the hub, accounts for approximately 20%-30% of the total length of the wind turbine blade and primarily bears the mechanical load transmission. The tip section, the last third of the blade, directly affects aerodynamic efficiency and energy capture capability.

[0047] For example, one, two, or three web plates 300 may be provided between the windward housing 100 and the leeward housing 200. The web plate 300 extends from the root of the wind turbine blade towards the tip.

[0048] In some examples, the web 300 can be an I-shaped or box-shaped section.

[0049] In some examples, the areas of the first surface 301 and the second surface 302 of the web 300 are equal. Along the spanwise Y direction, the distance between the first surface 301 and the second surface 302 is equal everywhere.

[0050] The web 300 has a through hole structure that extends along the thickness direction. As an example, when the web 300 is formed, the hole structure is integrally formed on the web 300.

[0051] For example, the hole structure formed on the first surface 301 and the second surface 302 may have the same or different shapes. In some examples, the hole structure on the first surface 301 may be rectangular, circular, pentagonal, triangular, etc., and similarly on the second surface 302.

[0052] For example, at least two hole structures are formed on the web 300. As an example, the web 300 has two hole structures, one hole structure tapering from the first surface 301 to the second surface 302, and the other hole structure tapering from the second surface 302 to the first surface 301. The perforated areas formed by the hole structures on the first surface 301 and the second surface 302 of the web 300 are equal.

[0053] In another example, the web 300 includes three hole structures, one of which tapers along the direction from the first surface 301 to the second surface 302, and the other two hole structures taper along the direction from the second surface 302 to the first surface 301. The perforated areas formed by the hole structures on the first surface 301 and the second surface 302 of the web 300 are equal.

[0054] By incorporating a perforated structure in the web 300, maintenance and weight reduction of the wind turbine blade are facilitated. The perforated structure exhibits a tapering trend, resulting in a gradual transition of the perforation structure across the web 300, reducing stress concentration at the perforation sites and thus ensuring the strength of the web 300. The first and second groups of perforations have opposite tapering trends, and the hollow areas formed on the first surface 301 and the second surface 302 are equal. This reduces the mass unevenness caused by the tapering of the perforations on both sides of the web 300's thickness direction, lowers the resonance risk of the wind turbine blade, thereby reducing the impact on the blade's natural frequency and reducing bending deformation caused by the difference in stiffness on both sides of the web's thickness direction, thus improving the stability of the wind turbine blade. This application can appropriately reduce the blade's moment of mass, further reducing the blade's fatigue load and improving safety.

[0055] In some embodiments of this application, the wind turbine blade includes a main beam disposed between the windward shell 100 and the leeward shell 200. The main beam includes two spar caps and a web 300 between the two spar caps, with the two spar caps respectively disposed on the windward shell 100 and the leeward shell 200.

[0056] For example, the spar cap can be a stacked structure of long strip plates extending along the spanwise Y direction of the blade, with a cross-sectional shape mainly rectangular or trapezoidal. As an example, the spar cap is formed by stacking multiple layers of pultruded carbon fiber plates.

[0057] In some examples, the spar cap may be made of carbon fiber reinforced composite material and / or glass fiber reinforced composite material.

[0058] In some embodiments of this application, the wind turbine blade includes a leading edge 201 and a trailing edge 202. Along the chordal direction X, the leading edge 201 and trailing edge 202 are formed at the junction of the windward shell 100 and the leeward shell 200. The leading edge 201 is the sharp edge of the blade that first contacts the airflow, extending through the blade spanning the Y region, while the trailing edge 202 is the location where the airflow separates.

[0059] like Figures 1 to 3 As shown, in some optional embodiments of this application, the wind turbine blade includes at least two webs 300, and the hole structures between adjacent webs 300 are staggered.

[0060] For example, a wind turbine blade may include two webs 300, three webs 300, etc. The lengths of the multiple webs 300 may be the same or different. As an example, the multiple webs 300 are arranged parallel to each other along the chordal direction X.

[0061] The perforations of two adjacent webs 300 may partially overlap or not overlap, forming a misalignment. As an example, the overlapping area of ​​the perforations of two adjacent webs 300 is less than or equal to half the area of ​​the smallest perforation.

[0062] Furthermore, in some other embodiments of this application, the windward housing 100 includes a first spar cap 110 and a first trailing edge reinforcement layer 120. The first spar cap 110 is positioned in the middle of the windward housing 100 along the chord X direction, and the first trailing edge reinforcement layer 120 is positioned between the trailing edge 202 of the windward housing 100 and the first spar cap 110. The leeward housing 200 includes a second spar cap 210 and a second trailing edge reinforcement layer 220. The second spar cap 210 is positioned in the middle of the leeward housing 200 along the chord X direction, and the second trailing edge reinforcement layer 220 is positioned in the middle of the leeward housing 200. Layer 220 is placed between the trailing edge 202 of the leeward shell 200 and the second spar cap 210; the wind turbine blade also includes a first web 320 and a second web 330. The first web 320 is connected between the first spar cap 110 and the second spar cap 210, and the second web 330 is connected between the first trailing edge reinforcement layer 120 and the second trailing edge reinforcement layer 220. The second web 330 includes a perforated structure and a notch 303 opened near the root of the wind turbine blade. The distance between the notch 303 and the perforated structure is greater than or equal to 400 mm.

[0063] Exemplarily, the first trailing edge reinforcement layer 120 and the second trailing edge reinforcement layer 220 can be made of the same material and have the same shape. In one example, the first trailing edge reinforcement layer 120 is bonded to the core material 312 through a multilayer composite material layup, which can effectively suppress the deformation of the blade trailing edge 202 under complex loads and prevent local instability.

[0064] In another example, the reinforcing fibers primarily consist of multilayer glass fiber reinforced polymer (GRP) or carbon fiber reinforced polymer (CFRP) fabrics, which are composited with resin using a vacuum infusion process to provide high stiffness and tensile strength. The core material 312 commonly uses balsa wood, PET foam, or lightweight honeycomb structures as interlayer materials to reduce weight and improve compressive strength. The adhesive layer uses epoxy resin or polyurethane adhesives to fill gaps, ensuring a tight bond between the layup and the shell.

[0065] As an example, the second web 330 is located between the first trailing edge reinforcement layer 120 and the second trailing edge reinforcement layer 220, serving as an auxiliary support structure to disperse the shear stress in the trailing edge 202 region and prevent the core material 312 from debonding from the ply.

[0066] The second web 330 is provided with a notch 303, which is, exemplarily, C-shaped. The notch 303 can significantly improve local stress concentration. By changing the shape of the notch 303 (such as a C-shaped structure), high-stress areas can be dispersed over a wider material area, reducing the risk of fatigue or failure due to stress superposition.

[0067] For example, the second web 330 has a perforated structure, and the first web 320 also has a perforated structure.

[0068] The hole structure itself is a stress concentration point. If the notch 303 is too close to the hole structure, it will create a stress superposition area, increasing the risk of crack initiation. By maintaining a distance of ≥400mm, the stress can be distributed to different areas, reducing the probability of local fatigue damage.

[0069] In addition, such as Figures 1 to 4 As shown, in some specific embodiments of this application, the web 300 includes two fiber layers 311 and a core material 312 along the thickness direction. The two fiber layers 311 are connected to both sides of the core material 312, and a portion of the fiber layers 311 covers the core material 312 that defines the pore structure.

[0070] The fiber layer 311 is primarily used to enhance shear and buckling resistance. Exemplarily, the fiber layer 311 may comprise one or more layers of glass fiber and / or one or more layers of carbon fiber. As an example, the glass fiber may be an axial glass fiber fabric (such as ±45° biaxial fabric, 0° / 90° orthogonal fabric), with ±45° biaxial fabric stacked to improve the shear resistance of the web 300. In some examples, the fiber layer 311 is composed of pultruded fiberglass preforms with a π-shaped or I-shaped cross-section, enhancing longitudinal stiffness and compressive strength.

[0071] The core material 312 is the core of the lightweight and buckling resistance of the web 300. The fiber layers 311 on both sides wrap the core material 312 and are bonded to the core material 312 through a vacuum infusion process.

[0072] For example, the core material 312 can be made of foam or balsa wood.

[0073] A portion of the fiber layer 311 adheres to the surface of the core material 312, and a portion adheres to the pore structure. The pore structure is covered by the fiber layer 311 to form an inner wall surface, reducing the impact of the exposed core material 312 on the stability and service life of the web 300.

[0074] In one example, the beveled structure of core material 312 creates a gradual trend in the pore structure.

[0075] In another example, the pore structure can be formed by covering one side of the fiber layer 311 or by partially covering both sides of the fiber layer 311. After the pore structure is covered by the fiber layer 311, the two fiber layers 311 are bonded together.

[0076] This application embodiment improves the stability of the web 300 and extends its service life by covering the core material 312 that forms a hole structure.

[0077] Furthermore, in some embodiments of this application, a portion of the fiber layer 311 extends from the core material 312 toward the center of the pore structure, and the length of the fiber layer 311 placed in the pore structure is greater than or equal to 10 mm.

[0078] In one example, a fiber layer 311 covers the inner wall of the completed pore structure and extends a certain length toward the center of the pore structure.

[0079] In another example, after a fiber layer 311 covers the inner wall of the hole structure, it is bonded to another fiber layer 311 and together they extend a certain length toward the center of the hole structure.

[0080] For example, the extension shape of the fiber layer 311 in the pore structure can be annular, and the extension length is greater than 10 mm. For example, the extension length of the fiber layer 311 in the pore structure is a range of one or two values ​​such as 10 mm, 12 mm, 14 mm, 15 mm, 18 mm.

[0081] In the embodiments of this application, the fiber layer 311 extends into the hole by a certain length, thereby increasing the protection range of the fiber layer 311 for the core material 312. Increasing the length of the fiber layer 311 also increases the overall strength of the web 300 and reduces the wear on the inner wall of the hole structure caused by impurities passing through the hole structure or by the passage of maintenance tools.

[0082] In some embodiments of this application, the hole structure is centrally symmetrical, the area of ​​the larger diameter side of the hole structure is S, the thickness of the web is 300 and F, and 143≤S / F≤19625.

[0083] For example, the hole structure can be circular, elliptical, or a regular polygon. A centrally symmetrical hole structure can minimize local stress concentration and reduce the risk of fatigue failure, especially under cyclic shear loads. Symmetry enhances the overall stiffness of the web 300, preventing shear buckling. The symmetrical structure also facilitates alignment during bonding or assembly, improving the reliability of the connection between the web 300 and the main beam and skin.

[0084] A higher S / F ratio (close to 19625) results in a large bore area and a thinner web 300, suitable for low shear load regions, reducing weight and improving material utilization. A lower S / F ratio (close to 143) results in a smaller bore area and a thicker web 300, enhancing shear resistance in high load regions (such as near the blade root). By adjusting the S / F ratio, the vibration frequency of the web 300 can be controlled, avoiding resonance with the overall blade and balancing blade safety and weight. An excessively large S / F leads to an excessively large bore area, resulting in insufficient remaining material, weakening the shear resistance of the web 300, and easily causing shear fracture or buckling.

[0085] In some embodiments of this application, the height of the web 300 corresponding to the axis of the center of the through hole structure along the height direction of the web 300 is H, and the maximum dimension of the hole structure along the height direction of the web 300 is D, where D≤1 / 3H and 2.5≤D / F≤50.

[0086] For example, the height of the web 300 decreases progressively from the blade root to the blade tip along the spanwise Y direction of the wind turbine blade; therefore, the height of the web 300 is variable. The dimensions of the perforation structure should be determined based on the height of the web 300 at its location. In one example, the perforation structure includes multiple axes passing through the center, wherein the height of the web 300 corresponding to the axis along the height direction determines the maximum dimension of the perforation structure along the height direction.

[0087] In some examples, the hole structure is a centrally symmetrical figure, and the maximum dimension of the hole structure along the height direction of the web 300 can be the maximum dimension of the hole structure.

[0088] In other examples, the hole structure is centrally symmetric, and the maximum dimension of the hole structure along the height direction of the web 300 can be smaller than the maximum dimension along the span Y direction of the web 300.

[0089] As an example, D can be a range formed by one or two of the values ​​of 1 / 3H, 1 / 4H, 1 / 5H, and 1 / 6H.

[0090] As an example, D / F can be a range consisting of one or two of the following: 2.5, 3, 3.5, 4.6, 8, 10, 18, 20, 24, 30, 32, 40, 41, 49, and 50.

[0091] In some embodiments of this application, the web 300 satisfies: 100mm≤D≤500mm, 10mm≤F≤55mm, and 100mm≤H≤5000mm.

[0092] As an example, D is a range consisting of one or two of 100mm, 200mm, 250mm, 310mm, 400mm, 450mm, and 500mm.

[0093] As an example, F is a range consisting of one or two of 10mm, 12mm, 15mm, 22mm, 30mm, 35mm, 40mm, 50mm, and 55mm.

[0094] As an example, H is a range consisting of one or two of the following: 100mm, 500mm, 800mm, 1000mm, 1200mm, 2000mm, 3000mm, 4400mm, and 5000mm.

[0095] In addition, in other optional embodiments of this application, the web 300 includes a first end 313 and a second end 314 along its own length direction. The height of the first end 313 is greater than the height of the second end 314, and the length of the web 300 is L. The distance between the center of the hole structure and the first end 313 along the length direction is greater than or equal to 1 / 3L, and the distance between the center of the hole structure and the windward shell 100 and the leeward shell 200 is greater than or equal to 100mm.

[0096] For example, a C-shaped notch is provided at the first end 313 of the web 300.

[0097] The length direction of the web 300 is aligned with the spanwise Y direction of the wind turbine blade, and the thickness direction of the web 300 is aligned with the chordwise X direction of the wind turbine blade. The height direction of the web 300 is perpendicular to both the thickness direction and the length direction.

[0098] The first end 313 of the web 300 has a relatively large height, typically corresponding to a high stress concentration area near the blade root. Setting the distance between the center of the hole structure and the first end 313 to ≥1 / 3L avoids creating holes in the front section (high load area) of the web 300, reducing the risk of stress superposition. The hole structure is located in the middle and rear section of the web 300, which reduces the interference of the hole on the main force transmission path and balances the shear force distribution.

[0099] The center of the hole structure should be at least 100mm away from the windward / leeward side of the shell to ensure sufficient material thickness at the bonding area between the hole edge and the shell, preventing delamination or adhesive tearing under shear or tensile loads. Hole structures located away from the shell edge can prevent crack propagation due to local buckling, especially under high fatigue load conditions (such as typhoons and turbulence).

[0100] When the hole structure is far from the edge of the shell, it can avoid obstruction of resin flow or failure of vacuum bag seal, thus improving the molding quality of the web plate 300.

[0101] Furthermore, in some embodiments of this application, the wind turbine blade includes a plurality of circular hole structures, the maximum diameter of the hole structure is D, the distance between the centers of any two hole structures along the length direction of the web 300 is M1, the distance between the centers of any two hole structures along the height direction of the web 300 is M2, M1≥2D, M2≥2D.

[0102] In one example, the web 300 has two, three, or four hole structures, and the multiple hole structures can be discretely distributed or arranged in rows and columns.

[0103] Stress concentration is prone to occur at the edges of hole structures. When the distance between adjacent holes is too small, the stress fields will superimpose, leading to local material overload. By setting the distance between M1 and M2 to be ≥ 2D, the stress superposition effect between holes can be significantly reduced, preventing crack initiation or propagation.

[0104] The web 300 needs to bear shear force and support the main beam. Sufficient spacing can retain more continuous fiber material and avoid the decrease in stiffness of the web 300 due to dense holes.

[0105] Insufficient spacing between the holes can lead to local stiffness differences in the web within 300 mm, increasing the risk of resonance. A spacing of ≥2D results in a more uniform distribution of structural modes, reducing the vibration amplitude during blade operation.

[0106] In some embodiments of this application, a cross section along the height direction includes at least two hole structures, the sum of the maximum dimensions of the at least two hole structures along the height direction is less than or equal to 1 / 3H, and H≥1000mm.

[0107] In one example, a cross-section along the height direction includes two hole structures. The maximum dimension of the first hole structure along the height direction is D1, and the maximum dimension of the second hole structure along the height direction is D2. Wherein, D1+D2≤1 / 3H.

[0108] The overall size of the restricted hole structure (≤1 / 3H) ensures that the web 300 retains sufficient effective load-bearing area to maintain shear and buckling resistance.

[0109] Some embodiments of this application also provide a method for manufacturing wind turbine blades, including steps S1 and S2.

[0110] S1: A web 300 with multiple pore structures is prepared, wherein a portion of the pore structures has a tapering tendency along a first direction, and another portion of the pore structures has a tapering tendency along a second direction, and the two portions of the pore structures form equal areas on the two surfaces of the web 300 along the thickness direction, while the first and second directions are opposite.

[0111] The web 300 includes a first surface 301 and a second surface 302 disposed opposite to each other along its thickness direction. The first direction is from the first surface 301 to the second surface 302, and the second direction is from the second surface 302 to the first surface 301. The area formed by the plurality of hole structures on the first surface 301 is equal to the area formed on the second surface 302.

[0112] For example, the web 300 is hand-laid or molded, forming a porous structure during the hand-lay or mold-forming process.

[0113] S2: Install the web plate 300 between the windward shell 100 and the leeward shell 200 of the wind turbine blade.

[0114] For example, the web plate 300 is bonded to the windward housing 100 and the leeward housing 200. When the windward housing 100 and the leeward housing 200 are molded together, the web plate 300 is bonded between the windward housing 100 and the leeward housing 200.

[0115] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A wind turbine blade, characterized in that include: The windward side shell, the leeward side shell, and at least one web plate connecting the windward side shell and the leeward side shell, the web plate being arranged to extend along the spanwise direction of the wind turbine blade; The web includes a first surface and a second surface disposed opposite to each other along its own thickness direction. The web has a plurality of hole structures penetrating the first surface and the second surface. The plurality of hole structures include a first group and a second group. The first group has a shrinkage trend from the first surface to the second surface, and the second group has a shrinkage trend from the second surface to the first surface. The area formed by the first group and the second group on the first surface is equal to the area formed by the two groups on the second surface.

2. A wind turbine blade according to claim 1, characterised in that The web includes two fiber layers and a core material along the thickness direction. The two fiber layers are connected to both sides of the core material, and a portion of the fiber layers covers the core material that defines the pore structure.

3. A wind turbine blade according to claim 2, characterised in that A portion of the fiber layer extends from the core material toward the center of the pore structure, and the length of the fiber layer placed within the pore structure is greater than or equal to 10 mm.

4. A wind turbine blade according to claim 1, characterised in that The hole structure is centrally symmetrical, the area of ​​the larger diameter side of the hole structure is S, the thickness of the web is F, and 143≤S / F≤19625.

5. The wind turbine blade according to claim 4, characterized in that, Along the height direction of the web, the height of the web corresponding to the axis passing through the center of the hole structure is H, and the maximum dimension of the hole structure along the height direction of the web is D, where D≤1 / 3H and 2.5≤D / F≤50.

6. The wind turbine blade according to claim 5, characterized in that, The web plate satisfies the following conditions: 100mm≤D≤500mm, 10mm≤F≤55mm, 100mm≤H≤5000mm.

7. The wind turbine blade according to claim 4, characterized in that, The web includes a first end and a second end along its own length direction, the height of the first end is greater than the height of the second end, and the length of the web is L; The distance between the center of the hole structure and the first end along the length direction is greater than or equal to 1 / 3L, and the distance between the center of the hole structure and the windward shell and the leeward shell is greater than or equal to 100mm.

8. The wind turbine blade according to claim 4, characterized in that, It includes multiple circular hole structures, the maximum diameter of the hole structure is D, the distance between the centers of any two hole structures along the length direction of the web is M1, the distance between the centers of any two hole structures along the height direction of the web is M2, M1≥2D, M2≥2D.

9. The wind turbine blade according to claim 8, characterized in that, A cross section along the height direction includes at least two hole structures, and the sum of the maximum dimensions of the at least two hole structures along the height direction is less than or equal to 1 / 3H, where H ≥ 1000 mm.

10. The wind turbine blade according to claim 1, characterized in that, It includes at least two webs, and the hole structures between two adjacent webs are staggered.

11. The wind turbine blade according to claim 10, characterized in that, The windward shell includes a first spar cap and a first trailing edge reinforcement layer. The first spar cap is positioned chordally in the middle of the windward shell, and the first trailing edge reinforcement layer is positioned between the trailing edge of the windward shell and the first spar cap. The leeward shell includes a second spar cap and a second trailing edge reinforcement layer. The second spar cap is positioned chordally in the middle of the leeward shell, and the second trailing edge reinforcement layer is positioned between the trailing edge of the leeward shell and the second spar cap. The wind turbine blade also includes a first web and a second web. The first web is connected between the first spar cap and the second spar cap, and the second web is connected between the first trailing edge reinforcement layer and the second trailing edge reinforcement layer. The second web includes the hole structure and a notch opened near the blade root of the wind turbine blade. The distance between the notch and the hole structure is greater than or equal to 400 mm.

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