A wind turbine blade pultruded spar structure and a wind turbine blade

Abstract

The utility model discloses a kind of wind power blade pultrusion girder structure and wind power blade, including the multiple sub girder structures of being arranged side by side along the width direction of main girder structure, the left and right side surface of each sub girder structure is paved with first flow guide fabric for resin infusion flow guide, the spacing inside between two adjacent sub girder structures is provided with reinforcing body structure for improving pultrusion plate interlayer combination performance and preventing pultrusion plate crack along the width direction expansion, the left and right side surface of the reinforcing body structure is contacted with adjacent first flow guide fabric, each sub girder structure includes the multiple pultrusion plates of being sequentially stacked from top to bottom, second flow guide fabric for resin infusion flow guide is paved between two adjacent pultrusion plates, the left and right sides of the second flow guide fabric are contacted with first flow guide fabric.The utility model increases various types of reinforcing body structure in the middle of each longitudinal column sub girder structure of main girder width direction, effectively increase the structural reliability of blade main 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 pultruded main beam structure for wind turbine blades and wind turbine blades. Background Technology

[0002] With the trend towards larger wind turbine blades, the loads borne by the blades are constantly increasing. Currently, large onshore and offshore wind turbine blades widely use fiberglass pultruded plates and carbon fiber pultruded plates to achieve higher blade stiffness, improve mechanical strength and load-bearing capacity, while meeting lightweight requirements, thus contributing to increased power generation during unit operation. However, during blade operation, the main beam is subjected not only to axial loads but also to loads in the flapping direction. Under the influence of significant blade flapping vibration deformation, the main beam experiences disturbances in the thickness direction. When the beam structure is subjected to bending loads, bending moments and shear forces are generated internally. The bending moment causes beam deformation, while the shear force acts on the beam's cross-section, causing relative slippage. Between each layer of pultruded plates in the blade main beam, typically only resin and flow-guiding fabric are used as interfacial bonding materials, making it difficult to achieve high interfacial performance. The interlaminar shear strength is only 50-60 MPa, far lower than the axial strength of the pultruded plate itself in the length direction of 1200-1600 MPa or more. When subjected to disturbances in the thickness direction, high interlaminar shear forces can easily occur even with relatively small bending strains. In extreme cases, this can lead to delamination failure and cracking of the main beam, which is detrimental to the safe operation of the blade. Therefore, there is an urgent need for a main beam structure that can effectively improve the interlaminar bond strength of the main beam to enhance the reliability and safety of the blade main beam. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a pultruded main beam structure for wind turbine blades. From the perspective of analyzing the stress and risks of the main beam during actual blade operation, the main beam structure is optimized and adjusted. By adding various types of reinforcing structures in the middle of each longitudinal column of sub-beams in the width direction of the main beam, the swing stiffness of the main beam is increased, and the ability to resist deformation and interlaminar shear strength under bending load conditions is improved, thereby greatly increasing the structural reliability of the blade main beam under swing deformation.

[0004] Another objective of this invention is to provide a wind turbine blade.

[0005] The objective of this utility model can be achieved by adopting the following technical solutions:

[0006] A pultruded main beam structure for wind turbine blades includes multiple sub-beam structures arranged side-by-side along the width of the main beam structure. Each sub-beam structure has a first guiding fabric laid on its left and right sides to facilitate resin infusion and flow. Adjacent sub-beam structures maintain a spacing that is equal or unequal. Within the spacing between adjacent sub-beam structures, a reinforcement structure is provided to improve the interlayer bonding performance of the pultruded plates and prevent cracks in the pultruded plates from propagating along the width direction. The width of the reinforcement structure is adapted to the width of the spacing, and its height is consistent with the height of the sub-beam structure. The left and right sides of the reinforcement structure are in contact with the adjacent first guiding fabric. Each sub-beam structure includes multiple pultruded plates stacked sequentially from top to bottom. A second guiding fabric is laid between adjacent pultruded plates to facilitate resin infusion and flow. The left and right sides of the second guiding fabric are in contact with the first guiding fabric.

[0007] Furthermore, the reinforcing structure is one or more of the following: glass fiber pultruded plate, carbon fiber pultruded plate, uniaxial GFRP plate, biaxial GFRP plate, uniaxial CFRP plate, and biaxial CFRP plate.

[0008] Furthermore, the thickness of the reinforcing structure ranges from 0.5 mm to 8 mm.

[0009] Furthermore, the pultruded plate is one or more of carbon fiber pultruded plate, glass fiber pultruded plate, or carbon-glass hybrid pultruded plate.

[0010] Furthermore, both the first and second flow-guiding fabrics are one of the following: glass fiber plain weave fabric, glass fiber biaxial fabric, carbon glass hybrid plain weave fabric, or carbon glass hybrid biaxial fabric.

[0011] Furthermore, the pultruded plate has a width of 70mm to 120mm and a thickness of 4mm to 8mm, and its four edges are rounded with a radius of R0.5 to R2.5 mm.

[0012] Another objective of this utility model can be achieved by adopting the following technical solution:

[0013] A wind turbine blade includes the pultruded main beam structure of the wind turbine blade described above.

[0014] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0015] 1. This utility model greatly improves the interlaminar bonding performance by adding a reinforcing structure between the sub-beam structures. It can effectively prevent the crack from spreading in the width direction. When microcracks occur between conventional pultruded plates, the cracks are prone to spread along the joint, leading to interlaminar failure. This utility model, through the reinforcing structure, blocks the cracks in the middle of the carbon plate in the width direction, preventing the cracks from further extending and amplifying, thereby avoiding the occurrence of overall interlaminar cracking and improving the structural reliability of the blade main beam.

[0016] 2. In order to ensure the smooth progress of the resin vacuum infusion process, this utility model innovatively applies the flow guiding fabric to both sides of the pultruded plate in the thickness direction and contacts the reinforcement structure to achieve a good resin infusion and flow guiding effect. Attached Figure Description

[0017] Figure 1 This is a front view of the pultruded main beam structure of this utility model.

[0018] Figure 2 This is a top view of the pultruded main beam structure of this utility model. Detailed Implementation

[0019] 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.

[0020] Example 1:

[0021] like Figures 1 to 2As shown, this embodiment provides a pultruded main beam structure for wind turbine blades, including multiple sub-beam structures arranged side-by-side along the width direction of the main beam structure, i.e., multiple rows of sub-beam structures. This embodiment takes four rows as an example, namely the first sub-beam structure 5, the second sub-beam structure 6, the third sub-beam structure 7, and the fourth sub-beam structure 8. The specific number of rows can be freely adjusted according to design requirements. The left and right sides of each sub-beam structure are covered with a first guiding fabric 2 to facilitate resin infusion and flow. The spacing between each pair of adjacent sub-beam structures is maintained, and the spacing may be equal or unequal. The space between each pair of adjacent sub-beam structures is provided with a reinforcing structure 4 to improve the interlayer bonding performance of the pultruded plate and prevent the cracks in the pultruded plate from propagating along the width direction. The width of the reinforcing structure 4 is adapted to the width of the spacing. The reinforcing structure 4 is spatially perpendicular to the pultruded plate in the sub-beam structure, and its height is consistent with the height of the pultruded plate in the sub-beam structure. The left and right sides of the reinforcing structure 4 are in contact with the adjacent first guide fabric 2. Each sub-beam structure includes multiple pultruded plates 1 stacked sequentially from top to bottom. A second guide fabric 3 is laid between two adjacent pultruded plates 1 to facilitate resin infusion and flow. The left and right sides of the second guide fabric 3 are in contact with the first guide fabric 2. The first guide fabric 2 and the second guide fabric 3 achieve a good resin flow effect, ensuring that the added reinforcing structure 4 does not affect the overall vacuum infusion resin molding process of the main beam.

[0022] The reinforcing structure 4 is one or more of the following: glass fiber pultruded plate, carbon fiber pultruded plate, uniaxial GFRP plate, biaxial GFRP plate, uniaxial CFRP plate, and biaxial CFRP plate. The thickness of the reinforcing structure 4 ranges from 0.5 mm to 8 mm. For example, a 5 mm thick glass fiber pultruded plate can be added between the first sub-beam structure 5 and the second sub-beam structure 6, a 2 mm thick biaxial GFRP plate can be added between the second sub-beam structure 6 and the third sub-beam structure 7, and a 4 mm thick uniaxial GFRP plate can be added between the third sub-beam structure 7 and the fourth sub-beam structure 8. In this embodiment, a 5 mm thick carbon fiber pultruded plate is used as an example.

[0023] The pultruded sheet is one or more of carbon fiber pultruded sheets, glass fiber pultruded sheets, or carbon-glass hybrid pultruded sheets. This embodiment uses a glass fiber pultruded sheet.

[0024] Both the first and second flow-guiding fabrics are one of the following: glass fiber plain weave fabric, glass fiber biaxial fabric, carbon-glass hybrid plain weave fabric, or carbon-glass hybrid biaxial fabric. In this embodiment, glass fiber plain weave fabric is used.

[0025] All pultruded sheets have the same dimensions and cross-sectional shape. The width of the pultruded sheets is 70mm to 120mm, and the thickness is 4mm to 8mm. The edges are rounded with a radius of R0.5 to R2.5 mm. In this embodiment, the fiberglass pultruded sheet is 120mm wide, 5mm thick, and has a radius of R1.0 mm for the rounded corners.

[0026] The main beam with the reinforcement structure 4 is pre-formed by vacuum resin infusion. Thermosetting resin is used as the bonding medium for various structural materials. Through a flow-guiding auxiliary material, it is introduced into the perimeter, corner areas, and central flow-guiding fabric areas of the pultruded plate under vacuum pressure. Curing is completed at 0℃~80℃ for 6h~12h. In this embodiment, curing is 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. The final result is a fully cured and structurally complete main beam with the reinforcement structure, which improves the interlayer bonding strength of the pultruded plate and enhances the overall sway load-bearing capacity of the main beam.

[0027] Example 2:

[0028] This embodiment provides a pultruded main beam structure for wind turbine blades. The difference between this embodiment and Embodiment 1 is that the pultruded plate is a carbon fiber pultruded plate with a width of 100mm, a thickness of 5mm, and a rounded corner of R1.5mm. A 3mm thick uniaxial CFRP plate reinforcement structure is added between the first sub-beam structure and the second sub-beam structure, and between the third sub-beam structure and the fourth sub-beam structure. A 3mm thick biaxial CFRP plate reinforcement structure is added between the second sub-beam structure and the third sub-beam structure. The flow guiding fabric is a carbon glass hybrid plain weave fabric.

[0029] The main beam with the above-mentioned reinforcement structure was prefabricated by vacuum injection. Polyurethane resin was used as the connecting medium for various structural materials. A flow-guiding auxiliary material was introduced into the perimeter, corner areas, and central connecting fabric areas of the pultruded plate under vacuum pressure. Curing was completed at 80°C for 6 hours. The final product is a fully cured and structurally complete main beam with the reinforcement structure, which provides higher resistance to swing deformation and higher interlayer bonding strength and stability.

[0030] Example 3:

[0031] This embodiment provides a pultruded main beam structure for wind turbine blades. The difference between this embodiment and Embodiment 1 is that the sub-beam structure has five rows, namely the first sub-beam structure, the second sub-beam structure, the third sub-beam structure, the fourth sub-beam structure, and the fifth sub-beam structure. The pultruded plate is a carbon-glass hybrid pultruded plate, which is 80mm wide, 6mm thick, and has a rounded corner of R2.0mm. A 4mm thick uniaxial GFRP plate reinforcement structure is added between the first and second sub-beam structures and between the second and third sub-beam structures. A 4mm thick biaxial GFRP plate reinforcement structure is added between the third and fourth sub-beam structures and between the fourth and fifth sub-beam structures. The flow guiding fabric is a carbon-glass hybrid biaxial fabric.

[0032] The main beam with the above-mentioned reinforcement structure was prefabricated by vacuum injection. Cycloolefin resin was used as the bonding medium for various structural materials. A flow-guiding auxiliary material was introduced into the periphery, corner areas, and central connecting flow-guiding fabric areas of the pultruded plate under vacuum pressure. Curing was completed at 75°C for 8 hours. The final product is a fully cured and structurally complete main beam with the reinforcement structure, which provides higher resistance to swing loads and better interlayer bonding performance.

[0033] Example 4:

[0034] This embodiment provides a wind turbine blade, including the pultruded main beam structure of the wind turbine blade described above.

[0035] 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 wind turbine blade pultruded spar structure, characterized in that: The structure includes multiple sub-beam structures arranged side-by-side along the width of the main beam structure. Each sub-beam structure has a first flow-guiding fabric laid on its left and right sides to facilitate resin infusion and flow. Adjacent sub-beam structures are spaced apart, with equal or unequal spacing. Within the spacing between adjacent sub-beam structures, a reinforcement structure is provided to improve the interlayer bonding performance of the pultruded plates and prevent cracks in the pultruded plates from propagating along the width direction. The width of the reinforcement structure is adapted to the width of the spacing, and its height is consistent with the height of the sub-beam structure. The left and right sides of the reinforcement structure are in contact with the adjacent first flow-guiding fabric. Each sub-beam structure includes multiple pultruded plates stacked sequentially from top to bottom. A second flow-guiding fabric is laid between two adjacent pultruded plates to facilitate resin infusion and flow. The left and right sides of the second flow-guiding fabric are in contact with the first flow-guiding fabric.

2. A wind turbine blade pultruded spar structure according to claim 1, characterised in that: The reinforcing structure is one or more of the following: glass fiber pultruded plate, carbon fiber pultruded plate, uniaxial GFRP plate, biaxial GFRP plate, uniaxial CFRP plate, and biaxial CFRP plate.

3. A wind turbine blade pultruded spar structure according to claim 2, characterised in that: The thickness of the reinforcing structure ranges from 0.5 mm to 8 mm.

4. A wind turbine blade pultruded spar structure according to claim 1, characterised in that: The pultruded plate is one or more of carbon fiber pultruded plate, glass fiber pultruded plate, or carbon-glass hybrid pultruded plate.

5. A wind turbine blade pultruded spar structure according to claim 1, characterised in that: The first and second flow guiding fabrics are both one of the following: glass fiber plain weave fabric, glass fiber biaxial fabric, carbon glass hybrid plain weave fabric, or carbon glass hybrid biaxial fabric.

6. A wind turbine blade pultruded spar structure according to claim 1, characterised in that: The pultruded plate has a width of 70mm to 120mm and a thickness of 4mm to 8mm, and its four edges are rounded with a radius of R0.5 to R2.5 mm.

7. A wind turbine blade, characterised in that: Includes the pultruded main beam structure for wind turbine blades as described in any one of claims 1 to 6.

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