Patent Application
20250020099
The present invention relates to a tip system for a wind turbine blade, and associated methods of manufacture and assembly.
To improve adaptability and manufacturability of wind turbine blades, blades can be provided in modular form, having for example a separate tip section from a mainboard and/or root section.
It is an object of the invention to provide improved designs of modular wind turbine blade designs.
The invention relates to a method of manufacturing a wind turbine blade by joining a tip section of the blade and a mainboard section of the blade at a joining section, wherein
The present manufacturing method forms a robust and durable joint between the mainboard and tip sections of a modular wind turbine blade. The method introduces no extra loads or stresses in the load carrying structure, whereby the method provides a blade of a durability and quality equaling a common non-modular wind turbine blade. Further, the method provides the opportunity to shape the layup such that the intended aerodynamic surface may be achieved and a smooth transition from the tip section to the mainboard section may be achieved.
In an embodiment of the invention the method further comprising the steps of
It may be beneficial to also join the mainboard- and tip sections at the leading edge and trailing edge of the blade using scarf joints in the local laminates to provide an advantageous structurally integrated wind turbine blade.
In some embodiments it may be advantageous to have fibres from the principal load carrying laminates and/or from the leading edge- and trailing edge laminates of the tip section and mainboard section respectively protruding into the recesses and into the layups, whereby particularly strong integration of the lay ups with the mainboard- and tip sections may be achieved.
For example, parts of fibre plies comprised in the principal load carrying laminate of the mainboard section may protrude at the taper section and into the air in the recess. These protruding fibre material can then be firmly integrated to a dry fibre layup, becoming an integral part of the layup, and after infusion with resin, a particularly strong connection may be formed. Of course such protruding fibre material may be provided in all tapering sections, partly pre-filling the recess.
According to further embodiments of the invention the first layup, and optionally the second layup and the third layup, is/are selected from the group consisting of a fibre material, a resin, a pre-formed part, an adhesive, a pre-preg material, a pre-cured element or any combination thereof.
The layup material for attachment to the recesses in the laminate(s) of the tip section and of the mainboard section may be varied for different reasons, including price, production speed, ease of handling and complexity of arranging such layups.
In an embodiment of the invention step d) comprises arranging a pre-formed circumferentially extending shell attachment element in the first recess and the second recess, optionally said shell attachment element extending to the first leading edge recess and/or the second leading edge recess, the first trailing edge recess and/or the second trailing edge recess, said shell attachment element comprising the first layup and, optionally, the second and/or third layups.
It may be beneficial to have one or more layups comprised in a preformed part. According to this embodiment, the preformed part may be arranged to attached to the recesses by gluing. The joint may be further strengthened, for example, by overlaminating, so that at least the principal main laminates of the tip- and mainboard sections, that is, the first principal main laminate and the second principal main laminate, and optionally also the leading edge laminates of the tip- and mainboard sections as well as the trailing edge laminates of the tip- and mainboard sections, are overlaminated at predesigned positions in the shell attachment element. Further, the overlamination may form the outer surface of the blade and thus provide a smooth aerodynamic surface.
In an embodiment of the invention said first recess, said second recess, said first leading edge recess, said second leading edge recess, said first trailing edge recess and said second trailing edge recess overlap to form a single recess around the circumference of the tip section and the mainboard section.
It may be advantageous to arrange one or more layups around the whole circumference of the two sections, respectively, to achieve a substantially continuous scarf joint around the circumference of the wind turbine blade.
In further embodiments of the invention the joining step e), and optionally steps e1) and e2), comprise
A very versatile and advantageous embodiment is achieved when joining the tip section with the motherboard section using fibre material very similar or substantially identical to the fibre material already comprised in the principal load carrying laminates.
The fibre material may be a pre-preg material which is cured, e.g. by heating, after arranging one or more layers in the recesses. The fibre material may also be plies of dry fibre, which, after arranging them in the recesses, are infused with resin and cured. When a vacuum assisted infusion process is used in these embodiments, a particularly advantageous embodiment has been achieved.
It is also possible to combine pre-preg material with dry fibre material in the recesses.
According to embodiments of the invention the joining step e), and optionally steps e1) and e2), comprise
It may be advantageous to use pre-formed parts glued into the recesses. This may be comparatively easy to handle. Furthermore, the quality of the pre-formed part may be assessed prior to arranging them in the recesses, making this option advantageous with respect to quality control.
It may also be possible to glue pre-formed parts into the recesses, still leaving some space for overlamination with dry fibre and resin and/or pre-preg material.
In an embodiment of the invention said first layup comprises a pre-formed part, said pre-formed part having an outer surface corresponding to a desired aerodynamic profile at the joining section.
It may be possible to pre-form a part with a desired surface geometry. Especially the outer surface may advantageously have a shape seamlessly integrating with the desired aerodynamic profile of the wind turbine blade. In this way, less skill from the worker is required to achieve the correct profile.
According to embodiments of the invention the joining section has a length of 1-5 m in the longitudinal direction. To obtain a strong enough joint between the tip section and the mainboard section, the joining section may need to have a minimum length.
According to embodiments of the invention the width of the joining section is between 0.5 m and the total width of the blade from a leading edge to a trailing edge.
According to further embodiments of the invention the taper has a depth to length ratio of between 1 to 30 and 1 to 2.
According to an embodiment of the invention the ratio of the length of the tip section to the length of the mainboard section is between 1 to 8 and 1 to 1, preferably between 1 to 4 and 1 to 2.
The invention also relates to a wind turbine blade formed by joining a tip section and a mainboard section at a joining section, said joining section comprising a scarf joint bonding together a first load-carrying principal laminate integrated in a first aerodynamic shell of said tip section and a second aerodynamic shell with a second load-carrying principal laminate integrated in the second aerodynamic shell of said mainboard section.
According to the invention, a wind turbine blade with properties corresponding to a non-modular blade is obtained, with little or no additional weight, due to the integration of the joining section in the laminates, all additional components having a density similar to that of typical laminates.
The invention further relates to a tip section for a wind turbine blade, the tip section comprises a first aerodynamic shell with a first load-carrying principal laminate integrated in the first aerodynamic shell, said first load-carrying principal laminate including a first recess at a first end of the tip section, the first recess comprising a first taper section where a thickness of the first load-carrying principal laminate is tapered in thickness towards the first end of the tip section.
According to the invention a tip section is provided that can be used to be connected to a mainboard section to produce a wind turbine blade. It may be possible to use such a tip section for different wind turbine blades of different lengths, provided that the geometry at the joining section allows for it. It may thus be possible to provide a tip section that can be attached to mainboard sections of different lengths and thus providing a convenient way to produce different blades using the same tip section.
The invention also relates to a mainboard section for a wind turbine blade, the mainboard section comprising a second aerodynamic shell with a second load-carrying principal laminate integrated in the second aerodynamic shell, said second load-carrying principal laminate including a second recess at a second end of the mainboard section, the second recess comprising a second taper section where a thickness of the second load-carrying principal laminate is tapered in thickness towards the second end of the mainboard section.
The invention further relates to a kit for manufacturing a wind turbine blade, said kit comprising a tip section as described herein and a mainboard section as described herein. The kit of parts may further comprise layup or inserts for arrangement in the recesses of the tip section and mainboard section and for forming the aforementioned scarf joints.
Accordingly, there is provided a method of manufacture of a tip section for a wind turbine blade, comprising:
Preferably, said core member comprise a cross-sectional profile substantially corresponding to a portion of a desired aerodynamic profile of a tip section for a wind turbine blade.
Preferably, the tip section comprises at least a leading edge core member and a trailing edge core member. Further preferably, the tip section further comprises a main laminate core member to be arranged between the leading edge core member and a trailing edge core member.
In one aspect, at least one of the core members is substantially hollow.
Preferably, at least one of the core members comprises a hollow braided infused core, preferably comprising glass fibre, carbon fibre, and/or a hybrid thereof.
Preferably, at least one of the core members comprises at least one pultruded reinforcement member. Preferably, said at least one pultruded reinforcement member comprises a leading edge reinforcement profile, a trailing edge reinforcement profile, and/or a main laminate reinforcement profile.
In an additional or alternative aspect, at least one of the core members is provided as a substantially non-hollow material. Preferably at least one of the core members is provided as a solid material; balsa; a vacuumised solid, e.g. vacuumised grains; and/or as a foam core having a layer, preferably a foil layer, wrapped around the foam core.
Preferably, said step of connecting comprises arranging said plurality of core members adjacent one another, and joining said plurality of core members to form a tip section having a desired aerodynamic profile.
Preferably, said step of joining comprises applying a layer around at least a portion of the surfaces of said plurality of core members. Preferably, the layer comprises a layer of fibre material, e.g. glass fibre, carbon fibre, and/or a hybrid thereof. Preferably, the layer comprises a portion of unidirectional fibre material. Additionally or alternatively, the layer comprises a portion of biax fibre material.
The method may comprise the step of applying a reinforcement material in portions of the tip section, e.g. in the main laminate section, the leading edge, and/or the trailing edge. The reinforcement material may comprise a unidirectional fibre layer, a pultruded profile, etc.
Preferably, said step of joining comprises infusing a fibre material with a resin, e.g. polyester resin, vinyl ester resin, etc., and curing said resin.
Preferably, said infusing comprises a one-shot infusion process.
In an alternative aspect, there is provided a tip section for a wind turbine blade, the tip section comprising a central load-bearing section, preferably a load bearing beam or spar box, and at least one non-load-carrying shape piece or skin member attached to said central load-bearing section.
Preferably, the tip section comprises a leading edge shape piece and a trailing edge shape piece.
In a further aspect, there is provided a tip section for a wind turbine blade, the tip section comprising a shell body, wherein a portion of the shell body projects from the remainder of the shell body in the spanwise direction towards the root-end-side of the tip section.
Preferably, said portion projects at least ½ metre from the remainder of the shell body, preferably between approximately 1-10 metres, further preferably approximately 1-5 metres, preferably approximately 1-2 metres.
Preferably, the shell body comprises an upwind side and a downwind side, wherein one of said upwind and downwind sides projects longer in the spanwise direction towards the root-end-side of the tip section than the other of said upwind and downwind sides.
There is also provided a mainboard section for a wind turbine blade for coupling with said tip section, wherein a portion of the tip-end-side of said mainboard section projects from the remainder of the mainboard section in the spanwise direction towards the tip-end-side of the mainboard section, the projecting portion of the mainboard section arranged to be complementary to the projecting portion of the tip section. Preferably, the projecting portion of the mainboard section is coupled with the projecting portion of the tip section, preferably by adhesive bonding.
In a further aspect, there is provided a modular wind turbine blade, the modular wind turbine blade comprising a tip section and a mainboard section, the tip section connected to the mainboard section at an interface, wherein
Preferably, at least one gripping arm is provided at a distal end of said at least one projecting element, wherein said at least one gripping arm is received within at least one coupling groove provided at or in said at least one receiving channel. Preferably, said at least one coupling groove has a greater depth than said at least one receiving channel. In one aspect, said at least one gripping arm and said at least one coupling groove may substantially form a linear ratchet mechanism.
In a further aspect, there is provided a modular wind turbine blade, the modular wind turbine blade comprising a tip section and a mainboard section, the tip section connected to the mainboard section at an interface, wherein
Preferably, the at least one coupling element and the connector are formed from a conductive material, wherein the at least one coupling element and the connector are conductively connected to a lightning down-conductor provided in the wind turbine blade.
In a further aspect, there is provided a modular wind turbine blade, the modular wind turbine blade comprising a tip section and a mainboard section, the tip section connected to the mainboard section at an interface, wherein
It will be understood that there is provided a tip section for a wind turbine blade as described in any of the above embodiments, and/or as manufactured by any of the above-described methods. There is further provided a wind turbine blade comprising such a tip section. Preferably, the tip section comprises between approximately ¼-⅙ of the spanwise length of the wind turbine blade. There is further provided a wind turbine comprising such a wind turbine blade.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
It will be understood that elements common to the different embodiments of the invention have been provided with the same reference numerals in the drawings.
The airfoil region 34 (also called the profiled region) has an ideal or almost ideal blade shape with respect to generating lift, whereas the root region 30 due to structural considerations has a substantially circular or elliptical cross-section, which for instance makes it easier and safer to mount the blade 10 to the hub. The diameter (or the chord) of the root region 30 is typically constant along the entire root area 30. The transition region 32 has a transitional profile 42 gradually changing from the circular or elliptical shape 40 of the root region 30 to the airfoil profile 50 of the airfoil region 34. The chord length of the transition region 32 typically increases substantially linearly with increasing distance r from the hub.
The airfoil region 34 has an airfoil profile 50 with a chord extending between the leading edge 18 and the trailing edge 20 of the blade 10. The width of the chord decreases with increasing distance r from the hub.
It should be noted that the chords of different sections of the blade normally do not lie in a common plane, since the blade may be twisted and/or curved (i.e. pre-bent), thus providing the chord plane with a correspondingly twisted and/or curved course, this being most often the case in order to compensate for the local velocity of the blade being dependent on the radius from the hub.
The thickness t of the airfoil varies along the chord 60. The deviation from a symmetrical profile is given by a camber line 62, which is a median line through the airfoil profile 50. The median line can be found by drawing inscribed circles from the leading edge 56 to the trailing edge 58. The median line follows the centres of these inscribed circles and the deviation or distance from the chord 60 is called the camber f. The asymmetry can also be defined by use of parameters called the upper camber (or suction side camber) and lower camber (or pressure side camber), which are defined as the distances from the chord 60 and the suction side 54 and pressure side 52, respectively.
Airfoil profiles are often characterised by the following parameters: the chord length c, the maximum camber f, the position df of the maximum camber f, the maximum airfoil thickness t, which is the largest diameter of the inscribed circles along the median camber line 62, the position df of the maximum thickness t, and a nose radius (not shown). These parameters are typically defined as ratios to the chord length c. Thus, a local relative blade thickness t/c is given as the ratio between the local maximum thickness t and the local chord length c. Further, the position dp of the maximum pressure side camber may be used as a design parameter, and of course also the position of the maximum suction side camber.
The wind turbine blade 10 generally comprises a shell made of fibre-reinforced polymer, and is typically made as a pressure side or upwind shell part 24 and a suction side or downwind shell part 26 that are glued together along bond lines 28 extending along the trailing edge 20 and the leading edge 18 of the blade 10. Wind turbine blades are generally formed from fibre-reinforced plastics material, e.g. glass fibres and/or carbon fibres which are arranged in a mould and cured with a resin to form a solid structure. Modern wind turbine blades can often be in excess of 30 or 40 metres in length, having blade root diameters of several metres. Wind turbine blades are generally designed for relatively long lifetimes and to withstand considerable structural and dynamic loading.
With reference to
Preferably, the connection between the sections 70,72 must be light weight and durable. While
Preferably, the tip section 70 can be provided in a variety of different lengths and geometries, to allow for scalability of design.
With reference to
In this embodiment, the tip section 70a comprises three cores arranged to form a leading edge portion 71a, a trailing edge portion 71b, and a main laminate portion 71c.
The core portions 71a,71b,71c are preferably three hollow braided infused cores, further preferably with pultruded profiles at the leading edge, trailing edge, and/or main laminate sections of the respective cores 71a,71b,71c.
The cores 71a, 71b,71c may comprise Glass Fibre Reinforced Polymer (GFRP), but it will be understood that carbon fibres may additionally or alternatively be used.
The cores 71a,71b,71c can be positioned together to effectively form a mandrel or forming core, to which skin layers, which may comprise layers of glass and/or carbon fibre material, can be applied to or braided around.
The package, including the cores 71a,71b,71c and the skin layers 74, may be placed within a mould to form the desired shape of the tip section 70. The package can then be infused with a resin and cured to form the tip section 70. Preferably, the package is infused in a one-shot moulding process. The skin layers 74 are preferably infused, but it will be understood that portions of the surfaces of the cores 71a,71b,71c may be infused with resin during the moulding process.
It will be understood that the cores 71a, 71b,71c may be formed on members (not shown) which may be retained in position within the interior of the cores 71a, 71b,71c before and/or during the infusion process, and removed thereafter. The members may comprise relatively rigid elements, flexible filling material and/or inflatable elements for ease of removal.
This embodiment provides a relatively light-weight tip section 70 which is relatively easy to manufacture, and may be suitable for automation. The tip section 70 comprises no adhesive bond lines, and accordingly eliminates the possibility of bond line failure in the tip section 70, while reducing the weight of the tip section 70. Scalability may be provided by simply lengthening tools used to form the core sections 71a, 71b,71c
A similar embodiment is indicated in
In this embodiment, in contrast to the embodiment of
The cores 76 may be arranged in a mould 78, preferably on top of at least one layer of fibre material, e.g. biax fibre material 80. Additional layers of fibre material may be provided adjacent the cores 76, e.g. unidirectional fibres 82 positioned beneath and on top of the cores 76 in the region of the main laminate portion of the tip section 70b. Further layers of fibre material (not shown) may be positioned on top of the cores 76 in the mould 78, before the mould 78 is closed and the fibre material infused with resin to form the tip section 70b.
Due to the use of non-hollow cores 76, it may be possible to reduce or eliminate the use of pultruded reinforcement elements in the tip section 70b, and/or to reduce or eliminate the use of separate forming members to form the initial cores.
It will be understood that the features of the embodiments of
A further embodiment of a tip section 70c according to the invention is shown in
The non-load-carrying shape pieces 84 may be attached to the load-bearing section 82 using any suitable connection, e.g. adhesive bonding or bonding via resin infusion joint, mechanical connectors, e.g. bolting, riveting.
This embodiment provides several advantages. In a first aspect, the joint between components is not located at the leading edge or trailing edge, and accordingly may only experience loading due to aerodynamic forces. Furthermore, the load concentrations and load path can be easily calculated using the central load-bearing section 82, which can easily be designed as appropriate. The load-bearing section 82 may be manufactured using any suitable manufacturing process, and can be relatively easily scaled as desired.
With reference to
An alternative embodiment of a tip section connection is illustrated in
Similarly, in the mainboard section (not shown) the side on the opposed surface to the projecting side 86 of the tip section 70d extends longer in the spanwise direction towards the tip end 14 of the blade 10.
This may be accomplished by extending the main laminate part of the corresponding projecting sections of the tip section and the mainboard section of the blade 10 by corresponding distances to create a stepped transition between the sections at the interface between sections.
Accordingly, the tip section 70d may be joined to the mainboard section by connecting the projecting portion of the tip section 70d with the projecting portion of the mainboard section. It will be understood that the sections may be joined using any suitable connection, as described above. Preferably, adhesive is applied along at least a portion of the interface between the sections, e.g. along bond lines provided at the edges of the surfaces of the shells of the projecting portions. Additionally or alternatively, the sections may be joined using overlamination between components.
A connection between the sections over a spanwise distance, e.g. at least 1-2 meters, can provide for a smooth transfer of loads between the blade sections. In addition, a relatively large glue area between sections can more easily distribute the shear forces involved in the structure. Furthermore, the configuration provides relatively easy access to glue surfaces before the tip section 70d is joined with the mainboard section.
In this embodiment, the mainboard section 72 may be provided with a relatively low pre-bend, wherein the tip section 70d may have a relatively larger pre-bend.
In
Coupling grooves 90a are provided at the opposite ends of the receiving channels 90 from the tip-end-side of the mainboard section 72a, the coupling grooves 90a having a greater depth than the adjacent receiving channels 90. The coupling grooves 90a extend in a direction substantially transverse to the spanwise direction.
For coupling of the tip section 70e and the mainboard section 72a, adhesive may be applied in the receiving channels 90 and/or on the internal surfaces of the projecting elements 88. The projecting elements 88 are received within the receiving channels 90 as the tip section 70e is moved towards the mainboard section 72a, wherein the projecting elements 88 may be deflected as the gripper arms 88a contact the surface of the receiving channels 90. Once the gripper arms 88a reach the end of the receiving channels 90, the arms 88a snap into the coupling grooves 90a at the end of the channels 90 to provide a mechanical connection between the sections 70e,72a.
The tip section 70e can then be further secured to the mainboard section 72a by the curing of suitable adhesive, and/or further mechanical connections, e.g. bolting, riveting, overlamination, etc.
Optionally, and as shown in
While in
While
Additionally or alternatively, while the embodiment of
Furthermore, while the gripper arms 88a and the coupling grooves 90a are shown as substantially straight elements, it will be understood that the arms 88a and/or grooves 90a may have any suitable profiles to provide for improved performance of the connection, e.g. a saw-tooth or dimpled profile. Additionally or alternatively, the projecting elements 88 and/or the receiving channels 90 may have appropriate profiling, e.g. to ensure that a minimum bond line distance is maintained between bond surfaces-corrugation, dimpling, etc.
This embodiment provides a resilient connection system, which can provide for improved quality control, as the connection between sections can be confirmed by a visual inspection of the insertion of the gripper arms into the coupling grooves, and/or an aural indication of the coupling via a “click” sound formed by the snapping of the arms 88a into the coupling grooves 90a.
In addition, while the embodiment of
With reference to
In this case, as the coupling elements 92 and the connection 94 may be provided as conductive metallic elements, they may be coupled with the lightning protection system of the blade 10, e.g. the connection 94 may be provided as a lightning receptor for the blade 10.
This embodiment provides a relatively simple and straightforward connections system, which can easily be implemented in existing blade manufacturing systems.
With reference to
With reference to
In a second aspect, spacers may be used at the interface between blade sections A and B, wherein the spacers act to set a bondline thickness between components. An adhesive or resin can be supplied to the interface to bond the sections together with an appropriate bondline thickness guaranteed.
While the embodiments have been shown with a longitudinally extending bondline, it is also possible to utilise a scarf joint or a double-scarf joint to form the interface. The joint may be formed directly between load-carrying structures of the two parts, e.g. between principal laminates of the two parts being integrated in the shell of said parts.
It will be understood that any of the features of the above embodiments may be used in combination with the features of any of the other embodiments presented above.
The figure also illustrates a schematic view of a cross-section of the mainboard section 120. The mainboard section comprises an aerodynamic shell with load-carrying principal laminates 121 integrated in the pressure side shell part and suction side shell part, respectively, the principal laminates forming spar caps. The aerodynamic shell may further as illustrated comprise load-carrying leading edge laminate(s) 122 and a load-carrying trailing edge laminate(s) 123. Further, the blade may comprise sandwich constructions 124 comprising a sandwich core material between fibre skins and arranged between the various load-carrying structures 121, 122, 123. The blade further comprises shear webs 125 that are connected internally in the blade between the principal laminates 121.
The tip section 110 is formed similar to the mainboard section, i.e. with load-carrying principal laminates 111 integrated in the aerodynamic shell and optionally a load-carrying leading edge laminate 112 and a load-carrying trailing edge laminate 113.
The tip section 110 and the mainboard section 120 are as illustrated connected to each other at the joining section 130 via a first layup 140 or insert forming a first scarf joint connecting the load-carrying principal laminates 111, 121 of the tip section and the mainboard section, respectively, a leading edge layup 150 or insert forming a leading edge scarf joint connecting the load-carrying leading edge laminates 112, 122 of the tip section and the mainboard section, respectively, and a trailing edge layup 140 or insert forming a trailing edge scarf joint connecting the load-carrying trailing edge laminates 113, 123 of the tip section and the mainboard section, respectively.
It is seen that the tip section 110 is formed such that the load-carrying principal laminate 111 comprises a recess 118 at the end facing the joining section 130, wherein the recess 118 comprises a taper section 119, where a thickness of the principal laminate 111 is tapered towards said end of the tip section 110. Similarly, the mainboard section 120 is formed such that the load-carrying principal laminate 121 comprises a recess 128 at the end facing the joining section 130, wherein the recess 128 comprises a taper section 129, where a thickness of the principal laminate 121 is tapered towards said end of the mainboard section 120.
The scarf joint is formed by a layup 140 that is arranged in the recesses 118, 128 and which is arranged to abut the taper section 119 of the principal laminate 111 of the tip section 110 and the taper section 129 of the principal laminate 121 of the tip section 120. Thereby, the layup forms a first scarf joint part to the tip section 110 and a second scarf joint part to the mainboard section 120.
The taper sections ensure that a strong assembly is achieved without any stiffness transitions. Further, the method provides a simple method of applying the layup to assemble the wind turbine blade and at the same time achieving a smooth aerodynamic finish between the tip section and the mainboard section of the blade. In general, it is recognised that the load-carrying laminates are formed by fibre-reinforced laminates that comprises a plurality of fibre-reinforcement layers, often comprising 10-50 or 20-50 fibre-reinforcement layers. The taper sections may be formed by arranging ends of the fibre-reinforcement layers in a tapered arrangement. The individual layers may be arranged as ply-drops such that a step-wise taper is achieved in order to form a stepped scarf joint surface, or the individual layers may be cut taperingly in order to form a smooth scarf joint surface. The taper sections may also be formed by a post-moulding operation, e.g. by grinding the end surface in order to form a taper section.
The circumferentially extending attachment part 270 may partly or wholly be formed as a pre-shaped or pre-cured solid part. It may for instance be possible to provide the parts that connect the layups 240, 250, 260 as solid parts and let layups be provided as wet or dry fibre-reinforcement material. However, it is also possible to form the circumferentially extending attachment part 270 as a preform, where the layups 240, 250, 260 are arranged on a backing scrim or layer. The backing scrim may form the outer surface of the joining section, or alternatively an over-lamination may be carried out in order to form the outer surface. The backing scrim or over-lamination layer may for instance be made of a biaxial fibre-reinforcement layer.
The circumferentially extending attachment may be formed as a single piece extending all the way around the blade, or alternatively it may as illustrated in
In the embodiments shown in
As previously mentioned, it is possible to provide the layup and scarf joints in a number of different ways. In a first highly advantageous method illustrated schematically in
In a second method illustrated in
In a third method illustrated in
In the previously described embodiments, the connections between the tip section and the mainboard section have been provided by a single set of recesses in load-carrying laminates and a single layup only. However, it is also possible to establish the connection by providing a plurality of sets of recesses and mating layups, e.g. two or three, in the various load-carrying laminates.
The invention is not limited to the embodiments described herein, and may be modified or adapted without departing from the scope of the present invention.
Embodiments of methods, tip sections, modular wind turbine blades and devices according to the invention are set out in the following items:
Item 1. A method of manufacture of a tip section for a wind turbine blade, comprising:
Item 2. The method of item 1, wherein the method comprises providing at least a leading edge core member and a trailing edge core member, preferably wherein the tip section further comprises a main laminate core member to be arranged between the leading edge core member and a trailing edge core member.
Item 3. The method of item 1 or item 2, wherein the method comprises providing at least one of the core members as a substantially hollow member, preferably wherein said at least one of the core members comprises a hollow braided infused core, preferably comprising glass fibre, carbon fibre, and/or a hybrid thereof.
Item 4. The method of any preceding item, wherein at least one of the core members comprises at least one pultruded reinforcement member.
Item 5. The method of any preceding item, wherein at least one of the core members is provided as a substantially non-hollow material, preferably at least one of the core members is provided as a solid material; balsa; a vacuumized solid, e.g. vacuumized grains; and/or as a foam core having a layer, preferably a foil layer, wrapped around the foam core.
Item 6. The method of any preceding item, wherein said step of connecting comprises arranging said plurality of core members adjacent one another, and joining said plurality of core members to form a tip section having a desired aerodynamic profile.
Item 7. The method of item 6, wherein said step of joining comprises applying a layer around at least a portion of the surfaces of said plurality of core members, preferably, the layer comprises a layer of fibre material, e.g. glass fibre, carbon fibre, and/or a hybrid thereof.
Item 8. The method of item 6 or item 7, wherein said step of joining comprises infusing a fibre material with a resin, e.g. polyester resin, vinyl ester resin, and curing said resin.
Item 9. The method of item 8, wherein said infusing comprises a one-shot infusion process.
Item 10. A tip section for a wind turbine blade, the tip section comprising a central load-bearing section, preferably a load bearing beam or spar box, and at least one non-load-carrying shape piece or skin member attached to said central load-bearing section, preferably, the tip section comprises a leading edge shape piece and a trailing edge shape piece.
Item 11. A tip section for a wind turbine blade, the tip section comprising a shell body, wherein a portion of the shell body projects from the remainder of the shell body in the spanwise direction towards the root-end-side of the tip section.
Item 12. The tip section of item 11, wherein said portion projects at least ½ metre from the remainder of the shell body, preferably between approximately 1-10 metres, further preferably approximately 1-5 metres, preferably approximately 1-2 metres.
Item 13. The tip section of item 11 or item 12, wherein the shell body comprises an upwind side and a downwind side, wherein one of said upwind and downwind sides projects longer in the spanwise direction towards the root-end-side of the tip section than the other of said upwind and downwind sides.
Item 14. A mainboard section for a wind turbine blade for coupling with tip section as described in any one of items 10-13, wherein a portion of the tip-end-side of said mainboard section projects from the remainder of the mainboard section in the spanwise direction towards the tip-end-side of the mainboard section, the projecting portion of the mainboard section arranged to be complementary to the projecting portion of the tip section, preferably the projecting portion of the mainboard section is coupled with the projecting portion of the tip section, preferably by adhesive bonding.
Item 15. A modular wind turbine blade, the modular wind turbine blade comprising a tip section and a mainboard section, the tip section connected to the mainboard section at an interface, wherein at least one projecting element projects from at least one of said tip section and said mainboard section and is received within at least one receiving channel provided on the other of said at least one said tip section and said mainboard section, wherein said at least one projecting element is secured within said at least one receiving channel, preferably using an adhesive bond.
Item 16. The modular wind turbine blade of item 15, wherein at least one gripping arm is provided at a distal end of said at least one projecting element, wherein said at least one gripping arm is received within at least one coupling groove provided at or in said at least one receiving channel, preferably, said at least one coupling groove has a greater depth than said at least one receiving channel.
Item 17. A modular wind turbine blade, the modular wind turbine blade comprising a tip section and a mainboard section, the tip section connected to the mainboard section at an interface, wherein
Item 18. The modular wind turbine blade of item 17, wherein the at least one coupling element and the connector are formed from a conductive material, wherein the at least one coupling element and the connector are conductively connected to a lightning down-conductor provided in the wind turbine blade.
Item 19. A modular wind turbine blade, the modular wind turbine blade comprising a tip section and a mainboard section, the tip section connected to the mainboard section at an interface, wherein
Item 20. A device substantially as shown and described herein.
This application is a continuation of U.S. patent application Ser. No. 15/317,229, filed on Dec. 8, 2016, which was filed as a National Phase application filed under 35 U.S.C. § 371 as a national stage of PCT Application No. PCT/EP2015/063079, filed on Jun. 11, 2015, which claimed the benefit of United Kingdom Application No. 1410429.3, filed on Jun. 11, 2014, the content of each of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15317229 | Dec 2016 | US |
| Child | 18897168 | US |
