Segmented wind turbine blade and wind turbine comprising the same

Abstract

The utility model provides a kind of sectional wind turbine blade and wind turbine comprising it, sectional wind turbine blade includes: blade root section is made of high modulus carbon fiber or epoxy resin, the mass of blade root section accounts for 30%-35% of the mass of sectional wind turbine blade;Middle section is made of glass fiber or vinyl ester resin, the mass of middle section accounts for 45%-50% of the mass of sectional wind turbine blade;Blade tip section is made of light carbon fiber or polyurethane resin, the mass of blade tip section accounts for 20%-25% of the mass of sectional wind turbine blade;Blade root section, middle section and blade tip section are sequentially connected, and the connecting interface between two is provided with gradient transition layer, and two blade areas are connected as a whole by gradient transition layer.The utility model realizes the comprehensive optimization of blade performance, cost, transportation and maintenance by the design of different material segmentation, applicable to 10MW or more offshore wind turbine, with significant engineering application value.

Description

Technical Field

[0001] This utility model relates to the field of wind power generation technology, and in particular to a segmented wind turbine blade and a wind turbine including the same. Background Technology

[0002] In the field of wind power technology, wind turbine blades are the core component. As wind power develops towards higher power (e.g., 20MW+) and larger rotors (e.g., diameter exceeding 260 meters), the length of blades can now exceed 150 meters. Correspondingly, traditional integral blades face challenges due to their excessive size, including transportation (restrictions on oversized vehicles / bridges), hoisting (risks associated with high-altitude operations), and maintenance (requiring complete replacement for partial damage).

[0003] Therefore, existing technologies have proposed segmented blade designs, but the existing structures still have many shortcomings:

[0004] 1. Material uniformity leads to performance imbalance: Using the same material for each section (e.g., all glass fiber or all carbon fiber), the blade root section needs high stiffness but is too heavy, while the blade tip section needs to be lightweight but lacks strength. Overall cost and performance are not optimally matched.

[0005] 2. Poor reliability of interface bonding between heterogeneous materials: If different materials (e.g., carbon fiber and glass fiber) are simply spliced ​​together, due to the difference in coefficient of thermal expansion (CTE) and elastic modulus, interface stress concentration is likely to occur under long-term load, leading to debonding or fatigue cracking.

[0006] 3. Insufficient aerodynamic-material synergy: The blade profile modification of different material sections did not take into account the stiffness differences of the materials, which may cause local airflow separation and reduce wind energy capture efficiency.

[0007] Fourth, the maintenance is not targeted enough: the segmented design does not take into account the material characteristics of the material to design a quick replacement strategy. When replacing a damaged segment, the whole segment needs to be disassembled, which is time-consuming and labor-intensive.

[0008] In view of this, the inventors of this application have designed a segmented wind turbine blade and a wind turbine including the blade, in order to overcome the above-mentioned technical problems. Utility Model Content

[0009] The technical problem to be solved by this utility model is to overcome the defects of the existing segmented blade material being monotonous, having poor reliability, and requiring time and effort to maintain, and to provide a segmented wind turbine blade and a wind turbine including the same.

[0010] The present invention solves the above-mentioned technical problems through the following technical solution:

[0011] A segmented wind turbine blade, characterized in that the segmented wind turbine blade comprises:

[0012] The blade root section, made of high-modulus carbon fiber or epoxy resin, accounts for 30%-35% of the mass of the segmented wind turbine blade.

[0013] The intermediate section, made of glass fiber or vinyl ester resin, accounts for 45%-50% of the mass of the segmented wind turbine blade.

[0014] The blade tip section is made of lightweight carbon fiber or polyurethane resin, and the mass of the blade tip section accounts for 20%-25% of the mass of the segmented wind turbine blade.

[0015] The leaf root segment, the middle segment, and the leaf tip segment are connected in sequence, and a gradient transition layer is provided at the connection interface between each pair, so that the two leaf regions are connected into one unit through the gradient transition layer.

[0016] According to one embodiment of the present invention, the gradient transition layer is a hybrid carbon fiber layer, which is made of carbon fiber with a volume fraction gradually decreasing from 70% to 30%.

[0017] According to one embodiment of the present invention, the twist angle of the leaf root segment gradually decreases from 35° at the leaf root to 20°, and the twist angle of the leaf tip segment gradually decreases from 5° to -8°.

[0018] According to one embodiment of the present invention, the chord length of the leaf root segment gradually increases from 1.5 meters to 4.0 meters, and the chord length of the leaf tip segment gradually decreases from 4.5 meters to 1.2 meters.

[0019] According to one embodiment of the present invention, the connection interface between the leaf root segment, the middle segment and the leaf tip segment is connected by a connection structure and glued connection.

[0020] According to one embodiment of the present invention, a tenon groove is provided at one end of the connection interface between the leaf root segment, the middle segment and the leaf tip segment, and a positioning boss is provided at the other end. The positioning boss is inserted into the tenon groove, so that the leaf root segment, the middle segment and the leaf tip segment are fixedly connected to each other.

[0021] According to one embodiment of the present invention, the gap between the connection interface between the leaf root segment, the middle segment and the leaf tip segment is filled with epoxy adhesive to form an adhesive layer, the thickness of which is 0.5 mm to 1.0 mm.

[0022] According to one embodiment of the present invention, an annular stress relief groove is provided at the connection interface between the leaf root segment, the middle segment and the leaf tip segment.

[0023] According to one embodiment of the present invention, the stress relief groove has a width of 50 mm and a depth of 20 mm.

[0024] This utility model also provides a wind turbine, characterized in that the wind turbine includes segmented wind turbine blades as described above.

[0025] The positive and progressive effects of this utility model are as follows:

[0026] This utility model relates to a segmented wind turbine blade and a wind turbine including the blade. Through the segmented design using different materials, it achieves comprehensive optimization of blade performance, cost, transportation and maintenance. It is applicable to offshore wind turbines of 10MW and above and has significant engineering application value. Attached Figure Description

[0027] The above and other features, properties and advantages of this utility model will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always denote the same features, wherein:

[0028] Figure 1 This is a schematic diagram of the segmented wind turbine blade of this utility model.

[0029] Figure 2 This is a schematic diagram of the gradient transition layer in the segmented wind turbine blade of this utility model.

[0030] Figure 3 This is a schematic diagram of the connection between two adjacent parts in the segmented wind turbine blade of this utility model. Detailed Implementation

[0031] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0032] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Preferred embodiments of the present invention will now be described in detail, examples of which are shown in the drawings. Wherever possible, the same reference numerals will be used in all the drawings to denote the same or similar parts.

[0033] Furthermore, although the terminology used in this invention is selected from commonly known and used terms, some terms mentioned in this specification may have been selected by the applicant in his or her judgment, and their detailed meanings are explained in the relevant sections of the description herein.

[0034] Furthermore, it is required that this utility model be understood not only through the actual terminology used, but also through the meaning implied by each term.

[0035] like Figures 1 to 3 As shown, this utility model discloses a segmented wind turbine blade. Based on the blade's spanwise stress characteristics (e.g., bending moment, torque, centrifugal force) and aerodynamic requirements, the blade is divided along its spanwise into a root section 10, a middle section 20, and a tip section 30. For example, the blade can be divided into three equal parts, including the root section 10, the middle section 20, and the tip section 30. The specific segment positions of the segmented wind turbine blade need to be adjusted in conjunction with the stress trough area (e.g., bending moment gradient ≤ 10% / meter). Each segment (e.g., root section, middle section, or tip section) is adjusted, and the length of a single segment is controlled between 40 meters and 60 meters.

[0036] The blade root section 10 is made of high-modulus carbon fiber (e.g., T1100 grade) or epoxy resin (e.g., modulus 35 GPa), with an elastic modulus ≥80 GPa and a strength ≥600 MPa. The blade root section 10 accounts for 30%-35% of the mass of the segmented wind turbine blade. The blade root section 10 can withstand high bending moments or torques and has high stiffness.

[0037] The intermediate section 20 is made of glass fiber (e.g., E-CR grade) or vinyl ester resin (e.g., modulus 30 GPa), with an elastic modulus of 50-70 GPa and a strength of 300-400 MPa. The intermediate section 20 accounts for 45%-50% of the mass of the segmented wind turbine blade. The intermediate section 20 withstands moderate loads, balancing cost and weight.

[0038] The leaf tip section 30 uses lightweight carbon fiber (e.g., T700 grade) or polyurethane resin (density 1.1 g / cm³). 3 ) and foam core material (density 50kg / m 3 It is made of [material name missing]. The blade tip section 30 accounts for 20%-25% of the mass of the segmented wind turbine blade. The blade tip section 30 has the characteristics of being lightweight, having low inertia, and being fatigue-resistant.

[0039] For the connection interfaces of leaf segments made of different materials (such as leaf root segment and middle segment, middle segment and leaf tip segment, etc.), a "gradient transition + multiple constraints" structure is adopted. Specifically, leaf root segment 10, middle segment 20 and leaf tip segment 30 are connected in sequence, and a gradient transition layer 40 is set at the connection interface between each pair, so that the two parts of the leaf region are connected into one by the gradient transition layer 40.

[0040] Preferably, the gradient transition layer 40 is a hybrid carbon fiber layer, which is made of carbon fiber with a volume fraction gradually decreasing from 70% to 30%. For example, a material transition zone of 100-200mm width is prefabricated on both sides of the connection interface, such as the interface between the leaf root section (carbon fiber) and the middle section (glass fiber), using a hybrid fiber layer with a carbon fiber volume fraction gradually decreasing from 70% to 30% to reduce the abrupt change in CTE and elastic modulus (CTE difference from 25×10⁻⁻⁴).6 / ℃ decreased to 5×10⁻ 6 / ℃).

[0041] More preferably, the connection interface between the blade root segment 10, the intermediate segment 20, and the blade tip segment 30 is connected by a connection structure (mechanical connection) and adhesive bonding, i.e., a composite connection structure. For example, the connection structure can be configured as follows: a mortise and tenon groove 41 (preferably 150mm deep) is provided at one end of the connection interface between the blade root segment 10, the intermediate segment 20, and the blade tip segment 30, and a positioning boss (preferably with a tolerance ≤0.3mm) is provided at the other end. The positioning boss is inserted into the mortise and tenon groove 41, thereby fixing the blade root segment 10, the intermediate segment 20, and the blade tip segment 30 together. To further strengthen the connection between the blade root segment 10, the intermediate segment 20, and the blade tip segment 30, a connector can be used to further fix the mortise and tenon groove 41 and the positioning boss (not shown in the figure). Here, the connector can be made of high-strength bolts (e.g., titanium alloy material, with a preload of 800kN) to provide sufficient rigidity and strengthen the connection interface.

[0042] Meanwhile, the adhesive bonding can be achieved by filling the gaps at the connection interfaces between the leaf root segment 10, the middle segment 20, and the leaf tip segment 30 with a modified epoxy adhesive (temperature resistance from -50℃ to 120℃, shear strength ≥30MPa) to form an adhesive layer. Here, the thickness of the adhesive layer is preferably 0.5mm to 1.0mm. This adhesive bonding, combined with the connection structure, creates a double constraint.

[0043] Furthermore, an annular stress relief groove 50 is provided at the interface between the blade root section 10, the middle section 20, and the blade tip section 30. For example, the width of the stress relief groove 50 is preferably 50 mm, and the depth is preferably 20 mm. The stress relief groove 50 can reduce stress concentration at the interface edge, for example, by 40% of the maximum stress.

[0044] More preferably, the segmented wind turbine blades have undergone aerodynamic-material co-optimization:

[0045] I. Blade Profile Modification and Matching: Each blade segment is modified based on the same baseline airfoil, with the twist angle and chord length gradient adjusted according to material stiffness. For example, the twist angle of blade root segment 10 (high-stiffness carbon fiber) gradually decreases from 35° at the blade root to 20°, a decrease of 0.5° per meter. The chord length of blade root segment 10 gradually increases from 1.5 meters to 4.0 meters, an increase of 0.08 meters per meter. The twist angle of blade tip segment 30 (low-stiffness lightweight carbon fiber) gradually decreases from 5° to -8°, a decrease of 0.4° per meter. The chord length of blade tip segment 30 gradually decreases from 4.5 meters to 1.2 meters, a decrease of 0.07 meters per meter. This structural design effectively ensures a smooth airflow transition at the interface, such as a velocity gradient ≤5% / meter, thereby avoiding separation.

[0046] II. Dynamic Stall Suppression: A flexible carbon fiber blade, preferably 1.5 mm thick and 500 mm long, is installed at the leading edge of the blade tip section 30. Its lightweight properties suppress airflow separation caused by segmentation, improving stall margin. Experiments show a stall angle of attack delay of 3°-5°.

[0047] As described above, the segmented wind turbine blade of this utility model adopts a segmented manufacturing process: the root section 10 is molded using prepreg, with a fiber volume content ≥65%, and has reserved mechanical connection holes (tolerance ±0.1mm) and a bonding surface (roughness Ra3.2-6.3μm). The middle section 20 is vacuum-injected, with a resin impregnation time ≤30 minutes, and the core material is balsa wood (density 150kg / m³). The tip section 30 is pultruded-winding composite molded (lightweight carbon fiber unidirectional tape + polyurethane resin), with integrated foam core material for weight reduction.

[0048] The segmented wind turbine blades described in this invention enable rapid maintenance: the blade tip section 30 is designed as an independent module (e.g., weighing ≤6 tons), equipped with an electromagnetic adsorption lifting tool (which can slide along the blade guide rail), allowing for disassembly and replacement within 3-4 hours. A pre-coated anti-corrosion coating (e.g., polyurea coating, 300μm thick) is applied to the interface area to reduce environmental erosion.

[0049] This utility model also discloses a wind turbine, which includes the segmented wind turbine blades as described above.

[0050] Based on the above structural description, the design process of the segmented wind turbine blade of this utility model will be further explained, for example, the segmented and material-divided blade of a 10MW offshore wind turbine.

[0051] I. Segmentation and Material Parameters

[0052] The blade is 120 meters long and divided into 3 sections:

[0053] Leaf root section (0-40 meters): Made of T1100 carbon fiber / epoxy resin, with a fiber volume content of 68%, an elastic modulus of 85 GPa, and a weight percentage of 32%.

[0054] Middle section (40-80 meters): Made of E-CR glass fiber / vinyl ester resin, with a fiber volume content of 55%, an elastic modulus of 60 GPa, and a weight percentage of 48%.

[0055] Blade tip section (80-120 meters): T700 carbon fiber / polyurethane resin + polyurethane foam core material (density 50kg / m³), accounting for 20% of the weight.

[0056] II. Interface Design

[0057] Gradient transition layer: A 150mm wide hybrid fiber layer (carbon fiber volume fraction gradually changes from 70% to 30%) is prefabricated at the blade root and intermediate section interfaces, with a CTE difference of 25×10⁻ 6 / ℃ decreased to 4×10⁻ 6 / ℃.

[0058] Composite connection: Six M42 titanium alloy bolts (preload 900kN) are set on each side interface, combined with modified epoxy adhesive (shear strength 32MPa), with an interface adhesive layer thickness of 0.8mm.

[0059] Stress relief groove: An annular groove (50mm wide and 20mm deep) is opened on the outside, reducing the maximum stress at the interface from 800MPa to 480MPa (below the allowable value of 600MPa).

[0060] III. Performance Verification

[0061] Aerodynamic efficiency: In wind tunnel testing (incoming flow velocity 11 m / s), the blade of this application has a Cp of 0.52, which is 1% higher than that of traditional segmented blades (Cp = 0.515).

[0062] Structural strength: The interface was subjected to 10 tensile-compression cycles (load amplitude ±500kN) using an MTS testing machine, and there was no debonding or loosening of bolts.

[0063] Maintenance test: Simulating a lightning strike damage scenario to the blade tip section, the disassembly and installation of the new section were completed within 4 hours using electromagnetic lifting equipment, meeting the needs of rapid operation and maintenance at sea.

[0064] In summary, the segmented wind turbine blade and the wind turbine including the present invention have the following advantages:

[0065] I. Improved Material Efficiency: By matching high-performance / low-cost materials in different regions, the overall material cost is reduced by 15%-20% (e.g., carbon fiber usage is reduced by 25%, and the proportion of glass fiber is optimized).

[0066] II. Convenient transportation and installation: Single section length ≤ 60 meters, weight ≤ 15 tons, compatible with conventional 40-meter flatbed trucks and 800-ton cranes, reducing transportation costs by 35%.

[0067] III. High structural reliability: The gradient transition layer + composite connection structure ensures an interface fatigue life of ≥20 years (verified by accelerated fatigue testing). 7 No failure after multiple cycles), interfacial shear strength ≥25MPa (20% exceeding IEC standard).

[0068] IV. Excellent aerodynamic performance: The blade profile modification and material stiffness are designed in a coordinated manner, and the measured wind energy utilization coefficient (Cp) reaches 0.52, which is 1% higher than that of traditional segmented blades (0.515).

[0069] V. Reduced maintenance costs: The independent replacement time for the blade tip section is ≤4 hours (compared to 72 hours for traditional segmented blades), reducing maintenance costs by 60%.

[0070] For those skilled in the art, the above disclosure of utility models is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0071] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0072] Similarly, it should be noted that, in order to simplify the description of the embodiments disclosed in this application and thus aid in the understanding of one or more embodiments of the utility model, the foregoing description of the embodiments of this application sometimes combines multiple features into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the object of this application requires more features than those mentioned in the claims. In fact, the embodiments have fewer features than all the features of the single embodiments disclosed above. Some embodiments use numbers describing the number of components or attributes; it should be understood that such numbers used in the description of embodiments are modified in some examples by the modifiers "approximately," "about," or "generally."

[0073] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A segmented wind turbine blade, characterized in that, The segmented wind turbine blades include: The blade root section, made of high-modulus carbon fiber or epoxy resin, accounts for 30%-35% of the mass of the segmented wind turbine blade. The intermediate section, made of glass fiber or vinyl ester resin, accounts for 45%-50% of the mass of the segmented wind turbine blade. The blade tip section is made of lightweight carbon fiber or polyurethane resin, and the mass of the blade tip section accounts for 20%-25% of the mass of the segmented wind turbine blade. The leaf root segment, the middle segment, and the leaf tip segment are connected in sequence, and a gradient transition layer is provided at the connection interface between each pair, so that the two leaf regions are connected into one unit through the gradient transition layer.

2. The segmented wind turbine blade as described in claim 1, characterized in that, The twist angle of the leaf root segment gradually decreases from 35° at the leaf root to 20°, and the twist angle of the leaf tip segment gradually decreases from 5° to -8°.

3. The segmented wind turbine blade as described in claim 1, characterized in that, The chord length of the leaf root segment gradually increases from 1.5 meters to 4.0 meters, while the chord length of the leaf tip segment gradually decreases from 4.5 meters to 1.2 meters.

4. The segmented wind turbine blade as described in claim 1, characterized in that, The connection interfaces between the leaf root segment, the middle segment, and the leaf tip segment are connected by a connection structure and adhesive bonding.

5. The segmented wind turbine blade as described in claim 4, characterized in that, One end of the connection interface between the leaf root segment, the middle segment, and the leaf tip segment is provided with a mortise and tenon groove, and the other end is provided with a positioning boss. The positioning boss is inserted into the mortise and tenon groove, so that the leaf root segment, the middle segment, and the leaf tip segment are fixedly connected to each other.

6. The segmented wind turbine blade as described in claim 4, characterized in that, The gaps at the connection interfaces between the leaf root segment, the middle segment, and the leaf tip segment are filled with epoxy adhesive to form an adhesive layer with a thickness of 0.5 mm to 1.0 mm.

7. The segmented wind turbine blade as described in claim 4, characterized in that, An annular stress relief groove is provided at the connection interface between the leaf root segment, the middle segment, and the leaf tip segment.

8. The segmented wind turbine blade as described in claim 7, characterized in that, The stress relief groove has a width of 50mm and a depth of 20mm.

9. A wind turbine generator, characterized in that, The wind turbine includes segmented wind turbine blades as described in any one of claims 1-8.

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