Blade spar and wind turbine blade

Abstract

This utility model relates to the field of wind turbine technology, and the technical problem it aims to solve is the insufficient fatigue strength. To address this problem, this utility model provides a blade main beam and a wind turbine blade. The utility model includes: an upper blade main beam comprising multiple spliced ​​upper sub-beams; the upper sub-beam includes a C-shaped connecting body and two connecting lugs; the connecting lugs are formed by bending outwards from the end of the connecting body; a lower blade main beam comprising multiple spliced ​​lower sub-beams; the upper and lower blade main beams are joined vertically, and their connecting lugs are fixedly connected; a strength-equalizing connection assembly comprising a C-shaped strength-equalizing connection part and a connecting plate; the connecting plate is connected to the opening of the strength-equalizing connection part; at the splicing position, the strength-equalizing connection assembly is inserted into the interior of the connecting body, and the top wall of the strength-equalizing connection part is fixedly connected to the top wall of the connecting body. The fatigue strength of the blade of this utility model meets the requirements.

Description

Technical Field

[0001] This utility model relates to the field of wind turbine technology, and in particular to a blade main beam and a wind turbine blade. Background Technology

[0002] Existing blades are commonly made of fiberglass, which is relatively expensive. To reduce costs, a steel frame is often used, and then a 3000mm skin is laid on top of the frame to form the blade. However, due to the blade's length and variable cross-section, and considering the feasibility of the process, the frame is often constructed by splicing multiple segments, with welding used for fixing at the joints. During operation, the blade experiences flapping vibrations due to uneven aerodynamic loads and alternating gravity. Furthermore, the tangential aerodynamic load fluctuations and centrifugal force cause oscillations. Periodic flapping leads to alternating stress in the blade material, which can easily cause fatigue cracks over time. The oscillation frequency is usually high and easily couples with the blade's rotational frequency and harmonics, resulting in high-frequency alternating stress and accelerating material fatigue. However, the thermal effects, structural changes, and defects during welding significantly alter the material's fatigue properties, with the impact on the fatigue limit being particularly critical. Fatigue cracks easily initiate at stress concentration points, causing the material's actual "effective fatigue limit" to be significantly lower than that of the base material. This typically leads to cracks around the weld, eventually resulting in fracture. Utility Model Content

[0003] Therefore, the technical problem to be solved by this utility model is to overcome the above-mentioned problems existing in the prior art.

[0004] To solve the above-mentioned technical problems, this utility model provides a blade main beam, comprising:

[0005] The upper blade main beam includes multiple spliced ​​upper sub-beams; the upper sub-beam includes a C-shaped connecting body and two connecting lugs; the connecting lugs are formed by bending outward from the end of the connecting body;

[0006] The lower blade main beam consists of multiple spliced ​​lower sub-beams; the lower sub-beams have the same structure as the upper sub-beams; the upper blade main beam and the lower blade main beam are connected vertically, and the connecting lugs of the two are fixedly connected.

[0007] The equal-strength connection component includes a C-shaped equal-strength connection part and a connecting plate; the connecting plate is connected to the opening of the equal-strength connection part.

[0008] Adjacent upper sub-beams and adjacent lower sub-beams are spliced ​​together by equal-strength connecting components; at the splicing position, the equal-strength connecting components are inserted into the interior of the connecting body, and the top wall of the equal-strength connecting part is connected and fixed to the top wall of the connecting body.

[0009] In one embodiment of this utility model, a reinforcing member is connected to the outer wall of the ear.

[0010] In one embodiment of this utility model, in the extension direction of the blade, the positions where two adjacent upper sub-beams are spliced ​​are staggered with the positions where two adjacent lower sub-beams are spliced.

[0011] In one embodiment of this utility model, the top wall of the equal-strength connecting part is fixedly connected to the top wall of the connecting body by rivets.

[0012] In one embodiment of this utility model, the connecting lugs of the upper blade main beam and the connecting lugs of the lower blade main beam are fixedly connected by rivets.

[0013] In one embodiment of this utility model, the equal-strength connecting part and the connecting plate are fixed by welding.

[0014] In one embodiment of this utility model, a plurality of rivets for connecting the equal-strength connecting part and the connecting body are arranged in a rectangular pattern, the center distance between two adjacent rivets is 3 to 3.5 times the diameter of the rivet; the distance between the rivet and the edge of the equal-strength connecting part is 1.5 to 2 times the diameter of the rivet.

[0015] In one embodiment of this utility model, the equal-strength connecting part is integrally formed by bending process.

[0016] In one embodiment of this utility model, the thickness of the equal-strength connecting part is 11.5 mm to 13 mm.

[0017] In one embodiment of this utility model, the length of the equal-strength connection component extending into the upper or lower sub-beam is 220mm to 350mm.

[0018] In one embodiment of this utility model, the gap between the sidewall of the equal-strength connection part and the sidewall of the connection body is 0.2 mm to 0.5 mm.

[0019] This utility model also provides a wind turbine blade, comprising:

[0020] The rigid frame includes the blade main beam and multiple ribs in any of the above embodiments, with the multiple ribs spaced apart along the extension direction of the blade main beam.

[0021] A foam layer is filled within a rigid frame to form the shape of the blade.

[0022] The skin is laid on top of the foam layer.

[0023] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art:

[0024] The blade main beam and wind turbine blade of this utility model have an equal-strength connection part with the same shape inside the connecting body at the splicing position of multiple lower sub-beams and multiple upper sub-beams. The top wall of the equal-strength connection part is connected and fixed to the top wall of the connecting body. Due to the small space on the two side walls of the equal-strength connection part, the two side walls of the equal-strength connection part are connected by a connecting plate. This connection method does not damage the fatigue strength of the parent material (lower sub-beam and upper sub-beam). In addition, the upper and lower sub-beams of this application are integrally bent to form the connecting body and two connecting ears, reducing the number of connection nodes and ensuring the stability and strength of the structure. When the upper blade main beam and the lower blade main beam are connected, a stable connection is achieved through their respective connecting ears. It can be seen that the upper sub-beam, lower sub-beam and equal-strength connection component of this application are all integrally bent, reducing the number of connection nodes, maintaining the fatigue strength of the parent material, and ensuring the connection stability at the docking and splicing positions, thereby ensuring that the fatigue strength of the blade meets the requirements. Attached Figure Description

[0025] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0026] Figure 1 This is a schematic diagram of the structure of a wind turbine blade in a preferred embodiment of the present invention;

[0027] Figure 2 yes Figure 1 The diagram shows the structural schematic of the main blade beam in a wind turbine blade.

[0028] Figure 3 yes Figure 2 A partial schematic diagram; Figure 4 yes Figure 2 A cross-sectional view;

[0029] Figure 5 yes Figure 2 Longitudinal cross-sectional view;

[0030] Explanation of reference numerals in the accompanying drawings: 1000, blade main sparsity; 2000, foam layer; 3000, skin;

[0031] 100. Upper blade main beam; 110. Upper sub-beam; 111. Connecting body; 112. Connecting lug; 113. First rivet; 114. Second rivet;

[0032] 200. Lower blade main beam; 210. Lower sub-beam;

[0033] 300. Equal strength connection assembly; 310. Equal strength connection part; 320. Connection plate;

[0034] 400. Reinforcing components. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0036] Reference Figures 1-4 As shown, this utility model embodiment provides a wind turbine blade, including: a blade main beam 1000, multiple ribs, a foam layer 2000, and a skin 3000.

[0037] The blade main beam 1000 and multiple ribs form a rigid frame, with multiple ribs spaced apart along the extension direction of the blade main beam 1000.

[0038] The blade main beam 1000 includes an upper blade main beam 100, a lower blade main beam 200, and a strength-equal connecting assembly 300. The upper blade main beam 100 includes multiple spliced ​​upper sub-beams 110; the upper sub-beam 110 includes a C-shaped connecting body 111 and two connecting lugs 112; the connecting lugs 112 are formed by bending outwards from the ends of the connecting body 111. The lower blade main beam 200 includes multiple spliced ​​lower sub-beams 210; the lower sub-beam 210 has the same structure as the upper sub-beam 110; the upper blade main beam 100 and the lower blade main beam 200 are joined vertically, and their connecting lugs 112 are connected vertically. The connection is fixed; the equal strength connection component 300 includes a C-shaped equal strength connection part 310 and a connecting plate 320; the connecting plate 320 is connected to the opening of the equal strength connection part 310; two adjacent upper sub-beams 110 and two adjacent lower sub-beams 210 are spliced ​​by the equal strength connection component 300; at the splicing position, the equal strength connection component 300 is inserted into the interior of the connecting body 111, and the top wall of the equal strength connection part 310 is fixedly connected to the top wall of the connecting body 111.

[0039] A 2000-layer foam is filled into a rigid frame to form the shape of the blade.

[0040] The skin is 3000, laid on top of the foam layer 2000.

[0041] Specifically, in this embodiment, at the joint of multiple lower sub-beams 210 and multiple upper sub-beams 110, the interior of the connecting body 111 is provided with a strength-equal connecting portion 310 of the same shape. The top wall of the strength-equal connecting portion 310 is connected and fixed to the top wall of the connecting body 111. Due to the small space on the two side walls of the strength-equal connecting portion 310, the two side walls of the strength-equal connecting portion 310 are connected by a connecting plate 320. This connection method does not damage the fatigue strength of the parent material (lower sub-beam 210, upper sub-beam 110). In addition, the upper sub-beam 110 and lower sub-beam 210 of this application are integrally bent to form the connecting body 111 and two connecting ears 112, reducing connection nodes and ensuring the stability and strength of the structure. When the upper blade main beam 100 and the lower blade main beam 200 are joined, a stable connection is achieved through their respective connecting ears 112. As can be seen, the upper sub-beam 110, lower sub-beam 210, and equal-strength connection assembly 300 of this application are all integrally bent, which reduces the number of connection nodes and maintains the fatigue strength of the base material; and ensures the connection stability at the docking position and splicing position, so that the fatigue strength of the blade meets the requirements.

[0042] Furthermore, a reinforcing member 400 is attached to the outer wall of the connecting ear 112.

[0043] Specifically, in this embodiment, a reinforcing member 400 is added to further improve the connection strength at the docking position of the upper blade main beam 100 and the lower blade main beam 200.

[0044] Furthermore, in the extension direction of the blade, the splicing positions of two adjacent upper sub-beams 110 and the splicing positions of two adjacent lower sub-beams 210 are staggered.

[0045] Specifically, in this embodiment, the staggered arrangement of the splicing positions of the upper sub-beam 110 and the lower sub-beam 210 is an important measure to improve structural safety and reliability. Its core advantages are reflected in dispersing stress concentration, optimizing stress distribution, improving fatigue performance, and enhancing the overall structural integrity.

[0046] Furthermore, the top wall of the equal-strength connection portion 310 is fixedly connected to the top wall of the connection body 111 by the first rivet 113.

[0047] The connecting lug 112 of the upper blade main beam 100 and the connecting lug 112 of the lower blade main beam 200 are fixedly connected by a second rivet 114. When the present application includes a reinforcing member 400, at the upper and lower abutment positions of the upper blade main beam 100 and the lower blade main beam 200, the connecting lug 112 of the two and the reinforcing member 400 are connected by a second rivet 114.

[0048] Specifically, in this embodiment, the connection body 111 and the equal strength connection part 310 are achieved by the first rivet 113, and the connection lug 112 of the upper blade main beam 100 and the connection lug 112 of the lower blade main beam 200 are achieved by the second rivet 114, which can meet the fatigue strength requirements.

[0049] Furthermore, the equal-strength connection 310 and the connecting plate 320 are fixed by welding.

[0050] Specifically, since the connecting plate 320 provides tension to the two side walls of the connecting body 111, the equal-strength connecting assembly 300 becomes a closed frame structure, improving the stress resistance of the equal-strength connecting assembly 300. Therefore, the connection point between the connecting plate 320 and the equal-strength connecting part 310 is not a stress point of the blade, so the equal-strength connecting part 310 and the connecting plate 320 are fixed by welding, which does not affect the fatigue strength of the blade, and makes construction more convenient, faster, and less costly.

[0051] Furthermore, a plurality of first rivets 113 for connecting the equal-strength connecting portion 310 and the connecting body 111 are arranged in a rectangular pattern, with the center distance between two adjacent first rivets 113 being 3 to 3.5 times the rivet diameter; the distance of the first rivet 113 from the edge of the equal-strength connecting portion 310 is 1.5 to 3 times the rivet diameter. In some embodiments, the diameter of the first rivet 113 is 12 mm.

[0052] Furthermore, the equal-strength connecting part 310 is integrally formed through a bending process.

[0053] Specifically, in this embodiment, the fatigue performance of the integrally formed by bending is determined by the base material of the equal strength connection 310, thereby ensuring the fatigue strength of the equal strength connection 310.

[0054] Furthermore, the thickness of the equal-strength connection portion 310 is 11.5 mm to 13 mm. In some embodiments, the thickness of the equal-strength connection portion 310 is 12 mm.

[0055] Specifically, in this embodiment, the thickness of the equal-strength connection portion 310 facilitates the bending and forming of the equal-strength connection component 300, ensures its fatigue strength, and reduces costs.

[0056] In some embodiments, the thickness of the connecting plate 320 is 8mm to 13mm.

[0057] Furthermore, the length of the equal-strength connection component 300 extending into the upper sub-beam 110 or the lower sub-beam 210 is 220mm~350mm.

[0058] Specifically, this embodiment ensures the stability and reliability of the connection unit between two adjacent upper sub-beams 110 or two adjacent lower sub-beams 210, achieving the requirements of fatigue strength, while also reducing costs.

[0059] Furthermore, the gap between the sidewall of the equal-strength connection portion 310 and the sidewall of the connecting body 111 is 0.2 mm to 0.5 mm.

[0060] Specifically, this embodiment avoids interference between the sidewall of the equal-strength connection part 310 and the connecting body 111 caused by excessively small gaps; it also avoids reducing the connection reliability between the sidewall of the equal-strength connection part 310 and the sidewall of the connecting body 111 caused by excessively large gaps, thereby ensuring that the fatigue strength of the upper blade main beam 100 and the lower blade main beam 200 meets the requirements.

[0061] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A blade spar, characterized by: include: The upper blade main beam includes multiple spliced ​​upper sub-beams; the upper sub-beam includes a C-shaped connecting body and two connecting lugs; the connecting lugs are formed by bending outward from the end of the connecting body; The lower blade main beam includes multiple spliced ​​lower sub-beams; the lower sub-beams have the same structure as the upper sub-beams; the upper blade main beam and the lower blade main beam are connected vertically, and their connecting lugs are fixedly connected. An equal-strength connection assembly includes a C-shaped equal-strength connection part and a connecting plate; the connecting plate is connected to the opening of the equal-strength connection part. The two adjacent upper sub-beams and the two adjacent lower sub-beams are spliced ​​together by the equal strength connection components; at the splicing position, the equal strength connection components are inserted into the interior of the connecting body, and the top wall of the equal strength connection part is connected and fixed to the top wall of the connecting body.

2. Blade spar according to claim 1, characterized in that: The outer wall of the connecting ear is connected with a reinforcing member.

3. The blade main beam according to claim 1, characterized in that: In the extending direction of the blade, the positions where two adjacent upper sub-beams are spliced ​​together are staggered with the positions where two adjacent lower sub-beams are spliced ​​together.

4. The blade main beam according to claim 1, characterized in that: The top wall of the equal-strength connecting part is fixedly connected to the top wall of the connecting body by rivets; And / or, the connecting lugs of the upper blade main beam and the connecting lugs of the lower blade main beam are fixedly connected by rivets.

5. The blade main beam according to claim 1, characterized in that: The equal-strength connection part is fixed to the connection plate by welding.

6. The blade main beam according to claim 1, characterized in that: A plurality of rivets for connecting the equal-strength connecting part and the connecting body are arranged in a rectangular pattern, wherein the center distance between two adjacent rivets is 3 to 3.5 times the diameter of the rivet; and the distance between the rivet and the edge of the equal-strength connecting part is 1.5 to 2 times the diameter of the rivet.

7. The blade main beam according to claim 1, characterized in that: The equal-strength connecting part is integrally formed by bending process.

8. The blade main beam according to claim 1, characterized in that: The thickness of the equal-strength connection is 11.5 mm to 13 mm.

9. The blade main beam according to claim 1, characterized in that: The length of the equal-strength connecting component extending into the upper or lower sub-beam is 220mm to 350mm.

10. A wind turbine blade, characterized in that: include: A rigid frame includes a blade main beam and a plurality of ribs as described in any one of claims 1 to 9, wherein the plurality of ribs are spaced apart along the extension direction of the blade main beam; A foam layer is filled into the rigid frame to form the shape of the blade; The skin is laid on the foam layer.

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