Composite wind turbine blade

Abstract

The utility model relates to the technical field of wind driven generator blade, the utility model provides a kind of composite wind driven generator blade, support grid layer both sides are equipped with fibre resin layer, to constitute composite blade. By the above technical scheme, outer fibre layer is responsible for aerodynamic shape and environmental protection, middle metal layer is responsible for rigidity and mechanical reinforcement, inner fibre layer is responsible for internal stability and auxiliary force transmission, the reliable connection of three;Further in practical application, it can be adapted to different scenarios, both retain the advantage of "low cost, easy to manufacture", and can be targeted to improve anti-aging, anti-tear and other properties, provide flexible and high cost-effective solution for small and medium-sized wind driven generator blade.

Description

Technical Field

[0001] The embodiments of this utility model relate to the field of wind turbine blade technology, specifically to a composite wind turbine blade. Background Technology

[0002] Wind turbine blades are the core components that convert wind energy into mechanical energy. Due to their harsh environment and continuous operation, they are required to have excellent properties such as light weight, fatigue resistance, corrosion resistance, UV resistance, and lightning strike resistance. They also require low installation and maintenance costs. Their design, materials, and performance directly determine the power generation efficiency, reliability, and economy of the wind power generation system.

[0003] The most common structure is made of glass fiber or carbon fiber reinforced plastic (GFRP or CFRP). The fiber reinforcement provides high strength and high modulus, while the resin matrix plays the role of fixing the fibers, transferring loads and protecting the fibers. This structure can meet different mechanical performance requirements by adjusting the fiber layup direction and number of layers. For example, in the main spars part of the blade, the thickness and number of carbon fiber layers can be increased to improve the bending strength of the blade.

[0004] However, the above structure has the following drawbacks: the overall structure is relatively complex, it is not easy to manufacture, and it needs further optimization in terms of weight and anti-aging properties. Utility Model Content

[0005] To overcome the above-mentioned defects, the embodiments of this utility model provide a composite wind turbine blade, which solves the technical problems in the related technology that the overall structure of wind turbine blades is relatively complex, not easy to manufacture, and requires further optimization in terms of weight and anti-aging properties.

[0006] According to one aspect, at least one embodiment of the present invention provides a composite wind turbine blade, comprising: A supporting grid layer is provided, with fiber resin layers on both sides of the supporting grid layer to form a composite blade.

[0007] For example, at least one embodiment of this utility model provides a composite wind turbine blade, wherein the fiber resin layer is a glass fiber layer.

[0008] For example, at least one embodiment of this utility model provides a composite wind turbine blade, wherein the fiber resin layer is a basalt fiber layer.

[0009] For example, at least one embodiment of this utility model provides a composite wind turbine blade, wherein the fiber resin layer is a carbon fiber layer.

[0010] For example, at least one embodiment of this utility model provides a composite wind turbine blade, wherein the supporting mesh layer is a metal alloy mesh layer.

[0011] For example, at least one embodiment of this utility model provides a composite wind turbine blade, wherein the supporting mesh layer is a metal wire mesh layer.

[0012] For example, at least one embodiment of this utility model provides a composite wind turbine blade, wherein the supporting grid layer is a metal plate layer.

[0013] For example, at least one embodiment of this utility model provides a composite wind turbine blade, wherein the supporting grid layer is corrugated to form a hollow vacuum insulation panel.

[0014] For example, at least one embodiment of this utility model provides a composite wind turbine blade, wherein the supporting grid layer is a flat plate or an arc-shaped plate, and the fiber resin layer is a flat plate or an arc-shaped plate.

[0015] For example, at least one embodiment of this utility model provides a composite wind turbine blade, wherein the supporting grid layer is a serrated plate or a hollow plate.

[0016] The beneficial effects of the embodiments of this utility model are as follows: First, a lightweight design combining high-strength materials and low density is employed to reduce weight. Specifically, the inner and outer fiber resin layers form the basis for lightweighting. The glass fiber, basalt fiber, and carbon fiber used are all low-density, high-strength materials (glass fiber density is approximately 25 g / cm³). 3 Basalt fiber: approximately 26 g / cm³ 3 Carbon fiber is only 17g / cm³ 3 The aluminum alloy has a weight of approximately 27g / cm³, which is significantly lower than that of traditional metal blades. 3 Steel is approximately 78g / cm³. 3 The middle metal mesh layer (aluminum alloy / steel wire) has a hollow structure, which can reduce the amount of metal used by 50% to 70% compared with solid metal plates. The corrugated structure can strengthen the blade's strength and bending resistance through its concave and convex shape.

[0017] Secondly, the blade consists of three independent functional layers. The outer / inner fiber resin layers can be manufactured using a mature vacuum-assisted molding process, while the middle metal mesh layer is a prefabricated component (aluminum alloy / steel wire mesh can be manufactured using industrial stamping and weaving, and corrugated metal sheet structures can be processed using a bending machine). When assembling the three layers, there is no need for complex splicing procedures; it is only necessary to lay the layers in sequence for curing, and finally refine the shape and conduct various tests. During the curing process, there is no need for additional welding or bolt connections, which reduces manufacturing steps. Furthermore, the rigidity of the metal mesh can serve as a "support skeleton" for the fiber layup, preventing wrinkles during fiber cloth laying and reducing the difficulty of manual operation.

[0018] Meanwhile, the outer fiber resin layer is in direct contact with the atmospheric environment. Glass fiber and basalt fiber themselves have excellent weather resistance, and the resin matrix can be supplemented with anti-ultraviolet agents and antioxidants to form a composite barrier of "fiber reinforcement + resin protection" to block ultraviolet rays, rainwater and salt spray from corroding the inside of the blade. In addition, the inner fiber resin layer can isolate water vapor that may be generated inside the blade (such as condensation caused by temperature difference), preventing the middle metal mesh layer from rusting due to internal moisture, and further extending the overall lifespan.

[0019] Regarding tear resistance, the inner and outer fiber resin layers can effectively resist the "tensile tearing" of the blade under wind load. When the blade is subjected to wind force and tends to tear locally, the continuous fibers can distribute the load to the entire fiber layer, preventing crack propagation. Furthermore, the "node connections" of the middle metal mesh layer (such as the welded nodes of the aluminum alloy mesh and the woven nodes of the steel wire mesh) can withstand high shear strength, making up for the shortcomings of the fiber resin layer. If a corrugated metal plate is used, the "edges" of the corrugations can further enhance the shear resistance.

[0020] In summary, the outer fiber layer is responsible for aerodynamic shape and environmental protection, the middle metal layer is responsible for stiffness and mechanical reinforcement, and the inner fiber layer is responsible for internal stability and auxiliary force transmission. The three are reliably connected. Therefore, in practical applications, it can be adapted to different scenarios, retaining the advantages of "low cost and easy manufacturing" while specifically improving anti-aging and tear resistance, providing a flexible and cost-effective solution for small and medium-sized wind turbine blades. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are merely some exemplary embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the content of the exemplary embodiments of this utility model and these drawings without any creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of a composite wind turbine blade in one embodiment of the present invention; Figure 2 for Figure 1 Exploded view; Figure 3 for Figure 1 A schematic diagram of the structure supporting the mesh layer in the embodiment; Figure 4 This is an exploded view of a composite wind turbine blade in another embodiment of the present invention. Figure 5 for Figure 4 The embodiment shows a schematic diagram of the structure supporting the mesh layer.

[0023] In the diagram: 1. Supporting mesh layer; 2. Fiber resin layer. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit its scope.

[0025] To keep the drawings concise, each drawing only schematically shows the parts relevant to the disclosure; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0026] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are 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. Therefore, they should not be construed as limitations on this utility model.

[0029] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] In rural / remote areas and coastal regions with high salinity and humidity, wind speeds fluctuate significantly. Small to medium-sized wind turbines are typically installed, generating electricity through "energy capture, transfer, and conversion." First, when the ambient wind speed reaches the cut-in wind speed (usually 3 m / s), the blades, driven by the wind, rotate the hub, converting wind energy into mechanical rotational energy between the blades and the hub. Then, the hub, connected to a speed-increasing gearbox via the main shaft, converts low-speed rotation into high-speed rotation. The high-speed rotating main shaft then drives the generator (mostly a permanent magnet synchronous generator), converting mechanical energy into alternating current (AC), which is then rectified into direct current (DC) and adjusted by an inverter to AC (220V / 380V, 50Hz) that meets grid standards, before being connected to the industrial park's power grid or directly supplied to factories. (Throughout the process, if the wind speed exceeds the cut-out wind speed, the pitch system adjusts the blade angle to reduce the rotational speed, thus protecting the unit's safety.)

[0031] Composite blades serve as the core, such as Figures 1-3 As shown, this invention illustrates a composite wind turbine blade in one embodiment, comprising a supporting mesh layer 1 and fiber resin layers 2 on both sides thereon to form a composite blade. Specifically, the supporting mesh layer 1 serves as the load-bearing core of the blade. First, the "lightweight support" is fabricated and placed in the middle using components such as an overhead crane or workbench. Then, a substrate is wrapped around it and cured (the substrate refers to the inner and outer fiber resin layers 2, such as PVC, resin, fiberglass, basalt fiber, or other reinforcing fibers). The bonding method for the substrate can be adhesive bonding, molding, or extrusion. For example, PVC or resin substrates are used for molding, while resin bonding is used when forming the blade using extrusion or other molding processes.

[0032] Furthermore, the surface of the support grid layer 1 can be pretreated by "roughening + activation". Sandpaper can be used to remove the surface oxide film, and then a coupling agent can be sprayed to enhance the adhesion between the resin and the metal. When covering the substrate, a layer of resin can be applied to both sides of the support grid layer 1 first. After the resin penetrates into the hollow space of the support grid layer 1 (forming resin pillars), the resin can be poured in as a whole.

[0033] Subsequently, the product is cured and shaped in a continuous curing oven. After molding, the finished product is externally modified by grinding, polishing or sandblasting to form the desired shape, such as a flat or curved shape. Finally, weight testing or bending resistance testing is performed.

[0034] Meanwhile, the supporting mesh layer 1 can be one of a metal alloy mesh layer, a metal wire mesh layer, or a metal plate layer, and is bent to form an uneven structure to enhance the blade's strength and resistance to bending disturbances. Figure 3As shown, it is a metal plate with several weight-reducing holes on its surface. These holes can be arranged in a matrix or other forms. The shape of the weight-reducing holes is not always a regular square or other shape; they can also be parallelograms or other shapes. This will not be discussed in detail here.

[0035] Alternatively, titanium alloy mesh can be used, which has extremely strong corrosion resistance, requires no additional coating on the surface, and can be directly connected to the outer / inner fiber layer. The mesh nodes are laser welded, and compared with aluminum alloy mesh, its service life is increased by more than 3 times, making it more suitable for intertidal wind power projects. Alternatively, copper alloy mesh can be used, which has good conductivity and can be connected to the grounding device to form a "built-in lightning protection network". When the blade is struck by lightning, the brass mesh can quickly conduct the lightning current to the ground, preventing the outer fiber layer from being broken down, making it more suitable for areas with heavy rainfall and lightning.

[0036] In summary, this composite wind turbine blade, through the synergy of "supporting grid layer 1 + double-sided fiber resin layer 2", precisely adapts to the usage scenarios of small and medium-sized units, thus being adaptable to different scenarios. It retains the advantages of "low cost and easy manufacturing" while also specifically improving performance such as anti-aging and tear resistance, providing a flexible and cost-effective solution for small and medium-sized wind turbine blades.

[0037] Furthermore, regarding the selection of the inner and outer fiber resin layers 2, the following materials can also be used: aramid fiber, which has high impact strength (approximately 2100 MPa), suitable for windy and sandy areas (such as northwest wind power); a hybrid fabric of "glass fiber + aramid fiber" can be laid on the leading edge of the blade (the part most severely impacted by wind and sand), while the rest of the parts still use glass fiber, which improves impact resistance and controls costs; another example is carbon fiber combined with phenolic resin, which can improve high-temperature resistance (long-term operating temperature above 200℃), suitable for high-temperature areas (such as the summer sun exposure environment in the south), and can be laid on the upper surface of the blade (the side directly exposed to sunlight) to prevent the resin from softening due to high temperatures; yet another example is glass fiber combined with polyurethane resin, which improves elasticity (elongation at break of approximately 8%), making it more suitable for cold northern regions. The inner fiber layer uses glass fiber cloth, and the resin uses polyurethane resin (which has stable elastic modulus at low temperatures and does not become brittle), isolating the condensate inside the blade and preventing the middle metal layer from rusting due to low temperature and humidity.

[0038] As a further implementation method, such as Figure 4 , Figure 5 As shown, the support grid layer 1 can be bent into a corrugated shape using a bending machine to form a hollow vacuum insulation board, enhancing the overall unevenness and strengthening the blade. Specifically, the support grid layer 1 presents an undulating shape similar to corrugated waves, composed of multiple continuous peaks and troughs alternating. From the cross-section of the blade, it resembles a repeated "M" or "W" shape. Along the length of the blade, this corrugated structure extends continuously, penetrating the entire middle area of ​​the blade.

[0039] The corrugated structure can significantly improve the bending and torsional resistance of the supporting grid layer 1 without significantly increasing the amount of material used. This is because the corrugated shape increases the moment of inertia of the structure, which can more effectively resist deformation when subjected to bending loads and torques generated by wind. This ensures that the blade maintains a stable shape and performance under complex wind conditions and extends the service life of the blade. Moreover, compared with a solid supporting structure, the corrugated structure has a large number of hollow spaces inside, which reduces the amount of material used and thus reduces the overall weight of the blade, while also making it easier to manufacture.

[0040] Similarly, the supporting grid layer 1 can also be made into a serrated plate or a hollow plate. For the serrated plate, it is bonded to the outer / inner fiber layer, which does not affect the aerodynamic shape and can destroy the wake vortex through the serrations to reduce noise. The hollow plate is similar and the structure is simple to manufacture. The outer / inner fiber layer is flat, and the middle metal layer adopts a honeycomb metal grid, forming a "flat airfoil". It can be quickly manufactured by manual layering, which is suitable for the low cost and small size requirements of small units and also has a certain weight reduction effect.

[0041] As a further implementation, both the supporting mesh layer 1 and the fiber resin layer 2 can be made into flat plates or curved plates. Flat plates have already been discussed above and will not be elaborated on here. The advantage of curved plates is that they can efficiently capture wind energy and reduce airflow resistance. They can be made into curved plates similar to "hooks". Specifically, when the wind blows towards the blade, the upper and lower surfaces of the curved plate will form different airflow speeds and pressure distributions, thereby generating upward lift and rotational torque, driving the blade to rotate, effectively improving the wind energy capture efficiency, providing a power basis for the wind turbine to convert wind energy into mechanical energy, and making the airflow more closely follow the blade surface, reducing the generation of turbulence and vortices, reducing air resistance, and making the blade more efficient and stable during rotation.

[0042] Meanwhile, the arc shape facilitates composite molding with the corrugated support grid layer 1. During the manufacturing process, the arc plate can fit the shape of the support grid layer 1 well, and achieve integrated connection through bonding and other processes, ensuring the integrity of the blade structure and manufacturing quality, and also facilitating subsequent installation and maintenance.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A composite wind turbine blade, characterized in that, include: A supporting grid layer (1) is provided on both sides of the supporting grid layer (1) to form a composite blade; The supporting grid layer (1) is corrugated to form a hollow vacuum insulation board.

2. The composite wind turbine blade according to claim 1, characterized in that, The fiber resin layer (2) is a glass fiber layer.

3. The composite wind turbine blade according to claim 1, characterized in that, The fiber resin layer (2) is a basalt fiber layer.

4. The composite wind turbine blade according to claim 1, characterized in that, The fiber resin layer (2) is a carbon fiber layer.

5. A composite wind turbine blade according to any one of claims 1 to 4, characterized in that, The supporting mesh layer (1) is a metal alloy mesh layer.

6. A composite wind turbine blade according to any one of claims 1 to 4, characterized in that, The supporting mesh layer (1) is a metal wire mesh layer.

7. A composite wind turbine blade according to any one of claims 1 to 4, characterized in that, The supporting grid layer (1) is a metal plate layer.

8. A composite wind turbine blade according to claim 1, characterized in that, The supporting grid layer (1) is a flat plate or an arc-shaped plate, and the fiber resin layer (2) is a flat plate or an arc-shaped plate.

9. A composite wind turbine blade according to any one of claims 1 to 4, characterized in that, The supporting grid layer (1) is a sawtooth plate or a hollow plate.

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