KR20090113205A - A composite wind turbine tower and a method for fabricating same - Google Patents

Abstract

PURPOSE: A complex wind force turbine tower and a manufacturing method thereof are provided to reduce the energy cost and increase the electric power productivity. CONSTITUTION: A flexible fabric preform(36) is formed by weaving a fiber tow(52) with the shape corresponding to the form of a tower or part thereof. A complex shell or section thereof is formed by laminating the flexible fabric preform. Before laminating, the flexible fabric perform is delivered to a tower assembly area. The fiber tow is woven in the mandrel circumference.

Description

Composite wind turbine tower and its manufacturing method {A COMPOSITE WIND TURBINE TOWER AND A METHOD FOR FABRICATING SAME}

The present invention relates to a wind turbine tower, and more particularly to a composite wind turbine tower and a method of manufacturing the same.

Known wind turbines include a rotor with a plurality of blades. The rotor is installed in a housing or nacelle located on top of the truss or tubular tower. The rotor blades convert wind energy into rotational energy or torque, which drives one or more generators that are, but not always, rotatably coupled to the rotor through a gearbox. If a gear box is used, the gear box increases the original low rotational speed of the turbine rotor for the generator so that mechanical energy can be efficiently converted into electrical energy. In other cases, low speed generators are used to generate power without the use of gearboxes.

At least some known wind turbines use large blades (eg, 50 meters or more in length) to increase power production and reduce energy costs of wind turbines. The large blade size leads to an increase in the power rate of the turbine and an improvement in the energy production efficiency. However, the construction of large wind turbine towers is limited by the horizontal size of the tower base, the need for thicker (heavy) plates, and the increased manufacturing cost. Currently, the most well known turbine tower is a welded tubular plate steel structure. This plate steel structure usually increases the material cost by using a large amount of steel. In addition, large tubular towers require special fabrication equipment and can be cumbersome and difficult to transport from the mill to the turbine assembly.

It is an object of the present invention to provide a combined wind turbine tower and a method of manufacturing the same that can increase the power production of wind turbines and reduce energy costs.

According to one aspect, the present invention provides a method of manufacturing a tower or part thereof for use in a wind turbine. The method includes the steps of: weaving a fibrous tow into a shape corresponding to the shape of the tower or part thereof to form a flexible fabric preform; Laminating the flexible fabric preform to form a composite shell or fragment thereof.

In another aspect, the present invention provides a wind turbine assembly having a composite wind turbine tower and a wind turbine coupled to the tower. The tower includes a first fabric composite layer, a second fabric composite layer, and a layer of core material. The tower has a tensile modulus of about 5 GPa to about 300 GPa.

It is an object of the present invention to provide a combined wind turbine tower and a method of manufacturing the same that can increase the power production of wind turbines and reduce energy costs.

1 is a perspective view of an exemplary wind turbine,

2 is a cross-sectional view of an exemplary multilayer composite shell that may be used in the wind turbine shown in FIG. 1, FIG.

3 is a cross-sectional view of an exemplary single layer composite shell that may be used in the wind turbine shown in FIG. 1, FIG.

4 is a cross-sectional view of an exemplary single layer polygonal composite shell that may be used in the wind turbine shown in FIG. 1, FIG.

5 is a cross-sectional view of an exemplary monolayer flexible fabric preform on a mandrel,

6 is a cross-sectional view of the flexible fabric preform shown in FIG. 5 and laid flat;

FIG. 7 is a cross sectional view of the flexible fabric preform shown in FIG. 6 and in a bent or “folded” configuration; FIG.

8 is a side view of a folded flexible fabric preform loaded on a loading trolley with the trolley arm lowered;

9 is a view of a folded flexible fabric preform loaded on a loading trolley with the trolley arm raised;

10 is a side cross-sectional view of a truck trailer with a flexible fabric preform loaded on a roller trolley in a track installed on the opposite side of the trailer's trailer interior;

11 is a cross-sectional view of a truck trailer in which a flexible fabric preform is formed in a truck trailer when the flexible fabric preform is made and then loaded onto a roller trolley in a track installed on the opposite side of the truck trailer;

12 is an enlarged view of an exemplary triaxial braid;

13 is an enlarged view of a portion of an exemplary three-dimensional layer of a fabric composite.

<Brief description of symbols for the main parts of the drawings>

10: wind turbine assembly 12: tower

14 support surface 16 nacelle

18: rotor 20: hub

22: rotor blade 24: centerline

26: composite cell 28: single fabric composite layer

30: inner fabric composite layer 32: core material

34: Single Layer Composite Cell 36: Flexible Fabric Preform

38: mandrel 40: container or trailer

42: shipping trolley 44: trolley arm

46: roller trolley 48: track

50: braiding machine 52: fiber tow

54: Opposite Top 56: Arrow

58: loading rail

1 is a perspective view of an exemplary wind turbine assembly 10. In this exemplary embodiment, the wind turbine assembly 10 is a horizontal axis wind turbine. Alternatively, the wind turbine assembly 10 is a vertical axis wind turbine. In an exemplary embodiment, the wind turbine assembly 10 includes a tower 12 extending from the support surface 14, a nacelle 16 installed on the tower 12, and a rotor 18 coupled to the nacelle 16. It includes. The rotor 18 includes a rotatable hub 20 and a plurality of wind turbines or rotor blades 22 coupled to the hub 20. In the exemplary embodiment, the rotor 18 includes three rotor blades 22. In an alternate embodiment, the rotor 18 includes about three rotor blades 22. The centerline 24 extends through the nacelle 16 and the hub 20. Each rotor blade 22 includes a tip 26. In an exemplary embodiment, the tower 12 is a composite tower made of carbon fiber, glass fiber, or any other suitable material capable of performing the functions as described herein, the support surface 14 and the nacelle. It may include a cavity (not shown in FIG. 1) extending between the 16. The height of the tower 12 is selected according to factors and conditions known in the art. The blade 22 is deployed about the rotor hub 20 to facilitate the rotary rotor 18 converting the kinetic energy of the wind into usable mechanical energy and subsequently to electrical energy.

2-4 show exemplary cross-sectional shapes of the tower 12. In an exemplary embodiment, tower 12 includes composite shells 26 and 34, which may be fabricated using one or more layers of fabric composites 28 and 30, wherein the one or more layers of fabric composites are not limited to epoxy. And resins (not shown) such as vinyl esters, polyester resins, phenolic resins, polypropylene or composites thereof. As used herein, “fabric composites” include, but are not limited to, metals, plastics, wood, and / or fibers, such as, but not limited to, glass fibers, carbon fibers, and / or aramid fibers, etc. as described herein. Refers to a composite formed by weaving together one or more suitable material (s). Composite shell 26 may also include other component layers laminated to one or more layers of fabric composite layers 28 and 30. For example, as shown in FIG. 2, composite shell 26 is an outer fabric composite layer that facilitates reinforcement of composite shell 26 and / or tower 12 to prevent bending due to wind or working load. It may be a multi-layer composite shell comprising a core material 32 disposed between 28 and the inner fabric composite layer 30.

FIG. 2 shows a multilayer composite shell 26 comprising a core material 32 between three layers, namely the outer fabric composite layer 28, the inner fabric composite layer 30 and the composite layers 28, 30. However, composite shell 26 may comprise any combination of layers including any number of fabric composite layers, such as layers 28 and 30, and / or core material layers, such as core material 32. . For example, only one layer of core material 32 is shown in FIG. 2, and the core material 32 is shown sandwiched between two adjacent fabric composite layers 28, 30. Multilayer composite shells, such as 26, may include any number of layers of core material 32 to enable them to function as described herein.

For example, in an alternative embodiment, the composite shell may be a single layer composite shell 34 as shown in FIGS. 3 and 4. In this exemplary embodiment, the composite shell 34 may include a single fabric composite layer 28 or 30 without the core material 32.

In one embodiment, the method of making wind turbine tower 12 is a flexible fabric preform formed by weaving a fibrous tow around a mandrel 38 having a shape corresponding to the desired shape of the composite shell. forming a preform). The flexible fabric preform is a precursor of the composite shell and thus usually has the same configuration as the composite shell. For example, the flexible fabric preform may comprise a single layer of material (eg, a fabric composite), such as the flexible fabric preform 36 shown in FIG. 5, alternatively depending upon the desired configuration of the composite shell. It may include more than one layer of material (not shown). The flexible fabric preform is then transported to the tower assembly where it is laminated to form a composite shell. The composite shell may be used alone as a composite wind turbine tower or as part of a composite wind turbine tower.

Alternatively, the flexible fabric preform may be a precursor to only a portion of the composite shell. For example, the flexible fabric preform may be in the form of a panel that may correspond to the lower, middle and / or upper sections of the composite shell or may form one or more sides (sides) of the composite shell through lamination. For example, in one embodiment the flexible fabric preform corresponds to one side of the polygonal composite shell as shown in FIG. When the flexible fabric preform corresponds to one section of the composite shell, the preform can be formed by weaving fiber tow around a mandrel of a shape corresponding to the shape of the section of the composite shell being formed. Alternatively, the preform may be formed without the use of a mandrel by weaving the fiber tow in a relatively flat form, such as in the form of a panel that may form the side or part of the side of the composite shell. Once laminated, the sections can be assembled to form a composite shell.

As noted above, in an exemplary embodiment the flexible fabric preform may be formed by weaving fiber tow around the mandrel 38 to form, for example, a fabric composite. The term "fiber tow" as used herein refers to a bundle of filaments of material (s) that are woven around the mandrel to form a fabric composite. Materials used to form the fiber tow include, but are not limited to, fabric composites including metal, plastic, wood and / or fibers such as, but not limited to, glass fibers, carbon fibers, aramid fibers or combinations thereof, and the like. And / or any suitable material used to form 30). Specific examples of suitable carbon fibers include T300 carbon fibers, AS2C carbon fibers, AS4 carbon fibers, AS4C carbon fibers, AS4D carbon fibers, AS7 carbon fibers, IM9 carbon fibers, and the like. In one embodiment, the carbon fiber is T300 carbon fiber. Other examples of suitable materials that can be used for the fiber tow include silicon carbide fibers such as Kevler®49, SCS-6, S2 glass, E-glass, Nicalon ™ fibers (available from Nippon Carbon Company), alumina, and combinations thereof. . Typically, the fiber tow will have a size of about 1,000 to 80,000, more typically about 12,000 to 80,000 (ie, a bundle comprising about 12,000 to 80,000 filaments).

The specific mechanism for weaving the fiber tow is not particularly limited, but usually depends on the endurance design load of the composite shell of the specific shape. The tow is preferably woven such that the fabric composite (and flexible fabric preform) remains substantially in shape (ie, does not loosen) upon removal from the mandrel 38. Typically, the fabric is achieved by twisting the tow biaxially or triaxially. An exemplary diagram of a three axis braid structure is shown in FIG. 12. The tow may be further twisted into a planar and / or solid layer depending on the desired properties of the tower 12. Suitable braiding machines are known in the art and are commercially available.

13 illustrates a portion of an exemplary three-dimensional layer of a woven composite. The three-dimensional layer of the fabric composite will typically comprise regions of interweaving pattern and / or longitudinal direction (L) (i.e., directions corresponding to the height of the tower or composite shell formed from the fabric composite) that vary constantly or uniformly. . The mutual weave pattern and / or size of the three-dimensional layer of the woven composite can vary along the longitudinal direction (L) as a function of height. For example, the three-dimensional layer of the fabric composite may be the size and / or mutual weave of the portion of the fabric composite that is (part of) the bottom (base) section of the composite shell rather than the portion of the layer that is (part of) the upper section of the composite shell. The pattern may be different. Typically, the three-dimensional layer of the fabric composite will include a consistently repeating mutual weave pattern of a constant depth D with respect to the perimeter or perimeter of the fabric composite of a given height along the longitudinal direction (L).

As noted above, in an exemplary embodiment the flexible fabric preform is a precursor of the composite shell and will thus typically have the same layer configuration as the composite shell. For example, as shown in FIGS. 3 and 4, in embodiments where the composite shell 34 comprises only a single layer, such as a single fabric composite, the flexible fabric preform is only a single layer of fabric composite formed from woven tow. Will include. In the embodiment where the composite shell 26 includes multiple layers as shown in FIG. 2, the flexible fabric preform will include a layer (s) of multiple and / or core materials of the textile composite formed from woven tow.

When the flexible fabric preform contains only a single layer of fabric composite, it is preferred that the layer is a three-dimensional layer, as shown in FIG. Typically, in such embodiments, the layer will have a thickness of at least 2 mm, more typically about 3 mm to 10 mm. In this embodiment, the composite shell 34 formed from the flexible fabric preform will typically contain only a single layer of fabric composite, not including the core material.

In another embodiment, the flexible fabric preform comprises a plurality of layers. For example, the flexible fabric preform may comprise at least two layers of fabric composites. Such multiple layers of preforms may be formed by weaving a first inner layer around the mandrel. The second layer can then be woven around the first inner layer to form a plurality of preforms. It should be understood that additional layers can be selectively woven around the second layer to form a preform consisting of multiple layers of fabric composite. In some embodiments, the layers making up the preform may be held together by sealing the ends of the layers together. Such closure helps to prevent the layers from sliding or separating during transportation to the tower assembly. The layers of the plurality of layers of preforms may be planar or three-dimensional. In one embodiment, the plurality of preforms includes two or more planar layers. The thickness of each layer in the multi-layer preform fabric composite may be the same or different from other layers of the preform, but typically each layer of the fabric composite has a thickness of at least about 2 mm, more typically about 3 mm to 10 mm. Preferably, the layers of the woven composite of multiple layers of preforms have a thickness of about 6 mm to 8 mm.

In some embodiments, the multiple layers of preforms comprise one or more layers of core material. The core material may be located between one or more layers of the fabric composite. The core material is typically a solid, lightweight, hard or semi-hard material that supports a layer of fabric composite in the composite shell. Suitable core materials used in the formation of composite shells include, but are not limited to, balsa wood, polyvinyl chloride (PVC) foam, styrene acrylic nitrate (SAN) foam, polyethylene (PE) foam, aluminum honeycomb, but not limited to metal honeycombs such as honeycomb, but not limited to fabrics such as polyester core mats and combinations thereof. The layer (s) of the core material present in the flexible fabric preform may have any suitable thickness that enables the core material to perform the functions as described herein. For example, in one embodiment, the core material layer typically has a thickness of about 5 mm to 100 mm.

One or more layers of core material may be positioned between one or more layers of fabric composites in any desired orientation or configuration to form multiple layers of flexible fabric preforms. For example, in one embodiment, the flexible fabric preform may comprise a first inner fabric composite layer, a second outer fabric composite layer, and at least one core layer positioned between the inner and outer layers of the fabric composite. Can be. The cross-sectional shape of the composite shell formed from this flexible fabric preform is shown in FIG. Such preforms may be formed by weaving a first layer around the mandrel to form a first inner fabric composite layer. Thereafter, one or more layers of core material may be disposed around the first inner layer. The core material may be held in place around the first inner layer using any suitable mechanism. For example, in one embodiment the core material may be sealed to the first inner layer. Alternatively or in addition to the sutures, the core material may be retained around the first inner fabric composite layer using adhesives and / or other binders.

As noted above, the core material is usually a solid hard or semi-hard material. Such rigidity is beneficial in being supported by composite shells, but by incorporating such materials into the preform structure, the overall flexibility of the flexible fabric preform can be reduced. As a result, the preform may be difficult to bend and / or bend, depending on the hardness of the core material. This may be a problem, especially when transporting the preform, where it may be desirable to fold and / or bend the preform. Thus, in some embodiments each layer of the core material of the preform may comprise a plurality of discrete core material pieces. Typically, adjacent pieces of core material are sufficiently spaced apart from one another so that the preforms can be bent or bent along the space between the core material pieces, thereby improving the flexibility of the flexible fabric preform. Forming the core material layer with a plurality of discrete core material pieces rather than a single continuous core material piece may increase the flexibility of the final flexible fabric preform, which is a space formed between adjacent core material pieces. This is because it can be bent or bent along. Each of the core material pieces of the core material layer can be positioned adjacent to the first inner layer of the fabric composite using any suitable mechanism. Moreover, the number of core material pieces used in the core material layer is not critical, but rather will depend on the degree of flexibility desired for the flexible fabric preform.

Once the core material layer is positioned adjacent the first inner fabric composite layer, the second outer fabric composite layer can be woven around the core material to form a flexible fabric preform. This kind of preform can be used to form a composite shell as shown in FIG. The multi-layered flexible fabric preform of the present invention is not limited to a three-dimensional structure, but may alternatively further comprise one or more layers of additional fabric composite and / or core material incorporated into the preform in any suitable layer configuration. . For example, in one embodiment at least one additional fabric composite layer is woven around the first inner fabric composite layer, and a core material layer is positioned around at least one additional fabric composite layer. In another embodiment, at least one additional fabric composite layer is woven around the second layer of the fabric composite. In further embodiments, at least one layer of core material is positioned adjacent to the first layer of core material, and a second outer layer of fabric composite is woven around the outer layer of the core material to form a plurality of flexible fabric preforms. . In another embodiment, a second layer of core material is positioned adjacent to a second layer of fabric composite, and a third layer of fabric composite is woven around the second layer of core material to form a flexible fabric preform. Other suitable layer configurations are also available.

After the flexible fabric preform has been formed, the flexible fabric preform can be transported to the tower assembly to form a composite shell. In one embodiment, the flexible fabric preform can be removed from the mandrel prior to transport. Since the preform is flexible, once removed from the mandrel, it is easily folded, bent, superimposed or otherwise manipulated to facilitate transportation to the tower assembly. In this embodiment, upon arrival at the tower assembly, the flexible fabric preform is laminated while slipping over the mandrel as described below to form a composite shell.

In an alternative embodiment, the flexible fabric preform is formed around the inflatable mandrel. Before transporting the flexible fabric preform to the tower assembly, the mandrel is retracted without removing the preform from the mandrel. By shrinking the mandrel, the preform can be easily manipulated and transported. Once reached, the mandrel re-expands and the flexible fabric preform is laminated to form a composite shell as described below.

Delivery of the flexible fabric preform to the tower assembly is shown in FIGS. 5-11. In particular, FIG. 5 is a cross-sectional view of flexible fabric preform 36 that may be used to form a circular tower and include a single layer of material, such as a fabric composite that is woven around mandrel 38. The flexible fabric preform 36 may be represented by a reference point 1-8 that represents an exemplary fold of the preform 36. The flexible fabric preform 36, once removed from the mandrel 38, may be folded and laid flat. 6 is a cross-sectional view of an exemplary flexible fabric preform 36 lying flat. As shown in FIG. 6, in an exemplary embodiment, reference point 8 is aligned with reference point 6, reference point 1 is aligned with reference point 5, reference point 2 is aligned with reference point 4, and reference points 3 and 7 are folded flexible fabric preforms 36. To form an end. The folded flexible fabric preform 36 may be bent into any suitable configuration before being shipped to the tower assembly. 7 illustrates a cross-sectional view of flexible fabric preform 36 bent in an exemplary configuration.

The flexible fabric preform 36 may be transported to the tower assembly, for example by truck, ship, railroad, or the like. The flexible fabric preform 36 may be carried in a truck's shipping container or trailer 40 for transportation to a tower assembly. In one embodiment, the flexible fabric preform 36 is transported into a shipping container or truck trailer 40 using a shipping trolley 42 as shown in FIGS. 8-9. In particular, as shown in FIG. 8, the flexible fabric preform 36 is disposed above the series of individual shipping trolleys 42 when the trolley arm 44 is lowered. When placed over shipping trolley 42, flexible fabric preform 36 may be folded and unfolded as shown in FIG. 6, or bent to any suitable configuration as shown in FIG. In one embodiment, trolley arm 44 is simultaneously in a vertical position using a controlled hydraulic actuator such that each shipping trolley 42 supports a portion of flexible fabric preform 36 as shown in FIG. Is rotated. Alternatively, trolley arm 44 may be raised using motorized telescopic bracing (not shown). The shipping trolley 42 supporting the flexible fabric preform 36 may be moved into a shipping container or truck trailer 40 for transportation to the tower assembly of the flexible fabric preform 36. As shown in FIG. 9, the portions of the flexible fabric preform 36 spanned between two adjacent shipping trolleys 42 are separated from each other for loading trolley 42 to be loaded into a shipping container or truck trailer 40. As it moves closer, it becomes bent. The number of shipping trolleys 42 used to carry the flexible fabric preform 36 is not limited, but the bent height H of the flexible fabric preform 36 is generally the standard for shipping containers or truck trailers 40. Sufficient number of trolleys are used so as not to exceed the height. For example, in one embodiment, twelve to fourteen trolleys 42 are used. In another embodiment, thirteen trolleys 42 are used. Each shipping trolley 42 may support the weight of the flexible fabric preform 36 of about 1 to 3 tons depending on the shape and wall thickness variation of the flexible fabric preform 36.

Alternatively, jibs or bridge cranes and folded lift beams (not shown) may be used for placement of the flexible fabric preform 36 into the shipping trolley 42. For example, when the folded lift beam lifts the end of the flexible fabric preform 36, a vertical shipping trolley 42 is positioned below the lift beam. The flexible fabric preform 36 is then delivered to the shipping trolley 42 when the beam is lowered. This process is repeated for the remaining shipping trolleys 42. By using this process, the flexible fabric preform 36 can be bent during each lift cycle, eliminating the need for trolley hydraulics or motorized telescopic bracing.

In another embodiment, the flexible fabric preform 36 is installed along the track in a track 48 that is installed on either side of the upper portion 54 of the interior of the shipping container or truck trailer 40 as shown in FIG. 10. It can be supported by the equivalent roller trolley 46 of. In one embodiment, the folded or bent flexible fabric preform 36 is placed across the loading rail 58 and the roller trolley 46, for example using a crane or other suitable mechanism. The roller trolley 46 is then mounted to the track 48 within the shipping container or truck trailer 40. Alternatively, the roller trolley 46 may be pre-mounted on the track 48 in the shipping container or truck trailer 40, and the flexible fabric preform 36 is pre-mounted on the track 48. The flexible fabric preform 36 can be loaded into the truck trailer 40 by rolling it in the direction indicated by arrow 56 shown in FIG. The portion of flexible fabric preform 36 placed between adjacent roller trolleys 46 is bent as the roller trolleys 46 move closer together. The loading rail 58 is removed before transportation.

In an alternative embodiment, flexible fabric preform 36 may be formed when loaded into shipping container or truck trailer 40 as shown in FIG. In this embodiment, the braiding machine 50 may be placed inside the shipping container or truck trailer 40 or just outside the shipping container or truck trailer 40 (not shown) as shown in FIG. 11. The fiber tow 52 is fed to the braiding machine 50 where it is wound on a removable mandrel (not shown) to form the flexible fabric preform 36. In this embodiment, the removable mandrel will typically be shorter than the length of the flexible fabric preform 36. Thus, for the formation of a flexible fabric preform 36 that is longer than the length of the removable mandrel, the portion of the formed flexible fabric preform 36 leaves one end of the removable mandrel so that the other end of the removable mandrel is exposed. Thus, the fiber tow 52 can continue to be woven around the exposed end of the movable mandrel. This process can continue until a flexible fabric preform 36 of the desired length is obtained. In this embodiment, as the formed end of the flexible fabric preform is removed from the movable mandrel, it may be supported by a roller trolley 46 or a shipping trolley (not shown).

The flexible fabric preform 36, once loaded in a shipping container or truck trailer 40, can be transported to a tower assembly to form a composite shell. The flexible fabric preforms 36 arriving at the assembly place are loaded from the shipping container or truck trailer 40 and slip-shifted to the second mandrel and then laminated as described below to form a composite shell. Alternatively, in embodiments using inflatable mandrel, flexible fabric preform 36 is loaded from shipping container or truck trailer 40, and after the mandrel is re-expanded, flexible fabric preform 36 This is laminated to form a composite shell.

When the flexible fabric preform 36 slips to the second mandrel or the expandable mandrel is re-expanded, the flexible fabric preform 36 is injected with resin or resin is applied to the flexible fabric preform 36, The flexible fabric preform 36 is laminated to join the layers or layers of the preform 36 together to form the composite shell of the tower 12. Although not limited, the resin transfer molding (RTM) process, the resin film injection (RFI) process, the vacuum assisted resin transfer molding (VARTM) process, the heating of the resin injection preform for a suitable time at a predetermined temperature and / or resin injection Any suitable laminating process may be used, such as applying pressure to the preform. In some embodiments, the resin is injected into the preform 36 using pressure, heat and / or vacuum bag systems as used in the resin transfer molding process. Moreover, in some embodiments, the woven preform layer and / or the core material layer in the preform 36 are coded with resin prior to weaving and / or placement on the mandrel. The resin used for laminating the preform 36 may include any thermosetting or thermoplastic resin, including, for example, polyester, phenolic resin, polypropylene, vinyl esters, epoxy, other similar resins or combinations thereof. In one embodiment, the resin is applied to the preform 36 in an amount of about 45% to 48% by volume ratio of the composite shell prior to laminating.

After lamination, the composite shell can be removed from the mandrel using any suitable technique. For example, the mandrel may be coated with a release film to easily remove the composite shell from the mandrel before slipping the flexible fabric preform onto the mandrel. Non-limiting examples of release films include various water soluble polymer / wax emulsions. In another embodiment, if the mandrel is an inflatable mandrel, the mandrel may be retracted and the composite shell may be removed from the retracted mandrel. In another embodiment, the mandrel can be left in the composite shell after lamination, to be part of the completed composite wind turbine tower.

As noted above, in some embodiments, the flexible fabric preform is a precursor of one section of the composite shell. In such an embodiment, the flexible fabric preform precursor section delivered to the tower assembly is laminated using any suitable technique, and the laminated piece is then assembled to form a composite shell.

Composite shells formed using the methods described herein can be used to form composite wind turbine towers. The composite wind turbine tower described herein can be used to support wind turbines of any size, including, for example, GE Energy's 4-7 MW design. Composite wind turbine towers preferably have strength characteristics comparable to steel towers. For example, in some embodiments, the composite wind tower of the present invention preferably has a yield strength in the range of about 70 MPa to 900 MPa. The actual strength of such towers may vary depending on the wall thickness, fiber content, fiber orientation, and material of the fiber. Overall, composite wind turbine towers still have good strength but are lighter than conventional steel towers. For example, a composite wind turbine tower produced using the method described herein may have a very low weight tower weight and a tensile modulus of about 5 GPa to 300 GPa, more preferably about 20 GPa to 200 GPa. The improved tensile modulus of the combined wind turbine tower also increases the frequency range of the tower to allow less swing under varying turbine operating and wind loads. Typically, the first natural frequency of the combined wind turbine tower is about 0.1 Hz to 2 Hz, more preferably about 0.2 Hz to 0.6 Hz.

The wall thickness of the composite shell will vary depending on the material used to form the composite shell. In one embodiment, the composite shell is formed of a single layer of flexible fabric preform and has a wall thickness of at least about 10 mm, more preferably at least about 20 mm. In another embodiment, the composite shell is formed of a multilayer flexible fabric preform and has a wall thickness of at least about 20 mm, more preferably about 20 mm to about 150 mm. The wall thickness of the composite shell may vary within a single composite shell. For example, the bottom end of the composite shell that forms the base of the composite tower will typically be thicker than the top end of the composite shell. The composite shell may have any suitable form. In one exemplary embodiment, the composite shell is generally conical and has a circular cross-sectional profile as shown in FIGS. 2 and 3. In another embodiment, the composite shell has a polygonal cross-sectional profile as shown in FIG. The exact size of the composite shell is not critical to the description of the present invention. Typically, however, the composite shell has a diameter of about 2 m to about 20 m, more preferably about 3.5 m to 5 m, and an upper diameter of about 2 m to about 6 m, more preferably about 2.5 m to about 3.5 m. Can be. In one exemplary embodiment, the composite shell may have a length (height) of about 10 m to about 150 m, more preferably about 80 m to about 100 m. The weight of the composite shell formed using the method described herein will vary depending on the size and material of the composite shell used to form the flexible fabric preform, but typically from about 40 metric to about 500 metric tons, more preferably About 50 to 90 metric tons. The weight of the flexible fabric preform prior to laminating may be from about 30 metric to 320 metric tons, more preferably from about 30 metric to about 70 metric tons.

In another aspect, the present invention also provides a wind turbine assembly as shown in FIG. 1. The wind turbine assembly includes a wind turbine and a composite wind turbine tower comprising a composite shell as described herein. The wind turbine is coupled to the tower to form a wind turbine assembly.

By using the wind turbine tower and the wind turbine tower manufacturing method signed therein, it is possible to produce a wind turbine tower that can be easily assembled at the tower installation and assembly station. Moreover, as noted above, by fabricating wind turbine towers in this manner, the tower can be manufactured more efficiently and at lower cost than conventional wind turbine towers that require a large amount of steel and have expensive materials and manufacturing costs. In addition, the fabrication of complex wind turbine towers via transport of flexible fabric preforms to tower assemblies and on-site preform laminating is easy and more cost effective than the transport of prefabricated towers. In some embodiments, the wind turbine towers described herein eliminate the need for intermediate flange contacts, inspection of installation and life, maintenance costs typically associated with steel towers. In addition, there is no need for separate painting, repainting or modification of the turbine operating life as well as the associated costs normally required for steel towers.

Exemplary embodiments of the wind turbine tower and the manufacturing method of the wind turbine tower have been described in detail. These wind turbine towers and their fabrication methods are not limited to the specific embodiments described above, but rather the components of the wind turbine tower can be utilized independently of the other components described above. For example, the wind turbine tower described above and its manufacturing method may have other industrial or consumer applications, and are not limited to the use of the aforementioned application. Rather, the invention may be practiced and utilized in connection with a variety of other products and in other environments.

Although the present invention has been described with reference to specific embodiments, those skilled in the art will recognize that the present invention can be practiced by modification within the spirit and scope of the claims.

Claims (10)

In the manufacturing method of the tower 12 or its components used for the wind turbine 10, Weaving the fiber tow 52 into a shape corresponding to the shape of the tower or its components to form a flexible fabric preform 36; Laminating the flexible fabric preform to form a composite shell 26, 34 or a section thereof. Method for manufacturing towers or parts thereof used in wind turbines. The method of claim 1, Carrying the flexible fabric preform 36 to a tower assembly position prior to laminating; Method for manufacturing towers or parts thereof used in wind turbines. The method of claim 1, The fiber tow 52 is woven around the mandrel 38 Method for manufacturing towers or parts thereof used in wind turbines. The method of claim 3, wherein The mandrel 38 is a first mandrel, and the method Removing the flexible fabric preform 36 from the first mandrel before transportation; Slip moving the flexible fabric preform to a second mandrel prior to laminating Method for manufacturing towers or parts thereof used in wind turbines. The method of claim 4, wherein Injecting a resin into the flexible fabric preform 36 prior to laminating; Method for manufacturing towers or parts thereof used in wind turbines. The method of claim 3, wherein Weaving the fiber tow 52 around the mandrel 38 to form a first layer of fabric composite 28, and weaving the fiber tow around a first layer of the fabric composite to fabric a second layer of fabric. Further comprising forming the composite material 30 Method for manufacturing towers or parts thereof used in wind turbines. The method of claim 3, wherein Weaving the fiber tow 52 around the mandrel 38 to form a fabric composite 28 of the first layer, disposing a layer of core material 32 adjacent to the fabric composite of the first layer, Weaving the fiber tow around the core material layer to form a second layer of fabric composite 30. Method for manufacturing towers or parts thereof used in wind turbines. The method of claim 7, wherein The core material 32 may be formed of a material selected from the group consisting of balsa wood, polyvinyl chloride foam, styrene acryl nitrate foam, polyethylene foam, and combinations thereof. Containing Method for manufacturing towers or parts thereof used in wind turbines. The method of claim 1, The flexible fabric preform 36 is laminated using a process selected from the group consisting of resin transfer molding and vacuum assisted resin transfer molding. Method for manufacturing towers or parts thereof used in wind turbines. The method of claim 1, The fiber tow 52 comprises glass fibers, carbon fibers, aramid fibers or a combination thereof. Method for manufacturing towers or parts thereof used in wind turbines.