Method for assembling a rotor blade of a wind turbine

Abstract

A method for assembling rotor blades (5) of a wind turbine (1), the method comprising the steps of: a) providing (S1) at least two different rotor blade modules (23, 25), the rotor blade modules (23, 25) segmenting the rotor blade (5) along the longitudinal direction (L) of the rotor blade (5), wherein each rotor blade module (23, 25) has an inclined interface segment (24, 26, 53, 54), and wherein the inclined interface segment (24, 26, 53, 54) comprises a weldable thermoplastic resin and / or a weldable thermosetting resin (M); b) providing (S2) a resistive element (27); c) arranging (S3) the rotor blade modules ( 23, 25) and the resistive element (27) are arranged such that the inclined interface sections (24, 26, 53, 54) face each other, and the resistive element (27) is sandwiched between the inclined interface sections (24, 26, 53, 54), d) powering the resistive element (27) (S4) to apply heat (H) to the weldable thermoplastic resin and / or the weldable thermosetting resin (M) to melt or soften it, and e) joining the inclined interface sections (24, 26, 53, 54) together at the joint (28, 55) by means of the melted or softened weldable thermoplastic resin and / or weldable thermosetting resin (M) to form the rotor blade (5). This method has the advantage that the rotor blade (5) can be transported to the construction side of the wind turbine (1) in a disassembled state and can be assembled on site. This simplifies the transportation of the rotor blade (5). In addition, the additional fasteners such as bolts used to connect the rotor blade modules (23, 25) together are consumable.

Description

Technical Field

[0001] This invention relates to a method for assembling rotor blades for a wind turbine. Background Technology

[0002] One trend in the wind energy sector is the production of longer rotor blades to reduce energy costs. This presents significant challenges in transporting and handling these blades at installation sites, potentially leading to substantial increases in logistical costs. To mitigate this issue, segmented, modular, or separate rotor blade designs can be employed. These designs are based on customized connection schemes between different substructures. Utilizing this concept, multiple rotor blade segments can be transported individually.

[0003] To date, the choice of hollow structures for field-jointed rotor blades has been separable mechanical joints using T-bolts, stud connections, or fasteners, which can lead to rust problems, lightning attraction, and large joint weight. Even though they are quick and easy to assemble, they require some maintenance and are expensive. Adhesive bonding offers structural and economic efficiency. However, field assembly presents a significant problem in terms of high installation costs due to the need for specialized equipment and additional time-consuming tasks during field assembly to achieve a high-quality bond. Summary of the Invention

[0004] One object of the present invention is to provide an improved method for assembling rotor blades of a wind turbine.

[0005] Therefore, a method for assembling rotor blades for a wind turbine is provided. The method includes the following steps: a) providing at least two different rotor blade modules that segment the rotor blades along the longitudinal direction of the rotor blades, wherein each rotor blade module has an inclined interface section, and wherein the inclined interface section comprises a weldable thermoplastic resin and / or a weldable thermosetting resin; b) providing a resistive element; c) arranging the rotor blade modules and the resistive element such that the inclined interface sections face each other and the resistive element is sandwiched between the inclined interface sections; d) energizing the resistive element to apply heat to the weldable thermoplastic resin and / or the weldable thermosetting resin to melt or soften it; and e) joining the inclined interface sections together at a joint by means of the melted or softened weldable thermoplastic resin and / or weldable thermosetting resin to form a rotor blade.

[0006] Thanks to the use of resistive elements and weldable thermoplastic and / or weldable thermosetting resins, rotor blade modules can be joined together very quickly without the need for epoxy curing. Rotor blades can be divided or segmented into rotor blade modules and assembled on the construction side. This improves the transportability of the rotor blades, as rotor blade modules are easier to transport than whole rotor blades. The inclined shape of the inclined interface section provides an increased surface area for connecting rotor blade modules at the inclined interface section.

[0007] Compared to structural adhesive joints, the cycle time of the method explained above will be an order of magnitude lower than that of standard bonding processes. The process of bonding rotor blade modules can be completed entirely within seconds. Preferably, no additional material is added at any point in the process. The resulting rotor blades will be recyclable, just like the matrix material used for the rotor blade modules. In the case of thermoplastic resins, this may mean 100% resin recycling.

[0008] The mechanical properties of the joints are also improved because the gaps between rotor blade modules can be reduced, as there is no need to fill with foreign paste-like material, and the resulting laminate will be a homogeneous structure. The ability to create microstructurally continuous laminates in a very short cycle time enables modular blade design. This avoids the use of current full-size molds, which could potentially compromise the current design and manufacturing of rotor blades.

[0009] This method is a welding method for welding rotor blade modules together. Therefore, this method can be referred to as a welding method. Steps a) through e) can be performed sequentially or at least partially simultaneously. The rotor blade is segmented. In this context, "segmented" means that the rotor blade can be divided into rotor blade modules along its longitudinal direction, and these rotor blade modules can be joined together by means of a construction-side method to form the rotor blade. In this context, "rotor blade module" means that the rotor blade comprises multiple modules, sub-modules, or components that together form the rotor blade.

[0010] After the rotor blade modules are joined in step e), the rotor blade modules are arranged side-by-side in the longitudinal direction. The number of rotor blade modules is arbitrary. Preferably, at least two rotor blade modules are provided. The rotor blades extend longitudinally from the blade root to the blade tip. A rotor blade module may include a main rotor blade module and a tip rotor blade module, the main rotor blade module including the blade root and the tip rotor blade module including the blade tip. The tip rotor blade module may be referred to as the first rotor blade module. The main rotor blade module may be referred to as the second rotor blade module. Each rotor blade module may have a length of several meters. Providing rotor blade modules may include manufacturing rotor blade modules.

[0011] The rotor blade module may be made of fiber-reinforced plastic or resin material. Preferably, the rotor blade module is made of glass fiber reinforced material. The glass fiber reinforced material includes a matrix or matrix material and glass fibers embedded in the matrix material. The matrix material may be the same as the weldable thermoplastic resin and / or weldable thermosetting resin used for the interface section. Therefore, the weldable thermoplastic resin and / or weldable thermosetting resin may be referred to as the matrix or matrix material, and vice versa.

[0012] In this context, "weldable" means that thermoplastic and / or thermosetting resins can be melted or at least softened by the application of heat. Thermoplastic resins, or thermosetting resins, are plastic polymer materials that become flexible or malleable at certain high temperatures and solidify upon cooling. Thermosetting polymers, resins, or plastics, commonly referred to as thermosetting materials, are polymers that irreversibly harden from soft solid or viscous liquid prepolymers or resins through curing. In contrast, weldable thermosetting resins are materials that can at least be softened by the application of heat, making them suitable for welding inclined joint sections together.

[0013] The rotor blade and rotor blade module can be made of a first half-shell and a second half-shell, which are connected at the leading and trailing edges to form the outer blade shell of the rotor blade or rotor blade module. This outer blade shell surrounds the internal space of the rotor blade or blade module. Reinforcement members or other structural elements can be arranged within this internal space. The outer blade shell or half-shell has an inner surface facing the internal space and an outer surface facing away from the internal space. These surfaces can be referred to as the surfaces of the rotor blade itself.

[0014] In this context, an "inclined" interface segment means that the interface segment is inclined at a certain angle toward one of the aforementioned inner or outer surfaces of the rotor blade. The inclined shape of the interface segment can be produced by forming layers of fabric material arranged in a stepped shape, i.e., arranged on top of each other and offset from each other.

[0015] In this context, "resistive element" means an element that conducts electricity and can generate heat by means of the Joule effect. This heat is generated by the current applied to the resistive element. A power source can be used to power the resistive element. This power source can be a battery, generator, etc. In this context, "powering" a resistive element means applying current to the resistive element. The resistive element may have connection points for electrically connecting the power source to the resistive element. "Providing" a resistive element may include manufacturing the resistive element.

[0016] "Clamping" a resistor between the beveled interface segments means that the resistor is arranged as an external part between the beveled interface segments that need to be joined together. Alternatively, the resistor may be part of at least one of the beveled interface segments. The beveled interface segments "facing" each other includes the beveled interface segments abutting or resting against each other. However, abutting or resting against each other does not preclude placing the resistor between the beveled interface segments that need to be connected.

[0017] In step e), a joint between the inclined interface segments is created by cooling the melted or softened weldable thermoplastic resin and / or weldable thermosetting resin to form the rotor blade. In the case of a weldable thermoplastic resin, the resin is cured or frozen by cooling to form the joint. In the case of a weldable thermosetting resin, the resin undergoes a chemical reaction and / or cures to form the joint.

[0018] According to one embodiment, the resistive element is embedded in at least one of the inclined interface sections.

[0019] This may mean that the resistive element is part of at least one of the beveled interface segments. Alternatively, all beveled interface segments may have this type of resistive element. In this context, “embedded” may mean that the resistive element is placed below or on the surface of one or more beveled interface segments. “Embedded” may also mean that the resistive element is at least partially covered or impregnated by one or more beveled interface segments with a weldable thermoplastic resin and / or a weldable thermosetting resin.

[0020] According to another embodiment, the resistive element has the form of a wire or a mesh.

[0021] Resistive elements can be made of metal. For example, resistive elements are made of copper, silver, aluminum, etc. Alternatively, resistive elements can be made of carbon fiber. Resistive elements can also be woven fabrics made of carbon fiber, etc.

[0022] According to another embodiment, during step c), a resin strip comprising a weldable thermoplastic resin and / or a weldable thermosetting resin is placed between the inclined interface segments.

[0023] The resin strip is used to seal gaps between inclined interface sections that require joining or welding. These gaps may be caused by tolerance mismatches. Preferably, the resin strip is not reinforced by reinforcing fibers. The resin strip may include a resistive element. The resistive element may be embedded in the resin strip. The weldable thermoplastic resin and / or weldable thermosetting resin of the resin strip is preferably the same as the weldable thermoplastic resin and / or weldable thermosetting resin used for the rotor blade module or inclined interface section.

[0024] According to another embodiment, pressure is applied to the inclined interface section during steps d) and / or e).

[0025] The pressure presses the angled interface sections together, causing the molten or softened weldable thermoplastic resin and / or weldable thermosetting resin of the interface sections to form a joint between the angled interface sections.

[0026] According to another embodiment, the pressure is applied by means of a mold covering the joint.

[0027] Specifically, the pressure is applied using a clamping system integrated into the mold. This clamping system includes clamps located at the lower and upper mold housings. Additionally, pneumatic or hydraulic cylinders can be provided to apply pressure to the mold housings using the clamps. In cases where more than one joint is produced, a mold arrangement structure comprising multiple molds can be used. These molds are then placed at a distance from each other in the longitudinal direction to cover the joint.

[0028] According to another embodiment, the first joint is formed during step e), wherein the first joint extends perpendicular to the longitudinal direction, and wherein the first joint extends around the periphery of the outer blade housing of the rotor blade.

[0029] The first joint is a miter joint. Therefore, the first joint can also be referred to as the first miter joint. The first joint is circumferentially closed. This means that the first joint extends around the entire periphery or boundary of the outer blade housing. The first joint is created by connecting first inclined interface sections together. The first inclined interface sections are located at the ends of the rotor blade module that need to be connected. The first inclined interface sections are perpendicular to the longitudinal direction and extend around the periphery of the outer blade housing. The first inclined interface sections preferably include a continuous, particularly strip-shaped geometry. In this context, "continuous" means that the first inclined interface sections are not interrupted. The first inclined interface sections preferably extend around the entire periphery or boundary of the rotor blade, the corresponding rotor blade module, or the outer blade housing.

[0030] According to another embodiment, the second joint is formed during step e), wherein the second joint extends parallel to the longitudinal direction, and wherein the second joint extends along the spar cap of the rotor blade.

[0031] Preferably, more than one spar cap is provided. Preferably, the spar cap has a second inclined interface section extending in the longitudinal direction. Therefore, the first inclined interface section and the second inclined interface section are arranged perpendicular to each other.

[0032] According to another embodiment, a first connector is formed between first inclined interface sections of the rotor blade module, wherein a second connector is formed between second inclined interface sections of the rotor blade module, and wherein the first inclined interface section is steeper than the second inclined interface section.

[0033] In this context, "steeper" means that the tilt angle of the first tilted interface section is greater than that of the second tilted interface section.

[0034] According to another embodiment, the first inclined interface segment has a thickness / length ratio of 1 / 8, wherein the second inclined interface segment has a thickness / length ratio of 1 / 100.

[0035] A thickness-to-length ratio of 1 / 8 for the first inclined interface section means that the thickness of the first inclined interface section decreases by 1 mm along its 8 mm length. The same applies to the second inclined interface section.

[0036] According to another embodiment, a transverse reinforcement extending perpendicular to the longitudinal direction is provided to support the inclined interface section from the internal space of the rotor blade.

[0037] Specifically, the lateral stiffener supports the first inclined interface section. When pressure is applied from the outside using a mold, the lateral stiffener generates a counter-pressure from its internal space. Therefore, the first inclined interface sections are pressed together evenly. The lateral stiffener supports one of the first inclined interface sections of the rotor blade modules that need to be connected. The lateral stiffener can be inserted into the corresponding rotor blade module during step a) or c).

[0038] According to another embodiment, a longitudinal reinforcement extending parallel to the longitudinal direction is provided to support the inclined interface section from the internal space of the rotor blade.

[0039] The longitudinal stiffener may have an I-shape or a double T-shape. Specifically, the longitudinal stiffener supports the second inclined interface section. When pressure is applied from the outside using a mold, the longitudinal stiffener generates a counter-pressure from its internal space. Therefore, the second inclined interface sections are pressed together uniformly. The longitudinal stiffener may be inserted into the corresponding rotor blade module during step a) or c).

[0040] According to another embodiment, the transverse stiffener and the longitudinal stiffener together form a pre-assembled joining component, which is inserted into the rotor blade module during step a) or c).

[0041] The rotor blade modules and connecting components can be transported to the construction site as separate parts.

[0042] According to another embodiment, the resistive element is covered by an insulating material, wherein the insulating material comprises a weldable thermoplastic resin and / or a weldable thermosetting resin.

[0043] The insulating material prevents electric arcing when powering the resistive element. The weldable thermoplastic resin and / or weldable thermosetting resin of the insulating material are preferably the same as the material used for the inclined interface section.

[0044] According to another embodiment, the resistive element remains in the rotor blade after step e).

[0045] This means that the resistive element is an integral part of the rotor blade. Therefore, the resistive element is not removed from the rotor blade after the rotor blade modules are joined together. The resistive element can be used as a reinforcing material.

[0046] Other possible embodiments or alternatives to the invention also encompass combinations of features not explicitly mentioned herein, as described above or below with reference to embodiments. Those skilled in the art can also add individual or isolated aspects and features to the most basic form of the invention. Attached Figure Description

[0047] 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: Figure 1 A schematic perspective view of a wind turbine according to one embodiment is shown; Figure 2 A schematic perspective view of a rotor blade according to one embodiment is shown; Figure 3 It shows according to Figure 2 A schematic exploded view of the rotor blades; Figure 4 It shows along Figure 2 A schematic cross-sectional view of the rotor blades along the intersection line IV-IV; Figure 5 A schematic perspective view of a rotor blade module according to one embodiment is shown; Figure 6 It shows according to Figure 2 A schematic cross-sectional view of the rotor blades; Figure 7 It shows according to Figure 2 Another schematic cross-sectional view of the rotor blades; Figure 8 A schematic perspective view of a lateral stiffener according to one embodiment is shown; Figure 9 It shows according to Figure 5 Another schematic perspective view of the rotor blade module; Figure 10 It shows according to Figure 2 Another schematic cross-sectional view of the rotor blades; Figure 11 It shows according to Figure 2 Another schematic perspective view of the rotor blades; Figure 12A schematic cross-sectional view of a mold according to one embodiment is shown; Figure 13 It shows according to Figure 12 Another schematic cross-sectional view of the mold; Figure 14 A schematic cross-sectional view of a rotor blade according to another embodiment is shown; Figure 15 A cross-sectional view of a mold according to another embodiment is shown; Figure 16 It shows according to Figure 15 Another cross-sectional view of the mold; Figure 17 It shows according to Figure 2 Another schematic cross-sectional view of the rotor blades; Figure 18 It shows according to Figure 2 Another schematic cross-sectional view of the rotor blades; Figure 19 A schematic exploded view of a rotor blade according to another embodiment is shown; Figure 20 It shows according to Figure 19 Another schematic exploded view of the rotor blades; Figure 21 A schematic perspective view of a mold arrangement structure according to one embodiment is shown; Figure 22 It shows according to Figure 21 A schematic cross-sectional view of the mold arrangement structure; Figure 23 A schematic perspective view of a joining member according to one embodiment is shown; and Figure 24 The following diagram shows the assembly method based on... Figure 2 A flowchart of an embodiment of a method for rotor blades.

[0048] In the accompanying drawings, unless otherwise indicated, the same reference numerals denote the same or functionally equivalent elements. Detailed Implementation

[0049] Figure 1 A wind turbine 1 according to one embodiment is shown.

[0050] "Wind turbine" currently refers to a device that converts the kinetic energy of wind into rotational energy, which can then be converted back into electrical energy.

[0051] The wind turbine 1 includes a rotor 2, which is connected to a generator (not shown) arranged in a nacelle 3. The nacelle 3 is located at the upper end of the tower 4 of the wind turbine 1.

[0052] The rotor 2 comprises three rotor blades 5. The rotor blades 5 are connected to the hub 6 of the wind turbine 1. This type of rotor 2 can have a diameter ranging from, for example, 30 meters to 160 meters or even larger. The rotor blades 5 are subjected to high wind loads. At the same time, the rotor blades 5 need to be lightweight. For these reasons, the rotor blades 5 in modern wind turbines 1 are made of fiber-reinforced composite materials. Glass fiber in the form of a unidirectional fiber mat is often used.

[0053] Figure 2 A rotor blade 5 according to one embodiment is shown.

[0054] The rotor blade 5 includes: an aerodynamically designed portion 7 shaped to optimally utilize wind energy; and a blade root 8 for connecting the rotor blade 5 to the hub 6. The rotor blade 5 includes a longitudinal direction L. This longitudinal direction L points from the blade root 8 towards the aerodynamically designed portion 7. However, this longitudinal direction L can also be oriented in the opposite direction.

[0055] These rotor blades 5 are hollow composite structures designed to be as lightweight and rigid as possible to maximize the transfer of mechanical energy from wind to the generator. The most commonly used material for manufacturing this hollow structure is a composite material in which reinforcing fibers are embedded in a polymer matrix.

[0056] Figure 3 An exploded perspective view of rotor blade 5 is shown.

[0057] To date, the choice of hollow structures for joining, bonding, or welding rotor blades 5 has been limited to creating the entire structure in a one-off molding process that is technically complex and requires specialized tooling, or joining sub-components by means of adhesive bonding processes that also use thermosetting materials, most commonly blade half-shells 9, 10.

[0058] The first half-shell 9 and the second half-shell 10 of the rotor blade 5 are manufactured and cured in parallel. The two half-shells 9 and 10 are then joined together using the adhesive bonding process, along with additional structural elements 11 and 12, such as shear webs. The half-shells 9 and 10 may have integrated spar caps 13 and 14. Figure 4 More generally, the half-shells 9 and 10, structural elements 11 and 12, and spar caps 13 and 14 can be referred to as “components” of the rotor blades 5.

[0059] Figure 4 It shows according to Figure 2 A cross-sectional view of rotor blade 5 along the intersecting line IV-IV.

[0060] The rotor blade 5 has an outer blade housing 15, which includes a first half-housing 9 and a second half-housing 10 connected to each other at the leading edge 16 of the rotor blade 5. The half-housings 9 and 10 are also connected to each other at the trailing edge 17 of the rotor blade 5. The outer blade housing 15 may comprise a composite fiber material, particularly a glass fiber mat. The fiber material is impregnated with a polymer material, particularly a thermoplastic or weldable thermosetting resin. The first half-housing 9 constitutes the pressure side of the rotor blade 5. The second half-housing 10 constitutes the suction side of the rotor blade 5.

[0061] The first half-shell 9 includes an inner surface 18, and the second half-shell 10 includes an inner surface 19, the inner surfaces being arranged opposite to and facing each other. The internal space 20 of the rotor blade 5 is defined by the inner surfaces 18 and 19. The first half-shell 9 includes an outer surface 21 facing away from the inner surface 18. The second half-shell 10 includes an outer surface 22 facing away from the inner surface 19. Structural elements 11 and 12 are located within the internal space 20, extending from the inner surface 18 of the first half-shell 9 to the inner surface 19 of the second half-shell 10.

[0062] Structural elements 11, 12 and spar caps 13, 14 extend in the longitudinal direction L. Structural elements 11, 12 and spar caps 13, 14 preferably comprise fiber composite materials, particularly glass fiber mats. Structural elements 11, 12 are shear webs.

[0063] Figure 5 A schematic perspective view of one embodiment of rotor blade module 23 of rotor blade 5 is shown.

[0064] Rotor blade module 23 may be referred to as the first rotor blade module. To enhance the transportability of the rotor blade 5, it is segmented or separated into multiple rotor blade modules 23, which can be connected together to form the rotor blade 5. In particular, Figure 5 The blade tip or rotor blade tip module is shown. The rotor blade module 23 has an interface section 24 that is inclined and extends around the entire perimeter or circumference of the rotor blade module 23.

[0065] Interface segment 24 may be referred to as an inclined interface segment. The inclined shape of interface segment 24 can be achieved by forming layers of fabric material arranged in a stepped shape, i.e., arranged on top of each other and offset from each other. With the aid of interface segment 24, rotor blade module 23 can be joined to another rotor blade module. Figure 5 (Not shown in the image).

[0066] Interface segment 24 includes a weldable resin as the matrix of the composite material in interface segment 24. In this context, "weldable" means that the matrix can be melted or at least softened to join interface segment 24 to another rotor blade module. The matrix can be a thermoplastic material as well as a rigid plastic material. The matrix can be used for the entire rotor blade 5 or only for interface segment 24. In the latter case, the remainder of rotor blade 5 can be manufactured as a standard blade.

[0067] Figure 6 and Figure 7 Both show a cross-sectional view of the rotor blade 5 cut perpendicular to the interface segment 24. Figure 7 Detailed views are also shown. These will be referenced in the following text. Figure 6 and Figure 7 .

[0068] In addition to the rotor blade module 23, of which only the second half-shell 10 is shown, the rotor blade 5 also includes another rotor blade module 25. The number of rotor blade modules 23 and 25 is arbitrary. However, there are at least two rotor blade modules 23 and 25. The rotor blade module 25 may be referred to as the rotor blade main module or the rotor blade body. The rotor blade module 25 may include a blade root 8. The rotor blade module 25 may also be referred to as the second rotor blade module.

[0069] Rotor blade module 25 has an interface section 26, which corresponds to the interface section 24 of rotor blade module 23. In other words, interface section 26 is also inclined. Therefore, interface section 26 can be referred to as an inclined interface section. Interface sections 24 and 26 can be referred to as first interface sections. In this context, "inclined" means that interface section 24 is inclined towards the inner surface 19 at an angle α. Therefore, interface section 26 is inclined towards the outer surface 22 at an angle β.

[0070] The rotor blade 5 can be assembled by engaging the rotor blade modules 23 and 25 at interface sections 24 and 26. This can be accomplished by inserting the interface section 24 of the rotor blade module 23 into the corresponding interface section 26 of the rotor blade module 25, as follows: Figure 6 As shown in the diagram. The process is carried out without any pressure being applied. Preferably, it is accomplished using a simple means of transport.

[0071] Resistive element 27 is placed between interface sections 24 and 26. In this context, "resistive element" means that resistive element 27 has resistance and can therefore be heated by applying current to it. Resistive element 27 is a mesh or includes a mesh. For example, resistive element 27 may be made of a metal such as copper or any other conductive material such as carbon fiber. Resistive element 27 may be made of carbon braided fabric.

[0072] Resistor 27 can be placed as an additional component between interface segments 24 and 26. However, resistor 27 can also be integrated into at least one of interface segments 24 and 26. In this case, resistor 27 is embedded in the base of at least one of interface segments 24 and 26. However, both interface segments 24 and 26 may have resistor 27. Alternatively, another resistor 27 can be placed as an additional component between interface segments 24 and 26.

[0073] Both rotor blade modules 23, 25 and / or both interface sections 24, 26 include reinforcing fibers F embedded in a weldable thermoplastic resin and / or a weldable thermosetting resin M. The weldable thermoplastic resin and / or weldable thermosetting resin M may be referred to as the matrix or matrix material. In other words, the term "thermoplastic resin and / or weldable thermosetting resin" may be replaced by the terms "matrix" or "matrix material," and vice versa.

[0074] Then, the resistive element 27 is powered. This is accomplished by applying a current to the resistive element 27. This current heats the resistive element 27 by means of the Joule effect. The resistive element 27 is heated, and heat H is applied to the two interface sections 24, 26. Due to this heat H, the substrate of the interface sections 24, 26 is heated to a point of partial melting or at least softening.

[0075] To create a joint 28 between interface sections 24, 26 or rotor blade modules 23, 25 Figure 7 A pressure p is applied to both sides of rotor blade modules 23, 25. For example, a pressure p of 2 to 5 bar can be applied. Joint 28 may be referred to as the first joint. Pressure p is also required to prevent undesirable deformation in the area of ​​joint 28.

[0076] Pressure p can be applied using a mold (not shown) or the like. The current stops, and pressure p is removed, thus creating a uniform laminate in joint 28. Resistive element 27 is not removed from joint 28. Resistive element 27 remains within joint 28. Joint 28 is a squash joint, and therefore may be referred to as a squash joint.

[0077] Given that the rotor blade 5 is formed by a closed outer blade housing 15, it is impossible to apply peripheral pressure p from the internal space 20 of the rotor blade 5 once the rotor blade modules 23, 25 to be joined are placed together for the final welding as explained above.

[0078] Figure 8 A schematic perspective view of one embodiment of the lateral stiffener 29 is shown. Figure 9 A schematic perspective view of the rotor blade module 23, including the lateral stiffener 29, is shown. Reference will also be made to the following text. Figure 8 and Figure 9 .

[0079] The transverse stiffener 29 may be made of glass fiber reinforced plastic or the like. The transverse stiffener 29 includes a strip-shaped flange 30 and a plate-shaped web 31. The flange 30 extends circumferentially around the web 31. The transverse stiffener 29 is placed within the rotor blade module 23, particularly within the interface section 24. The transverse stiffener 29 has a negative shape representing the section where the rotor blades 5 are separated and need to be joined.

[0080] The placement of the lateral stiffener 29 within the rotor blade module 23 is preferably completed during the manufacturing stage of the rotor blade module 23. The lateral stiffener 29 can be positioned precisely using a positioning fixture. Ideally, the lateral stiffener 29 is welded to the interface section 24 of the rotor blade module 23 with its flange 30. However, the lateral stiffener 29 can also be placed within the rotor blade module 23 on-site or at the construction site of the wind turbine 1. This can be accomplished using room-temperature curing adhesives or resins.

[0081] Figure 10 A cross-sectional view of rotor blade 5 is shown.

[0082] As from Figure 10 As can be seen, the transverse stiffener 29 has a T-shaped profile. The flange 30 has at least the width of the interface segments 24, 26 or the joint 28 to fully support the interface segments 24, 26. The web 31 of the transverse stiffener 29 may include a sandwich laminate designed to withstand the compressive pressure p during the welding process as explained above. Figure 6 The transverse stiffener 29 can be used to weld the joint 28 during the blade's service life, thereby providing a reduction in the continuous operating load on the joint 28.

[0083] Figure 11 A schematic partial perspective view of a rotor blade 5 having a mold 32 for applying pressure p to a connector 28 is shown. Figure 12 and Figure 13 Both show cross-sectional views of mold 32. Reference will be made to both in the following text. Figures 11 to 13 .

[0084] During the final assembly of rotor blade 5, for example at the construction site of wind turbine 1, rotor blade module 23, including lateral stiffener 29, is placed within rotor blade module 25 such that inclined interface sections 24, 26 mate with each other. This can be performed using a transport vehicle or a crane system employing slings.

[0085] Resistive element 27 or more (not shown) are embedded or placed in interface segments 24, 26. The resistive element 27 is at least partially exposed and connected in order to apply current. In this context, "exposed" means that the substrate is partially removed from the resistive element 27 to electrically connect it to a power source.

[0086] Mold 32 is a support component or may be referred to as a support component.

[0087] The mold 32 has a base support or a lower mold housing 33 for supporting the first half-shell 9 facing the floor. The lower mold housing 33 is used to support the rotor blades 5 in the region of the joint 28. The lower mold housing 33 has a negative shape relative to the first half-shell 9 facing the floor. The lower mold housing 33 is configured to withstand pressure p and avoid damage to the blade laminate. The lower mold housing 33 has a cavity 35, which is a negative shape relative to the first half-shell 9. The cavity 35 may have a composite surface or any other material capable of withstanding pressure p and avoiding damage to the joint 28.

[0088] The mold 32 also includes a top support or an upper mold housing 34. The upper mold housing 34 has a cavity 36, which is the negative shape of the second half-shell 10. The upper mold housing 34 has the shape of the outline of the connector 28. After the rotor blade modules 23, 25 are placed on the lower mold housing 33, the upper mold housing 34 is placed on the lower mold housing 33, thereby clamping the rotor blade modules 23, 25 between the mold housings 33, 34.

[0089] Cavity 36 may also have a composite surface or any other material capable of withstanding pressure p and avoiding damage to connector 28. The upper mold housing 34 can then be clamped to the lower mold housing 33 by means of clamps 37 to 40. The lower mold housing 33 has two clamps 37, 38. The upper mold housing 34 also has two clamps 39, 40. For example, hydraulic cylinders 41, 42 can be used to compress the clamps 37 to 40. One hydraulic cylinder 41, 42 may be present. Two hydraulic cylinders 41, 42 may also be present. The hydraulic cylinders 41, 42 will transmit the required pressure p to the periphery of connector 28.

[0090] Hydraulic cylinders 41 and 42 are then powered, and a target pressure p is applied to the entire area of ​​the joint 28 to be welded. The internal transverse reinforcement 29 will respond to the applied pressure p, thereby generating the required counter-pressure or internal pressure p to achieve a dimensionally stable joint 28. Due to the reaction force induced by the internal transverse reinforcement 29, the required peripheral pressure p, normal to the surface at each point, is generated throughout the weld line. The resistive element 27 is then connected and current is passed through it, thereby performing a thermoplastic welding process by applying heat H to the interface sections 24 and 26 (not shown).

[0091] Once cooled, the resulting joint 28 is a miter joint, in which the laminate comprises a single substrate and the rotor blade 5 is a single, ready-to-use assembly. The transverse reinforcement 29 is retained as a structural element within the rotor blade 5. The exposed joint lines of joint 28 can be covered with the laminate to prevent the ingress of fluids or unwanted substances and / or sealed and coated.

[0092] Figure 14 A cross-sectional view of another embodiment of rotor blade 5 is shown.

[0093] In a further improvement to rotor blade 5, structural elements 11 and 12, particularly the shear web, are provided with openings 43 and 44 on the corresponding sides of the joint 28. The openings 43 and 44 may be circular in shape. However, the openings 43 and 44 may have any desired shape. This allows the shear load at the location of the joint 28 to pass through the transverse stiffener 29, thus ensuring the structural integrity of rotor blade 5.

[0094] Figure 15 and Figure 16 Both show cross-sectional views of another embodiment of mold 32 as explained above. Reference will be made to both in the following text. Figure 15 and Figure 16 .

[0095] In this embodiment, mold 32 has only the lower mold housing 33 as explained above. Pressure p is applied to the second half-housing 10 by means of hydraulic cylinders 45 to 47, etc. The number of hydraulic cylinders 45 to 47 is arbitrary. Three hydraulic cylinders 45 to 47 may be provided. Each hydraulic cylinder 45 to 47 has a pad 48 to 50, which is shaped to match the contour of the second half-housing 10. The pads 48 to 50 distribute the pressure p evenly. The pads 48 to 50 may have a rectangular, circular, elliptical, or any desired shape.

[0096] Hydraulic cylinders 45 to 47 can be mounted to a movable and fixed frame (not shown). The number and position of hydraulic cylinders 45 to 47 are selected to generate sufficient and uniform pressure p in the welding area.

[0097] like Figure 16 As shown, hydraulic cylinders 45 to 47 descend, and a target pressure p is applied to the entire area of ​​the joint 28 (not shown) to be welded. Due to the reaction force caused by the opposing transverse reinforcement 29, the desired peripheral pressure p, normal to the surface at each point, is generated along the entire weld line. A resistive element 27 (not shown) is then connected and current is passed through it, thereby performing a thermoplastic welding process by applying heat H to the interface segments 24, 26, or joint 28.

[0098] Figure 17 and Figure 18Both show additional sectional views of the rotor blade 5 cut perpendicular to the interface sections 24 and 26. Reference will be made to both views below. Figure 17 and Figure 18 .

[0099] Depending on the type of materials and processes used in manufacturing the rotor blades 5, some tolerance mismatch may occur between the rotor blade modules 23 and 25 at the inclined interface sections 24 and 26. To address this issue, a resin strip 51 comprising a weldable thermoplastic resin and / or a weldable thermosetting resin M, as mentioned above, can be used at the inclined interface sections 24 and 26 to fill the gap 52 created between the interface sections 24 and 26 due to any possible mismatch. The resin strip 51 may include a resistive element 27 (not shown), as explained above.

[0100] Under pressure p and heat H provided by resistive element 27, the material of resin strip 51 will melt, resulting in a uniform and continuous joint 28. Preferably, resin strip 51 is not fiber reinforced. However, resin strip 51 may also be fiber reinforced.

[0101] Figure 19 An exploded perspective view of rotor blade 5 according to another embodiment is shown. Figure 20 Another exploded perspective view of rotor blade 5 is shown. Reference will be made simultaneously below. Figure 19 and Figure 20 .

[0102] Considering the previous reference Figure 3 and Figure 4 The structural design of the rotor blade 5 explained may require that if the joint 28 is located further away from the tip of the rotor blade 5, the load-bearing spar caps 13 and 14 in the joint 28 have a longer and less pronounced slope, since the load introduction at the joint 28 should be smoother.

[0103] Segmenting and joining rotor blades 5 at the center portion can bring greater benefits in terms of cost, transportation, and field logistics. The aforementioned method allows segmented rotor blades 5 to be joined at any location.

[0104] Each spar cap 13, 14 of rotor blade module 23 has an inclined interface section 53 at its end. Rotor blade module 25 has a corresponding interface section 54. Interface sections 53, 54 together form a joint 55 extending in the longitudinal direction L. Joint 55 is also an inclined joint. Interface sections 53, 54 may be referred to as second interface sections. Joint 55 may be referred to as a second joint. Interface sections 53, 54 may also be referred to as inclined interface sections.

[0105] Compared to interface segments 24 and 26, interface segments 53 and 54 are less steep. For example, interface segments 24 and 26 may have a steep transition ratio of 1:8 or 1 / 8, while interface segments 53 and 54 may have a smooth transition ratio of 1:100 or 1 / 100. In this context, "ratio" refers to the ratio between the thickness and length of the corresponding interface segments 24, 26, 53, and 54.

[0106] The ends of the spar caps 13, 14, including the interface section 53, are supported by additional longitudinal stiffeners 56 or shear webs. The longitudinal stiffener 56 may have openings 57, 58 at its beginning and / or its end. This longitudinal stiffener 56 acts as a welding support for the interface sections 53, 54 of the spar caps 13, 14, for applying welding pressure p in the same manner as the transverse stiffener 29. Like the interface sections 24, 26, the interface sections 53, 54 comprise thermoplastic resin and / or weldable thermosetting resin M.

[0107] In the case of impregnated dry fabrics, the inclined shape of the interface sections 53 and 54 can be achieved by means of a ply-drop construction. In the case of solid parts such as pultruded parts, they can also be processed using unidirectional glass or carbon fiber. For example, the remaining parts of the glass laminate at the half-shells 9 and 10 are inclined using a more aggressive ratio of 1:8.

[0108] Inclined spar caps 13 and 14 with interface sections 53 protrude from rotor blade modules 23 or 25. Corresponding opposite interface sections 54 are constructed in the ends of spar caps 13 and 14 at another rotor blade module 25.

[0109] Then, the inclined spar caps 13 and 14 and the longitudinal reinforcement 56 are inserted into the rotor blade module 25, as by means of... Figure 19 As indicated by arrow 59. Joints 28 and 55 are formed at the stacked areas of the half-shells 9 and 10 at steep, sloping interface sections 24 and 26 and at smooth, sloping interface sections 53 and 54.

[0110] The surfaces of the interface segments 24, 26, 53, and 54 can be prepared just before the spar caps 13 and 14 and the longitudinal reinforcement 56 are inserted into the rotor blade module 25 for corresponding welding processes, which may include resistance welding, induction welding, and / or chemical welding.

[0111] exist Figure 20Rotor blade module 25 is not shown. Resistor element 27, as explained above, is placed on or embedded in interface section 53. Resistor element 27 has two connection points 60, 61. Connection points 60, 61 are electrically connected to the two poles 62, 63 of power supply 64. Resistor element 27 is positioned on the welded surfaces of spar caps 13, 14, i.e., on the top of interface section 53, thereby exposing both connection points 60, 61 at the location of connector 28 for easy electrical connection to power supply 64.

[0112] Insulating material 65 is placed between the wires of resistive element 27 or on top of resistive element 27 to prevent arcing. Insulating material 65 can be the solderable resin itself. Insulating material 65 may include solderable thermoplastic resins and / or solderable thermosetting resins M as mentioned above. Resistive element 27 may be embedded in insulating material 65. Resistance welding process may be performed as described above.

[0113] Once the two rotor blade modules 23, 25 of the segmented rotor blade 5 are connected, joints 28, 55 in the form of continuous oblique joints are established at both the periphery of the outer blade housing 15 and the length of the spar caps 13, 14. Reinforcements 29, 56 located below each joint 28, 55 in the transverse and longitudinal directions L will serve as supports for the application of welding loads in the two joints 28, 55.

[0114] Figure 21 A schematic perspective view of one embodiment of the mold arrangement structure 66 for connecting rotor blade modules 23, 25 is shown. Figure 22 A cross-sectional view of the mold arrangement structure 66 is shown. Reference will also be made to the following text. Figure 21 and Figure 22 .

[0115] The mold arrangement structure 66 includes a plurality of molds 32 as explained above. The molds 32 are arranged at a distance from each other along the longitudinal direction L. The molds 32 cover the lengths of the joints 28 and 55. The mold arrangement structure 66 may include a longitudinal extension 67 to evenly distribute the pressure p on the top of the spar cap 13.

[0116] The welding of interface sections 24, 26 and interface sections 53, 54 at spar caps 13, 14 both occur at the same process stage. Once welded, a continuous laminate is then formed in the two joints 28, 55. The transverse stiffener 29 and longitudinal stiffener 56 are then retained in the rotor blades 5, thus serving as shear webs and full-function structural elements.

[0117] Figure 23 A schematic perspective view of one embodiment of the joining member 68 is shown.

[0118] The joining component 68 is pre-assembled and includes inclined spar caps 13 and 14 having interface segments 53 (not shown) as previously explained, two longitudinal reinforcements 56, and a transverse reinforcement 29, which is sandwiched between the longitudinal reinforcements 56 when viewed along the longitudinal direction L.

[0119] The joining component 68 is designed to join rotor blade modules 23, 25 together. The rotor blade modules 23, 25 and the joining component 68 are transported separately. The joining component 68 is then inserted into the two rotor blade modules 23, 25 and joined by resistance welding as explained above.

[0120] Figure 24 A flowchart of one embodiment of a method for assembling rotor blade 5 is shown.

[0121] In step S1, at least two different rotor blade modules 23, 25 are provided, which segment the rotor blade 5 along the longitudinal direction L of the rotor blade 5. Step S1 may include manufacturing rotor blade modules 23, 25. The number of rotor blade modules 23, 25 is arbitrary. As mentioned earlier, each rotor blade module 23, 25 has interface segments 24, 26, 53, 54, wherein the interface segments 24, 26, 53, 54 comprise a weldable thermoplastic resin and / or a weldable thermosetting resin M. The weldable thermoplastic resin and / or the weldable thermosetting resin M may be referred to as a matrix or matrix material. The interface segments 24, 26, 53, 54 are inclined or sloped.

[0122] In step S2, a resistive element 27 is provided. Step S2 may include manufacturing the resistive element 27. Step S2 may also include embedding one or more resistive elements 27 into one or more of the interface segments 24, 26, 53, and 54.

[0123] In step S3, the rotor blade modules 23, 25 and the resistor element 27 or multiple resistor elements 27 are arranged such that the interface sections 24, 26, 53, 54 face each other or abut against each other, and the resistor element 27 is sandwiched between the interface sections 24, 26, 53, 54. In step S3, a resin strip 51 comprising a weldable thermoplastic resin and / or a weldable thermosetting resin M may be placed between the interface sections 24, 26, 53, 54.

[0124] In step S4, the resistive element 27 is powered to apply heat H to the weldable thermoplastic resin and / or weldable thermosetting resin M to melt or soften it. This can be accomplished by connecting the resistive element 27 to the power supply 64.

[0125] In step S5, the interface segments 24, 26, 53, and 54 are joined together at joints 28 and 55 by means of molten or softened weldable thermoplastic resin and / or weldable thermosetting resin M to form rotor blades 5.

[0126] Steps S1 to S5 may be performed sequentially or at least partially simultaneously. During steps S4 and / or S5, pressure p is applied to interface sections 24, 26, 53, and 54. Pressure p may be applied by means of the mold 32 and / or mold arrangement structure 66 covering the joints 28 and 55.

[0127] Although the invention has been described with reference to preferred embodiments, it will be apparent to those skilled in the art that modifications are possible in all embodiments.

Claims

1. A method for assembling rotor blades (5) of a wind turbine (1), the method comprising the following steps: a) Provide (S1) at least two different rotor blade modules (23, 25) that segment the rotor blade (5) along the longitudinal direction (L) of the rotor blade (5), wherein each rotor blade module (23, 25) has an inclined interface segment (24, 26, 53, 54), and wherein the inclined interface segment (24, 26, 53, 54) comprises a weldable thermoplastic resin and / or a weldable thermosetting resin (M). b) Provide (S2) resistor element (27). c) The rotor blade modules (23, 25) and the resistive element (27) are arranged (S3) such that the inclined interface sections (24, 26, 53, 54) face each other, and the resistive element (27) is sandwiched between the inclined interface sections (24, 26, 53, 54). d) Powering the resistive element (27) (S4) to apply heat (H) to the weldable thermoplastic resin and / or the weldable thermosetting resin (M) to melt or soften them, and e) The inclined interface segments (24, 26, 53, 54) are joined together (S5) at the joints (28, 55) by means of a melted or softened weldable thermoplastic resin and / or weldable thermosetting resin (M) to form the rotor blade (5). The transverse reinforcement (29) extending perpendicular to the longitudinal direction (L) is provided to support the inclined interface section (24, 26) from the internal space (20) of the rotor blade (5).

2. The method of claim 1, wherein, The resistive element (27) is embedded in at least one of the inclined interface sections (24, 26, 53, 54).

3. The method of claim 1 or 2, wherein, The resistive element (27) has the form of a wire or a mesh.

4. The method according to claim 1 or 2, wherein, During step c), a resin strip (51) comprising a weldable thermoplastic resin and / or a weldable thermosetting resin (M) is placed between the inclined interface sections (24, 26, 53, 54).

5. The method according to claim 1 or 2, wherein, During steps d) and / or e), pressure (p) is applied to the inclined interface sections (24, 26, 53, 54).

6. The method according to claim 5, wherein, The pressure (p) is applied by means of a mold (32) covering the joints (28, 55).

7. The method according to claim 1 or 2, wherein, The first joint (28) is formed during step e), wherein the first joint (28) extends perpendicular to the longitudinal direction (L), and wherein the first joint (28) extends around the periphery of the outer blade housing (15) of the rotor blade (5).

8. The method according to claim 7, wherein, The second joint (55) is formed during step e), wherein the second joint (55) extends parallel to the longitudinal direction (L), and wherein the second joint (55) extends along the spar caps (13, 14) of the rotor blade (5).

9. The method according to claim 8, wherein, The first connector (28) is formed between the first inclined interface sections (24, 26) of the rotor blade modules (23, 25), wherein the second connector (55) is formed between the second inclined interface sections (53, 54) of the rotor blade modules (23, 25), and wherein the first inclined interface section (24, 26) is steeper than the second inclined interface section (53, 54).

10. The method according to claim 9, wherein, The first inclined interface segments (24, 26) have a thickness / length ratio of 1 / 8, and the second inclined interface segments (53, 54) have a thickness / length ratio of 1 / 100.

11. The method according to claim 1, wherein, A longitudinal reinforcement (56) extending parallel to the longitudinal direction (L) is provided to support the inclined interface section (53, 54) from the internal space (20) of the rotor blade (5).

12. The method according to claim 11, wherein, The transverse reinforcement (29) and the longitudinal reinforcement (56) together form a pre-assembled joining component (68), which is inserted into the rotor blade module (23, 25) during step a) or c).

13. The method according to claim 1 or 2, wherein, The resistive element (27) is covered by an insulating material (65), wherein the insulating material (65) comprises a weldable thermoplastic resin and / or a weldable thermosetting resin (M).

14. The method according to claim 1 or 2, wherein, After step e), the resistive element (27) remains in the rotor blade (5).

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