Mold arrangement and method for manufacturing wind turbine blade

Abstract

A mould arrangement (8) for manufacturing a wind turbine blade (3) by infusing a resin (17) of a fibre ply (16), the mould arrangement comprising: a lower mould (9); an upper mold (10) for being arranged on the lower mold (9) such that an inner cavity (11) is formed between the molds (9, 10); and a mandrel (12) for arrangement in the inner cavity (11) wherein the mandrel (12) comprises a mandrel body (13) having a molding surface (14) and heating means (18) for providing heat at the molding surface (14). By having the mandrel with the heating means for providing heat at the molding surface, the flow of the resin can be improved, and thus the resin infusion process can be improved. In addition, a faster and better resin curing process can also be achieved.

Description

Technical Field

[0001] The present invention relates to a mold arrangement for manufacturing a wind turbine blade and a method for manufacturing a wind turbine blade. Background Art

[0002] A wind turbine blade shell is typically made of fiber-reinforced resin. To cast the shell, a fiber layup is arranged in a mold and infused with resin, for example, by a vacuum-assisted infusion process. The resin is then cured to form the blade shell. The quality of both the resin infusion and the curing process play an important role in the structural integrity of the manufactured blade. Summary of the Invention

[0003] An object of the present invention is to provide an improved mold arrangement for manufacturing a wind turbine blade and an improved method for manufacturing a wind turbine blade.

[0004] Accordingly, there is provided a mold arrangement for manufacturing a wind turbine blade by resin infusion of a fiber layup. The mold arrangement includes: a lower mold; an upper mold arranged on the lower mold such that an inner cavity is formed between the molds; and a mandrel arranged in the inner cavity. Further, the mandrel includes a mandrel body having a molding surface and a heating device for providing heat at the molding surface.

[0005] By providing the mandrel with a heating device for providing heat at the molding surface, the temperature at the molding surface can be controlled. Since the fiber layup is arranged at the molding surface, the heating device can be used to raise the temperature of the resin that wets the fiber layup. In addition, the temperature-dependent curing of the resin can be improved.

[0006] In particular, the quality of the resin infusion process depends on the uniform wetting of a dry and / or semi-dry fiber layup. Thus, voids caused by trapped air and dry areas caused by insufficient resin flow should be avoided. The viscosity of the resin, and thus the resin flow, is a function of the temperature of the resin. By controlling the resin temperature, for example, by providing heat at the molding surface of the mandrel before and / or during the resin infusion, the resin flow can be improved.

[0007] In addition, the quality of the resin curing process also depends on the temperature of the resin. The curing process of thermosetting resins (such as epoxy resins) from the liquid state in which they can be applied to the solid state in which the resin has reached (most of) its ultimate mechanical properties is characterized by gelation and vitrification (glass transition). The curing process is temperature-dependent. The higher the temperature of the resin, the faster its curing speed. The temperature of the resin depends on the ambient temperature and the temperature of the surface to which the resin is applied. Additionally, the curing of the resin itself may generate heat. In particular, the curing of epoxy resins involves an exothermic reaction in which the molecules of the epoxy mixture chemically react with each other and generate heat. The amount of heat depends on the thickness of the epoxy mass or the exposed surface area of the mixed epoxy resin. Thicker masses retain more heat, leading to a faster reaction and even more heat. By controlling the resin temperature, for example, by providing heat at the mold surface of the mandrel during and / or after the resin infusion, the curing of the resin can be improved.

[0008] A wind turbine blade is part of the rotor of a wind turbine. A wind turbine is a device that converts the kinetic energy of the wind into electrical energy. A wind turbine includes, for example, a rotor having one or more blades each connected to a hub, a nacelle including a generator, and a tower that holds the nacelle at its top. The tower of the wind turbine can be connected to the base of the wind turbine via a transition piece, such as a monopile or a concrete base in the seabed.

[0009] A wind turbine blade (e.g., its root section) is fixedly or rotatably connected to the hub. Except for the (cylindrical) root section, the wind turbine blade is aerodynamically formed. A wind turbine blade includes, for example, a pressure side (windward side) and a suction side (leeward side). The pressure side and the suction side are connected to each other at the leading edge and the trailing edge. The pressure side, the suction side, the leading edge, and the trailing edge define the airfoil of the wind turbine blade.

[0010] A wind turbine blade has a fiber-reinforced laminated structure. A wind turbine blade is manufactured by arranging fiber plies in a lower mold, an upper mold, and at the mold surface of a mandrel; infusing the fiber plies with resin; and curing the resin.

[0011] In particular, the fiber ply arranged in the lower mold is configured to become the lower shell of the blade in the cured state of the resin. Additionally, the fiber ply arranged in the upper mold is configured to become the upper shell of the blade in the cured state of the resin. The lower shell of the blade is, for example, the pressure side of the blade, and the upper shell of the blade is, for example, the suction side of the blade, or vice versa.

[0012] The mandrel may include, for example, two or more mandrel parts. The mandrel includes, for example, a leading-edge mandrel part and a trailing-edge mandrel part. In the case where the mandrel includes two or more mandrel parts, the fiber ply may also be arranged between the mandrel parts. For example, the fiber ply arranged between the leading-edge mandrel part and the trailing-edge mandrel part may be configured to become a shear web or a part of the shear web of the blade in the cured state of the resin.

[0013] The shear web connects the blade shells of the pressure side and the suction side in the internal cavity of the manufactured blade. The shear web provides shear strength for the blade.

[0014] The wind turbine blade may also include more than one shear web. In this case, the mold arrangement structure may include more than two mandrel parts, and the gap between every two adjacent mandrel parts is configured to mold one of the shear webs.

[0015] In addition to the dry or semi-dry fiber ply, core materials such as wood, balsa wood, foam, such as PET foam and / or PU foam, may be arranged in the lower mold, the upper mold, on the mandrel surface, and / or between the mandrel parts. The core material may be clamped between the fiber layers so that a fiber-reinforced resin laminate with a core structure is obtained.

[0016] Furthermore, in addition to the dry or semi-dry fiber ply, one or more precast elements may be arranged in the lower mold, the upper mold, on the mandrel surface, and / or between the mandrel parts. In this case, the precast element and the dry and / or semi-dry fiber ply may be interconnected through a resin infusion and curing process. For example, the fiber ply and at least one connection area between the precast element and the fiber ply are infused with resin to establish the connection.

[0017] The precast element includes, for example, a precast (shear) web, a precast (reinforcing) beam (such as a spar cap, a leading-edge beam, a trailing-edge beam, or another beam), a precast root section, and / or a precast tip.

[0018] In the case of adding a precast element to the fiber ply, heating the mandrel by using a heating device is particularly beneficial for improving the curing process.

[0019] The precast elements are arranged in the blade mold as already cured components. When arranged in the mold, the precast elements typically have a room temperature or even a temperature below room temperature (e.g., if they have been previously stored in an environment separate from the blade mold, and / or if the conditioning period is short). Thus, during the curing cycle, these precast elements will act as heat masses. For example, a certain percentage of the heat generated by the exothermic reaction during the curing of the resin will be transferred to the precast elements by the temperature difference. Additionally, in the region closely adjacent to the precast elements, typically only a few layers of fibers are placed to surround the precast elements and integrate them into the entire blade shell. Since the thickness and volume of the resin in this region will be low, the exothermic reaction will generate only a small amount of heat.

[0020] By using a heating device for the mandrel to provide additional heat, a complete curing cycle can be ensured and the required minimum glass transition temperature of the applied resin can be reached.

[0021] A wind turbine blade can be manufactured as a single piece. In this case, the fiber layup for the entire blade is arranged in the upper mold and the lower mold, and is infused with resin and the resin is cured.

[0022] Alternatively, a wind turbine blade can be manufactured by prefabricating two or more segments and connecting these segments to each other to form a complete blade. Connecting the prefabricated blade segments to each other can be carried out by any suitable means (such as gluing, resin infusion (laminated joints), welding, etc.) to form a complete blade.

[0023] For example, a wind turbine blade can be manufactured by prefabricating two or more longitudinal blade segments (e.g., an inner blade segment and an outer blade segment). In this case, the fiber layup for the first longitudinal blade segment is arranged in the lower mold and the upper mold, and is infused with resin and the resin is cured. Then, the fiber layup for the additional longitudinal blade segment is arranged in the upper mold and the lower mold (or additional upper and lower molds), and is infused with resin and the resin is cured.

[0024] The fiber layup arranged in the lower mold, the upper mold, and on the molding surface of the mandrel includes, for example, fibers in a dry state (i.e., without any resin), semi-dry fibers, and / or pre-impregnated fibers (prepregs).

[0025] The fiber layup includes, for example, glass fibers, carbon fibers, aramid fibers, and / or natural fibers.

[0026] In particular, the resin is infused into the fiber layup in a vacuum-assisted manner. For example, the fiber layup is covered with one or more vacuum bags, and a vacuum is generated in the space covered by the vacuum bags. Then, due to the generated vacuum, the resin is infused into this space and thus wets the fibers.

[0027] The resin includes, for example, a thermosetting resin, a thermoplastic resin, an epoxy resin, a polyurethane, a vinyl ester, and / or a polyester.

[0028] The resin is cured, for example, by applying heat by means of a heating device to a mandrel. As a result, a fiber-reinforced resin laminate is obtained.

[0029] The mandrel (or each mandrel part of several mandrel parts of the mandrel) includes a mandrel body surrounded by an outer molding surface. The mandrel body includes, for example, a core part (e.g., a steel core part) and a foam part covering the core part. The foam part includes, for example, a PU foam (PUR foam), a PET foam, and / or a PVC foam.

[0030] The mandrel (or each mandrel part of several mandrel parts of the mandrel) includes a heating device. The heating device is, for example, at least partially arranged inside the mandrel body. The heating device is, for example, at least partially arranged inside the foam part of the mandrel body.

[0031] The mold arrangement structure is in particular configured for manufacturing a blade shell of a wind turbine.

[0032] The mold arrangement structure is, for example, configured for manufacturing a wind turbine blade by resin infusion of a fiber layup and one or more precast elements.

[0033] The upper mold is arranged on the lower mold in particular such that a closed inner cavity is formed. Thus, the infusion and curing of the resin are carried out in the closed state of the lower mold and the upper mold.

[0034] Providing heat at the molding surface of the mandrel includes, for example, (e.g., actively and / or directly) heating the molding surface and / or (e.g., actively and / or directly) heating the gas volume in the gap between the molding surface of the mandrel and another molding surface of the mold arrangement structure (e.g., the molding surface of another mandrel part, the molding surface of the upper mold, and / or the molding surface of the lower mold).

[0035] The heating device is, for example, configured for providing heat at the molding surface of the mandrel by heat convection or heat conduction.

[0036] According to an embodiment, the heating device includes one or more energy lines at least partially arranged inside the mandrel body, and the one or more energy lines are configured for supplying energy towards the molding surface in order to provide heat at the molding surface.

[0037] The one or more energy lines are, for example, configured for supplying electrical energy (power) or heat towards (e.g., to) the molding surface. The one or more energy lines include, for example, one or more electrical conductors for conducting an electric current, or one or more (e.g., hollow) pipes for transporting a heating medium such as a heating fluid (e.g., a liquid or a gas).

[0038] Except for the (one or more) inlets and (one or more) outlets or connection terminals, the one or more energy lines may be, for example, entirely arranged inside the mandrel body.

[0039] According to a further embodiment, the heating device includes one or more pipes at least partially arranged inside the mandrel body, and the one or more pipes are configured to transport a heating medium towards the molding surface.

[0040] By using the one or more pipes as the one or more energy lines, heating can be achieved by supplying a heating medium via the one or more pipes.

[0041] The one or more pipes are, for example, hollow pipes.

[0042] The heating medium is in particular a heating fluid, such as a gaseous medium (e.g., air) or a liquid medium (e.g., water).

[0043] According to a further embodiment, the heating medium is a gaseous medium, and the one or more pipes include at least one outlet at the molding surface for releasing the gaseous heating medium at the molding surface.

[0044] Thus, the molding surface and / or the resin at the molding surface can be heated by generating a warm / hot gas stream (e.g., an air stream). Thus, the molding surface and / or the resin can be heated by convection.

[0045] The outlet is, for example, configured to release the gaseous heating medium into the gap between the molding surface of the mandrel and another molding surface of the mold arrangement structure. The other molding surface of the mold arrangement structure is, for example, the molding surface of the lower mold and / or the molding surface of the upper mold. In the case where the mandrel includes two or more mandrel parts, a gap can be formed between the molding surfaces of two adjacent mandrel parts.

[0046] Furthermore, the one or more pipes include, for example, an inlet for fluid connection to a gas supply device. The inlet is, for example, arranged at another surface of the mandrel, in particular at a non-molding surface of the mandrel.

[0047] In some embodiments, the mold arrangement structure includes a gas supply device fluidly connected to the inlet of the one or more pipes. The gas supply device is, for example, arranged outside the lower mold and the upper mold in a closed state, i.e., outside with respect to the inner cavity of the mold.

[0048] In some embodiments, the one or more ducts include a plurality of outlets (e.g., three or more, four or more, five or more, nine or more, and / or ten or more) disposed at the molding surface of the mandrel for releasing the heated gas at the molding surface. The plurality of outlets are, for example, arranged to be evenly distributed in the heated area of the molding surface.

[0049] In some embodiments, the heating medium is a gaseous medium, and the heating device includes one or more discharge ducts disposed at least partially inside the mandrel body. Further, each of the one or more discharge ducts includes at least one inlet at the molding surface for sucking in the gaseous heating medium. Each of the one or more discharge ducts may also include, for example, a plurality of inlets (e.g., three or more, four or more, five or more, nine or more, and / or ten or more inlets) at the molding surface. In addition, each of the one or more discharge ducts may include an outlet for discharging the gaseous heating medium to the outside of the mold. The outlets of the one or more discharge ducts are, for example, disposed at another surface of the mandrel, particularly at a non-molding surface of the mandrel.

[0050] In some embodiments, the lower mold and / or the upper mold include one or more first through-holes corresponding to the one or more (supply) duct inlets of the mandrel, and one or more second through-holes corresponding to the one or more discharge duct outlets of the mandrel.

[0051] According to a further embodiment, the heating medium is a liquid medium, the one or more ducts form at least one closed heating circuit for heating a heating zone of the mandrel, and the heating zone includes at least a part of the molding surface.

[0052] Thus, the molding surface can be heated by a liquid (e.g., water) duct circuit embedded and / or cast into the mandrel structure. The molding surface of the mandrel is heated by heat exchange with the hot liquid (e.g., water) circulating inside the circuit.

[0053] The heating zone is, for example, a three-dimensional heating zone. The heating zone is, for example, a (e.g., three-dimensional) part of the mandrel body.

[0054] According to a further embodiment, the one or more ducts include a plurality of branches, bends, and / or serpentine portions in the heating zone of the mandrel, and the heating zone includes at least a part of the molding surface.

[0055] Providing the one or more ducts disposed in the mandrel body with a plurality of branches, bends, and / or serpentine portions can heat a larger heating zone of the mandrel.

[0056] In the case of a gaseous heating medium, each branch pipe section may, for example, include at least one outlet for releasing heat at the molding surface.

[0057] The bending section and / or the serpentine section may, for example, include a plurality of S-shaped pipe sections.

[0058] According to a further embodiment, the heating device includes one or more conducting wires arranged at least partially inside the mandrel body, and an electrical heating element arranged at the molding surface of the mandrel. Further, the one or more conducting wires are electrically connected to the electrical heating element to supply power to the electrical heating element.

[0059] Thus, the molding surface can be heated by electric power. The one or more conducting wires are examples of one or more energy lines.

[0060] The one or more conducting wires are configured to be electrically connected to a power supply device.

[0061] The electrical heating element is configured to generate heat when power is supplied.

[0062] The electrical heating element is, for example, attached to the molding surface and / or exposed at the molding surface.

[0063] The heating element may, for example, have a plate shape, a pad shape, a gasket shape, and / or a blanket shape.

[0064] The heating device may, for example, include more than one electrical heating element.

[0065] In some embodiments, the mold arrangement structure includes a power supply device. The power supply device is, for example, arranged outside the lower mold and the upper mold in a closed state, that is, outside with respect to the inner cavity of the mold.

[0066] According to a further embodiment, the electrical heating element includes a resistive element, a silicon element, and / or a graphite element.

[0067] By having a resistive element, heat is generated by resistive heating. In particular, when an electric current flows through the heating element, heat is generated by Joule's law (i.e., the energy dissipated from the heating element is proportional to the resistance, current, and elapsed time of the heating element). The resistive element includes, for example, a conductive plate, a conductive grid, and / or a conducting wire (for example, arranged in a serpentine shape and / or a coil shape). The conducting wire of the resistive element may, for example, be cast into resin.

[0068] By having a silicon element, heat is generated by a silicon heater.

[0069] The silicon element includes, for example, a silicon layer, a silicon blanket, a silicon pad, and / or a silicon gasket. The silicon element includes, for example, silicone rubber. The silicon element is, for example, flexible. The silicon heating element includes, for example, an etched foil and / or a wound heating element.

[0070] Heat is generated by means of a graphite heater through a graphite element.

[0071] The graphite element includes, for example, high-purity graphite. The advantages of the graphite element are that it is highly inert and the strength of the material increases with increasing temperature. In addition, the graphite material has a low coefficient of expansion and resists degradation due to continuous thermal cycling.

[0072] According to a further embodiment, the die arrangement includes:

[0073] a control unit for controlling the amount of heat supplied by the heating device, and / or

[0074] a sensor unit for determining the temperature of the mandrel, wherein preferably the control unit is configured to control the amount of heat supplied by the heating device based on the determined temperature and / or based on a predetermined glass transition temperature of the resin.

[0075] The control unit is in particular configured to control the amount of heat provided at the molding surface of the mandrel.

[0076] The control unit is for example configured to control a gas supply device, a liquid supply device, a power supply device, a silicon heater and / or a graphite heater.

[0077] The sensor unit includes for example one or more temperature sensors. Determining the temperature of the mandrel includes for example determining the temperature of the molding surface of the mandrel, the temperature of the mandrel body and / or the temperature of one or more pipes of the heating device.

[0078] According to a further aspect, there is provided a method for manufacturing a wind turbine blade. The method includes the steps of:

[0079] a) arranging a mandrel and an upper mold on a lower mold such that the mandrel is arranged in an inner cavity formed between the molds, the mandrel including a mandrel body having a molding surface and a heating device, and a fiber ply being arranged at the molding surface,

[0080] b) providing heat at the molding surface by means of the heating device of the mandrel,

[0081] c) infusing the fiber ply with resin, and

[0082] d) curing the resin.

[0083] Step b) can be carried out before step c), during step c), after step c), before step d) and / or during step d).

[0084] Step c) can include applying a vacuum to the space between the upper mold and the lower mold and the mandrel and infusing the fiber ply with resin by means of vacuum infusion.

[0085] According to an embodiment of this further aspect, the method includes the step of determining the temperature of the mandrel, the temperature of the mandrel being determined before and / or during step b).

[0086] According to a further embodiment of this further aspect, the method includes the steps of controlling the amount of heat supplied by the heating device based on the determined temperature of the mandrel and / or based on a predetermined glass transition temperature of the resin.

[0087] Controlling the amount of heat supplied by the heating device may include determining a control scheme, a curing cycle, and / or controlling the amount of heat supplied by the heating device over time.

[0088] According to a further embodiment of this further aspect, the heating device includes one or more energy lines at least partially disposed inside the mandrel body, and in step b), heat is provided by supplying energy via the one or more energy lines towards the molding surface.

[0089] According to a further embodiment of this further aspect, the heating device includes one or more pipes and / or electrical conductors at least partially disposed inside the mandrel body. Additionally, in step b), heat is provided by:

[0090] transporting a heating medium towards the molding surface via one or more pipes,

[0091] transporting a gaseous heating medium via one or more pipes and releasing it at an outlet at the molding surface,

[0092] transporting a liquid heating medium via one or more pipes, the one or more pipes forming at least one closed heating circuit, and / or

[0093] supplying power to an electric heating element disposed at the molding surface via one or more electrical conductors.

[0094] According to a further embodiment of this further aspect,

[0095] in step a), a precast element is disposed at the molding surface and in contact with the fiber ply,

[0096] in step b), heat is provided at a heating region of the molding surface, the precast element being disposed adjacent to the heating region, and

[0097] in step c), the fiber ply and at least one connection region between the precast element and the fiber ply are infused with resin.

[0098] The corresponding entity (e.g., a control unit) can be implemented in hardware and / or software. If the entity is implemented in hardware, it can be embodied as a device, e.g., a computer or a processor or a part of a system such as a computer system. If the entity is implemented in software, it can be embodied as a computer program product, a function, a routine, program code, or an executable object.

[0099] According to a further aspect, the invention relates to a computer program product comprising program code for performing at least the steps of controlling the amount of heat as described above when run on at least one computer.

[0100] A computer program product (such as a computer program device) can be embodied as a memory card, a USB stick, a CD-ROM, a DVD, or a file that can be downloaded from a server in a network. For example, this file can be provided by transmitting a file comprising the computer program product from a wireless communication network.

[0101] The embodiments and features described with reference to the die arrangement structure of the invention are applied to the method of the invention with necessary modifications.

[0102] Further possible embodiments or alternative solutions of the invention also cover combinations of features described above or below with respect to the embodiments that are not explicitly mentioned herein. A person skilled in the art can also add individual or isolated aspects and features to the most basic form of the invention. Description of the Drawings

[0103] In conjunction with the drawings, further embodiments, features, and advantages of the invention will become apparent from the following description and the dependent claims, wherein:

[0104] Figure 1 Shows a wind turbine according to an embodiment;

[0105] Figure 2 Shows in a cross-sectional view a die arrangement for manufacturing Figure 1 a blade of a wind turbine according to an embodiment;

[0106] Figure 3 Shows in a cross-sectional view a further embodiment of a die arrangement for manufacturing Figure 1 a blade of a wind turbine;

[0107] Figure 4 Shows a perspective view of a mandrel part of a mandrel of a die arrangement according to an embodiment Figure 3 of;

[0108] Figure 5 Shows a view similar to Figure 4 but the heating device of the mandrel includes a discharge duct;

[0109] Figure 6 According to another embodiment, Figure 3 A perspective view of a mandrel portion of a mandrel of a mold arrangement;

[0110] Figure 7 According to another embodiment, Figure 3 A perspective view of a mandrel portion of a mandrel of a mold arrangement; and

[0111] Figure 8 Shown is a diagram for manufacturing Figure 1 Flowchart of a method for producing a blade for a wind turbine.

[0112] In the drawings, like reference numbers indicate similar or functionally equivalent elements unless otherwise indicated. DETAILED DESCRIPTION

[0113] Figure 1 A wind turbine 1 according to an embodiment is shown. The wind turbine 1 comprises a rotor 2 having one or more blades 3 connected to a hub 4. The hub 4 is connected to a generator (not shown) arranged inside a nacelle 5. During operation of the wind turbine 1, the blades 3 are driven to rotate by the wind, and the kinetic energy of the wind is converted into electrical energy by the generator in the nacelle 5. The nacelle 5 is arranged at the upper end of a tower 6 of the wind turbine 1. The tower 6 stands on a foundation 7 such as a monopile or a concrete foundation. The foundation 7 is connected to and / or hammered into the ground or the seabed.

[0114] In the following, reference Figures 2 to 8 An improved mould arrangement and method for manufacturing a wind turbine blade 3 is described.

[0115] Figure 2 Shown in cross section for manufacturing Figure 1 A mold arrangement structure 8 is provided for one of the wind turbine blades 3. The mold arrangement structure 8 comprises: a lower mold 9 and an upper mold 10. Figure 2 In the closed state of the mold arrangement 8 shown in , the upper mold 10 is arranged on the lower mold 9 so that an inner cavity 11 is formed. The mold arrangement 8 also includes a mandrel 12, which is arranged inside the cavity 11 formed by the lower mold 9 and the upper mold 10. Therefore, the mandrel 12 is a mold core. The mandrel 12 includes a mandrel body 13 surrounded by an outer surface 14, which is the molding surface 14 of the mandrel 12.

[0116] In the closed state of the mould arrangement 8 , a gap 15 is formed between the lower mould 9 and the upper mould 10 and the mandrel 12 for moulding the shell of the blade 3 .

[0117] The reference sign V denotes the vertical direction V of the molds 9, 10 in the closed state of the molds 9, 10 (i.e., in the closed state of the mold arrangement structure 8). During the molding process, the vertical direction V points particularly from the lower mold 9 to the upper mold 10.

[0118] The gap 15 is configured to accommodate the fiber layup 16 for the lower and upper shells of the blade 1 to be molded.

[0119] As Figure 2 illustrated, the fiber layup 16 is infused with the resin 17. Then, the resin 17 is cured to form a fiber-reinforced resin laminate (e.g., the lower and upper blade shells).

[0120] Furthermore, the mandrel 12 includes heating means 18 for providing heat at the molding surface 14. By using the heating means 18, the molding surface 14 of the mandrel 12 and / or the gas volume in the gap 15 can be actively heated. Thus, the heating means 18 can be used to improve the temperature-dependent resin infusion process and / or the temperature-dependent curing process of the resin 17. For example, by heating the molding surface 14 of the mandrel 12 before or during the infusion of the liquid resin 17, the temperature of the resin 17 can be increased, and thus, the viscosity of the resin 17 is reduced. Therefore, the flow of the resin 17 can be improved. In addition, by heating the molding surface 14 of the mandrel 12 after the resin infusion, the curing process (gelation, vitrification) of the resin 17 can be accelerated.

[0121] Figure 3 Shows a further embodiment of the mold arrangement structure 8' for manufacturing Figure 1 one of the wind turbine blades 3. Similar to the mold arrangement structure 8 ( Figure 2 ), the mold arrangement structure 8' ( Figure 3 ) includes: a lower mold 9' and an upper mold 10', which form an inner cavity 11' in the closed state. The mold arrangement structure 8' also includes a mandrel 12' disposed inside the cavity 11'. In contrast to the Figure 2 mold arrangement structure 8, Figure 3 the mandrel 12' in the embodiment of

[0122] includes two mandrel parts 12a, 12b (a first mandrel part 12a, a second mandrel part 12b). It should be noted that in other embodiments, although not shown in the drawings, the mold arrangement structure may also include more than two mandrel parts.

[0123] In the closed state of the mould arrangement 8 ′, a gap 15 ′ is formed between the lower mould 9 ′ and the upper mould 10 ′ and the mandrel parts 12 a , 12 b for moulding the upper and lower shells of the blade 3 .

[0124] Furthermore, in the closed state of the mould arrangement 8', a further gap 19 is formed between the first mandrel part 12a and the second mandrel part 12b for moulding the shear web of the blade 3. The further gap 19 is defined by the mating outer moulding surfaces 14a and 14b of the first mandrel part 12a and the second mandrel part 12b, respectively. In the closed state of the mould arrangement 8', the further gap 19 extends in the vertical direction V of the moulds 9', 10'.

[0125] The gap 15' is configured to receive fiber layups 16' for molding the lower and upper shells of the blade 3. The further gap 19 is configured to receive fiber layups 20 and precast web elements 21, for example, for molding the shear webs of the blade 3. Figure 3 Also shown exemplarily are two precast beams 22 arranged in the lower mold 9' and the upper mold 10', respectively. The two precast beams 22 are configured to become spar caps of the blade 3 in the manufactured state of the blade 3, which are connected to the shear web (see precast web element 21).

[0126] The fiber layers 16', 20 are infused with resin 17 ( Figure 2 Although not shown in the drawings, a vacuum bag may be provided so that it covers and surrounds the fiber lay-ups 16', 20. Furthermore, the resin 17 may be infused in a vacuum-assisted manner.

[0127] When using precast elements 21 , 22 , the fiber lay-ups 16 ′, 20 and at least one connection region R of the precast elements 21 , 22 to the fiber lay-ups 16 ′, 20 are infused with resin 17 .

[0128] The resin 17 is then cured to form the fibre reinforced resin laminate (ie the lower and upper shells, the shear webs and the connections of the shear webs to the spar caps and the lower and upper shells).

[0129] To improve the resin infusion and / or curing process, Figure 3 The mandrel 12' of the embodiment of the embodiment further comprises a heating device 18' for providing heat at the molding surface of the mandrel 12'. For example, each of the mandrel portions 12a, 12b of the mandrel 12' comprises a heating device 18a, 18b. Figure 3In the illustrated example, the heating devices 18a, 18b are arranged such that heat can be provided at the mating molding surfaces 14a, 14b of the mandrel portions 12a, 12b. Accordingly, heat can be provided near the precast web element 21. This is particularly advantageous since the precast web element 21 will act as a heat mass during the curing process and the amount of heat released generated in the region of the precast web element 21 will be small.

[0130] Although Figure 3 not shown in the figures, the mandrel 12' (i.e., the mandrel portions 12a, 12b) may also include heating devices (similar to the heating device 18') arranged close to the precast beam 22, which is configured to become the spar cap of the blade 3. In this case, heat can also be provided at the molding surfaces 23a, 23b of the mandrel portions 12a, 12b in order to improve the curing process near the precast beam 22. It should be noted that in Figure 3 the figures, for purposes of illustration, only the molding surfaces 23a, 23b of the mandrel portions 12a, 12b close to the lower precast beam 22 are denoted by reference numerals.

[0131] In addition, the mandrel 12' (or Figure 2 the mandrel 12 in

[0132] may include additional heating devices other than those shown in the figures, or the shown heating devices 18, 18' may be arranged at other portions of the molding surfaces 14, 14', 23a, 23b. Figures 4 to 7 In Figure 4 , Figure 5 heating devices 118a, 218a, 318a according to the first to third embodiments are shown. In the first embodiment, heat is provided based on a heated gas such as heated air ( Figure 6 ). In the second embodiment, heat is provided based on a heated liquid such as heated water circulating in a heating circuit ( Figure 7 ). In the third embodiment, heat is provided based on an electrically heated heating element (

[0133] The heating devices 118a, 218a, 318a according to the first to third embodiments each include one or more energy lines 25, 35, 45 at least partially arranged inside the mandrel bodies 113a, 213a, 313a. In addition, the one or more energy lines 25, 35, 45 are configured to supply energy (e.g., heated gas, heated liquid or power) towards the molding surfaces 114a, 214a, 314a for providing heat at the molding surfaces 114a, 214a, 314a.

[0134] In Figures 4 to 7 exemplarily shown is something similar to Figure 2The heating device 118a, 218a, 318a of the mandrel portion 112a, 212a, 312a of the mandrel portion 12a. However, in the following description, Figures 4 to 7 The described heating devices 118a, 218a, 318a may be arranged at any molding surface 14, 14a, 14b, 23a, 23b of any mandrel 12, 12' and / or any mandrel portion 12a, 12b described herein.

[0135] Figure 4 A heating device 118a according to a first embodiment is shown, in which heat is provided based on a heated gas 24 (eg heated air). The heating device 118a comprises one or more ducts 25 for conveying the heated gas 24 towards the molding surface 114a. Figure 4 In the embodiment, one pipe 25 is shown by way of example, which has several branches 26 and branch pipe parts (without reference numerals). However, the heating device 118a may also include more than one pipe 25.

[0136] One or more tubes 25 are at least partially disposed within the mandrel body 113a. Figure 4 In the embodiment, except for the inlet 26 and the outlet 27, the pipeline 25 is completely arranged inside the spindle body 113a. In particular, the pipeline 25 includes an inlet 26 for fluid connection with a gas supply device 28 (gas heating device 28). The inlet 26 is, for example, arranged at another surface 29 (for example, a non-molding surface 29) of the spindle 112a. The gas supply device 28 includes, for example, a heating unit for heating the gas and a blower unit for providing the gas pressure required for transporting the gas 24 through the pipeline 25. The gas supply device 28 is arranged outside the lower mold 9' and the upper mold 10' in a closed state, that is, relative to the inner cavity 11' ( Figure 3 ) on the outside.

[0137] Furthermore, the one or more ducts 25 include at least one outlet 27 at the molding surface 114a for releasing the heated gas 24 at the molding surface 114a. Figure 4 In the example of , the duct 25 comprises a plurality of outlets 27; nine outlets 27 are exemplarily shown. The plurality of outlets 27 are arranged, for example, to be evenly distributed in the heating region 30 of the molding surface 114a.

[0138] like Figure 5 As shown in , the heating device 118a may optionally include one or more exhaust conduits 31 disposed at least partially within the interior of the mandrel body 113a. Figure 5 In FIG. 1 , for example, one exhaust duct 31 is shown. Each of the one or more exhaust ducts 31 includes at least one inlet 32 at the molding surface 114 a for sucking in the gas 24.Figure 5 Among them, four inlets 32 are exemplarily shown. In addition, each of the one or more discharge pipes 31 includes an outlet 33 for discharging the gas 24 to the outside of the molds 9' and 10'. The outlet 33 is arranged, for example, at another surface 29 of the mandrel 112a. Optionally, the outlet 33 can be fluidly connected to the gas supply device 28.

[0139] Figure 6 The heating device 218a according to the second embodiment is illustrated, in which heat is provided based on the heated liquid 34 (for example, heated water). The heating device 218a includes one or more pipes 35 for transporting the heating liquid 34 towards the molding surface 214a. The one or more pipes 35 form at least one closed heating circuit Z. In Figure 6 Among them, one pipe 35 forming one closed heating circuit Z is exemplarily shown. However, the heating device 218a can also include more than one pipe 35 and / or form more than one closed heating circuit Z.

[0140] The one or more pipes 35 are at least partially arranged inside the mandrel body 213a. In Figure 6 Among them, except for the inlet 36 and the outlet 37, the pipe 35 is completely arranged inside the mandrel body 213a. In particular, the pipe 35 includes an inlet 36 for fluid connection with the liquid supply device 38 (liquid heating device 38). The inlet 36 is arranged, for example, at another surface 39 (for example, non-molding surface 39) of the mandrel 212a. The liquid supply device 38 includes, for example, a heating unit for heating the liquid 34 and a pumping unit for providing the required flow rate for transporting the liquid 34 through the pipe 35. The liquid supply device 38 is arranged outside the lower mold 9' and the upper mold 10' in a closed state ( Figure 3 ), that is, outside with respect to the inner cavity 11' of the lower mold 9' and the upper mold 10'.

[0141] The pipe 35 includes, for example, a plurality of bent portions 40 and / or serpentine portions 41 in order to heat a larger heating zone 42 of the mandrel body 213a. The heating zone 42 particularly includes a part of the molding surface 214a. The part of the molding surface 214a that is a part of the heating zone 42 is also referred to as the heating region 43 of the molding surface 214a.

[0142] Figure 7 The heating device 318a according to the third embodiment is illustrated, in which heat is provided based on the electrically heated heating element 44. The heating device 318a includes one or more conductive wires 45 for supplying power I (current) to the heating element 44. In Figure 7 Among them, one heating element 44 is exemplarily shown. However, the heating device 318a can also include more than one heating element 44.

[0143] The conductive wire 45 includes a terminal 46 for electrical connection to a power supply device 48. The terminal 46 is arranged, for example, at an additional (e.g., non-molded) surface 47 of the mandrel portion 312a. The power supply device 48 is arranged outside the molds 8', 9' and the cavity 11'( Figure 3 ).

[0144] The heating element 44 is attached to the molding surface 314a. In particular, the heating element 44 is exposed at the molding surface 314a.

[0145] The heating element 44 is configured to convert electric current into heat. As Figure 7 shown in the illustration, the heating element 144 includes, for example, a resistive heating element 49. The resistive heating element 49 includes, for example, one or more conductive wires 49. The one or more conductive wires 49 are, for example, cast into a resin 50. Additionally, the heating element 244 may include, for example, a silicon layer 51 and / or a silicon heater 52. Additionally, the heating element 244 may include, for example, a graphite element 53 and / or a graphite heater 54.

[0146] Optionally, the mold arrangement structures 8, 8'( Figure 2 , Figure 3 ) may further include control units 55, 56, 57 for controlling the amount of heat provided by the heating devices 18, 18', 118a, 218a, 318a( Figures 4 to 7 ). The control units 55, 56, 57 may, for example, determine the desired temperature of the molding surfaces 14, 14', 114a, 214a, 314a and / or the desired temperature of the gas volume in the gaps 15, 15', 19( Figure 3 ). The control units 55, 56, 57 send, for example, control signals A, B, C to the respective supply units 28, 38, 48 for controlling the supply of the heated gas 24, the heated liquid 34 or the power I to the heating devices 18, 18', 118a, 218a, 318a of the mandrel (portion) 12, 12', 112a, 212a, 312a.

[0147] The control units 55, 56, 57 may, for example, determine the amount of desired heat to be provided by the heating devices 18, 18', 118a, 218a, 318a based on a predetermined glass transition temperature of the resin 17. The control units 55, 56, 57 may, for example, determine a control scheme (control recipe) including different time periods with different amounts of heat provided and / or different time periods with different time evolutions of the heat provided.

[0148] As Figure 6As shown exemplarily in the figure for the heating device 218a, the heating device 18, 18', 118a, 218a, 318a may further include a sensor unit 58 for determining the temperature of the mandrel (part) 12, 12', 12a, 12b, 112a, 212a, 312a. The sensor unit 58 may include one or more sensors 59, 60. Figure 6 In the example of FIG. 5 , one sensor 59 is arranged in the heating zone 42 of the mandrel body 213 a. Another sensor 60 is arranged in the pipe 35 .

[0149] In the case where the heating device 18, 18', 118a, 218a, 318a includes a sensor unit 58 for determining the temperature of the core shaft (part) 12, 12', 12a, 12b, 112a, 212a, 312a, the control unit 55, 56, 57 can be configured to control the amount of heat supplied by the heating device 18, 18', 118a, 218a, 318a based on the determined temperature and optionally also based on a predetermined glass transition temperature of the resin 17.

[0150] Figure 8 A diagram is shown for manufacturing a Figure 1 Flow chart of a method for wind turbine 1 having a blade 3 .

[0151] In a first step S1 of the method, a lower mold 9 , 9 ′ is provided.

[0152] In the second step S2 of the method, the fiber layup 16, 16' is arranged in the lower mold 9, 9'. Optionally, a precast beam 22 ( Figure 3 ) are arranged in the lower mold 9, 9'.

[0153] In a third step S3 of the method, the mandrel 12, 12' (e.g. a plurality of mandrel parts 12a, 12b) is arranged on the lower mold 9, 9'. In case there are several mandrel parts 12a, 12b, in step S3, the fiber layup 20 and / or a precast web element 21 ( Figure 3 ) are arranged in the gap 19 between the mandrel parts 12a, 12b.

[0154] In a fourth step S4 of the method, the fiber layup 16, 16' is arranged on top of the mandrel 12, 12' (eg, on top of the plurality of mandrel sections 12a, 12b). Optionally, a precast beam 22 ( Figure 3 ) are arranged on top of the mandrel 12, 12'.

[0155] In the fifth step S5 of the method, the upper molds 10, 10' are arranged on the mandrels 12, 12' and on the lower molds 9, 9'.

[0156] In the sixth step S6 of the method, the fiber plies 16, 16', 20 are infused with the resin 17.

[0157] In the seventh step S7 of the method, optionally, the temperature of the mandrels 12, 12' is determined by means of the sensor unit 58.

[0158] In the eighth step S8 of the method, optionally, the amount of heat provided by the heating devices 18, 18', 118a, 218a, 318a is controlled. This control is based, for example, on the temperature of the mandrels 12, 12' determined in step S7 and / or on the predetermined glass transition temperature of the resin 17 used.

[0159] In the ninth step S9 of the method, heat is provided at the molding surfaces 14, 14', 14a, 14b, 23a, 23b, 114a, 214a, 314a of the mandrels 12, 12' by using the heating devices 18, 18', 118a, 218a, 318a.

[0160] Step S9 can be carried out before and / or during step S10.

[0161] In the tenth step S10 of the method, the resin 17 is cured.

[0162] By providing heat at the molding surfaces 14, 14', 14a, 14b, 23a, 23b, 114a, 214a, 314a of the mandrels 12, 12' of the mold arrangement structure 8, 8' before and / or during the curing of the resin 17 in step S10, the gelation and vitrification of the resin 17 can be accelerated. Thus, the solid state of the resin 17 can be achieved efficiently and reliably. This is also the case even in the presence of the precast elements 21, 22 acting as heat mass blocks.

[0163] It should be noted that, in addition to or instead of before and / or during step S10, the heating step S9 can also be carried out before and / or during the step S6 of infusing the resin 17.

[0164] By providing heat at the molding surfaces 14, 14', 14a, 14b, 23a, 23b, 114a, 214a, 314a of the mandrels 12, 12' of the mold arrangement structure 8, 8' before and / or during the infusion of the resin 17 in step S6, the viscosity of the resin 17 can be reduced, resulting in better resin flow. Thus, dry spots are avoided and the wetting of the dry or semi-dry fiber plies 16, 16', 20 is improved.

[0165] Although the invention has been described in terms of preferred embodiments, modifications are possible in all embodiments and will be apparent to those skilled in the art.

Claims

1. A tooling arrangement (8) for manufacturing a wind turbine blade (3) by resin infusion (17) into a fiber layup (16), the tooling arrangement comprising: Lower die (9); Upper die (10), the upper die (10) being arranged on the lower die (9) such that an inner cavity (11) is formed between the dies (9, 10); and a mandrel (12), the mandrel (12) being arranged in the inner cavity (11), wherein the mandrel (12) includes a mandrel body (13) having a molding surface (14) and heating means (18) for providing heat at the molding surface (14).

2. The mold layout structure according to claim 1, wherein, The heating means (118a, 218a, 318a) includes one or more energy lines (25, 35, 45) at least partially arranged inside the mandrel body (113a, 213a, 313a), and the one or more energy lines (25, 35, 45) are configured to supply energy (24, 34, I) towards the molding surface (114a, 214a, 314a) for providing heat at the molding surface (114a, 214a, 314a).

3. The mold arrangement structure according to claim 1 or 2, wherein, The heating means (118a, 218a) includes one or more pipes (25, 35) at least partially arranged inside the mandrel body (113a, 213a), and the one or more pipes (25, 35) are configured to transport a heating medium (24, 34) towards the molding surface (114a, 214a).

4. The mold arrangement structure according to claim 3, wherein, The heating medium (24) is a gaseous medium, and the one or more pipes (25) include at least one outlet (27) at the molding surface (114a) for releasing the gaseous heating medium (24) at the molding surface (114a).

5. The mold arrangement structure according to claim 3, wherein, The heating medium (34) is a liquid medium, the one or more pipes (35) form at least one closed heating circuit (Z) for heating a heating zone (42) of the mandrel (214a), and the heating zone (42) includes at least a portion (43) of the molding surface (214a).

6. The mold arrangement structure according to one of claims 3 to 5, wherein, The one or more pipes (25, 35) include a plurality of branches (26), bends (40) and / or serpentine portions (41) in the heating zones (30, 42) of the mandrel (112a, 212a), and the heating zones (30, 42) include at least a portion (43) of the molding surface (114a, 214a).

7. The mold arrangement structure according to claim 1 or 2, wherein The heating means (318a) includes one or more conductive wires (45) at least partially arranged inside the mandrel body (313a), and an electrical heating element (44) arranged at the molding surface (314a) of the mandrel (312a), and wherein the one or more conductive wires (45) are electrically connected to the electrical heating element (44) for supplying power (I) to the electrical heating element (44).

8. The mold arrangement structure according to claim 7, wherein, The electrical heating element (144, 244, 344) includes a resistive element (49), a silicon element (51) and / or a graphite element (53).

9. The die arrangement according to one of claims 1 to 8, comprising: A control unit (55, 56, 57) for controlling the amount of heat supplied by the heating device (118a, 218a, 318a), and / or A sensor unit (58) for determining the temperature of the mandrel (112a, 212a, 312a), wherein preferably, the control unit (55, 56, 57) is configured to control the amount of heat supplied by the heating device (118a, 218a, 318a) based on the determined temperature and / or based on a predetermined glass transition temperature of the resin (17).

10. A method for manufacturing a wind turbine blade (3), comprising the steps of: a) Arranging (S1, S3, S5) a mandrel (12) and an upper mold (10) on a lower mold (9) such that the mandrel (12) is arranged in an inner cavity (11) formed between the molds (9, 10), the mandrel (12) including a mandrel body (13) having a molding surface (14) and a heating device (18), and arranging (S2, S4) a fiber ply (16) at the molding surface (14), b) Providing (S9) heat at the molding surface (14) by the heating device (18) of the mandrel (12), c) Infusing (S6) the fiber ply (16) with a resin (17), and d) Curing (S10) the resin.

11. The method according to claim 10, comprising the step of determining (S7) the temperature of the mandrel (12), the temperature of the mandrel (12) being determined before and / or during step b).

12. The method according to claim 10 or 11, comprising the step of: controlling (S8) the amount of heat supplied by the heating device (18) based on the determined temperature of the mandrel (12) and / or based on a predetermined glass transition temperature of the resin (17).

13. The method according to one of claims 10 to 12, wherein, The heating device (118a, 218a, 318a) includes one or more energy lines (25, 35, 45) at least partially arranged inside the mandrel body (113a, 213a, 313a), and in step b), heat is provided by supplying energy (24, 34, I) via the one or more energy lines (25, 35, 45) towards the molding surface (114a, 214a).

14. The method according to any one of claims 10 to 13, wherein The heating device (118a, 218a, 318a) includes one or more pipes (25, 35) and / or electrical conductors (45) at least partially arranged inside the mandrel body (113a, 213a, 313a), and In step b), heat is provided by: Transporting a heating medium (24, 34) towards the molding surface (114a, 214a) through the one or more pipes (25, 35), Transporting a gaseous heating medium (24) through the one or more pipes (25) and releasing it at an outlet (27) at the molding surface (114a), Transporting a liquid heating medium (34) through the one or more pipes (35), the one or more pipes (35) forming at least one closed heating circuit (Z), and / or Supplying power (I) to an electric heating element (44) arranged at the moulding surface (314a) through the one or more electrical conductors (45).

15. The method according to one of claims 10 to 14, wherein in step a), precast elements (21, 22) are arranged at the moulding surface (14a, 14b, 23a, 23b, 114a, 214a, 314a) and are in contact with the fibre ply (16, 16', 20), in step b), heat is provided at a heating zone (30, 43) of the moulding surface (14a, 14b, 23a, 23b, 114a, 214a, 314a), the precast elements (21, 22) being arranged adjacent to the heating zone (30, 43), and in step c), the fibre ply (16, 16', 20) and at least one connection zone (R) between the precast elements (21, 22) and the fibre ply (16, 16', 20) are infused with resin (17).

Images