Method for manufacturing wind turbine blades and mold for manufacturing wind turbine blades

Abstract

A method for manufacturing wind turbine blades (3) includes the following steps: - arranging an upper mold (10, 10') (S2, S2') on a lower mold (9, 9'), wherein a dry fiber layup (11, 11') is arranged in the upper mold (10, 10') or in the upper mold (10, 10') and the lower mold (9, 9'), - extending the space (15, 1...) between the upper and lower molds (10, 10', 9, 9') into the space (15, 1...) 5') Apply (S3, S3') a vacuum, and - infuse (S5, S8) the dry fiber layup (11, 11') in the upper and / or lower molds (10, 10', 9, 9') with resin (17), wherein the resin (17) is supplied (S4, S7') at least partially through at least one upper resin inlet (16, 16', 37, 38) located at the upper portion (29, 29') of the upper mold (10, 10'). Having at least one upper resin inlet on the upper mold allows for improved vacuum-assisted resin infusion. For example, the resin supplied through at least one upper resin inlet must be raised to a small height to reach the top of the mold. For example, the resin flow supplied through at least one upper resin inlet is supported by gravity in a downward direction.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing wind turbine blades and a mold for manufacturing wind turbine blades. Background Technology

[0002] One way to generate more power from wind turbines under given wind conditions is to increase the size of the blades. However, manufacturing wind turbine blades has become increasingly difficult when it comes to increasing blade size.

[0003] Currently, many wind turbine blades are manufactured by prefabricating blade components, such as pressure-side and suction-side housings, separately and then gluing these components together. For example, components are prefabricated by infusing a composite material (such as fiberglass) with resin and then curing the resin. However, the gluing process has many drawbacks. For instance, it is difficult to achieve sufficient strength and stability in the glued lines.

[0004] In another method disclosed in EP1310351A1, the blade is manufactured by wrapping the entire blade or longitudinal blade section of composite material around a mandrel (mold core) and then infusing and curing the resin in a vacuum-assisted manner. This avoids glued joints.

[0005] However, as blade size increases, and consequently, blade cross-section increases, it becomes difficult to elevate the resin to the top of the blade using vacuum-assisted infusion. The combined gravity and density of the resin used for infusion limit the maximum height the resin can be raised using only a vacuum. Therefore, manufacturing large wind turbine blades, for example, with a diameter greater than approximately 5.5 meters at the root section, using vacuum-assisted infusion is challenging. Summary of the Invention

[0006] One object of the present invention is to provide an improved method for manufacturing wind turbine blades.

[0007] Therefore, a method for manufacturing wind turbine blades is provided. The method includes the following steps:

[0008] - The upper mold is placed on the lower mold, wherein the dry fiber layup is arranged in the upper mold or in both the upper and lower molds.

[0009] - Apply a vacuum to the space between the upper and lower molds, and

[0010] - The dry fiber layup in the upper and / or lower mold is infused with resin, wherein the resin is provided at least partially through at least one upper resin inlet channel disposed at the upper part of the upper mold.

[0011] Having at least one upper resin inlet channel in the upper mold allows for improved vacuum-assisted resin infusion. For example, resin supplied through at least one upper resin inlet channel must be raised to a smaller height to reach the top of the mold. Furthermore, higher resin inlet pressures are permissible during the initial stages of the infusion process. For example, the resin flow supplied through at least one upper resin inlet channel is supported downwards by gravity. Therefore, even for large blade cross-sections, dry fiber layups in the upper and lower molds can be better wetted with resin. Consequently, areas of dryness can be better prevented in the manufactured blade. Additionally, the time required to infuse the entire blade can be reduced.

[0012] Wind turbine blades are 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 includes, for example, a rotor, a nacelle, and a tower. The rotor has one or more blades, each connected to a hub. The nacelle contains a generator, and the tower holds the nacelle at its top. The tower of a wind turbine can be connected to the base of the wind turbine, such as a monopile in the seabed, via a transition piece.

[0013] Wind turbine blades (e.g., their root section) are fixedly or rotatably connected to a hub. Except for the (cylindrical) root section, the wind turbine blades are aerodynamically shaped. A wind turbine blade includes, for example, a pressure side (upwind side) and a suction side (downwind side). The pressure side and suction side are connected to each other at the leading and trailing edges. The pressure side and suction side, as well as the leading and trailing edges, define the airfoil of the wind turbine blade.

[0014] Specifically, wind turbine blades are manufactured by arranging dry fiber layups in a lower mold and an upper mold, injecting resin into the dry fiber layups through a vacuum-assisted resin infusion process, and then curing the resin.

[0015] Wind turbine blades can be manufactured as single pieces. In this case, dry fiber layups for the entire blade are arranged in a lower mold and an upper mold, and then resin is poured in and cured.

[0016] Alternatively, wind turbine blades can be manufactured by prefabricating longitudinal blade segments (e.g., inner and outer blade segments) and joining them together to form a complete blade. In this case, the dry fiber layup for the first longitudinal blade segment is arranged in a lower mold and an upper mold, and then infused with resin and cured. Then, the dry fiber layup for the remaining longitudinal blade segments is arranged in a lower mold (or another lower mold) and an upper mold (or another upper mold), and infused with resin and cured. After prefabricating two or more longitudinal blade segments, the segments are joined together by any suitable method to form a complete blade.

[0017] For example, the fibers are arranged in lower and upper molds under dry conditions (i.e., as fibers without resin). The fibers may also be (partially) pre-impregnated fibers (prepreg materials). Fibers include, for example, glass fibers, carbon fibers, aramid fibers, and / or natural fibers.

[0018] The fiber layup may include a core material, such as wood, balsa wood, PET foam, and / or PVC foam. The core material may be sandwiched between the fiber layers to obtain a fiber-reinforced resin laminate with a core structure.

[0019] Furthermore, the reinforcing beams can be arranged in the mold and can be attached to the fiber layup via a resin infusion and curing process. The reinforcing beams may include leading-edge beams, trailing-edge beams, suction-side beams, and / or pressure-side beams.

[0020] Furthermore, one or more webs can be arranged in a mold and attached to the fiber layup via a resin infusion and curing process. One or more webs include, for example, shear webs that connect the pressure-side and suction-side blade shells within the cavity of the manufactured blade. The shear webs provide shear strength to the blade.

[0021] Precast elements can also be arranged together with dry fibers. For example, reinforcing beams and / or webs can be precast elements.

[0022] A mold for manufacturing a wind turbine blade or a longitudinal section of a wind turbine blade includes a lower mold and an upper mold. A fiber layup for forming the lower shell (e.g., the suction side of the blade) or a longitudinal section of the lower shell may be arranged in the lower mold, and a fiber layup for forming the upper shell (e.g., the pressure side of the blade) or a longitudinal section of the upper shell may be arranged in the upper mold.

[0023] The upper mold is arranged on the lower mold, thereby forming a cavity between them. The mold may also include a mold core in the mold cavity.

[0024] The dry fibers can be placed in the upper mold before the upper mold is placed on the lower mold. In this case, placing the upper mold on the lower mold means placing the upper mold with the dry fiber layup on the lower mold.

[0025] Alternatively, the dry fiber layup (e.g., for forming the upper blade shell) may be placed on top of the mold core disposed in the lower mold before the upper mold is placed on the lower mold. In this case, placing the upper mold on the lower mold means placing the upper mold without the dry fiber layup on the mold core with the dry fiber layup. At the end of placing the upper mold on the lower mold, the dry fiber layup is placed in the upper mold core.

[0026] The fiber layup in the lower and upper molds can be covered by a vacuum bag, and a vacuum can be created in the space covered by the vacuum bag (e.g., in the space between the lower and upper molds and the vacuum bag). Resin is then supplied through at least one upper resin inlet channel, and due to the created vacuum, the resin is infused into the space, thereby wetting the fibers.

[0027] Resins include, for example, thermosetting plastics, thermoplastic plastics, epoxy resins, polyurethanes, vinyl esters and / or polyesters.

[0028] For example, the resin is cured by applying heat. The result is a fiber-reinforced resin laminate.

[0029] Specifically, at least one upper resin inlet channel is at least one elongated fluid supply line having one or more openings through which resin is infused into the fiber layup. At least one upper resin inlet channel is, for example, at least one upper resin inlet channel. At least one upper resin inlet channel includes an opening at its top along its length through which resin is infused into the fiber layup. Such a channel(s) may be rigid or flexible. Specifically, at least one upper resin inlet channel is arranged along the longitudinal direction of the upper die. The longitudinal direction of the upper die defines the longitudinal direction of the manufactured blade.

[0030] At least one upper resin inlet channel includes, for example, two or more upper resin inlet channels. The two or more upper resin inlet channels may be arranged, for example, parallel to each other. At least one upper resin inlet channel includes, for example, two, four, or other even numbers of upper resin inlet channels. The two, four, or other even numbers of upper resin inlet channels are arranged symmetrically, for example, with respect to a vertical plane intersecting the longitudinal axis of the mold / blade.

[0031] The at least one upper resin inlet channel being arranged in the upper part of the upper mold specifically means that at least one upper resin inlet channel is arranged in a volume defined by the upper part of the upper mold.

[0032] At least one upper resin inlet channel is arranged at the upper part of the upper mold, including the case where at least one upper resin inlet channel is arranged directly at the upper mold, and the case where another element, such as a dry fiber layup, is arranged between at least one upper resin inlet channel and the upper mold.

[0033] At least one upper resin inlet channel is arranged, for example, between the upper mold and the dry fiber layup in the upper mold. Alternatively, at least one upper resin inlet channel is arranged on the inside of the dry fiber layup in the upper mold, wherein the inside faces away from the upper mold.

[0034] Specifically, the upper part of the upper mold includes the top or the middle of the upper mold. Therefore, at least one upper resin inlet channel is arranged, for example, at the top of the upper mold. In another example, at least one upper resin inlet channel is arranged at an intermediate position between the top and bottom of the upper mold. At least one upper resin inlet channel is arranged, for example, at an intermediate position between the upper end and the lower end of the upper mold.

[0035] According to an embodiment, at least one additional resin inlet channel is arranged at the upper or lower mold and at a different height than the at least one upper resin inlet channel. Furthermore, in addition to the resin supplied through the at least one upper resin inlet channel, the dry fiber lay-ups in the upper and lower molds are infused with resin supplied through the at least one additional resin inlet channel.

[0036] Arranging at least one additional resin inlet channel at a different height than at least one upper resin inlet channel allows resin to be supplied at two different heights. Therefore, the upward flow of resin through the fiber layup and / or the downward flow of resin can be supported respectively by resin inlet channels arranged at a larger / smaller height.

[0037] Specifically, at least one additional resin inlet channel is arranged at a different height relative to the bottom or lower end of the lower mold than at least one upper resin inlet channel. Specifically, at least one additional resin inlet channel is arranged horizontally relative to the floor of the manufacturing site at a different height than at least one upper resin inlet channel.

[0038] At least one upper resin inlet channel is arranged at a greater height than at least one other resin inlet channel.

[0039] At least one additional resin inlet channel is arranged, for example, in the connection area between the upper and lower molds.

[0040] At least one additional resin inlet channel is arranged at the upper or lower mold, including cases where at least one additional resin inlet channel is arranged directly at the upper / lower mold and cases where another element, such as a dry fiber layup, is arranged between at least one additional resin inlet channel and the upper / lower mold.

[0041] Specifically, at least one additional resin inlet channel is at least one additional elongated fluid supply line with an opening through which resin is infused into the fiber layup. The at least one additional resin inlet channel is, for example, at least one additional resin inlet channel having an opening along its length through which resin is supplied. Such an additional channel(s) may be rigid or flexible. Specifically, at least one additional resin inlet channel is arranged along the longitudinal direction of the upper mold / manufactured blade.

[0042] According to another embodiment, the method includes the step of detecting the position of the resin during resin flow through dry fiber layups in upper and lower molds.

[0043] Detecting the location of the resin (e.g., the flow front of the resin) during resin flow through the dry fiber layup allows for better control of the infusion process. For example, it allows for better control over how resin is delivered through a specific resin inlet channel, such as the amount of resin, the resin inlet pressure, and / or the timing.

[0044] The position of the resin is detected by one or more sensors. These sensors may be arranged, for example, within the internal structure of the upper and / or lower mold, such as within one or more drilled holes in the upper and / or lower mold. Alternatively or additionally, the sensors may also be arranged on the inner surface of the mold. The sensors may be wired or wirelessly connected to a computing unit. The sensors may be, for example, RFID sensors (Radio Frequency Identification sensors).

[0045] One or more sensors may be, for example, gossip suction ports placed in the mold. A gossip suction port comprises a small suction port having a transparent tube arranged in one or more through-holes in the mold. Resin becoming visible within the transparent tube indicates that resin has reached the gossip suction port.

[0046] One or more sensors may be, for example, pressure sensors, thermal sensors, and / or dielectric sensors in or at the mold. One or more sensors may include, for example, inspection glass in the mold and / or a semi-transparent mold.

[0047] One or more sensors may also include, for example, a pipeline sensor that detects the position of the resin along the pipeline. The pipeline sensor may be, for example, an optical pipeline sensor and / or a dielectric pipeline sensor.

[0048] According to another embodiment, the position of the resin is detected at at least one upper resin inlet channel, at at least one additional resin inlet channel, and / or at the lower part or bottom of the lower mold.

[0049] Therefore, the arrival and / or passage of resin flowing through the dry fiber layup in the upper and lower molds can be detected at at least one upper / additional resin inlet channel and / or at the lower part or bottom of the lower mold.

[0050] For example, detecting the position of resin at at least one upper resin inlet channel allows for the notification of resin arrival and / or passage through at least one upper resin inlet channel, and control of resin supply through said at least one upper resin inlet channel. Furthermore, detecting the position of resin at at least one additional resin inlet channel allows for the notification of resin arrival and / or passage through said at least one additional resin inlet channel, and control of resin supply through said at least one additional inlet.

[0051] Detecting the position of resin at at least one upper resin inlet channel includes detecting the position of resin behind at least one upper resin inlet channel relative to the resin flow direction.

[0052] Detecting the position of resin at at least one additional resin inlet channel includes detecting the position of resin behind at least one additional resin inlet channel relative to the resin flow direction.

[0053] Alternatively, the position of the resin can be detected at any other location in the upper and lower molds and / or fiber layup.

[0054] According to another embodiment, the pouring of the dry fiber layup in the upper and lower molds begins by supplying resin through at least one upper resin inlet channel. Furthermore, after supplying resin through at least one upper resin inlet channel, the pouring of the dry fiber layup in the upper and lower molds continues by supplying resin through at least one additional resin inlet channel.

[0055] Initiating resin infusion through at least one upper resin inlet channel allows the dry fiber layup in both the upper and lower molds to be wetted primarily by a downward (top-down) resin flow. This reduces or eliminates the need for a significant increase in resin height. Furthermore, the resin flow provided through at least one upper resin inlet channel is supported by additional resin provided through at least one additional resin inlet channel. Therefore, dry fiber layups can be better infused with resin, even for very large blade sizes.

[0056] According to another embodiment, the pouring of the dry fiber layup in the upper and lower molds begins by supplying resin through at least one additional resin inlet channel. Furthermore, after supplying resin through at least one additional resin inlet channel, the pouring of the dry fiber layup in the upper and lower molds continues by supplying resin through at least one upper resin inlet channel.

[0057] Resin infusion, initiated through at least one additional resin inlet channel, allows the dry fiber layup in the upper mold to be wetted primarily by an upward resin flow. Furthermore, the resin flow provided through at least one additional resin inlet channel is supported by additional resin provided through at least one upper resin inlet channel.

[0058] According to another embodiment, if it is detected that resin supplied through one of at least one upper resin inlet channel and at least one additional resin inlet channel has flowed to the other of the at least one upper resin inlet channel and at least one additional resin inlet channel, resin is supplied through said other of the at least one upper resin inlet channel and at least one additional resin inlet channel.

[0059] Detecting that resin has flowed into one of at least one upper resin inlet channel and at least one additional resin inlet channel includes detecting that resin has passed through one of at least one upper resin inlet channel and at least one additional resin inlet channel.

[0060] Cavitation can be avoided by supplying resin only through the inlet when the resin flow has already reached and / or passed through at least one of the upper resin inlet channels and at least one additional resin inlet channel. In particular, cavitation between the converging flow fronts of the at least one upper resin inlet channel and at least one additional resin inlet channel can be avoided. Therefore, the retention of dry zones in the manufactured blades can be better prevented.

[0061] According to another embodiment, the inlet pressure of the resin supplied through at least one upper resin inlet channel and / or at least one additional resin inlet channel is controlled to be below atmospheric pressure.

[0062] Providing resin with an inlet pressure lower than atmospheric pressure allows for better compaction of the fiber layup.

[0063] According to another embodiment, the resin inlet pressure supplied through at least one upper resin inlet channel and / or at least one additional resin inlet channel is controlled such that the pressure in the space between the upper and lower molds is controlled to be below atmospheric pressure.

[0064] For example, the pressure in the space between the upper and lower molds and the vacuum bag is controlled to be lower than atmospheric pressure.

[0065] Specifically, the pressure in the entire space between the upper and lower molds (e.g., the entire space between the upper and lower molds and the vacuum bag) is controlled to be below atmospheric pressure.

[0066] The resin is supplied with inlet pressure so that the space in which the dry fiber layup is drawn in is kept below atmospheric pressure, which allows for better compaction of the fiber layup, even in the lower part and / or bottom of the lower die.

[0067] According to another embodiment, during the resin flow through the dry fiber layup in the upper and lower molds, the inlet pressure of the resin supplied through at least one upper resin inlet channel and / or at least one additional resin inlet channel is reduced.

[0068] Reducing the resin inlet pressure during resin flow through the dry fiber layup in the upper and lower molds allows for compensation of the increased pressure in the space between the upper and lower molds (the space between the upper and lower molds and the vacuum bag) during resin downward flow.

[0069] According to another embodiment, the method includes the steps of: extracting excess resin from the lower part or bottom of the upper mold, from the lower mold and / or from the lower part or bottom of the lower mold.

[0070] Extracting excess resin allows for the prevention of excessive resin (resin lake) in the lower part of the mold.

[0071] According to another embodiment, at least one upper resin inlet channel is arranged only in the longitudinal section of the upper mold that is configured to manufacture the inner blade section of a wind turbine blade.

[0072] In particular, at least one upper resin inlet channel has an elongated channel-like structure and is arranged only along the longitudinal direction of the mold in the longitudinal section of the upper mold that is configured to manufacture the inner blade section of a wind turbine blade.

[0073] Therefore, an additional upper resin inlet channel is only applied when the manufactured blade cross-section has a circular or near-circular cross-section and thus a large height. In other words, for manufacturing the outer blade section, where the blade cross-section has an airfoil shape and thus a smaller height, an additional upper resin inlet channel is avoided.

[0074] The inner leaf section includes, for example, the root section of the manufactured leaf.

[0075] In particular, when the entire wind turbine blade is manufactured using a single upper mold and a single lower mold (either as a single piece or as a longitudinal section), the longitudinal section of the upper mold configured to manufacture the inner blade section includes at least one upper resin inlet channel, while the longitudinal section of the upper mold configured to manufacture the outer blade section does not include any upper resin inlet channel.

[0076] In the presence of two or more upper molds and two or more lower molds as alternatives, the first upper mold configured to manufacture the inner blade section includes at least one upper resin inlet channel, while one or more additional upper molds configured to manufacture one or more additional outer sections do not include any upper resin inlet channel.

[0077] According to another embodiment, at least one upper resin inlet channel is arranged at a height above the lower end of the upper mold, as seen in cross-section, the height corresponding to an angle greater than 15 degrees, greater than 30 degrees, greater than 40 degrees, greater than 45 degrees, greater than 60 degrees, greater than 75 degrees, and / or greater than 80 degrees. The angle is defined between a horizontal plane and a plane including the lower end of the upper mold, the plane intersecting the longitudinal axis of the manufactured blade and at least one upper resin inlet channel.

[0078] At least one upper resin inlet channel is disposed, for example, at the top of the upper mold (e.g., at an angle greater than 75 and / or 90 degrees). In another example, at least one upper resin inlet channel is disposed at an intermediate position between the top and bottom of the upper mold (e.g., at an angle between 30 and 60 degrees).

[0079] According to another aspect, a mold for manufacturing wind turbine blades is proposed. The mold includes a lower mold and an upper mold. Furthermore, at least one upper resin inlet channel is arranged at the upper part of the upper mold.

[0080] The embodiments and features described with reference to the method of the present invention, with necessary modifications, are applicable to the molds of the present invention.

[0081] Other possible embodiments or alternative solutions of the present invention also encompass combinations of features described above or below with respect to the embodiments (not expressly mentioned herein). Those skilled in the art can also add individual or separate aspects and features to the most basic form of the invention. Attached Figure Description

[0082] Other embodiments, features, and advantages of the invention will become apparent from the following description and dependent claims, taken in conjunction with the accompanying drawings, in which:

[0083] Figure 1 A wind turbine according to an embodiment is shown;

[0084] Figure 2 A method for manufacturing according to the first embodiment is shown. Figure 1 A cross-sectional view of the mold for the blades of a wind turbine.

[0085] Figure 3 It shows the relationship with Figure 2 A similar view, but the resin is partially injected into the fiber lay-up arranged in the mold;

[0086] Figure 4 It shows the relationship with Figure 2 A similar view, but with equipment for extracting excess resin;

[0087] Figure 5 It shows Figure 2 A perspective view of a modified mold;

[0088] Figure 6 It shows Figure 2 A perspective view of a modified mold;

[0089] Figure 7 A flowchart is shown illustrating the use of the first embodiment. Figure 2 Mold manufacturing Figure 1 Methods for wind turbine blades;

[0090] Figure 8 A method for manufacturing according to the second embodiment is shown. Figure 1 A cross-sectional view of the mold for the blades of a wind turbine.

[0091] Figure 9 A flowchart is shown illustrating the use of the second embodiment. Figure 8 Mold manufacturing Figure 1 Methods for wind turbine blades; and

[0092] Figure 10 A cross-section of the first embodiment is shown. Figure 2 The mold and according to the second embodiment Figure 8 The geometric arrangement of the resin inlet channel of the mold.

[0093] In the accompanying drawings, unless otherwise indicated, the same reference numerals denote the same or functionally equivalent elements. Detailed Implementation

[0094] Figure 1 A wind turbine 1 according to an embodiment is shown. The wind turbine 1 includes 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 within a nacelle 5. During operation of the wind turbine 1, the blades 3 are driven to rotate by 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 base 7, such as a monopile or tripile. The base 7 is connected to and / or driven into the ground or seabed.

[0095] The following will refer to Figures 2 to 7 An improved method for manufacturing wind turbine blades 3 according to the first embodiment is described.

[0096] Figure 2 The cross-section shows the process of manufacturing. Figure 1 A mold 8 for one of the wind turbine blades 3. Mold 8 includes a lower mold 9 and an upper mold 10.

[0097] In step S1 of the method, the dry fiber layup 11 is arranged in the upper mold 10 and the lower mold 9. The dry fiber layup 11 may also include a core material and / or reinforcing beams (not shown). In addition, a shear web 12 is arranged in the mold 8.

[0098] In addition, the dry fiber layup 11 is covered with one or more vacuum bags 13.

[0099] In step S2 of the method, the upper mold 10 is arranged on the lower mold 9. Figure 2 The mold 8 is shown in a closed state, wherein the upper mold 10 has been arranged on the lower mold 9.

[0100] Note that mold 8 may also include one or more mold cores 14. Figure 2 In the example, two mold cores 14 are shown. The mold cores 14 allow for an improved arrangement of the dry fiber layup 11 in the mold 8 (particularly in the upper mold 10) and an improved arrangement of the shear web 12. Furthermore, the upper mold 10 can be more easily arranged on the lower mold 9. In the case of one or more mold cores 14, each of them is covered, for example, by one of the vacuum bags 13.

[0101] In step S3 of the method, a vacuum is created in the space 15 covered by the vacuum bags 13. The space 15 is specifically the space between the upper mold 10, the lower mold 9, and one or more vacuum bags 13. The space 15 may include the area surrounding the shear web 12.

[0102] The upper mold 10 includes at least one upper resin inlet channel 16. Figure 2 In the example shown, two resin inlet channels 16 are arranged between the dry fiber layup 11 and the vacuum bag 13. These two resin inlet channels 16 are arranged on the mold core 14 covered by the vacuum bag 13. Furthermore, Figure 2 The two upper resin inlet channels 16 are arranged symmetrically with respect to the vertical center line V of the mold 8.

[0103] Each of the upper resin inlet channels 16 has an elongated structure arranged along the longitudinal direction L1 of the mold 8. Figure 5 The longitudinal direction L1 is shown in the figure. In addition, each of the upper resin inlet channels 16 includes an opening at its top along its length, through which resin 17 can be supplied and infused into the dry fiber layup 11.

[0104] In step S4 of the method, resin 17 is started to be supplied to at least one upper resin inlet channel 16, and resin 17 is supplied through the opening of at least one upper resin inlet channel 16. Figure 3 ).

[0105] Resin supplied through the openings of the two upper resin inlet channels 16 is delivered at an inlet pressure lower than atmospheric pressure. The inlet pressure is, for example, slightly lower than atmospheric pressure. The inlet pressure has a value in the range of, for example, 0.6 to 0.95 bar, preferably in the range of 0.8 to 0.95 bar, and even more preferably about 0.9 bar.

[0106] In step S5 of the method, resin 17 supplied through the opening of the upper resin inlet channel 16 is injected into the dry fiber layup 11 due to the vacuum generated in space 15. Specifically, the resin 17 supplied through the opening of the upper resin inlet channel 16 is injected into the dry fiber layup 11 in the upper mold 10.

[0107] Mold 8 includes at least one additional resin inlet channel 18, 19. Figure 2-4 In the example shown, mold 8 includes two additional resin inlet channels 18, 19, arranged in the connection region between upper mold 10 and lower mold 9. The additional resin inlet channel 18 is, for example, a trailing edge resin inlet channel. The additional resin inlet channel 19 is, for example, a leading edge resin inlet channel. Each of the additional resin inlet channels 18, 19 has an elongated structure including an opening along its length.

[0108] exist Figure 2-4 In one example, two additional resin inlet channels 18, 19 are arranged between the upper mold 10 / lower mold 9 and the dry fiber layup 11. In another example, at least one additional resin inlet channel 18, 19 may be arranged between the dry fiber layup 11 and the vacuum bag 13. In yet another example, at least one additional resin inlet channel 18, 19 may be arranged between the upper mold 10 / lower mold 9 and the dry fiber layup 11 (e.g., as shown in the image). Figure 2-4 (as shown), and at least one additional resin inlet channel may be arranged between the dry fiber layup 11 and the vacuum bag 13.

[0109] In step S6 of the method, resin 17 is detected by means of one or more sensors 20, 21 at at least one additional resin inlet channel 18, 19. Figure 3 The position of ).

[0110] Figure 2-4 In the example, sensors 20 and 21 are arranged within the lower mold 9. The lower mold 9 includes a plurality of drill holes 22 and 23, each having an opening toward the inner surface 24 of the lower mold 9. Each of the sensors 20 and 21 is arranged in one of the drill holes 22 and 23 such that the corresponding sensor 20 or 21 is flush with the inner surface 24 of the lower mold 9. The sensors 20 and 21 may also be constructed and arranged differently, for example as an adhesive at the inner surface 24 (i.e., without drill holes in the mold 8).

[0111] Sensors 20 and 21 are, for example, pressure sensors. Sensors 20 and 21 can also be other sensors capable of detecting resin 17.

[0112] Sensor 20 is positioned below the additional resin inlet channel 18 to detect whether the resin 17 supplied through the opening of the upper resin inlet channel 16 has passed through the additional resin inlet channel 18.

[0113] Sensor 21 is positioned below the additional resin inlet channel 19 to detect whether the resin 17 supplied through the upper resin inlet channel 16 has passed through the additional resin inlet channel 19.

[0114] In step S7 of the method, if the flow front of the resin 17 supplied through the upper resin inlet channel 16 is detected by means of sensors 20 and 21 to have reached and passed through the other resin inlet channels 18 and 19, then resin 17 is supplied through the openings of the other resin inlet channels 18 and 19.

[0115] Specifically, in step S7, resin 17 is supplied to additional resin inlet channels 18 and 19, and is supplied through the openings of the additional resin inlet channels 18 and 19 at an inlet pressure lower than atmospheric pressure. The resin supplied through the additional resin inlet channels 18 and 19 is, for example, delivered at an inlet pressure slightly lower than atmospheric pressure. The inlet pressure has a value in the range of, for example, 0.6 to 0.95 bar, preferably in the range of 0.8 to 0.95 bar, and even more preferably about 0.9 bar.

[0116] In addition, in step S7, the supply of resin 17 to the upper resin inlet channel 16 can be shut off.

[0117] In step S8 of the method, the dry fiber lay-up 11 in the lower mold 9 is injected with resin 17 supplied through the upper resin inlet channel 16 and other resin inlet channels 18, 19.

[0118] In step S9 of the method, the inlet pressure of resin 17 supplied through additional resin inlet channels 18, 19 is reduced. The inlet pressure of resin 17 can be reduced continuously or gradually. The inlet pressure of resin 17 is reduced so as to keep the pressure in the entire space 15 (chamber 15) below atmospheric pressure. In particular, the inlet pressure of resin 17 is reduced to compensate for the increase in pressure in space 15 during the downward flow of resin 17.

[0119] Step S9 can be performed throughout the infusion process (e.g., in S5 to S10) whenever it is necessary to adjust the pressure within space 15 to keep the pressure within space 15 below atmospheric pressure.

[0120] In step S10 of the method, the position of the resin 17 is detected by means of one or more sensors 25 at the bottom 26 of the lower mold 9.

[0121] exist Figure 2-4 In the example, two sensors 25 are shown arranged within a drilled hole 27 in the lower mold 9. The sensors 25 are, for example, pressure sensors, but could also be other sensors capable of detecting the position of the resin 17.

[0122] In step S11 of the method, by means of the lower part 28 and / or the bottom 26 of the lower mold 9 ( Figure 4 Excess resin 17" is extracted to treat excess resin 17 in the lower part 28 and / or bottom 26. For example, excess resin 17" is extracted by means of through holes 31, hoses 32, pumps 33 and overflow containers 34 in the lower mold 9.

[0123] Note that in Figure 4 For clarity, the resin 17 that has been infused into the dry fiber layup 11 is not shown.

[0124] Step 11 of the method can be performed throughout the pouring process (e.g., in S8 to S10) whenever excessive resin 17 appears in the lower part of the mold 8.

[0125] In step S12 of the method, a vacuum is applied to the upper resin inlet channel 16 to retain the resin 17 in the upper part 29 and / or top 30 of the upper mold 10.

[0126] Step S12 can be performed simultaneously with any of steps S7 to S11. In particular, step S12 can be performed at the end of the infusion process and / or after the completion of the infusion process (e.g., at the end of S8, after S8, S9, S10 and / or S11).

[0127] Figure 5 It shows Figure 2-4 A variation of at least one upper resin inlet channel 16. Figure 5 A perspective view of the lower mold 9 and two mold cores 14 of mold 8 is shown. For illustrative purposes, the upper mold 10 is... Figure 5 Not shown in the image. Figure 5 In the example, at least one upper resin inlet channel 116 comprises four upper resin inlet channels 116, which are parallel to each other and arranged on the mold core 14 along the longitudinal direction L1 of the mold 8. The longitudinal direction L1 of the mold 8 defines the longitudinal direction of the blade manufactured using the mold 8. Resin is supplied to the four upper resin inlet channels 116 via hose 42, branch 43, and two manifolds 35.

[0128] Figure 5Illustration I shows an extended view of branch 43, manifold 35, and upper resin inlet channel 116.

[0129] exist Figure 5 In the example shown, one branch 43, two manifolds 35, and one hose 42 are illustrated. However, in another example, two hoses, two branches, and no manifolds may be present. In this case, each of the two hoses is fluidly connected to one of the two branches. Furthermore, each of the two branches is fluidly connected to two of the four upper resin inlet channels.

[0130] exist Figure 5 In the example shown, four upper resin inlet channels 116 are illustrated. However, in another example, a different number (even or odd) of upper resin inlet channels may exist.

[0131] In addition, any suitable number of upper resin inlet channels 116, hoses 42, branches 43 and manifolds 35 can be used.

[0132] The method according to the first embodiment can be applied to the manufacture of the entire wind turbine blade 3 ( Figure 1 In this case, the described upper resin inlet channel 16 (or 116) is arranged along the entire upper mold 10. Alternatively, as Figure 6 As shown, the upper mold 10 may include the described upper resin inlet channel 16 (or 116) only in the longitudinal section C1 of the upper mold 10, which is configured to manufacture the inner blade section of the wind turbine blade 3. Section C1 corresponds to, for example, one-third of the entire length L3 of the mold 8. For example, as described in steps S1 to S12, the dry fiber layups 11, 11' in the mold 8 are infused with resin in section C1. For example, the dry fiber layups 11, 11' in the mold 8 are infused with resin in section C2 by supplying resin only through additional resin inlet channels 18 and 19.

[0133] The following will refer to Figure 8 and 9 An improved method for manufacturing wind turbine blades 3 according to a second embodiment is described.

[0134] Apart from the different arrangement of the upper resin inlet channels 37, 38 and the sensors 39, 40, the mold 8' used in the method according to the second embodiment is similar to the mold 8 used in the method according to the first embodiment.

[0135] like Figure 8As shown, in addition to or replacing the upper resin inlet channel 16', the upper mold 10' of the mold 8' according to the second embodiment includes upper resin inlet channels 37 and 38. The upper resin inlet channels 37 and 38 are arranged at an intermediate position between the top 30' and the lower end 41' of the upper mold 10'. Furthermore, the upper resin inlet channels 37 and 38 are, for example, arranged between the dry fiber layup 11 and the vacuum bag 13.

[0136] Furthermore, according to the second embodiment, the upper mold 10' includes sensors 39 and 40 located above the upper resin inlet channels 37 and 38, respectively.

[0137] Steps S1', S2', and S3' of the method according to the second embodiment are similar to steps S1, S2, and S3 of the method according to the first embodiment. Therefore, their description will be omitted.

[0138] In step S4' of the method according to the second embodiment, resin supply begins to at least one additional resin inlet channel, i.e., in Figure 8 In this example, resin is supplied to two additional resin inlet channels 18' and 19'. Furthermore, resin is supplied through openings in the additional resin inlet channels 18' and 19'. Figure 8 (Not shown in the image). Resin is supplied through openings in additional resin inlet channels 18' and 19' at an inlet pressure below atmospheric pressure. The inlet pressure has a value or range similar to, for example, the inlet pressure of resin 17 supplied through upper resin inlet channel 16 in the first embodiment.

[0139] In step S5' of the method according to the second embodiment, resin supplied through additional resin inlet channels 18' and 19' is injected into the dry fiber layup 11' due to the vacuum generated in space 15'. Specifically, the resin supplied through the additional resin inlet channels 18' and 19' flows upward, thereby wetting the dry fiber layup 11' in the upper mold 10'. Furthermore, the resin supplied through the additional resin inlet channels 18' and 19' also flows downward, thereby wetting the dry fiber layup 11' in the lower mold 9'.

[0140] In step S6' of the method according to the second embodiment, the position of resin supplied and flowing upward through additional resin inlet channels 18' and 19' is detected by means of sensors 39 and 40.

[0141] Specifically, sensor 39 is positioned above the upper resin inlet channel 37. Sensor 39 can detect whether resin supplied through the other resin inlet channel 18' and flowing upwards has passed through the upper resin inlet channel 37. Furthermore, sensor 40 can detect whether resin supplied through the other resin inlet channel 19' and flowing upwards has passed through the upper resin inlet channel 38.

[0142] In step S7' of the method according to the second embodiment, if the flow front of the resin supplied through the other resin inlet channels 18' and 19' is detected by means of sensors 39 and 40, and has reached and passed through the upper resin inlet channels 37 and 38 respectively, then resin is supplied through the upper resin inlet channels 37 and 38.

[0143] Specifically, in step S7', resin supply begins to the upper resin inlet channels 37 and 38, and resin (not shown) is supplied through the openings of the upper resin inlet channels 37 and 38. The resin supplied through the upper resin inlet channels 37 and 38 is delivered at an inlet pressure below atmospheric pressure. The inlet pressure has a value or range similar to, for example, the inlet pressure of the resin 17 supplied through the upper resin inlet channel 16 in the first embodiment.

[0144] In step S8' of the method according to the second embodiment, the dry fiber layup 11' in the upper mold 10' is infused with resin supplied through additional resin inlet channels 18' and 19' and through upper resin inlet channels 37 and 38.

[0145] The resin support provided by the upper resin inlet channels 37 and 38 allows the resin to flow upward through the dry fiber layup 11' in the upper mold 10'. Therefore, even in the upper part 29' and / or top 30' of the upper mold 10', the dry fiber layup 11' can be better wetted. Thus, even for very large blades with large cross-sections, points of dryness (i.e., no resin) in the manufactured blade 3 can be better prevented.

[0146] In addition to the upper resin inlet channels 37 and 38, the upper mold 10' according to the second embodiment may also include an upper resin inlet channel 16', such as... Figure 8 As shown. Resin supplied through the optional upper resin inlet channel 16' can further support the infusion of dry fiber lay-up 11' in the upper part 29' and top 30' of the upper mold 10'.

[0147] In addition to sensors 39 and 40, the mold 8' according to the second embodiment may also include other sensors. For example, the mold 8' may include a sensor 25' similar to the sensor 25 of the first embodiment.

[0148] Figure 10 The geometric arrangement of at least one upper resin inlet channel 16 and at least one additional resin inlet channel 18, 19 according to the first embodiment is shown in cross-section. Furthermore, Figure 10The geometric arrangement of at least one upper resin inlet channel 37, 38, an optional at least one upper resin inlet channel 16', and at least one additional resin inlet channel 18', 19' according to the second embodiment is shown in cross-section.

[0149] At least one upper resin inlet channel 16 according to the first embodiment is arranged at the upper part 29 of the upper mold 10. Figure 2-4 In the example shown in 10, at least one upper resin inlet channel 16 includes two upper resin inlet channels 16. Both upper resin inlet channels 16 are arranged at the top 30 of the upper mold 10. Specifically, as in... Figure 2-4 As seen in the cross-sectional view of 10, each of the upper resin inlet channels 16 is arranged at a height H1 above the lower end 41 of the upper mold 10. Figure 2-4 In the example of 10, height H1 corresponds to an angle α1 greater than 80 degrees. Angle α1 is specifically defined between the horizontal plane H and the plane A. The horizontal plane H includes the lower end 41 of the upper mold 10 and / or the boundary line between the lower mold 9 and the upper mold 10. As seen in the cross-section, plane A intersects the longitudinal axis L2 of the manufactured blade and at least one upper resin inlet channel 16.

[0150] At least one upper resin inlet channel 37, 38 according to the second embodiment is arranged at the upper part 29' of the upper mold 10'. Figure 8 and 10 In the example shown, at least one upper resin inlet channel 37, 38 includes two upper resin inlet channels 37 and 38. As in Figure 8 and 10 As seen in the cross-sectional view, each of the upper resin inlet channels 37 and 38 is located at a height H2 above the lower end 41' of the upper mold 10'. Figure 8 and 10 In the example, height H2 corresponds to an angle α2 of approximately 45 degrees. Angle α2 is specifically defined between horizontal plane H and plane B, horizontal plane H including the lower end 41' of upper mold 10'. As seen in the cross-section, plane B intersects the longitudinal axis L2 of the manufactured blade and at least one upper resin inlet channel 37, 38.

[0151] The mold 8' according to the second embodiment may optionally include an upper resin inlet channel 16', such as... Figure 8 and 10 As shown. In Figure 8 and 10 In the example shown, at least one upper resin inlet channel 16' includes two upper resin inlet channels 16', which are constructed and arranged similarly to the upper resin inlet channel 16 according to the first embodiment.

[0152] Although the invention has been described with reference to preferred embodiments, it will be apparent to those skilled in the art that modifications may be made in all embodiments.

Claims

1. A method for manufacturing wind turbine blades (3), comprising the following steps: - The upper mold (10, 10') is arranged (S2, S2') on the lower mold (9, 9'), wherein the dry fiber layup (11, 11') is arranged in the upper mold (10, 10') or in the upper mold (10, 10') and the lower mold (9, 9'). - Apply a vacuum (S3, S3') to the space (15, 15') between the upper mold (10, 10') and the lower mold (9, 9'), and - The dry fiber layup (11, 11') in the upper mold (10, 10') and / or the lower mold (9, 9') is infused (S5, S8) with resin (17), wherein: The infusion (S5, S8) of the dry fiber layup (11) is initiated as follows: resin (S4) is supplied through at least one upper resin inlet channel (16, 16', 37, 38) located at the upper part (29, 29') of the upper mold (10, 10'), and After resin (17) is supplied (S4) through at least one upper resin inlet channel (16), the infusion (S5, S8) of the dry fiber layup (11) continues in such a way that resin (17) is supplied (S7) through at least one additional resin inlet channel (18, 19) located at the upper mold (10, 10') or the lower mold (9, 9') and at a lower height than the at least one upper resin inlet channel (16, 16', 37, 38).

2. The method according to claim 1, comprising the following steps: The position of the resin (17) is detected (S6, S10, S6') during the flow of the resin (17) through the dry fiber layup (11, 11') in the upper mold (10, 10') and the lower mold (9, 9').

3. The method according to claim 2, wherein, The position of the resin (17) is detected (S6, S10, S6') at at least one upper resin inlet channel (16, 16', 37, 38), at at least one other resin inlet channel (18, 18', 19, 19'), and / or at the lower part (28, 28') or bottom (26, 26') of the lower mold (9, 9').

4. The method according to any one of claims 1-3, wherein, When it is detected that the resin (17) supplied (S4, S4') through the at least one upper resin inlet channel (16, S6') has flowed to the at least one additional resin inlet channel (18, 18', 19, 19'), resin (S7, S7') is supplied through the at least one additional resin inlet channel (18, 18', 19, 19').

5. The method according to any one of claims 1-3, wherein, The inlet pressure of the resin (17) supplied through at least one upper resin inlet channel (16, 16', 37, 38) and / or at least one additional resin inlet channel (18, 18', 19, 19') (S4, S4', S7, S7') is controlled to be below atmospheric pressure.

6. The method according to any one of claims 1-3, wherein, The inlet pressure of the resin (17) supplied through at least one upper resin inlet channel (16, 16', 37, 38) and / or at least one additional resin inlet channel (18, 18', 19, 19') (S4, S4', S7, S7') is controlled such that the pressure within the space (15, 15') between the upper mold (10, 10') and the lower mold (9, 9') is controlled to be below atmospheric pressure.

7. The method according to claim 5, wherein, During the flow of the resin (17) through the dry fiber layup (11) in the upper mold (10, 10') and the lower mold (9, 9'), the inlet pressure of the resin (17) supplied through the at least one upper resin inlet channel (16) and / or the at least one additional resin inlet channel (18, 19) is reduced (S9) (S4, S7).

8. The method according to any one of claims 1-3 and 7, comprising the following steps: Excess resin (17") is extracted (S11) from the lower part or bottom of the upper mold (10), from the lower mold (9) and / or from the lower part (28, 28') or bottom (26, 26') of the lower mold (9).

9. The method according to any one of claims 1-3 and 7, wherein, The at least one upper resin inlet channel (16, 16', 37, 38) is arranged only in the longitudinal section (C1) of the upper mold (10) which is configured to manufacture the inner blade section of the wind turbine blade (3).

10. The method according to any one of claims 1-3 and 7, wherein: The at least one upper resin inlet channel (16, 16', 37, 38) is arranged at a height (H1, H2) above the lower end (41, 41') of the upper mold (10, 10'), as seen in the cross-section, where the height (H1, H2) corresponds to an angle (α1, α2) greater than 15 degrees. The angles (α1, α2) are defined between a horizontal plane (H) and a plane (A, B), the horizontal plane (H) including the lower end (41, 41') of the upper mold (10, 10'), and the plane (A, B) intersecting the longitudinal axis (L2) of the manufactured blade and the at least one upper resin inlet channel (16, 16', 37, 38).

11. The method according to any one of claims 1-3 and 7, wherein: The at least one upper resin inlet channel (16, 16', 37, 38) is arranged at a height (H1, H2) above the lower end (41, 41') of the upper mold (10, 10'), as seen in the cross-section, where the height (H1, H2) corresponds to an angle (α1, α2) greater than 30 degrees. The angles (α1, α2) are defined between a horizontal plane (H) and a plane (A, B), the horizontal plane (H) including the lower end (41, 41') of the upper mold (10, 10'), and the plane (A, B) intersecting the longitudinal axis (L2) of the manufactured blade and the at least one upper resin inlet channel (16, 16', 37, 38).

12. The method according to any one of claims 1-3 and 7, wherein: The at least one upper resin inlet channel (16, 16', 37, 38) is arranged at a height (H1, H2) above the lower end (41, 41') of the upper mold (10, 10'), as seen in the cross-section, the height (H1, H2) corresponding to an angle (α1, α2) greater than 40 degrees, and The angles (α1, α2) are defined between a horizontal plane (H) and a plane (A, B), the horizontal plane (H) including the lower end (41, 41') of the upper mold (10, 10'), and the plane (A, B) intersecting the longitudinal axis (L2) of the manufactured blade and the at least one upper resin inlet channel (16, 16', 37, 38).

13. The method according to any one of claims 1-3 and 7, wherein: The at least one upper resin inlet channel (16, 16', 37, 38) is arranged at a height (H1, H2) above the lower end (41, 41') of the upper mold (10, 10'), and as seen in the cross-section, the height (H1, H2) corresponds to an angle (α1, α2) greater than 45 degrees. The angles (α1, α2) are defined between a horizontal plane (H) and a plane (A, B), the horizontal plane (H) including the lower end (41, 41') of the upper mold (10, 10'), and the plane (A, B) intersecting the longitudinal axis (L2) of the manufactured blade and the at least one upper resin inlet channel (16, 16', 37, 38).

14. The method according to any one of claims 1-3 and 7, wherein: The at least one upper resin inlet channel (16, 16', 37, 38) is arranged at a height (H1, H2) above the lower end (41, 41') of the upper mold (10, 10'), as seen in the cross-section, where the height (H1, H2) corresponds to an angle (α1, α2) greater than 60 degrees. The angles (α1, α2) are defined between a horizontal plane (H) and a plane (A, B), the horizontal plane (H) including the lower end (41, 41') of the upper mold (10, 10'), and the plane (A, B) intersecting the longitudinal axis (L2) of the manufactured blade and the at least one upper resin inlet channel (16, 16', 37, 38).

15. The method according to any one of claims 1-3 and 7, wherein: The at least one upper resin inlet channel (16, 16', 37, 38) is arranged at a height (H1, H2) above the lower end (41, 41') of the upper mold (10, 10'), as seen in the cross-section, where the height (H1, H2) corresponds to an angle (α1, α2) greater than 75 degrees. The angles (α1, α2) are defined between a horizontal plane (H) and a plane (A, B), the horizontal plane (H) including the lower end (41, 41') of the upper mold (10, 10'), and the plane (A, B) intersecting the longitudinal axis (L2) of the manufactured blade and the at least one upper resin inlet channel (16, 16', 37, 38).

16. The method according to any one of claims 1-3 and 7, wherein: The at least one upper resin inlet channel (16, 16', 37, 38) is arranged at a height (H1, H2) above the lower end (41, 41') of the upper mold (10, 10'), as seen in the cross-section, where the height (H1, H2) corresponds to an angle (α1, α2) greater than 80 degrees. The angles (α1, α2) are defined between a horizontal plane (H) and a plane (A, B), the horizontal plane (H) including the lower end (41, 41') of the upper mold (10, 10'), and the plane (A, B) intersecting the longitudinal axis (L2) of the manufactured blade and the at least one upper resin inlet channel (16, 16', 37, 38).

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