Wind turbine blades and wind turbine power generation equipment

Abstract

A wind turbine blade, comprising: a metal receptor including a blade tip of the wind turbine blade; and a blade body portion connected to the metal receptor so as to be positioned on the blade root side of the metal receptor, the blade body portion having a hollow structure and forming an airfoil shape together with the metal receptor in a joining region with the metal receptor in a blade tip region of the wind turbine blade. When viewed in a blade thickness direction of the wind turbine blade, a tangent line of the joining line between the metal receptor and the blade body portion at an intersection point between the joining line and a leading edge of the wind turbine blade is inclined from a chord direction of the wind turbine blade.

Description

Technical Field

[0001] The invention relates to a wind turbine blade and a wind turbine power generating device. Background Art

[0002] Generally, a wind turbine blade is provided with a lightning protection device to reduce damage to the blade body caused by lightning strikes. For example, Patent Document 1 discloses a wind turbine blade having a metal receptor (lightning receiving portion) on the blade tip.

[0003] Reference List

[0004] Patent Literature

[0005] Patent document 1: EP2226497A Summary of the invention

[0006] Issues to be resolved

[0007] When the rotor rotates, the wind turbine blade is hit by foreign matter (e.g., raindrops, dust) in the air, and the collision causes erosion to occur on the leading edge side of the wind turbine blade. In particular, if the foreign matter hits the joint between the blade body part and the receptor, cracks may start from the leading edge side of the joint and develop on the blade body part.

[0008] It is an aim of at least some embodiments of the present invention to inhibit corrosion damage to wind turbine blades.

[0009] Solution to the problem

[0010] (i) A wind turbine blade according to at least one embodiment of the present invention comprises: a metal receptor including a blade tip of the wind turbine blade; and a blade body portion connected to the metal receptor so as to be positioned on the blade root side of the metal receptor, the blade body portion having a hollow structure and forming an airfoil shape together with the metal receptor in a joining region with the metal receptor in a blade tip region of the wind turbine blade. When viewed in a blade thickness direction of the wind turbine blade, a tangent line of a joining line between the metal receptor and the blade body portion at an intersection point between the joining line and a leading edge of the wind turbine blade is inclined from a chord direction of the wind turbine blade.

[0011] With the above-mentioned configuration (i), the joint surface between the metal receptor and the blade body portion having a hollow structure is inclined from the chord direction, and thus the collision angle formed by foreign matter (e.g., raindrops, dust) and the leading edge of the wind turbine blade is different from the tangent direction of the joint surface. Therefore, it is possible to reduce the concentration of impact on the joint portion when foreign matter hits the wind turbine blade, and thus suppress corrosion on the joint surface and corrosion damage to the wind turbine blade.

[0012] In the case where the blade body portion has a "hollow structure", corrosion on the joint surface between the metal receptor and the blade body portion is particularly effectively suppressed. That is, in the case where the blade body portion has a hollow structure, the development of corrosion on the joint surface between the metal receptor and the blade body portion may lead to the formation of a communication path connecting the inside and the outside of the wind turbine blade, which may allow foreign matter to enter the inside (hollow section) of the blade body portion. In this regard, it is technically advantageous to be able to suppress corrosion on the joint surface as described above.

[0013] In this specification, "blade thickness direction" refers to a direction perpendicular to both the blade span direction and the chord direction of the wind turbine blade.

[0014] (ii) In some embodiments, in the above-mentioned configuration (i), when viewed along the blade thickness direction of the wind turbine blade, the joining line can be bent or folded so that the intersection point between the joining line and the trailing edge of the wind turbine blade is positioned closer to the blade tip than the intersection point between the tangent line and the trailing edge of the wind turbine blade.

[0015] With the above configuration (ii), the junction line between the metal receptor and the blade body portion having a hollow structure can have a nonlinear shape from the leading edge to the trailing edge within a range in which the intersection point between the junction line and the trailing edge of the wind turbine blade is closer to the blade tip than the intersection point between the tangent line and the trailing edge of the wind turbine blade. Therefore, it is possible to improve the design flexibility of the shape of the junction between the metal receptor and the blade body portion, and thereby it is possible to select a shape for the metal receptor from a variety of shapes to more appropriately reduce corrosion damage to the wind turbine blade.

[0016] (iii) In some embodiments, in the above configuration (i) or (ii), the tangent line may be inclined from the chord direction so as to be closer to the tip of the blade as it moves away from the leading edge toward the trailing edge of the wind turbine blade.

[0017] With this configuration (three), the metal receptor is arranged on the leading edge side of the joint line, and thereby the joint surface can be protected from collision with foreign matter associated with the rotation of the wind turbine blade, and corrosion on the joint line can be effectively suppressed.

[0018] (iv) In some embodiments, in any one of the above-mentioned constructions (i) to (iii), the length of the metal receptor along the span direction of the blade may be at least 0.1% and not more than 0.9% of the blade length of the wind turbine blade, or at least 50 mm and not more than 700 mm.

[0019] By the above configuration (four), the length of the metal receptor is at least 0.1% of the blade length or at least 50 mm, and thus the metal receptor can exert high lightning protection performance. In addition, when the length of the metal receptor is at most 0.9% of the blade length, or at most 700 mm, the increase in weight of the wind turbine blade associated with the increase in the size of the metal receptor can be suppressed.

[0020] (V) In some embodiments, in any one of the above-mentioned configurations (I) to (IV), the width of the metal receptor along the chord direction may be at least 0.25% and not more than 0.9% of the blade length of the wind turbine blade, or at least 200 mm and not more than 700 mm.

[0021] With the above configuration (V), the width of the metal receptor is at least 0.25% of the blade length, or at least 200 mm, and thus the metal receptor can exert high lightning protection performance. In addition, when the width of the metal receptor is at most 0.9% of the blade length, or at most 700 mm, the increase in weight of the wind turbine blade associated with the increase in the size of the metal receptor can be suppressed.

[0022] (vi) In some embodiments, in any one of the above-mentioned configurations (i) to (v), the joining line may have a curved shape with a radius of curvature not greater than 0.009L, assuming that L is the blade length of the wind turbine blade.

[0023] Utilizing the above-mentioned construction (six), the joining line has a curved shape, which makes it possible to ensure a sufficient inclination angle between the chord direction and the tangent of the joining line at the intersection between the leading edge and the joining line while suppressing the weight of the metal receptor from being concentrated toward the leading edge or toward the trailing edge, thereby effectively suppressing corrosion at the joining line.

[0024] (VII) In some embodiments, in any one of the above configurations (I) to (VI), the wind turbine blade may further include a first anti-corrosion layer covering at least a portion of the outer surface of the blade body portion.

[0025] With the above-mentioned configuration (seven), the first anti-corrosion layer is provided to cover at least a portion of the outer surface of the blade body portion, and thereby corrosion damage to the wind turbine blade can be more effectively suppressed.

[0026] (VIII) In some embodiments, in any one of the above-mentioned structures (I) to (VII), the wind turbine blade may further include a second anti-corrosion layer covering at least a portion of a joining line between the metal receptor and the blade body, which portion is arranged on the leading edge side.

[0027] With the above configuration (eight), the second anti-corrosion layer is additionally provided, and thereby the leading edge side portion of the joining line between the metal receptor and the blade body portion can be covered. Therefore, corrosion on the joining surface can be suppressed even more effectively.

[0028] (ix) In some embodiments, in any one of the above-mentioned configurations (i) to (eight), the wind turbine blade may further include a lightning current transfer portion, which includes at least one of the following components: a metal foil connected to a metal receptor and extending from a connecting section toward a blade root of the wind turbine blade to the metal receptor; or a down conductor.

[0029] By utilizing the above-mentioned configuration (IX), the wind turbine blade may further include a lightning current transfer portion, which includes at least one of a metal foil or a down conductor, and thereby can more reliably exert lightning protection performance while achieving the effect of suppressing corrosion damage to the wind turbine blade described in the above-mentioned configuration (I).

[0030] (J) In some embodiments, in any one of the above configurations (I) to (IX), the blade body portion may include an FRP shell that is connected to the metal receptor while overlapping the metal receptor.

[0031] With the above configuration (ten), the effect of suppressing corrosion damage to the wind turbine blade described in the above configuration (one) can be achieved at the connection section between the metal receptor and the FRP shell having a hollow structure and formed of FRP.

[0032] (XI) In some embodiments, in any one of the above-mentioned configurations (I) to (IX), the metal receptor may have a cavity inside the metal receptor.

[0033] With the above-described configuration (eleven), the metal receptor can have the cavity formed therein, thereby being able to suppress an increase in the weight of the metal receptor while suppressing corrosion on the bonding wire.

[0034] (XII) In some embodiments, in the above configuration (XI), the metal receptor may include a drainage hole connected to the chamber.

[0035] With the above-mentioned configuration (twelve), the metal receptor has a drainage hole communicating with the cavity formed inside the metal receptor, and thereby foreign matter such as raindrops accumulated inside the cavity can be discharged to the outside through the drainage hole, and corrosion damage to the wind turbine blade can be suppressed.

[0036] (thirteen) In some embodiments, in any one of the above-mentioned structures (a) to (eleven), the metal receptor may include: a first part, which forms a pressure surface on one side of the blade tip of the wind turbine blade; and a second part, which forms a suction surface on one side of the blade tip of the wind turbine blade, and the second part is fastened to the first part.

[0037] Utilizing the above-mentioned structure (thirteen), the metal receptor includes: a first part, which forms a pressure surface on one side of the blade tip; and a second part, which forms a suction surface on one side of the blade tip, and thereby is able to promote the assembly and maintenance work of the blade body while achieving the effect of suppressing corrosion damage to the wind turbine blade described in the above-mentioned structure (one).

[0038] (XIV) In some embodiments, in any one of the above configurations (I) to (XIII), the metal receptor may include copper or a copper alloy.

[0039] With the above configuration (fourteen), the metal receptor contains copper or copper alloy having high conductivity, and thereby can more reliably exert lightning protection performance while achieving the effect of suppressing corrosion damage to the wind turbine blade described in the above configuration (one).

[0040] (15) A wind turbine power generating device according to at least some embodiments of the present invention may include a wind turbine blade according to any one of the above configurations (1) to (14).

[0041] With the above-described configuration (fifteen), it is possible to provide a wind turbine power generating equipment including a wind turbine blade, whereby corrosion at the joint surface can be effectively suppressed.

[0042] Beneficial effects

[0043] According to at least one embodiment of the present invention, erosion of wind turbine blades can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a diagram showing a configuration example of a wind turbine power generation equipment.

[0045] Figure 2 is a perspective view of a wind turbine blade according to an embodiment.

[0046] Figure 3A and Figure 3B Along Figure 2 A cross-sectional view taken along lines AA and BB.

[0047] Figure 4 is a plan view of a tip side of a wind turbine blade according to an embodiment.

[0048] Figure 5 is a diagram of a blade tip portion of a wind turbine blade according to an embodiment.

[0049] Figure 6 is a diagram of a blade tip portion of a wind turbine blade according to another embodiment.

[0050] Figure 7 is a diagram of a blade tip portion of a wind turbine blade according to another embodiment.

[0051] Figure 8 is a diagram of a blade tip portion of a wind turbine blade according to another embodiment.

[0052] Fig. 9 is a diagram of a blade tip portion of a wind turbine blade according to another embodiment.

[0053] Fig.10 is a diagram of a blade tip portion of a wind turbine blade according to another embodiment.

[0054] Fig.11 is a plan view of a resist layer in some embodiments.

[0055] Fig.12 is a diagram showing another configuration example of a wind turbine power generating equipment.

[0056] Fig.13 is a cross-sectional view of a tip side of a wind turbine blade according to an embodiment. DETAILED DESCRIPTION

[0057] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in the embodiments should be interpreted as merely illustrative and are not intended to limit the scope of the present invention.

[0058] For example, expressions of relative or absolute arrangement such as "in a direction", "along a direction", "parallel", "orthogonal", "centered", "concentric" and "coaxial" should not be interpreted as indicating only an arrangement in a strict literal sense, but also include a state in which the arrangement is relatively shifted by a certain tolerance, or a certain angle or distance, thereby being able to achieve the same function.

[0059] For example, expressions of equivalent states such as “same,” “equal,” and “uniform” should not be interpreted as indicating only a state in which features are strictly equivalent, but also include a state in which there are tolerances or differences that can still achieve the same function.

[0060] Furthermore, for example, expressions of shapes such as a rectangle or a cylinder should not be interpreted as only strict geometric shapes but also include shapes having uneven or chamfered corners within the range in which the same effect can be achieved.

[0061] On the other hand, expressions such as “comprising,” “including,” “having,” “containing,” and “consisting of” are not intended to exclude other components.

[0062] Figure 1 is a schematic diagram of a configuration example of a wind turbine power generation device according to an embodiment. Figure 2 is a perspective view of a wind turbine blade according to an embodiment. Figure 3A and Figure 3B Along Figure 2 A cross-sectional view taken along lines AA and BB. Figure 4 is a plan view of a tip side of a wind turbine blade according to an embodiment.

[0063] like Figure 1 As depicted in FIG. 1 , according to at least one embodiment of the present invention, a wind turbine power generating device (hereinafter referred to as a wind turbine) 1 includes at least one wind turbine blade 2, a hub 3 on which the wind turbine blade 2 is mounted, a nacelle 4 supporting a rotor including the wind turbine blade 2 and the hub 3, and a tower 5 rotatably supporting the nacelle 4. The rotation of the rotor is input to a generator (not depicted), and electricity is generated by the generator.

[0064] If the wind turbine power generating device is an offshore type, the tower 5 is arranged on the ocean, and if the wind turbine power generating device is an onshore type, the tower 5 is arranged on a foundation on land.

[0065] like Figure 2 As depicted in , the wind turbine blade 2 according to the embodiment includes a blade body portion 20 extending from a blade root portion 2A toward a blade tip portion 2B, and a metal receptor 50 including the blade tip portion 2B of the wind turbine blade 2 .

[0066] like Figure 2 As depicted in FIG. 1 , the blade body portion 20 includes: a blade root portion 2A, which is attached to the hub 3 of the wind turbine 1; a blade tip portion 2B, which is located farthest from the hub 3; and a wing portion 2C (blade center portion) extending between the blade root portion 2A and the blade tip portion 2B in the blade span direction. In addition, the blade body portion 20 has a leading edge 21 and a trailing edge 23 extending from the blade root portion 2A to the blade tip portion 2B. The profile of the blade body portion 20 is defined by a suction surface 25 and a pressure surface 27 defined across the leading edge 21 and the trailing edge 23 (see FIG. 1 ). Figure 2 and 3).

[0067] In this specification, the "blade span direction" refers to the direction connecting the blade root 2A and the blade tip 2B, and the "chord direction (blade chord direction)" refers to the direction along the line (chord) connecting the leading edge 21 and the trailing edge 23 of the blade body 20. In addition, the "blade thickness direction (flap direction)" refers to the direction substantially orthogonal to the chord direction connecting the leading edge 21 and the trailing edge 23, that is, the direction connecting the suction side and the pressure side of the blade body 20 (see Figure 2 3). In addition, the “blade root” refers to a cylindrical portion of the wind turbine blade 2 having a substantially circular cross-section, extending in a blade span direction range of, for example, 5 m from an end surface on one side of the blade root 2A of the blade body portion 20 of the wind turbine blade 2 (typically ranging from 1 m to 3 m from the end surface).

[0068] In some embodiments, the blade body portion 20 is at least partially made of fiber reinforced plastic (FRP). Figure 4 As depicted in FIG, the wind turbine blade 2 may include a metal foil 32 extending from a joint 10 between a metal receptor 50 and an end of a blade body portion 20 toward a blade root 2A along a blade span direction. The metal foil 32 may be configured to guide a lightning current from the metal receptor 50 toward the blade root 2A, and may have a function as a down conductor. In an embodiment, the metal foil 32 is electrically connected to another down conductor passing through the blade root 2A, the hub 3, the nacelle 4, and the tower 5. When the metal receptor 50 receives lightning, the metal foil 32 may guide the lightning current from the metal receptor 50 to a ground terminal mounted to the tower 5 via the other down conductor.

[0069] like Figure 2 As depicted in FIG. 2 , in some embodiments, the blade body portion 20 is connected to the metal receptor 50 while being located on a side of the metal receptor 50 closer to the blade root portion 2A. In some embodiments, the blade body portion 20 has a hollow structure that forms an airfoil shape in a blade tip region of the wind turbine blade 2 together with the metal receptor 50 in a joining region between the blade body portion 20 and the metal receptor 50.

[0070] Specifically, Figure 3A As shown in , at the blade root 2A in the embodiment, the wind turbine blade 2 includes an inner blade root reinforcement member 22, an airfoil shaping member 24 having a spar cap 26, an insulating layer 28, an outer blade root reinforcement member 30, a metal foil 32 and a protective layer 34, and these components are arranged in this order from the inside to the outside in the thickness direction. In addition, in the embodiment, as Figure 3BAs shown in FIG. 2 , at the wing portion 2C, the wind turbine blade 2 includes an airfoil forming member 24 having a spar cap 26 , an insulating layer 28 , a metal foil 32 , and a protective layer 34 , which are arranged in this order from the inside to the outside in the thickness direction.

[0071] exist Figure 3A and Figure 3B , the thickness and size of each component are depicted in a manner different from actual measurements of the wind turbine blade to simplify the description.

[0072] In some embodiments, the blade body portion 20 may be configured such that the suction surface 25 and the pressure surface 27 are joined to each other to form a single piece along an edge portion of each of the leading edge 21 and the trailing edge 23, such as Figure 2 , Figure 3A and Figure 3B Depicted. In some embodiments, in the wind turbine blade 2, the suction surface 25 and the pressure surface 27 may be coupled to each other via at least one shear web 36 (beam member) in the blade span direction at the respective inner surface sides. The shear web 36 may be arranged continuously from the blade root portion 2A to near the end of the blade body portion 20. In the case where the shear web 36 is also provided on the tip side of the blade body portion 20, the load increased by the metal receptor 50 can be supported by the shear web 36. The end of the blade body portion 20 is an end of the blade body portion 20 on one side of the blade tip portion 2B, which portion has the metal receptor 50 connected thereto.

[0073] In some embodiments, the insulating layer 28 is interposed between the spar cap 26 and the metal foil 32, and the insulating layer 28 insulates the spar cap 26 from the metal foil 32. Therefore, when the metal receptor 50 receives lightning, it is possible to prevent a strong lightning current from traveling from the metal foil 32 to the spar cap 26 and damaging the spar cap 26.

[0074] As described above, the metal foil 32 extends from the joint 10 between the metal receptor 50 and the end of the blade body portion 20 toward the blade root portion 2A along the blade span direction. For example, the metal foil 32 may have a sheet shape or a mesh shape and may be made of copper or a copper alloy.

[0075] like Figures 4 to 11 As depicted in , in some embodiments, when the wind turbine blade 2 is viewed in the blade thickness direction, a tangent line 72 to a joining line 70 between the metal receptor 50 and the blade body portion 20 at an intersection point P between the joining line 70 and the leading edge 21 side of the wind turbine blade 2 is inclined (at an inclination angle θ) from the chord direction of the wind turbine blade 2.

[0076] With the above configuration, the joint surface between the metal receptor 50 and the blade body portion 20 having a hollow structure is inclined from the chord direction, and thereby the collision angle formed by the foreign matter F (e.g., raindrops, dust) and the leading edge 21 of the wind turbine blade 2 is different from the tangent direction of the joint surface. Therefore, the concentration of the impact on the joint portion when the foreign matter collides with the wind turbine blade 2 can be reduced, and thereby corrosion on the joint surface and corrosion damage to the wind turbine blade 2 are suppressed. The vertical collision between the foreign matter F in the air and the leading edge 21 of the joint line 70 of the wind turbine blade 2 can be avoided, and thereby the concentration of the impact on the joint portion 10 when the foreign matter F collides with the wind turbine blade 2 can be reduced, and the corrosion damage to the wind turbine blade 2 can be reduced.

[0077] Suppressing corrosion on the joint surface between the metal receptor 50 and the blade body portion 20 as described above is effective, especially in the case where the blade body portion 20 has a "hollow structure", as in some embodiments. That is, in the case where the blade body portion 20 has a hollow structure, the development of corrosion on the joint surface between the metal receptor 50 and the blade body portion 20 may lead to the formation of a communication path connecting the inside and the outside of the wind turbine blade 2, which may allow foreign matter to pass through and enter the inside (hollow section) of the blade body portion 20, and thus, as described above, it is technically advantageous to be able to suppress corrosion on the joint surface.

[0078] In some embodiments, for example, Figure 5 As depicted in FIG. 1 , the joint line 70 may have a straight line shape such that when viewed in the blade thickness direction of the wind turbine blade 2, the intersection point Q between the joint line 70 and the trailing edge 23 of the wind turbine blade 2 and the intersection point R between the tangent line 72 and the trailing edge 23 of the wind turbine blade 2 are at the same position. In some embodiments, for example, Figure 6 As depicted in , the joint line 70 may have a curved shape so that when viewed in the blade thickness direction of the wind turbine blade 2, the intersection point Q between the joint line 70 and the trailing edge 23 of the wind turbine blade 2 is located closer to the blade tip portion 2B than the intersection point R between the tangent line 72 and the trailing edge 23 of the wind turbine blade 2. In addition, in some embodiments, for example, Figure 7 As depicted in , the joint line 70 may have a curved shape such that an intersection point Q between the joint line 70 and the trailing edge 23 of the wind turbine blade 2 is located closer to the blade tip portion 2B than an intersection point R between the tangent line 72 and the trailing edge 23 of the wind turbine blade 2 .

[0079] With the above-described configuration, the joint line 70 between the metal receptor 50 and the blade body portion 20 having a hollow structure can have a nonlinear shape from the leading edge 21 to the trailing edge 23 within a range in which the intersection point Q between the joint line 70 and the trailing edge 23 of the wind turbine blade 2 is closer to the blade tip portion 2B than the intersection point R between the tangent line 72 and the trailing edge 23 of the wind turbine blade 2. Therefore, the design flexibility of the shape of the joint 10 between the metal receptor 50 and the blade body portion 20 can be improved, and thus the shape for the metal receptor 50 can be selected from various shapes to more appropriately reduce the corrosion damage to the wind turbine blade 2 using the metal receptor 50.

[0080] exist Figures 5 to 7 In the exemplary embodiment depicted in , any one of the intersection points P between the junction line 70 and the leading edge 21 or the intersection point Q between the junction line 70 and the trailing edge 23 may be positioned closer to the blade tip portion 2B. In other words, the intersection point P may be arranged closer to the blade tip portion 2B than the intersection point Q, or the intersection point Q may be arranged closer to the blade tip portion 2B than the intersection point P. In addition, the intersection point R between the tangent line 72 and the trailing edge 23 may be arranged closer to the blade root 2A than a chord passing through the intersection point P, or may be closer to the tip portion 2B than the chord.

[0081] In some embodiments, Figure 4 , Fig. 9 or Fig.10 As depicted in FIG. 1 , the tangent line 72 may be inclined from the chord direction so that the tangent line 72 extends closer to the blade tip portion 2B as it moves away from the leading edge 21 toward the trailing edge 23 of the wind turbine blade 2. With this configuration, the metal receptor 50 is arranged on the leading edge 21 side of the joint line 70, and thus corrosion on the joint line 70 can be effectively suppressed.

[0082] In some embodiments, the length L1 of the metal receptor 50 along the blade span direction may be at least 0.1% and not more than 0.9% (0.001L≤L1≤0.009L) of the blade length L of the wind turbine blade 2, or may be at least 50 mm and not more than 700 mm (50 mm≤L1≤700 mm) (see Figure 2 and Figure 4 ). Therefore, when the length of the metal receptor 50 is at least 0.1% of the blade length or at least 50 mm, the metal receptor 50 can exert high lightning protection performance. In addition, when the length of the metal receptor 50 is not more than 0.9% of the blade length or 700 mm, the weight increase of the wind turbine blade 2 associated with the increase in the size of the metal receptor 50 can be suppressed.

[0083] In some embodiments, the width W1 of the metal receptor 50 along the chord direction may be at least 0.25% and not more than 0.9% of the blade length L of the wind turbine blade 2 (0.0025L≤W1≤0.009L), or may be at least 200 mm and not more than 700 mm (200 mm≤L1≤700 mm) (see Figure 2 and Figure 4 ). Therefore, when the width of the metal receptor 50 is at least 0.25% of the blade length or at least 200 mm, the metal receptor 50 can exert high lightning protection performance. In addition, when the width of the metal receptor 50 is not more than 0.9% of the blade length or 700 mm, the increase in weight of the wind turbine blade 2 associated with the increase in the size of the metal receptor 50 can be suppressed.

[0084] In some embodiments, assuming that L is the blade length of the wind turbine blade 2, the joint line 70 may have a curved shape with a radius of curvature R1 not greater than 0.009L (R1 ≤ 0.009L) (see Figure 2 , Figure 8 and Fig. 9 With this configuration, the joint line 70 has a curved shape, which makes it possible to suppress the weight concentration of the metal receptor 50 toward the leading edge 21 or toward the trailing edge 23, and to ensure an inclination angle between the chord direction and a tangent line 72 at an intersection point P between the leading edge 21 and the joint line 70, thereby effectively suppressing corrosion at the joint line 70.

[0085] like Fig.11 As depicted in , in some embodiments, the wind turbine blade 2 may further include a first anti-corrosion layer 80 covering at least a portion of the outer surface of the blade body portion 20 .

[0086] In some embodiments, the first anti-corrosion layer 80 is a protective material having anti-wear (anti-corrosion) properties, and may be embodied as a tape, a paint, a coating, etc. The first anti-corrosion layer 80 is applied or attached to the surface of the blade body portion 20 to protect the blade body portion 20 from colliding with foreign matter F in the air. In some embodiments, the first anti-corrosion layer 80 may be a polyurethane coating material (e.g., 3M wind turbine blade protective coating W4600 of 3M (trademark), polyurethane coating material of BASF), or a tape having such a polyurethane coating material applied thereto.

[0087] With this configuration, the first anti-corrosion layer 80 is further provided to cover at least a portion of the outer surface of the blade body portion 20 , and thereby corrosion damage to the wind turbine blade 2 can be more effectively reduced.

[0088] like Fig.11As depicted in FIG. 1 , in some embodiments, the wind turbine blade 2 may further include a second anti-corrosion layer 82 that covers at least a portion of the joining line 70 between the metal receptor 50 and the blade body portion 20, the portion being arranged on the leading edge 21 side. In the case where the second anti-corrosion layer 82 is additionally provided, the portion of the joining line 70 between the metal receptor 50 and the blade body portion 20 on the leading edge 21 side can be covered. Therefore, corrosion on the joining line 70 can be suppressed even more effectively.

[0089] like Fig.12 As depicted in , in some embodiments, the wind turbine blade 2 may further include a lightning current transmission portion 90 including at least one of the following: a metal foil 32 connected to the metal receptor 50 and extending from the connection section toward the blade root 2A of the wind turbine blade 2 to the metal receptor 50; or a down conductor 8. With this configuration, a lightning current transmission portion 90 including at least one of the metal foil 32 or the down conductor 8 is provided, and thereby the lightning protection performance can be more reliably exerted while achieving the above-mentioned effect of suppressing corrosion damage to the wind turbine blade 2.

[0090] Now refer to Fig.13 A configuration example of the metal receptor 50 is described. Fig.13 is a cross-sectional view of a tip side of a wind turbine blade according to an embodiment.

[0091] A first recess 54A, 54B and a second recess 56A, 56B are formed on the outer surface of the end of the metal receptor 50. The first recess 54A, 54B and the second recess 56A, 56B are arranged adjacent to each other via steps 55A, 55B in the blade span direction. The first recess 54A, 54B is arranged closer to the blade root 2A, and the second recess 56A, 56B is arranged closer to the blade tip 2B. The first recess 54A, 54B is formed shallower than the second recess 56A, 56B. In addition, bolt holes 57A1, 57B1 are formed in the first recess, and bolt holes 57A2, 57B2 are formed in the second recess. Although in the present configuration, the first recess 54A, 54B is arranged adjacent to the second recess 56A, 56B in the blade span direction, the configuration of the recess is not limited thereto. For example, the first recessed portions 54A, 54B and the second recessed portions 56A, 56B may be arranged adjacent to each other in the blade width direction.

[0092] In some embodiments, the metal receptor 50 may be formed of copper or a copper alloy. Therefore, in the case of the metal receptor 50 including copper or a copper alloy having high conductivity, lightning protection performance can be more reliably exerted while achieving the above-mentioned effect of suppressing corrosion damage to the wind turbine blade 2.

[0093] In some embodiments, the blade body portion 20 may include an FRP shell 29 connected to the metal receptor 50 in a state of overlapping the metal receptor 50. For example, Fig.13 As depicted in FIG. 1 , at the joint 10 between the blade body portion 20 and the metal receptor 50, the fiber reinforced plastic 24A (FRP) is fastened to the metal receptor 50 in a state where the fiber reinforced plastic 24A and the metal receptor 50 at least overlap, and the end of the metal foil 32 is electrically connected to the metal receptor 50. In addition, as Fig.13 As depicted in FIG. 1 , the metal foil 32 is interposed between the first metal plate 40 and the second metal plate 42 at the joint 10 . The first metal plate 40 and the second metal plate 42 may extend from the joint 10 to a middle position of the blade body portion 20 .

[0094] Furthermore, the first recesses 54A, 54B are engaged with the fiber reinforced plastic 24A, the second metal plate 42, the metal foil 32, and the first metal plate 40 forming the end of the blade body portion 20, and these components are fastened together using the bolts 46, which are screwed into the bolt holes 57A1, 57A2. Therefore, the blade body portion 20 and the metal receptor 50 are connected. Since the fiber reinforced plastic 24A and the metal receptor 50 are fastened to each other in a state where they at least overlap each other, a larger contact area can be achieved between the fiber reinforced plastic 24A and the metal receptor 50 at the joint 10, which makes it possible to maintain a high connection strength, which can withstand, for example, the bending moment of the wind turbine blade 2 generated by the wind load received by the wind turbine blade 2. Furthermore, the first recesses 54A, 54B and the fiber reinforced plastic 24A are in surface contact with each other, which makes it possible to ensure a high connection strength between the blade body portion 20 and the metal receptor 50.

[0095] In addition, the second recesses 56A, 56B are engaged with the second metal plate 42, the metal foil 32, and the first metal plate 40, and these components are fastened together using bolts 48, which are screwed into the bolt holes 57A2, 57B2. Therefore, the metal foil 32 is connected to the metal receptor 50 via the second metal plate 42. Thus, the metal foil 32 and the metal receptor 50 used as a down conductor are electrically connected. Since the metal foil 32 is fastened while overlapping with the metal receptor 50 via the second metal plate 42, the metal foil 32 and the metal receptor 50 are electrically connected to each other via a large electrical connection area, and thus the lightning current received by the metal receptor 50 can be smoothly flowed to the metal foil 32. In addition, the second recesses 56A, 56B and the second metal plate 42 are in surface contact with each other, which makes it possible to ensure the electrical connection between the metal foil 32 and the metal receptor 50 via the second metal plate 42. With the above configuration, as described in the above embodiment, the effect of suppressing corrosion damage to the wind turbine blade 2 can be achieved at the connection section between the metal receptor 50 and the FRP shell 29 of the hollow structure formed of the fiber reinforced plastic 24A.

[0096] like Fig.13 As depicted in , in some embodiments, the metal receptor 50 may include: a first portion 52A, which forms the pressure surface 27 on the side of the blade tip portion 2B of the wind turbine blade 2; and a second portion 52B, which forms the suction surface 25 on the side of the blade tip portion 2B of the wind turbine blade 2, and the second portion 52B is fastened to the first portion 52A. In an embodiment, the first portion 52A of the metal receptor 50 may have a shape substantially symmetrical to the second portion 52B. The first portion 52A has a docking surface 53A that conforms to a docking surface 53B of the second portion 52B, and the first portion 52A is fastened to the second portion 52B. A plurality of bolt holes (not depicted) are formed on the docking surface 53A of the first portion 52A, and a plurality of bolt holes (not depicted) are formed on the docking surface 53B of the second portion 52B in positions corresponding to those bolt holes on the docking surface 53A. Therefore, the first portion 52A and the second portion 52B are bolted while the docking surfaces 53A, 53B conform to each other. As described above, in the case where the metal receptor 50 has a bisected shape, for example, the first metal plate 40, the second metal plate 42, and the metal foil 32 can be easily attached to the metal receptor 50. With this configuration, the metal receptor 50 includes the first portion 52A that forms the pressure surface 27 on the blade tip portion 2B side, and the second portion 52B that forms the suction surface 25 on the blade tip portion 2B side, and thereby, as described in the above-described embodiment, it is possible to facilitate the assembly and maintenance work of the blade body portion 20 while achieving the effect of suppressing corrosion damage to the wind turbine blade 2.

[0097] like Fig.13As depicted in FIG. 1 , in some embodiments, the metal receptor 50 may have the cavity 51 formed therein. With the above configuration, the metal receptor 50 has the cavity 51 formed therein, and thereby it is possible to suppress an increase in the weight of the metal receptor 50 while suppressing corrosion on the bonding wire 70.

[0098] For example Fig.13 As depicted in FIG. 1 , in some embodiments, the metal receptor 50 may have a cavity 51 formed therein and a drain hole 59 communicating with the cavity 51. With this configuration, the metal receptor 50 has the drain hole 59 communicating with the cavity 51 formed inside the metal receptor 50, and thereby foreign matter F such as raindrops accumulated inside the cavity 51 can be discharged to the outside through the drain hole 59, and thus corrosion damage to the wind turbine blade 2 can be effectively suppressed.

[0099] like Fig.13 , for example, when assembled with the first part 52A, the second part 52B has a chamber (recess) 51, which combines with the recess of the first part 52A to form an empty section in the metal receptor 50. In addition, a drain hole 59 may be provided to communicate with the chamber 51. The drain hole 59 is arranged on the top end of the metal receptor 50. If the chamber 51 is divided into a plurality of chambers by the docking surface 53B, a groove may be formed on the docking surface 53B so that the plurality of chambers 51 communicate with each other.

[0100] With this configuration, foreign matter F such as raindrops gathered inside the metal receptor 50 can be smoothly discharged to the outside from the empty section formed by the chamber 51 through the drainage hole 59 .

[0101] Furthermore, the first portion 52A may have the same configuration as the second portion 52B.

[0102] As described above, according to the above-described embodiment, it is possible to provide the wind turbine 1 having the wind turbine blade 2 , whereby corrosion on the joint line 70 can be effectively suppressed.

[0103] Although the embodiments of the present invention are described above in detail, the present invention is not limited thereto, and various modifications and variations may be implemented.

[0104] Description of Reference Numerals

[0105] 1 Wind turbine (wind turbine power generation equipment)

[0106] 2 Wind turbine blades

[0107] 2A Blade root

[0108] 2B Blade tip

[0109] 2C Wing

[0110] 3 Hub

[0111] 4 Cabins

[0112] 5 Tower

[0113] 8 Downlead

[0114] 10 Joint

[0115] 20 Blade body

[0116] 21 Front Edge

[0117] 22 Internal blade root reinforcement

[0118] 23 trailing edge

[0119] 24 Airfoil forming components

[0120] 24A fiber reinforced plastic

[0121] 25 Suction surface

[0122] 26 Beam cap

[0123] 27 Pressure surface

[0124] 28 Insulation layer

[0125] 29FRP shell

[0126] 30 External blade root reinforcement

[0127] 32 metal foil

[0128] 34 Protective layer

[0129] 36 Shear web

[0130] 40 First Metal Plate

[0131] 42 Second Metal Plate

[0132] 46, 48 bolts

[0133] 50 Metal Receptors

[0134] 51 Chamber

[0135] 52A Part 1

[0136] 52B Part 2

[0137] 53A, 53B docking surface

[0138] 54A, 54B first recess

[0139] Steps 55A, 55B

[0140] 56A, 56B second recess

[0141] 57A1, 57A2, 57B1, 57B2 bolt holes

[0142] 59 Drainage hole

[0143] 70 Bonding wire

[0144] 72 Tangent

[0145] 80 First anti-etching layer

[0146] 82 second resist layer

[0147] 90 Lightning current transmission section

[0148] F Foreign matter

[0149] P, Q, R intersection

Claims

1. A wind turbine blade (2), comprising: a metal receptor (50), the metal receptor (50) forming a blade tip of the wind turbine blade (2); as well as A blade body portion (20), the blade body portion (20) being positioned on the blade root side of the metal receptor (50) and comprising a tip end portion connected to the metal receptor, wherein the blade body portion (20) comprises a blade root portion (2A), the blade root portion (2A) being attached to a hub (3) of a wind turbine (1); a blade tip portion (2B), the blade tip portion (2B) being positioned farthest from the hub (3); and a blade center portion (2C), the blade center portion (2C) extending between the blade root portion (2A) and the blade tip portion (2B) in the blade span direction, wherein the blade body portion (20) has a leading edge (21) and a trailing edge (23), the leading edge (21) and the trailing edge (23) extending from the blade root portion (2A) to the blade tip portion (2B), and a blade chord direction is a direction along a chord connecting the leading edge (21) and the trailing edge (23), The blade body (20) has a hollow structure, and the blade body (20) forms an airfoil shape in a blade tip region of the wind turbine blade (2) together with the metal receptor (50) in a joining region with the metal receptor (50), When viewed in the blade thickness direction of the wind turbine blade (2) perpendicular to both the span direction and the chord direction, a tangent line (72) of a joining line (70) between the metal receptor (50) and the blade body (20) at an intersection point P between the joining line (70) and the leading edge (21) of the wind turbine blade (2) is inclined from the chord direction of the wind turbine blade (2) so as to be closer to the blade tip as it moves away from the leading edge (21) toward the trailing edge (23) of the wind turbine blade (2), so that a joining surface between the metal receptor and the blade body having a hollow structure is inclined from the chord direction, thereby making a collision angle formed by a foreign object with the leading edge of the wind turbine blade different from a tangent direction of the joining surface, thereby reducing the concentration of impact on the joining portion when the foreign object hits the wind turbine blade, and thereby suppressing corrosion on the joining surface and corrosion damage to the wind turbine blade.

2. The wind turbine blade (2) according to claim 1, in, When viewed in the blade thickness direction of the wind turbine blade (2), the joint line (70) is bent or curved so that an intersection point Q between the joint line (70) and the trailing edge (23) of the wind turbine blade (2) is located closer to the blade tip than an intersection point R between the tangent line (72) and the trailing edge (23) of the wind turbine blade (2).

3. A wind turbine blade (2) according to claim 1 or 2, in, The length of the metal receptor (50) along the blade span direction is at least 0.1% and not more than 0.9% of the blade length of the wind turbine blade (2), or at least 50 mm and not more than 700 mm.

4. A wind turbine blade (2) according to claim 1 or 2, in, The width of the metal receptor (50) along the chord direction is at least 0.25% and not more than 0.9% of the blade length of the wind turbine blade (2), or at least 200 mm and not more than 700 mm.

5. A wind turbine blade (2) according to claim 1 or 2, in, The joining line (70) has a curved shape, wherein, assuming that L is the blade length of the wind turbine blade (2), the radius of curvature is not greater than 0.009L.

6. The wind turbine blade (2) according to claim 1 or 2, further comprising a first anti-corrosion layer (80), the first anti-corrosion layer covering at least a portion of the outer surface of the blade body portion (20).

7. The wind turbine blade (2) according to claim 1 or 2, further comprising a second anti-corrosion layer (82), which covers at least a portion of the joint line (70) between the metal receptor (50) and the blade body part (20), the portion being arranged on the leading edge (21) side.

8. The wind turbine blade (2) according to claim 1 or 2, further comprising a lightning current transmission part (90), the lightning current transmission part comprising at least one of the following components: a metal foil (32) connected to the metal receptor (50) and extending from a connection section of the metal receptor (50) toward a blade root (2A) of the wind turbine blade (2); or a down conductor (8).

9. A wind turbine blade (2) according to claim 1 or 2, in, The blade body portion (20) includes a fiber reinforced plastic shell (29) which is connected to the metal receptor (50) while overlapping the metal receptor (50).

10. A wind turbine blade (2) according to claim 1 or 2, in, The metal receptor (50) has a cavity (51) inside the metal receptor (50).

11. A wind turbine blade (2) according to claim 10, in, The metal receptor (50) includes a drainage hole (59) which is in communication with the chamber (51).

12. A wind turbine blade (2) according to claim 1 or 2, in, The metal receptor (50) comprises: a first portion (52A) forming a pressure surface (27) on a blade tip side of the wind turbine blade (2); and A second part (52B), which forms a suction surface (25) on the blade tip side of the wind turbine blade (2), is fastened to the first part (52A).

13. A wind turbine blade (2) according to claim 1 or 2, in, The metal receptor (50) comprises copper or a copper alloy.

14. A wind turbine power generating device comprising a wind turbine blade (2) according to any one of claims 1 to 13.

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