A wind power blade leading edge UD forming process and a wind power blade leading edge UD product obtained by the same

Abstract

The present application relates to the wind power blade leading edge forming process technical field, in view of the low blade production efficiency and low quality stability of the current common blade leading edge preparation process, a kind of wind power blade leading edge UD forming process and the wind power blade leading edge UD workpiece obtained thereby are provided, comprising the following steps: S1 preparation prefabricated mould;S2 preparation UD prefabricated piece;S3 assembly blade shell mould;S4 forming treatment. Through the prefabricated mould with positioning boss preparation UD prefabricated piece, effectively avoid the slide and positioning deviation of UD fiber cloth when laying, greatly reduce the wrinkle, whitening and other defects, improve the UD layer forming precision;The design of the flanging structure in UD prefabricated piece further enhances the positioning stability of prefabricated piece. The wind power blade leading edge UD workpiece prepared by using the forming process not only has high structure form precision, but also has stable quality, high generation efficiency.

Description

Technical Field

[0001] This invention relates to the field of wind turbine blade leading edge forming technology, and more specifically, to a wind turbine blade leading edge UD forming process and the resulting wind turbine blade leading edge UD part. Background Technology

[0002] As a clean and renewable energy source, wind energy has seen continuous growth in global installed capacity. Wind turbine blades, as the core component for energy conversion in wind turbine generators, operate in complex environments, enduring long-term challenges such as wind and sand impacts, rain erosion, and alternating loads. Therefore, their structural integrity and manufacturing quality directly determine the generator's power generation efficiency, operational reliability, and service life. The leading edge of the blade is the windward surface, directly bearing the impact of airflow and foreign objects. Its structural strength, fatigue resistance, and impact resistance are key factors determining the blade's service life. The leading edge region, constantly subjected to airflow impacts, raindrop erosion, and alternating loads, is a critical and vulnerable area.

[0003] Unidirectional fiber (UD) layers, with their fibers arranged in an orderly manner along a single direction, possess extremely high tensile strength and elastic modulus. They can effectively resist stress concentration generated at the leading edge of wind turbine blades during service, making them the preferred material for current blade leading edge reinforcement structures.

[0004] Currently, the industry primarily employs a traditional process combining manual layup and molding for the fabrication of the leading edge UD layer on wind turbine blades. This process has revealed numerous technical shortcomings in actual production, making it difficult to meet the high-performance, large-scale production requirements of megawatt-class wind turbine blades. Current mainstream blade leading edge fabrication processes include on-site layup and prefabricated UD components, but both suffer from low blade production efficiency and low quality stability, as well as low leading edge forming precision and poor adhesion between the leading edge and the blade body.

[0005] With the continuous growth of wind power installed capacity and the expansion of new scenarios such as offshore wind power and low-wind-speed wind power, the market's performance requirements for blade leading edges are constantly increasing. The technical bottlenecks of traditional processes have become a key factor restricting the research and development and production of high-performance wind turbine blades. Based on the current technological situation, there is an urgent need to develop a blade leading edge UD prefabrication method with a high degree of automation, controllable forming accuracy, and stable and reliable performance. This method has significant practical significance and application value for improving the quality of wind turbine blades, extending their service life, and reducing operation and maintenance costs. Summary of the Invention

[0006] The purpose of this invention is to provide a leading edge UD forming process for wind turbine blades and the resulting leading edge UD part, aiming to solve the problems of low forming accuracy and low production efficiency in the traditional wind turbine blade leading edge UD layer forming process.

[0007] This invention is achieved through the following technical solution: A leading edge UD forming process for wind turbine blades includes the following steps: (1) Preparation of prefabricated molds: A prefabricated mold adapted to the hyperboloid structure of the leading edge of a wind turbine blade was prepared, and its cross-sectional structure is shown in the figure. Figure 1 As shown, the inner surface of the precast mold is provided with a positioning boss extending in the longitudinal direction, and a flange forming groove is reserved on one side of the precast mold. A partial structure is shown below. Figure 2 As shown, the cross-sectional profile of the positioning boss matches the layup trajectory of the UD layer at the leading edge of the wind turbine blade, which can limit the layup position of the UD fiber cloth.

[0008] (2) Preparation of UD preforms: First, a release agent is evenly applied to the inner surface of the precast mold, and a bottom layer of release fabric is laid. Then, multiple layers of UD unidirectional fiber fabric are laid along the positioning boss trajectory; specifically, a staggered laying method is adopted, with the UD unidirectional fiber fabric closer to the outer edge having a longer spanning length and a chordal width that matches the leading edge profile of the corresponding blade. During the laying process, the positioning bosses restrict the displacement of the fabric layers to prevent slippage. Next, an extension section of fabric is laid in the edge area of ​​the UD fiber fabric layer, extending into the flange forming groove of the precast mold to form a flanged precast section. Finally, a release film, a flow guide net, and an air bridge are sequentially laid on the surface of the UD fiber fabric layer and the flanged precast section, covered with a vacuum bag film and sealed, and then vacuum-injected with resin. After curing, the flow guide net and other auxiliary materials, as well as the precast mold, are removed to obtain the UD precast part with a flanged structure.

[0009] The main body of the UD prefabricated component forms an angle of 90°-120° with its flange structure.

[0010] (3) Assemble the blade shell mold: Prepare a blade pressure surface shell mold and a suction surface shell mold, and respectively open positioning slots on the front edge areas of the blade pressure surface shell mold and the suction surface shell mold to match the flange structure of the UD preform; then, hoist the UD preform to the preset position on the front edge of the blade pressure surface shell mold, so that the flange structure is embedded in the positioning slot to achieve precise positioning, and the outer surface of the UD preform is in contact with the inner cavity surface of the pressure surface shell mold.

[0011] (4) Molding process: Inside the blade pressure surface shell mold, the outer skin fiberglass cloth, main beam, core material, and inner skin fiberglass cloth are laid sequentially, so that the inner skin fiberglass cloth is in contact with the inner surface of the UD preform. A release cloth is laid in the front edge area of ​​the blade suction front, with part of the width of the release cloth located inside the mold and another part extending to the mold flange edge. Each layer of the pressure surface shell is locally vacuum-injected and cured. Then, spacers are placed on the front and rear edge mold flange edges, structural adhesive is applied, and the mold is closed. After the overall curing is completed, the mold is demolded, the front edge release cloth and spacers of the suction front edge are removed, and the flange structure reserved in the UD preform is bonded and fixed to the front edge of the suction surface shell. Finally, the edges are sealed with sealant to obtain the UD component of the wind turbine blade leading edge.

[0012] The technical solution of the present invention has at least the following advantages and beneficial effects: The wind turbine blade leading edge UD forming process proposed in this invention uses a customized prefabrication mold with positioning bosses to prepare UD preforms, effectively avoiding slippage and positioning deviation of the UD fiber cloth during on-site layering, significantly reducing defects such as wrinkles and whitening, and improving the forming accuracy of the UD layer. The design of the flange structure in the UD preform further enhances the positioning stability of the preform. The wind turbine blade leading edge UD preforms prepared using this forming process not only have high structural accuracy and stable quality, but also high production efficiency, shortening the preparation cycle of a single preform, and meeting the large-scale production needs of megawatt-level wind turbine blades, ultimately achieving high-performance, low-cost, and standardized manufacturing of wind turbine blade leading edge structures. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of the prefabricated mold in this invention. Figure 2 This is a partial structural schematic diagram of the prefabricated mold in this invention; Figure 3 This is a flowchart of the leading edge UD forming process of wind turbine blades in this invention; Figure 4 This is a physical image of the leading edge UD component of the wind turbine blade in Example 1. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, they are performed according to conventional conditions or conditions recommended by the manufacturer; where the manufacturers of the instruments, equipment, reagents, or raw materials used are not specified, they are all conventional products that can be purchased commercially.

[0015] Example 1

[0016] Step 1: Prepare the leading edge UD preform mold This embodiment uses a 120m-class EN200G blade as an example, with the following parameters: ① Total length of the prefabricated section: 25000mm, covering the easily eroded area from the blade root to the leading edge of the blade tip; ② Tangential coverage width: 150mm each for the pressure surface and suction surface, total tangential width 300mm; ③ Molding thickness: 12mm (12 layers of UD fabric, single layer weight 1200g / m²). 2 (After curing, the resin content is approximately 30%). Based on the required leading-edge UD design parameters for the project, a dedicated leading-edge UD prefabricated mold is prepared to ensure precise matching between the mold surface and the blade main mold surface, meeting the bonding requirements for subsequent integration molding. The prefabricated mold's inner cavity surface is equipped with a positioning boss extending along the spanwise direction, and a flange forming groove is reserved on one side of the prefabricated mold. The cross-sectional profile of the positioning boss matches the layup trajectory of the UD layer at the leading edge of the wind turbine blade.

[0017] Step 2: Leading edge UD prefabrication (1) Laying the UD fabric under the auxiliary material According to the process requirements, the lower auxiliary material, including the lower guide net and the release cloth, is laid in the precast mold. At the same time, the chord and axial positioning lines of the cloth layer are drawn on the surface of the auxiliary material to clarify the laying range of the UD cloth layer.

[0018] (2) Lay the leading edge UD fabric layer Lay the UD fabric layer into the positioning area of ​​the lower auxiliary material. After laying, trim the fabric layer and simultaneously confirm that the fabric layer size meets the requirements.

[0019] (3) Laying UD fabric layer and auxiliary materials Lay out the upper auxiliary materials, including the isolation membrane, the upper guide net, and the vacuum bag film, in sequence, and fix the position of the auxiliary materials strictly according to the positioning requirements; Seal the vacuum bag film, open the vacuum pump valve to draw a vacuum, and adjust the vacuum bag film to fit tightly against the mold's flange corners, flow channels, and exhaust vacuum pipe, ensuring that the bag film is not taut after vacuuming; at the same time, press the sealing strip along the edge of the mold to ensure that the vacuum bag film, sealing strip, and mold are tightly fitted to prevent air leakage; After the first layer of vacuum bag film is tightened to the vacuum pump reading ≤-81Kpa, the second layer of vacuum bag film is sealed; the two layers of bag film are connected by a guide net / breathable cotton, and the guide net / breathable cotton is laid in a Z-shape connecting the front and rear edges, extending from the root of the mold to the tip. After sealing the two layers of vacuum film, insert the spiral steel wire tube into the glue injection seat; when the vacuum gauge reading inside the first layer of vacuum film is <20mbar, close the first layer of vacuum pump and the valve of the air extraction pipeline, keep all air extraction ports open, and continue to extract air from the second layer of vacuum film and start to maintain pressure; if the vacuum change does not exceed 15mbar within 10 minutes, it indicates that the vacuum film is well sealed and you can proceed to the next step.

[0020] (4) Vacuum infusion Before injection, vent the air for 5 minutes. After venting the injection tube, open the injection valve approximately 45° until injection is complete. Inject the tubes in sequence: first open the injection port, and when the resin in the guide tube exceeds the other injection ports by 2 meters, observe that there are no air bubbles in the front section of the ohm tube before opening the corresponding injection port. Turn on the heating 0-5 minutes before the end of injection. The heating method is as follows: first heat and maintain at 55°C for 90 minutes, then heat to 75°C and maintain for 240 minutes. After pouring, when the product surface temperature is above 60℃ before the exothermic peak, remove the insulation cotton; after the exothermic peak, when the temperature is below 60℃, cover with a cotton quilt; when the surface temperature is above 65℃, cooling is required; during the insulation process, ensure the vacuum degree is ≤25mbar; when the surface temperature at the temperature measuring point reaches 50-60℃, keep it at this temperature for 3 hours to ensure the product is completely cured, then turn off the heater and vacuum system; after the product is completely cured, the hardness must be ≥55HD before the film can be peeled off, and the surface temperature must drop below 45℃ before demolding.

[0021] (5) Demolding Before removing the film from the front edge beam, test the hardness of the product at a designated location on the windward and leeward sides within a range of 0-20mm from the product edge on the air extraction side of the front edge beam using a Shore hardness tester. The hardness should be ≥55HD. Before demolding, check the surface temperature of the product, which should be <45℃. At the same time, press the product surface with your finger to confirm that there are no uncured areas in the product area before demolding.

[0022] (6) Shaping According to the width requirements of the PS / SS front edge in the front edge beam layup, the width of the precast front edge beam is confirmed by marking lines. During the shaping process, ensure that the width of the front edge beam meets the specifications. Use sandpaper to clean the rough edges of the front edge beam, being careful not to damage the front edge beam layup during sanding. Grind the corner edges of the beam's start and end points into R20 rounded corners. After cleaning the dust off the product surface, use a crane to transfer the product to the conformal fixture for storage, to be used in the shell layup process.

[0023] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A process for forming the leading edge UD of a wind turbine blade, characterized in that, Includes the following steps: S1. Prepare the prefabricated mold; The inner surface of the precast mold is provided with a positioning boss extending in the longitudinal direction, and a flange forming groove is reserved on one side of the precast mold. S2 Preparation of UD Preforms: Apply a release agent to the inner surface of the precast mold and lay a bottom layer of release cloth. Then, lay multiple layers of UD unidirectional fiber cloth along the positioning boss trajectory to form a UD fiber cloth layup. Next, lay an extension cloth segment in the edge area of ​​the UD fiber cloth layup. The extension cloth segment extends into the flange forming groove of the precast mold to form a flange prefabricated part. Lay auxiliary materials on the surface of the UD fiber cloth layup and the flange prefabricated part, cover with a vacuum bag film and seal. Vacuum infuse resin. After curing, remove the auxiliary materials and the precast mold to obtain a UD precast part with a flange structure. S3 Assembly blade housing mold: Prepare the blade pressure surface shell mold and suction surface shell mold; hoist the UD preform to the preset position at the front edge of the blade pressure surface shell mold, so that the flange structure is embedded in the positioning slot, and the outer surface of the UD preform is in contact with the inner cavity surface of the pressure surface shell mold; S4 Molding Process: Inside the blade pressure surface shell mold, the outer skin fiberglass cloth, the main beam, the core material, and the inner skin fiberglass cloth are laid in sequence. A release cloth is laid in the front edge area of ​​the blade suction face. Each layer of the pressure face shell is locally vacuum-injected and cured. Then, a pad is placed on the flange edge of the front and rear edge molds, structural adhesive is applied, and the mold is closed. After curing, the mold is demolded, and the flange structure reserved in the UD preform is bonded and fixed to the front edge of the suction face shell. The edge is sealed with sealant to obtain the UD component of the wind turbine blade front edge.

2. The wind turbine blade leading edge UD forming process according to claim 1, characterized in that, In step S1, the structural contour of the prefabricated mold is adapted to the hyperboloid structure of the leading edge of the wind turbine blade, and the cross-sectional contour of the positioning boss is matched with the UD layer layup trajectory of the leading edge of the wind turbine blade.

3. The wind turbine blade leading edge UD forming process according to claim 1, characterized in that, In step S2, when laying multiple layers of UD unidirectional fiber cloth, a staggered laying method is adopted, and the UD unidirectional fiber cloth closer to the outside has a longer span.

4. The wind turbine blade leading edge UD forming process according to claim 3, characterized in that, During installation, the chord width is matched with the leading edge profile of the blade at the corresponding position, and the displacement of the layers is restricted by positioning bosses during the layup process.

5. The wind turbine blade leading edge UD forming process according to claim 1, characterized in that, In step S2, the auxiliary materials include the isolation membrane, the guide net, and the air bridge, which are laid out in sequence.

6. The wind turbine blade leading edge UD forming process according to any one of claims 1 to 5, characterized in that, In step S2, the main body of the UD preform and the flange structure form an angle of 90°-120°.

7. The wind turbine blade leading edge UD forming process according to claim 1, characterized in that, In step S3, positioning slots adapted to the flange structure of the UD preform are respectively opened in the leading edge areas of the blade pressure surface shell mold and the suction surface shell mold.

8. The wind turbine blade leading edge UD forming process according to claim 1, characterized in that, In step S4, when laying the outer skin fiberglass cloth, main beam, core material, and inner skin fiberglass cloth in sequence, control the inner skin fiberglass cloth to adhere to the inner surface of the UD preform.

9. The wind turbine blade leading edge UD forming process according to claim 1 or 8, characterized in that, In step S4, part of the width of the release cloth is located inside the mold, and another part of the width extends to the edge of the mold flange.

10. A leading edge UD component for a wind turbine blade, characterized in that, The wind turbine blade leading edge UD forming process described in any one of claims 1 to 9 is used to prepare the blade.

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