WO2017076096A1

WO2017076096A1 - Reinforced blade for wind-driven generator

Info

Publication number: WO2017076096A1
Application number: PCT/CN2016/094594
Authority: WO
Inventors: 周方
Original assignee: 周方
Priority date: 2015-11-03
Filing date: 2016-08-11
Publication date: 2017-05-11
Also published as: CN105298741B; CN105298741A

Abstract

A reinforced blade assembly (1) comprises: a blade (100); connection supports (11, 12, 13) fixed to the blade (100), extending in the longitudinal direction along the blade and striding by a certain span; and at least one thin and long blade reinforcing member (21, 22, 23, 24, 25, 26). The blade reinforcing members (21, 22, 23, 24, 25, 26) are configured in a manner in which at least one end of the ends of the blade reinforcing members (21, 22, 23, 24, 25, 26) is connected to the connection supports (11, 12, 13) so as to be separated from the blade (100). The blade assembly can improve the rigidity and the strength of a large blade, can reduce the weight of the blade, and can reduce cost of the blade.

Description

Reinforced blades for wind turbines

Technical field

The invention relates to a reinforced blade preferably used for a wind power installation, in particular for a horizontal axis wind turbine, and a method of manufacturing the blade. The invention also relates to a rotor having the blade, and a wind power installation, a wind power generation apparatus, a marine current power generation apparatus or a power flow generation apparatus having the rotor.

Background technique

Wind energy is a clean renewable energy source that has grown rapidly in recent years. It is important that clean renewable energy compete with conventional energy sources (coal, oil, natural gas, and large and medium-sized hydropower) to reduce costs and increase operational efficiency. At present, wind power generation in the world is further developing in the direction of high power and long blades. Large horizontal axis wind turbines are more cost effective in manufacturing, installation and operation. The unit cost of wind power generation decreases as the unit power of wind power generation increases.

The blade transfer torque produces energy. Although not limited by theory, it is believed that the electrical energy generated by the horizontal-axis wind turbine is proportional to the square of the length of the blade, and the increase in the weight of the blade material is proportional to the cube length of the blade, increasing as the length of the blade increases. The aerodynamic load of the blade and the weight of the blade material also increase greatly. Moreover, large wind turbine blades must have higher flexural strength due to increased blade loading. This increases the thickness of the blade material and correspondingly increases the weight of the blade material.

For large blades, stiffness also becomes a major problem. In order to ensure that the tip of the blade does not bend to the extent of touching the tower under extreme wind loads, the blade must have sufficient bending stiffness, which in turn increases the weight of the blade.

The weight of the blade material has an important influence on the operation of the wind turbine, fatigue life and energy output.

In addition, large-scale blades are produced in full size and are difficult to transport, and are increasingly becoming a bottleneck restricting the development of wind power. For longer-sized fan blades that are likely to be larger in the future, long-distance transport of full-size blades will be more difficult.

In addition, in modern wind turbine blade designs, the blade shape also requires a balance of aerodynamic efficiency and structural rationality to achieve maximum performance at the lowest possible cost.

Without wishing to be acknowledged by the prior art, FIG. 1 shows a schematic cross-sectional view of an exemplary blade. As shown in Fig. 1, the blade 1' of the wind turbine may include a blade casing 2 and a beam structure 3 located within the blade casing 2. In the example shown in FIG. 1, the beam structure 3 is, for example, a rectangular beam knot. The structure comprises a main beam 4 fixed on the inner side of the leaf shell and an anti-shear web 5 which is connected at both ends of the two main beams 4. The aerodynamically formed blade shell is wrapped around the main beam. The main bending load is borne by the main beam, which only bears a small amount of bending load. The beam structure of the blade, especially the weight of the main beam, also accounts for the main part of the blade.

A common leaf material is fiberglass composite (GFRP). For example, both the blade main beam and the blade shell can be made of a fiberglass composite. For large blades made of fiberglass composites, the strength and rigidity of the blades are to be met. The main girder of the blade is designed to be very thick and the blades are very heavy. When the wind turbine is running, the blade gravity generates an alternating load, which causes the blade itself and the unit to generate fatigue stress. The increase of the weight of the blade causes the blade to reach the fatigue strength prematurely. This requires increasing the strength of the blade and increasing the weight of the blade, and correspondingly increasing the weight of the wind turbine's hub, nacelle, tower, etc., which ultimately leads to a substantial increase in the cost of the entire wind turbine, correspondingly increasing the unit cost of wind power generation. .

In order to reduce the weight of the blade and meet the strength and stiffness requirements, the current technical method is to use carbon fiber composite (CFRP) instead of glass fiber composite to manufacture the blade main beam, but the carbon fiber composite material is very expensive.

Therefore, improving the strength and rigidity of large blades, while reducing the weight of the blades and reducing the cost of the blades, is an urgent problem to be solved in the current development of wind power.

The prior art proposes to strengthen the rotor of a wind power generator.

Chinese Patent Application Publication No. CN101230834A relates to a tension wind turbine wind wheel, the blade is divided into two stages, and a middle shaft seat is arranged in the middle, and a composite material strip with a streamlined cross section is drawn between the three middle shaft seats to form an equilateral triangle, so that each When the blades are at different potentials in the gravitational acceleration, the unbalanced external forces are offset; the three central axle seats and the front and rear ends of the hub also use similar tensile forces to strengthen the wind wheels.

US Patent Application Publication No. US 2010/0086407 A1 relates to a wind turbine rotor comprising one or more rotor blades and rotor reinforcement elements for reinforcing the rotor, wherein the rotor blades are arranged such that they are capable of being relative about their longitudinal axis Rotating the corresponding rotor reinforcement element. Each rotor blade may include at least two rotor blade portions, wherein the outer rotor blade portion is arranged to be rotatable relative to the inner rotor blade portion. The wind turbine rotor also includes attachment means for connecting the rotor reinforcement elements to one another. The wind turbine rotor also includes a blade stiffening element and a spacer element for reinforcing the rotor blade to prevent bending deflection.

The above-described prior art wind wheel or rotor has a complicated structure, and it is necessary to install a tension wire between adjacent blades to balance the blade gravity. When the wind turbine is in operation, the blades vibrate in the flapping direction (perpendicular to the rotor blade rotation plane) and the shimmy direction (in the rotor blade rotation plane). Due to tension The presence of the line, the dynamic response of the blade is more complicated. The vibration of each blade is not completely synchronized, so the blades interact with each other, and the amplitude of the blade in the direction of the shimmy is also likely to increase, and the maximum bending moment in the direction of the shimmy is also likely to increase.

In addition, due to the central axis seat between the two leaf segments (the '834 publication) and the connecting device and the spacer element (the '407 publication), the connection between the leaf segments is not robust and affects the aerodynamics of the blade. Efficiency and structural rationality, and these joint structures are complex and may result in loss of strength of the blade at the joint. In particular, in the '407 publication, since the spacer elements for the blade reinforcing elements are only mounted at the longitudinal point positions between adjacent two blade segments, the arrangement of the blade reinforcing members may result in the creation of the blade segment connection portions. Large bending moments result in loss of bending stiffness.

Accordingly, it is desirable to provide an improved reinforced blade that is structurally simpler that can have higher strength and stiffness, and that is preferably effective to reduce blade weight.

Summary of the invention

Accordingly, it is an object of the present invention to provide a reinforced blade that has a lighter weight while meeting the strength and stiffness requirements of the blade.

In accordance with an embodiment of the present invention, a reinforced blade assembly is provided, comprising: a blade, a connecting bracket secured to the blade and extending longitudinally across the span of the blade and at least one elongated blade stiffener, wherein The blade reinforcement is configured to be coupled to the attachment bracket at least one end to be spaced apart from the blade.

By the combination of the blade reinforcement and the connecting bracket, it is possible to provide a blade with a required light weight and stiffness, in particular a higher bending stiffness, with a relatively light weight. In particular, the connecting bracket extending in the longitudinal direction across a distance can effectively ensure the rigidity at the joint position of the blade reinforcement.

Preferably, the blade reinforcement is a tensile reinforcement and is configured to be tension pre-stressed.

More preferably, the blade reinforcement is a high strength, high modulus fiber rope, such as a carbon fiber rope or the like. This provides a surprising weight loss effect and high strength of the blade.

According to a preferred embodiment, at least one of the blade reinforcements is configured to be coupled to the connecting bracket at one end of the blade stiffener and directly to the blade at the other end of the blade stiffener.

According to a preferred embodiment, at least one of the blade reinforcements is configured to be in the Both ends of the blade reinforcement are coupled to respective connecting brackets and extend generally parallel to the blades.

According to a preferred embodiment, the reinforced blade assembly includes a plurality of said blade reinforcements. According to a further preferred embodiment, at least two of the plurality of blade stiffeners are configured to extend longitudinally along the blade in substantially longitudinal alignment and to connect to both sides of the same connecting bracket. Additionally or alternatively, at least two of the plurality of blade stiffeners are configured to extend longitudinally along the blade in parallel and to the same side of the same connecting bracket.

According to a preferred embodiment, the connecting bracket comprises a first leg, a second leg spaced apart from the first leg in the longitudinal direction of the blade, and the first leg and the second leg are fixedly connected or integrated with each other Formed connecting element. This advantageously enhances the stiffness of the blade, especially at the connection bracket.

According to a preferred embodiment of the invention, the blade comprises a plurality of blade segments, the connecting bracket comprising a first leg on one of the blade segments, a second leg on an adjacent blade segment, and the A connecting member in which the first leg and the second leg are fixedly connected to each other. Thereby, the connecting bracket not only provides increased rigidity, but also strengthens the fixed connection between adjacent leaf segments.

According to a specific embodiment, the blade comprises a beam structure and a blade shell encasing the beam structure.

According to another aspect of the present invention, there is provided a rotor for a wind power installation comprising a hub and a plurality of blades coupled to the hub, wherein at least one of the plurality of blades is a reinforced blade according to the present invention Component.

According to another aspect of the invention, a wind power installation is provided which is a wind power plant and includes a rotor according to the invention.

According to another aspect of the present invention, a method of manufacturing a reinforced blade assembly is provided, comprising the steps of:

Providing a plurality of leaf segments, wherein each leaf segment is fixedly connected or integrally formed with a connecting leg;

Fixing the leaf fragments to each other;

Connecting the connecting legs of adjacent blade segments to each other by means of connecting elements to form a connecting bracket extending longitudinally across the span of the blade;

An elongated blade stiffener is mounted in the blade assembly, wherein at least one end of the blade stiffener is fixedly coupled to the connecting leg.

Other features and advantages of the invention will be apparent to those skilled in the art from this disclosure.

DRAWINGS

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which:

Figure 1 is a schematic cross-sectional view of an exemplary blade;

2 is a perspective view of a reinforced blade according to an embodiment of the present invention;

3A is a front elevational view of a reinforced blade in accordance with an embodiment of the present invention;

3B is a side view of a reinforced blade in accordance with an embodiment of the present invention;

Figure 4 is a partial enlarged view of a reinforced blade according to an embodiment of the present invention, showing the connection of the blade reinforcement and the connecting bracket;

Figure 5 is a partial enlarged view of a reinforced blade according to an embodiment of the present invention, showing details of the connection bracket;

6A and 6B are schematic cross-sectional views showing a blade beam structure of a comparative example and a reinforced blade beam structure according to an embodiment of the present invention, respectively.

detailed description

For a better understanding of the technical features, objects and effects of the present invention, the embodiments of the present invention will be described with reference to the accompanying drawings. The drawings are provided to present some embodiments of the present invention, but the drawings are not necessarily drawn to the dimensions of the specific embodiments, and some features may be enlarged, removed, or cut to better illustrate and explain the disclosure of the present invention. content. The appearances of the phrase "in the drawings"

Certain directional terms used in the description to describe the figures, such as "upper", "lower", "left", "right", "upward", "downward" and other directional terms, will be understood This is not to be interpreted as a limitation of the scope of the appended claims.

The term "about" or "approximately" in the present invention will be understood by those of ordinary skill in the art and will vary within a certain scope depending on the context in which the term is used.

An embodiment of a reinforced blade assembly for a wind power plant rotor in accordance with the present invention will now be described with reference to the accompanying drawings. According to an embodiment of the invention, the reinforced blade assembly is for a wind power plant, such as a horizontal axis wind turbine, preferably a large horizontal axis wind turbine. However, it is contemplated that the reinforced blade assembly in accordance with the present invention can also be used in any suitable application using blades, such as other types of wind equipment, ocean currents, and tidal power plants.

Although not shown, exemplary wind power plants include, for example, fans and generators. The fan may include a rotor having a hub and a plurality of blades, preferably the plurality of blades are evenly circumferentially about the hub Arranged at intervals. Preferably, the blade according to the invention can be rotated longitudinally about the blade, for example the blade is of variable pitch. As is known and not shown, the fan may further comprise a nacelle for rotatably supporting the rotor and a tower supporting the nacelle. Preferably, the nacelle rotatably supports a hub or shaft (not shown) of the rotor such that rotation of the rotor can drive wind power, for example by means of a transmission mechanism housed in the nacelle. In the present invention, the configuration of the nacelle and the tower is not critical and therefore will not be described again. Furthermore, the blade assembly and rotor according to the invention can also be applied correspondingly to other configurations of wind power plants, such as those without a nacelle and/or a tower.

The reinforced blade assembly 1 according to an embodiment of the present invention may include a blade 100 and a blade reinforcement. Preferably, the blade stiffening device can comprise an elongated blade stiffener and a connecting structure, such as a connecting bracket, as described in more detail below.

The blade 100 according to an embodiment of the present invention may be constructed, for example, as in Fig. 1, including a blade outer casing 2 and a beam structure 3 covered by the blade outer casing 2. As previously mentioned, in the illustrated embodiment, the beam structure 3 can include a pair of main beams 4 and shear resistant webs 5. As previously mentioned, the blades, such as the blade shell 2 and the beam structure 3, in the illustrated embodiment may be made of a fiberglass composite. Those skilled in the art will appreciate that blades in accordance with embodiments of the present invention may utilize different blade configurations, materials, and shapes. For example, different beam structures, blade airfoil profiles can be used. For example, the blade shell and beam structure are made of different materials, or the material of the blade shell is different from the material of the beam structure.

2 to 5 show a reinforced blade assembly 1 of an embodiment of the present invention. The blade 100 may comprise a plurality of leaf segments, in the illustrated embodiment, comprising three leaf segments, ie a first leaf segment or a blade root segment 101, a second leaf segment or an intermediate leaf segment 102, a third leaf Fragment or leaf tip segment 103. Those skilled in the art will appreciate that the blade 100 can include more or less than three segments of the blade segment, which falls within the scope of the invention. It will also be apparent to those skilled in the art that the blade according to the present invention may be single piece, i.e., without a plurality of blade segments, which is also within the scope of the invention.

A segmented blade according to an embodiment of the invention may have a joint surface (not shown) for engaging adjacent blades. The blade segments can be joined at the joint faces of the blade segments by any suitable means, such as preferably welding, riveting or material fusion, to form the integral blade.

With continued reference to Figures 2 through 5, an illustrative embodiment of a blade stiffening device in accordance with the present invention is specifically described below.

As previously mentioned, the blade stiffening means may comprise an elongated blade stiffener 21 mounted on the outside of the blade shell 2, in particular on the windward side of the blade (the direction of the arrow in W in Fig. 3B is the direction of the wind), 22, 23, 24, 25, 26 and the connection structure are here in the form of connecting

brackets

11, 12, 13. The connecting structure, such as the connecting bracket, is preferably directly fixed or integrally formed to the blade shell and/or the main beam.

As shown in Fig. 2, in the illustrated embodiment, the blade assembly 1, and in particular the blade reinforcement, can include three

attachment brackets

11, 12, 13 that are secured to the blade 100 and that extend longitudinally across the blade over a span. In the illustrated embodiment, the plurality of attachment brackets are preferably arranged along a generally longitudinal direction of the blade. However, it is contemplated that the blade assembly can include more or fewer attachment brackets, and the number of attachment brackets can preferably be equal to the number of blade segments, but can also be unequal. The attachment bracket can have a variety of shapes and/or configurations, and a specific embodiment of the attachment bracket will be detailed below.

3A and 3B show front and side views, respectively, of the reinforced blade assembly of the present invention. The blade assembly 1, in particular the blade reinforcement, may comprise a plurality of elongated blade reinforcements, in the illustrated embodiment, six

blade reinforcements

21, 22, 23, 24, 25, 26. These blade stiffeners 21-26 are preferably connected to the connecting

brackets

11, 12, 13 at at least one end.

Preferably, the

blade reinforcements

21, 23, 25 and 22, 24, 26 are indirectly fixedly connected to the blade 100 or the blade shell and/or the main beam, either directly or by means of a connecting bracket, and by means of the connecting

brackets

11, 12, 13 The blade shells are spaced apart.

In the illustrated embodiment, the

blade stiffeners

21, 22 are connected to the connecting bracket 11 and the connecting bracket 12 at both ends in parallel along the longitudinal direction of the blade, and preferably extend substantially parallel to the blade surface. The

blade reinforcements

23, 24 are respectively connected in parallel to the longitudinal direction of the blade at both ends to the connection bracket 12 (the side opposite to the position at which the

blade reinforcements

21, 22 are coupled) and the connection bracket 13, and preferably extend substantially parallel to the blade surface. The

blade reinforcements

25, 26 are connected in parallel along the longitudinal direction of the blade at one end to the bracket 13 (the side opposite the connection position of the blade reinforcements 23, 24) and at the other end directly to the blade 100 or the blade at the connection points 14, 15 Fragment 103. Preferably, the appropriate position of the connection points 14, 15 is calculated from the load of the blade. In one non-limiting preferred embodiment, the other end can be coupled to the blade at the center of gravity of the blade segment 103. The connection point is equivalent to providing a fulcrum to the blade segment 103. This reduces the bending moment of the blade at the

joints

14, 15 of the blade segment 103 to the blade at the attachment means 13, thereby reducing the thickness of the main beam and the outer casing of the blade. In the illustrated embodiment, the

blade stiffeners

21, 23, 25 extend longitudinally in the longitudinal direction of the blade. In the illustrated embodiment, the

blade stiffeners

22, 24, 26 extend longitudinally in a longitudinal direction generally along the blade.

Referring to Figures 3A-B and Figure 4, a blade incorporating a connecting bracket and a blade stiffener connection is shown. In order to maintain the optimum geometric angle of attack of the blade, the blade has different leaves at different radial lengths. Piece twisted. The blade reinforcement and the attachment bracket according to an embodiment of the present invention are correspondingly arranged according to blades having different blade twist angles. Preferably, the plurality of blade stiffeners that are generally aligned in the longitudinal direction may extend along or be parallel to the pitch pitch axis of rotation or the aerodynamic center axis. In the illustrated embodiment, the first set of

blade stiffeners

21, 23 and 25 that are generally aligned in the longitudinal direction and the second set of

blade stiffeners

22, 24 and 26 that are generally aligned in the longitudinal direction may be associated with a pitch rotation axis or air The power center axes are located parallel to both sides of the axis, preferably symmetric about the axis. Although in the illustrated embodiment, it is shown that every three blade stiffeners are substantially longitudinally aligned, and that each two blade stiffeners are disposed in parallel on either side of the axis, other configurations are contemplated, such as more or fewer A longitudinally substantially aligned blade reinforcement, or a greater number of parallel blade reinforcements, or only longitudinally aligned blade reinforcements, or only parallel blade reinforcements, or in one embodiment, may have only one, for example A blade reinforcement extending along the axis and a connecting bracket, for example at the blade root or tip.

By means of the blade reinforcement according to the invention, the

blade reinforcements

21, 23 and 22, 24 and the connecting bracket enlarge the cross section of the blade main beam, increasing the bending stiffness (EI) of the blade. The bending stiffness (EI) of the blade waving direction is facilitated by means of a blade reinforcement extending in the longitudinal direction, in particular parallel to the pitch rotation axis or the aerodynamic center axis. More preferably, the blade stiffeners disposed on either side of the axis help to simultaneously increase the bending stiffness (EI) of the blade flapping direction and the shimmy direction.

Preferably, the blade reinforcement may have a preferred configuration, material and shape.

In a preferred embodiment, the blade reinforcements may have different cross-sectional shapes, such as a preferred circular shape, but may also be rectangular, square, elliptical, or the like. More preferably, the blade reinforcements may have different cross-sectional dimensions on each blade segment along the longitudinal direction of the blade. The cross-sectional dimension of the blade stiffener decreases from the blade root section to the blade tip section, and the distance between the blade stiffener and the blade shell can also be adjusted accordingly.

In a preferred but not shown embodiment, an outer cladding structure may be provided on the exterior of at least one, and preferably all, of the blade reinforcement. Preferably, the outer cross section of the blade reinforcement may also have a different shape, which may be circular, elliptical or the like. More preferably, the outer cross-section of the blade reinforcement is selected to conform to the aerodynamic outer shape to reduce windage and noise. It is particularly preferred to select the shape of the outer airfoil to generate lift which contributes to the rotation of the rotor blade.

In a preferred embodiment, at least one, preferably all, of the blade reinforcements are tensile reinforcements, preferably high strength tensile reinforcements, preferably flexible tensile reinforcements, preferably cords. Preferably, at least one, preferably all, of the blade reinforcement is a fiber reinforced composite The finished rope is more preferably a carbon fiber rope. However, it is contemplated that the blade stiffener may comprise or be another type of cord, such as a fiberglass cord made of the same material as the blade.

In a preferred embodiment, tension pre-stressing can be applied to the blade stiffeners 21-26 such that the blade main beams are first subjected to tensile stresses. During the operation of the blade, the pre-tensioning stress can partially offset the compressive stress caused by the load, thereby improving the bearing capacity of the blade.

Referring to Figure 5, an embodiment of a connecting bracket in accordance with the present invention is described. The

connection brackets

11, 12, 13 may include a first leg 31, a second leg 32 longitudinally spaced from the first leg 31, and a connecting rod 33 or any of the connecting pins 33 that securely connect the first leg 31 and the second leg 32 to each other Suitable connecting elements. With continued reference to FIG. 5, the attachment bracket can be frame-shaped, and preferably the first leg 31 and the second leg 32 can each be of a beam configuration, such as including preferably parallel column members 311-312, 321-322, and beam members, respectively. 313, 323. In the preferred embodiment shown, the overall frame-like configuration of the attachment bracket and the shape of the connecting element facilitates reducing the aerodynamic effects on the blade, such as minimizing windage. However, those skilled in the art will appreciate that the attachment brackets can take on other configurations or shapes, which are within the scope of the present invention. For example, the number or shape of the legs, the pillar members, the beam members, and/or the connecting members may vary.

With continued reference to FIG. 5, a method of fabricating a segmented reinforced blade in accordance with an embodiment of the present invention will be described. In an exemplary embodiment of the invention, the

blade segments

101, 102, and 103 are segmented and assembled on site. In the manufacture of the leaf segments, the individual leaf segments are fixedly joined or integrally formed with legs. For example, the first leg 31 is fixedly coupled or integrally formed to the blade segment 101 or its surface, and the second leg 32 is fixedly coupled or integrally formed to the adjacent blade segment 102 or its surface. When the blades are assembled on site, the

blade segments

101, 102 and 103, in particular their main beams, webs and shells, can be joined to each other using various suitable joining means, such as riveting and welding. The first and second legs can then be fixedly coupled using a connecting member, such as a connecting rod 33, to form a connecting bracket that extends longitudinally across the span of the blade over a span. In the embodiment shown, the adjacent blade segments are non-rotatably fixedly coupled between each other, thus ensuring the overall rigidity of the blade during operation. In this configuration, the connecting bracket not only provides improved bending stiffness like a beam because it spans a span in the longitudinal direction (and/or in the lateral direction), but also serves to improve the connection of adjacent blade segments.

Preferably, the blade stiffeners 21-26 can be attached to the attachment bracket (legs) and/or the blades (leaf segments) when manufacturing the blade segments. In an alternate embodiment, the blade stiffeners 21-26 can be installed in the field, such as after forming the connecting bracket.

However, those skilled in the art will appreciate that the connecting bracket may be integrally formed integrally with the blade or the blade main beam, the web and the outer casing, or the connecting bracket may be integrally fixedly coupled to the blade. Or the blade main beam, the beam web and the outer casing, which is especially suitable for integral blades. At this point, the connecting bracket can still provide improved bending stiffness like a beam because it spans a span in the longitudinal direction (and/or in the lateral direction).

Preferably, the connecting bracket may be formed from the same material as the blade or the blade main beam, the web and the outer casing, for example from a fiberglass composite, more preferably integrally formed by material fusion. However, those skilled in the art will appreciate that the attachment brackets can also be formed from different materials.

In order to specifically show the advantageous effects of the present invention, reference will be made hereinafter to FIGS. 6A and 6B for a comparative comparative example (FIG. 6A) and an embodiment according to the present invention (FIG. 6B).

The beam 1 of Fig. 6A shows a schematic sectional view of the blade beam structure of the comparative example. The upper and lower beam plates of the main beam have a thickness of t, a width of b, and a height of d. The material is a glass fiber composite material and the modulus of elasticity is E. The upper and lower beams of the main beam are fixed by shear webs. The main bending load is carried by the main beam, and the weight of the main beam of the blade accounts for the main part of the weight of the blade.

The beam 2 in Fig. 6B shows a schematic cross-sectional view of a beam structure of a reinforced blade according to an embodiment of the present invention. The upper and middle beams of the main beam have a thickness T and a width b. The upper and middle beams are fixed by shear webs, and the material is made of glass fiber composite material, and the elastic modulus is E. The blade reinforcement acts as the lower beam of the main beam, the elastic modulus is E _c , the cross-sectional area is S, and the equivalent elastic modulus area is the same as the upper beam (SE _c = TbE). The height of the beam structure is d+D.

Due to the flattening characteristics of the blade airfoil, the stiffness of the blade in the wiping direction is much smaller than the stiffness in the direction of the shimmy. The force in the direction of the swing is significantly greater than the force in the direction of the swing. The load in the direction of the shimmy is mainly affected by the gravity of the blade, and the load changes periodically. The bending stiffness, bending stress, maximum bending deformation of the free end and the weight of the beam are calculated below.

For comparison, set the beam 2 in Fig. 6B, D = d, T = t/2. Calculated according to the rectangular beam structure, it is assumed that the height d of the beam is much larger than the thickness of the beam plate (t, T) and the web, and the bending stiffness (EI) of the blade waving direction (for the x-axis or the x'-axis, the blade reinforcement is pulled The stress and the compressive stress of the upper beam are approximately equal to:

EI (beam 2) = 2EI (beam 1)

The maximum bending stress under the blade flapping load is approximately equal to:

σ (beam 2) = σ (beam 1) (glass fiber composite material position of the upper beam plate)

For ease of comparison, it is assumed that the bending stiffness (EI) of the blade beam structure is the same and is uniformly distributed. According to the cantilever beam calculation, the maximum bending deformation at the blade tip (free end) in the blade flapping direction is approximately equal to:

The Sandia 100-meter All-glass Baseline Wind Turbine Blade: SNL100-00 (Sandia 100m Full Glass Fiber Composite Wind Turbine Blade: SNL100- published in Sandia National Laboratories, USA, June 2011) 00, http://windpower.sandia.gov/other/113779.pdf)" The glass fiber composite E-LT-5500/EP-3 described in the research report has an elastic modulus of 41.8 GPa and a tensile strength of 972 MPa. The compressive strength is 702 MPa and the density is 1950 kg/m ³ .

"Carbon Fiber Reinforced Polymer Cables: Why? Why Not? What If?" by U. Meier in February 2012 (carbon fiber composite rope: Why not? http://link.springer.com/article/10.1007/s13369- 012-0185-6) In the paper, the T700s carbon fiber rope has an elastic modulus of 165 GPa, a tensile strength of 3300 MPa, and a density of 1560 kg/m ³ .

The upper and middle beam plates in the embodiment described above may be the above-mentioned glass fiber composite material E-LT-5500/EP-3, and the blade reinforcement member may be the above-mentioned T700s carbon fiber rope. Thus, the elastic modulus of the T700s carbon fiber rope is four times that of the E-LT-5500/EP-3 (E _c = 4E), and the density of the T700s carbon fiber rope is 80% of the E-LT-5500/EP-3 (ρ _c = 0.8ρ).

Beam 2

In this way, the area

The unit length weights of beam 1 and beam 2 are approximately equal to:

M (beam 1) = 2tbρ

Through the above analysis, the comparison of the blade bending direction bending stiffness, the maximum bending stress, the maximum deformation (tip) and the beam weight of the beam 2 and the beam 1 can be obtained, as shown in Table 1.

Table 1

	弯曲刚度Bending stiffness	最大弯曲应力Maximum bending stress	最大变形(叶尖)Maximum deformation (tip)	主梁重量Main beam weight
梁1(比较例)Beam 1 (comparative example)	11	11	11	11
梁2(本发明)Beam 2 (invention)	22	11	0.50.5	0.550.55

It can be seen from Table 1 that the maximum bending stress of the blade main beam of the embodiment of the present invention is the same as that of the comparative example main beam, but the maximum deformation (tip) is only 50% of the latter, and the blade main beam self-weight is 55% of the latter. . Moreover, the weight of the carbon fiber rope of the embodiment of the present invention is only 5% of the weight of the blade main beam of the comparative example.

It should be understood that, although the description has been described in terms of various embodiments, it is not intended that the embodiment The technical solutions in the respective embodiments may also be combined as appropriate to form other embodiments that can be understood by those skilled in the art. The innovative features disclosed in the specification are not indispensable, and various innovative features can be obtained with other existing configurations, which are all within the scope of the present invention.

The above is only the exemplary embodiments of the present invention and is not intended to limit the scope of the present invention. Equivalent changes, modifications, and combinations of the invention may be made without departing from the spirit and scope of the invention.

List of reference signs

1-blade assembly 26-blade reinforcement

2-blade housing 31-first leg

3-beam structure 32-second foot

4-main beam 33-linker

5-anti-shear web 100-blade

11-connection bracket 101-first leaf segment, root segment

12-linking bracket 102-second leaf segment, middle leaf segment

13-connection bracket 103-third leaf segment, tip segment

14-connection point 311-column piece

15-connection point 312-column piece

21-blade reinforcement 313-beam member

22-blade reinforcement 321-column

23-blade reinforcement 322-column

24-blade reinforcement 323-beam member

25-blade reinforcement 1'-blade

Claims

A reinforced blade assembly (1) comprising: a blade (100), a connecting bracket (11, 12, 13) fixed to the blade (100) and extending longitudinally across the span of the blade, and at least one elongated blade a reinforcing member (21, 22, 23, 24, 25, 26), wherein the blade reinforcing member (21, 22, 23, 24, 25, 26) is configured to be connected to the connecting bracket at least one end (11, 12) And 13) spaced apart from the blade (100).
The reinforced blade assembly (1) according to claim 1, wherein the blade reinforcement (21, 22, 23, 24, 25, 26) is a tensile reinforcement and is configured to be subjected to tensile prestressing.
The reinforced blade assembly (1) according to claim 1, wherein the blade reinforcement (21, 22, 23, 24, 25, 26) is a high strength, high modulus of elasticity material, such as a carbon fiber rope.
The reinforced blade assembly (1) according to any one of claims 1 to 3, wherein at least one of the blade reinforcements (21, 22, 23, 24, 25, 26) is configured to be One end of the blade reinforcement is coupled to the attachment bracket and is directly coupled to the blade (100) at the other end of the blade reinforcement.
The reinforced blade assembly (1) according to any one of claims 1 to 3, wherein at least one of the blade reinforcements (21, 22, 23, 24, 25, 26) is configured to be Both ends of the blade reinforcement are coupled to respective connecting brackets and extend generally parallel to the blades (100).
The reinforced blade assembly (1) according to any one of claims 1 to 3, A plurality of said blade reinforcements (21, 22, 23, 24, 25, 26) are included, wherein:

At least two of the plurality of blade reinforcements (21, 22, 23, 24, 25, 26) are configured to extend longitudinally along the blade in substantially longitudinal alignment and to connect to both sides of the same attachment bracket; and/or

At least two of the plurality of blade reinforcements (21, 22, 23, 24, 25, 26) are configured to extend in the longitudinal direction of the blade in parallel and to the same side of the same connection bracket.
The reinforced blade assembly (1) according to any one of claims 1 to 3, wherein the connecting bracket (11, 12, 13) comprises a first leg (31), and the first leg is in the blade A longitudinally spaced second leg (32) of (100), and a connecting element that securely or integrally forms the first leg (31) and the second leg (32).
The reinforced blade assembly (1) according to any one of claims 1 to 3, wherein the blade (100) comprises a plurality of blade segments (101, 102, 103), the connecting brackets (11, 12) And 13) including a first leg (31) on one of the blade segments, a second leg (32) on the adjacent blade segment, and a first leg (31) and a second leg (32) Connecting elements that are fixedly connected to each other.
The reinforced blade assembly (1) according to any one of claims 1 to 3, wherein the blade (100) comprises a beam structure (3) and a blade shell covering the beam structure (3) (2) ).
A rotor comprising a hub and a plurality of blades coupled to the hub, wherein at least one of the plurality of blades is a reinforced blade assembly according to any one of claims 1-9.
A wind power installation comprising the rotor of claim 10.
A power generation apparatus comprising the rotor according to claim 10, the power generation apparatus being a wind power generation apparatus, a marine flow power generation apparatus, or a power flow generation apparatus.
A method of manufacturing a reinforced blade assembly, comprising the steps of:

Providing a plurality of leaf segments, wherein each leaf segment is fixedly connected or integrally formed with a connecting leg;

Fixing the leaf fragments to each other;

Connecting the connecting legs of adjacent blade segments to each other by means of connecting elements to form a connecting bracket extending longitudinally across the span of the blade;

An elongated blade stiffener is mounted in the blade assembly, wherein at least one end of the blade stiffener is fixedly coupled to the connecting leg.