Wind turbine blade

Abstract

A wind turbine blade, comprising: a blade body, the blade body comprising a hollow cavity; and a counterweight assembly mounted in the hollow cavity of the blade body, the counterweight assembly being connected to the blade body by means of a first elastic adhesive layer, and the first elastic adhesive layer comprising an adhesive having a tensile modulus less than 2 GPa. The present application is used for solving the problem of damage or even falling off caused by stress concentration between a counterweight assembly and a wind turbine blade.

Description

Wind turbine blades

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application 202411476004.7 entitled "Wind Turbine Blade", filed on October 22, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application pertains to the field of wind power generation, and in particular relates to a wind turbine blade. Background Technology

[0004] Wind turbine blades are the rotating components of a wind turbine, consisting of blades and a hub, and are one of the key components of a wind turbine. Based on aerodynamic principles, the blades are shaped much like airplane wings, characterized by their long and thin shape. When wind blows across the blades, the curved surfaces create different airflow speeds and pressure distributions, generating a forward aerodynamic force that causes the blades to rotate. This rotation drives the rotation of the wind turbine rotor, thereby generating electricity.

[0005] When wind turbine blades reach a certain rotational speed, vibration occurs due to their own structure and the influence of turbulent wind. Severe vibration can damage the wind turbine generator. To prevent excessive blade vibration from damaging the wind turbine generator, counterweights are installed on the wind turbine blades to control and reduce vibration levels. These counterweights typically consist of lead or iron blocks, installed at or near the blade's center of gravity to reduce the difference in weight and moment of mass between the three blades, thereby improving dynamic balance and the stability of the wind turbine during operation.

[0006] However, existing counterweights are mostly bonded to the wind turbine blades with molding adhesive. When the wind turbine blades are subjected to load and deform, stress concentration will occur between the counterweights and the wind turbine blades, which will lead to damage or even cause the counterweights to fall off. Summary of the Invention

[0007] This application provides a wind turbine blade that can reduce stress concentration between the counterweight assembly and the blade body, and improve the connection stability of the counterweight assembly.

[0008] This application provides a wind turbine blade, comprising: a blade body, the blade body including a windward shell, a leeward shell, and a hollow cavity formed by the windward shell and the leeward shell; a counterweight assembly, the counterweight assembly being installed in the hollow cavity of the blade body; and a first elastic adhesive layer, the counterweight assembly being connected to the blade body through the first elastic adhesive layer, the first elastic adhesive layer comprising an adhesive with a tensile modulus of less than 2 GPa; wherein the deformation of the counterweight assembly is isolated from the deformation of the blade body through the first elastic adhesive layer, so that the counterweight assembly and the blade body deform independently.

[0009] According to the wind turbine blade provided in the embodiments of this application, the counterweight assembly includes at least two counterweight blocks and a second elastic adhesive layer filled between adjacent counterweight blocks, wherein the second elastic adhesive layer includes an adhesive with a tensile modulus of less than 2 GPa.

[0010] According to the wind turbine blade provided in the embodiments of this application, the first elastic adhesive layer includes an adhesive with a tensile modulus in the range of 0.01 GPa to 1 GPa.

[0011] According to the wind turbine blade provided in the embodiments of this application, the thickness of the first elastic adhesive layer is greater than the thickness of the second elastic adhesive layer.

[0012] According to the wind turbine blade provided in the embodiments of this application, the thickness of the first elastic adhesive layer ranges from 3 mm to 20 mm.

[0013] According to the wind turbine blade provided in the embodiments of this application, the thickness of the second elastic adhesive layer ranges from 2 mm to 5 mm.

[0014] The wind turbine blade provided according to the embodiments of this application further includes a fiber protective layer, which covers the outer surface of the counterweight assembly, and the edge of the fiber protective layer is connected to the blade body.

[0015] According to the wind turbine blade provided in the embodiments of this application, the fiber protective layer includes a biaxial glass fiber fabric, and the angle between the fiber direction of the biaxial glass fiber fabric and the force direction is within the range of ±45 degrees.

[0016] According to the wind turbine blade provided in the embodiments of this application, the blade body includes a stiffening plate placed in the hollow cavity, the stiffening plate is connected between the windward shell and the leeward shell, and the counterweight assembly is installed on the stiffening plate at least away from the leading edge of the blade body.

[0017] According to the wind turbine blade provided in the embodiments of this application, the counterweight assembly is at least installed on the side of the stiffener facing away from the leading edge of the blade body.

[0018] According to the wind turbine blade provided in the embodiments of this application, the counterweight assembly includes a first counterweight layer, a second counterweight layer, and a third elastic adhesive layer stacked along the chordal direction of the wind turbine blade. The first counterweight layer is bonded to the stiffener through the first elastic adhesive layer, and the second counterweight layer is bonded to the side of the first counterweight layer opposite to the stiffener through the third elastic adhesive layer. Both the first counterweight layer and the second counterweight layer include at least two counterweight blocks and the second elastic adhesive layer, and the plurality of counterweight blocks are arranged along a plane perpendicular to the chordal direction.

[0019] The wind turbine blade of this application embodiment has a counterweight assembly installed in the hollow cavity of the blade body. The counterweight assembly is connected to the blade body through a first elastic adhesive layer. The first elastic adhesive layer includes an adhesive with a tensile modulus of less than 2 GPa, which is a low elastic modulus elastic adhesive layer. When the wind turbine blade is subjected to force, the deformation of the counterweight assembly is isolated from the deformation of the blade body through the first elastic adhesive layer. The first elastic adhesive layer has a certain elastic deformation, so the blade body and the counterweight assembly deform independently, avoiding stress concentration and stress accumulation between the counterweight assembly and the blade body, reducing damage between the counterweight assembly and the blade body, and reducing the risk of the counterweight assembly falling off. Attached Figure Description

[0020] 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.

[0021] Figure 1 shows a cross-sectional schematic diagram of a wind turbine blade provided in some embodiments of this application;

[0022] Figure 2 shows a perspective view of a counterweight assembly provided in some embodiments of this application;

[0023] Figure 3 shows a top view of a counterweight assembly with a fiber protective layer provided in some embodiments of this application;

[0024] Figure 4 shows a partial schematic diagram of the counterweight assembly installed on the stiffening plate according to some embodiments of this application;

[0025] Figure 5 shows a partial schematic diagram of the counterweight assembly installed on the stiffening plate according to other embodiments of this application.

[0026] Reference numerals: 100: Blade body; 101: Windward side shell; 102: Leeward side shell; 103: Rib; 200: Counterweight assembly; 201: First counterweight layer; 202: Second counterweight layer; 203: Third elastic adhesive layer; 211: Counterweight block; 212: Second elastic adhesive layer; 220: First elastic adhesive layer; 230: Fiber protective layer. Detailed Implementation

[0027] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0028] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0029] Wind power generation converts the kinetic energy of wind into mechanical kinetic energy, and then into electrical kinetic energy. As a clean energy source, wind power can effectively reduce carbon dioxide emissions, improve energy efficiency, and promote low-carbon development. Wind turbine blades are one of the key components of a generator set that converts wind energy into mechanical energy; a generator set typically consists of three wind turbine blades. When the wind turbine blades reach a certain rotational speed, vibration occurs due to their own structure and the influence of turbulent wind energy, and severe vibration can damage the wind turbine generator set. To prevent excessive blade vibration from damaging the wind turbine generator set, counterweights are installed on the wind turbine blades to control and reduce vibration levels. These counterweights are implemented using counterweight blocks, typically added at the blade's center of gravity, reducing the difference in weight and moment of mass between the three blades, improving dynamic balance during operation, and enhancing the stability of the wind turbine.

[0030] The existing technology involves bonding a single counterweight to the wind turbine blade using a molding compound with a high tensile modulus (2GPa-3GPa). When the wind turbine blade is subjected to load and deforms, stress concentration will occur between the counterweight and the wind turbine blade, which will lead to damage or even cause the counterweight to fall off.

[0031] To address the problems of the prior art, this application provides a wind turbine blade. The wind turbine blade provided in this application is described below.

[0032] Figure 1 shows a cross-sectional schematic diagram of a wind turbine blade provided in some embodiments of this application.

[0033] As shown in Figure 1, this application embodiment provides a wind turbine blade, including: a blade body 100, a counterweight assembly 200, and a first elastic adhesive layer 220. The blade body 100 includes a windward shell 101, a leeward shell 102, and a hollow cavity formed by the windward shell 101 and the leeward shell 102. The counterweight assembly 200 is installed in the hollow cavity of the blade body 100. The counterweight assembly 200 is connected to the blade body 100 through the first elastic adhesive layer 220, which includes an adhesive with a tensile modulus of less than 2 GPa. The deformation of the counterweight assembly 200 is isolated from the deformation of the blade body 100 through the first elastic adhesive layer 220, so that the counterweight assembly 200 and the blade body 100 can deform independently.

[0034] The windward shell 101 is the outer casing of the blade facing the airflow (or wind). In a wind turbine, the windward shell 101 is directly impacted by the wind and must therefore be designed to be sufficiently robust to withstand the pressure and power generated by the wind. The leeward shell 102 is opposite the windward shell 101, located on the back side of the blade, i.e., the side away from the airflow. The space formed by the windward shell 101 and the leeward shell 102 is called a hollow cavity. The hollow cavity can significantly reduce the overall weight of the blade, thereby improving its efficiency and performance. The hollow cavity may include stiffeners or other structural elements to enhance the rigidity and stability of the blade. The hollow cavity can also be used for thermal management (such as heat dissipation) or sound insulation (such as reducing noise transmission).

[0035] Installing the counterweight assembly 200 inside the hollow cavity protects it from the harsh environment that could affect its lifespan and balance accuracy. Furthermore, placing the counterweight assembly 200 inside the hollow cavity facilitates installation, and even if it falls off, it can be caught by the windward and leeward housings 101 and 102, preventing it from falling from a height and increasing the risk to the wind turbine blades.

[0036] The counterweight assembly 200 is connected to the blade body 100 via a first elastic adhesive layer 220, thereby avoiding structural damage caused by fixing methods such as drilling holes in the blade body 100 and ensuring the structural integrity of the blade body 100. Furthermore, the first elastic adhesive layer 220 has advantages such as high connection strength, light weight, and good corrosion resistance. The adhesive method also has a certain buffering and shock absorption effect, helping to protect the blade body 100 and the counterweight assembly 200.

[0037] The first elastic adhesive layer 220 comprises an adhesive with a tensile modulus of less than 2 GPa, i.e., the first elastic adhesive layer 220 comprises an adhesive with a low tensile modulus. Tensile modulus is the ratio of normal stress to corresponding normal strain within the elastic deformation range of a material, reflecting the material's ability to resist tensile deformation. An adhesive with a tensile modulus of less than 2 GPa has high flexibility and elasticity, enabling it to better adapt to minute deformations and displacements between the blade body 100 and the counterweight assembly 200. When the wind turbine blade is under stress, the deformation of the counterweight assembly 200 is isolated from the deformation of the blade body 100 through the first elastic adhesive layer 220, allowing the counterweight assembly 200 and the blade body 100 to deform independently, avoiding stress concentration and stress accumulation. No stress concentration occurs around the counterweight assembly 200, thereby improving the connection stability and impact resistance between the counterweight assembly 200 and the blade body 100.

[0038] The adhesive can be made of materials such as epoxy, polyurethane, and acrylic. Taking polyurethane adhesive as an example, it can include components A and B, which are mixed evenly during use; it can also be multi-component or even single-component.

[0039] Regarding the AB component, component A is the main agent, and component B is isocyanate, also known as the curing agent component. The curing agent used (component B) is polyphenyl polyisocyanate, MDI, IPDI or a mixture thereof. The curing agent may also partially use dimers, trimers, and prepolymers of polyols with MDI, trimers and prepolymers of polyols with TDI, trimers of HDI, mixed trimers of HDI and TDI, and prepolymers of HDI and polyols.

[0040] For single-component cases: Component A used is mainly composed of polyhydroxy compounds, which can be hydroxyl-terminated polyethers, hydroxyl-terminated polyesters, and all compounds containing multiple hydroxyl groups; the average molecular weight is in the range of 200 to 5000, the viscosity at 25°C is less than 20000 mPa·sec, and the average functionality is 2 to 10.

[0041] Furthermore, in this embodiment, the first elastic adhesive layer 220 comprises an adhesive with a tensile modulus ranging from 0.01 GPa to 1 GPa. At room temperature (approximately 23°C), the tensile modulus of the adhesive is 0.01 GPa to 1 GPa; when the modulus is 0.001 GPa to 0.1 GPa, the first elastic adhesive layer 220 exhibits a better effect in reducing stress concentration. When the modulus of the first elastic adhesive layer 220 is 0.001 GPa to 0.1 GPa, its effect in reducing stress concentration is even better. With a tensile modulus of 0.01 GPa to 1 GPa, the adhesive layer possesses high elasticity and flexibility, allowing for greater deformation.

[0042] Referring again to FIG1, in an optional embodiment of this application, the blade body 100 includes a stiffener 103 disposed in a hollow cavity. The stiffener 103 is connected between the windward shell 101 and the leeward shell 102. The counterweight assembly 200 is installed on the stiffener 103 at least away from the leading edge of the blade body 100.

[0043] The stiffening rib 103 connects the windward shell 101 and the leeward shell 102. The stiffening rib 103 provides additional support to the wind turbine blades, effectively resisting various bending, torsional, and tensile stresses borne by the blades under wind force. This prevents the wind turbine blades from deforming easily in harsh environments such as strong winds, maintaining a stable shape and structure, ensuring normal operation and efficient conversion of wind energy into mechanical energy. Furthermore, it enhances the bending resistance of the wind turbine blades, preventing excessive bending due to their own weight and wind force, thereby extending the blades' service life.

[0044] At least two stiffeners 103 are radially distributed within the hollow cavity of the wind turbine blade. The counterweight assembly 200 is installed on at least one stiffener 103 located away from the leading edge of the blade body 100. The stiffener 103 is I-shaped and has a straight section that facilitates the installation of the counterweight assembly 200. Furthermore, the structure of the counterweight assembly 200 can be more regular, for example, it can be a rectangular block, which facilitates the production of the counterweight assembly 200 and the precise control of its weight.

[0045] In another alternative embodiment of this application, the counterweight assembly 200 is at least installed on the side of the stiffener 103 facing away from the leading edge of the blade body 100. That is, the counterweight assembly 200 is located near the trailing edge.

[0046] The counterweight assembly 200, located near the trailing edge, adjusts the lift distribution of the wind turbine blades. During the rotation of the wind turbine blades, different parts generate varying levels of lift. The counterweight assembly 200 near the trailing edge allows for fine-tuning of the aerodynamic shape of the blades, resulting in a more uniform lift distribution and improved wind energy conversion efficiency. A well-balanced lift distribution helps reduce airflow separation on the blade surface, lowering aerodynamic drag and thus enhancing the overall performance of the wind turbine generator.

[0047] Wind forces acting on wind turbine blades cause torsional and bending deformations. Placing the counterweight assembly 200 near the trailing edge can, to some extent, balance the torsional moment of the wind turbine blades under different wind speeds, reducing the degree of blade twisting. The counterweight assembly 200 near the trailing edge can also suppress the bending deformation of the wind turbine blades, allowing them to maintain a relatively stable shape during operation and reducing structural damage and performance degradation caused by excessive deformation.

[0048] Wind turbine blades are typically long and slender, and the position of their center of gravity significantly impacts their stability and dynamic response. Placing the counterweight assembly 200 near the trailing edge lowers the overall center of gravity of the blade, improving its stability. A lower center of gravity makes the wind turbine blade more stable during rotation and under wind loads, reducing swaying and vibration, and lowering the risk of structural fatigue.

[0049] Figure 2 shows a perspective view of a counterweight assembly 200 provided in some embodiments of this application; Figure 3 shows a top view of a counterweight assembly 200 with a fiber protective layer 230 provided in some embodiments of this application; Figure 4 shows a partial schematic diagram of a counterweight assembly 200 provided in some embodiments of this application installed on a stiffening plate 103.

[0050] As shown in Figures 2 to 4, in other embodiments of this application, the wind turbine blade further includes a fiber protective layer 230, which covers the outer surface of the counterweight assembly 200, and the edge of the fiber protective layer 230 is connected to the blade body 100.

[0051] The fiber protective layer 230 securely wraps the counterweight assembly 200 around the blade body 100, preventing displacement of the counterweight assembly 200 during blade rotation and vibration. It limits the position of the counterweight assembly 200, maintaining its stability and ensuring the balance and stability of the wind turbine blade. A stable counterweight assembly 200 helps improve the aerodynamic performance and structural strength of the wind turbine blade, and reduces vibration and noise caused by its movement.

[0052] When the wind turbine blade is subjected to wind force or other external forces, the resulting stress is transmitted to the counterweight assembly 200 through the fiber protective layer 230. The fiber protective layer 230 can evenly distribute these stresses, preventing stress concentration in localized areas of the counterweight assembly 200, thereby reducing the risk of damage to the counterweight assembly 200. At the same time, the fiber protective layer 230 itself also has a certain tensile strength and toughness, which can withstand part of the stress, sharing the external force with the blade body 100 and improving the reliability of the entire wind turbine blade structure.

[0053] The fiber protective layer 230 is made of biaxial glass fiber fabric or organic fiber fabric, and the organic fiber fabric can be made of nylon fiber fabric, acrylic fiber fabric or polyester fiber fabric. The fiber protective layer 230 can reduce the modulus of the counterweight component 200.

[0054] Furthermore, in an optional embodiment of this application, the fiber protective layer comprises a biaxial glass fiber fabric, wherein the angle between the fiber direction of the biaxial glass fiber fabric and the direction of force is within ±45 degrees. This can reduce the modulus of the counterweight component 200 in the 90° direction.

[0055] The angle between the fiber direction and the direction of force is within ±45 degrees, allowing the fibers of the fiber protective layer 230 to simultaneously bear component forces from different directions. This prevents stress concentration in a single direction, dispersing the stress among the fibers of the fiber protective layer 230. For the counterweight component 200, stress dispersion reduces the concentrated stress it experiences in the 90° direction, thereby improving the overall structural stability and reliability.

[0056] For example, the fiber protective layer 230 comprises a biaxial glass fiber fabric with a fiber orientation of ±45°, such that the angle between the fiber orientation and the direction of force is within ±45 degrees. When subjected to external force, the fiber protective layer 230 provides a certain buffer space in the direction perpendicular to the fiber protective layer 230. This can reduce stress concentration and potential damage caused by excessive rigidity.

[0057] Referring again to Figures 2 and 4, in other embodiments of this application, the counterweight assembly 200 includes at least two counterweight blocks 211 and a second elastic adhesive layer 212 filled between adjacent counterweight blocks 211, the second elastic adhesive layer 212 including an adhesive with a tensile modulus of less than 2 GPa.

[0058] In other words, the counterweight assembly 200 includes multiple counterweight blocks 211. When subjected to external forces, each counterweight block 211 deforms independently, avoiding stress concentration and stress accumulation. For example, when a wind turbine blade is subjected to wind impact or vibration, the counterweight blocks 211 at different locations will deform according to the direction and magnitude of the external force. This independent deformation characteristic prevents stress from concentrating at a specific point, thereby reducing the risk of structural damage due to excessive local stress.

[0059] A low-modulus second elastic adhesive layer 212 connects multiple counterweights 211. When the multiple counterweights 211 are subjected to external force, the second elastic adhesive allows each counterweight 211 to respond independently to the external force, without transmitting stress to adjacent counterweights 211, and maintaining overall connectivity. This avoids stress accumulation throughout the entire counterweight assembly 200, ensuring that the stress borne by each counterweight 211 remains at a relatively low level. The adhesive of the second elastic adhesive layer 212 can include materials such as epoxy, polyurethane, and acrylic. Taking polyurethane adhesive as an example, it can include components A and B, which are mixed evenly during use; it can also be multi-component or even single-component.

[0060] Figure 5 shows a partial schematic diagram of the counterweight assembly 200 installed on the stiffening plate 103 according to other embodiments of this application.

[0061] As shown in Figure 5, in some other embodiments of this application, the counterweight assembly 200 includes a first counterweight layer 201, a second counterweight layer 202, and a third elastic adhesive layer 203 stacked along the chordal direction of the wind turbine blade. The first counterweight layer 201 is bonded to the stiffener 103 through the first elastic adhesive layer 220, and the second counterweight layer 202 is bonded to the side of the first counterweight layer 201 away from the stiffener 103 through the third elastic adhesive layer 203. Both the first counterweight layer 201 and the second counterweight layer 202 include at least two counterweight blocks 211 and a second elastic adhesive layer 212. The multiple counterweight blocks 211 are arranged along a plane perpendicular to the chordal direction.

[0062] The third elastic adhesive layer 203 includes an adhesive with a tensile modulus of less than 2 GPa. The adhesive of the third elastic adhesive layer 203 may include materials such as epoxy, polyurethane, and acrylic. Taking polyurethane adhesive as an example, it may include components A and B, which are mixed evenly during use; it may also be multi-component or even single-component. The counterweight 211 may be made of metal or high-density rubber.

[0063] To increase the weight of the counterweight assembly 200, multiple counterweight layers can be provided. The second counterweight layer 202 is bonded to the side of the first counterweight layer 201 facing away from the stiffener 103 via a third elastic adhesive layer 203. The second counterweight layer 202 may include multiple counterweight layers stacked along the chord direction, connected by the third elastic adhesive layer 203. Each counterweight layer includes multiple counterweight blocks 211, connected by a second elastic adhesive layer 212. The number of counterweight blocks 211 in each counterweight layer can be the same or different. The mass and size of the counterweight blocks 211 in each layer can be the same or different.

[0064] In addition, in the embodiments of this application, the thickness of the first elastic adhesive layer 220 is greater than the thickness of the second elastic adhesive layer 212.

[0065] The thicker first elastic adhesive layer 220 allows for a better and more secure connection with the blade body 100. Furthermore, the first elastic adhesive layer 220 receives the stress transmitted from the blade body 100 first and experiences the greatest stress; the thicker first elastic adhesive layer 220 can withstand greater loads without detaching. The second elastic adhesive layer 212 is used to connect the counterweight 211. Since the counterweight 211 has a smaller mass, a relatively thinner adhesive can be used to achieve a stable connection, ensuring the counterweight assembly 200 has a large mass within a small volume.

[0066] Furthermore, in this embodiment, the thickness of the first elastic adhesive layer 220 ranges from 3 mm to 20 mm.

[0067] In another embodiment of this application, the thickness of the second elastic adhesive layer 212 ranges from 2 mm to 5 mm.

[0068] 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, wherein, include: The blade body includes a windward shell, a leeward shell, and a hollow cavity formed by the windward shell and the leeward shell. A counterweight assembly, wherein the counterweight assembly is installed in the hollow cavity of the blade body; A first elastic adhesive layer is provided, through which the counterweight assembly is connected to the blade body. The first elastic adhesive layer comprises an adhesive with a tensile modulus of less than 2 GPa. The deformation of the counterweight assembly is isolated from the deformation of the blade body through the first elastic adhesive layer, so that the counterweight assembly and the blade body can deform independently.

2. The wind turbine blade according to claim 1, wherein, The counterweight assembly includes at least two counterweight blocks and a second elastic adhesive layer filled between adjacent counterweight blocks, the second elastic adhesive layer comprising an adhesive with a tensile modulus of less than 2 GPa.

3. The wind turbine blade according to claim 1, wherein, The first elastic adhesive layer comprises an adhesive with a tensile modulus in the range of 0.01 GPa to 1 GPa.

4. The wind turbine blade according to claim 2, wherein, The thickness of the first elastic adhesive layer is greater than the thickness of the second elastic adhesive layer.

5. The wind turbine blade according to claim 4, wherein, The thickness of the first elastic adhesive layer ranges from 3 mm to 20 mm.

6. The wind turbine blade according to claim 4, wherein, The thickness of the second elastic adhesive layer ranges from 2 mm to 5 mm.

7. The wind turbine blade according to any one of claims 1 to 6, wherein, It also includes a fiber protective layer that covers the outer surface of the counterweight assembly, and the edge of the fiber protective layer is connected to the blade body.

8. The wind turbine blade according to claim 7, wherein, The fiber protective layer includes a biaxial glass fiber fabric, wherein the angle between the fiber direction and the stress direction of the biaxial glass fiber fabric is within ±45 degrees.

9. The wind turbine blade according to claim 2, wherein, The blade body includes a stiffening plate placed in the hollow cavity, the stiffening plate being connected between the windward shell and the leeward shell, and the counterweight assembly being installed at least on the stiffening plate away from the leading edge of the blade body.

10. The wind turbine blade according to claim 9, wherein, The counterweight assembly is installed at least on the side of the stiffener facing away from the leading edge of the blade body.

11. The wind turbine blade according to claim 9, wherein, The counterweight assembly includes a first counterweight layer, a second counterweight layer, and a third elastic adhesive layer stacked along the chord length direction of the wind turbine blade. The first counterweight layer is bonded to the stiffening plate through the first elastic adhesive layer, and the second counterweight layer is bonded to the side of the first counterweight layer opposite to the stiffening plate through the third elastic adhesive layer. Both the first and second counterweight layers include at least two counterweight blocks and the second elastic adhesive layer, and the plurality of counterweight blocks are arranged along a plane perpendicular to the chord length direction.

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