Wind turbine blade and mold, manufacturing arrangement and method for manufacturing the same

Abstract

A wind turbine blade (3) comprising: a first and a second blade part (C1, C2) connected to each other by thermal welding in an overlap region (24), the first blade part (C1) comprising a blade shell (10); a resistive element (25) arranged in an overlapping region (24) between the first and second blade parts (C1, C2) as a residue of the thermal welding; and an electrically conductive element (27) extending through the blade housing (10) and electrically connected to the resistive element (25) for supplying power (I) to the resistive element (25) during thermal welding. Thus, the first and second blade components may be joined by thermal welding. Furthermore, the resistive element can be heated by a current even when it is difficult to access the resistive element from the inner cavity of the blade, the resistive element serving as a heating element for thermal welding.

Description

Technical Field

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

[0002] Wind turbine blades are typically made of fiber-reinforced resins. For ease of manufacturing, individual blade components are typically prefabricated and the prefabricated components are connected to each other. For example, the pressure side and suction side shells of the blade are manufactured separately and subsequently connected to each other at the leading edge and trailing edge. Furthermore, structural elements such as shear webs, for example, are manufactured separately and subsequently connected to the pressure side and suction side shells of the blade. Known methods for connecting prefabricated blade components to each other include adhesive processes and infusing dry fiber layups with resin in the connection area. Furthermore, US2020 / 0171768 A1 discloses thermal welding for joining blade components. Summary of the invention

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

[0004] According to a first aspect, a wind turbine blade is provided. The wind turbine blade comprises:

[0005] first and second blade parts connected to each other in an overlapping region by heat welding, the first blade part comprising a blade shell;

[0006] a resistance element arranged between the first and second blade parts in the overlapping region as a residue of thermal welding; and

[0007] An electrically conductive element extends through the blade shell and is electrically connected to the resistive element for supplying power to the resistive element during thermal welding.

[0008] Connecting the first and second blade components by heat welding provides a faster joining method compared to a laminate joint, as no curing of epoxy resin is required. Furthermore, heat welding has the advantage over glue joints that adhesives can be avoided, which add significant weight to the blade.

[0009] Furthermore, during the manufacture of the blade, in particular during the thermal welding for providing the joint between the first and second blade parts, the resistive element arranged at the inner side of the blade shell can be heated by an electric current even when the resistive element is difficult to access from the inner side of the blade shell. In particular, the resistive element arranged at the inner side of the blade shell can be supplied with power from a power source arranged at the outer side of the blade shell, i.e. at the outer side. The power source can in particular be arranged at the opposite side of the blade shell with respect to the resistive element.

[0010] For example, in the case of a complete blade shell in a closed state (the complete blade shell comprising the blade shell of the first component), the inner cavity of the complete blade shell may be too small to be (easily) accessible by a worker. In particular, towards the tip region of the blade, the inner cavity becomes smaller and smaller. As a result, it is difficult to electrically connect the resistive element arranged in the inner cavity to a power source from the inside of the cavity. By having the conductive element extending through the blade shell of the first component, an electric current can be guided from the outside of the blade shell (for example, from the outside of the mold in which the blade shell is arranged) through the blade shell (for example, through the mold and the blade shell) to the resistive element. In this way, even a resistive element arranged in a position that is difficult to reach from the inside of the blade can be heated for thermal welding.

[0011] The wind turbine blades are part of the rotor of a wind turbine. The wind turbine is a device that converts the kinetic energy of wind into electrical energy. For example, the wind turbine includes: a rotor with one or more blades, each blade connected to a hub; a nacelle including a generator; and a tower supporting the nacelle at its top end. The tower of the 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.

[0012] The wind turbine blade (e.g., its root portion) is fixedly or rotatably connected to the hub. Except for the (cylindrical) root portion, the wind turbine blade is aerodynamically formed. For example, the wind turbine blade comprises a pressure side (windward side) and a suction side (leeward side). The pressure side and the suction side are connected to each other at a leading edge and a trailing edge. The pressure side and the suction side and the leading edge and the trailing edge define an airfoil of the wind turbine blade.

[0013] The wind turbine blade has a shell (complete shell), for example, which is made of fiber-reinforced resin. For example, the blade shell is manufactured by the following steps: arranging a fiber stack in a mold; infusing the fiber stack with resin; and curing the resin. For example, the complete blade shell surrounds the inner cavity of the blade. For example, the blade shells of the pressure side and the suction side are manufactured separately (for example, in separate upper and lower molds) and connected to each other by heat welding. For example, the wind turbine blade also includes one or more shear webs, which connect the blade shells of the pressure side and the suction side in the inner cavity of the blade. The shear webs provide shear strength to the blade.

[0014] The pressure side shell, the suction side shell, the one or more shear webs and / or other blade components may be prefabricated separately. Subsequently, the prefabricated blade components (eg, the first and second blade components) may be joined to each other by, for example, heat welding.

[0015] Thermal welding includes, for example, thermal resin welding of a weldable resin such as a thermoplastic resin or a weldable thermosetting resin. The thermal welding is, for example, thermoplastic welding.

[0016] In particular, the resistor element is a conductive element. In particular, the resistor element has a first terminal and a second terminal. The resistor element can generate heat by means of an electric current, which is applied to the resistor element and flows between the first terminal and the second terminal of the resistor element. In particular, the resistor element is a heating element. The heat generated by the resistor element depends on the resistance value of the resistor element and the amount of current and / or voltage applied to the resistor element.

[0017] The resistor element may be made of metal. For example, the resistor element is made of copper. Alternatively, the resistor element may be made of carbon fiber.

[0018] The resistor element is arranged between the blade members such that the resistor element is sandwiched between the blade members in an overlapping region.

[0019] The overlap region is the region where a portion of the first blade member overlaps a portion of the second blade member. The overlap region is the joining region of the first and second blade members.

[0020] During manufacture, a thermoplastic resin or weldable thermosetting resin may be disposed between the first and second blade members in an overlapping region, for example in contact with a surface of the first and / or second blade member and / or the resistive element. When the resistive element is heated by applying an electric current through the resistive element, the thermoplastic resin or weldable thermosetting resin melts and / or softens and joins the blade members.

[0021] The electrically conductive element extending through the blade shell of the first blade part is a further remnant of the thermal welding in addition to the electrically resistive element.

[0022] In particular, the conductive element extends from an inner surface of the blade shell through the blade shell to an outer surface of the blade shell.

[0023] The body of the conductive element is for example at least partially embedded in the blade shell of the first component. For example, the conductive element may also be completely embedded in the blade shell of the first component, except for the electrical connection to the resistive element and the power supply / further resistive element of the mould.

[0024] In particular, the conductive element is fixed in a blade shell of the first component.

[0025] The blade shell for example comprises a hole, for example a through hole, in which the conductive element is arranged.For example, the conductive element is cast in the fiber reinforced resin of the blade shell.

[0026] In particular, the electrically conductive element is a connection element for connecting to a matching connection element (eg another electrical connection element of the mould), the matching connection element being arranged at the outer surface of the blade shell.

[0027] For example, the conductive element is a pin or a plug.

[0028] The blade may comprise more than one conductive element, each conductive element extending through the blade shell at a different location of the blade shell for supplying power to one or more resistive elements. For example, the blade may comprise: a first conductive element extending through the blade shell for electrical connection to a first terminal of a resistive element; and a second conductive element extending through the blade shell for electrical connection to a second terminal of the resistive element.

[0029] Alternatively or additionally, the blade may include more than one resistive element, which are electrically connected to each other in series at their respective first terminals and / or second terminals. By using more than one resistive element, the joining between the first blade component and the second blade component via a large bond line can be achieved by thermal welding. In addition, by using more than one resistive element, the voltage required to heat the corresponding resistive element in the resistive elements can be kept low (for example, at or below 690V and / or 220V). In the presence of more than one resistive element, the blade may include more than one conductive element, which extends through the blade shell for supplying power to multiple or all of the resistive elements.

[0030] According to an embodiment of the first aspect, the conductive element extending through the blade shell is arranged outside the overlapping area and / or the conductive element is electrically connected to the resistive element by means of a cable.

[0031] For example, the cables (wires) are arranged at the inner surface of the blade shell.

[0032] According to a further embodiment of the first aspect, the electrically conductive element extending through the blade shell comprises a first end electrically connected to the resistive element and a second end for releasably electrically connecting to a power source.

[0033] For example, the first end of the conductive element is electrically connected to the resistive element by means of a cable.

[0034] In particular, the second end of the conductive element is electrically connected to a power source for the welding process, and is disconnected from the power source after the welding process is completed.

[0035] In particular, a first end of the conductive element is arranged at an inner surface of the blade shell and a second end is arranged at an outer surface of the blade shell.

[0036] According to a further embodiment of the first aspect, the second end of the conductive element of the blade shell is configured for releasable electrical connection to another conductive element of a mould configured for manufacturing the blade shell and the another conductive element is configured for electrical connection to a power source.

[0037] This has the advantage that the electrical connection of the resistive element can be simplified by providing the electrical connection to the power source via another conductive element of the mould. In particular, the first part with the blade shell can be manufactured in a mould which can also be used to provide the electrical connection to the power source during thermal welding.

[0038] According to another embodiment of the first aspect, the second end of the electrically conductive element of the blade shell is configured for electrical connection to another electrically conductive element of the mould by:

[0039] Threaded connection;

[0040] matching surfaces of the conductive element and another conductive element;

[0041] applying pressure to press the conductive element and the further conductive element towards each other; and / or

[0042] Plug connection.

[0043] Hereby, a releasable electrical connection between an electrically conductive element of the blade shell and another electrically conductive element of the mould may be achieved in a simple manner.

[0044] According to another embodiment of the first aspect,

[0045] The blade comprises an electrically conductive element in an outer part of the blade shell, and / or

[0046] The blade comprises an electrically conductive element only in an outer portion of the blade shell, and

[0047] The outer portion of the blade shell extends from the tip end of the blade in the direction of the root end of the blade for a length that is 80% or less, 70% or less, 60% or less, 50% or less, and / or 40% or less of the total blade length.

[0048] The blade thus allows supplying power to the resistance element from outside the blade in a portion of the blade in which the inner cavity of the blade is relatively small and difficult to access.

[0049] According to another embodiment of the first aspect,

[0050] The second blade component comprises: another blade shell or structural element, a reinforcing beam, a web and / or a shear web; and / or

[0051] The blade shell and / or the further blade shell comprises: a blade half shell, a lower blade shell, an upper blade shell, a pressure side shell and / or a suction side shell.

[0052] According to a second aspect, a mold for manufacturing the above wind turbine blade is provided. The mold comprises:

[0053] a molding surface for molding the first blade component, the first blade component comprising the blade shell and a conductive element extending through the blade shell and connected to a resistive element of the blade; and

[0054] Another conductive element is exposed at the molding surface, and is used to be electrically connected with the conductive element of the blade shell to supply power to the resistance element for thermal welding.

[0055] For example, the mould is a mould for producing a blade half-shell.

[0056] For example, the further electrically conductive element extends from the molding surface through the body of the mold to another surface of the mold body arranged opposite to the molding surface.

[0057] For example, the further electrically conductive element is removable from the mould body or permanently fixed to the mould body.

[0058] According to a third aspect, a manufacturing arrangement for manufacturing a wind turbine blade is provided. The manufacturing arrangement comprises: a blade as described above and a mould as described above. Furthermore, a conductive element of the blade shell is electrically connected to another conductive element of the mould to supply power to a resistive element of the blade for thermal welding.

[0059] For example, the manufacturing arrangement includes a power supply electrically connected to another conductive element of the mold. In the case of more than one resistive element, the manufacturing arrangement may include more than one power supply electrically connected to the more than one resistive element, respectively.

[0060] According to a fourth aspect, a method for manufacturing a wind turbine blade is provided. The method comprises the following steps:

[0061] a) arranging first and second blade members so that they overlap each other in an overlap region, wherein the first blade member comprises a blade shell and a conductive element extending through the blade shell, a resistive element is arranged between the first and second blade members in the overlap region and the resistive element is connected to the conductive element; and

[0062] b) connecting the first and second blade components to each other by thermal welding, comprising supplying power to the resistive element through an electrically conductive element of the blade shell for heating the resistive element.

[0063] According to an embodiment of the fourth aspect,

[0064] Step a) comprises closing the complete shell of the blade by arranging the first blade part on the second blade part or arranging the first blade part on another blade part, and

[0065] Step b) is performed in the closed state of the complete blade shell.

[0066] In particular, the closed state of the complete blade shell refers to a state in which the complete blade shell is closed relative to the cross section of the complete blade shell. In particular, the closed state of the complete blade shell refers to a state in which the inner cavity enclosed by the complete blade shell can only be approached from an opening in the longitudinal direction of the blade (such as an opening located at the root end portion of the blade). In particular, the closed state of the complete blade shell refers to a state in which the complete blade shell is closed by arranging blade parts (such as two half shells) on top of each other but the blade parts do not yet need to be bonded to each other.

[0067] According to another embodiment of the fourth aspect, the method comprises the following steps:

[0068] providing a mold having a molding surface and another conductive element exposed at the molding surface; and

[0069] providing a first blade member having an electrically conductive element extending through a blade shell of the first blade member;

[0070] Therein, in step b), power is supplied to the resistive element via another conductive element of the mould and a conductive element of the blade shell.

[0071] According to another embodiment of the fourth aspect, the method comprises the step of manufacturing the first blade component by infusing the fiber layup arranged in a mold and the conductive element at least partially embedded in the fiber layup with resin; and curing the resin.

[0072] According to another embodiment of the fourth aspect, the method comprises the following steps performed before step a):

[0073] arranging the resistor element at the first blade part having the blade shell; and

[0074] The conductive element of the blade shell is electrically connected to the resistive element.

[0075] For example, the conductive element of the blade shell is electrically connected to the resistive element via a cable.

[0076] In particular, the conductive element of the blade shell is electrically connected to the resistive element before closing the complete blade shell.

[0077] According to another embodiment of the fourth aspect, the method comprises the following steps, performed before step a): electrically connecting the electrically conductive element of the blade shell to a power source; and / or electrically connecting another electrically conductive element of the mould to the power source.

[0078] The embodiments and features described with reference to the wind turbine blade of the invention apply mutatis mutandis to the mould, the manufacturing arrangement and the method of the invention and vice versa.

[0079] Other possible implementations or alternatives of the present invention also include such combinations not explicitly mentioned herein, which are combinations of features described above or below with respect to the embodiments. Those skilled in the art may also add separate or isolated aspects and features to the most basic form of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Other embodiments, features and advantages of the present invention will become apparent from the subsequent description and the dependent claims taken in conjunction with the accompanying drawings, in which:

[0081] Figure 1 A wind turbine according to an embodiment is shown;

[0082] Figure 2 It shows that according to the embodiment Figure 1 a cross-sectional view of a wind turbine blade of a wind turbine;

[0083] Figure 3 Shows Figure 2 Detailed view of Section III;

[0084] Figure 4 The arrangement of a resistive element used as a heating element for joining by heat welding is illustrated Figure 2 a blade component of a blade;

[0085] Figure 5 shows the steps during the manufacturing process Figure 2 A lower blade mold and a lower blade shell;

[0086] Figure 6 shows the steps during the manufacturing process Figure 2 An upper blade mold and an upper blade shell;

[0087] Figure 7 Shows Figure 2 Another embodiment of the upper mold of the blade and the upper blade shell;

[0088] Figure 8 Shows Figure 2 Another embodiment of the upper mold of the blade and the upper blade shell;

[0089] Fig. 9 Shows Figure 2 Another embodiment of the upper mold of the blade and the upper blade shell;

[0090] Fig.10 Shown with Figure 6 A similar view with a resistance element arranged in the upper blade shell, the resistance element acting as a heating element for thermal welding;

[0091] Fig.11 Shown with Fig.10 a similar view with a power source electrically connected to said resistive element;

[0092] Fig.12 Shown with Fig.11 a similar view with the joint established between the upper blade shell and the shear web; and

[0093] Fig.13 A flow chart is shown, which illustrates a method for manufacturing a Figure 1 A method for a wind turbine blade of a wind turbine.

[0094] In the drawings, like reference numbers indicate identical or functionally equivalent elements unless otherwise indicated. DETAILED DESCRIPTION

[0095] Figure 1 A wind turbine 1 according to an embodiment is shown. The wind turbine 1 comprises a rotor 2 having one or more blades 3, which are connected to a hub 4. The hub 4 is connected to a generator (not shown) arranged inside a nacelle 5. During operation of the wind turbine 1, the blades 3 are driven to rotate by the wind, and the kinetic energy of the wind is converted into electrical energy by the generator in the nacelle 5. The nacelle 5 is arranged at the upper end of a tower 6 of the wind turbine 1. The tower 6 stands on a foundation 7, such as a monopile or a concrete foundation. The foundation 7 is connected to and / or driven into the ground or seabed.

[0096] Figure 2 Show Figure 1 A cross-sectional view of a wind turbine blade 3 of a wind turbine 1 .

[0097] The blade 3 comprises a complete blade shell 8, which comprises a lower blade shell 9 and an upper blade shell 10. The lower blade shell 9 and the upper blade shell 10 are the lower blade shell and the upper blade shell relative to the manufacturing position. The lower blade shell 9 is, for example, a pressure side shell, and the upper blade shell 10 is, for example, a suction side shell, or vice versa. The complete blade shell 8 surrounds an inner cavity 11 of the blade 3.

[0098] The blade 3 further comprises one or more structural elements 12 extending in the longitudinal direction L1 of the blade 3. The longitudinal direction L1 of the blade 3 is, for example, from the root end 34 ( Figure 4 ) points to the tip 35 of the blade 3 ( Figure 4 ). The structural element 12 preferably comprises a fiber composite material, in particular a glass fiber mat. The structural element 12 may be a shear web, a spar cap, etc. Figure 2 In the figure, a shear web 13 is shown as an example of a structural element 12. Although not shown in the figure, the blade 3 may also include more than one shear web 13. The shear web 13 connects the blade shells 9 and 10 on the pressure side and the suction side in the inner cavity 11 of the blade 3 and provides shear strength for the blade 3. The shear web 13 includes two flanges 14 and 15 attached to the inner surfaces 16 and 17 of the shells 9 and 10, respectively.

[0099] For example, the blade 3 is assembled from a plurality of prefabricated blade components C1, C2, C3, such as the lower blade shell 9, the upper blade shell 10, the structural element 12 and / or the shear web 13. For example, such prefabricated blade components C1-C3 may be connected to each other at joints 18, 19, 20, 21 by thermal welding. For example, the lower blade shell 9 is connected to the upper blade shell 10 in a first joint 18 and a second joint 19 by thermal welding. In particular, the first and second connection areas 18, 19 are arranged at the leading edge 22 and the trailing edge 23 of the blade 3. Although Figure 2 Not shown, the lower and upper blade shells 9, 10 may overlap each other at the joints 18, 19. Furthermore, the structural element 12, such as the shear web 13, is connected to the lower blade shell 9 in a third joint 20 by heat welding and / or to the upper blade shell 10 in a fourth joint 21 by heat welding.

[0100] Hereinafter, the fourth joint 21 between the shear web 13 and the upper blade shell 10 implemented by thermal welding is exemplarily described. However, the following description may also be applicable to one, more or all of the other joints 18, 19, 20.

[0101] Figure 3 Show Figure 2 Detailed view of Section III. Figure 3 Visible in the figure are parts of the shear web 13 including its upper flange 15 and parts of the upper blade shell 10. The upper blade shell 10 is an example of a first blade component C1. Furthermore, the shear web 13 is an example of a second blade component C2. The shear web 13 and the upper blade shell 10 are connected to each other in an overlapping area 24 by thermal welding. In order to provide the heat required for thermal welding, the blade 3 comprises a resistance element 25. The resistance element 25 is arranged during manufacturing between the shear web 13, in particular the upper flange 15 of the shear web 13, and the upper blade shell 10 in the overlapping area 24. Furthermore, as Figure 3 It can be seen that the resistor element 25 remains in the blade 3 after the manufacturing process. Figure 3 It is also shown that during the manufacturing process a weldable resin 26 is arranged between the shear web 13 , in particular the upper flange 15 of the shear web 13 , and the upper blade shell 10 in the overlap region 24 .

[0102] In order to join the two blade parts C1, C2, the resistive element 25 is heated by supplying power I (current I) to the resistive element 25. As the resistive element 25 may be difficult to access from the inner cavity 11 of the blade 3 (particularly when the cavity 11 is narrow with respect to the tip region of the blade 3), the blade 3 comprises a conductive element 27 extending through the blade shell 10 for accessing the resistive element 25 from the outside 28 of the blade shell 10 (i.e. from the outside 28 of the complete blade shell 8, Figure 2 ) supplies power I.

[0103] The conductive element 27 is at least partially embedded in the blade shell 10. The blade shell 10 with the conductive element 27 is for example manufactured by infusing a fiber layup with resin together with the conductive element 27 at least partially embedded in the fiber layup, and curing the resin. The conductive element 27 extends for example from the inner surface 17 of the blade shell 10 to the outer surface 29 of the blade shell 10.

[0104] The conductive element 27 is electrically connected to the resistive element 25 (ie, to a terminal 31 of the resistive element 25 ), for example, by means of a cable 30 .

[0105] The resistance element 25, which was used as a heating element for the welding process during manufacture, remains as a residue of the welding process in the blade 3. Furthermore, the conductive element 27 and the electrical connection 30 (cable 30) also remain in the blade 3 as residues of the welding process.

[0106] To avoid flashover during lightning conditions, the resistive element 25 (and therefore the conductive element 27 and the electrical connection 30) is electrically connected (reference numeral 32) to a lightning rod 33. Thereby, the conductive residues 25, 27, 30 of the welding process may be incorporated into a lightning protection system (not shown) of the blade 3.

[0107] exist Figure 3 In the figure, reference numeral E1 represents a first end of the conductive element 27 , and reference numeral E2 represents a second end of the conductive element 27 .

[0108] like Figure 4 As shown in , the blade 3 may include two or more resistor elements 25, 25' electrically connected to each other in series. Even when the thermal welding process is performed for a long bond line, the use of more than one resistor element 25, 25' allows the resistor elements 25, 25' to be heated more easily. In particular, since the length L of the blade 3 may be as long as 100 meters or more, the use of a plurality of resistor elements 25, 25' is advantageous.

[0109] exist Figure 4, the root end 34 and the tip end 35 of the blade 3 are illustrated. In addition, five resistor elements 25, 25' electrically connected to each other in series are shown as an example. Each resistor element 25, 25' has a first terminal and a second terminal 31, 36, which are used to connect to the adjacent resistor element 25, 25' and the power supply 58 ( Fig.11 ) electrical connection. Figure 4 In the diagram, only the first and second terminals 31 , 36 of the resistor element 25 are denoted by reference numerals.

[0110] Since the inner cavity 11 of the blade 3 becomes increasingly difficult to access as the tip 35 of the blade 3 is approached, the blade 3 may include such means (i.e., the conductive element 27 and the electrical connector 30, Figure 3 ), the device is used to supply power I to the resistive element 25 from, in particular, the outer portion 28 of the blade 3 and / or only in the outer portion 37 of the blade 3. The outer portion 37 of the blade 3 may extend from the blade tip 35 in the direction D of the root end 34 of the blade 3 for a length L2, which is 80% or less, 70% or less, 60% or less, 50% or less and / or 40% or less of the total blade length L. Reference R denotes the maximum radius (or maximum height) of the inner cavity 11, which is considered to be accessible from the inside of the blade 3.

[0111] It should be noted that Figure 2 Can be considered as Figure 4 Cross-sectional view along line AA.

[0112] In the following, reference will be made to Figures 5 to 13 A method for manufacturing the blade 3, in particular for joining the blade parts C1-C3 ( Figure 2 ) method.

[0113] In the following, the fourth joint 21 ( Figure 2 ). However, the method described below can also be applied to the other joints 18, 19, 20 ( Figure 2 ) one, more or all of the ).

[0114] like Figure 5 As shown, in the first step S1 of the method, a lower mold 38 is provided for manufacturing a lower half shell 9. In particular, a fiber layup is arranged in the lower mold 38 and infused with resin to prefabricate the lower half shell 9.

[0115] like Figure 5As shown, in the second step S2 of the method, the prefabricated lower shell 9 is joined to the prefabricated shear webs 12, 13 by thermal welding. In particular, the resistor element 39, the weldable resin ( Figure 5 The shear web 13 is arranged on the lower shell 9. The resistor element 39 is electrically connected to a power source 41, for example, via a cable 40. It should be noted that Figure 5 , only one of the two electrical connections between the power source 41 and the resistor element 39 is visible. Power is supplied to the resistor element 39, which is heated, thereby melting or softening the weldable resin to provide a joint between the lower shell 9 and the shear web 13.

[0116] In this manufacturing state, only the lower shell 9 is present and the upper shell 10 has not yet been formed. As a result, the electrical connection of the power source 41 to the resistor element 39 can be easily made from inside the shell 9. It is therefore not necessary to use conductive elements extending through the blade shell 9, such as Figure 2 The element 27 extending through the shell 10. However, in an embodiment, such an electrically conductive element extending through the blade shell 9 can also be used to join the lower shell 9 with the web 13.

[0117] like Figure 6 As shown, in the third step S3 of the method, the upper shell 10 is prefabricated. In particular, an upper mold 42 is provided, the fiber stack together with the conductive element 27 is arranged on the molding surface 43 of the upper mold 42, and is infused with resin to prefabricate the upper half shell 10, which has the conductive element 27 extending through the shell 10.

[0118] The upper mold 42 includes another conductive element 44 exposed at the molding surface 43, and the other conductive element is used to electrically connect with the conductive element 27 of the blade shell 10. After the electrical contact provided by the conductive element 27 of the shell 10 and the other conductive element 44 of the mold 42, the power supply 58 ( Fig.11 ) can be directed so that the power I spans the die 42 and the housing 10 and is supplied to the resistor element 25 for thermal welding.

[0119] The blade shell 10 with the electrically conductive element and the mould 42 with the further electrically conductive element 44 together form a manufacturing arrangement 45 for manufacturing the wind turbine blade 3 .

[0120] exist Figure 6, a first embodiment of the conductive element 27 and the further conductive element 44 is shown. Electrical contact between the elements 27, 44 may be provided by applying a pressure P so that the elements 27, 44 are pressed against each other at matching surfaces 46, 47 of the elements 27 and 44, respectively.

[0121] Figures 7 to 9 Further embodiments of the electrically conductive element 27 and the further electrically conductive element 44 are shown.

[0122] In the second embodiment of the conductive element 127 of the housing 110 ( Figure 7 ), the body 48 of the conductive element 127 is cast in the housing 110 so that it is exposed to the outer surface 129 of the housing 110 (such as, Figure 2 The conductive element 127 is provided at the outer surface 29 of the housing 10 in the middle, for making electrical contact with the other conductive element 144. In addition, the body 48 of the conductive element 127 is cast in the housing 110 so that it is embedded at the inner surface 117 of the housing 110. The conductive element 127 also includes an electrical connector 49 for connecting to the resistive element 25. The electrical connector 49 is provided, for example, by drilling a hole in the housing 110 and inserting a cable or a conductive pin, etc.

[0123] In the other conductive element 44 ( Figure 6 ) In contrast, the further conductive element 144 of the mould 142 of the second embodiment comprises a different geometry. The further conductive element 144 of the mould 142 comprises a stepped profile 50 towards the moulding surface 143. Having the stepped profile 50 improves the vacuum conditions during vacuum induced resin infusion for casting the blade shell 110.

[0124] In the third embodiment of the conductive element 227 of the housing 210 ( Figure 8 ), the body 51 of the conductive element 227 is cast in the housing 210 so that it is completely embedded in the housing 210. The conductive element 227 also includes electrical connectors 52, 53, which are used to connect to the resistor element 25 and the power source 58 respectively.

[0125] The other conductive element 144 of the mold 142 of the third embodiment is different from the second embodiment ( Figure 7 ) is the same as ).

[0126] In the fourth embodiment of the conductive element 327 of the housing 310 ( Fig. 9 ), the body 54 of the conductive element 327 is cast in the housing 310 so that it is exposed to the outer surface 329 (such as, Figure 2The outer surface 29 of the housing 10 is used to make electrical contact with the other conductive element 344. In addition, the body 54 of the conductive element 327 is cast in the housing 310 so that it is also exposed at the inner surface 317 of the housing 310 for making electrical contact with the resistive element 25. Fig. 9 , the body 54 of the conductive element 327 is shown protruding from the inner surface 317 of the housing 310. However, in other examples, the body 54 of the conductive element 327 may also be flush with the inner surface 317.

[0127] The conductive element 327 (particularly, the body 54 of the conductive element 327) includes two holes 55, 56 with threads 57. Fig. 9 In the embodiment, only the thread 57 in the hole 55 is indicated by a reference numeral for illustrative purposes. The threaded hole 55 is configured to make an electrical connection with the resistor element 25 (e.g., Figure 3 The other threaded hole 56 is configured to be electrically connected to the power source 58 via the other conductive element 344. In particular, the other conductive element 344 according to the fourth embodiment includes a threaded portion 57 with an external thread for engaging the threaded hole 56 of the conductive element 327 (threaded connection T).

[0128] It should be noted that, if appropriate, the features described with respect to any of the first to fourth embodiments of the conductive element 27, 127, 227, 327 and the further conductive element 44, 144, 344 may be applied to any other of the first to fourth embodiments. For example, the element 27, 127, 227 may also include one or more threaded holes similar to the element 327 for making electrical connections (and mechanical connections).

[0129] In the fourth step S4 of the method, Fig.10 As shown in FIG. 1 , a resistive element 25 is provided and an electrical connection of the resistive element 25 is established. In particular, the conductive element 27 of the housing 10 and another conductive element 44 of the mold 42 are electrically connected to each other. According to the embodiments of the conductive elements 27 and 44 (see Figures 6 to 9 ), this electrical connection is achieved by applying a pressure P (e.g. Figure 6 ) or by threaded connections (e.g. Fig. 9 ) or established by other means.

[0130] Furthermore, in step S4, the resistor element 25 (and the weldable resin not shown) is arranged on the upper case 10 ( Fig.10 ). Then, the resistor element 25 is electrically connected to the conductive element 27, for example, by means of a cable 30. For example, the cable 30 is arranged (for example, laid) on the inner surface 17 of the upper housing 10 and fixed thereto.

[0131] Furthermore, a power source 58 is provided and electrically connected to another conductive element 44 of the mold 42 .

[0132] In the fifth step S5 of the method, Fig.11 As shown, the upper shell 10 in the upper mold 42 is turned upside down and arranged on the lower shell 9 and the web 13 in the lower mold 38. Thus, the complete blade shell 8 ( Figure 2 ) is closed.

[0133] In other embodiments, it is also possible to keep the upper shell 10 in its original position, turn the lower shell 9 and the web 13 upside down and arrange them on the upper shell 10 .

[0134] In the sixth step S6 of the method, the upper shell 10 and the web 13 are mechanically connected to each other by thermal welding. In particular, a current I is supplied from the power source 58 and flows through the cable 59, the other conductive element 44 of the mold, the conductive element 27 of the shell 10, the cable 30 and flows to the resistance element 25 for heating the resistance element 25. In this way, a mechanical joint 21 between the upper shell 10 and the web 13 is established.

[0135] Furthermore, the joints 18 and 19 between the upper housing 10 and the lower housing 9 may also be established in a manner similar to the joint 21 .

[0136] In a seventh step S7 of the method, the power source 58 is removed as well as the electrical connection 59 from the power source 58 to the further conductive element 44 of the upper mold 42 .

[0137] Although the invention has been described in terms of preferred embodiments, it will be apparent to those skilled in the art that modifications are possible in all embodiments.

Claims

1. A wind turbine blade (3), comprising: a first and a second blade component (C1, C2) connected to each other in an overlapping region (24) by thermal welding, the first blade component (C1) comprising a blade shell (10); a resistance element (25) arranged between the first and second blade parts (C1, C2) in the overlapping region (24) as a residue of thermal welding; as well as An electrically conductive element (27) extending through the blade shell (10) and electrically connected to the resistive element (25) for supplying power (I) to the resistive element (25) during thermal welding.

2. A wind turbine blade (3) according to claim 1, wherein the conductive element (27) extending through the blade shell (10) is arranged outside the overlapping area (24), and / or the conductive element (27) is electrically connected to the resistive element (25) via a cable (30).

3. A wind turbine blade (3) according to claim 1 or 2, wherein: The conductive element (27) extending through the blade shell (10) comprises a first end (E1) electrically connected to the resistive element (25), and a second end (E2) for releasably electrically connecting to a power source (58).

4. The wind turbine blade (3) according to claim 3, wherein: The second end (E2) of the conductive element (27) of the blade shell (10) is configured to be releasably electrically connected to another conductive element (44) of a mold (42), the mold (42) being configured for manufacturing the blade shell (10), and the another conductive element (44) being configured for being electrically connected to the power source (58).

5. The wind turbine blade (3) according to claim 4, wherein: The second end (E2) of the conductive element (27) of the blade shell (10) is configured to be electrically connected to another conductive element (44) of the mold (42) by: Threaded connection (T); matching surfaces (46, 47) of the conductive element (27) and another conductive element (44); applying a pressure (P) to press the conductive element (27) and the further conductive element (44) toward each other; and / or Plug connection.

6. A wind turbine blade (3) according to any one of claims 1 to 5, wherein: The blade comprises an electrically conductive element (27) in an outer portion (37) of the blade shell (10); and / or The blade comprises the conductive element (27) only in an outer portion (37) of the blade shell (10); and The outer portion (37) of the blade shell (10) extends from the tip end (35) of the blade in the direction (D) of the root end (34) of the blade for a length (L2), wherein the length (L2) is 80% or less, 70% or less, 60% or less, 50% or less and / or 40% or less of the total blade length (L).

7. A wind turbine blade (3) according to any one of claims 1 to 6, wherein: The second blade component (C2, C3) comprises: another blade shell (9) or a structural element (12), a reinforcing beam, a web (13) and / or a shear web (13), and / or The blade shell (10) and / or the further blade shell (9) comprises: a blade half shell (9, 10), a lower blade shell (9), an upper blade shell (10), a pressure side shell and / or a suction side shell.

8. A mould (42) for manufacturing a wind turbine blade (3) according to any one of claims 1 to 7, comprising: a molding surface (43) for molding the first blade component (C1), the first blade component (C1) comprising the blade shell (10) and a conductive element (27), the conductive element (27) extending through the blade shell (10) and connected to the resistive element (25) of the blade (3); and Another conductive element (44) exposed at the molding surface (43) is used to electrically connect to the conductive element (27) of the blade shell (10) to supply power (I) to the resistor element (25) for thermal welding.

9. A manufacturing arrangement (45) for manufacturing a wind turbine blade (3), comprising a blade (3) according to any one of claims 1 to 7 and a mould (42) according to claim 8, wherein: The conductive element (27) of the blade shell (10) is electrically connected to another conductive element (44) of the mold (42) to supply power (I) to the resistive element (25) of the blade (3) for thermal welding.

10. A method for manufacturing a wind turbine blade (3), comprising the following steps: a) arranging (S5) a first and a second blade component (C1, C2) such that the first and second blade components overlap each other in an overlap region (24), wherein the first blade component (C1) comprises a blade shell (10) and an electrically conductive element (27) extending through the blade shell (10), wherein a resistive element (25) is arranged between the first and second blade components (C1, C2) in the overlap region (24), and the resistive element (25) is electrically connected to the electrically conductive element (27), and b) connecting (S6) the first and second blade components (C1, C2) to each other by thermal welding, comprising: supplying power (I) to the resistance element (25) through a conductive element (27) of the blade shell (10) for heating the resistance element (25).

11. The method according to claim 10, wherein: Step a) comprises closing the complete blade shell (8) of the blade (3) by arranging the first blade part (C1) on the second blade part (C3) or by arranging the first blade part (C1) on another blade part (C3), and Step b) is performed in the closed state of the complete blade shell.

12. The method according to claim 10 or 11, comprising the following steps: providing (S3) a mold (42) having a molding surface (43) and another conductive element (44) exposed at the molding surface (43); and providing (S3) the first blade component (C1) having a conductive element (27), the conductive element (27) extending through a blade shell (10) of the first blade component; Therein, in step b), power (I) is supplied to the resistive element (25) via the further conductive element (44) of the mould (42) and the conductive element (27) of the blade shell (10).

13. A method according to any one of claims 10 to 12, comprising the step of manufacturing the first blade component (C1) by infusing a fiber layup arranged in a mold (42) and an electrically conductive element (27) at least partially embedded in the fiber layup with resin, and curing the resin.

14. The method according to any one of claims 10 to 13, comprising the following steps performed before step a): Arranging (S4) the resistor element (25) at the first blade part (C1) having the blade shell (10); and The conductive element (27) of the blade shell (10) is electrically connected (S4) to the resistive element (25).

15. The method according to any one of claims 10-14, comprising the following steps performed before step a): electrically connecting (S4) the conductive element (27) of the blade shell (10) to a power source (58); and / or electrically connecting (S4) the other conductive element (44) of the mold (42) to the power source (58).

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