Wind turbine blade root connection structure and wind turbine blade

Abstract

The present invention relates to the technical field of wind power generation, and specifically discloses a root connection structure of a wind turbine blade and a wind turbine blade. The root connection structure of the wind turbine blade includes a wedge block and a UD block; the wedge block includes a first body, the first body is a cylindrical structure, and a first inclined surface and a second inclined surface are arranged on the side surface of the first body, and both the first inclined surface and the second inclined surface intersect with the center line of the first body; the wedge block is located between two adjacent UD blocks, and the UD block includes a second body, and a third inclined surface corresponding to the first inclined surface and a fourth inclined surface corresponding to the second inclined surface are arranged on the second body. The root connection structure of the wind turbine blade can reduce stress concentration, reduce the risk of failure, and has a strong load-bearing capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and particularly to a root connection structure of a wind turbine blade and a wind turbine blade. Background Art

[0002] With the increasingly serious environmental pollution problems, the utilization of clean energy has received more and more attention. As an important clean energy, wind energy has been widely used. Wind turbine blades are important components of wind power generation equipment. Generally, the root of the wind turbine blade needs to be connected to the hub. In order to capture more wind energy to improve the power generation efficiency of the wind turbine, the size of the wind turbine blade is usually increased. However, as the size of the blade increases, the load borne by the root structure also continuously increases. In order to improve the load-bearing capacity of the root structure, the common methods in the prior art are: 1) increasing the diameter of the root and the number of bolts at the same time; 2) increasing the length of the bolts and the thickness of the root at the same time; 3) increasing the thickness of the fiber cloth and the diameter of the bolt sleeve at the same time. However, the above improvement methods will increase the use of raw materials in manufacturing the root structure, and thus increase the manufacturing cost of the wind turbine blade.

[0003] As Figure 1 and Figure 2 shown, on the wedge block 1' of the root structure in the prior art, there is an inclined surface 12'. The wedge block 1' is connected with the bolt sleeve in a matching manner. However, this asymmetric structure with only one inclined surface 12' usually has a large stress concentration, and is prone to failure risks, with low reliability. This design reduces the load-bearing capacity of the root structure to a certain extent.

[0004] Therefore, there is an urgent need to propose a root connection structure of a wind turbine blade to solve the above problems. Summary of the Invention

[0005] The first object of the present invention is to provide a root connection structure of a wind turbine blade, which can reduce stress concentration, reduce the risk of failure caused by stress concentration, and improve its own load-bearing capacity without increasing the amount of raw materials used.

[0006] The second object of the present invention is to provide a wind turbine blade. By applying the above root connection structure of the wind turbine blade, the blade size can be increased, thereby improving the power generation efficiency of the wind power equipment.

[0007] Based on the above concept, the technical solution adopted by the present invention is as follows:

[0008] The root connection structure of the wind turbine blade provided by the present invention includes:

[0009] Wedge block, the wedge block includes a first body, the first body is a cylindrical structure, a first inclined surface and a second inclined surface are arranged on the side surface of the first body, and both the first inclined surface and the second inclined surface intersect with the central line of the first body;

[0010] UD block, the wedge block is located between two adjacent UD blocks, the UD block includes a second body, and a third inclined surface corresponding to the first inclined surface and a fourth inclined surface corresponding to the second inclined surface are arranged on the second body.

[0011] As a preferred solution of the root connection structure of the wind turbine blade, the first inclined surface and the second inclined surface are symmetrically arranged with respect to the central line of the first body.

[0012] As a preferred solution of the root connection structure of the wind turbine blade, the cross-sectional shape of the first body is circular or polygonal.

[0013] As a preferred solution of the root connection structure of the wind turbine blade, a smooth transition is provided between the third inclined surface and the second body;

[0014] A smooth transition is provided between the fourth inclined surface and the second body.

[0015] As a preferred solution of the root connection structure of the wind turbine blade, the transition position between the third inclined surface and the second body is formed by a grinding process; and / or

[0016] The transition position between the fourth inclined surface and the second body is formed by a grinding process.

[0017] As a preferred solution of the root connection structure of the wind turbine blade, the root connection structure of the wind turbine blade further includes:

[0018] External ply structure;

[0019] A plurality of bolt sleeve assemblies are arranged at intervals along the circumferential direction of the external ply structure inside the external ply structure, and each bolt sleeve assembly is correspondingly connected to one wedge block.

[0020] As a preferred solution of the root connection structure of the wind turbine blade, the bolt sleeve assembly includes:

[0021] Bolt sleeve body;

[0022] A buffer layer is arranged on the outer circumference of the bolt sleeve body.

[0023] As a preferred solution of the root connection structure of the wind turbine blade, accommodation grooves are arranged on both sides of the second body, and the groove walls of the accommodation grooves can be attached to the outer walls of the corresponding bolt sleeve assemblies.

[0024] The present invention also provides a wind power blade, including the wind power blade root connection structure described in any of the above solutions.

[0025] The beneficial effects of the present invention are as follows:

[0026] For the wind power blade root connection structure provided by the present invention, by providing a first inclined surface and a second inclined surface on the first body of the wedge block, the risk of failure caused by stress concentration is reduced, and the load-bearing capacity of itself is improved without increasing the amount of processing raw materials of the wind power blade root connection structure; by providing a third inclined surface corresponding to the first inclined surface and a fourth inclined surface corresponding to the second inclined surface on the second body of the UD block, the angles of the above four inclined surfaces with the axis can be changed according to the root design requirements of the wind power blade, so as to better eliminate the stress concentration phenomenon and the bending effect of the blade root, improve the strength and fatigue stability of the wind power blade root connection structure, and thus improve the use reliability and service life of the wind power blade root connection structure.

[0027] For the wind power blade provided by the present invention, by applying the above wind power blade root connection structure, within the same load-bearing capacity range, the size of the blade can be increased, thereby improving the power generation efficiency of the wind power equipment. Description of the Drawings

[0028] Figure 1 is a schematic structural view of a wedge block of a wind power blade root connection structure provided by the prior art;

[0029] Figure 2 is a side view of a wedge block of a wind power blade root connection structure provided by the prior art;

[0030] Figure 3 is a schematic structural view of a wind power blade root connection structure provided by an embodiment of the present invention;

[0031] Figure 4 is a schematic cross-sectional view of a wind power blade root connection structure provided by an embodiment of the present invention;

[0032] Figure 5 is a schematic structural view of a wedge block provided by an embodiment of the present invention Figure 1 ;

[0033] Figure 6 is a side view of a wedge block provided by an embodiment of the present invention;

[0034] Figure 7 is a side view of a UD block provided by an embodiment of the present invention;

[0035] Figure 8 is a schematic cross-sectional view of a UD block provided by an embodiment of the present invention;

[0036] Figure 9It is a schematic structural diagram of a bolt sleeve assembly provided by an embodiment of the present invention;

[0037] Figure 10 It is a schematic cross-sectional view of a bolt sleeve body provided by an embodiment of the present invention;

[0038] Figure 11 It is a schematic structure of a wedge block provided by an embodiment of the present invention Figure 2 ;

[0039] Figure 12 It is a schematic cross-sectional view of the wedge block provided by an embodiment of the present invention.

[0040] In the figure:

[0041] 1'-wedge block; 12'-inclined surface;

[0042] 1-external paving layer structure; 11-upper paving layer; 12-lower paving layer;

[0043] 2-bolt sleeve assembly; 21-bolt sleeve body; 211-accommodation groove; 22-bushing nut;

[0044] 3-wedge block; 30-first body; 31-first inclined surface; 32-second inclined surface;

[0045] 4-UD block; 40-second body; 41-accommodation groove. Detailed implementation manners

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that, for the sake of description, only parts related to the present invention are shown in the drawings, rather than all structures.

[0047] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0048] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly under and obliquely under the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0049] In the description of this embodiment, the orientation or positional relationships such as "up", "down", "left" and "right" are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operations, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meanings.

[0050] As Figures 3 - 8 shown, this embodiment provides a root connection structure of a wind turbine blade. The root connection structure of the wind turbine blade includes an outer ply structure 1, a UD block 4, a wedge block 3 and a bolt sleeve assembly 2; a plurality of bolt sleeve assemblies 2 are arranged at intervals along the circumferential direction of the outer ply structure 1 inside the outer ply structure 1; each bolt sleeve assembly 2 corresponds to a wedge block 3, and the bolt sleeve assembly 2 is cooperatively connected with the corresponding wedge block 3; a UD block 4 is arranged between every two adjacent bolt sleeve assemblies 2. Among them, the UD block 4 is a unidirectional (Uni-Direction) block.

[0051] In order to improve the load-bearing capacity of the root connection structure of the wind turbine blade, in this embodiment, the wedge block 3 includes a first body 30. The first body 30 is of a cylindrical structure. A first inclined surface 31 and a second inclined surface 32 are arranged on the side surface of the first body 30, and the first inclined surface 31 and the second inclined surface 32 respectively intersect with the central axis of the first body 30; the wedge block 3 is located between two adjacent UD blocks 4. The UD block 4 includes a second body 40, and a third inclined surface corresponding to the first inclined surface 31 and a fourth inclined surface corresponding to the second inclined surface 32 are arranged on the second body 40.

[0052] The root connection structure of the wind turbine blade provided in this embodiment reduces the risk of failure caused by stress concentration by setting a first inclined surface 31 and a second inclined surface 32 on the first body 30, and improves its own load-bearing capacity without increasing the amount of processing raw materials of the root connection structure of the wind turbine blade; by setting a third inclined surface corresponding to the first inclined surface 31 and a fourth inclined surface corresponding to the second inclined surface 32 on the second body 40, the angles between the above four inclined surfaces and the axis can be changed according to the root design requirements of the wind turbine blade, which can better eliminate the stress concentration phenomenon and the bending effect of the blade root, improve the strength and fatigue stability of the root connection structure of the wind turbine blade, and thus improve the use reliability and service life of the root connection structure of the wind turbine blade.

[0053] Further, a smooth transition is provided between the third inclined surface and the second body 40; a smooth transition is provided between the fourth inclined surface and the second body 40. This design can reduce the stress concentration of the entire root connection structure of the wind turbine blade, further improve its load-bearing capacity, and at the same time improve its use reliability and service life.

[0054] Further, the first inclined surface 31 and the second inclined surface 32 are symmetrically arranged with respect to the center line of the first body 30. By adopting this arrangement, the entire root connection structure of the wind turbine blade can be symmetrically arranged, avoiding the stress concentration phenomenon caused by structural asymmetry, and further improving the use reliability and service life of the root connection structure of the wind turbine blade. Correspondingly, the third inclined surface and the fourth inclined surface are symmetrically arranged and respectively correspond to the first inclined surface 31 and the second inclined surface 32, so as to ensure that the first inclined surface 31 of the wedge block 3 and the third inclined surface of the UD block 4 are in the same plane, and the second inclined surface 32 of the wedge block 3 and the fourth inclined surface of the UD block 4 are in the same plane. Of course, in other embodiments, the angle between the first inclined surface 31 and the horizontal plane and the angle between the second inclined surface 32 and the horizontal plane can also be set to be unequal for adjustment according to the actual use environment, but it is necessary to ensure that the first inclined surface 31 of the wedge block 3 and the third inclined surface of the UD block 4 are in the same plane, and the second inclined surface 32 of the wedge block 3 and the fourth inclined surface of the UD block 4 are in the same plane, and the above effects can also be achieved.

[0055] It should be noted that the first inclined surface 31 and the second inclined surface 32 are symmetrically arranged along the up and down directions with the center line of the first body 30 as the axis of symmetry. As Figures 4 - 6 shown, the upper ply 11 is located above, and the lower ply 12 is located below, that is, the first inclined surface 31 faces the upper ply 11, and the second inclined surface 32 faces the lower ply 12.

[0056] Further, the transition position between the third inclined surface and the second body 40 is formed by a grinding process; and / or the transition position between the fourth inclined surface and the second body 40 is formed by a grinding process. The process operation is simple and the processing efficiency is relatively high.

[0057] Optionally, the wedge block 3 is made of PET (polyethylene terephthalate), PVC (polyvinyl chloride) or wood, which is beneficial to reducing the weight and processing cost while filling and fixing.

[0058] Furthermore, as Figure 3 shown, the outer ply structure 1 includes an upper ply 11 and a lower ply 12. The upper ply 11 is laid above the bolt sleeve assembly 2, and the lower ply 12 is laid below the bolt sleeve assembly 2. Optionally, both the upper ply 11 and the lower ply 12 are made of multi-axial fiberglass cloth. In this embodiment, the upper ply 11 and the lower ply 12 are preferably made of triaxial fiberglass reinforced plastic.

[0059] Furthermore, as Figure 4 and Figure 8 shown, accommodation grooves 41 are provided on both sides of the second body 40. The groove walls of the accommodation grooves 41 can be fitted with the outer walls of the corresponding bolt sleeve assemblies 2. With this arrangement, the two opposite accommodation grooves 41 on two adjacent second bodies 40 can form an accommodation space. The bolt sleeve assembly 2 is located in this accommodation space, and the outer wall of the bolt sleeve assembly 2 can be fitted with the cavity wall of the accommodation space, which is beneficial to increasing the contact area between the bolt sleeve assembly 2 and the UD block 4, and avoiding the formation of resin-rich accumulation or perfusion cavity around the bolt sleeve assembly 2, which affects the adhesion between the bolt sleeve assembly 2 and the surrounding materials and the service reliability of the root connection structure of the wind turbine blade.

[0060] Optionally, the UD block 4 is made of a mixed material of unidirectional fiberglass and epoxy resin or a mixed material of unidirectional fiberglass and polyurethane. Preferably, the UD block 4 is formed by pultrusion process.

[0061] Furthermore, as Figure 9 shown, the bolt sleeve assembly 2 includes a bolt sleeve body 21 and a buffer layer; the buffer layer is arranged on the outer periphery of the bolt sleeve body 21. Optionally, the buffer layer is untwisted roving wound around the outer periphery of the bolt sleeve body 21.

[0062] After the screw connector extends into the bolt sleeve body 21, it is sealed by the sleeve nut 22, so as to prevent resin from invading the bolt sleeve body 21 during the perfusion process.

[0063] Preferably, a receiving groove 211 is provided on the outer peripheral surface of the bolt sleeve body 21, and the buffer layer is received in the receiving groove 211. The receiving groove 211 on the bolt sleeve body 21 provides a receiving space for the arrangement of the buffer layer. Further preferably, the receiving groove 211 is arranged in a spiral shape on the bolt sleeve body 21. This design can make the untwisted roving wind around the outer periphery of the bolt sleeve body 21 in sequence, improving the winding efficiency.

[0064] Optionally, in this embodiment, the cross-sectional shape of the first body 30 is circular or polygonal. As Figure 5 shown, the cross-sectional shape of the first body 30 is circular. Correspondingly, the cross-sectional shape of the bolt sleeve body 21 is circular; the receiving groove 41 on the second body 40 is an arc groove to stably receive the bolt sleeve body 21 and the first body 30. In another embodiment, as Figures 7 - 12 shown, the cross-sectional shape of the first body 30 is octagonal. Correspondingly, the cross-sectional shape of the bolt sleeve body 21 is octagonal; the shape of the receiving groove 41 on the second body 40 is adapted to the outer peripheral surface of the first body 30 and the outer peripheral surface of the bolt sleeve body 21 to stably receive the bolt sleeve body 21 and the first body 30. Of course, in other embodiments, the cross-sectional shape of the first body 30 can also be hexagonal or other shapes. Correspondingly, the cross-sectional shape of the bolt sleeve body 21 is the same as the cross-sectional shape of the first body 30, and the shape of the receiving groove 41 on the second body 40 is adapted to the outer peripheral surface of the first body 30 and the outer peripheral surface of the bolt sleeve body 21.

[0065] Next, the manufacturing method of the root connection structure of the wind turbine blade will be briefly described in conjunction with Figures 3 - 12 ;

[0066] (1) Manufacture a preform using a composite pultrusion process, cut the preform according to a preset shape and size to form a wedge block 3 and a UD block 4, and polish the fillets at the transition positions between the third inclined surface of the UD block 4 and the second body 40 and between the fourth inclined surface and the second body 40;

[0067] (2) Wind roving on the outer periphery of the bolt sleeve body 21 using an automatic device to form a buffer layer;

[0068] (3) Lay a three-axis fiberglass layer in the blade mold to form a lower ply 12;

[0069] (4) Connect the bolt sleeve assembly 2 to the blade root steel flange using fixing bolts, and place the UD block 4, wedge block 3, and small tow roving;

[0070] (5) Lay a three-axis fiberglass layer above the bolt sleeve assembly 2 to form an upper ply 11;

[0071] (6) Lay a diversion and vacuum system;

[0072] (7) Infuse epoxy resin and heat cure to bond all components into a whole;

[0073] (8) Demold the blade and grind and trim the root;

[0074] (9) Screw a screw connector into the bolt sleeve body 21 and connect it to the wind turbine hub to form a complete wind power equipment.

[0075] This embodiment also provides a wind turbine blade. By applying the above-mentioned root connection structure of the wind turbine blade, within the range of the same load-bearing capacity, the size of the blade can be increased, thereby improving the power generation efficiency of the wind power equipment.

[0076] The above embodiments only illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, there are various changes and modifications to the present invention, and these changes and modifications all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. Wind turbine blade root connection structure, characterized in that, Comprising: A wedge block (3), the wedge block (3) includes a first body (30), the first body (30) is a cylindrical structure, a first inclined surface (31) and a second inclined surface (32) are provided on the side surface of the first body (30), and both the first inclined surface (31) and the second inclined surface (32) intersect with the center line of the first body (30); A UD block (4), the wedge block (3) is located between two adjacent UD blocks (4), the UD block (4) includes a second body (40), and a third inclined surface corresponding to the first inclined surface (31) and a fourth inclined surface corresponding to the second inclined surface (32) are provided on the second body (40).

2. The wind turbine blade root connection structure according to claim 1, characterized in that The first inclined surface (31) and the second inclined surface (32) are symmetrically arranged with respect to the center line of the first body (30).

3. The wind turbine blade root connection structure according to claim 1, characterized in that, The cross-sectional shape of the first body (30) is circular or polygonal.

4. The root connection structure of a wind turbine blade according to claim 1, characterized in that, The third inclined surface is smoothly transitioned with the second body (40); The fourth inclined surface is smoothly transitioned with the second body (40).

5. The wind turbine blade root connection structure according to claim 4, characterized in that, The transition position between the third inclined surface and the second body (40) is formed by a grinding process; and / or The transition position between the fourth inclined surface and the second body (40) is formed by a grinding process.

6. The root connection structure of a wind turbine blade according to claim 1, characterized in that, The wind turbine blade root connection structure further comprises: An outer ply structure (1); A plurality of bolt sleeve assemblies (2), which are arranged at intervals along the circumference of the outer ply structure (1) inside the outer ply structure (1), and each bolt sleeve assembly (2) is correspondingly connected to one wedge block (3).

7. The wind turbine blade root connection structure according to claim 6, characterized in that, The bolt sleeve assembly (2) includes: A bolt sleeve body (21); A buffer layer, which is arranged on the outer periphery of the bolt sleeve body (21).

8. The wind turbine blade root connection structure according to claim 6, wherein, Accommodating grooves (41) are provided on both sides of the second body (40), and the groove walls of the accommodating grooves (41) can be attached to the outer walls of the corresponding bolt sleeve assemblies (2).

9. Wind turbine blade, characterized in that, Including the wind turbine blade root connection structure according to any one of claims 1-8.

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