The present disclosure relates to wind turbine blades and manufacture of wind turbine blades. More specifically, the present disclosure pertains to the field of manufacturing of wind turbine blades, such as manufacturing of blade shell sections of wind turbine blades.

BACKGROUND

As the demand for sustainable energy increases, the demand for recyclable material in the wind turbine blades increases. Furthermore, the material used during the manufacturing of the wind turbine blade also needs to be recyclable.

The conventional wind turbine blades are made of a thermoset material of fibre reinforced composite material which is infused with a resin which cures. The thermoset material is not suitable for recycling, thus large wind turbine blades are simply discarded if they are damaged or produced with defects.

Conventional wind turbine blades are manufactured in large moulds where the pressure side shell half part and the suction side shell half part of the blade are manufactured separately in each of the two moulds. Afterwards, one of the moulds are turned upside down and positioned on top of the other mould, and the two halves are adhered together. When a new blade design is introduced, a new mould is manufactured and the mould for the old design is discarded.

Thus, there is a need for more sustainable ways of manufacturing wind turbine blades which live up to the increasing demand for circular economy and recyclable materials.

SUMMARY OF THE INVENTION

It is an object of the present disclosure to provide a blade shell section and a wind turbine blade comprising a blade shell section which overcome or ameliorate at least some of the disadvantages of the prior art or which provide a useful alternative.

In particular, it is an object of the present invention to provide a blade shell section for a wind turbine blade comprising a thermoplastic material and a method for manufacturing a blade shell section for a wind turbine blade comprising a thermoplastic material. Thus, the present invention relates to a method for manufacturing a blade shell section, such as at least a part of a suction side or a pressure side blade shell section, for a wind turbine blade. The method comprises the steps of providing a panel section as a sandwich construction made of a fibre-reinforced thermoplastic material and comprising a core material sandwiched between two fibre-reinforcement sheets. The first fibre-reinforced sheet forms an inner surface and the second fibre-reinforced sheet forms an outer surface. The first fibre-reinforcement sheet and/or the second fibre-reinforcement sheet may be distinct from the core.

The method comprises heating the panel section. The method comprises curving at least a first part of the panel section. The method comprises compressing at least a second part of the panel section. Compressing the second part of the panel section may comprise compressing the core material of the panel section.

The steps of the method form the blade shell section. The blade shell section comprises a first part, a second part, a longitudinal direction between a first end and a second end and a traverse direction between a first side and a second side. The blade shell section has an inner surface, a curved outer surface and a varying thickness.

It is an advantage of the present disclosure that the blade shell part is made of a thermoplastic material, which may be easily shaped, e.g. with heat and pressure, to accommodate the complex shape of a wind turbine blade though starting from for example flat panels which may be made in a continuous flow process by a general plastics supplier and thus of low cost.

It is clear that the first part and second part may be at least partly overlapping. In other words, a part may both be curved and having a varying thickness.

Also disclosed is a blade shell section for a wind turbine blade. The blade shell section comprises a longitudinal direction between a first end and a second end, and a traverse direction between a first side and a second side. The blade shell section is made from a sandwich construction made of a fibre-reinforced thermoplastic material and comprising a core material sandwiched between two fibre-reinforcement sheets. The first fibre-reinforced sheet forms an inner surface and the second fibre-reinforced sheet forms an outer surface. The blade shell section has been shaped so as to have a curved outer surface and a varying thickness. The core material of the blade shell section may vary in thickness. The two fibre-reinforced sheets may alternatively have constant thickness. The outer surface may correspond to the outer surface of the wind turbine blade. The inner surface may correspond to the inner surface of the wind turbine blade.

It is a further advantage of the present disclosure that the environmental footprint of wind turbine blades is reduced. Furthermore, cost of manufacturing may be reduced as materials may be recycled and reused in new wind turbine blades. In addition, investments in equipment for manufacturing may be reduced as the same machine may be used to manufacture different types of wind turbine blades. In contrast, conventional moulds used to cast the conventional wind turbine blades are only suitable to manufacture a specific type of blade and the moulds are not possible to recycle.

The core material has a honeycomb or a foam structure and is made of a thermoplastic material, such as one or more of acrylic, polypropylene, PET (Polyethylene terephthalate), polyamide. The core may be a honeycomb or a foam structure comprising a thermoplastic material such as one or more of acrylic, polypropylene, PET (Polyethylene terephthalate), polyamide. The core of the panel section or the blade shell section is configured to be compressed. The core of the panel section or the blade shell section is configured to be bent, e.g. curved.

The fibre-reinforcement sheets are made of a thermoplastic material comprising one or more of acrylic, polypropylene, PET (Polyethylene terephthalate), polyamide. The fibre reinforcement sheets may comprise a thermoplastic material, such as one or more of acrylic, polypropylene, PET (Polyethylene terephthalate), polyamide. The fibre-reinforcement sheets are configured to be bent, e.g. curved.

Providing the panel section may comprise providing a first fibre-reinforcement sheet, a second fibre-reinforcement sheet and the core material. The first sheet, second sheet and the core may be bonded by heating. The first fibre-reinforcement sheet, the second fibre-reinforcement sheet and the core material may be fused such that the core is fused between the first sheet and the second sheet. The first sheet, second sheet and the core material may be fused during heating of the panel section.

The blade shell section may comprise a first part being curved.

The blade shell section may comprise a second part being compressed. For example, the thickness between the outer surface and the inner surface of a second part of the blade shell section may decrease along a transverse direction towards the first side. The method may comprise compressing at least a second part of the panel section. Compressing the second part of the panel section may comprise compressing the core material of the panel section.

The blade shell section may comprise a third part being compressed. For example, the thickness between the outer surface and the inner surface of a third part of the blade shell section may decrease along a transverse direction towards the second side. The method may comprise compressing at least a third part of the panel section. Compressing the third part of the panel section may comprise compressing the core material of the panel section. The blade shell section may comprise a fourth part being compressed. For example, the thickness between the outer surface and the inner surface of a fourth part of the blade shell section may decrease along a transverse direction towards a first position between the first side and the second side. The method may comprise compressing at least a fourth part of the panel section. Compressing the fourth part of the panel section may comprise compressing the core material of the panel section.

The blade shell section may comprise a fifth and/or sixth part being compressed. For example, the thickness between the outer surface and the inner surface of the fifth and/or sixth part of the blade shell section may decrease along a longitudinal direction towards the first end and/or the second end. Compressing the fifth and/or sixth part of the panel section may comprise compressing the core material of the panel section.

Curving at least the first part of the panel section may comprise applying pressure to curve the panel section, e.g. by means of controlled actuators comprising a forming unit. Compressing the second part, third part, fourth part, fifth part and/or the sixth part of the panel section may comprise applying pressure to the second part, third part, fourth part, fifth part and/or the sixth part such that the thickness between the outer surface and the inner surface of the part of the blade shell section decreases towards the first side and/or the second side, or the first end and/or second end. The part may be compressed by means of controlled actuators comprising a forming unit. The forming unit may comprise one or more or a combination of rollers, clamps, shoes, or belts over rollers or similar means for forming with pressure. The forming unit may comprise a low friction surface.

The panel section may be heated prior to compressing. Heat may be provided by any suitable heat sources, such as a bank of radiant heaters. Alternatively, the forming unit of the actuators may be heated.

The actuators may be computer controlled and set to vary the pressure across the panel in the longitudinal direction and/or the transverse direction.

The method may comprise cutting the panel section. The panel section may be cut in the longitudinal direction, e.g. the lengthwise direction of the panel section. The panel section may be cut in the transverse direction, e.g. in the direction of the width of the panel section. The panel section may be cut to accommodate the shape of a wind turbine blade where the width of the blade decreases towards the tip end. The cutting may be performed by methods known in the art of cutting thermoplastic panel sections. The panel section may be cut before heating, curving and/or compressing the panel section. The method may comprise treating the outer surface of the blade shell section with a film, gel coat or a paint. Treatment of the outer surface of the blade shell section may protect the complete wind turbine blade against erosion.

The blade shell section may correspond to a suction side blade shell part or a pressure side blade shell part of a wind turbine blade.

The blade shell section may be a segmented section comprising a first blade shell section and a second blade shell section. The first blade shell section and the second blade shell section may be connected by welding, e.g. plastic welding, or adhesive. The first blade shell section and the second blade shell section may be arranged in a longitudinal direction. Alternatively, the first blade shell section and the second blade shell section may be arranged in a transverse direction.

Also disclosed is a method for manufacturing a wind turbine blade. The method comprises the steps of manufacturing a first blade shell section, such as a blade shell section as disclosed above, and assembling the first blade shell section with other separately manufactured blade parts to form the wind turbine blade. The first blade shell section may correspond to a suction side blade shell part or a pressure side blade shell part. The other parts may be a leading edge section or a trailing edge section. The other parts may be a part of a suction side blade shell part or a part of a pressure side blade shell part.

The method may comprise the steps of manufacturing a second blade shell section, such as a blade shell section as disclosed above, and connecting the first blade shell section and the second blade shell section, e.g. by welding or applying an adhesive. The second blade shell section may correspond to a suction side blade shell part or a pressure side blade shell part. The first blade shell section may correspond to a pressure side blade shell part and the second blade shell section may correspond to a suction side blade shell part.

Connecting the first blade shell section and the second blade shell section may comprise welding the first side of the first blade shell section with the second side of the second blade shell section. For example, a joint between the first blade shell section and the second blade shell section may be welded. An intermediate fibre-reinforced thermoplastic part may be applied such that it covers part of the first side of the first blade shell section and part of the second side of the second blade shell section and welded to the first blade shell section and the second blade shell section.

Alternatively, the first blade shell section and the second blade shell section may be connected by applying an adhesive. The adhesive may be applied at an overlapping part of the blade shell sections or an intermediate part covering the first side of the first blade shell section and the second side of the second blade shell section. It is envisaged that any embodiments or elements as described in connection with any one aspect may be used with any other aspects or embodiments, mutatis mutandis.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the invention will be described in more detail in the following with regard to the accompanying figures. Like reference numerals refer to like elements throughout. Like elements may, thus, not be described in detail with respect to the description of each figure. The figures show one way of implementing the present invention and are not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

Fig. 1 is a schematic diagram illustrating an exemplary wind turbine,

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

Figs. 3a-3b are schematic diagrams illustrating a cross sectional view of an exemplary wind turbine blade

Figs. 4a-4c are schematic diagrams illustrating an exemplary panel section,

Figs. 5a-5b are schematic diagrams illustrating an exemplary blade shell section and part of a blade shell section,

Figs. 6a-6b are schematic diagrams illustrating an exemplary forming station, and

Figs. 7a-7b are block diagrams of exemplary methods.

DETAILED DESCRIPTION

In the following figure description, the same reference numbers refer to the same elements and may thus not be described in relation to all figures.

Fig. 1 illustrates a conventional modern upwind wind turbine 2 according to the so-called "Danish concept" with a tower 4, a nacelle 6 and a rotor with a substantially horizontal rotor shaft. The

RECTIFIED SHEET (RULE 91) ISA/EP rotor includes a hub 8 and three blades 10 extending radially from the hub 8, each having a blade root 16 nearest the hub and a blade tip 14 furthest from the hub 8.

Fig. 2 shows 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 an airfoil region 34 furthest away from the hub 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 called the profiled region) has an ideal or almost ideal blade shape with respect to generating lift, whereas the root region 30 due to structural considerations has a substantially circular or elliptical cross-section, which for instance makes it easier and safer to mount the blade 10 to the hub. The diameter (or the chord) of the root region 30 may be constant along the entire root area 30. The transition region 32 has a transitional profile gradually changing from the circular or elliptical shape of the root region 30 to the airfoil profile of the airfoil region 34. The chord length of the transition region 32 typically increases with increasing distance r 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. The width of the chord decreases with increasing distance r from the hub.

A shoulder 40 of the blade 10 is defined as the position, where the blade 10 has its largest chord length. The shoulder 40 is typically provided at the boundary between the transition region 32 and the airfoil region 34.

It should be noted that the chords of different sections of the blade normally do not lie in a common plane, since the blade may be twisted and/or curved (i.e. pre-bent), thus providing the chord plane with a correspondingly twisted and/or curved course, this being most often the case in order to compensate for the local velocity of the blade being dependent on the radius from the hub.

The wind turbine blade 10 comprises blade shell sections 50, such as a first blade shell section 50A and a second blade shell section 50B. The first blade shell section 50A may form at least part of a first blade shell part 24. The second blade shell section 50B may form at least part of the second blade shell part 26. The first blade shell part 24 is typically a pressure side or upwind blade shell part. The second blade shell part 26 is typically a suction side or downwind blade shell part. Typically, the root ends of the blade shell parts 24, 26 have a semi-circular or semi-oval outer cross-sectional shape. The first blade shell section 50A extends in a longitudinal direction between a first end 52A and a second end 54A. The second blade shell section 50B extends in a longitudinal direction between a first end 52B and a second end 54B. The blade shell sections 50 are made of a fibre-reinforced thermoplastic material and formed to the shape of a wind turbine blade shell section.

The first blade shell section 50A and/or the second blade shell section 50B may have a length in a longitudinal direction corresponding to the length of the wind turbine blade 10. Alternatively, the pressure side blade shell part 24 may comprise a plurality of blade shell sections 50 such as a first blade shell section 50A and a third blade shell section 50C arranged in series in the longitudinal direction of the wind turbine blade 10. The suction side blade shell part 26 may comprise a plurality of blade shell sections 50 such as a second blade shell section 50B and a fourth blade shell section 50D arranged in series in the longitudinal direction of the wind turbine blade 10. The blade shell sections 50 may be connected by welding or by adhesive. Further, individual blade sections may be connected by a pin joint connection in an internal spar structure.

Fig. 3a-3b are schematic diagrams illustrating a cross sectional view of an exemplary wind turbine blade 10, e.g. a cross-sectional view of the airfoil region of the wind turbine blade 10 at the line 3 of Fig. 2. The wind turbine blade 10 comprises a leading edge 18, a trailing edge 20, a pressure side 24, and a suction side 26. The wind turbine blade 10 comprises shear webs 42, such as a leading edge shear web and a trailing edge shear web. The wind turbine blade 10 comprises spar caps 41 with the shear webs arranged between them. Alternatively, the shear webs 42 could be a spar box with spar sides, such as a trailing edge spar side and a leading edge spar side. The wind turbine blade 10 comprises a chord line 38 between the leading edge 18 and the trailing edge 20.

In the following description a reference number followed by the letter A refers to a feature of the first blade shell section 50A and a reference number followed by the letter B refers to a feature of the second blade shell section 50B. A generalized reference number without a subsequent letter, e.g. 50, refers to a feature common for the blade shell sections 50.

The blade shell section 50, e.g. the first blade shell section 50A and/or the second blade shell section 50B, extends in a transverse direction between a first side 56 and a second side 58 and comprises a first sheet 44 forming an inner surface 60 and a second sheet 46 forming an outer surface 62. The first sheet 44 and the second sheet 46 comprises a fibre-reinforced material. Further the sheets 44, 46 comprises a thermoplastic material. The thermoplastic material may be acrylic, polypropylene, PET (Polyethylene terephthalate), or polyamide. The thermoplastic material may also be a thermoplastic material marketed under the name Elium®. The inner surface 60 corresponds to part of the inner surface of the wind turbine blade 10 and the outer surface 62 corresponds to part of the outer surface of the wind turbine blade 10 when assembled. A core 48 comprises thermoplastic material or may be made of a thermoplastic material. In a preferred embodiment, the core 48 made of a foam or honeycomb thermoplastic material is sandwiched between the inner surface 60 and the outer surface 62. The thermoplastic material may comprise one or more of acrylic, polypropylene, PET (Polyethylene terephthalate), polyamide.

The blade shell section 50 comprises a first part 66 being curved, e.g. the outer surface 62 of the first part 66 being curved, such as to follow a curve of a wind turbine blade 10. The first part 66 may correspond to a part of the blade shell section 50 or correspond to the entire blade shell section 50. For example, a part of the blade shell section 50 may be curved, or the entire blade shell section 50 may be curved.

The blade shell section 50 of Figs. 3a and 3b comprises a second part 67 being compressed. The second part 67 may be proximate or at the first side 56. For example, the thickness between the inner surface 60 and outer surface 62 decreases towards the first side 56. The thickness between the inner surface 60 and outer surface 62 may also decrease towards the first end 52 and the second end 54 of Fig. 2.

The blade shell section 50 comprises a third part 68 being compressed. The third part 68 may be proximate or at the second side 58. For example, the thickness between the inner surface 60 and outer surface 62 decreases towards the second side 58.

The blade shell section 50 of Fig. 3b further comprises a fourth part 69 being compressed. The fourth part 69 may be located between the first side 56 and the second side 58. For example, the thickness between the inner surface 60 and outer surface 62 decreases towards a position Pl between the first side 56 and the second side 58.

The second part 67, the third part 68 and/or the fourth part 69 may be compressed by compressing the core 48 of the blade shell section 50 of the respective part. The degree of compression of the core 48 may vary.

Alternatively, the blade shell section 50 of Fig. 3b may be sectionised, e.g. made in sections, and comprise two blade shell sections connected at a position Pl. The sectionised blade shell section 50 may be manufactured by manufacturing a first blade shell section and a second blade shell section and connecting the two blade shell sections by welding or by applying an adhesive at the position Pl.

Figs. 4a-4c are schematic diagrams illustrating an exemplary panel section 43 and an exemplary blade shell section 50, e.g. the blade shell section from Figs. 2-3. In Fig. 4a, a panel section 43 is provided and fed into a machine 76, which manufactures a blade shell section 50 by performing the steps of the method 200 of Fig. 7a. The panel section 43 comprises a first sheet 44, a second sheet 46 and a core 48 sandwiched between the first sheet 44 and the second sheet 46. The provided panel section 43 may be provided as one piece of panel, where the first sheet 44, second sheet 46 and the core 48 are fused together, e.g. by heating, adhesive, welding or other suitable means as illustrated in Fig. 4b. Alternatively, the panel section 43 may be provided as three separate pieces, i.e. the first sheet 44, the second sheet 46 and the core 48 as illustrated in Fig. 4c and fused by heating in the machine 76.

Figs. 5a-5b are schematic diagrams illustrating an exemplary panel section 43, e.g. the blade shell section from Figs. 2-4. The blade shell section 50 of Fig. 5a extends in the transverse direction between a first side 56 and a second side 58 and comprises a first sheet 44 forming an inner surface 60, a second sheet 46 forming an outer surface 62 and a core 48 sandwiched between the first sheet 44 and the second sheet 46. The blade shell section 50 comprises a first part 66 being curved and a second part 67 and a third part 68 being compressed.

Fig. 5b is an enlarged illustration of the second part 67 or the third part 68 of a blade shell section 50, such as the blade shell section 50 of Figs. 2-5. The compressed parts 67, 68 are formed by compressing the core between the first sheet 44 and the second sheet 46. The degree of compression may vary, such that the thickness between the first sheet 44 and the second sheet 46 varies, e.g. decreases, towards the first side 56 and/or the second side 58.

Figs. 6a-6b are schematic diagrams illustrating an exemplary forming station 80, e.g. for manufacturing a blade shell section, such as the blade shell section of Figs. 2-5. The forming station 80 may be machine comprising actuators 70 comprising forming units 72, 74. The forming units may comprise one or more of rollers 72, shoes 74 or clamps (not illustrated) or a combination thereof. The illustrated combination of forming units 72, 74 is one example, but other combinations are also possible. The surface of the forming unit 72, 74 is preferably of low friction such that the panel section may move freely across the forming unit 72, 74. The forming units 72, 74 may come in pairs, such that one forming unit 72, 74 is arranged on each side of the panel section, e.g. one forming unit 72, 74 is configured to contact the first sheet and one forming unit 72, 74 is configured to contact the second sheet.

Fig. 6a illustrates the process of manufacturing a blade shell section 50 for a panel section 43. The panel section 43 comprises a first sheet 44, second sheet 46 and a core 48, which may be provided at separate parts and fused in the forming station 80, or be provided as one piece, where the three parts are already fused together. The panel section 43 is fed into the forming station 80 in a direction according to the arrow DI. The actuators 70 may be computer controlled and programmed to form the panel section 43 to a predetermined shape. The actuators 70 control the forming units 72, 74 to apply pressure to the panel section 43. The blade shell section 50 exits the forming station 80 in a direction according to the arrow D2. The final product of the blade shell section 50 may comprise parts being curved and compressed.

Fig. 6b illustrates the forming station 80 in a position where a panel section may be curved. The actuators 70 and the forming units 72, 74 at the end of the actuators are arranged in a programmed position and apply a pressure such that a panel section may be curved. The illustrated position may also be used to compress a panel section. A panel section 43 (not illustrated) may be fed into the forming station 80 in a direction according to the arrow DI and exit the forming station 80 in a direction according to the arrow D2.

Figs. 7a-7b are block diagrams of an exemplary method 200 for manufacturing a blade shell section for a wind turbine blade and an exemplary method 300 for manufacturing a wind turbine blade.

Fig. 7a illustrates a method 200 for manufacturing a blade shell section for a wind turbine blade, such as the blade shell section 50 of Figs. 2-5. The method 200 comprises providing 202 a panel section. The panel section is a sandwich construction made of a fibre-reinforced thermoplastic material and comprises a core material sandwiched between two fibre-reinforcement sheets. The first fibre-reinforced sheet forms an inner surface and the second fibre-reinforced sheet forms an outer surface. The fibre-reinforcement sheets may comprise a thermoplastic material such as one or more of acrylic, polypropylene, PET (Polyethylene terephthalate), polyamide. The core material may comprise a thermoplastic material such as one or more of acrylic, polypropylene, PET (Polyethylene terephthalate), polyamide.

Providing 202 a panel section may comprise providing 204 a first fibre-reinforcement sheet, providing 206 a second fibre-reinforcement sheet and providing 208 a core material.

The method 200 may comprise heating 212 the panel section such that the thermoplastic material becomes softer and shapable. In the case where the panel section is provided as the first fibrereinforcement sheet, the second fibre-reinforcement sheet and the core material, the three parts may be fused 210 together to form one piece of panel section during heating 212 of the panel section.

The method 200 may comprise cutting 213 the panel section in the longitudinal direction, e.g. the lengthwise direction of the panel section, and/or the transverse direction, e.g. in the direction of the width of the panel section. The panel section may be cut to accommodate the shape of a wind turbine blade where the width of the blade decreases towards the tip end. The cutting may be performed by methods known in the art of cutting thermoplastic panel sections. The method 200 may comprise curving 214 at least the first part of the panel section. Curving 214 may comprise applying 216 pressure to bend the panel section, e.g. by means of controlled actuators with rollers, clamps or shoes.

The method 200 may comprise compressing 218 at least a second part of the panel section. Compressing 218 may comprise applying 220 pressure to the second part such that the thickness between the outer surface and the inner surface of the second part of the blade shell section decreases towards the first side, e.g. by means of controlled actuators with rollers, clamps or shoes.

The method 200 may comprise compressing 218 at least a third part of the panel section. Compressing 218 may comprise applying 220 pressure to the third part such that the thickness between the outer surface and the inner surface of the second part of the blade shell section decreases towards the second side, e.g. by means of controlled actuators with rollers, clamps or shoes.

The method 200 may comprise compressing 218 at least a fourth part of the panel section. Compressing 218 may comprise applying 220 pressure to the fourth part such that the thickness between the outer surface and the inner surface of the fourth part of the blade shell section decreases between the first side and the second side, e.g. by means of controlled actuators with rollers, clamps or shoes. The thickness may decrease towards a first position between the first side and the second side.

The actuators may be computer controlled and set to vary the pressure across the panel in the longitudinal direction and/or the transverse direction.

The method 200 may comprise treating 222 the outer surface with a film, gel coat or a paint.

Fig. 7b illustrates a method 300 for manufacturing a wind turbine blade, such as the wind turbine blade 10 of Figs. 1-3. The method 300 comprises manufacturing 200A a first blade shell section. The first blade shell section may be manufactured according to method 200 of Fig. 7a. The first blade shell section may correspond to the pressure side or suction side blade shell part or part of the pressure side or suction side blade shell part.

The method 300 comprises assembling 304 the first blade shell section with other separately manufactured blade parts to form the wind turbine blade. The other parts may be a leading edge section or a trailing edge section, or a part of a suction side blade shell part or a part of a pressure side blade shell part. The method 300 comprises manufacturing 200B a second blade shell section. The second blade shell section may be manufactured according to method 200 of Fig. 7a. The second blade shell section may correspond to the suction side or pressure side blade shell part or part of the suction side or pressure side blade shell part, whichever is the opposite of the first blade shell section. The method 300 comprises connecting 308 the first blade shell section and the second blade shell section. Connecting 308 the first blade shell section and the second blade shell section may comprise welding 310 at a joint between the first blade shell section and the second blade shell section. The joint may be formed by the first side of the first blade shell section and the second side of the second blade shell section. An intermediate fibre-reinforced thermoplastic part may be applied such that it covers part of the first side of the first blade shell section and part of the second side of the second shell section and welded to the first blade shell section and the second blade shell section. Alternatively, the first blade shell section and the second blade shell section may be connected by applying an adhesive. The adhesive may be applied at an overlapping part of the blade shell sections or an intermediate part covering the first side of the first blade shell section and the second side of the second blade shell section.

The invention has been described with reference to preferred embodiments. However, the scope of the invention is not limited to the illustrated embodiments, and alterations and modifications can be carried out without deviating from the scope of the invention.

LIST OF REFERENCES

2 wind turbine

3 line

4 tower

6 nacelle

8 hub

10 blade

12 blade part

14 blade tip

15 tip end

16 blade root

17 root end

18 leading edge

20 trailing edge

24 first blade shell part (pressure side)

26 second blade shell part (suction side)

28 bond lines/glue joints

30 root region

32 transition region

34 airfoil region

38 chord line

40 shoulder

41 spar cap

42 shear web or spar side

43 panel section

44 first sheet

46 second sheet

48 core

50 blade shell section

50A first blade shell section

50B second blade shell section

50C third blade shell section

50D fourth blade shell section

52 first end

54 second end

56 first side 58 second side

60 inner surface

62 outer surface

64 thickness

66 first part

67 second part

68 third part

69 fourth part

70 actuators

72 rollers

74 shoes

76 machine

80 forming station

DI feed direction

D2 exit direction

200 method for manufacturing blade shell section

202 providing panel section

204 providing first sheet

206 providing second sheet

208 providing core

210 fusing

212 heating

213 cutting

214 curving

216 applying pressure

218 compressing

220 applying pressure

222 treating outer surface

300 method for manufacturing wind turbine blade

200A manufacturing first blade shell section

304 assembling

200B manufacturing second blade shell section

308 connecting blade shell sections 310 welding