A wind power blade windward surface carbon-glass mixed pultrusion main beam structure

Abstract

The utility model discloses a kind of wind power blade windward surface carbon glass mixed pulling and extruding girder structure, including glass fiber pultrusion plate, carbon fiber pultrusion plate, carbon fiber lightning protection fabric and carbon glass mixed flow guide fabric, the carbon fiber pultrusion plate has multiple layers, multiple layers carbon fiber pultrusion plate are sequentially laminated from bottom to top, the glass fiber pultrusion plate is laminated and is set on the top surface of the uppermost carbon fiber pultrusion plate, the outer layer of the glass fiber pultrusion plate is wrapped with carbon fiber lightning protection fabric for enhancing the overall conductivity of girder in thickness direction and forming equipotential, and carbon glass mixed flow guide fabric for flow guiding and lightning protection is laid between every two adjacent carbon fiber pultrusion plate. The utility model is analyzed from the stress condition of blade actual operation windward surface girder and the risk angle, and the blade windward surface girder structure is optimized and adjusted, effectively increase the strain threshold of blade under bending load condition, to improve the structural reliability of blade windward surface girder under waving deformation.

Description

Technical Field

[0001] This utility model relates to the technical field of wind turbine blades, and in particular to a carbon-glass composite pultruded main beam structure for the windward side of a wind turbine blade. Background Technology

[0002] With the trend towards larger wind turbine blades, the loads borne by the blades are constantly increasing. To ensure the axial stiffness of the blades, improve mechanical strength and load-bearing capacity, and meet the requirements for lightweighting, the material of the windward main beam of large onshore and offshore blades has been switched from fiberglass pultruded sheets to carbon fiber pultruded sheets. The modulus of carbon fiber pultruded sheets can generally reach over 140 GPa, far exceeding the 60-65 GPa of fiberglass pultruded sheets, resulting in a significant improvement in mechanical properties and achieving a main beam weight reduction of over 20%, which is beneficial to increasing the power generation of the unit. However, the windward main beam of the blade is often subjected to complex disturbances in various directions during actual operation, especially in the thickness direction (flaring direction). In extreme cases, this may lead to delamination failure and cracking of the windward main beam. Under bending conditions, the blade main beam simultaneously experiences compression, tension, and shear forces, generating bending moments and shear forces within it. Carbon fiber pultruded sheets (CFPS) and glass fiber pultruded sheets (GFPS) exhibit significant differences in properties. Currently, only resin infusion and flow-guiding fabrics are used as interfacial bonding materials in blade main spars, making it difficult to achieve high interfacial performance. The interlaminar shear strength is only 50–60 MPa, far lower than the 1200–1600 MPa or higher strength along the length of the pultruded sheet itself. Furthermore, CFPS have high stiffness but low toughness, with a compressive elongation at break of only about 1%. Under relatively small bending strain, they are prone to high compressive stress and interlaminar shear force, leading to carbon sheet fracture or interlaminar failure. This failure mode makes the bending strain of the carbon fiber main spars a critical weak point. Even with high stiffness, the CFPS cannot withstand large flapping loads, posing a significant risk to the safe operation of the blade. Therefore, a technical solution that can effectively improve the interlaminar properties and compressive fracture resistance of carbon fiber main spars is urgently needed to enhance the reliability and safety of blade main spars. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a carbon-glass hybrid pultruded main beam structure for the windward side of a wind turbine blade. Based on the analysis of the stress and risks of the main beam on the windward side of the blade during actual operation, the structure of the main beam on the windward side of the blade is optimized and adjusted to effectively increase the strain threshold of the blade under bending load conditions, thereby improving the structural reliability of the main beam on the windward side of the blade under flapping deformation.

[0004] The objective of this utility model can be achieved by adopting the following technical solutions:

[0005] A carbon-glass hybrid pultruded main beam structure for the windward side of a wind turbine blade includes a glass fiber pultruded plate, a carbon fiber pultruded plate, a carbon fiber lightning protection fabric, and a carbon-glass hybrid current-guiding fabric. The carbon fiber pultruded plate has multiple layers, which are stacked sequentially from bottom to top. The glass fiber pultruded plate is stacked on the top surface of the uppermost carbon fiber pultruded plate. The outer layer of the glass fiber pultruded plate is wrapped with carbon fiber lightning protection fabric to enhance the overall conductivity of the main beam in the thickness direction and form an equipotential. The carbon-glass hybrid current-guiding fabric for current guidance and lightning protection is laid between adjacent carbon fiber pultruded plates.

[0006] Furthermore, the carbon fiber lightning protection fabric is one of carbon uniaxial fabric, carbon biaxial fabric, or carbon plain weave fabric.

[0007] Furthermore, the carbon-glass hybrid flow-guiding fabric is one of carbon-glass hybrid plain weave fabric or carbon-glass hybrid biaxial fabric.

[0008] A carbon-glass hybrid pultruded main beam structure for the windward side of a wind turbine blade includes a carbon-glass hybrid pultruded plate, a carbon fiber pultruded plate, a carbon fiber lightning protection fabric, and a carbon-glass hybrid current-guiding fabric. The carbon fiber pultruded plate has multiple layers, which are stacked sequentially from bottom to top. The carbon-glass hybrid pultruded plate is stacked on the top surface of the uppermost carbon fiber pultruded plate. The outer layer of the carbon-glass hybrid pultruded plate is wrapped with carbon fiber lightning protection fabric to enhance the overall conductivity of the main beam in the thickness direction and form equipotential. The carbon-glass hybrid current-guiding fabric for current guidance and lightning protection is laid between adjacent carbon fiber pultruded plates.

[0009] Furthermore, the carbon-glass hybrid pultruded plate is a glass-clad carbon structure, which includes an internal structure and a glass fiber structure disposed on the outer layer of the internal structure. The internal structure includes at least one layer of carbon fiber.

[0010] Furthermore, the carbon-glass hybrid pultruded plate has a uniform carbon-glass hybrid structure.

[0011] Furthermore, the carbon fiber lightning protection fabric is one of carbon uniaxial fabric, carbon biaxial fabric, or carbon plain weave fabric.

[0012] Furthermore, the carbon-glass hybrid flow-guiding fabric is one of carbon-glass hybrid plain weave fabric or carbon-glass hybrid biaxial fabric.

[0013] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0014] 1. This invention improves the maximum compressive strain capacity of the main beam under bending by replacing the most critical outer layer of the conventional carbon fiber pultruded sheet in the thickness direction with a glass fiber pultruded sheet or a carbon-glass hybrid pultruded sheet. This prevents the pultruded sheet on the upper surface of the main beam from being crushed and avoids interlaminar failure of the pultruded sheet. Even under large bending deformation of the main beam, the carbon fiber pultruded sheet can still maintain its high stiffness performance.

[0015] 2. This utility model achieves good overall conductivity and lightning protection effect of the carbon-glass hybrid pultruded main beam by adding a ring of carbon fiber lightning protection fabric around the outside of the glass fiber pultruded plate or carbon-glass hybrid pultruded plate, thus realizing the overall equipotentiality and conductivity of the main beam.

[0016] 3. The carbon-glass hybrid pultruded main beam structure of this utility model effectively improves the structural stability of the main beam under large deformation through minor improvements, while retaining the high stiffness of the pultruded main beam structure, thereby improving the safety and reliability of blade operation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the carbon-glass composite pultruded main beam structure of Example 1.

[0018] Figure 2 This is a schematic diagram of the carbon-glass composite pultruded main beam structure of Example 2.

[0019] Figure 3 This is a schematic diagram of the carbon-glass hybrid pultruded plate of Example 2, which has a carbon fiber layer.

[0020] Figure 4 This is a schematic diagram of the carbon-glass hybrid pultruded plate with two carbon fiber layers in Example 2.

[0021] Figure 5 This is a schematic diagram of the structure of the carbon-glass hybrid pultruded plate of Example 2, which has three carbon fiber layers.

[0022] Figure 6 This is a schematic diagram of the carbon-glass hybrid pultruded plate of Example 2, which has a uniform carbon-glass hybrid structure. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the protection scope of this utility model.

[0024] Example 1:

[0025] like Figure 1 As shown, this embodiment provides a carbon-glass hybrid pultruded main beam structure for the windward side of a wind turbine blade, including a glass fiber pultruded plate 1, a carbon fiber pultruded plate 2, a carbon fiber lightning protection fabric 3, and a carbon-glass hybrid current-guiding fabric 4. The carbon fiber pultruded plate 2 has multiple layers, which are stacked sequentially from bottom to top. The glass fiber pultruded plate 1 is stacked on the top surface of the topmost carbon fiber pultruded plate 2. The outer layer of the glass fiber pultruded plate 1 is wrapped with carbon fiber lightning protection fabric 3 to enhance the overall conductivity of the main beam in the thickness direction and form equipotential. The carbon-glass hybrid current-guiding fabric 4 is laid between each pair of adjacent carbon fiber pultruded plates 2, ultimately achieving good current-guiding and lightning protection effects.

[0026] All pultruded sheets have the same dimensions and cross-sectional shape. The width of the pultruded sheets ranges from 70mm to 120mm, and the thickness ranges from 4mm to 8mm. The four corners of the pultruded sheet cross-section are rounded, ranging from R0.5 to R2.5. In this embodiment, the pultruded sheet is 100mm wide and 5mm thick, and the four corner rounds (R-angles) of the pultruded sheet cross-section are R1.0.

[0027] The carbon fiber lightning protection fabric is one of carbon uniaxial fabric, carbon biaxial fabric, or carbon plain weave fabric. In this embodiment, the outer perimeter of the top layer of fiberglass pultruded plate is wrapped with carbon biaxial fabric.

[0028] The carbon-glass hybrid conductive fabric is either a plain-weave carbon-glass hybrid fabric or a biaxial carbon-glass hybrid fabric. In this embodiment, a plain-weave carbon-glass hybrid conductive fabric is laid between the layers of the carbon fiber pultruded plate to achieve good conductivity and lightning protection.

[0029] The above-mentioned carbon-glass hybrid pultruded main beam structure was prefabricated by vacuum infusion. Thermosetting resin was used as the connecting medium for various structural materials. Through a flow-guiding auxiliary material, it was introduced into the perimeter, rounded corner areas, and connecting flow-guiding fabric areas of the pultruded plate, as well as the carbon fiber fabric area of ​​the top pultruded plate, under vacuum pressure. Curing was completed at 0℃~80℃ for 6h~12h. In this embodiment, curing was completed at 70℃ for 10h. The thermosetting resin can be selected from epoxy resin, polyurethane resin, polyester resin, vinyl ester resin, or cycloolefin resin. This embodiment uses epoxy resin, resulting in a fully cured and structurally complete carbon-glass hybrid pultruded main beam. When applied to the windward side of blades, it provides a better balance between structural stiffness and swing bending stability.

[0030] Example 2:

[0031] like Figure 2As shown, this embodiment provides a carbon-glass hybrid pultruded main beam structure for the windward side of a wind turbine blade, including a carbon-glass hybrid pultruded plate 5, a carbon fiber pultruded plate 2, a carbon fiber lightning protection fabric 3, and a carbon-glass hybrid current-guiding fabric 4. The carbon fiber pultruded plate 2 has multiple layers, which are stacked sequentially from bottom to top. The carbon-glass hybrid pultruded plate 5 is stacked on the top surface of the topmost carbon fiber pultruded plate 2. The outer layer of the carbon-glass hybrid pultruded plate 5 is wrapped with carbon fiber lightning protection fabric 3 to enhance the overall conductivity of the main beam in the thickness direction and form equipotential. The carbon-glass hybrid current-guiding fabric 4 is laid between each pair of adjacent carbon fiber pultruded plates 2, ultimately achieving good current-guiding and lightning protection effects.

[0032] All pultruded sheets have the same dimensions and cross-sectional shape. The width of the pultruded sheets ranges from 70mm to 120mm, and the thickness ranges from 4mm to 8mm. The four corners of the pultruded sheet cross-section are rounded, ranging from R0.5 to R2.5. In this embodiment, all pultruded sheets are 120mm wide and 5mm thick, with the four corners of the pultruded sheet cross-section rounded to R1.5.

[0033] like Figures 3 to 6 As shown, the carbon-glass hybrid pultruded plate 5 has a glass-encased carbon structure or a uniform carbon-glass hybrid structure.

[0034] When the carbon-glass hybrid pultruded plate 5 is a glass-encased carbon structure, it includes an internal structure and a glass fiber structure disposed on the outer layer of the internal structure. The internal structure includes at least one layer of carbon fiber.

[0035] The carbon fiber lightning protection fabric is one of carbon uniaxial fabric, carbon biaxial fabric, or carbon plain weave fabric. In this embodiment, the outer perimeter of the top layer of fiberglass pultruded plate is wrapped with carbon uniaxial fabric.

[0036] The carbon-glass hybrid conductive fabric is either a plain-weave carbon-glass hybrid fabric or a biaxial carbon-glass hybrid fabric. In this embodiment, a biaxial carbon-glass hybrid fabric is laid between the layers of the carbon fiber pultruded plate to achieve good conductivity and lightning protection.

[0037] The above-mentioned carbon-glass hybrid pultruded main beam structure was prefabricated by vacuum infusion. Thermosetting resin was used as the connecting medium for various structural materials. Through a flow-guiding auxiliary material, it was introduced into the perimeter, rounded corner areas, and connecting flow-guiding fabric areas of the pultruded plate, as well as the carbon fiber fabric area of ​​the top pultruded plate, under vacuum pressure. Curing was completed at 0℃~80℃ for 6h~12h. In this embodiment, curing was completed at 80℃ for 8h. The thermosetting resin can be selected from epoxy resin, polyurethane resin, polyester resin, vinyl ester resin, or cycloolefin resin. This embodiment uses vinyl ester resin, resulting in a fully cured and structurally complete carbon-glass hybrid pultruded main beam. When applied to the windward side of blades, it provides a better balance between structural stiffness and swing bending stability.

[0038] Example 3:

[0039] This embodiment provides a carbon-glass hybrid pultruded main beam structure for the windward side of a wind turbine blade. The difference between this embodiment and Embodiment 2 is that the pultruded plate has a width of 80mm, a thickness of 6mm, and four corner radii of R2.0. The outermost layer of the carbon-glass hybrid pultruded plate is wrapped with carbon biaxial fabric, and carbon-glass hybrid biaxial fabric is laid between the carbon fiber pultruded plate layers.

[0040] The above carbon-glass hybrid pultruded main beam structure was prefabricated by vacuum infusion. Cycloolefin resin was used as the connecting medium for various structural materials. Through the flow-guiding auxiliary material, it was introduced into the periphery, rounded corner area, and middle flow-guiding fabric area of ​​the pultruded plate, as well as the carbon fiber fabric area of ​​the top pultruded plate, under vacuum bag pressure. The curing was completed at 0℃~80℃ for 6h~12h. In this embodiment, the curing was completed at 75℃ for 8h. The final result is a fully cured and structurally complete carbon-glass hybrid pultruded main beam, which, when applied to the windward side of blades, can bring better balance performance in terms of structural stiffness and swing bending stability.

[0041] The above description is only a preferred embodiment of this utility model patent, but the protection scope of this utility model patent is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the scope disclosed in this utility model patent, based on the technical solution and utility model patent concept of this utility model patent, shall fall within the protection scope of this utility model patent.

Claims

1. A carbon-glass composite pultruded main beam structure for the windward side of a wind turbine blade, characterized in that: The material includes fiberglass pultruded plates, carbon fiber pultruded plates, carbon fiber lightning protection fabric, and carbon-fiber hybrid conductive fabric. The carbon fiber pultruded plates are multi-layered, and the multi-layered carbon fiber pultruded plates are stacked sequentially from bottom to top. The fiberglass pultruded plates are stacked on the top surface of the topmost carbon fiber pultruded plate. The outer layer of the fiberglass pultruded plate is wrapped with carbon fiber lightning protection fabric to enhance the overall conductivity of the main beam in the thickness direction and form equipotential. Furthermore, carbon-fiber hybrid conductive fabric for current conduction and lightning protection is laid between each pair of adjacent carbon fiber pultruded plates.

2. The carbon-glass composite pultruded main beam structure on the windward side of the wind turbine blade according to claim 1, characterized in that: The carbon fiber lightning protection fabric is one of carbon uniaxial fabric, carbon biaxial fabric, or carbon plain weave fabric.

3. The carbon-glass composite pultruded main beam structure on the windward side of the wind turbine blade according to claim 1, characterized in that: The carbon-glass hybrid flow-guiding fabric is one of carbon-glass hybrid plain weave fabric or carbon-glass hybrid biaxial fabric.

4. A carbon-glass composite pultruded main beam structure for the windward side of a wind turbine blade, characterized in that: The material includes a carbon-glass hybrid pultruded plate, a carbon fiber pultruded plate, a carbon fiber lightning protection fabric, and a carbon-glass hybrid conductive fabric. The carbon fiber pultruded plate has multiple layers, which are stacked sequentially from bottom to top. The carbon-glass hybrid pultruded plate is stacked on the top surface of the topmost carbon fiber pultruded plate. The outer layer of the carbon-glass hybrid pultruded plate is wrapped with a carbon fiber lightning protection fabric to enhance the overall conductivity of the main beam in the thickness direction and form an equipotential. Furthermore, carbon-glass hybrid conductive fabric for current conduction and lightning protection is laid between adjacent carbon fiber pultruded plates.

5. The wind turbine blade windward carbon-glass composite pultruded main beam structure according to claim 4, characterized in that: The carbon-glass hybrid pultruded plate is a glass-clad carbon structure, which includes an internal structure and a glass fiber structure disposed on the outer layer of the internal structure. The internal structure includes at least one layer of carbon fiber.

6. The wind turbine blade windward carbon-glass composite pultruded main beam structure according to claim 4, characterized in that: The carbon-glass hybrid pultruded plate has a uniform carbon-glass hybrid structure.

7. The wind turbine blade windward carbon-glass composite pultruded main beam structure according to claim 4, characterized in that: The carbon fiber lightning protection fabric is one of carbon uniaxial fabric, carbon biaxial fabric, or carbon plain weave fabric.

8. The wind turbine blade windward carbon-glass composite pultruded main beam structure according to claim 4, characterized in that: The carbon-glass hybrid flow-guiding fabric is one of carbon-glass hybrid plain weave fabric or carbon-glass hybrid biaxial fabric.

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