A wind turbine blade preform root structure

Abstract

The utility model discloses a kind of wind power blade prefabricated root structures, including the circumferentially spliced multiple arc pultrusion prefabricated pieces, arc pultrusion prefabricated piece is integrally formed using pultrusion process, and the splicing surface of adjacent arc pultrusion prefabricated piece is provided with mutually matched mechanical interlocking structure, embedded mechanical interlocking is realized between adjacent arc pultrusion prefabricated piece through mechanical interlocking structure, and gap for filling structural adhesive is reserved between the splicing surface of adjacent arc pultrusion prefabricated piece, and the fastening connection of adjacent arc pultrusion prefabricated piece is realized through structural adhesive, the bolt hole for installing wind power blade connecting bolt is machined in the one end of the arc pultrusion prefabricated piece at least two rows, and the inside edge at the other end is provided with chamfer structure convenient for with the shell ply of wind power blade lap joint. The utility model can effectively improve the root strength, modulus and quality stability, eliminate secondary perfusion process, improve efficiency, reduce root weight and diameter, facilitate transportation.

Description

Technical Field

[0001] This utility model relates to the technical field of wind turbine blades, and in particular to a prefabricated blade root structure for wind turbine blades. Background Technology

[0002] As wind turbine blades become larger, their weight increases, leading to greater loads at the blade roots. Traditional pre-embedded bolt blade roots suffer from problems such as unstable quality, insufficient strength, easy breakage, and difficulty in removal, affecting blade reliability and lifespan. While T-shaped perforated blade roots offer a simple process and are easy to maintain, the low fiber volume content (50%–60%) under vacuum casting results in high resin consumption, increased weight, and lower unit material strength and modulus. This necessitates more material to meet design requirements, increasing manufacturing difficulty, reducing efficiency, and raising casting risks. It also leads to increased blade and overall turbine weight and cost, as well as increased transportation difficulties.

[0003] In contrast, using pultruded preforms to manufacture blade roots is a more ideal approach. The pultrusion process can significantly increase the fiber content (up to 70%–75%), thereby improving the material's strength, modulus, and stiffness. However, existing processes for manufacturing blade roots using pultruded preforms require a secondary fiberglass cloth layup and injection process, representing a combination of pultrusion and injection. This approach fails to fully leverage the advantages of pultrusion, does not significantly improve blade root manufacturing efficiency, and instead introduces considerable manufacturing risks associated with the layup process. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a prefabricated blade root structure for wind turbine blades. By employing a one-time pultrusion molding process to produce high-fiber-content, arc-shaped pultruded prefabricated segments, and connecting these segments with a mechanical interlocking structure and structural adhesive, the potential quality risks associated with secondary injection processes are reduced. This effectively improves the strength and modulus of the material itself, fundamentally enhancing the mechanical properties of the prefabricated blade root. Simultaneously, the pultruded profiles offer stable and reliable quality, eliminating the need for vacuum injection processes and avoiding potential quality defects, while also improving the manufacturing efficiency of the blade root. Furthermore, the use of pultruded profiles reduces the weight and diameter of the blade root, facilitating transportation.

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

[0006] A prefabricated blade root structure for wind turbine blades includes multiple arc-shaped pultruded prefabricated segments sequentially spliced ​​along the circumference. The arc-shaped pultruded prefabricated segments are integrally formed using a pultrusion process. The splicing surfaces of adjacent arc-shaped pultruded prefabricated segments are provided with mutually matching mechanical interlocking structures. The adjacent arc-shaped pultruded prefabricated segments are embedded mechanically interlocked through the mechanical interlocking structures. A gap for filling structural adhesive is reserved between the splicing surfaces of adjacent arc-shaped pultruded prefabricated segments. The structural adhesive is used to achieve a tight connection between adjacent arc-shaped pultruded prefabricated segments. One end of each arc-shaped pultruded prefabricated segment is machined with at least two rows of bolt holes for installing wind turbine blade connecting bolts. The inner edge of the other end is provided with a chamfered structure to facilitate overlapping with the shell of the wind turbine blade.

[0007] Furthermore, the mechanical interlocking structure includes mutually matching protrusion structures and groove structures.

[0008] Furthermore, the cross-section of the protruding structure is an arc-shaped structure, a mushroom-shaped structure, a wavy structure, or a serrated structure, and the shape of the groove structure matches the shape of the protruding structure.

[0009] Furthermore, the arc-shaped pultruded preformed slab includes multiple layers of fiberglass fabric arranged in different directions, with the multiple layers of fiberglass fabric arranged in different directions being stacked alternately and then cured and formed by pultrusion process.

[0010] Furthermore, the circular angle of the arc-shaped pultruded preformed segment is 3° to 60°, its outer arc length is 100mm to 2000mm, and its wall thickness is 50mm to 200mm.

[0011] Furthermore, the gap is 0.5mm to 3mm.

[0012] Furthermore, the chamfering structure ranges from 1:5 to 1:100.

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

[0014] 1. The precast blade root structure of this utility model adopts an integrally formed arc-shaped pultruded precast segment through pultrusion process. Each arc-shaped pultruded precast segment is composed of fiberglass fabrics of different specifications that have been woven into shape. After being impregnated with resin, the segments are extruded and composite formed through a mold of the pultrusion equipment. The arc-shaped pultruded precast segments are connected by a mechanical interlocking structure and structural adhesive. The arc-shaped pultruded precast segments use all the fabric materials that would be used in the traditional vacuum infusion process in the thickness direction, reducing the quality risks that may be caused by the secondary infusion process.

[0015] 2. The precast blade root structure of this invention improves the strength and modulus of the material itself by introducing pultruded profiles with high fiber content, fundamentally enhancing the mechanical properties of the precast blade root. Simultaneously, the pultruded profiles offer stable and reliable quality, eliminating the need for a vacuum infusion process and avoiding potential quality defects, while also increasing the manufacturing efficiency of the blade root. Furthermore, the use of pultruded profiles reduces the weight and diameter of the blade root, facilitating transportation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the prefabricated leaf root structure of this utility model.

[0017] Figure 2 This is a schematic diagram of the structure of the arc-shaped pultruded precast segment of this utility model.

[0018] Figure 3 This is a schematic diagram of the structure of the arc-shaped pultruded prefabricated segment with two rows of bolt holes of this utility model.

[0019] Figure 4 This is a schematic diagram of the structure of the arc-shaped pultruded prefabricated segment with three rows of bolt holes of this utility model.

[0020] Figure 5 This is a schematic diagram of the mushroom-shaped protrusion structure of this utility model.

[0021] Figure 6 This is a schematic diagram of the wavy structure of the protrusion structure of this utility model.

[0022] Figure 7 This is a schematic diagram of the serrated protrusion structure of this utility model.

[0023] Figure 8 This diagram illustrates the processing of curved pultruded prefabricated segments using pultrusion equipment. Detailed Implementation

[0024] 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.

[0025] like Figures 1 to 4As shown, this embodiment provides a prefabricated blade root structure for wind turbine blades, including multiple arc-shaped pultruded prefabricated segments 1 sequentially spliced ​​along the circumference. The arc-shaped pultruded prefabricated segments are integrally formed using a pultrusion process. Matching mechanical interlocking structures 2 are provided on the splicing surfaces of adjacent arc-shaped pultruded prefabricated segments 1. The adjacent arc-shaped pultruded prefabricated segments 1 are embedded mechanically interlocked through the mechanical interlocking structures 2. Furthermore, a gap of 0.5mm to 3mm is reserved between the splicing surfaces of adjacent arc-shaped pultruded prefabricated segments 1 for filling with structural adhesive. mm, the structural adhesive is selected as an epoxy or acrylic structural adhesive that can cure quickly at room temperature. The structural adhesive is used to achieve a tight connection between adjacent arc-shaped pultruded prefabricated segments 1. One end of the arc-shaped pultruded prefabricated segment 1 is machined with at least two rows of bolt holes 101 for installing wind turbine blade connecting bolts. In order to achieve the overlapping connection between the prefabricated blade root structure and the shell of the wind turbine blade, the other end of the arc-shaped pultruded prefabricated segment 1, that is, the axial end point of the design length, needs to be ground and chamfered. The chamfer structure 102 ranges from 1:5 to 1:100.

[0026] like Figures 5 to 7 As shown, the mechanical interlocking structure 2 includes mutually matching protrusion structures 201 and groove structures 202. The cross-section of the protrusion structure 201 is an arc-shaped structure, a mushroom-shaped structure 203, a wave-shaped structure 204, or a sawtooth structure 205, and the shape of the groove structure matches the shape of the protrusion structure.

[0027] The arc-shaped pultruded precast segment 1 includes multiple layers of fiberglass fabric arranged in different directions. The multiple layers of fiberglass fabric in different directions (e.g., 0°, ±45°, 90°) are stacked alternately and then solidified by the pultrusion process, realizing true one-time pultrusion molding, reducing the quality risks that may be caused by the secondary injection process, and greatly improving the mechanical bearing capacity of the blade root at different angles.

[0028] The circular angle of the arc-shaped pultruded precast segment 1 is 3° to 60°, its outer arc length is 100mm to 2000mm, and its wall thickness is 50mm to 200mm. Due to the large wall thickness and high performance, by increasing the number of bolt holes, such as setting at least two rows of bolt holes, the connection strength and load-bearing capacity of the blade root can be effectively enhanced.

[0029] like Figure 8 As shown, the processing of curved pultruded preforms is completed using pultrusion equipment. The pultrusion equipment consists of various parts including a fabric rack 01, fabric arrangement guide 02, fabric arrangement guide 03, guide rail 04, guide rail 06, resin impregnation tank 05, pultrusion die 07, heat curing chamber 08, traction device 09, and cutting device 010. The required stitch-woven fabric for the curved pultruded preforms (e.g., 1200g / m²) is... 2 Uniaxial stitched fabric or 1200g / m 2 Uniaxial stitch-knitted fabric with 1000g / m 2The triaxial stitched fabric (arranged alternately) comes down from the fabric rack 01 according to the required layup sequence. After passing through the primary arrangement guide rail 02, the fabric is gathered into several orderly arranged fabric layers. After passing through the secondary arrangement guide rail 03, the fabric is uniformly gathered together. Then, under the action of the guide rail 04, it passes through the resin impregnation tank 05 to complete the full impregnation of pultrusion resin. Under the action of the guide rail 06, it enters the pultrusion mold 07. In the mold, the thick arc-shaped pultruded preform is heated and cured. After passing through the heating and curing box 08 at a certain time and temperature, the arc-shaped pultruded preform is fully cured and finally has high strength and modulus. After passing through the traction device 09 and the cutting device 010, it is cut to the required length.

[0030] The die temperature range for the pultrusion process is 180℃~250℃, the overall pultrusion speed range is 0.01m / min~0.2m / min, and the traction force range is 100kN~500kN. The pultrusion resin can be selected from epoxy resin, polyurethane resin, vinyl ester resin, polyester resin, or acrylic resin. The fabric material is selected based on performance requirements, including fiberglass fabric, carbon fiber fabric, or a blend of both. The fabric type can be stitch-knitted uniaxial or triaxial fabric, or a blend of both. The basis weight of a single layer is 200g / m². 2 ~1500g / m 2 .

[0031] The assembly method of the prefabricated leaf root structure in this embodiment is as follows:

[0032] Apply a layer of structural adhesive evenly to the splicing surface of each arc-shaped pultruded precast segment, so that it just fills the gap in the mechanical interlocking structure connection area.

[0033] Using manual labor or hoisting equipment, each arc-shaped pultruded prefabricated segment is connected by a mechanical interlocking structure, and the adhesive is allowed to fully cure and bond for 6 to 12 hours to form a prefabricated leaf root structure with a certain bonding strength.

[0034] The precast blade root structure is ground and chamfered at the axial end point of the design length, with the chamfer range being 1:5 to 1:100.

[0035] Drill holes at the blade root connection points of the prefabricated blade root structure. Due to the large thickness and high performance of the prefabricated blade root structure, it is advisable to set at least two rows of bolt holes in the thickness direction to enhance the connection and load-bearing capacity of the blade root, and finally complete the prefabrication of the thick wind turbine blade root.

[0036] 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 prefabricated blade root structure for wind turbine blades, characterized in that: The device comprises multiple arc-shaped pultruded prefabricated segments sequentially spliced ​​along the circumference. The arc-shaped pultruded prefabricated segments are integrally formed using a pultrusion process. The splicing surfaces of adjacent arc-shaped pultruded prefabricated segments are provided with mutually matching mechanical interlocking structures. The adjacent arc-shaped pultruded prefabricated segments are embedded mechanically interlocked through the mechanical interlocking structures. Furthermore, gaps for filling structural adhesive are reserved between the splicing surfaces of adjacent arc-shaped pultruded prefabricated segments. The structural adhesive is used to achieve a tight connection between adjacent arc-shaped pultruded prefabricated segments. One end of each arc-shaped pultruded prefabricated segment is machined with at least two rows of bolt holes for installing wind turbine blade connecting bolts, and the inner edge of the other end is provided with a chamfered structure to facilitate overlapping with the shell of the wind turbine blade.

2. The prefabricated blade root structure for wind turbine blades according to claim 1, characterized in that: The mechanical interlocking structure includes mutually matching protrusions and grooves.

3. The prefabricated blade root structure for wind turbine blades according to claim 2, characterized in that: The cross-section of the protrusion structure is an arc-shaped structure or a sawtooth structure, and the shape of the groove structure matches the shape of the protrusion structure.

4. The prefabricated blade root structure for wind turbine blades according to claim 1, characterized in that: The arc-shaped pultruded prefabricated slabs include multiple layers of fiberglass fabric arranged in different directions, with the multiple layers of fiberglass fabric arranged in different directions being stacked alternately and then solidified and formed by pultrusion process.

5. The prefabricated blade root structure for wind turbine blades according to claim 1, characterized in that: The arc-shaped pultruded precast segments have a circular angle of 3° to 60°, an outer arc length of 100mm to 2000mm, and a wall thickness of 50mm to 200mm.

6. The prefabricated blade root structure for wind turbine blades according to claim 1, characterized in that: The gap is 0.5mm to 3mm.

7. The prefabricated blade root structure for wind turbine blades according to claim 1, characterized in that: The chamfering structure ranges from 1:5 to 1:100.

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