KR100914674B1 - Method of manufacturing a wind turbine blade shell member - Google Patents

Abstract

A method of manufacturing a wind turbine blade sheath member 2 comprising a plurality of elements 8 of a cured fiber reinforced sheet material is disclosed. A plurality of elements of the cured fibre-reinforced sheath material is provided in the mold, a resin is injected between the elements of the cured fiber-reinforced sheath material, and the elements are joined in close proximity to the elements by curing the resin. This method is particularly suitable for manufacturing wind turbine blade skin members due to the complex three-dimensional shape of the airfoils, which can be similar by the relatively flexible cured fiber reinforced sheet material.

Description

Method of manufacturing a wind turbine blade shell member

The present invention relates to a wind turbine blade skin member comprising a cured fiber reinforced skin material. More specifically, the present invention comprises a cured fiber reinforcement sheet material proximate to the outer surface and is preferably disposed as a partially overlapped tile. A method of manufacturing a wind turbine blade skin member having a material.

Moreover, the present invention relates to a wind turbine blade and a sub assembly comprising a cured fiber reinforced skin material bonded by a cured resin and a wind turbine blade skin member associated with the method.

International patent application publication WO 03/008800 discloses a blade for a wind turbine, the blade comprising a layer of pre-assembled sticks proximate the skin surface. In one embodiment, some of the sticks consist of carbon fiber pultrusion located within the blade while the cross section of the stick is substantially perpendicular to the outer surface of the blade.

It is an object of the present invention to provide a more effective method for producing composite members.

Another object of the present invention is to provide a composite member comprising a cured resin reinforced sheet material bonded by cured resin.

The above and other objects of the present invention are realized by a method of manufacturing a wind turbine blade shell member comprising providing a mold and placing a plurality of elements of the cured fiber reinforced sheet material in the mold. . Thereafter, the curable resin is injected between most elements of the cured fiber reinforced sheet material, and the plurality of elements of the cured fiber reinforced sheet material are joined by curing of the resin. The outer surface layer material and / or the inner surface layer material may also optionally be provided in the mold prior to injection and curing of the resin.

The number of elements can vary considerably depending on the actual application, such as the thickness, shape and size of the elements and the size of the wind turbine blade skin member to be manufactured. Typically, at least three or more elements are used, but when more than one, such as at least five, at least ten or at least fifteen, is used, the overall shape of the finished reinforcement structure can be achieved uniformly. On the other hand, a very large number of elements can be difficult to organize. Although more layers may be used within the scope of the present invention, it is usually desirable to use less than 100, such as less than 75 or less than 50 elements. If a large number of elements are used, the elements are preferably arranged in a sub-assembly-like structure, such as a stack, which can be temporarily fixed to form a loose stack with each other.

The use of cured fiber reinforced sheet material allows for very high fiber content and highly aligned fibers in the elements. Bending or humps in fiber reinforced composite materials, as known in the art, greatly degrade the mechanical properties, in particular the strength and E-modulus of the composite. The production of composites with highly aligned fibers is therefore very desirable. Moreover, the fact that the sheet is cured facilitates the transport of the elements, so that no special conditions such as temperature range or humidity range are required. Moreover, combining the sheet shape with the cured state of the element facilitates the adjustment of the elements to the shape of the mold without compromising the alignment of the fibers in the member, ie the linearity. This is particularly important for complex shapes such as airfoils of wind turbine blades, where the desired fiber distribution is a complex three dimensional shape.

In a very preferred embodiment of the present invention, at least some of the elements of the cured fiber reinforced sheet material are positioned as partially overlapping tiles, thereby providing the edges of a plurality of substantially parallel elements. This allows the elements to be placed very close to the surface of the mold, and by adjusting the overlap between the elements, any desired overall distribution of the reinforcing fibers can be almost realized. In particular, the elements can be located in the cross section of the wind turbine blade so that the fibers are substantially similar to the distribution of water in the lake, having a depth shape corresponding to the distance from the centerline of the blade to the surface of the cross section. In a particularly preferred embodiment, the substantially parallel element edges are the edges substantially parallel to the lengths of the elements of the cured fiber reinforced sheet material. This results in a relatively short resin injection distance and therefore easy production and good reproducibility.

Elements of the cured fiber reinforced sheet material may be provided along a long or short portion of the composite structure length. However, it is desirable for the elements to be located along at least 75% of the wind turbine blade skin member length, and in many cases the cured fiber reinforced sheet material is more preferably located along at least 90% of the composite structure length. .

The cured fiber reinforced sheet material includes fibers, such as carbon fibers, glass fibers, aramid fibers, natural fibers such as cellulose based fibers similar to wood fibers, organic fibers or other fibers. And they can be used for reinforcement purposes. In a preferred embodiment, the fibers are unidirectional fibers oriented parallel to the length of the cured fiber reinforced sheet material. This provides very high strength and rigidity in the length of the cured fiber reinforced sheet material. Other combinations of directionality and directions may be appropriate in some applications. Examples of other suitable orientations are biaxial fibers oriented at ± 45 ° or 0 ° / 90 ° to the length of the sheet material; Triaxial fibers oriented at a length of ± 45 ° and the sheet material. Such directions improve the strength and rigidity of the edge direction and / or torsion of the composite material.

Moreover, the cured fiber reinforced sheet material comprises a resin, preferably a thermosetting resin such as epoxy based resin, vinyl ester based resin, polyurethane based resin or other suitable thermosetting resin.

The cured fiber reinforced sheet material may comprise one or more types of resins and one or more types of fibers. In a preferred embodiment, the cured fiber reinforced sheet material comprises a unidirectional carbon fiber and an epoxy based resin or a vinyl ester based resin, preferably wherein the cured fiber reinforced sheet material is substantially unidirectional carbon fibers and an epoxy based resin. Is made of.

The cured fiber reinforced sheet material is a relatively flat member having a length that is at least 10 times the width and a width that is at least 5 times the sheet material thickness. Typically, the length is 20 to 50 times or more of the width and the width is 20 to 100 times or more of the thickness. In a preferred embodiment, the shape of the sheet material is similar to a band.

The cured fiber reinforced sheet material is preferably dimensioned to be coilable. By winding it is meant that the sheet material can be wound on a roll having a diameter which can be carried in a container of standard size. This significantly reduces the manufacturing cost of the composite material, in which endless coils of cured fiber reinforced sheet material can be manufactured in a concentrated facility and shipped to the blade assembly site, where the coils are divided into elements of the appropriate size. Because it can be. To further improve shipping, the thickness of the cured fiber reinforced sheet material is selected so that the cured fiber reinforced sheet material can be wound on rolls with a diameter less than 2 m based on the flexibility, rigidity, fiber type and fiber content in use. It is desirable to be. Typically this corresponds to a thickness of up to 3.0 mm, but for high fiber content and rigidity, thicknesses smaller than 2.5 mm are always more appropriate. On the other hand, thick sheet materials cut off at the outer surface and provide large steps, which makes thin sheet material preferred. However, the sheet materials typically should not be thinner than 0.5 mm, because a large number of sheets are required, which leads to a long manufacturing period. Experimental work has shown that a thickness of about 1.0 mm provides a good compromise with respect to the number of sheets. Finally, the flexibility of the cured fiber reinforced sheet material should be sufficient for the sheet to match the shape of the mold. In a preferred embodiment, the thickness of the cured fiber reinforced sheet material is about 1.5 to 2 mm.

The width of the cured fiber reinforced sheet material typically varies along the length of the sheet material. Typically, the maximum width should be larger than 100 mm and a width larger than 150 mm is desired to reduce the number of sheets.

In many cases, experimental work shows that it is desirable to have a width greater than 200 mm in the widest part. On the other hand, the resin must move between adjacent sheets in length corresponding to the width of the sheet and therefore the maximum width of the sheet material should preferably be smaller than 500 mm to allow proper control of resin injection. In a preferred embodiment, the maximum width is less than 400 mm and, for example, if the resin is chosen so that the resin starts to cure before full injection, the maximum sheet width is preferably less than about 300 mm.

In a preferred embodiment of the method according to the invention, the cured fiber reinforced sheet material is pretreated before being placed in the mold. Examples of pretreatment include, for example, sandblasting, cleaning of surfaces by mechanical and / or chemical means, for example drying or heating, for example by changing the mechanical bond with the resin or by changing the surface texture (see below). Acclimatising to the environment. One or more pretreatment types of cured fiber reinforced sheet material may be appropriate depending on the conditions of use.

The cured fiber reinforced sheet material should comprise highly aligned fibers so that the cured fiber reinforced sheet material may advantageously be a pultrusion cured composite material or a belt pressed cured composite. These techniques provide high fiber content of fibers highly aligned to the desired sheet shape. In addition, these techniques are particularly suitable for the manufacture of infinite lengths of materials.

It can be very difficult to inject resin between sheets of material if the sheets are placed in close proximity. This is especially the case when the space between the sheets is subjected to a vacuum. In a preferred embodiment of the invention, the cured fiber reinforced sheet material is provided with a surface texture that facilitates the injection of the resin between adjacent elements of the cured fiber reinforced sheet material. The surface texture may include resin protrusions of a height that is preferably about 0.1 mm to 0.5 mm above the major surface of the cured fiber reinforced sheet material, but in some cases, such as when the injection distance of the resin is relatively large The overhang can be larger.

Additionally or alternatively, the surface tissue may comprise recesses, such as channels, into the major surface of the cured fiber reinforced sheet material, preferably the recesses are on the order of 0.1 mm to 0.5 mm below the major surface, but in some cases Larger parts may be appropriate. Typically, the protrusions and / or recesses are separated by 1 cm to 2 cm, but the spacing may be larger or smaller depending on the actual size of the corresponding protrusions and / or recesses.

The surface textures of the types described above may be provided after the manufacture of the cured fiber reinforced sheet material, for example by sandblasting, grinding or dripping the semi-solid resin onto the surface, but the cured fiber reinforced sheet Preferably, the surface tissue that facilitates resin injection between adjacent elements of the material is provided at least in part during the manufacture of the cured fiber reinforced sheet material. This is particularly easily made when the hardened fiber reinforced sheet material is produced by belt pressing since the surface texture can be induced through a negative template on the belt surface texture of the belt press. In another embodiment, a foil is provided between the belt and the fiber reinforced sheet material being formed in the belt press. Such foils can act as liners and must be removed prior to the introduction of the cured fiber reinforced sheet material in the mold.

In a preferred embodiment, the effect of surface tissue facilitating resin distribution during resin injection is realized by providing a plurality of inner spacer elements between adjacent elements of the cured fiber reinforced sheet material. The inner spacer elements are advantageously from one or more members of the group consisting of fibers such as glass fibers and / or carbon fibers, solid materials such as sand particles, and high melting point polymers such as, for example, resin points or lines. Can be selected. The inner spacer elements are inert during resin injection, for example, preferably the shape does not change or does not react with the injected resin. Using inner spacer elements can be advantageous in many cases, which is relatively costly and does not require any particular method of manufacturing the cured fiber reinforced sheet material or the special preliminary treatment of the cured fiber reinforced sheet material. Because it does not. The inner spacer elements preferably range in size from 0.1 mm to 0.5 mm and are typically separated by 1 cm to 2 cm, but both sizes and spacings may be appropriate in some cases. Typically, as the inner spacing element becomes large, it may be acceptable to widen the spacing.

This process can advantageously be assisted with a vacuum to facilitate resin injection. In this case, the method further includes forming a vacuum enclosure around the composite structure. The vacuum enclosure may be preferably formed by providing a second mold portion that is flexible in vacuum tight communication with the mold. The vacuum is then vacuumed by vacuum means such as a pump in communication with the vacuum enclosure so that the resin can be injected by a vacuum assisted process such as vacuum assisted resin transfer molding. Can be provided in Vacuum assisted processes are particularly suitable for large structures, such as wind turbine blade skin members, because long resin transport distances can result in premature resin hardening, which can further inhibit resin infusion. Moreover, the vacuum assist process will reduce the amount of air in the wind turbine blade shell member and thus the presence of air in the injected composite will decrease, which increases strength and reproducibility.

The composite member, which may be produced by the process according to the invention or according to the invention, forms a wind turbine blade when it is connected to one or more other composite members, for example by mechanical fastening means and / or adhesives. Wind turbine blade sheaths can be formed or individually. From such wind turbine blade sheaths, a wind turbine blade can advantageously be produced by joining two said wind turbine blade sheaths with adhesive and / or mechanical means such as fixtures. Both the wind turbine blade sheath and the combined wind turbine blade may optionally include other elements, such as regulating elements, light emitting conductors, and the like. In a particularly preferred embodiment, each blade sheath consists of a composite member which can be produced by the method according to the invention. In another preferred embodiment, the wind turbine blade sheath member produced by the method according to the invention substantially forms the complete outer sheath of the wind turbine blade, ie the pressure side formed integrally during the manufacture of the wind turbine blade sheath member. It forms a pressure side and a suction side.

One feature of the present invention relates to a wind turbine blade comprising a cured fiber reinforced sheet material. The cured fiber reinforced sheet material is positioned close to the outer surface of the blade as a partially overlapping tile. In a preferred embodiment, the cured fiber reinforced sheet material is a cured fiber reinforced sheet material that has been pultruded or band pressed and divided into elements of the cured fiber reinforced sheet material.

In another preferred embodiment, the wind turbine blades according to the invention have a length of at least 40 m. The ratio of the thickness t to the chord C (t / C) is substantially constant for the airfoil portions in the range between 75% <r / R <%, where r is the blade root The distance from the part, R is the overall length of the blade. Preferably, a constant thickness for the chord is realized in the range of 70% <r / R <95%, more preferably in the range of 66% <r / R <95%. This can be realized in the wind turbine blades according to the invention, since the packing of the fibers in the areas of the blade cross section is very dense and the parts provide a high moment of inertia. Thus, according to the invention it is possible to achieve the same moment of inertia with less reinforcing material and / or to achieve the same moment of inertia in a thinner shape. This is desirable because it saves material and enables airfoil design that conforms to aerodynamic requirements rather than structural requirements.

The invention will next be described in more detail with reference to exemplary embodiments and figures.

1 shows a cross section of a wind turbine blade shell member in a mold.

2 shows a wind turbine blade skin member having two layers of partially overlapping elements.

3 shows a cross section of a wind turbine blade with reinforcing fibers.

4 illustrates various overall reinforcement structures.

5 shows a preferred method of making a sub-assembly of an element by dividing the cured fiber-reinforced sheet material.

6 shows a preferred resin delivery path during the injection of the resin.

FIG. 7 shows details of the resin delivery paths of FIG. 6.

8 shows the element thickness effect of the cured fiber reinforced sheet material.

9 shows a group arrangement of elements.

All figures are very schematic and are not necessarily to scale, they only show the parts necessary to illustrate the invention, other parts are omitted or suggested only.

In FIG. 1, an example of a wind turbine blade shell member 2 formed in accordance with the method of the invention is shown in a mold 4. The mold 4 is typically a rigid member and can be combined with the second mold portion (see element 5 in FIG. 6) during the injection of the resin. Typically such a second mold can be flexible. Optionally, outer surface layer material 10 is located in the mold. Such outer surface layer 10 may be, for example, a prepreg or thermoplastic coating material. Next, a plurality of elements 8 of the cured fiber reinforced sheet material are placed in the mold. Core elements 36 and other elements such as, for example, light emitting conductor systems, control systems and wind turbine blade monitor systems may be provided at this stage.

If desired, an optional inner surface layer material 12 may be provided over the elements 8 of the cured fiber reinforced sheet material. An optional inner surface layer material may be provided after resin is injected between the elements, but the presence of the inner surface layer material is not essential to the wind turbine blade skin member. The outer surface layer material as well as the inner surface layer material may comprise fibers, which are oriented differently from the cured fiber reinforced sheet material elements fibers and thus, for example, increase the lateral strength of the wind turbine blade skin member.

Finally, the resin is injected between the elements. While it is desirable for all spaces between adjacent elements to be filled with resin, partial filling may not be sufficient in some cases. To facilitate the injection of the resin, the air between adjacent elements can be removed prior to the injection of the resin, for example by a vacuum as described elsewhere.

In the preferred embodiment illustrated in FIG. 2, the plural elements 8 of the cured fiber reinforced sheet material, which are provided as partially overlapping elements, are arranged in elements of at least two layers 14. In FIG. 2, this is illustrated by two layers 14, but larger wind turbine blade shells in which more layers, such as three, four, five, six or more layers, have a very thick reinforcement structure. It may be advantageous for the members. Elements in other layers may be similar (not shown) or otherwise oriented as shown in FIG. 2. The layers 14 may be separated by a member 34, such as a fibrous layer or surface spacer element 34 (see below), to facilitate dispensing of the resin and / or a uniform base for subsequent layers. Get

The resin may be injected into the layers of elements in one operation or stepwise operation, with resin initially poured into one or more layers, where the resin in these layers is injected into one or more other layers of elements. Previously cured. Such a stepwise method may comprise two or more steps, two, three, four, five or more in the case of a very thick overall reinforced structure.

One of the major advantages of using cured fiber reinforced sheet material elements is that the reinforcement material can be positioned with very high design freedom. In general, the reinforcing material is preferably located as far from the centerline of the structure as possible to achieve high momentum strengthening. By using overlapping elements, this can be achieved substantially by a plurality of elements having the same shape, or in situations where an overall reinforcing structure of a complex geometric shape is desired, only a plurality of elements having several different shapes can be used. Can be achieved by This is possible by varying the degree of overlap and the angles between the outer surface of the composite surface and the elements of the cured fiber reinforced sheet material.

3 shows an example in which elements are distributed in a mold. Elements 8 of the cured fiber reinforced sheet material are located along the outer surface, and core elements (not shown) may be placed away from the outermost surface to ensure proper positioning of the elements. The core elements are lightweight structures with limited reinforcement performance. In a preferred embodiment, this is applied to the wind turbine blade such that at least 80%, preferably 90% of the fibers in the cross section of the blade perpendicular to the longitudinal direction of the blade are arranged in the combined volume of the outermost volume. Said portions of the fibers are arranged at the outermost 20 or 30 vol-% of the pressure side or the blowing side and at the outermost 20 or 30 vol-% of the suction side or the blowing side. In the shape of half of FIG. 3, a portion of the outermost part is indicated by line 16 and the central plane of the shape is indicated by line 18. This arrangement is very desirable because increased moments of inertia are possible for a given amount of reinforcement. In a preferred embodiment, the distribution of such fibers is such that the ratio of the distance r from the wind turbine blade root portion to the total length R of the wind turbine blade root portion is in the range of 50% <r / R <75%. For the cross section, it is preferably realized for the cross section in the range between 25% <r / R <75%. In a very preferred embodiment, the fibers are carbon fibers.

Elements of the cured fiber reinforced sheet material may be produced by dividing the cured fiber reinforced sheet material, advantageously by cutting. Due to the fiber properties of the cured fiber reinforced sheet material, it is desirable to use a water jet to avoid relying on the wear of traditional cutting tools, but other methods can be used within the scope of the present invention. .

In FIG. 5, an example of a method of dividing a band-shaped cured fiber reinforced sheet material is described. It is desirable to shape the elements such that a relatively sharp tip is formed at least near one end, since the stack of partially overlapping elements will be similar to the overall chamfering of the reinforcing fiber contents towards the end. This is especially the case if the tip of the element is formed by the intercept of two relatively straight edges.

In the preferred embodiment shown in FIG. 5A, at least one of the elements 8 of the cured fiber reinforced sheet material 6 is divided so as to correspond to a first end corresponding to the first end of the wind turbine blade sheath member 2. Toward the tip 24 to form a first tip angle α. In a more preferred embodiment, the first tip angle α is along a straight line indicated by dashed lines from the first sheet edge 20 to the second sheet edge 22 of the cured fiber reinforced sheet material 6 in FIG. 5A. It is formed by dividing the cured fiber reinforced sheet material 6. For an elongated composite structure supported only close to one end, such as a wind turbine blade, momentum increases linearly from the end of the unsupported end towards the supported end. The strength of the elements is substantially proportional to the cross section of the element, and the elements typically play a major part of the structural strength. It is therefore very advantageous for the sum of the cross sections of the elements (also referred to as the overall reinforcing structure) to increase substantially linearly from the first tip end. According to the invention, this can be easily realized by using individual elements having a first tip angle α, which is formed by dividing the cured fiber reinforced sheet material along a straight line as described above.

Another preferred embodiment is shown in FIG. 5A. Here, at least one of the elements 8 of the cured fibre-reinforced sheet material 6 is directed toward the second end 26 corresponding to the second end of the wind turbine blade sheath member 2. divided to form β). In a more preferred embodiment, the second tip angle β is along a straight line indicated by dashed lines from the first sheet edge 20 to the second sheet edge 22 of the cured fiber reinforced sheet material 6 in FIG. 5A, It is formed by dividing the cured fiber reinforced sheet material 6. In particular, for elements or subassemblies 8 that are applied in the manufacture of wind turbine blades, it is preferred that the second tip angle β is greater than the first tip angle α.

In order to save the cured fiber reinforced sheet material by avoiding or at least reducing it, the width of the element or subassembly 8 of the cured fiber reinforced sheet preferably corresponds to the width of the cured fiber reinforced sheet material.

The element or subassembly 8 of FIG. 5 is more advantageous in that the same elements can be formed without any part of the cured fiber reinforced sheet material being wasted during the splitting of the cured fiber reinforced sheet material. Elimination of waste can be realized for not only triangular elements (FIG. 5C) with heights corresponding to the width 40 of the cured fiber reinforced sheet material (FIG. 5B) but also for trapezoidal shaped elements (FIG. 5B).

The element 8 is a subassembly for the manufacture of the turbine blade skin member according to the invention, which can be manufactured in the field in close connection with the fabrication and manufacture of the complete wind turbine blade skin member or the subassembly of the composite structure. It can be manufactured away from the manufacturing site. The subassembly may include one or more features under the same considerations that have been described with respect to the elements or cured fiber reinforced sheet materials, wherein the features may include a material content, an improved surface texture, an inner portion secured to the subassembly. Such as surface spacer elements, manufacturing methods, shapes, sizes and thicknesses. The subassembly can be delivered with the flat elements stacked, or can be coiled or bent into a suitable shape. The subassemblies of the element may be integrated with another subassembly, which includes stacking the subassemblies, optionally with other elements such as mechanical fixtures or adhesives that hold the elements together at least temporarily. Include. Both types of subassemblies can be advantageously used in the manufacture of wind turbine blade skin members as the flexibility of the subassembly is suitable for the requirement to form a three dimensional shape of a blade air foil.

The elements of the cured fiber reinforced sheet material may be arranged to form the reinforcement structure in various overall shapes. Typically, the elements are arranged as shown in FIG. 4A so that one leg faces the first end of the wind turbine blade skin member to be manufactured and one leg forms a reinforcement structure facing the second end of the composite structure. However, in a preferred embodiment, the element 8 of the cured fiber reinforced sheet material 6 is positioned in the mold 4 to form the entire reinforcement structure, which is the first end of the wind turbine blade shell member. At least two legs facing the first end 24 and / or at least two legs facing the second end 26 corresponding to the second end of the composite structure.

4B-4D show examples of reinforcing structures having one or more legs towards at least one end. In FIG. 4B, the entire reinforcement structure has one leg facing the first end and two legs facing the second end. 4C and 4D, the overall reinforcing structure has two legs facing the first end and the second end. The overall reinforcement structures shown in FIG. 4 are particularly advantageous in that in addition to providing tensile strength, the reinforcement structures provide increased torsional strength and stiffness and / or edge strength and rigidity. This is particularly advantageous for long and relatively slim structures, such as wind turbine blades and wind turbine blade sheath members.

If the elements of different legs overlap at one or more sites, it is desirable that the elements of the legs are interlaced with each other to implement an increase in the connection between the elements of the individual legs. Since the individual elements can be handled without bending the fiber in the elements, such interlacing is particularly easy for wind turbine blade skin members having elements of cured fiber reinforced sheet material.

The overall reinforcement structure tends to be very thick at the site where the elements of the individual legs overlap. This may lead to local bending of the fibers in the elements, or inadequately using many resins in areas proximate such overlapping sites to prevent local bending. 4D shows a reinforcing structure having a particular embodiment of elements of the cured fiber reinforced sheet material. The elements are provided with at least partially corresponding areas of overlap, with reduced width. Thereby the overall thickness of the reinforced structure of these areas is reduced. In another embodiment, the elements are provided with at least partially corresponding regions of overlap, with reduced thickness (not shown in the figures). In general, embodiments with a reduced width are more preferred, since such elements can be easily manufactured by cutting a coil of cured fiber reinforced sheet material.

Accurately positioning the elements of the cured fiber reinforced sheet material in the mold can be facilitated by using template means that indicate the desired positions. This is particularly the case when more complex systems of systems are desired or when manual framing is used. The template means may indicate the relative position of the hardened fiber reinforced sheet material elements towards the end corresponding to the end of the wind turbine blade sheath member and / or features or molds of the mold, such as holes or taps. Like the edge of, it may indicate the relative position of at least one element with respect to the mold. The indication of the correct position includes the longitudinal position, the width position and / or the height position relative to the mold and / or to other elements of the cured fiber reinforced sheet material or other elements that must be included in the composite structure. can do.

The template means may be integrated into the wind turbine blade skin member such that it is a template for a single use. In a preferred embodiment, the template means is integrated with the core element of the composite structure.

For large elements such as wind turbine blades, the length of the cured fiber reinforced sheet material elements is typically on the order of the total length of the wind turbine blade, several template means, for example one at each end and blade It may be advantageous to apply one, two, three or more to selected locations along the length of.

The elements of the cured fiber reinforced sheet material are joined together by a resin as described above, but during the weaving, the elements of the cured fiber reinforced sheet material are at least temporarily in the mold and / or other elements in the mold, eg For example, it is very advantageous to secure it to one or more cured fiber reinforced sheet material elements or other types of elements. The temporary fixation should be formed so that such fixation does not lead to unacceptable defects during subsequent resin infusion or during use of the final product. One or more adhesives such as, for example, curable or uncured hot melt resins or double coated tapes; Or mechanical fastening means such as clamps, wires, looped wires or elastic members are included for fastening. In a particularly preferred embodiment, the means for temporary fixation are not removed prior to injection of the resin and thus included in the finished composite structure. In this case, the means for temporary fixation are compatible with the elements of the final structure in chemical relations (e.g. with resins) and mechanical relations (e.g. no formation of mechanically fragile sites). It is important.

In a preferred embodiment, the elements of the cured fibre-reinforced sheet material are located along two to four, preferably three mold plates, proximate and apart from the ends. The elements are temporarily fixed in the desired locations by hot melt of the same type of resin that must be injected to bond the elements, and the templates are removed before the injection of the resin.

For a curved mold such as a cross section of the mold for the wind turbine blade skin member as shown in FIGS. 6 and 7, the resin can be advantageously injected between the elements from the convex side. Since the rigid mold 4 is typically convex, this is typically because resin is injected close to the outer surface through the rigid mold 4 or through the second flexible mold 5 and through the wind turbine blade skin member. To be. This is mainly due to the spacing between the elements, which is larger on the convex side than on the concave side, as indicated by arrows 50 and 52 in FIG. 7. 6 shows a preferred route of resin injection. Here, the resin is injected close to the outer mold via the resin passage 43 in the core element 36 via the second mold 5, but other resin delivery paths are also feasible. From the adjacent mold surface, resin is injected between the elements 8. In addition to the wide access to the space between the elements 8, the injection of the resin from the adjacent mold towards the second mold allows for the observation of complete resin injection during the process, in which the resin is close to the second mold and the wind turbine blade This is because it must penetrate the surface of the shell member. The resin here can be visually observed, especially if the second mold part is transparent or if transparent windows are provided in the second mold part.

As shown in FIG. 6, in a particularly advantageous arrangement of the structural elements of the composite and the mold to be produced, the elements 8 of the cured fiber reinforced sheet material are for example the leading edge L of the wind turbine blade shell member. 1) or partially overlap, starting from the first side of the mold, corresponding to the terminal edge T (FIG. 1). The resin injection passage is arranged to be close to the element 8 of the fiber reinforced sheet material cured away from the first side of the mold, which corresponds, for example, to the terminal edge T or the leading edge L. The excess resin can be advantageously extracted in close proximity to the first side of the mold proximate to the surface of the second mold, respectively corresponding to the leading edge L or the terminating edge T. Such arrangements allow for relatively straight line resin delivery, which reduces the likelihood of blocking the resin distribution path and thus provides a more robust design.

The elements 8 are relatively flexible in directions perpendicular to the plane of the element 8 and thus coincide with the inner surface of the mold 4 by fixing. However, the elements 8 are relatively rigid in the direction of the plane of the element 8 and thus tend to form sharp connecting lines to the mold. Such linkages dramatically suppress resin transport transverse to the linkages.

It is known to provide a flexible open web close to the surface of the composite structure to facilitate the injection of the resin. However, since the flexible webs are simply deformed by the high local pressure created by the edges of the elements 8, such flexible webs will be substantially ineffective if the elements are relatively hard in this case. The inventor has realized that in such cases the surface spacer element 34 should also be rigid. The experiment shows that a composite material comprising fibers and cured resin, while having an open structure such as a lattice or grate, retains resin transport in the transverse direction at the connection between the elements 8 and the edges of the mold 14. It will be possible. It has been found that composites made of cured glass fiber reinforced lattice or other open structures provide a particularly advantageous structure for surface spacer elements because the glass fibers are very suitable and relatively thick. In a particularly preferred embodiment, the cured grating is an open biaxial structure. The grating may advantageously be oriented with respect to the edge of the cured fiber reinforced structural sheet material such that the edges are not parallel in either direction in the biaxial direction, which is the possibility of accidental blocking of resin transport through the surface spacer element below the edges. Because it reduces.

In addition to facilitating resin transport, surface spacer materials may also contribute to the mechanical strength of the composite structure, particularly with regard to strength perpendicular to the main direction of the reinforcing fibers of the cured fiber reinforced sheet material. This is mainly due to the fact that the fibers of the surface spacer material are typically placed in an arrangement that is not parallel to the main direction of the reinforcing fibers of the cured fiber reinforcing sheet material. A typical and preferred orientation of the biaxial surface spacer material is ± 45 ° with respect to the main direction of the reinforcing fibers of the cured fiber reinforcing sheet material.

The flexibility of the element 8 decreases as the thickness of the element increases. Moreover, as the thickness of the elements increases, the steps between the edges of the individual elements increase. This is shown in FIG. 8, where a stack of partially overlapping elements 8 of the cured fiber reinforced sheet material is schematically illustrated. In FIG. 8A, two stacks are shown, the stack to the left having thick elements 8 and the stack to the right having thin elements 8. It is observed that the triangular space 38 between the elements and the outer mold is larger for the thick elements 8 than for the thin element 8. This is due to the flexibility of the resin filling the triangular space 38 and other elements in the finished composite structure and / or thermal shrinkage or curing shrinkage of the resin, for example, based on deviations in thermal expansion. The wavy outer surface texture of the finished wind turbine blade skin member as can be achieved.

In FIG. 8C, how the cured material, such as surface spacer elements as described above, tends to form wavy outer surface tissue by reducing the dependence of the surface properties on the thickness of the elements and the properties of the resin. It is shown if it can be reduced or eliminated.

In a preferred embodiment, the plurality of elements of the cured fiber reinforced sheet material comprises at least two types of fibers. The fibers are preferably selected from the group consisting of carbon fibers, glass fibers, aramid fibers and cellulose based fibers and preferably natural fibers such as wood fibers.

The fibers may be arranged such that one or more elements comprise two or more fiber types, such as a combination of carbon fibers and wood fibers or a combination of carbon fibers and glass fibers. In a particularly preferred embodiment, the plurality of elements comprises a first group of elements having a first fiber composition and a second group of elements having a second composition. Preferably, the first fiber composition consists essentially of carbon fibers so that the elements of the first group are particularly hard in proportion to the weight and volume of the cured fiber reinforced sheet material. The second fiber composition may comprise, for example, wood fibers and / or glass fibers. There may be two or more groups of elements, three, four, five, six or more groups.

In one embodiment of the invention, the shape of the elements is similar for all the elements regardless of the group to which they belong. In other embodiments, the shapes of elements belonging to different groups are not similar. In a third embodiment, the shape of the elements is varied within an individual group of elements.

Preferred combinations of elements

a) a group of elements reinforced by carbon fibers in combination with a group of elements reinforced by glass fibers;

b) a group of elements reinforced by carbon fibers in combination with a group of elements reinforced by wood fibers;

c) a group of elements reinforced by carbon fibers in combination with a group of elements reinforced by wood fibers and a group of elements reinforced by glass fibers.

These groups are particularly useful for the fabrication of elements for wind turbine blade sheaths, since reinforcement requirements, including the requirements of stiffness and strength, vary with distance from the blade root portion. Thus, this type of combination using the cured fiber reinforced sheet material technology according to the present invention will provide a structurally superior and suitable blade.

The elements of the groups can be placed in a mold or final product such that at least some of the elements of the two groups are placed end to end as shown in FIG. 9A. Here, 'c' represents elements of the cured fiber reinforced sheet material mainly reinforced by carbon fibers, and 'g' represents elements of the cured fiber reinforced sheet material mainly reinforced by glass fibers, and 'w' Represents elements of a cured fiber reinforced sheet material that is primarily reinforced by wood fibers, only one layer of elements is shown for clarity, in fact many layers will be used for the composite structure, typically each The layers of are slightly spaced apart with respect to adjacent layers, for example as shown in FIG. 4, allowing the properties to change more gradually.

9b shows another preferred arrangement of the groups of elements. Here, elements of different groups partially overlap with adjacent groups. The overlap may cover only a small portion of the element site or may be a substantially complete overlap. It is desirable to gradually reduce the width of the element at the overlapping site so that the properties of the overall reinforcing structure change more gradually. The number of elements does not have to be the same for all groups. For example, elements with carbon fibers are harder than others and are typically disposed within narrow portions of the structure, so that elements with carbon fibers are typically needed less than elements with wood or glass fibers.

In addition to the apparent modifications of the invention described herein, the individual features or combinations of features of the embodiments, if the skilled person will readily realize that the resulting combination is not physically possible, the other implementations described herein It may be exchanged or combined with the features of the examples.

The present invention can be used to manufacture wind turbine blades.

<Code of Drawing>

2. Wind turbine blade jacket member 4. Mold

5. Second mold portion 6. Cured fabric reinforced sheet member

8. Elements of Cured Fabric Reinforced Sheet Member

9. Element Edge of Cured Fabric Reinforced Sheet Member

10. Outer surface layer material 12. Inner surface layer material

14. Layer of partially overlapping elements 16. Part of the outermost part

18. Centerline 20. First Sheet Edge

22. Second sheet edge 24. First tip end

26. Second tip end 34. Surface spacer element

delete

36. Core Elements 38. Triangle Space

40. Maximum Width 42. Dividing Line

43. Resin Path 44. Resin Inlet

46. Resin Outlet 50. Spacing on Convex Side

53. Spacing of concave side α. First tip angle

β. 2nd tip angle

Claims (54)

Providing a mold 4, Positioning the plurality of elements 8 of the cured fiber reinforced sheet material 6 as a partially overlapping tile in the mold, Optionally providing the outer surface layer material 10 and / or the inner surface layer material 12 into the mold 4, Injecting a curable resin (not shown) between substantially all of the elements 8 of the cured fiber reinforced sheet material 6, and Bonding the plurality of elements (8) of the cured resin reinforced sheet material (6) by curing the resin. The method of claim 1, A method of manufacturing a wind turbine blade shell member (2) in which at least some of the elements (8) of the cured fiber reinforced sheet material (6) are positioned so that a plurality of substantially parallel element edges (9) are provided. The method of claim 2, At least two layers of elements (8) of the cured fiber reinforced sheet material (6) are positioned as partially overlapping elements. The method of claim 3, wherein The resin is injected in one operation to all layers of the elements (8) of the cured fiber reinforced sheet material (6), which are positioned as partially overlapping elements. The method of claim 3, wherein The resin is cured fiber reinforced sheet material positioned as partially overlapped elements before the resin is injected into another layer of elements 8 of cured fiber reinforced sheet material 6 positioned as partially overlapped elements. A method of making a wind turbine blade skin member (2), which is injected into a first layer of elements (8) of (6). The method of claim 1, The elements (8) of the cured fiber reinforced sheet material (6) are positioned along at least 75% of the length of the wind turbine blade skin member (2). The method of claim 1, The cured fiber reinforced sheet material (6) comprises glass fibers and / or carbon fibers and / or wood fibers and thermosetting resins. The method of claim 7, wherein The cured fiber reinforced sheet material (6) mainly comprises unidirectional fibers. The method of claim 1, The cured fiber reinforced sheet material (6) is coilable, wherein the wind turbine blade shell member (2) is made. The method of claim 9, The cured fiber reinforced sheet material 6 has a thickness such that the cured fiber reinforced sheet material 6 can be wound onto a roll with a diameter smaller than 2 m. . The method of claim 1, The width of the cured fiber reinforced sheet material (6) is greater than 100 mm and less than 500 mm. The method of claim 1, The width of the cured fiber reinforced sheet material (6) is larger than 200 mm and smaller than 400 mm. The method of claim 1, The cured fiber reinforced sheet material (6) is provided with a surface structure that facilitates the injection of resin between adjacent elements of the cured fiber reinforced sheet material. The method of claim 1, The cured fiber reinforced sheet material (6) is sandblasted, and / or cleaned and dried before being placed in the mold. The method of claim 1, The cured fiber reinforced sheet material (6) is a cured pultruded composite or a cured belt pressed composite. The method of claim 15, The surface texture that facilitates resin injection between adjacent elements 8 of the cured fiber reinforced sheet material 6 is provided at least in part by belt pressing during the manufacture of the cured fiber reinforced sheet material 6. Method for manufacturing wind turbine blade skin member (2). The method of claim 1, And further comprising dividing the cured fiber reinforced sheet material (6) into elements (8) of the cured fiber reinforced sheet material. The method of claim 1, At least one of the elements 8 of the cured fiber reinforced sheet material 6 has a first tip angle α towards the first end 24 corresponding to the first end of the wind turbine blade sheath member 2. A method of manufacturing a wind turbine blade skin member (2), which is divided to form. The method of claim 18, At least one of the elements 8 of the cured fiber reinforced sheet material 6 has a second tip angle β towards the second end 26 corresponding to the second end of the wind turbine blade sheath member 2. A method of manufacturing a wind turbine blade skin member (2), which is divided to form. The method of claim 19, The width of the element (8) portion of the cured fiber reinforced sheet material (6) corresponds to the width of the cured fiber reinforced sheet material (6). The method of claim 1, The element 8 of the cured fibre-reinforced sheet material 6 is a triangular or trapezoidal quadrangle having a height corresponding to the width 40 of the cured fibre-reinforced sheet material 2. Way. The method of claim 1, At least part of the elements (8) of the cured fiber reinforced sheet material (6) are located in the mold (4) according to the template means. The method of claim 22, The template means are integrated in the wind turbine blade sheath member (2). The method of claim 1, Further comprising at least temporarily securing the elements of the cured fiber reinforced sheet material to the mold and / or other elements in the mold. The method of claim 1, The elements 8 of the cured fiber reinforced sheet material 6 are located in the mold 4 to form a total reinforcing structure, the entire reinforcing structure corresponding to the first end of the wind turbine blade sheath member. 24. A method of making a wind turbine blade skin member (2) having at least two legs facing 24 and / or at least two legs facing a second end (26) corresponding to a second end of the wind turbine blade skin member. The method of claim 25, The elements 8 of the cured fiber reinforced sheet material 6 are positioned in the mold 4 to form the entire reinforcement structure, which is directed toward the first end 24 of the wind turbine blade shell member. A method of making a wind turbine blade sheath member (2) having at least one leg further facing the second end (26) of the wind turbine blade sheath member. The method of claim 25, At least some of the elements 8 of the cured fiber reinforced sheet material 6 belonging to different legs facing at least one of the ends 24, 26 are interlaced, the wind turbine blade sheath member 2. ) Manufacturing method. The method of claim 25, The width and / or thickness of at least a portion of the elements (8) of the cured fiber reinforced sheet material (6) is reduced in the portions having overlapping legs, the method of manufacturing a wind turbine blade shell member (2). The method of claim 1, A plurality of inner spacer elements are provided between adjacent elements 8 of the cured fiber reinforced sheet material 6 to facilitate dispensing of the resin between the adjacent elements 8 during injection of the resin, The inner spacer elements are A collection of fibers such as glass fibers and / or carbon fibers; Solid material such as sand particles; And A high melting point polymer; selected from one or more members of the group consisting of: a wind turbine blade skin member (2). The method of claim 1, Cured fibre-reinforced sheet material 6 element 8 to facilitate distribution of the resin transversely to the sheet edges 20, 22 of element 8 of the cured fiber-reinforced sheet material 6 during resin injection. Providing the surface spacer element 34 proximate the sheet edges 20, 22 of The surface spacer element is a fully cured fiber reinforced polymer, and the surface spacer element is a migration of the resin without collapse under pressure from the sheet edges 20, 22 of the cured fiber reinforced sheet material 6 element 8. A method of manufacturing a wind turbine blade skin member (2) having an open structure allowing (). The method of claim 30, The spacer element is a hardened lattice structure. The method of claim 1, Forming a vacuum enclosure around the wind turbine blade shell member, Further comprising providing a vacuum in the vacuum enclosure such that the resin can be injected by a vacuum assisted process such as vacuum assisted resin transfer molding (VARTM). The manufacturing method of (2). The method of claim 1, The curable resin is mainly injected between adjacent elements (8) of the hardened fiber reinforced sheet material (6) from the adjacent mold surface. The method of claim 32, The resin is injected into the proximal surface of the mold (4) through the flexible second mold portion (5) and via the resin passageway. The method of claim 34, wherein Air being replaced by resin and / or excess resin is extracted close to both the leading edge (L) and the trailing edge (T). A method of manufacturing a wind turbine blade comprising the steps of connecting two blade skins, each blade skin being at least one wind turbine blade skin manufacturable by the method according to claim 1 by adhesive and / or mechanical means. A method of manufacturing a wind turbine blade, comprising a member. The method of claim 1, The plurality of elements of the cured fiber reinforced sheet material comprise at least two types of fibers. A wind turbine blade comprising a cured fiber reinforced sheet material (6) positioned proximate to an outer surface as a partially overlapping tile. The method of claim 38, At least 80% of the carbon fibers in the cross section perpendicular to the length of the blade have a ratio of the distance r from the wind turbine blade root portion to the total length R of the wind turbine blade root portion 50% <r / R Wind turbine blades, arranged in a combined volume of the outermost 20 vol-% on the pressure side and the outermost 20 vol-% on the suction side, for a cross section in the range <75%. The method of claim 38, With a length of at least 40 m, the ratio (t / C) of the thickness (t) to chord (C) is substantially for airfoil portions in the range between 75% <r / R <95%. As a constant, wind turbine blade. The method of claim 38, The elements 8 of the cured fiber reinforced sheet material 6 form an overall reinforcing structure, which structure comprises at least two legs and / or wind turbine blades facing the first end 24 of the wind turbine blade sheath member. A wind turbine blade having at least two legs facing the second end (26) of the skin member. The method of claim 40, The elements 8 of the cured fiber reinforced sheet material 6 are joined to form a full reinforcing structure, the overall reinforcing structure being directed toward the first end 24 of the wind turbine blade skin member. Having at least one leg further towards the second end (26) of the wind turbine blade. 42. The method of claim 41 wherein At least some of the bonded elements 8 of the cured fiber reinforced sheet material 6 belonging to different legs facing at least one of the ends 24, 26 are interlaced. 42. The method of claim 41 wherein The wind turbine blade, wherein the width and / or thickness of at least some of the elements 8 of the cured fiber reinforced sheet material 6 is reduced in portions having overlapping legs. delete delete delete delete delete delete delete A wind turbine blade comprising a composite member manufacturable by the method according to claim 1. Subassembly comprising an element (8) of cured fiber reinforced sheet material (6), said subassembly being suitable for application in the method according to claim 1. delete

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