CN114347576B

CN114347576B - Main beam of blade and blade

Info

Publication number: CN114347576B
Application number: CN202111640390.5A
Authority: CN
Inventors: 李正浛; 袁渊
Original assignee: Jiangsu Goldwind Science and Technology Co Ltd
Current assignee: Jiangsu Goldwind Science and Technology Co Ltd
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2023-06-27
Anticipated expiration: 2041-12-29
Also published as: CN114347576A

Abstract

The invention provides a main beam of a blade and the blade. The girder includes first fibrous layer and second fibrous layer, first fibrous layer with the second fibrous layer is followed the root of girder is towards the tip of girder sets gradually, first fibrous layer includes glass fiber, the second fibrous layer includes carbon fiber, the specific stiffness of second fibrous layer is greater than the specific stiffness of first fibrous layer. According to the main beam disclosed by the invention, the interference of excessive deflection of the blade tip and the tower frame can be avoided, the risk of sweeping the tower by the blade is reduced, the main beam of the blade tip section can meet the requirements of strength and rigidity, meanwhile, the weight of the blade, especially the weight of the blade tip, can be reduced, the manufacturing cost of the blade can be reduced, and the resonance between the blade and the tower frame can be avoided.

Description

Main beam of blade and blade

Technical Field

The invention relates to the technical field of wind generating sets, in particular to a main beam of a blade and the blade.

Background

The wind generating set is used for converting wind energy into electric energy. Currently, as the single-machine capacity of wind generating sets is increased, longer blades are required to capture wind energy for conversion into electrical energy.

The blade comprises a suction side shell and a pressure side shell which are glued together, and a main beam and a web which are load bearing components. As the blades become longer and longer, the length of the spar and web become longer and longer, and the materials of the spar and web have an effect on the weight, strength, rigidity, cost, etc. of the blade, so it is necessary to design the spar and web in consideration of the above factors.

Disclosure of Invention

The invention aims to provide a girder and a blade which can avoid interference between overlarge deflection of the blade tip of the blade and a tower and reduce risk of sweeping the tower.

Another object of the present invention is to provide a spar and blade that are lightweight, high strength and high stiffness.

Another object of the present invention is to provide a girder and a blade that can effectively avoid resonance between the natural frequency of the blade and the frequency of the tower.

According to an aspect of the present invention, there is provided a spar of a blade, the spar comprising a first fibre layer and a second fibre layer, the first fibre layer and the second fibre layer being arranged in sequence from a root portion of the spar towards a tip portion of the spar, the first fibre layer comprising glass fibres, the second fibre layer comprising carbon fibres, the second fibre layer having a specific stiffness which is greater than the specific stiffness of the first fibre layer. According to the main beam disclosed by the invention, the interference of excessive deflection of the blade tip and the tower frame can be avoided, the risk of sweeping the tower by the blade is reduced, the main beam of the blade tip section can meet the requirements of strength and rigidity, meanwhile, the weight of the blade, especially the weight of the blade tip, can be reduced, the manufacturing cost of the blade can be reduced, and the resonance between the blade and the tower frame can be avoided.

Optionally, the first fibrous layer is staggered from the second fibrous layer and overlapped together to form an overlap region, thereby joining the first fibrous layer and the second fibrous layer as a unit.

Optionally, the overlap length of the first fibrous layer and the second fibrous layer is between 10cm and 50 cm. If the overlap length is less than 10cm, the strength of the main girder at the overlap is insufficient, and if the overlap length is more than 50cm, the weight of the main girder is increased.

Optionally, the first fiber layer and the second fiber layer are overlapped in a step mode. By this arrangement, the thickness of the main beam in the overlap region of the first and second fibre layers is prevented from becoming too thick.

Optionally, the first fiber layer has a lower fiber density in the overlap region than in other regions of the first fiber layer, and the second fiber layer has a lower fiber density in the overlap region than in other regions of the second fiber layer. By this arrangement too thick girders in the overlap area of the first fibre layer and the second fibre layer can be avoided.

Optionally, the first fiber layer comprises only glass fibers and the second fiber layer comprises only carbon fibers. By the arrangement, the rigidity of the main girder of the blade tip area can be further improved, so that the effect of reducing the risk of blade tower sweeping is optimized.

Optionally, the first fiber layer comprises only glass fibers and the second fiber layer comprises both glass fibers and carbon fibers. By the arrangement, the manufacturing cost of the main beam can be reduced while the blade sweeping tower is prevented.

Optionally, the first fiber layer includes both glass fibers and carbon fibers, and the second fiber layer includes both glass fibers and carbon fibers, and the weight of carbon fibers per unit volume of the second fiber layer is greater than the weight of carbon fibers per unit volume of the first fiber layer. By this arrangement, the weight of the blade can be further reduced while preventing the blade from sweeping the tower.

Optionally, in the first fiber layer, the glass fibers and the carbon fibers are arranged in any one of the following manners: the glass fibers and the carbon fibers are arranged in a staggered manner in the thickness direction of the main beam, the glass fibers are arranged above the carbon fibers, and the glass fibers are arranged below the carbon fibers.

Optionally, in the second fiber layer, the glass fibers and the carbon fibers are arranged in any one of the following manners: the glass fibers and the carbon fibers are arranged in a staggered manner in the thickness direction of the main beam, the glass fibers are arranged above the carbon fibers, and the glass fibers are arranged below the carbon fibers.

Optionally, the main beam comprises a first main beam section and a second main beam section connected to each other, the first main beam section comprising the first fiber layer and the second main beam section comprising the second fiber layer.

Optionally, the first girder segment and the second girder segment are adhered to each other by an adhesive layer, and a bonding surface of the first girder segment and the second girder segment is an inclined surface to increase an adhesive area between the first girder segment and the second girder segment and improve adhesive force.

Optionally, reinforcing layers are disposed on two sides of the bonding areas of the first main beam section and the second main beam section, so as to improve bonding strength of the first main beam section and the second main beam section.

Optionally, the second fiber layer is disposed from the tip of the main beam to more than 1/3 of the length of the main beam.

According to another aspect of the present invention there is provided a blade comprising a spar as described above.

Optionally, the blade further comprises a blade root preform comprising a fibre layer comprising glass fibres and carbon fibres. According to the present invention, by making the fiber layer include both glass fibers and carbon fibers, the following technical effects can be achieved at the same time: the strength requirements of the blade root prefabricated part are met, and the fracture risk, manufacturing cost and weight of the blade root prefabricated part are reduced.

Optionally, the blade root prefabricated member comprises a bolt sleeve arranged along the circumferential direction, the fiber layer comprises an inner fiber layer arranged on the radial inner side of the bolt sleeve and an outer fiber layer arranged on the radial outer side of the bolt sleeve, the inner fiber layer is glass fiber, and the outer fiber layer is carbon fiber. Or, the inner fiber layer is carbon fiber, and the outer fiber layer is glass fiber. Alternatively, the inner and outer fiber layers each comprise glass fibers and carbon fibers.

Optionally, in each of the inner and outer fiber layers, glass fibers and carbon fibers are arranged in staggered layers.

Optionally, the blade further comprises a main beam lower layer and a main beam upper layer, wherein the main beam lower layer is arranged on the outer side of the main beam, the main beam upper layer is arranged on the inner side of the main beam, each of the main beam lower layer and the main beam upper layer comprises carbon fibers and glass fibers, the carbon fibers and the glass fibers are sequentially arranged from the blade root of the blade towards the blade tip of the blade, and the carbon fibers are arranged from the blade root of the blade to 1/4-1/3 of the length of the blade. Through the arrangement, the structural strength of the blade root section with concentrated load can be improved, and the weight and manufacturing cost of the whole blade can be reduced.

Optionally, in each of the main beam lower ply and the main beam upper ply, the carbon fibers and the glass fibers overlap in a step-like manner.

Optionally, the blade comprises two main beams, one of the two main beams comprising the first fiber layer and the second fiber layer, and the first fiber layer comprising only glass fibers, the second fiber layer comprising only carbon fibers, and the fiber layer of the other of the two main beams comprising only glass fibers.

Optionally, the blade further includes a web, the web includes a core material and reinforcing portions respectively disposed at two sides of the core material, at least one of the reinforcing portions includes a third fiber layer and a fourth fiber layer, the third fiber layer and the fourth fiber layer are sequentially disposed from a root portion of the web toward a tip portion of the web, the third fiber layer includes glass fibers, the fourth fiber layer includes carbon fibers, and a specific stiffness of the fourth fiber layer is greater than a specific stiffness of the third fiber layer. Through the arrangement, the blade tip deflection is prevented from being too large to interfere with the tower, the risk of sweeping the tower by the blade is reduced, the web plate of the blade tip section meets the requirements of strength and rigidity, the weight of the web plate can be reduced, the manufacturing cost of the web plate can be reduced, and the blade and the tower are prevented from resonating.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic illustration of the installation of a spar and web in a blade according to an embodiment of the present invention;

FIG. 2 is a schematic view of a main beam and web according to an embodiment of the invention;

FIG. 3 is a schematic illustration of the arrangement of fiber layers in a main beam according to one embodiment of the invention;

FIG. 4 is a schematic illustration of the arrangement of fiber layers in a main beam according to another embodiment of the invention;

FIG. 5 is a schematic view of a spar for a segmented blade according to an embodiment of the present invention;

FIG. 6 is a chordwise cross-sectional view of a web according to an embodiment of the invention;

FIG. 7 is a spanwise cross-sectional view of a web according to an embodiment of the invention;

fig. 8 to 10 are schematic views of a blade root preform according to an embodiment of the invention;

FIG. 11 is a schematic view of a blade according to one embodiment of the invention.

Reference numerals illustrate: 10 is a main beam, 10a is a first main beam section, 10b is a second main beam section, 10c is an adhesive layer, 10d is a reinforcing layer, 11 is a first fiber layer, 12 is a second fiber layer, 20 is a web, 21 is a core material, 22 is a reinforcing part, 22a is a third fiber layer, 22b is a fourth fiber layer, 30 is a blade root prefabricated part, 31 is a bolt sleeve, 32 is an inner fiber layer, 33 is an outer fiber layer, 34 is a blocking piece, 35 is an oblique angle transition piece, 100 is a blade, 101 is a pressure surface shell, and 102 is a suction surface shell.

Detailed Description

FIG. 1 is a schematic illustration of the installed condition of a spar and web in a blade according to an embodiment of the present invention. Fig. 1 shows a schematic view of a part of a blade in an open state of a Suction Side (SS) shell and a Pressure Side (PS) shell.

As shown in FIG. 1, blade 100 may include a pressure side shell 101 and a suction side shell 102. In the installed blade 100, the pressure side shell 101 and the suction side shell 102 may be bonded to each other, for example by cementing, to form a complete shell providing a geometric airfoil through which the airflow passes.

According to an embodiment of the invention, the blade 100 may further comprise a spar 10. The main beams 10 may be provided in the pressure side shell 101 and the suction side shell 102 as load bearing members. The blade 100 may comprise two spar 10 arranged in a pressure side shell 101 and a suction side shell 102, respectively.

The blade 100 may also include a web 20. The web 20 may be supported between the pressure side shell 101 and the suction side shell 102 for withstanding shear and bending moments. Alternatively, the blade 100 may include two webs 20, the two webs 20 being separated from each other. However, the number of the webs 20 is not particularly limited.

Fig. 2 is a schematic view of a main beam and web according to an embodiment of the invention. As shown in fig. 2, the two main beams 10 are opposed to each other in the thickness direction of the blade 100, and the two webs 20 are opposed to each other in the chord direction of the blade 100 and support the two main beams 10.

Main beams according to embodiments of the invention

Hereinafter, the girder 10 of the blade 100 according to the embodiment of the present invention will be described first with reference to fig. 3 to 5.

Fig. 3 is a schematic view of the arrangement of the fibre layers in the spar according to one embodiment of the invention, fig. 4 is a schematic view of the arrangement of the fibre layers in the spar according to another embodiment of the invention, and fig. 5 is a schematic view of a spar for a segmented blade according to an embodiment of the invention.

As shown in fig. 3 and 4, at least one of the two girders 10 includes a first fiber layer 11 and a second fiber layer 12 according to an embodiment of the present invention. The first fiber layer 11 and the second fiber layer 12 are disposed in this order from the root of the girder 10 (the end of the girder 10 near the root of the blade 100) toward the tip of the girder 10 (the end of the girder near the tip of the blade 100), the first fiber layer 11 comprising glass fibers, the second fiber layer 12 comprising carbon fibers, the second fiber layer 12 having a specific stiffness greater than that of the first fiber layer 11.

That is, the first fiber layer 11 corresponding to the She Genduan of the blade 100 (the region from the root of the blade 100 to the middle portion of the blade 100) includes glass fibers, the second fiber layer 12 corresponding to the tip section of the blade 100 (the region from the middle portion of the blade 100 to the tip of the blade 100) includes carbon fibers, and the specific stiffness of the second fiber layer 12 corresponding to the tip section of the blade 100 is greater than the specific stiffness of the first fiber layer 11 corresponding to the root section of the blade 100. According to the embodiment of the present invention, by the above structure, the following four technical effects can be achieved.

First, since the second fiber layer 12 includes carbon fibers, and the specific stiffness of the second fiber layer 12 is greater than the specific stiffness of the first fiber layer 11, the stiffness of the tip section of the blade 100 may be improved, so that excessive tip deflection and tower interference may be avoided, and the risk of blade tower sweeping may be reduced.

Second, for a wind turbine blade, the relative thickness from the blade to the tip airfoil (maximum height/chord of the airfoil) typically does not exceed 30%, i.e., the cavity space in the blade to the tip is small, and the spar is required to meet the strength and stiffness requirements in the small space, so by including carbon fibers in the second fiber layer 12 corresponding to the tip section of the blade 100, the tip section spar can meet the strength and stiffness requirements while reducing the weight of the spar, particularly the tip section spar.

Third, in the prior art, the girder may be entirely made of carbon fiber, however, in this case, the manufacturing cost of the girder increases greatly, and according to an embodiment of the present invention, the manufacturing cost of the girder may be reduced by applying glass fiber to the girder 10 corresponding to the root section of the blade 100.

Fourth, by applying carbon fibers in the spar 10 corresponding to the tip section of the blade 100, the natural frequency of the blade 100 may be increased by the high frequency characteristics of the carbon fibers themselves, avoiding resonance of the blade 100 with the tower.

According to an embodiment of the present invention, "at least one of the two girders 10 comprises a first fiber layer 11 and a second fiber layer 12" may comprise the following: both girders 10 comprise a first fibre layer 11 and a second fibre layer 12; one of the two girders 10 comprises a first fibre layer 11 and a second fibre layer 12, the other of the two girders 10 comprises other forms of fibre layers.

According to an embodiment of the invention, the first fibre layer 11 comprises glass fibres. Wherein the main components of the glass fiber are silicon dioxide, aluminum oxide, calcium oxide, boron oxide, magnesium oxide, sodium oxide and the like. According to the content of alkali in glass, alkali-free glass fibers (E glass fibers for short, sodium oxide 0% -2% and belongs to aluminoborosilicate glass), medium alkali glass fibers (sodium oxide 8% -12% and belongs to sodium-calcium silicate glass containing boron or not) and high alkali glass fibers (sodium oxide more than 13% and belongs to sodium-calcium silicate glass) can be classified.

According to an embodiment of the invention, the second fibrous layer 12 comprises carbon fibers. The carbon fiber is a special fiber including carbon element. The carbon fiber has the characteristics of high temperature resistance, friction resistance, electric conduction, heat conduction, corrosion resistance and the like, is fibrous in shape, soft and can be processed into various fabrics, and the graphite microcrystalline structure of the carbon fiber has high strength and modulus along the fiber axis direction because of the preferential orientation along the fiber axis. The carbon fibers have a low density and thus have a high specific strength and a high specific modulus.

In addition, it should be understood that the specific stiffness of the first fibrous layer 11 and the specific stiffness of the second fibrous layer 12 refer to the average specific stiffness of the first fibrous layer 11 and the average specific stiffness of the second fibrous layer 12. That is, when the first fiber layer 11 has a plurality of fiber layers and the second fiber layer 12 has a plurality of fiber layers, the specific stiffness of the first fiber layer 11 means an average value of the rigidities of the plurality of fiber layers of the first fiber layer 11, and the specific stiffness of the second fiber layer 12 means an average value of the rigidities of the plurality of fiber layers of the second fiber layer 12.

According to an embodiment of the present invention, the first fiber layer 11 may include only glass fibers, and the second fiber layer 12 may include only carbon fibers. By this arrangement, the stiffness of the blade tip region main beam 10 can be further increased, thus optimizing the effect of reducing the risk of blade tower sweeping.

Alternatively, according to an embodiment of the present invention, the first fiber layer 11 may include only glass fibers, and the second fiber layer 12 may include both glass fibers and carbon fibers. By the arrangement, the manufacturing cost of the main beam can be reduced while the blade sweeping tower is prevented.

Alternatively, according to an embodiment of the present invention, the first fiber layer 11 includes both glass fibers and carbon fibers, the second fiber layer 12 includes both glass fibers and carbon fibers, and the weight of the carbon fibers per unit volume of the second fiber layer 12 is greater than the weight of the carbon fibers per unit volume of the first fiber layer 11. That is, in the case where both the first fiber layer 11 and the second fiber layer 12 include glass fibers and carbon fibers, the arrangement density of the carbon fibers in the second fiber layer 12 is higher than that in the first fiber layer 11 so that the specific stiffness of the second fiber layer is higher than that of the first fiber layer. By the arrangement, compared with the blade root section of the main beam 10, the rigidity of the blade tip section of the main beam 10 can be further improved, so that the tower sweeping accident is avoided.

According to an embodiment of the present invention, when the first fiber layer 11 includes both glass fibers and carbon fibers, the glass fibers and the carbon fibers are arranged in any one of the following ways: the glass fibers and the carbon fibers are arranged in staggered layers in the thickness direction of the blade girder, the glass fibers are arranged above the carbon fibers, and the glass fibers are arranged below the carbon fibers. Wherein "above" and "below" are determined based on fig. 3 and 4, and "above" in fig. 3 and 4 may refer to an area near the exterior of the blade, and "below" may refer to an area near the interior of the blade.

In addition, according to an embodiment of the present invention, when the second fiber layer 12 includes both glass fibers and carbon fibers, the glass fibers and the carbon fibers are arranged in any one of the following ways: the glass fibers and the carbon fibers are arranged in staggered layers in the thickness direction of the blade girder, the glass fibers are arranged above the carbon fibers, and the glass fibers are arranged below the carbon fibers. "above" and "below" are to be understood in a similar manner to the above description.

According to an embodiment of the invention, when the blade 100 comprises two spar 10, each spar 10 of the two spar 10 may comprise a first fibre layer 11 and a second fibre layer 12 in the manner described above. And the first fiber layer 11 comprises only glass fibers and the second fiber layer 12 comprises only carbon fibers. By the arrangement, the rigidity of the main girder of the blade tip section can be further improved.

According to another embodiment of the invention, when the blade 100 comprises two spar 10, one spar 10 of the two spar 10 comprises a first fibre layer 11 and a second fibre layer 12, and the first fibre layer 11 comprises only glass fibres and the second fibre layer 12 comprises only carbon fibres, the other spar 10 of the two spar 10 also comprises fibre layers, but its fibre layers comprise only glass fibres and not carbon fibres. By such an arrangement, the stiffness of the tip section of the spar 10 may be increased while further reducing the manufacturing costs of the spar 10.

According to an embodiment of the present invention, since the girder is required to withstand the tensile and bending moments of the blade, the second fiber layer 12 including carbon fibers may be disposed from the tip portion of the girder 10 up to more than 1/3 of the length of the girder 10. The first fibre layer 11 may be arranged from the root of the main beam 10 to the area overlapping the second fibre layer 12.

As shown in fig. 3 and 4, the first fiber layer 11 and the second fiber layer 12 are disposed in a staggered manner and overlapped together to form an overlapped region, thereby connecting the first fiber layer 11 and the second fiber layer 12 as a single body.

According to an embodiment of the present invention, since the main girder needs to withstand the tensile force and bending moment of the blade, in order to secure the lapping quality, the lapping length of the first fiber layer 11 and the second fiber layer 12 (referred to as the lapping length formed by a single layer of the first fiber layer 11 and a single layer of the second fiber layer 12) is between 10cm and 50 cm. If the overlap length is less than 10cm, the strength of the girder 10 is insufficient at the overlap, and if the overlap length is more than 50cm, the weight of the girder 10 is increased.

According to an embodiment of the present invention, as shown in fig. 4, the first fiber layer 11 and the second fiber layer 12 may be overlapped in a stepped manner. By this arrangement, the thickness of the girder 10 is prevented from being excessively thick in the overlap region of the first and second fiber layers 11 and 12.

In addition, the thickness of the main beam in the overlap region can be reduced by reducing the fiber density of the first fiber layer 11 and the second fiber layer 12 in the overlap region. Specifically, the thickness of the fiber layers is related to the density of the fiber layers, and as the density of the fiber layers increases, the thickness of the girder 10 is prevented from being excessively thick in the overlap region of the first and second fiber layers 11 and 12 by reducing the fiber density of the first and second fiber layers 11 and 12 in the overlap region. Thus, according to embodiments of the present invention, the fiber density of the first fiber layer 11 in the overlap region may be made lower than the fiber density of the first fiber layer 11 in other regions, and the fiber density of the second fiber layer 12 in the overlap region may be made lower than the fiber density of the second fiber layer 12 in other regions.

It should be appreciated that while only three layers of first and second fiber layers 11 and 12 are shown in fig. 3 and 4, fig. 3 and 4 are merely examples, and the specific number of layers of first and second fiber layers 11 and 12 of spar 10 is not particularly limited and may be designed according to the overall structural design of blade 100.

According to an embodiment of the present invention, the girder 10 may further include a resin coating the first and second fiber layers 11 and 12 to mold the first and second fiber layers 11 and 12. Accordingly, in fig. 3 and 4, the cured resin is provided between the adjacent fiber layers of the first fiber layer 11 and the second fiber layer 12.

As an example, the main beam 10 in fig. 3 and 4 may be manufactured by any one of the following ways: first, paving a first fiber layer 11 and a second fiber layer 12 in a girder die, and then pouring resin into the first fiber layer 11 and the second fiber layer 12 and curing and forming; or the first fiber layer 11 and the second fiber layer 12 can be manufactured into fiber prepregs, and then the fiber prepregs are laid in a girder mould for solidification and molding; alternatively, a pultruded panel of the first fiber layer 11 and the second fiber layer 12 may be manufactured and then laid down to shape.

The spar 10 according to embodiments of the present invention may also be adapted for use with segmented blades. Fig. 5 is a schematic view of a spar 10 for a segmented blade according to an embodiment of the present invention. As shown in fig. 5, the main beam 10 may include a first main beam section 10a and a second main beam section 10b. The first and second

main girder segments

10a and 10b may be connected to each other by an adhesive layer 10c and a reinforcing layer 10 d.

According to an embodiment of the present invention, the bonding surfaces of the first and

second girder segments

10a and 10b (i.e., the end surfaces of the first and

second girder segments

10a and 10 b) may be inclined surfaces to increase the bonding area between the first and

second girder segments

10a and 10b and to improve the bonding force. The adhesive layer 10c may be formed using a material having adhesive properties, and alternatively, the adhesive layer 10c may include a structural adhesive.

According to an embodiment of the present invention, in order to improve the bonding strength of the first and

second girder segments

10a and 10b, a reinforcing layer 10d may be further provided at both sides of the bonding region of the girder 10. As an example, the reinforcing layer 10d may be a resin-impregnated fiber.

However, the present invention is not limited thereto, and when the adhesive strength of the adhesive layer 10c is sufficient, the first and

second girder segments

10a and 10b may be connected only by the adhesive layer 10 c.

Additionally, although not shown, the first and second

main beam sections

10a, 10b may also be connected to one another by mechanical connectors (e.g., bolts).

According to embodiments of the present invention, the first main beam section 10a may include a first fiber layer 11, the second main beam section 10b may include a second fiber layer 12, and specific materials of the first fiber layer 11 and the second fiber layer 12 may be the same as those described above with reference to fig. 3 and 4, and for redundancy avoidance, a repeated description is not provided herein.

According to an embodiment of the invention, the second girder segment 10b may be provided from the tip of the girder 10 up to more than 1/3 of the length of the girder 10.

As an example, the main beam 10 in fig. 5 may be manufactured by: the first girder segment 10a may be manufactured using the first fiber layer 11, the second girder segment 10b may be manufactured using the second fiber layer 12, and then the first girder segment 10a and the second girder segment 10b may be connected to each other. In manufacturing the first main girder segment 10a, the first fiber layer 11 may be laid down and then poured with resin and cured to shape, or the first fiber layer 11 may be manufactured as a fiber prepreg and then cured to shape, or a pultruded panel of the first fiber layer 11 may be manufactured and then laid down to shape. The second main beam section 10b may be manufactured in a similar manner.

According to the girder provided by the embodiment of the invention, the technical effects of four aspects can be simultaneously realized: 1. the blade tip deflection is prevented from being too large to interfere with the tower, and the risk of sweeping the tower by the blade is reduced; 2. the main beam of the blade tip section meets the requirements of strength and rigidity, and meanwhile, the weight of the main beam, particularly the weight of the main beam of the blade tip area, can be reduced; 3. the manufacturing cost of the main beam can be reduced; 4. avoiding resonance of the blade and the tower.

Webs according to embodiments of the invention

Hereinafter, a web according to an embodiment of the present invention will be described with reference to fig. 6 and 7. Fig. 6 is a chordwise cross-sectional view of a web according to an embodiment of the invention, and fig. 7 is a spanwise cross-sectional view of a web according to an embodiment of the invention.

As shown in fig. 6 and 7, the web 20 according to an embodiment of the present invention may include a core 21 and reinforcing parts 22 disposed at both sides of the core 21, respectively.

According to the embodiment of the present invention, the reinforcing parts 22 provided at both sides of the core 21 are bonded together at both ends of the core 21 and bent in one direction, so that the web 20 as a whole forms a box-like structure like a C-shape to provide strength and rigidity of the blade.

According to an embodiment of the present invention, at least one of the two reinforcing parts 22 disposed at both sides of the core material 21 may include a third fiber layer 22a and a fourth fiber layer 22b. The third fiber layer 22a and the fourth fiber layer 22b are disposed in this order from the root of the web 20 (the end of the web 20 near the root of the blade 100) toward the tip of the web 20 (the end of the web 20 near the tip of the blade 100), the third fiber layer 22a includes glass fibers, the fourth fiber layer 22b includes carbon fibers, and the specific stiffness of the fourth fiber layer 22b is greater than that of the third fiber layer 22 a.

That is, the third fiber layer 22a corresponding to the She Genduan of the blade 100 (the region from the root of the blade 100 to the middle portion of the blade 100) includes glass fibers, the fourth fiber layer 22b corresponding to the tip section of the blade 100 (the region from the middle portion of the blade 100 to the tip of the blade 100) includes carbon fibers, and the specific stiffness of the fourth fiber layer 22b is greater than the specific stiffness of the third fiber layer 22 a. According to the embodiment of the present invention, by the above structure, the following four technical effects can be achieved.

First, because the fourth fiber layer 22b includes carbon fibers and the specific stiffness of the fourth fiber layer 22b is greater than the specific stiffness of the third fiber layer 22a, the stiffness of the tip section of the blade 100 may be increased, thereby avoiding excessive tip deflection and tower interference and reducing the risk of blade tower sweeping.

Second, for wind turbine blades, the web is mainly subjected to the shearing force of the blade, especially from 1/3 of the length to the tip, and is relatively thin and soft, and the web needs to meet the strength and rigidity requirements in a small space, so that the web of the tip section can meet the strength and rigidity requirements by making the fourth fiber layer 22b corresponding to the tip section of the blade 100 include carbon fibers, and the weight of the web, especially the web of the tip section, can be reduced.

Third, because the shell of the blade She Genduan is thicker, the stiffness and frequency will not greatly affect the web at She Genduan, according to embodiments of the present invention, the manufacturing cost of the web may be reduced by applying glass fibers to the web 20 corresponding to the root section of the blade 100, while the stiffness and strength requirements of the tip section may be met by applying carbon fibers to the web 20 corresponding to the tip section.

Fourth, by applying carbon fibers in the web 20 corresponding to the tip section of the blade 100, the natural frequency of the blade 100 may be increased by the high frequency characteristics of the carbon fibers themselves, avoiding resonance of the blade 100 with the tower.

According to an embodiment of the present invention, each of the reinforcements 22 may include a third fiber layer 22a and a fourth fiber layer 22b.

In addition, it should be understood that the specific stiffness of the third fibrous layer 22a and the specific stiffness of the fourth fibrous layer 22b refer to the average specific stiffness of the third fibrous layer 22a and the average specific stiffness of the fourth fibrous layer 22b. That is, when the third fiber layer 22a has a plurality of fiber layers and the fourth fiber layer 22b has a plurality of fiber layers, the specific stiffness of the third fiber layer 22a means an average value of the rigidities of the plurality of fiber layers of the third fiber layer 22a, and the specific stiffness of the fourth fiber layer 22b means an average value of the rigidities of the plurality of fiber layers of the fourth fiber layer 22b.

According to an embodiment of the present invention, the third fiber layer 22a may include only glass fibers, and the fourth fiber layer 22b may include only carbon fibers. By this arrangement, the stiffness of the web 20 in the tip region can be further increased, thus optimizing the effect of reducing the risk of blade tower scanning.

Alternatively, according to an embodiment of the present invention, the third fiber layer 22a may include only glass fibers, and the fourth fiber layer 22b may include both glass fibers and carbon fibers. By this arrangement, the manufacturing cost of the web can be reduced while preventing the blade from sweeping the tower.

Alternatively, according to an embodiment of the present invention, the third fiber layer 22a includes both glass fibers and carbon fibers, the fourth fiber layer 22b includes both glass fibers and carbon fibers, and the weight of carbon fibers per unit volume of the fourth fiber layer 22b is greater than the weight of carbon fibers per unit volume of the third fiber layer 22 a. That is, in the case where both the third fiber layer 22a and the fourth fiber layer 22b include glass fibers and carbon fibers, the arrangement density of the carbon fibers in the fourth fiber layer 22b is higher than that in the third fiber layer 22a so that the specific stiffness of the second fiber layer is higher than that of the first fiber layer. By this arrangement, the stiffness of the tip section of the web 20 can be further increased compared to the root section of the web 20, thereby avoiding a tower sweep accident.

According to an embodiment of the present invention, when the third fiber layer 22a includes both glass fibers and carbon fibers, the glass fibers and the carbon fibers are arranged in any one of the following ways: the glass fibers and the carbon fibers are arranged in a staggered manner in the thickness direction of the blade web, the glass fibers are arranged above the carbon fibers, and the glass fibers are arranged below the carbon fibers. Here, "above" and "below" are determined based on fig. 7, and "above" may refer to a direction away from the core 21, and "below" may refer to a direction close to the core 21.

In addition, according to the embodiment of the present invention, when the fourth fiber layer 22b includes both glass fibers and carbon fibers, the glass fibers and the carbon fibers are arranged in any one of the following ways: the glass fibers and the carbon fibers are arranged in a staggered manner in the thickness direction of the blade web, the glass fibers are arranged above the carbon fibers, and the glass fibers are arranged below the carbon fibers. "above" and "below" are to be understood in a similar manner to the above description.

When the blade 100 includes two webs 20, each web 20 of the two webs 20 may have the structure shown in fig. 6 and 7 according to an embodiment of the present invention.

According to an embodiment of the invention, the third fibrous layer 22a may be provided from the root of the web 20 up to 1/2-2/3 of the length of the web 20. The fourth fibrous layer 22b may be disposed from the tip of the web 20 to the region overlapping the third fibrous layer 22a to meet strength and stiffness requirements in a smaller space.

As shown in fig. 7, the third fiber layer 22a and the fourth fiber layer 22b are staggered and overlapped together to form an overlapped region, thereby connecting the third fiber layer 22a and the fourth fiber layer 22b as one body.

Since the web mainly bears the shear force of the blade according to the embodiment of the present invention, in order to secure the lap quality, the lap length of the third fiber layer 22a and the fourth fiber layer 22b (referred to as the lap length formed by the single layer of the third fiber layer 22a and the single layer of the fourth fiber layer 22 b) is between 5cm and 30 cm. If the overlap length is less than 5cm, the strength of the web 20 at the overlap is insufficient, and if the overlap length is greater than 30cm, the weight of the web 20 may increase.

According to an embodiment of the present invention, the third fiber layer 22a and the fourth fiber layer 22b may be overlapped in a stepped manner, similar to the first fiber layer 11 and the second fiber layer 12. By this arrangement, the web 20 is prevented from becoming too thick in the overlap region of the third and fourth

fibrous layers

22a, 22 b.

In addition, the web thickness in the overlap region may also be reduced by reducing the fiber density of the third and fourth fiber layers 22a and 22b in the overlap region. Specifically, the thickness of the fiber layers is related to the density of the fiber layers, and as the density of the fiber layers increases, the thickness of the web 20 in the overlap region of the third fiber layer 22a and the fourth fiber layer 22b is prevented from becoming excessively thick by reducing the fiber density of the third fiber layer 22a and the fourth fiber layer 22b in the overlap region, thereby reducing the thickness of the third fiber layer 22a and the fourth fiber layer 22b in the overlap region. Thus, according to embodiments of the present invention, the fiber density of the third fiber layer 22a in the overlap region may be made lower than the fiber density of the third fiber layer 22a in other regions, and the fiber density of the fourth fiber layer 22b in the overlap region may be made lower than the fiber density of the fourth fiber layer 22b in other regions.

It should be appreciated that while fig. 7 shows only three layers of third and fourth

fibrous layers

22a, 22b, fig. 7 is merely an example, and the particular number of layers of third and fourth

fibrous layers

22a, 22b of web 20 is not particularly limited and may be designed according to the overall structural design of blade 100.

According to an embodiment of the present invention, the reinforcement 22 may further include a resin coating the third and fourth fiber layers 22a and 22b to mold the third and fourth fiber layers 22a and 22 b. Accordingly, in fig. 6 and 7, the cured resin is provided between the adjacent fiber layers of the third fiber layer 22a and the fourth fiber layer 22 b.

As an example, the web 20 in fig. 6 and 7 may be manufactured by any one of the following ways: laying up a third fibre layer 22a and a fourth fibre layer 22b of a reinforcement 22 in the web mould; laying a core material 21; a third fiber layer 22a and a fourth fiber layer 22b of another reinforcing part 22 are laid on the core material 21; the web 20 is molded by pouring resin.

According to the web plate provided by the embodiment of the invention, four technical effects can be achieved at the same time: 1. the blade tip deflection is prevented from being too large to interfere with the tower, and the risk of sweeping the tower by the blade is reduced; 2. the web plate of the blade tip section meets the requirements of strength and rigidity, and simultaneously the weight of the web plate can be reduced; 3. the manufacturing cost of the web plate can be reduced; 4. avoiding resonance of the blade and the tower.

Blade root preform according to an embodiment of the invention

Hereinafter, a blade root preform according to an embodiment of the present invention will be described with reference to fig. 8 to 10.

Fig. 8 to 10 are schematic views of a blade root preform according to an embodiment of the invention.

As shown in fig. 8 to 10, the blade root preform 30 according to the embodiment of the present invention includes a bolt sleeve 31 arranged in a circumferential direction and a fiber layer covering the bolt sleeve 31, the fiber layer including glass fibers and carbon fibers.

Since the root of the blade is subjected to a large load, it is necessary to increase the strength of the root preform 30. However, if carbon fibers are used as the layering of the blade root preform 30 in its entirety, on the one hand the manufacturing costs are high and on the other hand the layering thickness of the blade root preform 30 is insufficient, increasing the risk of breakage.

According to the embodiment of the present invention, by making the fiber layer include both glass fibers and carbon fibers, the following technical effects can be achieved at the same time: meets the strength requirements of the root preform 30, reduces the risk of breakage of the root preform 30, and reduces manufacturing costs and weight.

According to an embodiment of the present invention, the fiber layers may include an inner fiber layer 32 disposed radially inward of the bolt housing 31 and an outer fiber layer 33 disposed radially outward of the bolt housing 31. The specific number of layers of the inner fiber layer 32 and the outer fiber layer 33 is not particularly limited, and may be determined according to structural design.

As an example, as shown in fig. 8, the inner fiber layer 32 is glass fiber, and the outer fiber layer 33 is carbon fiber. When the inner fiber layer 32 and the outer fiber layer 33 each have a plurality of layers, each of the inner fiber layer 32 is glass fiber and each of the outer fiber layer 33 is carbon fiber.

As another example, as shown in fig. 9, the inner fiber layer 32 is carbon fiber, and the outer fiber layer 33 is glass fiber. When the inner fiber layer 32 and the outer fiber layer 33 each have a plurality of layers, each of the inner fiber layer 32 is carbon fiber and each of the outer fiber layer 33 is glass fiber.

As another example, the inner fiber layer 32 and the outer fiber layer 33 each include glass fibers and carbon fibers (as shown in fig. 10). According to an embodiment of the present invention, although not shown, glass fibers and carbon fibers may be arranged in staggered layers in each of the inner fiber layer 32 and the outer fiber layer 33. "staggered arrangement" refers not only to the case where glass fibers and carbon fibers are alternately arranged one by one, but also to the case where glass fibers and carbon fibers are alternately arranged two (three or more) in two (three or more).

According to an embodiment of the present invention, as shown in fig. 8-10, the blade root preform 30 may further include a stop 34 and a bevel transition 35. According to an embodiment of the present invention, a blocking member 34 may be provided at one end of the bolt housing 31 to prevent resin from being poured into the bolt housing 31 when the resin is poured. As an example, the thickness (radial dimension) of the blocking member 34 may be equal to the radial dimension of the bolt housing 31 (dendrite of a single bolt housing 31).

The bevel transition 35 may be disposed outside of the stop 34, with one end of the bevel transition 35 in contact with the stop 34 and the other end of the bevel transition 35 extending away from the bolt housing 31. The thickness of the angled transition 35 decreases gradually from one end of the angled transition 35 to the other end of the angled transition 35. By providing the angled transition piece 35, the thickness of the root preform 30 may be smoothly transitioned in accordance with embodiments of the present invention.

As an example, the blade root preform 30 may be manufactured by: an outer fibre layer 33 is laid, a bolt sleeve 31, a stop 34 and a bevel transition piece 35 are laid, then an inner fibre layer 32 is laid, and finally resin is poured to shape the blade root preform 30.

The above description is of a pre-buried bolt bushing type blade root preform 30, which may also be a perforated type blade root preform according to an embodiment of the present invention. Compared with the pre-buried bolt sleeve type blade root prefabricated member 30, the punching type blade root prefabricated member does not need a pre-buried bolt sleeve, but is provided with a bolt hole which is annularly arranged by punching on one side of the blade root prefabricated member after a fiber layer is paved and resin is poured.

According to the blade root prefabricated part provided by the embodiment of the invention, the blade root strength of the blade can be improved, and the fracture risk, the manufacturing cost and the weight of the blade root prefabricated part are reduced.

Blade according to an embodiment of the invention

Hereinafter, a blade according to an embodiment of the present invention will be described with reference to fig. 11 and 1.

As shown in fig. 1 and 11, a blade 100 according to an embodiment of the invention may include at least one of a spar 10, a web 20, and a root preform 30 as described above.

Preferably, the blade 100 according to an embodiment of the present invention may comprise three of the spar 10, the web 20 and the root preform 30 as described above. The white area of the girder 10 in fig. 11 indicates that the fiber layer of the girder 10 is glass fiber, and the gray area of the girder 10 indicates that the fiber layer of the girder 10 is carbon fiber.

In addition, the blade 100 according to an embodiment of the present invention may further include a spar under-blanket (not shown) provided on the inner side (side near the outside of the blade) of each of the two spars 10 and a spar over-blanket (not shown) provided on the outer side (side near the inside of the blade) of each of the two spars 10.

Each of the spar lower and upper spar plies includes carbon and glass fibers disposed sequentially from the root of the blade 100 in the spanwise direction of the blade 100.

According to the embodiment of the present invention, in each of the girder lower and upper decks, by providing carbon fibers at the blade root section of the blade 100 and providing glass fibers at the blade tip section of the blade 100, the structural strength of the blade root section with concentrated loads can be improved, and the weight and manufacturing cost of the entire blade 100 can be reduced.

In each of the spar lower and spar upper plies, carbon fibers are disposed from the root of the blade 100 to 1/4-1/3 of the length of the blade 100, with glass fibers overlapping the carbon fibers and being disposed to the tip of the blade in the spanwise direction of the blade 100, in accordance with an embodiment of the present invention.

In accordance with an embodiment of the present invention, the carbon and glass fibers in the spar lower and upper plies may also overlap in a step-wise fashion in the spanwise direction of the blade 100, similar to the manner in which the fiber layers of the spar 10 of FIG. 4 overlap.

As an example, the blade 100 may be manufactured by the method described below.

The blade root prefabricated member 30 is placed in a blade shell mould, and then the main girder lower layer, the core material, the main girder 10 and the main girder upper layer are paved, and after the paving is completed, a vacuum pouring process is used for pouring and curing to prepare the pressure surface shell 101 and the suction surface shell 102. When the blade is paved, before solidification, a layer of lightning protection metal net is added below the carbon fiber section main beam of the main beam 10 (the outer surface of the main beam 10) to be connected to the blade lightning arrester for lightning protection, so that the blade is prevented from being damaged by lightning stroke when using carbon fibers.

After the pressure side shell 101 and the suction side shell 102 are prepared, the two half shells of the pressure side shell 101 and the suction side shell 102 need to be adhered together by structural adhesive to form a blade. Before this, the web 20 is adhered to the region of either the pressure side shell 101 or the suction side shell 102 (for example, the pressure side shell 101 in fig. 1) corresponding to the main beam 10, and after the web 20 is adhered and cured, the other half shell is adhered together by structural adhesive by turning the mold of the other of the pressure side shell 101 and the suction side shell 102. After the blades are bonded together, a blade with a firm structure is required to be formed through a curing process.

According to the blade provided by the embodiment of the invention, the technical effects of four aspects can be achieved simultaneously: 1. the blade tip deflection is prevented from being too large to interfere with the tower, and the risk of sweeping the tower by the blade is reduced; 2. the blade tip section meets the requirements of strength and rigidity, and simultaneously, the weight of the blade, especially the weight of the blade tip, can be reduced; 3. the manufacturing cost of the blade can be reduced; 4. avoiding resonance of the blade and the tower.

While exemplary embodiments of the present invention have been particularly described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

Claims

1. A main girder of a blade is characterized in that the main girder (10) comprises a first fiber layer (11) and a second fiber layer (12), the first fiber layer (11) and the second fiber layer (12) are sequentially arranged along the length direction of the main girder (10) from the root of the main girder (10) towards the tip of the main girder (10),

the first fiber layer (11) extending from the root of the girder (10) towards the tip of the girder (10) and being spaced apart from the tip of the girder (10), the second fiber layer (12) extending from the tip of the girder (10) towards the root of the girder (10) and being spaced apart from the root of the girder (10), the first fiber layer (11) comprising glass fibers, the second fiber layer (12) comprising carbon fibers, the specific stiffness of the second fiber layer (12) being greater than the specific stiffness of the first fiber layer (11),

Wherein the first fiber layer (11) and the second fiber layer (12) are arranged in a staggered manner and are lapped together to form a lapping area, and the lapping length of the first fiber layer (11) and the second fiber layer (12) is between 10cm and 50 cm.

2. The girder according to claim 1, characterized in that the first fibre layer (11) and the second fibre layer (12) are step-wise overlapping.

3. The girder according to claim 1, characterized in that the first fibre layer (11) has a lower fibre density in the overlap region than in other regions of the first fibre layer (11), and the second fibre layer (12) has a lower fibre density in the overlap region than in other regions of the second fibre layer (12).

4. The girder according to claim 1, characterized in that the first fibre layer (11) comprises only glass fibres and the second fibre layer (12) comprises only carbon fibres.

5. The girder according to claim 1, characterized in that the first fibre layer (11) comprises only glass fibres and the second fibre layer (12) comprises both glass fibres and carbon fibres.

6. The girder according to claim 1, characterized in that the first fiber layer (11) comprises both glass fibers and carbon fibers, the second fiber layer (12) comprises both glass fibers and carbon fibers, the weight of carbon fibers per volume of the second fiber layer (12) being greater than the weight of carbon fibers per volume of the first fiber layer (11).

7. The girder according to claim 6, characterized in that in the first fibre layer (11) glass fibres and carbon fibres are arranged in any one of the following ways: the glass fibers and the carbon fibers are arranged in a staggered manner in the thickness direction of the main beam, the glass fibers are arranged above the carbon fibers, and the glass fibers are arranged below the carbon fibers.

8. The girder according to claim 5 or 6, characterized in that in the second fibre layer (12) glass fibres and carbon fibres are arranged in any one of the following ways: the glass fibers and the carbon fibers are arranged in a staggered manner in the thickness direction of the main beam, the glass fibers are arranged above the carbon fibers, and the glass fibers are arranged below the carbon fibers.

9. The girder according to claim 1, characterized in that the girder (10) comprises a first girder section (10 a) and a second girder section (10 b) connected to each other, the first girder section (10 a) comprising the first fibre layer (11) and the second girder section (10 b) comprising the second fibre layer (12).

10. The girder according to claim 9, characterized in that the first girder segment (10 a) and the second girder segment (10 b) are adhered to each other by means of an adhesive layer (10 c), and that the bonding surface of the first girder segment (10 a) and the second girder segment (10 b) is an inclined surface.

11. The girder according to claim 10, characterized in that the two sides of the bonding area of the first girder segment (10 a) and the second girder segment (10 b) are provided with a stiffening layer (10 d).

12. The girder according to claim 1, characterized in that the second fibre layer (12) is arranged from the tip of the girder (10) to more than 1/3 of the length of the girder (10).

13. A blade, characterized in that the blade (100) comprises a spar (10) according to any of claims 1-12.

14. The blade according to claim 13, wherein the blade (100) further comprises a blade root preform (30), the blade root preform (30) comprising a fiber layer comprising glass fibers and carbon fibers.

15. Blade according to claim 14, wherein the blade root preform (30) comprises a bolt sleeve (31) arranged in a circumferential direction, the fibre layers comprising an inner fibre layer (32) arranged radially inwards of the bolt sleeve (31) and an outer fibre layer (33) arranged radially outwards of the bolt sleeve (31),

the inner fiber layer (32) is glass fiber, the outer fiber layer (33) is carbon fiber, or the inner fiber layer (32) is carbon fiber, the outer fiber layer (33) is glass fiber, or

The inner fiber layer (32) and the outer fiber layer (33) each comprise glass fibers and carbon fibers.

16. Blade according to claim 15, wherein in each of the inner fibre layer (32) and the outer fibre layer (33) glass fibres and carbon fibres are arranged in staggered layers.

17. The blade according to claim 13, wherein the blade (100) further comprises a girder lower layer arranged on the outside of the girder (10) and a girder upper layer arranged on the inside of the girder (10), each of the girder lower layer and the girder upper layer comprising carbon fibers and glass fibers arranged in sequence from the blade root of the blade (100) towards the blade tip of the blade (100), the carbon fibers being arranged from the blade root of the blade (100) to 1/4-1/3 of the length of the blade (100).

18. The blade of claim 17, wherein the carbon fibers and the glass fibers are step lap jointed in each of the spar under ply and the spar over ply.

19. The blade according to claim 13, characterized in that the blade (100) comprises two girders (10), one (10) of the two girders (10) being a girder according to claim 4, the fibre layer of the other (10) of the two girders (10) comprising only glass fibres.

20. A blade according to any one of claims 13 to 19, characterized in that the blade (100) further comprises a web (20), the web (20) comprising a core (21) and reinforcing parts (22) arranged on both sides of the core (21), respectively,

at least one of the reinforcing parts (22) comprises a third fiber layer (22 a) and a fourth fiber layer (22 b), the third fiber layer (22 a) and the fourth fiber layer (22 b) are sequentially arranged from the root of the web (20) towards the tip of the web (20), the third fiber layer (22 a) comprises glass fibers, the fourth fiber layer (22 b) comprises carbon fibers, and the specific stiffness of the fourth fiber layer (22 b) is greater than that of the third fiber layer (22 a).