CN115697684A

CN115697684A - Manufacturing a wind turbine blade

Info

Publication number: CN115697684A
Application number: CN202080001019.1A
Authority: CN
Inventors: K·汉拉罕; T·诺布洛克; J·宏特; D·J·刘易斯; K·A·帕萨拉夸
Original assignee: LM Wind Power AS; Blade Dynamics LLLP
Current assignee: LM Wind Power AS; Blade Dynamics LLLP
Priority date: 2020-05-26
Filing date: 2020-05-26
Publication date: 2023-02-03
Also published as: WO2021239218A1

Abstract

The invention provides a method for manufacturing a shell part of a wind turbine blade. The method comprises laying one or more outer skin fibre layers in a wind turbine blade shell part mould; providing a spar cap component comprising one or more pre-cured elongate reinforcing elements, the spar cap component having a first end and a second end; gradually bringing the spar cap components into contact with one or more of the outer skin fibre layers, starting from the first end; laying one or more inner skin fiber layers in contact with the spar cap components; providing a liquid resin into the mould and curing the resin, thereby obtaining the wind turbine blade shell part. The invention also provides a wind turbine blade obtainable by the method.

Description

Manufacturing a wind turbine blade

Technical Field

The present invention relates to the manufacture of wind turbine blades, in particular of the type comprising one or more pre-cured elements.

Background

Wind energy is a clean and environmentally friendly energy source. A wind turbine typically includes a tower, generator, gearbox, nacelle, and one or more rotor blades. Wind turbine blades capture kinetic energy of wind using known foil principles. Modern wind turbines may have rotor blades that exceed 90 meters in length.

Wind turbine blades are typically manufactured by forming two shell parts or shell halves from layers of woven fabric or fibres and resin. Spar caps or primary laminates are placed or integrated in the shell halves and may be combined with shear webs or spars to form structural supports. The spar caps or main laminate may be joined to or integrated within the interior sides of the halves of the shell.

As the blades increase in size, many of the manufacturing steps become more complex. Any errors made by a process in this process take more and more time to correct. One such processing step is to place one or more pre-cured elements on the fibre layers already laid in the blade part mould. The overall length, width and weight of such elements generally increase with the size of the blade. It is therefore desirable to lay these elements correctly for the first time, to avoid having to redo this step.

The present invention provides a method of arranging pre-cured elements in a mould in an efficient and controllable manner.

Disclosure of Invention

In a first aspect, the present invention provides a method for manufacturing a wind turbine blade shell member having a tip end and a root end. The method comprises the following steps:

-laying one or more outer skin fibre layers in a wind turbine blade shell part mould,

-providing a spar cap component comprising one or more pre-cured reinforcing elements, the spar cap component having a first end and a second end,

gradually bringing the spar cap parts into contact with one or more of the outer skin fibre layers starting from the first end,

-laying one or more inner skin fibre plies in contact with the spar cap components,

-providing a liquid resin into the mould and curing the resin, thereby obtaining a wind turbine blade shell part.

When manufacturing a wind turbine blade shell part, a dry fibre layer (such as a fibre mat) is typically first laid in a blade shell part mould. These will constitute the outer skin of the shell parts. After the addition of the fibre layers, one or more pre-curing elements may be added, thereby forming another part of the blade shell component. Using this method advantageously provides a spar cap. The addition of pre-cured elements to the outer skin fibre layers is tedious and the fibre layers often become displaced or wrinkled during the process of adding the pre-cured elements.

Embodiments of the present invention alleviate these problems. The inventors have found that adding the spar cap components starting from one end of the spar cap components and gradually bringing them into contact with the underlying fibre layers increases the accuracy with which the spar cap components are arranged on the fibre layers. Furthermore, the risk of having to lift the spar cap parts again due to not placing them in the correct position or in the correct orientation is greatly reduced. In addition, the folds in the underlying fibre layer can be gradually treated during the process. Existing approaches suffer from all of these problems.

In some embodiments, contacting the spar cap components with one or more of the outer skin fiber layers ends with contacting the second ends of the spar cap components with one or more of the outer skin fiber layers.

In some embodiments, the step of contacting the spar cap components with one or more of the outer skin fiber layers begins at a first location in the mold and ends at a second location in the mold, wherein the first location is closer to the tip end of the blade than the second location. In other words, the first end is proximate to the distal end of the housing component and the second end is proximate to the root end. The housing component is typically relatively narrow at the distal end. Embodiments of the present invention that first contact the spar cap components with the fiber layers in a location near the tip make the process of adding the spar cap components easier.

In some embodiments, the step of gradually bringing the spar cap components into contact with one or more of the outer skin fiber layers comprises:

placing the spar cap parts on one or more support members arranged above the outer skin fibre layers at the location of the respective support member, each support member supporting and separating the spar cap parts from the outer skin fibre layers,

-displacing the support member so as to gradually bring the spar cap parts into contact with the outer skin fibre layer, and

-removing the support member from below the spar cap components.

These bracing members distance the spar cap components from the fiber layers. However, this allows personnel to work around the spar cap components, except where they engage the support members. In embodiments where one or more straps are used to tie unbonded pre-cure elements together, the support members allow for personnel space to remove the one or more straps.

Some embodiments employ at least two support members.

In some embodiments, the two support members have a mutual distance in the range of 1-3m, such as in the range of 1.5-2.5 m.

In some embodiments, the support members are arranged in an array at a substantially equal distance from one support member to the next. In some embodiments, the distance is in the range of 1-3m, such as in the range of 1.5-2.5 m.

In some embodiments, the step of progressively displacing the bracing members comprises displacing a first bracing member disposed closest to the first end of the spar cap and removing subsequent bracing members until all bracing members have been removed from beneath the spar cap. In some embodiments, the support members are removed individually starting from a first support member arranged closest to the first end of the spar cap components and proceeding sequentially along the spar cap components towards the second end of the spar cap components. This allows for a very controlled process, since the spar cap parts are passively supported by the support members. This has the advantage that once the process has been initiated, there is no need to continuously manoeuvre and lower the spar cap parts. The method according to the invention is not susceptible to this problem.

In some embodiments, one or more support members are supported by an edge of the mold. The edges of the mold are typically used to define the leading and trailing edges of the shell member and to support the resin infusion and air evacuation equipment during the formation of the composite material. However, the rim is well suited for use in embodiments of the invention, particularly for supporting the above-mentioned support members.

In some embodiments, the support member is a roller. The support member may be made of cardboard or plastic or metal, for example. In some cases, a smooth surface may be advantageous because it makes the roller easier to remove.

In some embodiments, the pre-cured reinforcing elements have a stackable shape. For example, the pre-cured reinforcing elements may have a rectangular cross-section, such as a uniform cross-section along their entire length.

In some embodiments, one or more of the pre-cure reinforcement elements comprise a chamfered first end and/or a chamfered second end.

In some embodiments, one or more of the pre-cured reinforcing elements are fiber reinforced composite pultrudates. Pultrusion may replace at least a portion of the laid fibres in the mould and pultrusion is relatively easy to manufacture as most pultrusion processes are largely automated and the resulting elements have low variability.

In some embodiments, the spar cap components comprise carbon fibers.

In some embodiments, the spar cap components comprise fiberglass.

Other fiber types, such as steel fibers, may alternatively or additionally be used. Any combination of fiber types may be used.

In some embodiments, one or more of the outer skin fiber layers comprise glass fibers and/or carbon fibers. Other types of fibers may be used.

In some embodiments, one or more of the outer skin fiber layers comprise a woven material, such as a uniaxial and/or biaxial and/or triaxial material.

In some embodiments, the step of bringing the spar cap components into contact with one or more of the outer skin fibre layers is preceded by the step of suspending the spar cap components over the mould by means of at least two suspension devices, and the step of bringing the spar cap components into contact with one or more of the outer skin fibre layers comprises lowering the suspension devices such that the spar cap components are gradually brought into contact with one or more of the outer skin fibre layers starting from the first end.

In some embodiments, the suspension device is in turn attached to the lifting beam.

The lowering means allows the suspension device to be lowered gradually and in a controlled manner down to the fibre layer. The lowering means may for example be a cable attached to the lifting beam and to the suspension device, or the lifting beam may be height adjustable.

In some embodiments, one or more of the suspension devices comprises a looped cable (strop) surrounding the spar cap members.

In some embodiments, the spar cap components comprise a plurality of reinforcing elements arranged in a plurality of layers, each layer comprising a plurality of reinforcing elements.

In some embodiments, the provided spar cap components comprise a plurality of pre-cured reinforcing elements that are not bonded together but are tied together by one or more straps, and the one or more straps are removed during at least a portion of the step of gradually bringing the spar cap components into contact with one or more of the outer skin fiber layers. The belt holds the plurality of pre-cured reinforcing elements in a fixed configuration relative to one another. In other words, the belt prevents displacement of the plurality of pre-cured reinforcing elements relative to each other. By removing the tape only during the step of gradually bringing the spar cap parts into contact with one or more of the outer skin fibre layers, the risk of displacement of the pre-cured reinforcing elements relative to each other is greatly reduced.

In some embodiments, the reinforcing element is strip-shaped or plate-shaped.

In some embodiments, the spar cap components have a width in the range of 10-1000mm, such as in the range of 50-500 mm.

In some embodiments, the spar cap components have a height in the range of 5-200mm, such as in the range of 5-100 mm. This height may also be considered as a thickness, which is added to the thickness of the shell parts at the location where the spar cap parts are placed.

The width and/or thickness may be constant along the entire length of the spar cap components, or the width and/or thickness may vary along the length of the spar cap components.

In some embodiments, one or more of the reinforcing elements have a length in the range of 3-200 m.

A second aspect of the invention provides a wind turbine blade shell member obtainable by a method according to an embodiment of the first aspect of the invention.

Drawings

The invention is explained in detail below with reference to embodiments shown in the drawings.

FIG. 1 is a schematic diagram illustrating an exemplary wind turbine.

FIG. 2 is a schematic diagram illustrating an exemplary wind turbine blade.

FIG. 3 is a schematic diagram illustrating a cross-section of an exemplary wind turbine blade.

FIG. 4 is a schematic diagram illustrating an exemplary wind turbine blade shell member mold.

FIG. 5 is a schematic diagram illustrating a cross-section of a shell component mold having fiber layers and a pre-cure element.

Fig. 6A-6L illustrate a method for arranging a pre-cure element on a fiber layer arranged in a shell part mold according to an embodiment of the invention.

Fig. 7A-7G illustrate a method for arranging a pre-cure element on a fiber layer arranged in a shell part mold according to an embodiment of the invention.

Detailed Description

Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Like reference numerals may refer to like elements throughout. The drawings illustrate selected ways of implementing the invention and should not be construed as limiting. The drawings are not necessarily drawn to scale unless otherwise indicated. The dimensions of the different elements and their shapes may be chosen so that the different elements are clearly distinguishable.

Fig. 1 illustrates a conventional modern upwind wind turbine 2 according to the so-called "danish concept", having a tower 4, a nacelle 6 and a rotor with a substantially horizontal rotor shaft. The rotor comprises a hub 8 and three blades 10 extending radially from the hub 8, each blade having a blade root 16 closest to the hub and a blade tip 14 furthest away from the hub 8. The invention is not limited to use in this type of wind turbine.

FIG. 2 illustrates a schematic view of an exemplary wind turbine blade 10. The wind turbine blade 10 has the shape of a conventional wind turbine blade with a root end 17 and a tip end 15 and comprises a root region 30 closest to the hub, a profiled or airfoil region 34, and a transition region 32 between the root region 30 and the airfoil region 34. The blade 10 comprises a leading edge 18 facing the direction of rotation of the blade 10 when the blade is mounted on the hub, and a trailing edge 20 facing the opposite direction of the leading edge 18.

The airfoil region 34 (also referred to as profiled region) preferably has an ideal shape with respect to generating a hub rotation, whereas the root region 30 has a substantially circular or elliptical cross-section due to structural considerations, which e.g. makes it easier and safer to mount the blade 10 to the hub. The diameter of the root region 30 may be constant along the entire root region 30. In this example, the transition region 32 present in the wind turbine blade 10 has a transition profile gradually changing from the circular shape of the root region 30 to the airfoil profile of the airfoil region 34. The chord length of the transition region 32 generally increases in the direction outward from the hub. The airfoil region 34 has an airfoil profile with a chord extending between the leading edge 18 and the trailing edge 20 of the blade 10.

It should be noted that different sections of the blade generally do not have a common plane, as the blade may twist and/or bend (i.e. pre-bend) in a direction from the root region to the tip, which is most often the case, for example, in order to more or less compensate for local velocities of the blade depending on the distance from the hub.

The wind turbine blade 10 comprises a blade shell, which may for example comprise two blade shell parts, a first blade shell part 24 and a second blade shell part 26, which for example are at least partly made of a fiber reinforced polymer. The first blade shell member 24 may be part of a pressure side or upwind blade member, for example. The second blade shell member 26 may for example be a suction side or part of a downwind blade member. The first and second

blade shell parts

24, 26 are typically joined together (such as glued together) along a bond line or glue joint 28 extending along the trailing and leading

edges

20, 18 of the blade 10. Typically, the root ends of the

blade shell members

24, 26 have a semi-circular or semi-elliptical outer cross-sectional shape which, when the first and second shell members are joined, forms a root region, such as a circular or elliptical root region.

FIG. 3 isbase:Sub>A schematic diagram illustratingbase:Sub>A cross-sectional view of an exemplary wind turbine blade 10, which corresponds to line A-A in FIG. 2. The wind turbine blade 10 includes a shear web 40, a first spar cap 74 (which is part of the pressure side 24 of the blade 10), and a second spar cap 76 (which is part of the suction side 26 of the blade 10). The spar caps provide structural strength to the blade and generally extend along the blade in a spanwise direction. Typically, the spar caps will extend over 60-95% of the blade length. Also indicated in fig. 3 are the trailing edge 20 and the leading edge 18.

Increasingly, spar caps are made at least partially using prefabricated reinforcing elements, such as fiber-reinforced composites. These may be made separately in a variety of ways, such as by manual, semi-automatic, or automatic processes. Another option is to use a pultrusion process to manufacture the reinforcing elements. The prefabricated element replaces some of the fibre mats that would otherwise need to be laid down during the manufacturing of the wind turbine blade.

Fig. 4 illustrates a mold 80 for manufacturing a blade shell member, such as the

shell member

24 or 26 illustrated in fig. 2 and 3. As part of the manufacturing process, a layer of dry fibres 81 (comprising for example fibre mats) is laid in the blade shell part mould 80. These will constitute the outer skin of the shell parts. After the addition of the fiber layers 81, one or more pre-cured elements 82 (such as spar cap components) may be added to form the reinforcing component of the blade.

Arranging the spar cap components 82 on the fiber layers 81 is tedious and the fiber layers 81 often become dislodged or wrinkled during the process of arranging the spar cap components on the fiber layers 81.

Fig. 5 illustrates a cross-section of the mold 80 of fig. 4 corresponding to the line B-B indicated in fig. 4. Fig. 5 shows in perspective how a pre-manufactured element 82 has been arranged on a fibre layer 81 in a mould 80. In this example, spar cap components 82 comprise two stacked four panels made from, for example, glass and/or carbon fiber reinforced composite materials using a pultrusion process. Since current wind turbine blades are easily 70m long and blades with a length exceeding 100m are currently being provided, the plates are correspondingly long, having a length typically in the range of 60-95% of the entire length of the blade. Therefore, the pultrusion 82 is difficult to handle and arrange. When there are several elements, as in this example, arranging the pultrusion 82 on the fibre layer 81 is even more tedious, since the pultrusions 82 may be displaced relative to each other. Embodiments of the present invention alleviate this problem.

Fig. 6A shows a cross-section C-C indicated in fig. 4, in the spanwise direction of a mould 80 with fibre layers 81 and through a stack of pultrudates 82. In fig. 6A, the pultrusion is carried by a lifting beam 101. The pultrusion 82 has been picked up from another location and the elevator is then arranged above the mould or above the mould below the lifting beam 101 and in a position where the pultrusion 82 is to be delivered into the mould 80. The pultrusion 82 may be retained, for example, by a looped cable or other suitable suspension device indicated by

elements

111 and 112. The pultrusions may additionally be tied together. By tying the elements together, they do not shift relative to each other during the process. The straps are not shown in the drawings but may be placed anywhere along the pultrusion 82 to hold them together if desired.

Rollers

91, 92, 93 are arranged on the edges of the mould 80 to initially support the pultrudate 82 before they finally descend onto the fibre layer 81. The rollers may be made of cardboard or plastic or other suitable material. The smooth surface makes the roller easier to remove during machining.

Fig. 6A also illustrates the first and

second ends

82a, 82b of the spar cap components.

Fig. 6B illustrates the cross-section D-D indicated in fig. 6A. The cross-section is the same as the cross-section indicated by line B-B in fig. 3. As described in relation to fig. 6A, the pultrusion 82 is carried by

suspension devices

111, 112 attached to the lifting beam 101. Fig. 6B shows in perspective view a pultrusion 82 suspended above the die 80 and the fibre layer 81. For simplicity, the

suspension devices

111, 112 and the lifting beam 101 are not included in the figure. Fig. 6B shows the

rollers

91, 92, 93 in the same cross-section C-C (defined in fig. 4).

Fig. 6C shows the pultrusion which has been lowered so as to be supported by the

rollers

91, 92, 93. The rollers allow a person to remove the

suspension devices

111, 112 from the pultrusion 82. As mentioned above, the pultrudates may also be bundled together, and some or all of such strips may be easily removed since the bottom side of the pultrudate 82 is now accessible (accessible). As can be seen in fig. 6C, pultrudates are typically somewhat curved due to their flexible nature. The degree of curvature in the pultrusion 82 is exaggerated in the drawings for illustrative purposes.

Fig. 6D shows a cross-section D-D corresponding to the step shown in fig. 6C. Since the pultrusion for the wind turbine blade is very flexible, there will be a bending when the pultrusion rests on the

rollers

91, 92, 93. In the example of fig. 6C-6D, there is a slight bend in the pultrusion. The present invention takes advantage of this characteristic.

Because the roller 91 in fig. 6D is very close to the first end 82a of the pultrusion 82, the bending is relatively small. However, by removing the rollers or displacing them along the pultrusion 82 towards the second end 82b, the first end 82a will eventually be able to come into contact with the fibre layer 81.

One way to do this from fig. 6C-6D is to loosen the suspension device 111 closest to the first end 82a of the pultrusion 82, as shown in fig. 6E. Then, as shown in fig. 6F, the roller 91 closest to the first end 82a is removed. This brings flexible pultrusion 82 into final contact with fibrous layer 81 as shown in fig. 6F.

The number of rollers and the number of suspension devices are adjusted to take into account the length of the pultrudates and their elastic properties. By using more rollers and suspension devices, the process requires less lifting to be performed, for example by personnel.

The reason for performing the steps of fig. 6D and 6E in this order is that the suspension device 111 would otherwise support the pultrusion 82 from the first end 82a to the suspension device 111 all the way, making it difficult to remove the suspension device 111 in a controlled manner.

Fig. 6G illustrates the configuration in fig. 6F as seen in cross-section D-D (see fig. 6A). The pultrusion 82 is now partially in contact with the fibre layer 81. During this process, the pultrusion 82 may be displaced as desired. For example, if desired, pultrudates 82 may be moved laterally toward the leading edge (moving them to the right in the view of FIG. 6G) or toward the trailing edge (moving them to the left in the view of FIG. 6G). At this point, span-wise adjustment is also easily performed, since only a small portion of the pultrusion is in contact with the fibre layer 81 and can therefore be adjusted quickly. This allows a very precise placement of the pultrusion 82 onto the fibre layer 81. Fig. 6G also shows

rollers

91 and 92 still supporting portions of pultrusion 82.

Another advantage of this method is that any undesired wrinkling in the fibre layer 81 is very easily monitored by means of a continuously gradual manner, wherein the pultrusion 82 is brought into contact with the fibre layer 81. Monitoring is mostly required at the point where the pultrusion 82 is currently in contact with the fibre layer 81. Then, if any wrinkles are observed, steps may be taken to reduce or eliminate the wrinkles, or fiber material may be added (or in some cases removed) to compensate for any distortion that the pultrusion may produce on fiber layer 81.

Next, as shown in fig. 6H, the next suspension device 112 is released from the pultrusion 82, similar to the step shown in fig. 6E for the first suspension device 111. The tape holding the pultrusion together may also be removed prior to bringing the next portion of pultrusion 82 into contact with fibrous layer 81.

As a next step, shown in fig. 6I, the next roller 92 is removed. This brings the flexible pultrusion 82 further into contact with the fibre layer 81 as seen in fig. 6I.

Fig. 6J illustrates the configuration in fig. 6F as seen in cross-section D-D (see fig. 6A). The pultrusion now comes further into contact with the fibre layer 81 while still being supported at the distal end by the roller 93.

Finally, the last roller 93 is removed from under the pultrusion 82, thereby completing the process of arranging the pultrusion 82 on the fiber layer 81, ending with the second end 82b of the pultrusion in contact with the fiber layer 81, as shown in fig. 6K. Fig. 6L shows the configuration as seen in cross-section D-D.

Depending on the number of rollers and the configuration of the pultrusion, it may be required to remove the rollers by simply pulling them sideways (e.g. to the left or right in the perspective view shown in fig. 6L) or it may be required to displace the rollers in a gradual manner towards the second end 82b of the pultrusion. In this case, a smooth roller may be advantageous.

As can be seen from the above description, the method provides that the pre-cured element can be arranged on the fibre layer in the mould in a highly controllable manner.

This process may also be performed without a support member (such as the roller described above). Figures 7A-7G illustrate embodiments of the present invention that do not rely on a support member.

As illustrated in fig. 7A, the pultrusion 82 is initially suspended above the die 80 using

suspension devices

111, 112, 113 held in the lifting beam 101. No rollers are arranged to support the pultrudates 82 and separate them from the fibre layer 81. Instead, the method relies on a gradual lowering of the

suspension devices

111, 112, 113 in such a way that the first end 82a is in contact with the fibre layer 81 as a first part of the pultrusion 82. This is illustrated in fig. 7B. The first suspension device 111 is released from the pultrusion and removed, typically with human intervention, as illustrated in fig. 7C.

As shown in fig. 7D, the pultrusion is then further lowered by lowering the

suspension devices

112 and 113 until the suspension devices 112 are very close to the fibre layer 81. Similar to the hanging device 111, the hanging device 112 is then released and then removed, as illustrated in fig. 7E.

Next, as shown in fig. 7F, the suspension device 113 is lowered until the pultrusion 82 is very close to the fibre layer 81.

Then, as shown in fig. 7G, the suspension device 113 is removed and moved away. In this last step, the second end 82b is brought into contact with the fiber layer as the last part of the pultrusion 82. The process of placing pultrusion 82 on the fiber layer is completed.

After the fiber layer 81 and pultrusion 82 have been set in the die 80, any other layers and/or components are added to the layup (layup), including for example the fiber layer forming the inside of the shell component. To complete the blade shell component, liquid resin is added and the component is cured.

The process may be, for example, a vacuum assisted resin transfer molding process in which a flexible vacuum bag is placed on top of the layup and sealed against the mold 80, thereby forming a mold cavity containing the layup. The resin inlet and vacuum outlet are connected to the chamber in preparation for a process known as infusion. The inlet allows resin to be introduced into the mold cavity, while the outlet allows air to be removed. The cavity is evacuated via a vacuum outlet, creating an evacuation in the mold cavity. Then, a supply of liquid resin is provided via the resin inlet. The resin is forced into the mold cavity at least due to the pressure differential created by the evacuation. Due to the negative pressure, the resin is dispersed in the mould cavity in different directions, which drives the resin flow front towards the vacuum outlet. In the mold cavity, the resin impregnates the layup. When the lay-up is fully impregnated, the resin is cured, thereby forming a fibre reinforced composite wind turbine shell part.

REFERENCE LIST

2 wind turbine

4 tower frame

6 nacelle

8 hub

10 blade

14 blade tip

15 distal end

16 blade root

17 root end

18 leading edge

20 trailing edge

24 first blade housing part (pressure side)

26 second blade housing part (suction side)

28 Joint line/glue Joint

30 root zone

32 transition region

34 airfoil region

34a first airfoil region

34b second wing region

40 spar side of a shear web or spar box

44 first blade segment

45 interface between first and second blade sections

46 second blade section

74 first spar cap

76 second spar cap

80 wind turbine blade shell part mould

81 fiber layer

82 Pultrusion(s), spar cap component, pre-cured element(s)

82a first end of the pre-cured part

82b pre-cure component second end

91-93 Rollers, support Member

101 lifting beam

111-113 suspension device

Claims

1. A method for manufacturing a wind turbine blade shell member (26) having a tip end (14) and a root end (16), comprising:

-laying one or more outer skin fibre layers (81) in a wind turbine blade shell part mould (80),

-providing a spar cap component (82) comprising one or more pre-cured elongated reinforcing elements, the spar cap component having a first end (82 a) and a second end (82 b),

-gradually bringing the spar cap parts into contact with one or more of the outer skin fibre layers (81) starting from the first end (82 a),

-laying down one or more inner skin fibre layers in contact with the spar cap parts (82),

-providing a liquid resin into the mould and curing the resin, thereby obtaining the wind turbine blade shell part.

2. The method according to claim 1, wherein contacting the spar cap components (82) with one or more of the outer skin fiber layers (81) ends with contacting the second ends (82 b) of the spar cap components (82) with one or more of the outer skin fiber layers.

3. A method according to any of the preceding claims, wherein contacting the spar cap components with one or more of the outer skin fibre layers starts at a first position in the mould (80) and ends at a second position in the mould (80), wherein the first position is closer to the tip end (14) of the blade than the second position.

4. The method according to any of the preceding claims, wherein the step of gradually bringing the spar cap components (82) into contact with one or more of the outer skin fibre layers (81) comprises:

-placing the spar cap parts (82) on one or more support members (91, 92, 93) arranged above the outer skin fibre layer at respective support member positions, each support member (91, 92, 93) supporting and separating the spar cap parts from the outer skin fibre layer (81),

-displacing the support members (91, 92, 93) so as to gradually bring the spar cap parts into contact with the outer skin fibre layer, and

-removing the support member from below the spar cap components.

5. A method according to claim 4, wherein the step of gradually displacing the bracing members (91, 92, 93) comprises displacing a first bracing member arranged closest to the first end of the spar cap components and removing subsequent bracing members until all bracing members have been removed from under the spar cap components (82).

6. A method according to claim 4 or 5, wherein the support members are removed individually starting from a first support member arranged closest to the first end (82 a) of the spar cap components and proceeding sequentially along the spar cap components towards the second end (82 b) of the spar cap components (82).

7. A method according to any of claims 4-6, wherein one or more support members are supported by the edge of the mould.

8. The method of any of claims 4-7, wherein the support members are rollers.

9. The method according to any one of the preceding claims, wherein one or more of the pre-cured elongate reinforcing elements have a rectangular cross-section.

10. The method according to any one of the preceding claims, wherein one or more of the precured elongated reinforcing elements comprises a chamfered first end (82 a) and/or a chamfered second end (82 b).

11. The method of any preceding claim, wherein one or more of the pre-cured reinforcing elements are fibre reinforced composite pultrudates.

12. The method of any preceding claim, wherein the spar cap components comprise carbon fibres.

13. The method of any preceding claim, wherein the spar cap components comprise fiberglass.

14. The method according to any one of the preceding claims, wherein one or more of the outer skin fibre layers (81) comprise glass fibres and/or carbon fibres.

15. The method according to any one of the preceding claims, wherein one or more of the outer skin fibre layers comprise a woven material, such as a uniaxial and/or biaxial and/or triaxial material.

16. A method according to any of the preceding claims, wherein prior to the step of bringing the spar cap parts into contact with one or more of the outer skin fibre layers (81), the spar cap parts (82) are suspended above the mould (80) by means of at least two suspension devices (111, 112, 113), and the step of bringing the spar cap parts into contact with one or more of the outer skin fibre layers comprises lowering the suspension devices so that the spar cap parts come into contact gradually with one or more of the outer skin fibre layers starting from the first end (82 a).

17. A method according to claim 15 or 16, wherein one or more of the suspension devices (111, 112, 113) comprises a loop cable surrounding the spar cap parts.

18. The method according to any of the preceding claims, wherein the spar cap components comprise a plurality of reinforcing elements arranged in a plurality of layers, each layer comprising a plurality of reinforcing elements.

19. A method according to any of the preceding claims, wherein the provided spar cap components comprise a plurality of reinforcing elements that are not bonded together but are taped together by one or more tapes, and the one or more tapes are removed during at least part of the step of gradually bringing the spar cap components into contact with one or more of the outer skin fibre layers.

20. The method according to any of the preceding claims, wherein the reinforcing element is strip-shaped or plate-shaped.

21. A method according to any of the preceding claims, wherein the spar caps have a width in the range of 50-1000 mm.

22. A method according to any of the preceding claims, wherein the spar caps have a height in the range of 5-100 mm.

23. The method according to any one of the preceding claims, wherein one or more of the reinforcement elements have a length in the range of 3-200 m.

24. A wind turbine blade shell part obtainable by a method according to any of claims 1-23.