Blade assembly for wind turbine blade, wind turbine and method for building wind turbine blade

Abstract

A blade shell assembly for a wind turbine blade shell is described. The blade shell assembly includes a first element (200) having a first mating surface (201) and a second element (300) having a second mating surface (301). The first mating surface (201) and the second mating surface (301) are adapted to abut each other in an assembled state. The second element (300) comprises one or more grooves (310) capable of generating a spring effect to close a gap (450) between the first element (200) and the second element (300), the gap (450) extending substantially in a direction (402) substantially perpendicular to the second mating surface (301) or the first mating surface (201). Furthermore, a method for building a blade shell of a wind turbine blade and a wind turbine blade are described.

Description

Technical Field

[0001] The present subject matter generally relates to a method for building a wind turbine blade, a blade shell assembly for building a wind turbine blade, and a wind turbine blade. In particular, the present subject matter relates to a method for building a wind turbine blade having several elements, a blade shell assembly having several elements, and a wind turbine blade including the blade shell assembly. Background Art

[0002] Wind power is considered one of the cleanest and most environmentally friendly energy sources currently available, and for this reason, wind turbines have received increasing attention. Modern wind turbines typically include a tower, a generator, a gearbox, a nacelle, and a rotor with one or more rotor blades. The rotor blades capture kinetic energy from the wind using the known airfoil principle, and the kinetic energy is transferred by rotational energy to rotate a shaft, which couples the rotor blades to a gearbox, or directly to a generator if a gearbox is not used. The generator then converts the mechanical energy into electrical energy that can be deployed to the utility grid.

[0003] The blades of a wind turbine are elaborately designed and often have a complex shape to increase the efficiency of the wind turbine. When producing the blades of a wind turbine, various materials are used. For example, different materials may be used within one blade to take into account different load conditions along the length of the blade. Between two adjacent materials for one blade there is a transition between two different elements of the blade shell.

[0004] However, the geometry of wind turbine blades is very sensitive to deviations, such as gaps or height differences. For example, transitions between different elements of the blade shell may result in irregularities on the surface of the wind turbine blade. Irregularities on the surface of the wind turbine blade may result in variations in the contact between the blade surface and the wind, which in turn may affect the energy yield of the wind turbine. Furthermore, irregularities may result in premature wear and damage on the wind turbine blade. The cost of repairing premature wear and damage is high.

[0005] Hence, the present disclosure provides a method for building a wind turbine blade shell, a blade shell assembly for a wind turbine blade shell, and a wind turbine blade according to the independent claims. Summary of the invention

[0006] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0007] In one aspect, the present disclosure is directed to a method for building a wind turbine blade shell comprising a first element and a second element. The first element has a first mating surface and the second element has a second mating surface. The method comprises: forming one or more grooves in the second element, wherein the one or more grooves in the second element are capable of generating a spring effect for the second element substantially in a direction substantially perpendicular to the second mating surface (typically denoted as the second direction); placing the first element and the second element adjacent to each other, wherein the first mating surface of the first element and the second mating surface of the second element face each other; and closing a gap between the first element and the second element in a direction substantially perpendicular to the second mating surface by pressing the first mating surface and the second mating surface together.

[0008] In general, there is a tolerance range regarding the size of the gap. However, the gap between two elements of a wind turbine housing is difficult to measure and identify, as the gap is (only) visible from the top, which makes it difficult to complete a quality inspection. Failure to identify the gap can lead to problems with the blade, such as curing cracks in the brittle polyester resin, wrinkles in the skin layer of the blade, or time-consuming repair work.

[0009] Thus, the method for building a wind turbine blade shell according to embodiments described herein allows eliminating a gap between a first element and a second element of the blade shell. In particular, eliminating the gap in an easy and uncomplicated manner without using additional process steps as known in the art, such as using a filling material in the gap or the like.

[0010] For example, if polyester resin is used to fill a large gap (as is done in known production methods), the polyester resin is susceptible to cracking due to curing residual stresses. When the polyester resin shrinks, but is constrained by the rigid elements of the blade shell, the polyester resin cannot shrink. Instead, the polyester resin will crack. The larger the gap, the more the polyester resin will crack.

[0011] Embodiments of the present application are directed to eliminating gaps from the outset. For example, the formation of the elements is selected such that a gap between two elements of a wind turbine blade can be avoided. Avoiding or eliminating gaps before resin application results in a smooth surface of the blade shell and the blade in general. The smooth blade surface in turn helps increase the energy yield of the wind turbine and extend the service life of the wind turbine.

[0012] In one aspect, the present disclosure is directed to a blade shell assembly for a wind turbine blade shell. The blade shell assembly includes a first element having a first mating surface and a second element having a second mating surface. The first mating surface and the second mating surface are adapted to abut against each other in an assembled state. The second element includes one or more grooves that are capable of generating a spring effect to close a gap between the first element and the second element, the gap extending substantially perpendicularly to the first mating surface and / or the second mating surface.

[0013] In one aspect, the present disclosure is directed to a wind turbine comprising a blade assembly according to embodiments described herein.

[0014] The blade shell assembly according to embodiments described herein and the wind turbine blade comprising the blade shell assembly provide an easy and cost-conscious way to provide a wind turbine blade with a smooth surface that is substantially free of cracks and wrinkles due to gaps between elements of the wind turbine blade shell. By providing the second element in the elements of the wind turbine blade according to embodiments described herein, gaps between elements can be avoided or eliminated right from the start, in particular before the elements are infused with resin or the like to build the wind turbine blade.

[0015] These and other features, aspects and advantages of the present invention will be further supported and described with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and together with the description serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] A complete and enabling disclosure of the present invention including the best mode thereof to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of a wind turbine according to an embodiment of the present disclosure; Figure 2 shows a schematic perspective view of a wind turbine blade according to an embodiment of the present disclosure; Figure 3 shows a schematic cross-sectional view of a wind turbine blade according to an embodiment of the present disclosure; Figure 4 shows a detail of a schematic cross-sectional view of an element of a wind turbine blade according to an embodiment of the present disclosure; Figures 5 to 12 a schematic view showing a first element and a second element of a wind turbine blade according to an embodiment of the present disclosure; and Fig.13 A schematic flow chart of a method for building a wind turbine blade according to an embodiment of the present disclosure is shown.

[0017] Individual features depicted in the figures are shown relative to each other and are therefore not necessarily shown to scale. Similar or identical elements in the figures are denoted by the same reference numerals even if they are shown in different embodiments. DETAILED DESCRIPTION

[0018] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are shown in the accompanying drawings. Each embodiment is provided for the purpose of illustrating the present invention and should not be construed to limit the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention, for example, features illustrated or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present invention is intended to cover such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0019] Figure 1 1 is a perspective view of a portion of an exemplary wind turbine 100. In the exemplary embodiment, wind turbine 100 is a horizontal-axis wind turbine. Alternatively, wind turbine 100 may be a vertical-axis wind turbine. Wind turbine 100 includes a housing for a generator ( Figure 1 The nacelle 102 is mounted on a tower 104 ( Figure 1 104 is a tower 104 mounted on a portion of a tower 104 (shown in FIG. 104 ). Tower 104 may have any suitable height that facilitates operation of wind turbine 100 as described herein. Wind turbine 100 also includes a rotor 106 that includes three wind turbine blades 108 attached to a rotating hub 110. Hereinafter, the wind turbine blades are also referred to as wind turbine rotor blades and are simply referred to as rotor blades. Alternatively, wind turbine 100 includes any number of blades 108 that facilitate operation of wind turbine 100 as described herein. In the exemplary embodiment, wind turbine 100 includes a gearbox ( Figure 1 ), the gearbox is operably coupled to the rotor 106 and the generator ( Figure 1 ).

[0020] Rotor blades 108 are spaced about hub 110 to facilitate rotation of rotor 106 to enable kinetic energy to be transferred from the wind into usable mechanical energy, and subsequently, electrical energy.

[0021] In one embodiment, rotor blades 108 have a length ranging from about 15 meters (m) to about 130 m. Alternatively, rotor blades 108 may have any suitable length that enables wind turbine 100 to function as described herein. For example, other non-limiting examples of blade lengths include 20 m or less, 37 m, 48.7 m, 50.2 m, 52.2 m, or a length greater than 91 m, such as 100 m or greater.

[0022] According to embodiments described herein, each rotor blade comprises a wind turbine blade shell.

[0023] The term "wind turbine blade shell" as used herein may be understood as the shell of a wind turbine blade. In particular, the shell of a wind turbine blade may be described as the outer side or the outside of a wind turbine blade. According to some embodiments, the shell of a wind turbine blade may be the surface of a wind turbine blade which is impacted by wind and other environmental influences, such as weather conditions. In some embodiments, the shell of a wind turbine blade may be described as a kind of skin of a wind turbine blade. In particular, the shell of a wind turbine blade may be formed in an aerodynamic manner, in particular for adapting the blade shell for efficient energy production. In some embodiments, the shell of a wind turbine blade may be adapted to withstand its own loads as well as the forces of wind and weather acting on the wind turbine blade. According to some embodiments, the shell of a wind turbine blade may surround other elements of the wind turbine blade, such as reinforcing elements, forming elements, load-bearing elements, etc.

[0024] When wind strikes rotor blades 108 from wind direction 28, rotor 106 rotates about rotation axis 30. As rotor blades 108 rotate and are subjected to centrifugal forces, rotor blades 108 are also subjected to various forces and moments. Thus, rotor blades 108 may deflect and / or rotate from a neutral position (or non-deflected position) to a deflected position.

[0025] Additionally, the pitch angle of rotor blades 108 (i.e., the angle that determines the projection of rotor blades 108 relative to the wind direction) may be varied by the pitch system to control loads and the power generated by wind turbine 100 by adjusting the angular position of at least one rotor blade 108 relative to the wind vector. During operation of wind turbine 100, the pitch system may vary the pitch angle of rotor blades 108 such that rotor blades 108 move to a feathered position such that the projection of at least one rotor blade 108 relative to the wind vector provides a minimum surface area of ​​rotor blade 108 oriented toward the wind vector, which facilitates reducing the rotational speed and / or facilitating stalling of rotor 106.

[0026] The blade pitch of each rotor blade 108 may be individually controlled by a wind turbine controller or by a pitch control system. Alternatively, the blade pitch of all rotor blades 108 may be controlled simultaneously by the control system.

[0027] Moreover, in the exemplary embodiment, as wind direction 28 changes, the yaw orientation of nacelle 102 may be rotated about yaw axis 38 via a yaw system to position rotor 106 relative to wind direction 28 .

[0028] The yaw system may include a yaw drive mechanism provided by the nacelle 102 .

[0029] Furthermore, the yaw system may also be controlled by the wind turbine controller.

[0030] In order to properly position the nacelle 102 with respect to the wind direction 28 and to detect the wind speed, the nacelle 102 may also include at least one meteorological mast, which may include a wind vane and anemometer. The mast 107 may provide information about environmental conditions to the wind turbine controller. This may include wind direction and / or wind speed as well as ambient temperature, ambient humidity, precipitation type and / or precipitation amount (if any).

[0031] Figure 2 A perspective view of a single rotor blade 108 or a single wind turbine blade 108 according to embodiments described herein is shown. Typically, a rotor blade 108 or wind turbine blade extends from a root 111 to a tip 112 . Figure 2 The shape of rotor blade 108 is roughly indicated in FIG. 1 by a line extending across the width of the rotor blade. Figure 3 An example of a cross section 113 of a turbine blade 108 is depicted in FIG.

[0032] Figure 3 A cross section 113 according to some embodiments described herein is shown in detail in . Typically, the cross section 113 of the wind turbine blade 108 has a defined shape for achieving an optimized result in energy yield. Figure 3 The example of a cross section 113 of a wind turbine blade 108 shows a portion of a blade shell according to some embodiments described herein. Figure 3 In the example of the cross section 113 shown in FIG. 1 , the blade shell comprises a first element 200 and a second element 300 .

[0033] According to some embodiments, the first element 200 may be a load-bearing element of a turbine blade. In particular, the first element may be represented as a main spar element of a wind turbine blade. For example, the first element 200 described in the embodiments herein may be formed as a stack of layers of one or more materials. In one example, the first element 200 may be a stack of carbon material layers, in particular a stack of pultruded carbon material layers. In some embodiments, the first element 200 may be represented as being made by a carbon pultrusion. According to some embodiments, the first element 200 may include a sandwich between the carbon material layers. In particular, the sandwich may include an infusion material placed between the carbon material layers. According to some embodiments that may be combined with other embodiments described herein, the infusion material may include a resin, such as vinyl ester, epoxy resin and / or polyurethane. According to some embodiments, the first element may also be represented as a spar cap for a wind turbine blade.

[0034] According to some embodiments described herein, Figure 3 A second element 300 of a blade shell of a wind turbine blade 108 is also shown. Typically, the second element 300 is arranged near the first element 200. In particular, the second element 300 is arranged to abut or substantially abut the first element 200. According to some embodiments, the second element 300 may be a core element or core material for a wind turbine blade. In particular, in some embodiments, the second element 300 may be at least one of a substantially continuous material, a substantially rigid material, and a substantially impermeable material. According to some embodiments, a continuous material may be understood as a material having substantially no regularly occurring holes therein, or having no regularly occurring pores. According to some embodiments, a rigid material may be understood as a material capable of maintaining the shape of a wind turbine blade shell under operating conditions of the wind turbine, in particular at a wind turbine site. According to some embodiments, as described in detail below, an impermeable material may be understood as a material that is impermeable to a resin, or may be understood as a material that does not absorb a resin, such as a resin used to form a blade shell.

[0035] In some embodiments, the second element may include one or more of the following materials: foam, balsa wood, PET (especially PET foam), PVC (especially PVC foam), polyurethane, especially polyurethane foam, MMA (methacrylate), vinyl ester (especially type A) and polyurethane (PU).

[0036] like Figure 3 As can be seen in the example of , according to some embodiments, the additional element (eg, the additional portion of the second element) may be a portion of a blade shell of the turbine blade 108. According to some embodiments, Figure 3 Also shown is a shear web 114 which is used, in particular, for stabilizing a blade shell of a wind turbine blade.

[0037] Figure 4 Shows Figure 3 A more detailed view of a portion of a blade shell exemplarily shown in FIG. The detailed view shows that the first element 200 comprises several layers of material, or in particular several layers with a sandwich in between. In addition, Figure 4 The detailed view of shows that the second element 300 is arranged adjacent to the first element 200. Typically, the first element, e.g. a main spar element of a wind turbine blade, may be produced in an offline mould. In particular, the main spar may be made of a stack of layers infused with a vinyl ester resin. According to some embodiments, after producing the first element, the first element may be placed in a blade shell mould 115. Typically, the blade mould with the first element and the second element is infused with a material, such as a resin material, e.g. polyester, for forming the blade shell.

[0038] According to the embodiments described herein, Figure 4 As can be seen in the figure, the core material of the second element 300 (examples of core material may be, for example, balsa wood, PET foam and / or PVC foam) may be placed against and in particular adjacent to the first element forming the main spar. During the placement process of the main spar and the core material (i.e. the first element and the second element), it has been shown that fitting the core material to the (pultruded) main spar may be difficult. However, the assembly elements of the blade shell result in a smooth transition. Mismatches of elements such as the main spar elements and the core elements may result in gaps and height steps on the surface of the rotor blade. This in turn may mean that there is no smooth transition. If there are gaps or height steps that exceed a defined tolerance value (e.g. in the range of a few millimeters), the transition from the core to the main spar may not be smooth enough for reliable and efficient operation of the wind turbine. In this case, extensive rework may be required (leading to extended cycle times and additional costs, which are unacceptable).

[0039] According to some embodiments, the present disclosure provides solutions how the first and second elements (produced offline) can be assembled in an efficient and high-quality manner. Typically, the solutions according to the embodiments described herein present an improvement in the transition of the core to the main spar, such that high quality is achieved, especially compared to known production techniques.

[0040] Figure 5 An example of an assembly situation when the first component 200 and the second component 300 are placed adjacent to each other is shown. Typically, the first component 200 includes a first mating surface 201 and the second component 300 includes a second mating surface 301.

[0041] The term "mating surface" as used in the embodiments described herein may be understood as a surface of an element that may be in a mating state with another mating surface of another element. More typically, the first mating surface and the second mating surface may be adapted to be mated with each other. In particular, the mating surface as described herein may be understood as a surface that is not yet in a mating state with another mating surface, or a surface that will be mated when assembling the elements, or a surface that is adapted to be mated in some embodiments. According to some embodiments, the mating surface may be adapted to be mated with another mating surface by the shape of the surface, the design of the surface, the surface characteristics (such as roughness, shape, porosity, etc.), the material of the surface, the orientation of the surface, etc.

[0042] Figure 5 The first mating surface 201 and the second mating surface 301 are shown to be typically substantially as in Figure 5 The coordinate system exemplarily shows a first direction 401 extending in the first direction 401. According to some embodiments that can be combined with other embodiments, the first direction 401 can extend substantially in the vertical direction. In some embodiments, the first direction 401 can be inclined relative to the vertical direction.

[0043] The term "substantially" as used in the embodiments described herein may be understood to mean that the characteristic represented by "substantially" may have certain deviations. For example, the orientation of the surface extending substantially in the first direction may include a deviation of typically up to 15° from the first direction, more typically up to 10° from the first direction, and even more typically up to 5° from the first direction. According to some embodiments, the first mating surface and the second mating surface may have a deviation different from the substantially first direction. According to some embodiments, the term "substantially vertical" may include a deviation of up to 15° from the vertical direction, more typically up to 10° from the vertical direction, and even more typically up to 5° from the vertical direction. Therefore, a characteristic that is not measured in degree and described as "substantially" may include a deviation of typically up to 15%, more typically up to 10%, and even more typically up to 5% from the characteristic.

[0044] Back to Figure 5 , as explained above, in some embodiments, Figure 5The first element 200 and the second element 300 shown in the figure may be placed in a blade shell mold to form a blade shell. A gap 450 may appear between the first element 200 and the second element 300, for example due to manufacturing tolerances, deviations in the size of the shell, temperature changes, material changes, etc. Typically, the gap 450 may extend between the first mating surface 201 of the first element 200 and the second mating surface 301 of the second element 300. According to embodiments described herein, the gap 450 may extend between the first mating surface and the second mating surface (in an unassembled stage), and may extend substantially perpendicular to the first mating surface and / or the second mating surface. In some embodiments, the size of the gap may typically be as shown in FIG. Figure 5 The second direction 402 is measured in the second direction 402 exemplarily shown in the coordinate system beside, and the second direction 402 may be substantially perpendicular to the first direction 401. In some embodiments, the second direction 402 may extend substantially in a horizontal direction. According to some embodiments, the second direction 402 is a direction substantially perpendicular to the second mating surface of the second component 300.

[0045] In some embodiments, the gap has a width in the second direction 402 of typically between about 0.1 mm and about 10 mm, more typically between about 0.5 mm and about 7 mm, and even more typically between about 1 mm and about 5 mm. According to some embodiments, gaps greater than 2 mm or 3 mm may be avoided.

[0046] Figure 5 A second element 300 including a groove 310 according to embodiments described herein is shown. Typically, the second element 300 includes at least one groove. More typically, the second element includes two or more grooves. In some embodiments, the number of grooves in the second element 300 may typically be between 1 and 15, more typically between 1 and 10, and even more typically between 2 and 8. Figure 6 An example in which three grooves 310 are formed in the second member 300 is shown.

[0047] As used herein, the term "groove" may be understood as a cut or gap in an element of a wind turbine blade. According to some embodiments, a groove may also be denoted as a recess, a notch, a slot or a cutout. In some embodiments, a groove as described herein may have a defined orientation, shape and size. Typically, the orientation of the groove may be measured along the direction of maximum extension of the groove. For example, the orientation of a groove having an elongated shape may be measured along the longitudinal direction of the groove. According to some embodiments, the defined (and limited) size of a groove as described herein may depend on the size of the element in which the groove is located. According to some embodiments, the shape of the groove as described herein may be selected according to the purpose of the groove, the element in which the groove is located (especially the shape of the element in which the groove is located, the material of the element in which the groove is located), production considerations, etc. For example, a groove as described herein may have any geometric shape, such as a substantially triangular shape, a substantially quadrilateral shape, a substantially polygonal shape, a shape with or without rounded corners, a substantially circular shape, a shape representing a segmented circle, a segmented ellipse, a shape comprising a straight line, or a shape comprising a combination of the above-mentioned geometric shapes, etc.

[0048] Figure 5 An embodiment is shown in which the groove is formed from the top toward the bottom of the second element 300 (when the groove is formed from the top toward the bottom of the second element 300). Figure 5 In some embodiments, the groove(s) in the second element 300 may be formed from the bottom toward the top of the second element. According to some embodiments in which the second element includes more than one groove, the orientation of the groove may vary. Figure 6 An embodiment of a second element 300 having three grooves 310 is shown. Figure 6 In the example of , one groove extends from the top to the bottom, and two grooves extend from the bottom to the top. According to some embodiments, the orientation of the grooves can be varied to suit the intended use and can be selected accordingly without being limited to the examples shown in the figures and described in detail in the present disclosure.

[0049] As mentioned above, the one or more grooves may have a defined size. Typically, the one or more grooves 310 of the second element 300 have a defined size in the first direction 401 and the second direction 402. For example, Figure 5The size of the groove 310 in the first direction is shown as a first direction size 404. Typically, the size of the groove can be measured from the surface of the second element 300 in which the groove is formed to the bottom or end of the groove 310. According to some embodiments, the first direction size 404 of the groove described herein can typically extend over at least 50%, more typically at least 65%, and even more typically at least 90% of the height 403 of the second element 300 in the first direction 401. In some embodiments, the first direction size 404 of the groove described herein can typically extend over about 80% of the height 403 of the second element 300 in the first direction 401.

[0050] like Figure 5 , according to some embodiments that can be combined with other embodiments described herein, the groove 310 can have a second directional size 405 extending in the second direction 402. Typically, the second directional size 405 of the groove 310 can be measured on the surface of the second element in which the groove is formed. Typically, the second directional size 405 of the groove 310 can extend in the width direction of the second element, which can correspond to the second direction 402 according to some embodiments described herein. In some embodiments, the size of the groove 310 in the second direction 402 can change (such as increase or decrease) along the extension of the groove 310 in the first direction 401. For example, the size of the groove 310 in the second direction 402 decreases along the first directional size 404 of the groove 310. According to some embodiments, the second directional size 405 of the groove can typically be between about 5% and about 70%, more typically between about 10% and about 60%, and even more typically between about 20% and about 50% of the first directional size 404 of the groove 310. In some embodiments, the second dimension 405 of the groove may typically be between about 15% and about 30% of the first dimension 404 of the groove 310. According to some embodiments, Figure 5 The groove shown in FIG. 1 may be represented as having a tapered shape.

[0051] Figure 7 An embodiment of a first element 200 and a second element 300 is shown, wherein the second element 300 has three grooves 310 formed in the second element 300. According to some embodiments described herein (which may be combined with other embodiments described herein), Figure 7 The groove 310 in Figure 6 For example, especially with Figure 5 and Figure 6 When compared with the grooves shown in the embodiment, Figure 7 The groove 310 shown in FIG. 3 has a smaller ratio of the size in the second direction to the size in the first direction.

[0052] According to embodiments described herein, the one or more grooves can generate a spring effect in the second element.

[0053] As used herein, the term "spring effect" may be understood as an effect that causes an object or element to act (at least partially) like a spring, especially when compressed or stretched. In particular, the spring effect generated for an element according to the embodiments described herein may cause the element to store mechanical energy. Typically, an element capable of storing mechanical energy includes elastic properties. According to some embodiments, the elastic properties of the element for which the spring effect is generated may be achieved by geometric features or material properties or both. According to the embodiments described herein, the spring effect is generated and achieved by defined geometric features (such as grooves, cutouts, recesses, notches, slots, cutouts, etc.). For example, if an element having a groove formed therein is compressed or stretched from a static position (i.e., a position where no force acts on the element), the element will apply an opposite force. In some embodiments, the second element (in addition to the geometric features that generate the spring effect) may be made of an elastic material to allow the element to be compressed more easily.

[0054] According to some embodiments, the spring effect as described herein may be a spring effect in a defined direction. For example, the force applied by the element having the spring effect may point in a defined direction. According to embodiments described herein, the defined direction of the spring effect may depend on the geometry of the element providing the spring effect and / or the material of the element providing the spring effect.

[0055] According to some embodiments, the groove in the second element being able to generate a spring effect may be understood as the groove enabling the second element (or a portion of the second element) to act as a spring-like element.

[0056] According to some embodiments, which can be combined with other embodiments described herein, the one or more grooves provide a local softening effect on the core material. The local softening effect can be described as an effect present in a portion of the core material, wherein the one or more grooves are located in the portion. Typically, the one or more grooves may provide a locally lower spring rate of the (optionally elastic) core material. Thus, the core material is able to adapt to the shape of the spar cap, in particular substantially unaffected by spar cap manufacturing variations or core material variations along the span of the blade.

[0057] Typically, the spring effect generated or enabled by the one or more grooves in the second element exists (only) during assembly of the blade shell. Once the blade shell is completed (or, for example, once the different elements of the blade shell are infused with resin), the second element may no longer be able to provide a spring effect (or it may be reduced to a great extent). For example, the elements of the blade shell may be fixed in defined positions (e.g., positions in which the gaps between the elements are significantly reduced or even eliminated). It will be appreciated that the resin infused in the blade shell mould (as explained in detail below) may be a kind of fixation of the current position of the elements. Once the resin cures, further movement (such as drift) of the individual elements relative to each other is largely prevented.

[0058] Typically, the first element 200 and the second element 300 may be placed adjacent to each other (e.g., in a blade shell mold), and the mating surfaces of the respective elements may be brought into contact with each other (as far as possible). Typically, the first element and the second element may be pressed toward each other, for example, when placed in a blade shell mold, so that the mating surfaces are brought into contact with each other. When the compressive force applied during the installation of the first element and the second element is reduced, for example, due to unplanned space provided by production tolerances of the elements, production tolerances of the blade shell mold, temperature conditions, lack of surface bonding, etc., the mating surfaces of the first element and the second element may drift apart. When the mating surfaces of the first element and the second element drift apart, gaps may occur when using known production techniques, which have the above-mentioned effects on the wind turbine shell. The second element with one or more grooves according to the embodiments described herein allows the gap to be filled with the second element by providing flexibility regarding the extension of the second element in the second direction. For example, the spring effect generated by the one or more grooves in the second element produces a large extension of the second element in the second direction. By using the second element according to the embodiments described herein, the spring provided by the one or more grooves in the second element can apply a force that avoids or retains the gap. In particular, the second element may be adapted such that expansion of the second element (eg, after compression) fills a gap between the first element and the second element.

[0059] According to some embodiments, the second element with one or more grooves according to the embodiments described herein provides greater flexibility for the first element and the second element to be produced. For example, the width of the first element and the second element in the second direction can be selected within a wider range (compared to known elements) without the risk of a gap appearing or remaining. In this way, the production of the element can be facilitated and therefore can be less expensive. Avoiding the appearance or retention of gaps can also avoid subsequent machining and result in less expensive subsequent production work. Typically, using the method and assembly according to the embodiments described herein to make the elements of the blade shell without gaps not only reduces production costs, but also leads to greater energy production during operation of the wind turbine.

[0060] like Figure 5 , 6 7 (and some other figures), the mating surface 201 is drawn as being substantially perpendicular to the mold surface 115 (or extending substantially in the first direction). According to some embodiments, which may be combined with other embodiments described herein, the mating surface 201 may not be substantially perpendicular to the mold surface, but may in particular be inclined to a certain degree. Typically, there may be a positive draft angle of several degrees on the mating surface 201 to ensure that the spar cap can be demoulded. Typically, this angle may vary along the length or span of the blade, since the main spar elements (typically made of square pultrusion material) may be placed into the curved mold surface. The local softening effect of one or more grooves in the core material (or the effect of the grooves producing a lower spring rate, as explained above) allows for better core-to-main spar mating along the span of the blade (especially in the case of inclined mating surfaces). In addition, geometric variations in the geometry of the spar cap caused by local manufacturing may be absorbed and compensated by the local softening of the core material (especially the local lower spring rate of the core material).

[0061] Figure 8 An example of a main spar element having a mating surface 201 that is inclined at an angle (such as, typically between about 1° and about 20°, more typically between about 2° and about 15°, and even more typically between about 2° and about 10°) compared to an orientation perpendicular to the mold surface is shown. In other words, the first mating surface 201 may be substantially offset along the first direction in which it extends. Figure 8 According to some embodiments, Figure 8 The main spar element 200 shown in FIG. 2 provides a variation in the angle of the mating surface 201. Typically, the angle of the inclined surface 201 may vary from a first end 211 to a second end 212. Typically, the variation in angle may extend over the length or span of the blade.

[0062] Figure 8 The embodiment of the spar cap element 200 shown in shows local variations 213 in the spar cap geometry (eg, due to manufacturing variations).

[0063] Fig. 9 An embodiment of the second element is shown, wherein the groove has a Figures 5 to 7 Typically, Fig. 9The groove 310 (or cutout) in the second element has a curved shape, or the wall of the groove 310 has a curvature. More typically, the curvature of the wall of the groove is formed so that the groove is substantially pointed at the end. According to some embodiments, the material surrounding the groove of the second element may be represented as having a substantially serpentine shape. In general, the shape of the one or more grooves may affect the stiffness of the spring effect generated by the one or more grooves in the second element.

[0064] Fig.10 An embodiment of a second element is shown having a groove 310 having a shape that is essentially a portion of an ellipse, or a curvature that results in rounded ends of the groove.

[0065] Fig.11 An embodiment of a second element is shown having a groove 310 having a substantially rectangular shape, or the shape of an open quadrilateral.

[0066] Fig.12 Embodiments are shown that can be combined with other embodiments described herein. Fig.12 In the embodiment of the first element 200 and the second element 300 shown in FIG. 1 , as in other embodiments described herein, three grooves 310 are exemplarily shown. Fig.12 The second element 300 provides a transverse groove 311 .

[0067] According to some embodiments described herein, the term “lateral groove” may be understood as a groove extending in a direction different from the direction of the groove 310 . For example, Fig.12 The longitudinal extension of the groove 310 in the embodiment extends substantially in the first direction 401, and Fig.12 The longitudinal extension of the transverse groove 311 in the second element 300 extends substantially in the second direction 402. Although the transverse groove 311 may be indicated as "transverse" compared to the groove 310, the angle between the longitudinal direction of the groove 310 and the longitudinal direction of the transverse groove 311 may be arbitrarily selected, for example according to the target or production parameters of the groove. In some embodiments, the groove 310 may be indicated as a main groove 310 compared to the transverse groove 311. For example, the main groove 310 may have a larger size than the transverse groove 311 (for example, measured in the longitudinal direction of the groove, respectively). In some embodiments, the transverse groove 311 may be located in the section of the second element 300 where the main groove 310 is located. According to some embodiments, the transverse groove 311 may be formed in the wall of the main groove 310. According to some embodiments, the groove as described herein is typically capable of solving and in particular balancing the height difference between the main spar element and the core element in addition to filling the gap in the second direction 402 (as described in detail above). In some embodiments, the transverse groove 311 may be designed to allow solving the height difference that may exist between the first element 200 and the second element 300.

[0068] although Figures 9 to 12 Three (main) grooves 310 with alternating orientations (e.g., starting at the top surface of the second element or the bottom surface of the second element) are shown separately, but it is understood that the shape of the grooves in the figure is not limited to the combination shown exemplarily in the figure. On the contrary, each shape of the groove can appear in any number and appear in each orientation (the orientation typically includes the angle starting at the top surface or bottom surface of the second element and the longitudinal direction of the corresponding groove). It is even possible to combine grooves of different shapes and sizes in a single element. According to some embodiments, the size of the main grooves and the transverse grooves may be uniform or non-uniform. For example, the size of the grooves as described herein may vary within the second element. In some specific embodiments, there may also be grooves of smaller size in the same direction as the main grooves.

[0069] In general, the shape of the one or more grooves in the second element is not limited to the shapes exemplarily shown in the figures. Other (and in particular arbitrary) shapes of grooves can be used to achieve the spring effect. For example, the shape of the groove can be (or can be similar to) a substantially rectangular groove, a substantially circular groove, a substantially triangular groove, a substantially polygonal groove, a substantially elliptical groove, a groove with a curved or arcuate wall (in particular with any arbitrary curvature), a groove with a tapered shape, a groove with a substantially serpentine shape, etc. According to some embodiments that can be combined with other embodiments described herein, the shape of the one or more grooves can depend on manufacturing factors, such as rapid prototyping, the shape of the tool used, the duration of the forming process, etc.

[0070] Fig.13 A flow chart of a method 500 for building a wind turbine blade shell is shown. Typically, the wind turbine blade shell comprises (in its mounted state) a first element 200 and a second element 300. According to some embodiments, which can be combined with other embodiments described herein, the first element and the second element may be the first element and the second element as described in the embodiments herein. In particular, the first element 200 has a first mating surface 201 and the second element 300 has a second mating surface 301. Typically, the first mating surface and the second mating surface are adapted to mate with each other. More typically, as explained in detail above, the first mating surface and the second mating surface have an orientation in a first direction 401.

[0071] In block 510, the method 500 includes forming one or more grooves 310 in the second component 300. The one or more grooves may be formed in the second component 300 in any suitable manner. For example, the one or more grooves may be cut into the second component 300, may be milled into the second component 300, or may be formed with the second component (such as during production of the second component, e.g., by casting, additive manufacturing, injection molding, etc.).

[0072] According to embodiments described herein, the one or more grooves 310 in the second element 300 are capable of generating a spring effect for the second element. Additionally or alternatively, the one or more grooves provide a spring effect or enable the second element to essentially act as a spring or enable the second element to provide a spring effect (particularly during assembly of the blade shell). According to embodiments described herein, the spring effect may be generated or essentially effective in a second direction 402 that is essentially perpendicular to the first direction 401. According to some embodiments, the spring effect generated or effective in the second direction may be understood as the force exerted by the element having the spring effect essentially acting in the second direction.

[0073] In block 520, the method 500 includes placing the first element 200 and the second element 300 adjacent to each other, such as in some embodiments in a blade shell mold. Typically, when the first element 200 and the second element are placed, the first mating surface 201 of the first element 200 and the second mating surface 301 of the second element 300 face each other (e.g., Figures 5 to 9 According to some embodiments, when the first element and the second element are placed adjacent to each other, a gap may occur between the first element 200 and the second element 300.

[0074] According to some embodiments, when the first and second components are placed as far apart as possible (eg, hindered by production tolerances, geometrical deviations, irregularities of mating surfaces, temperature conditions, etc.), the first mating surface 201 and the second mating surface 301 are in abutment.

[0075] In block 530 of the method 500, the gap between the first element 200 and the second element 300 in the second direction 402 is closed by pressing the first mating surface 201 and the second mating surface 301 together. According to some embodiments, which can be combined with other embodiments described herein, bringing the first mating surface and the second mating surface into an abutting state, in particular by pressing the mating surfaces together, can be performed in block 530. Whether the abutting state can be achieved in block 520 or block 530 can depend on the placement of the first element and the second element, the material selection of the first element and the second element, the production tolerance, the production accuracy, the blade shell mold, the life of the blade shell mold, the material of the blade shell mold, the temperature, etc.

[0076] According to some embodiments, pressing the first mating surface 201 and the second mating surface 301 together may include compressing the second element and optionally the first element. Typically, the method according to some embodiments described herein may include ending the compressive force on the second element, and more typically, allowing the second element to expand (particularly due to a spring effect). In some embodiments, the expansion of the second element after compression may fill a gap between the first element and the second element.

[0077] According to some embodiments, the gap can be closed by a spring effect generated and a force applied by a spring-like acting element (i.e., a second element). Typically, closing the gap 450 includes closing the gap 450 using a spring effect provided by one or more grooves 310. It is understood that the spring effect provided by the formation of the grooves in the second element helps to close the gap in a variety of different scenarios related to the size of the elements of the blade shell. For example, since the spring effect provided by the second element can balance inappropriate sizes, the criteria for the size of the elements used in the blade shell may be less strict. Moreover, the spring effect helps to keep the elements in place by applying a corresponding force.

[0078] According to the embodiments described herein, the method for building a blade shell for a wind turbine blade and the assembly for a blade shell for a wind turbine blade improve the manufacturability of the blade shell, in particular saving work steps and reducing the criteria regarding size (which in turn may make the production process less expensive). Furthermore, the quality of the blade shell may be improved by the method and the assembly according to the embodiments described herein. By improving the quality of the blade shell, the cycle time and maintenance of the wind turbine blade may be reduced. The quality of the wind turbine blade may also be improved due to the improved strength of the blade shell produced according to the embodiments described herein, in particular when compared to existing blade shells or blade shells produced by known methods.

[0079] Exemplary embodiments of a method for building a blade shell for a wind turbine, an assembly for a blade shell for a wind turbine, and a wind turbine are described in detail above. The system and method are not limited to the specific embodiments described herein, but rather, elements of the system and / or steps of the method may be used independently of and separately from other elements and / or steps described herein.

[0080] Although specific features of various embodiments of the present invention may be shown in some drawings and not in other drawings, this is only for convenience. According to the principles of the present invention, any feature of the accompanying drawings may be combined with any feature of any other drawing to reference and / or illustrate any feature of the accompanying drawings.

[0081] Embodiments of the present invention have been described above with reference to block diagrams and flow charts of methods, assemblies, and wind turbines. It will be understood that each block in the block diagrams and flow charts, and combinations of blocks in the block diagrams and flow charts, respectively, may be implemented by various means including computer program instructions. These computer program instructions may be loaded onto a general purpose computer, a special purpose computer, or other programmable data processing device to produce a machine, such that the instructions executed on the computer or other programmable data processing device create means for implementing the functions specified in one or more flowchart blocks.

[0082] These computer program instructions may also be stored in a non-transitory computer-readable memory that can instruct a computer or other programmable data processing device to operate in a specific manner so that the instructions stored in the computer-readable memory produce an article of manufacture including computer-readable instructions for implementing the functions specified in one or more flowchart blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flowchart blocks.

[0083] Therefore, the blocks in the block diagrams and flow charts support combinations of devices for performing specified functions, combinations of steps for performing specified functions, and program instruction devices for performing specified functions. It will also be understood that each block in the block diagrams and flow charts and combinations of blocks in the block diagrams and flow charts can be implemented by a computer system based on dedicated hardware or a combination of dedicated hardware and computer instructions that performs the specified functions or steps.

[0084] Unless otherwise expressly stated, any method described herein is not intended to be interpreted as requiring that its steps be performed in a specific order. Therefore, if a method claim does not actually recite the order in which its steps should be followed, or if the claims or specification do not expressly state that the steps should be limited to a specific order, no order is intended to be inferred in any way. This applies to any possible non-express basis for interpretation, including: logical issues regarding the arrangement of steps or operational flow; plain meaning derived from grammatical organization or punctuation; the number or type of embodiments described in the specification.

[0085] This written description uses examples, including the best mode, to disclose the invention, and also to enable any person skilled in the art to practice the invention, including making and using any device or system, and performing any incorporated method. Although various specific embodiments have been disclosed above, those skilled in the art will recognize that the spirit and scope of the claims allow for equally effective modifications. In particular, mutually non-exclusive features of the above-described embodiments may be combined with each other. The patent scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art.

[0086] Reference Number Wind Turbine 100 Cabin 102 Tower 104 Rotor 106 Rotor blade 108 Hub 110 Root of rotor blade 111 Tip of rotor blade 112 Cross section 113 Shear web 114 Blade shell mold 115 First element 200 First mating surface 201 Second element 300 Second mating surface 301 Groove 310 Transverse groove 311 First Direction 401 Second Direction 402 The height of the second element 403 The first direction size of the groove 404 The second dimension of the groove is 405 Gap 450 Method 500 Methods Box 510-530

Claims

1. A blade shell assembly for a wind turbine blade shell, the blade shell assembly comprising: A first component (200) having a first mating surface (201); a second component (300) having a second mating surface (301); The first mating surface (201) and the second mating surface (301) are adapted to abut against each other in an assembled state; The second element (300) includes one or more grooves (310), which are capable of generating a spring effect to close a gap (450) between the first element (200) and the second element (300), and the gap (450) extends substantially perpendicular to the first mating surface (201) and / or the second mating surface (301).

2. A blade shell assembly according to claim 1, wherein the one or more grooves (310) extend substantially in a first direction (401) of the second element (300), the first direction extending substantially parallel to the second mating surface (301) and / or the first mating surface (201).

3. A blade shell assembly according to any one of the preceding claims, wherein a spring effect enabled to be generated by the one or more grooves (310) allows compression of the second element (300) to close the gap (450), and / or wherein a spring effect enabled to be generated by the one or more grooves (310) allows compression and expansion of the second element (300) to close the gap (450).

4. The blade shell assembly according to any one of the preceding claims, wherein the one or more grooves (310) have at least one of a substantially tapered shape, a substantially rectangular shape, a substantially serpentine shape, and a substantially open elliptical shape.

5. A blade shell assembly according to any one of the preceding claims, wherein the first element (200) is a main spar element for a blade shell, and / or wherein the second element (300) is a core element for a blade shell.

6. The blade shell assembly according to any of the preceding claims, further comprising a blade shell mould (115) for placing the first element (200) and the second element (300) in the blade shell mould (115), and in particular, for infusing resin into the first element (200) and the second element (300) in the blade shell mould (115).

7. A wind turbine blade (108) comprising a blade assembly according to any one of claims 1 to 5.

8. A method (500) for building a wind turbine blade shell comprising a first element (200) and a second element (300), the first element (200) having a first mating surface (201) and the second element (300) having a second mating surface (301), the method comprising: - forming (510) one or more grooves (310) in the second element (300), wherein the one or more grooves (310) in the second element (300) are capable of generating a spring effect for the second element (300) substantially in a direction (402) substantially perpendicular to the second mating surface (301); - placing the first element (200) and the second element (300) adjacent to each other (520), wherein the first mating surface (201) of the first element (200) and the second mating surface (301) of the second element (300) face each other; and, - Closing (530) a gap (450) between the first element (200) and the second element (300) in a direction (402) substantially perpendicular to the second mating surface (301) by pressing the first mating surface (201) and the second mating surface (301) together.

9. The method of claim 8, wherein placing the first element (200) and the second element (300) adjacent to each other comprises placing the first element (200) and the second element (300) in a blade shell mould (115).

10. The method according to any one of claims 8 to 9, further comprising infusing a resin material into the blade shell mould (115).

11. A method according to any one of claims 8 to claim 10, wherein forming one or more grooves (310) includes forming one or more grooves (310) in the second element (300) extending substantially in a first direction (401), the first direction extending substantially parallel to the second mating surface (301) and / or the first mating surface (201).

12. The method according to any one of claims 8 to 11, wherein closing the gap (450) comprises closing the gap (450) by using the spring effect generated by one or more grooves (310) in the second element (300).

13. The method according to any one of claims 8 to 12, wherein pressing the first mating surface (201) and the second mating surface (301) together comprises compressing the second element (300).

14. The method of claim 13, wherein the method further comprises ending the compressive force on the second element (300), and typically allowing the second element to expand and fill the gap (450) between the first element (200) and the second element (300).

15. The method according to any one of claims 8 to 14, wherein placing the first element (200) and the second element (300) adjacent to each other comprises placing a main spar element for a wind turbine blade shell as the first element (200) and / or placing a core material element as the second element (300).

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