Method and mould arrangement for manufacturing wind turbine blade

Abstract

A method for manufacturing a wind turbine blade (3), comprising: arranging (S3, S4) first and second mandrels (12, 13) and an upper mould (10) on a lower mould (9) wherein fibre plies (21, 22) are arranged in the lower mould (9), in the upper mould (10) and between the first and second mandrels (12, 13), respectively for moulding a lower shell (17), an upper shell (18) and a shear web (19) of the blade (3), and wherein the fibre plies (21, 22) are arranged in the lower mould (9), in the upper mould (10) and between the first and second mandrels (12, 13), respectively, and wherein the fibre plies (21, 22) are arranged in the lower mould (9) and between the first and second mandrels (12, 13). The first and / or second mandrel (12, 13) comprises one or more sensors (26) arranged at the outer surface (20a-20d) thereof and adjacent to the fibrous ply (22) provided for moulding the shear web (19), infusing (S6) the fibrous ply (21, 22) with a resin (25) and curing (S7) the resin (25), and monitoring (S8) the infusion and / or curing of the resin (25) by means of the one or more sensors (26).

Description

Technical Field

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

[0002] One way to generate more energy with a wind turbine under given wind conditions is to increase the size of the blades. However, with increasingly larger blade sizes, wind turbine blades become increasingly difficult to manufacture.

[0003] Currently, many wind turbine blades are made by prefabricating the components of the blade separately (e.g., the pressure side shell and the suction side shell), and gluing the components to each other. The components are prefabricated, for example, by infusing a composite material (e.g., fiberglass with a resin) and allowing the resin to cure. However, the gluing process has many disadvantages. For example, it is challenging to make the glue line have sufficient strength and durability.

[0004] In another method disclosed in EP 1310351 A1, the blade is manufactured by loading the composite material for the entire blade or for the longitudinal blade section into a mold and infusing the resin into the closed mold by vacuum-assisted means and curing the resin. Thus, gluing of the leading and trailing edges is avoided. However, monitoring the resin infusion and curing process is difficult with this method because it is carried out in a closed mold. Summary of the invention

[0005] It is an object of the present invention to provide an improved method for manufacturing a wind turbine blade.

[0006] Accordingly, a method for manufacturing a wind turbine blade is provided. The method comprises the following steps:

[0007] a) arranging first and second mandrels and an upper mould on a lower mould, wherein a fibre layup is arranged in the lower mould, the upper mould and between the first and second mandrels for moulding a lower shell, an upper shell and a shear web of the blade, respectively, and wherein the first and / or second mandrel comprises one or more sensors arranged at an outer surface thereof and adjacent to the fibre layup arranged for moulding the shear web,

[0008] b) applying a vacuum to the space between the upper and lower moulds and the mandrel,

[0009] c) infusing the fiber layup with resin and curing the resin, and

[0010] d) Monitoring the infusion and / or curing of the resin by means of the one or more sensors.

[0011] The upper mold is particularly arranged on the lower mold so that a closed internal cavity is formed. The first and second mandrels are particularly arranged in the internal cavity. Therefore, the infusion and curing of the resin are carried out in the closed state of the lower and upper molds. This hinders the visual inspection of the resin flow and the curing process of the resin. However, with the help of one or more sensors, real-time monitoring of the resin infusion and / or curing process is still possible despite the molding being carried out in the closed mold.

[0012] Furthermore, having one or more sensors arranged adjacent to a fiber layup which is configured to become a shear web in the resin cured state, it is possible to monitor the resin transfer molding in the region of the shear web.

[0013] The quality of the manufactured fiber reinforced laminates depends to a large extent on several parameters related to the infusion and curing process, such as the temperature and pressure of the resin. For example, the temperature-dependent viscosity of the resin affects the flow of the resin through the fibers.

[0014] The one or more sensors are configured to acquire sensor data of one or more parameters (e.g., physical parameters) that affect the infusion and / or curing process. The sensor data may include measured physical quantities of the first and / or second mandrels, of the fiber layup (e.g., a fiber layup arranged between the mandrels), and / or of resin wetting the fiber layup (e.g., resin flowing in the gap between the first and second mandrels).

[0015] By monitoring parameters influencing the infusion and / or curing process with one or more sensors, the resin infusion and / or curing process can be controlled. As a result, the quality of the manufactured wind turbine blade can be improved. For example, a better uniform distribution of the resin throughout the fibers can be achieved. For example, some parts of the fibers can be better prevented from remaining dry, i.e. without resin. Another example is that the generation of enclosed air bubbles in the laminate can be reduced. As a result, the strength and durability of the laminate structure can be improved.

[0016] 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 wind into electrical energy. A wind turbine comprises, for example, a rotor (having one or more of the blades each connected to a hub), a nacelle (including a generator), and a tower (holding the nacelle at its top). The tower of a wind turbine may be connected to the foundation of the wind turbine, such as a monopile or concrete foundation in the seabed, via a transition piece.

[0017] A wind turbine blade, for example its root section, is fixedly or rotatably connected to a hub. Apart from the (cylindrical) root section, the wind turbine blade is aerodynamically formed. A wind turbine blade comprises, for example, a pressure side (upwind side) and a suction side (downwind side). The pressure side and the suction side are connected to each other at a leading edge and a trailing edge. The pressure and suction sides and the leading and trailing edges define the airfoil of the wind turbine blade.

[0018] A wind turbine blade has a fiber reinforced laminate structure. The wind turbine blade is manufactured by arranging fiber layups in lower and upper molds and between mandrels, infusing the fiber layups with resin, and curing the resin.

[0019] In particular, the fiber layup arranged in the lower mold is configured to become the lower shell of the blade in the cured state of the resin. Furthermore, the fiber layup 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.

[0020] Furthermore, the fiber layup arranged between the first and second mandrels is configured to become a shear web of the blade in the cured state of the resin. In addition to the dry and / or semi-dry fiber layup, the fiber layup arranged between the first and second mandrels may also include one or more pre-cast elements. In this case, the pre-cast elements and the dry and / or semi-dry fiber layup may be connected to each other by a resin infusion and curing process. The shear web connects the blade shells on the pressure side and the suction side in the internal cavity of the manufactured blade. The shear web provides shear strength to the blade.

[0021] The wind turbine blade may also comprise more than one shear web. In this case, the mould arrangement may comprise more than two mandrels, the gap between each adjacent mandrel being configured to mould one of the shear webs.

[0022] Wind turbine blades can be manufactured as a single piece. In this case, the fiber layup for the entire blade is arranged in upper and lower molds and between mandrels, and infused with resin and cured.

[0023] Alternatively, the wind turbine blade may be manufactured by pre-manufacturing two or more longitudinal blade segments (e.g., an inner blade segment and an outer blade segment) and connecting the longitudinal blade segments to each other to form a complete blade. In this case, the fiber layup for the first longitudinal blade segment is arranged in the lower and upper molds and between the mandrels, and is infused with resin and cured. Then, the fiber layup for the other longitudinal blade segment is arranged in the upper and lower molds and between the mandrels (or in other upper and lower molds and between other mandrels), and is infused with resin and cured. After pre-manufacturing two or more longitudinal blade segments, the longitudinal blade segments are connected to each other by any suitable method to form a complete blade.

[0024] The fiber layup arranged in the lower and upper molds and between the mandrels comprises, for example, fibers in a dry condition (ie without any resin), semi-dry fibers, pre-impregnated fibers (prepregs) and / or pre-cast elements.

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

[0026] The fiber layup may comprise a fiber core material, such as wood, balsa, PET foam and / or PVC foam. The core material may be sandwiched between the fiber layers so that a fiber reinforced resin laminate having a core structure is obtained.

[0027] Furthermore, one or more reinforcement beams may be arranged in the mould and connected to the fibre lay-up through a resin infusion and curing process.

[0028] The resin is infused into the fiber layup in particular in a vacuum-assisted manner. For example, the fiber layup is covered with one or more vacuum bags and a vacuum is created in the space covered by the vacuum bag. The resin is then infused into this space due to the vacuum created and thereby wets the fibers.

[0029] The resin includes, for example, a thermosetting resin, a thermoplastic resin, an epoxy resin, a polyurethane, a vinyl ester, and / or a polyester.

[0030] The resin may be cured, for example by heating.The result is a fiber reinforced resin laminate.

[0031] Monitoring the process of infusing the fiber layup with resin and / or curing the resin based on the sensor data is performed, for example, by means of a human machine interface (HMI), such as a display unit of a computer, laptop, tablet, mobile phone and / or augmented reality device (AR device, such as AR glasses). Monitoring the infusion and / or curing process includes, for example, checking the displayed sensor data. It may also include detecting deviations of the displayed sensor data from a desired state. It may include an alarm system to indicate such deviations.

[0032] The first and / or second mandrel each comprises, for example, a core portion and a foam portion covering the core portion. The foam portion comprises, for example, PU foam (PUR foam), PET foam and / or PVC foam. The core portion comprises, for example, a supporting structure (e.g. made of wood). The core portion may comprise an internal cavity. In addition, the first and / or second mandrel each may comprise an additional layer (e.g. a carbon layer) disposed between the core portion and the foam portion.

[0033] The one or more sensors are, for example, each fixed at the outer surface of the first and / or second mandrel. The fixing of the sensors can be achieved by applying an adhesive or by mechanical fixing (eg screw fixing, clamp fixing, etc.).

[0034] According to an embodiment, the outer surface is a moulding surface configured to mould the shear web and / or a connection area between the shear web and a spar cap of the blade.

[0035] According to other embodiments, the first and second mandrels include mating outer surfaces defining a gap for accommodating the fiber layup for molding the shear web. Furthermore, at least one of the one or more sensors is arranged at one of the mating surfaces.

[0036] According to other embodiments, at least one of the one or more sensors is arranged in a middle portion of the first and second mandrels with respect to a vertical direction of the mold, the vertical direction of the mold pointing from the lower mold to the upper mold.

[0037] Therefore, it is possible to monitor the resin infusion and / or curing process in the interior and / or innermost area of ​​the mold. In particular, the middle portion is relatively far away from the lower and upper molds. Monitoring the resin infusion and / or curing process in the middle portion has special advantages because the resin (which is usually provided by an inlet close to the lower and / or upper mold) must pass through a relatively long path to reach this area. In addition, during the resin flow and curing, the lower and upper molds are usually heated to control the temperature. However, it is difficult to transfer heat from the lower and upper molds to the middle portion that is arranged away from the lower and upper molds. Therefore, it is particularly important to monitor the temperature and resin flow in the middle portion.

[0038] The vertical direction of the mould is, for example, the vertical direction of a manufacturing site / workshop for manufacturing the blades.

[0039] The dimension of the middle portion in the vertical direction is, for example, less than one third of the maximum height of the first and second mandrel and / or less than 10% of the maximum height of the first and second mandrel.

[0040] According to other embodiments, the first and second mandrels comprise several of the sensors, and

[0041] The plurality of sensors are arranged to be spaced apart from each other in a vertical direction of the mold, the vertical direction of the mold being directed from the lower mold to the upper mold, and / or

[0042] The plurality of sensors are arranged to be spaced apart from each other in a longitudinal direction of the mold.

[0043] Thus, monitoring of the resin flow and curing is improved. For example, it is possible to monitor the resin flow and curing over a considerable range of the height and / or length of the blade.

[0044] The several sensors are, for example, arranged spaced apart from one another in the vertical direction such that they are distributed over the entire maximum height of the first and / or second spindle.

[0045] The several sensors are for example arranged spaced apart from one another in the longitudinal direction such that they are distributed over the entire length of the fiber layup which is configured to form a shear web or a longitudinal portion of a shear web in the cured state.

[0046] The longitudinal direction is in particular arranged parallel to a direction from an inboard section to an outboard section of the mould, i.e. from a root section to a tip section of the mould. The inboard section, the outboard section, the root section and the tip section of the mould are in particular sections of the mould configured for moulding the inboard part, the outboard part, the root part and the tip part of the blade, respectively.

[0047] According to other embodiments, the method comprises the steps of creating one or more recesses in the outer surface of the first and / or second mandrel and arranging each of the one or more sensors in one of the recesses.

[0048] Having (one or more) recesses allows for better placement of (one or more) sensors. For example, one or more sensors may be placed in (one or more) recesses so that they do not protrude from the outer surface of the first and / or second mandrel, and / or so that they are flush with the outer surface.

[0049] Creating the one or more recesses includes, for example, cutting, machining and / or embossing the one or more recesses in the outer surface.

[0050] The first and / or second mandrel each comprises a foam portion, for example having the outer surface.The one or more recesses are created, for example, by cutting and / or embossing the foam portion.

[0051] The one or more sensors are each fixed in one of the recesses, for example (eg by using an adhesive or by mechanical fixing).

[0052] The size of the one or more recesses is, for example, about several centimeters. The width and / or length of the one or more recesses is, for example, 5 cm or less, 3 cm or less, 2 cm or less, and / or 1 cm or less. In addition, the depth of the one or more recesses is, for example, 2 cm or less, 1 cm or less, 0.5 cm or less.

[0053] According to other embodiments, the method comprises the step of covering each of the first and second mandrels comprising the one or more sensors with a vacuum bag.

[0054] Thus, the one or more sensors are arranged below the vacuum bag. In other words, the vacuum bag separates the one or more sensors from the space in which the vacuum is created and the resin is poured into. Thus, the one or more sensors are not in contact with the resin. This allows better protection of the one or more sensors. Furthermore, the one or more sensors can be reusable.

[0055] The first and second mandrels including the one or more sensors may also be covered with more than one vacuum bag, thereby increasing the sealing of the enclosed space and improving the creation of the vacuum.

[0056] According to other embodiments, in step d), the temperature at the location of the one or more sensors, the arrival of the resin at the location of the one or more sensors and / or the curing state of the resin are monitored.

[0057] Monitoring the temperature of the first and / or second mandrels, the fiber layup between the mandrels, and / or the resin flowing in the gap between the mandrels allows, for example, monitoring and / or controlling the temperature of the resin so that the temperature-dependent viscosity of the resin is suitable for the desired resin flow. The temperature of the resin can be controlled by increasing the heating of the mold.

[0058] Monitoring the arrival of resin at the location of one or more sensors allows monitoring and / or controlling the current location of the resin and the flow front of the resin during infusion. The resin flow may be controlled by controlling the supply of resin through the mold inlet.

[0059] Where the first and / or second mandrel comprises more than one sensor spaced apart from one another, the position of the resin may be monitored as it flows through the fiber layup and along several sensors.

[0060] The one or more sensors are in particular configured to acquire sensor data, the sensor data comprising temperature, electrical properties and / or dielectric properties.

[0061] Monitoring the electrical and / or dielectric properties of the resin, which are dependent on the structural properties of the resin, allows for control of the cure state of the resin.

[0062] In an embodiment, the one or more sensors may also be configured to acquire sensor data, which includes position data and / or time data in addition to the physical measurement data. The position data may indicate the position at which the measured quantity was measured. The time data may indicate the time at which the measurement data was acquired. For example, the sensor data of a temperature sensor placed in a specific position may include the temperature measured at this position and also include the spatial coordinates of this position and the measurement time.

[0063] Having position data allows to display the measurement data as a function of the position data. Thus, this allows to display, for example, the spatial distribution of the measurement data, such as the temperature distribution.

[0064] Having time data allows to display the measurement data as a function of the time data. This therefore allows to display the time evolution of the measurement data. For example, the development of the flow front of a resin can be displayed.

[0065] According to other embodiments, the one or more sensors include a temperature sensor and / or a capacitive sensor.

[0066] Having a temperature sensor allows monitoring whether the temperature-dependent viscosity of the resin is suitable for the desired resin flow and for uniform wetting of the fiber layup with the resin. Furthermore, the temperature sensor allows monitoring of the temperature-dependent curing process.

[0067] Having capacitive sensors allows monitoring the arrival of resin at the respective sensors and the curing state of the resin.

[0068] According to other embodiments, the one or more sensors are wireless sensors.

[0069] The one or more sensors particularly comprise an antenna for transmitting and receiving data, for example for transmitting acquired sensor data to a remote control unit.

[0070] The one or more sensors may also comprise a battery unit and thus be, for example, an active radio frequency sensor (in contrast to a passive radio frequency sensor which receives energy / power via a radio frequency signal).

[0071] According to other embodiments, the one or more sensors have a connection range of up to 0.1 km or more, up to 0.3 km or more, up to 0.5 km or more, up to 0.7 km or more and / or up to 1 km or more, and / or

[0072] The transmission frequency of the one or more sensors is in the range of 100 MHz to 1 GHz, 300 MHz to 1 GHz, 400 MHz to 950 MHz, 800 MHz to 950 MHz and / or 868 MHz to 915 MHz.

[0073] In the case of the connection range, the one or more sensors are long range RF sensors. Thus, RF signals can be transmitted from the location of the sensor (adjacent to the fiber layup forming the shear web in the infused and cured state) to the outside of the mold.

[0074] With said transmission frequency range, the radio frequency signal can better transmit the structure of the blade and the mold during manufacturing, for example the carbon structure. For example, during manufacturing, the radio frequency signal can better transmit the carbon beams arranged at the top and the bottom of the blade. For example, the radio frequency signal can better transmit the first and / or second mandrels even if they include carbon layers.

[0075] According to other embodiments, the one or more sensors each include a switch unit for switching between an activated state in which the corresponding sensor acquires sensor data and an inactivated state in which the corresponding sensor does not acquire sensor data.

[0076] Thus, when the resin infusion and curing process is completed and / or during an interruption of the resin infusion and curing process, the one or more sensors can be turned off. This allows energy (e.g., battery energy) to be saved. By saving battery energy, the frequency of replacement of battery cells can be reduced.

[0077] According to other aspects, a mould arrangement for manufacturing a wind turbine blade is provided. The mould arrangement comprises:

[0078] Lower mold,

[0079] an upper mold configured to be arranged on the lower mold so that an internal cavity is formed in a closed state of the molds, and

[0080] first and second mandrels, the first and second mandrels being configured to be arranged in the inner cavity so that a gap is formed between the first and second mandrels, the gap extending in a vertical direction of the mold, the vertical direction of the mold pointing from the lower mold to the upper mold in the closed state, and the gap being configured to accommodate a fiber layup for molding a shear web of the blade, wherein

[0081] The first and / or second mandrel comprises one or more sensors arranged at an outer surface thereof and adjacent to the gap.

[0082] The embodiments and features described with reference to the method of the invention apply mutatis mutandis to the mould arrangement of the invention.

[0083] Other possible implementations or alternative solutions of the present invention also cover combinations of features related to the embodiments described above or below (which are not explicitly mentioned in this article). Those skilled in the art can also add separate or independent aspects and features to the most basic form of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Other embodiments, features and advantages of the present invention will become apparent from the subsequent description and the dependent claims in conjunction with the accompanying drawings, in which:

[0085] Figure 1 A wind turbine according to an embodiment is shown;

[0086] Figure 2 A cross-sectional view of a mold arrangement according to an embodiment is shown, wherein the mold arrangement is used to manufacture Figure 1 wind turbine blades for wind turbines;

[0087] Figure 3 It is shown that according to the embodiment, Figure 2 A cross-sectional view of a wind turbine blade manufactured using the mold arrangement shown in FIG.

[0088] Figure 4 It shows that according to the embodiment Figure 2 Schematic diagram of the sensor of the mandrel of the mold arrangement structure shown in;

[0089] Figure 5 Shown in cross section Figure 2 Other embodiments of the mandrel of the mold arrangement structure;

[0090] Figure 6 A partial perspective view is shown Figure 2 Other embodiments of the mandrel of the mold arrangement structure; and

[0091] Figure 7 A flow chart according to an embodiment is shown, which illustrates the use of Figure 2 Mold to manufacture Figure 1 A method for a wind turbine blade of a wind turbine.

[0092] In the drawings, like reference numbers indicate identical or functionally equivalent elements, unless otherwise indicated. DETAILED DESCRIPTION

[0093] Figure 1A wind turbine 1 according to an embodiment is shown. The wind turbine 1 comprises a rotor 2 having one or more blades 3, which are connected to a hub 4. The hub 4 is connected to a generator (not shown) arranged in a nacelle 5. During operation of the wind turbine 1, the blades 3 are driven in rotation 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 is erected 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.

[0094] The following will be relative to Figures 2 to 7 An improved method for manufacturing a wind turbine blade 3 according to an embodiment will be described.

[0095] Figure 2 The cross section shows the Figure 1 A mold arrangement 8 is provided for one of the wind turbine blades 3. The mold arrangement 8 comprises a lower mold 9 and an upper mold 10. Figure 2 In the closed state of the mold arrangement 8 shown in FIG. 1 , the upper mold 10 is arranged on the lower mold 9 so that an internal cavity 11 is formed. The mold arrangement 8 also includes a first mandrel 12 and a second mandrel 13. The mandrels 12, 13 are arranged in the cavity 11 formed by the lower and upper molds 9, 10. The mandrels 12, 13 are therefore mold cores.

[0096] In the closed state of the mould arrangement 8, gaps 14, 15, 16 are formed between the lower and upper moulds 9, 10 and the first and second mandrels 12, 13 for moulding the blade 3. In particular, a first gap 14 is formed between the lower mould 9 and the first and second mandrels 12, 13 for moulding a lower shell 17 ( Figure 3 In addition, a second gap 15 is formed between the upper mold 10 and the first and second mandrels 12 and 13 for molding the upper shell 18 of the blade 3 ( Figure 3 ).

[0097] In addition, the third gap 16 ( Figure 2 ) is formed between the first and second mandrels 12, 13 for molding the shear web 19 of the blade 3 ( Figure 3 ). The third gap 16 is defined by the mating outer surfaces 20a and 20b of the first and second mandrels 12, 13, respectively. The third gap 16 extends in 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 8). The vertical direction V particularly points from the lower mold 9 to the upper mold 10 during the molding process.

[0098] The first and second gaps 14, 15 ( Figure 2 ) is configured to accommodate the lower and upper shells 17, 18 for molding ( Figure 3 ) of the fiber layer 21. In addition, the third gap 16 is configured to accommodate the shear web 19 ( Figure 3 )'s fiber layer 22. Figure 2 Also shown are two precast beams 23 arranged in the lower and upper molds 9, 10, respectively. The two precast beams 23 are configured to become spar caps 24 ( Figure 3 ).

[0099] like Figure 2 As shown in FIG. 1 , the fiber layups 21 , 22 are infused with resin 25 and the resin 25 is cured to form the fiber reinforced resin laminate (i.e., the shells 12 , 18 , the shear webs 19 and the connections between the shear webs 19 , the spar caps 24 and the shells 17 , 18 )

[0100] In order to monitor the infusion and curing process of the resin 25, the first and second mandrels 12, 13 include one or more sensors 26, which are arranged at the outer surfaces 20a-20d and adjacent to the third gap 16, such as Figure 2 As shown in the enlarged section of Figure 2 In the example of , one sensor 26 is shown to be arranged at the outer surface 20a of the first mandrel 12. The sensor 26 can be accommodated in a recess 27 of the outer surface 20a of the first mandrel 12, as illustrated. The sensor 26 can be fixed at the surface 20a and / or in the recess 27, for example, by an adhesive. In addition, the sensor 26 is arranged in a middle portion 28 of the first and second mandrels 12, 13. The middle portion 28 is the middle portion relative to the vertical direction V of the mold 9, 10.

[0101] In other examples, more than one sensor 26 may also be arranged at the outer surfaces 20a-20d and adjacent to the third gap 16. Furthermore, instead of or in addition to being arranged at the outer surfaces 20a, 20c of the first spindle 12, one or more sensors 26 may also be arranged at the outer surfaces 20b, 20d of the second spindle 13. Furthermore, instead of or in addition to being arranged in the middle portion 28, one or more of the sensors 26 may also be arranged outside the middle portion 28. It is also possible that one or more sensors 26 are arranged at flat (i.e., without recesses) outer surfaces 20a-20d, rather than being arranged in recesses 27 of the outer surfaces 20a-20d. In addition, one or more sensors 26 may also be fixed to the first and / or second spindles 12, 13 by other means than adhesive.

[0102] One or more sensors 26 are, for example, wireless sensors that include a radio frequency (RF) transmitter / receiver 29 (eg, antenna 29, Figure 4One or more sensors 26 may transmit acquired sensor data to a remote computing device 31 using antenna 29 via wireless communication ( Figure 2 ), the remote computing device 31 has another RF transmitter / receiver 32 (eg, another antenna 32). One or more sensors 26 may be remotely controlled using antenna 29 via wireless communication (eg, via RF signals 30' from computing device 31).

[0103] The one or more sensors 26 are, for example, long-range radio frequency sensors having a connection distance of up to 0.5 km to 1 km. Furthermore, the transmission frequency of the one or more sensors 26 is, for example, in the range of 100 MHz to 1 GHz.

[0104] The one or more sensors 26 include, for example, a housing 33 ( Figure 4 ) and a measuring unit 34 at least partially accommodated in the housing 33. The measuring unit 34 may include one or more printed circuit boards having one or more integrated circuits, etc., for measuring sensor data and controlling the sensor 26. The one or more sensors 26 may also have a battery unit 35 for power supply. The one or more sensors 26 include, for example, a switch unit 36 ​​for switching between an activation state in which the corresponding sensor 26 acquires sensor data and an inactivation state in which the corresponding sensor 26 does not acquire sensor data.

[0105] As in Figure 5 As exemplarily shown for the first mandrel 12' in FIG, each of the first and second mandrels 12, 13 may include a core 37 and a foam portion 38 covering the core 37. The core 37 includes, for example, a support structure 39 made of wood and surrounding a cavity 40. The core 37 may also include a carbon layer 41 covering the support structure 39. Then, one or more sensors 26' are arranged, for example, at the outer surface 20a' of the foam portion 38 or in a recess 27' of the outer surface 20a' of the foam portion 38.

[0106] Figure 6 For the first spindle 12 ″, the case where the first and / or second spindle 12, 13 comprises more than one sensor 26 ″ is exemplarily illustrated, wherein the more than one sensor 26 ″ is arranged along the vertical direction V and along the longitudinal direction L of the spindle 12 ″ (which is also the longitudinal direction L of the mold 9, 10 and the mold arrangement 8, Figure 2 ) are separated. Figure 6 As an example, three sensors 26" are shown spaced apart in the vertical direction V at the first longitudinal position L1. In addition, at each of the second and third longitudinal positions L2, L3, there are three sensors 26" spaced apart in the vertical direction V (at Figure 6In each position L2, L3, only two of the three sensors 26" can be seen. Therefore, Figure 6 The sensor 26" in is also arranged along the longitudinal direction L.

[0107] Figure 7 Shows the use of Figure 2 Flow chart of a method for manufacturing a wind turbine blade 3 using the described mold arrangement 8. Note that, Figure 5 and 6 The embodiments of the mandrels 12 , 12 ′, 12 ″, 13 and sensors 26 , 26 ′, 26 ″ shown in FIG. 1 can also be used for the manufacturing method.

[0108] In the first step S1 of the method, the lower mold 9 ( Figure 2 ) is provided. For forming the lower shell 17 ( Figure 3 ) of the fiber layup 21 and the vacuum bag (not shown) are arranged in the lower mold 9. In addition, the precast beam 23 is arranged in the lower mold 9.

[0109] In a second step S2 of the method, one or more sensors 26 are arranged and fixed at the outer surface 20a-20d of the first and / or second mandrel 12, 13. This may include creating (e.g. cutting) one or more recesses 27 in the outer surface 20a-20d and arranging the one or more sensors 26 in the one or more recesses 27.

[0110] In a third step S3 of the method, the first and second mandrels 12, 13, each including one or more sensors 26, are vacuum bagged 42 ( Figure 2 )cover.

[0111] In the third step S3 of the method, the fiber layup 22 for shearing the web 19 and the first and second mandrels 12, 13 are arranged in the lower mold 9. The first and second mandrels 12, 13 are particularly arranged in the lower mold 9 so that a gap 16 (third gap 16) is formed between the first and second mandrels 12, 13. The gap 16 is defined by the mating outer surfaces 20a, 20b of the first and second mandrels 12, 13. In addition, the fiber layup 22 for shearing the web 19 is arranged in the gap 16. Since the first and / or second mandrels 12, 13 include one or more sensors 26 at their respective outer surfaces 20a-20d, by arranging the mandrels 12, 13, the one or more sensors 26 are arranged adjacent to the gap 16 and adjacent to the fiber layup 22 for shearing the web 19.

[0112] In the fourth step S4 of the method, the upper mold 10 is arranged on top of the lower mold 9 and the first and second mandrels 12 and 13, and the upper mold 10 includes a mold for molding the upper shell 18 ( Figure 3) and a precast beam 23 for forming an upper wing spar cap 24.

[0113] In a fifth step S5 of the method, vacuum is applied to the space 43 between the upper and lower moulds 9, 10 and the mandrels 12, 13. The space 43 is defined in particular by the first, second and third gaps 14, 15, 16.

[0114] In a sixth step S6 of the method, resin 25 is provided through an inlet (not shown) and is sucked by the generated vacuum into the space 43, ie through the gaps 14, 15, 16. In this way, the fiber lay-ups 21, 22 are infused with resin 25.

[0115] In a seventh step S7 of the method, the resin is cured, for example by heating.

[0116] In an eighth step S8 of the method, the infusion and / or curing of the resin 25 is monitored by means of one or more sensors 26. In particular, sensor data are acquired by the one or more sensors.

[0117] Step S8 may be performed before steps S6 and S7, simultaneously with steps S6 and / or S7, and / or after steps S6 and S7. For example, sensor data, such as the temperature of the surface 20a-20d of the mandrel 12, 13, the gap 16, and / or the fiber layup 22 in the gap 16, may be acquired before opening one or more resin inlet channels (not shown) to start infusion (step S6). This allows the resin infusion (step S6) to be started only when the corresponding temperatures have suitable values. In another example, sensor data of the surface 20a-20d of the mandrel 12, 13, the gap 16, the fiber layup 22 in the gap 16, and / or the resin 25 flowing through the gap 16 may be acquired during infusion (step S6) and / or curing (step S7) of the resin 25 (step S8).

[0118] In step S8, the acquired sensor data may be processed by a computing device 31 ( Figure 2 ) to process. The sensor 26 is, for example, wirelessly connected to the computing device 31. The sensor data is interpreted and interpolated, for example using a data analysis model, to prepare for visualization. The data can, for example, be processed to derive the temperature of the mandrels 12, 13 or the spatial distribution of the flow front of the resin 25.

[0119] In step S8, the sensor data and / or processed sensor data may be displayed, for example, on a display unit 44 of the computing device 31. Thus, information about the infusion and curing process in the closed mold 9, 10 may be made available to the operator by means of the display unit 44. If the operator finds that, for example, the flow front of the resin 25 does not develop as desired, he / she may take measures in step S6 to change the infusion process.

[0120] Thus, casting of the shear web 19 may be improved using one or more sensors 26 disposed adjacent to a fiber layup 22 configured to become the shear web 19 in the cured state of the resin 25 .

[0121] Although the invention has been described in terms of preferred embodiments, modifications will be apparent to those skilled in the art.

Claims

1. A method for manufacturing a wind turbine blade (3), comprising the following steps: a) arranging (S3, S4) first and second mandrels (12, 13) and an upper mould (10) on a lower mould (9), wherein a fibre lay-up (21, 22) is arranged in the lower mould (9), in the upper mould (10) and between the first and second mandrels (12, 13) for moulding a lower shell (17), an upper shell (18) and a shear web (19) of the blade (3), respectively, and wherein the first and / or second mandrel (12, 13) comprises one or more sensors (26) arranged at an outer surface (20a-20d) thereof and adjacent to the fibre lay-up (22) arranged for moulding the shear web (19), b) applying (S5) a vacuum to the space (43) between the upper and lower moulds (9, 10) and the mandrels (12, 13), c) infusing (S6) the fiber lay-ups (21, 22) with resin (25) and curing (S7) the resin (25), and d) monitoring ( S8 ) the infusion and / or curing of the resin ( 25 ) by means of the one or more sensors ( 26 ).

2. The method according to claim 1, wherein: The outer surface (20a-20d) is a molding surface configured to mold the shear web (19) and / or the connection area (R) between the shear web (19) and the spar cap (24) of the blade (3).

3. The method according to claim 1 or 2, wherein: The first and second mandrels (12, 13) include mating outer surfaces (20a, 20b), which define a gap (16) for accommodating a fiber layup (22) for molding the shear web (19), and wherein at least one of the one or more sensors (26) is arranged at one of the mating surfaces (20a, 20b).

4. The method according to claim 1, wherein: At least one of the one or more sensors (26) is arranged in a middle part (28) of the first and second spindles (12, 13) relative to a vertical direction (V) of the molds (9, 10), and the vertical direction (V) of the molds (9, 10) points from the lower mold (9) to the upper mold (10).

5. The method according to claim 1, wherein: The first and second mandrels (12, 13) include a number (26, 26', 26") of the sensors, and The plurality of sensors (26, 26', 26") are arranged to be spaced apart from each other in a vertical direction (V) of the molds (9, 10), the vertical direction (V) of the molds (9, 10) pointing from the lower mold (9) to the upper mold (10), and / or The plurality of sensors (26, 26', 26") are arranged to be spaced apart from each other in the longitudinal direction (L) of the mold (9, 10).

6. The method according to one of claims 1 to 5, comprising the following steps: One or more recesses (27) are created in the outer surfaces (20a-20d) of the first and second mandrels (12, 13), and each of the one or more sensors (26) is disposed in one of the recesses (27).

7. The method according to one of claims 1 to 6, comprising the following steps: Each of the first and second mandrels (12, 13) including the one or more sensors (26) is covered with a vacuum bag (42).

8. The method according to claim 1, wherein: In step d), the temperature at the location of the one or more sensors (26), the arrival of the resin (25) at the location of the one or more sensors (26) and / or the curing state of the resin (25) are monitored.

9. The method according to claim 1, wherein: The one or more sensors (26) include a temperature sensor and / or a capacitive sensor.

10. The method according to claim 1, wherein: The one or more sensors (26) are wireless sensors.

11. The method according to claim 10, wherein The one or more sensors (26) have a connection range of up to 0.1 km or more, up to 0.3 km or more, up to 0.5 km or more, up to 0.7 km or more and / or up to 1 km or more, and / or The transmission frequency of the one or more sensors (26) is in the range of 100 MHz to 1 GHz, 300 MHz to 1 GHz, 400 MHz to 950 MHz, 800 MHz to 950 MHz and / or 868 MHz to 915 MHz.

12. The method according to claim 1, wherein: The one or more sensors (26) each include a switch unit (36) for switching between an activated state in which the corresponding sensor (26) acquires sensor data and an inactivated state in which the corresponding sensor (26) does not acquire sensor data.

13. A mould arrangement (8) for manufacturing a wind turbine blade (3), comprising: Lower mold (9), an upper mold (10) configured to be arranged on the lower mold (9) so that an inner cavity (11) is formed in a closed state of the molds (9, 10), and a first and a second mandrel (12, 13), the first and the second mandrel (12, 13) being configured to be arranged in the inner cavity (11) such that a gap (16) is formed between the first and the second mandrel (12, 13), the gap (16) extending in a vertical direction (V) of the mould (9, 10), the vertical direction (V) of the mould (9, 10) pointing from the lower mould (9) to the upper mould (10) in the closed state, and the gap (16) being configured to accommodate a fibre layup (22) for moulding a shear web (19) of the blade (3), wherein The first and second mandrels (12, 13) include one or more sensors (26) disposed at an outer surface (20a-20d) thereof and adjacent to the gap (16).

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