Wind power blade structure containing double-sided mold closing PVC (polyvinyl chloride)
By setting up double-sided clamping PVC and multi-layer bidirectional cloth on the pressure and suction surfaces of wind power blades, the problems of uneven cloth sliding and resin distribution are solved, and more efficient production and a stronger blade structure are achieved, reducing the Material cost and production complexity.
Patent Information
- Application Number
- CN202421031584.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-13
- Publication Date
- 2024-12-17
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
During the manufacturing process of wind power blades, the laying efficiency of the cloth layer on the vertical edge of the pressure surface of the composite film PVC is low, the cloth layer is easy to slide, and the cloth layer at the corner position does not follow the shape during the insulating process, resulting in the corner overflow of resin and the folds of the vertical edge cloth layer. The structural glue of the mold joint is super thick, which increases the risk during the operation of the blade.
The double-sided mold clamping PVC structure is adopted, which includes the mold clamping PVC on the pressure surface and the suction surface respectively, and a multi-layer bidirectional cloth is set on both sides. The rigidity and shape of the PVC are fixed to reduce the use of spraying glue and ensure uniform distribution and integration of resins. Control of the thickness of mold joint structure glue.
It improves the fixity of the fabric layer and the uniformity of the resin distribution, reduces material costs and production complexity, shortens the production cycle, enhances the structural integrity and durability of the blades, and improves market adaptability and competitiveness.
Smart Images
Figure CN222185000U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of wind power blade structures, in particular to a wind power blade structure containing double-sided molded PVC. Background Art
[0002] As an important component of clean energy, wind power generation plays an increasingly important role in addressing the global energy crisis and climate change. As a key component of wind turbine generators, the performance of wind turbine blades directly affects the efficiency and cost of wind power generation. With the rapid development of wind power technology, the large-scale, lightweight, high-strength and long-life blades have become a hot topic of research.
[0003] In the design and manufacturing process of wind turbine blades, the blunt trailing edge shape is widely adopted because of its significant advantages in improving aerodynamic efficiency and enhancing structural strength. This design helps to reduce vortex shedding when the blades rotate, thereby reducing noise and improving energy conversion efficiency. At the same time, the blunt trailing edge shape also helps to improve the structural stability of the blades, especially in the face of complex wind conditions.
[0004] The manufacturing process of blades is complex and delicate, involving several key steps. First, skin layup is the first step in blade manufacturing, usually using high-performance fiber materials such as glass fiber or carbon fiber to ensure that the blade has sufficient strength and stiffness. The quality of the skin directly affects the overall performance of the blade, so the fiber arrangement, tension and resin distribution during the layup process need to be strictly controlled. Moulding is another key step in the manufacturing process, which involves combining the molds of the two half shells to form the final shape of the blade. The use of molded PVC (polyvinyl chloride) is crucial in this process. As a composite material, PVC not only provides additional structural strength, but also helps to improve the durability and fatigue resistance of the blade. During the layup of the suction side, the molded PVC is sucked and injected with the skin material as a whole, ensuring a good bond between the materials and overall performance. Resin injection is the final stage of blade manufacturing, which involves injecting resin into the laid fiber cloth layer. This step is crucial to the final performance of the blade because the resin not only plays a role in bonding the fibers, but also provides additional stiffness and strength to the blade. During the injection process, the flow and distribution of the resin need to be precisely controlled to avoid problems such as voids, bubbles, and uneven resin infiltration.
[0005] At present, large-size blades are mainly designed with blunt trailing edges. However, the cloth layer at the corner of the blunt trailing edge of the pressure surface is prone to not following the shape of the blade during the injection process, and the cloth layer on the vertical edge is prone to slide down, resulting in defects such as resin overflow at the corner of the pressure surface and excessive thickness of the structural glue in the mold seam.
[0006] With the trend of blades becoming larger, higher requirements are placed on the production quality and production cycle of blades. In current manufacturing, the film-coated PVC is generally located on the suction side, and the film-coated PVC and the suction side are injected together; the cloth on the vertical edge of the pressure side is generally fixed by spraying glue to prevent it from sliding down. During the injection process, the cloth at the corner is prone to not follow the shape, and too much spraying glue affects the interlayer performance.
[0007] It can be seen that the current laying efficiency of the fabric layer on the vertical edge of the pressure surface of the PVC film is low, the fabric layer is easy to slide down, and the fabric layer at the corner position does not follow the mold during the suction and injection process. This leads to easy resin overflow at the corner position, wrinkles on the vertical edge fabric layer, and excessive thickness of the structural adhesive at the mold seam position, which increases the risk during the operation of the blade. Summary of the invention
[0008] In order to solve the above problems, the utility model proposes a wind turbine blade structure containing double-sided molded PVC. The blade structure containing double-sided molded PVC is used in production. Compared with the previous molded PVC structure only on the suction side, the newly added pressure side molded PVC can effectively press the cloth layers on the corners and vertical edges, reducing the amount of spray glue used in the vertical edge ply; ensuring that the pressure side corners do not overflow with resin, the cloth layers laid on the vertical edges do not slide down, and the trailing edge molded structure glue is not too thick, thereby improving the efficiency of the shell ply and shortening the blade production cycle.
[0009] The technical solution adopted by the utility model to solve its technical problems is:
[0010] The utility model discloses a wind turbine blade structure containing double-sided molded PVC, comprising:
[0011] The pressure surface mold-fitting PVC, the suction surface mold-fitting PVC, and a multi-layer bidirectional fabric respectively wrapping the pressure surface mold-fitting PVC and the suction surface mold-fitting PVC, wherein the chord-wise end position of the bidirectional fabric is longer than the mold-fitting PVC;
[0012] There are 4 layers of multi-layer bidirectional fabric, which are laid on the suction side and the pressure side respectively; the starting position of the fabric layer in the span direction starts from the PVC starting position and retreats 100mm toward the blade root layer by layer, and the starting position of the fourth fabric layer is 300mm away from the PVC starting position; the ending position starts from the PVC ending position and decreases 100mm toward the blade tip layer by layer, and the 4th layer is 300mm away from the PVC ending position; the fabric layers are staggered 5mm toward the trailing edge layer by layer in the chord direction, and the overall center position of the fabric layer is flush with the parting line.
[0013] Preferably, the inner skin is made of fiber material, including glass fiber or carbon fiber.
[0014] Preferably, the hypotenuse side of the bevel at the starting position of the PVC is chamfered 1:1 in the thickness direction, but not in the span direction.
[0015] Preferably, one side of the outer edge of the multi-layer bidirectional cloth is folded onto the mold-matching PVC surface and fixed by heat pressing or adhesive.
[0016] The utility model has the following advantages compared with the prior art:
[0017] (1) In the traditional wind turbine blade manufacturing process, the fixation of the cloth layer is a challenge, especially in the manufacture of large blades. The cloth layer is easily displaced during the resin injection process, resulting in uneven structure. The utility model sets a molded PVC on the pressure surface and the suction surface, and uses the rigidity and shape of the PVC to pre-fix the cloth layer, effectively preventing the cloth layer from sliding and not following the shape. This fixing method reduces the reliance on additional spraying, thereby reducing the risk of reduced interlayer performance.
[0018] (2) In the laying of the vertical edge fabric layer of a large blade, in order to prevent the fabric layer from sliding down, the traditional process often requires the use of a large amount of spray glue for fixing. This not only increases the material cost, but also too much adhesive may affect the interlayer performance and reduce the durability of the blade. In the utility model, due to the fixing effect of the molded PVC, the amount of spray glue used is greatly reduced, thereby reducing the material cost and improving the interlayer performance.
[0019] (3) During the injection process of the blade, the uniform distribution of the resin is crucial. The resin easily accumulates at the corners of the pressure surface, resulting in the problem of overflow, which not only wastes materials but may also cause internal defects after curing. The utility model effectively guides the resin flow by precisely controlling the position and shape of the molded PVC, prevents the resin from overflowing at the corners, and ensures the uniform distribution of the resin throughout the blade structure.
[0020] (4) The production efficiency of wind turbine blades directly affects the manufacturing cost and market competitiveness. The utility model reduces the complexity and uncertainty in production by simplifying the cloth layer laying and fixing steps, thereby significantly improving production efficiency. In addition, reducing the use of spray glue and optimizing the resin infusion process also shortens the production cycle and further improves production efficiency.
[0021] (5) During the manufacturing process of the blade, the thickness of the structural adhesive at the mold joint has an important impact on the structural integrity and durability of the blade. Too thick structural adhesive not only increases the weight, but may also lead to incomplete curing, affecting the performance of the blade. The utility model achieves precise control of the thickness of the structural adhesive at the mold joint of the trailing edge by precisely controlling the laying of the cloth layer and PVC, avoiding the over-thickness phenomenon and improving the structural integrity and durability of the blade.
[0022] (6) Wind turbine blades may face different performance requirements in different application scenarios, which requires the blade material to have a certain degree of adaptability. The utility model allows different mold materials, such as PVC or PET, to be selected according to the specific application requirements of the blade to meet different rigidity, strength and durability requirements. This material adaptability enables the blade structure of the utility model to be widely used in different types of wind turbines, improving the market adaptability and competitiveness of the product. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 A schematic diagram of the trailing edge structure of an existing design;
[0024] Figure 2 It is a schematic diagram of a wind turbine blade structure containing double-sided molded PVC according to the utility model.
[0025] Reference numerals:
[0026] 1. Pressure side ply, 2. Suction side ply, 3. Structural adhesive, 4. Membrane PVC, 5. Mould, 6. Pressure side PVC, 7. Suction side PVC. DETAILED DESCRIPTION
[0027] In order to make the purpose, technical solution and advantages of the implementation of the utility model clearer, the technical solution in the embodiment of the utility model will be described in more detail below in conjunction with the drawings in the embodiment of the utility model. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the utility model, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the utility model, and should not be understood as limitations on the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. The structure and technical solution of the utility model are further described in detail below in conjunction with the drawings, and an embodiment of the utility model is given.
[0028] The utility model proposes a wind turbine blade structure containing double-sided molded PVC, which is produced by processing the molded PVC on the pressure side and the suction side separately, and then placing them on the shell for layering. The specific structure is as follows:
[0029] The shape of the molded PVC on the pressure side and the suction side is made according to the shape of the two sides, including the PVC on the two sides and the 4-layer bidirectional cloth wrapped around the PVC. The chord-wise end position of the wrapped cloth is longer than the PVC. The purpose is to fix the molded PVC during injection. During the resin injection process, the PVC and cloth layers may be displaced due to the fluidity of the resin. By making the chord-wise end position of the bidirectional cloth longer than the PVC, the friction can be increased, the displacement can be reduced, and the stability of the PVC during the resin injection process can be ensured.
[0030] After laying the inner skin of the pressure surface and the suction surface, first use 4 layers of bidirectional cloth to lay on the suction surface and the pressure surface respectively. The cloth layer is spread to the starting position, starting from the PVC starting position and retreating 100mm layer by layer towards the blade root. The starting position of the fourth cloth layer is 300mm away from the PVC starting position. The ending position is reduced by 100mm layer by layer from the PVC ending position to the blade tip, and the fourth layer is 300mm away from the PVC ending position. The cloth layer is staggered 5mm layer by layer towards the trailing edge in the chord direction, and the center position of the cloth layer is flush with the mold line. The cloth layer is staggered 5mm layer by layer in the chord direction (i.e. the length direction of the blade), so that there is a certain overlap between the cloth layers, which enhances the bonding between the layers and the overall structural stability. The center of the overall cloth layer is flush with the mold line, ensuring the symmetry and accuracy of the layer, so that when the resin is injected, the resin flow can be more effectively controlled, the generation of voids and bubbles can be reduced, and the mechanical properties and durability of the blade can be improved.
[0031] Then place the molded PVC on the two sides respectively, and lay the PVC to the corners of the suction side and the pressure side respectively. Compact the fabric layer at the corners, without hanging or wrinkles. Chamfer the bevel side of the bevel at the starting position of the PVC in the thickness direction at 1:1. Do not chamfer in the extension direction. Finally, fold the outer side of the edge line of the fabric layer on the two sides to the PVC surface.
[0032] In the manufacturing process of wind turbine blades, the placement of molded PVC is a key step to ensure structural integrity and improve production quality. Specifically, the molded PVC is laid to the corners of the suction and pressure sides. This area is where the blade is subjected to the greatest stress when rotating, so it needs special reinforcement. By compacting the cloth layer at the corners and ensuring that there are no overhangs and wrinkles, bubbles and voids can be avoided during the subsequent resin infusion and curing process. These defects may affect the durability and strength of the blade.
[0033] The 1:1 chamfering of the bevel side of the PVC starting position is to provide a smooth transition area to reduce stress concentration, and also to facilitate the flow and penetration of the resin in this area, ensuring that the resin can fully infiltrate the fiber and improve the bonding effect. The span direction is not chamfered because no additional structural transition is required in this direction. Keeping the original shape can avoid unnecessary material waste and ensure the integrity and continuity of the fabric layer in the span direction.
[0034] Finally, the outer side of the edge line of the two sides of the cloth layer is folded to the PVC surface. This step is to further enhance the bonding between the cloth layer and the PVC to form a more solid composite structure. After the resin is cured, the folded cloth layer will form a whole with the PVC, which can improve the reliability of the blade in operation, reduce maintenance costs, and extend the service life of the blade.
[0035] Finally, the subsequent auxiliary materials are laid, and the resin is poured and cured. After the shell resin is cured, a wind turbine blade containing double-sided molded PVC is obtained. At this time, the blade contains double-sided molded PVC, and the blade is enhanced on both the suction side and the pressure side, improving its performance and fatigue resistance under complex wind conditions. The design of double-sided molded PVC helps to reduce aerodynamic noise during blade operation and improve energy conversion efficiency. It also makes the blade stronger and able to withstand long-term operation and various environmental conditions.
[0036] Preferably, one side of the outer edge of the multi-layer bidirectional cloth is folded onto the mold-matching PVC surface and fixed by heat pressing or adhesive.
[0037] Preferably, the molded PVC can be replaced with PET material according to the stiffness requirements.
[0038] The utility model has the following advantages compared with the prior art:
[0039] (1) In the traditional wind turbine blade manufacturing process, the fixation of the cloth layer is a challenge, especially in the manufacture of large blades. The cloth layer is easily displaced during the resin injection process, resulting in uneven structure. The utility model sets a molded PVC on the pressure surface and the suction surface, and uses the rigidity and shape of the PVC to pre-fix the cloth layer, effectively preventing the cloth layer from sliding and not following the shape. This fixing method reduces the reliance on additional spraying, thereby reducing the risk of reduced interlayer performance.
[0040] (2) In the laying of the vertical edge fabric layer of a large blade, in order to prevent the fabric layer from sliding down, the traditional process often requires the use of a large amount of spray glue for fixing. This not only increases the material cost, but also too much adhesive may affect the interlayer performance and reduce the durability of the blade. In the utility model, due to the fixing effect of the molded PVC, the amount of spray glue used is greatly reduced, thereby reducing the material cost and improving the interlayer performance.
[0041] (3) During the injection process of the blade, the uniform distribution of the resin is crucial. The resin easily accumulates at the corners of the pressure surface, resulting in the problem of overflow, which not only wastes materials but may also cause internal defects after curing. The utility model effectively guides the resin flow by precisely controlling the position and shape of the molded PVC, prevents the resin from overflowing at the corners, and ensures the uniform distribution of the resin throughout the blade structure.
[0042] (4) The production efficiency of wind turbine blades directly affects the manufacturing cost and market competitiveness. The utility model reduces the complexity and uncertainty in production by simplifying the cloth layer laying and fixing steps, thereby significantly improving production efficiency. In addition, reducing the use of spray glue and optimizing the resin infusion process also shortens the production cycle and further improves production efficiency.
[0043] (5) During the manufacturing process of the blade, the thickness of the structural adhesive at the mold joint has an important impact on the structural integrity and durability of the blade. Too thick structural adhesive not only increases the weight, but may also lead to incomplete curing, affecting the performance of the blade. The utility model achieves precise control of the thickness of the structural adhesive at the mold joint of the trailing edge by precisely controlling the laying of the cloth layer and PVC, avoiding the over-thickness phenomenon and improving the structural integrity and durability of the blade.
[0044] (6) Wind turbine blades may face different performance requirements in different application scenarios, which requires the blade material to have a certain degree of adaptability. The utility model allows different mold materials, such as PVC or PET, to be selected according to the specific application requirements of the blade to meet different rigidity, strength and durability requirements. This material adaptability enables the blade structure of the utility model to be widely used in different types of wind turbines, improving the market adaptability and competitiveness of the product.
[0045] Through the above embodiments, the purpose of the utility model is fully and effectively achieved. Those skilled in the art can understand that the utility model includes but is not limited to the contents described in the drawings and the above specific embodiments. Although the utility model has been described with respect to the most practical and preferred embodiments currently considered, it should be understood that the utility model is not limited to the disclosed embodiments, and any modification that does not deviate from the functional and structural principles of the utility model will be included in the scope of the claims.
Claims
1. A wind turbine blade structure containing double-sided molded PVC, characterized in that: include: Inner skin, pressure side molded PVC, suction side molded PVC, and multi-layer bidirectional fabrics respectively wrapping the pressure side molded PVC and the suction side molded PVC; Among them, the chord-wise end position of the multi-layer bidirectional fabric is longer than that of the mold-closed PVC; The multi-layer bidirectional fabric has 4 layers, and the multi-layer bidirectional fabric is laid on the suction side and the pressure side respectively; The starting position of the cloth layer is 100mm away from the starting position of the PVC layer to the blade root, and the starting position of the fourth layer is 300mm away from the starting position of the PVC. The ending position is 100mm away from the ending position of the PVC layer to the blade tip, and the fourth layer is 300mm away from the ending position of the PVC. The fabric layers are staggered 5mm in the chord direction toward the trailing edge, and the overall center position of the fabric layers is flush with the parting line.
2. A wind turbine blade structure containing double-sided molded PVC according to claim 1, characterized in that: The inner skin is made of fiber material, including glass fiber or carbon fiber.
3. A wind turbine blade structure containing double-sided molded PVC according to claim 1, characterized in that: The bevel side of the PVC starting position bevel is chamfered 1:1 in the thickness direction, but not in the span direction.
4. A wind turbine blade structure containing double-sided molded PVC according to claim 1, characterized in that: One side of the outer edge of the multi-layer bidirectional cloth is folded to the mold-matching PVC surface and fixed by heat pressing or adhesive.
5. A wind turbine blade structure containing double-sided molded PVC according to claim 1, characterized in that: The molded PVC is replaced with PET material according to the stiffness requirements of the wind turbine blades.