Turbine blade for a wind turbine

Abstract

Turbine blade for a wind turbine (1), comprising a blade body (6) having a leading edge (7), characterized in that the blade body (6) is provided with a deformation device (8) covering the leading edge (7) and extending at least partially along the leading edge (7), the deformation device (8) comprising a housing (9) fixed to the blade body (6), the housing (9) being movable by means of actuating means (13) between a first position close to the leading edge (7) and a second position away from the leading edge (7).

Description

Technical Field

[0001] The present invention relates to turbine blades for wind turbines, the turbine blades comprising a blade body having a leading edge. Background Technology

[0002] As is well known, wind turbines are used to generate electricity. A turbine includes a tower, a nacelle atop the tower, and a generator coupled to a hub. Typically, three turbine blades, also commonly referred to as rotor blades, are attached to the hub. The turbine or rotor blades interact with blowing wind to rotate the hub and drive the generator. Such a setup and function of a wind turbine are well known.

[0003] For example, see EP 1 613 860 B1. Turbine blades with variable airfoil geometry are also known for controlling aerodynamic forces acting on the blade, such as increasing lift generated by blade sections. To change the geometry, corresponding devices are typically provided at the trailing edge of the blade in the form of flaps or the like. These devices can be attachments arranged on the blade or the corresponding trailing edge, or they can be integrated into the blade body or its corresponding trailing edge, as shown in EP 1 613 860 B1.

[0004] Furthermore, altering the shape or corresponding cross-sectional geometry of the airfoil at the leading edge can affect aerodynamic parameters, such as balancing lift distribution and reducing the magnitude of moment imbalance. EP 1 613 860 B1 discloses a mechanism for changing the shape of the leading edge of a blade. The blade includes a blade body with an airfoil shape having a leading edge region, which is part of the blade body. The skin of the leading edge region, and thus the corresponding skin of the blade body region, is made of rubber or the like. One or more pieces of smart material are integrated within the skin in this region, which can be actively controlled to move the leading edge so that it bends upward or downward toward the suction side surface or the pressure side surface, respectively. The corresponding smart material pieces are arranged in the blade body, and correspondingly in the leading edge skin at the upper or suction side surface and the lower or pressure side surface. Depending on which smart material piece is controlled to extend, the leading edge of the blade body bends upward or downward.

[0005] While this embodiment allows control over the airfoil geometry of the blade and thus its aerodynamic characteristics, the arrangement of the blade or corresponding blade body is highly complex. This is because the known system requires constructing the leading edge with a sufficiently flexible, bendable material and integrating corresponding smart material sheets into the blade body skin and the corresponding actuators. Additional structural measures are also needed to maintain the mechanical parameters of the blade, namely, the stiffness and rigidity of the corresponding blade. Summary of the Invention

[0006] One object of the present invention is to provide an improved turbine blade.

[0007] To achieve this objective, a turbine blade for a wind turbine, comprising a blade body having a leading edge, is characterized in that the blade body is provided with a form changing device that covers the leading edge and extends at least partially along the leading edge, the form changing device comprising a housing fixed to the blade body, the housing being movable by an actuation device between a first position near the leading edge and a second position away from the leading edge.

[0008] The turbine blade of the present invention comprises a blade body having a trailing edge and a leading edge, which, as is known, is manufactured, for example, as a fiber composite portion made of resin-embedded fiber pads to provide corresponding mechanical properties of the blade body in the blade body skin or casing. Furthermore, due to this arrangement, the leading edge is also extremely rigid and stiff. Therefore, the casing of the blade body itself is not flexible or variable in its shape or geometry. To allow for alteration or adjustment of the airfoil geometry at the leading edge region, the present invention provides a deformation device or shape-changing device attached to the blade body, which covers the leading edge of the blade body and extends at least partially along the length of the leading edge. Thus, the deformation device is an add-on that is fixed to the blade body having a generally configured, rounded leading edge, as is known.

[0009] As described, the deformable device covers the leading edge but is used to change the overall geometry, and thereby alter the aerodynamic properties of the blade in the leading edge region. To change the geometry, the deformable device includes a housing fixed to the blade body. This housing covers the leading edge of the blade body. The housing is coupled to an actuator adapted to move the housing relative to the blade body or the corresponding leading edge of the blade body covered by the housing. In a first position, the housing is positioned close to the leading edge and is correspondingly fitted to it. The housing can be moved from this first position and away from the leading edge to a second position, in which it is spaced from the leading edge, and a certain amount of free space is provided between the leading edge and the housing. By moving the housing relative to the blade body or the corresponding leading edge, the overall geometry can be significantly altered, and thus the aerodynamic properties can be changed. Depending on the current conditions, for example, a positive camber can be generated, thereby producing increased lift, and thus increasing the power generation of the wind turbine at wind speeds below a specific rated wind speed. Alternatively, a negative camber can be generated, thereby reducing the lift produced by the blades and thus reducing the load on the turbine, which can be beneficial under certain wind conditions, especially near the shoulder of the power curve, a design driver for blade design. Therefore, the deformable device according to the invention provides another degree of freedom for control mechanisms used to regulate the power output of a wind turbine and the load level at the blades or corresponding turbine. Power generation before rated power can be increased to improve the turbine's annual energy output, while it can also be used to reduce load levels under certain conditions. The deformable device can also be used for de-icing purposes to prevent ice buildup in the leading edge region, thus covering the device. The ice can be broken up and removed by simply actuating the actuation device and moving the housing.

[0010] Crucially, the housing of this deformable device moves relative to the rigid blade body or corresponding leading edge region via the actuation device. This movement can be a simple linear movement, such that the actuation device simply pushes the housing away from the leading edge region with a linear motion as it moves the housing from a first position to a second position. However, it can also be a bending movement, where the actuation device bends the housing upwards or downwards, respectively, toward the suction-side or pressure-side surface of the blade. Of course, both movements can also be superimposed or simultaneous, applying specific linear and bending movements to the housing. Clearly, there are multiple degrees of freedom in terms of movement or the corresponding direction of movement, and therefore, multiple degrees of freedom in terms of overall cross-sectional shape and aerodynamic geometry.

[0011] According to a first embodiment, the housing is fixed to the suction-side and pressure-side surfaces of the blade body at two longitudinal ends and includes at least one elastic segment that extends when the housing moves from the first position to the second position. The housing covering the leading edge is fixed to the blade body at both ends, i.e., the corresponding upper and lower suction-side and pressure-side surfaces, such that the housing is securely attached to the blade body while covering the leading edge along its length. An airtight transition from the housing to the blade body is preferred at the two longitudinal end regions. To allow movement of the housing relative to the blade body to be initiated by an actuation device, the housing includes at least one elastic segment, meaning that the housing itself is elastic at least in a portion and is accordingly made of an elastic material. This elastic segment extends or stretches when the housing is moved out of the first position by the actuation device. The housing remains fixed at both ends, and therefore the leading edge is still surrounded or enclosed by the housing, while the housing changes shape. By stretching and pulling the elastic segment, a restoring force is generated due to the elastic nature of the elastic segment. When the actuating device retracts the housing from the second position back to the first position, this restoring force ensures that the housing or the corresponding stretched elastic portion will return to its unstretched shape. Since the housing includes at least one elastic segment, it should be noted that the remaining one or more segments of the housing are inelastic, correspondingly rigid, or much more rigid than the elastic segment.

[0012] In another embodiment of this alternative, the housing may include a first elastic segment adjacent to or fixed to the suction-side surface and a second elastic segment adjacent to or fixed to the pressure-side surface, as well as a more rigid third segment connecting the first and second elastic segments. In this embodiment, the first and second elastic segments extend or stretch when the housing is removed from a first position. The two elastic segments are connected by a third segment, which is more rigid or completely rigid and stiff, and bends accordingly based on the shape of its leading edge. An actuation device may, for example, be coupled to this rigid third segment and actuate it to move the housing, thereby changing the housing geometry accordingly. The housing or the corresponding elastic segment is preferably directly fixed to the blade body by means of a corresponding fixing element, while it is also possible that each of the first and second elastic segments is connected to a more rigid connecting segment through which the housing is connected to the blade body.

[0013] In an alternative embodiment, the housing may include a first more rigid section adjacent to or fixed to the suction-side surface, a second more rigid section fixed to the pressure-side surface, and an elastic section connecting the first and second more rigid sections. In this embodiment, when the housing moves and correspondingly changes its geometry, the intermediate section, i.e., the elastic third section, is stretched. The more rigid section located at the longitudinal end of the housing is firmly fixed to the blade body by means of a corresponding fixing device and does not move; only the elastic intermediate section is stretched. Furthermore, this embodiment allows for significant changes in the housing geometry and therefore the blade geometry.

[0014] In the third embodiment, the housing is secured to the suction-side and pressure-side surfaces via two longitudinal ends and is fully elastic. In this embodiment, the housing does not include rigid sections, except optionally two small longitudinal connecting sections arranged at the ends of the elastic housing for connecting it to the blade body. When the actuation device moves the housing from a first position to a second position and thus changes its geometry, the housing is fully stretched over its entire area. Therefore, here the housing is made entirely of an elastic material, rather than only partially of an elastic material as in the previous embodiments, where the housing was also segmented from more rigid or inelastic materials.

[0015] As mentioned, regardless of its arrangement, the housing is securely attached to the blade body via two longitudinal ends. This attachment can be achieved in various forms. For example, the housing can be secured to the blade body using appropriate fasteners such as bolts or screws. Preferably, the housing is secured to the blade body by gluing it with a suitable adhesive or resin, which allows for a very strong attachment and a smooth transition from the housing to the blade body, which is advantageous in terms of aerodynamic properties.

[0016] The previously described embodiments relate to a housing fixed to the blade body at two longitudinal ends and at least partially or fully elastic, the elasticity allowing the housing's form or shape to be changed by stretching it. An alternative embodiment of this at least partially or fully elastic housing proposes a rigid housing that is pivotally fixed to either the suction-side or pressure-side surface at only one longitudinal end. In this embodiment, the housing is rigid and stiff, and constructed of a corresponding material that does not possess the relevant elastic properties. Therefore, when moving from a first position to a second position, the general geometry or shape of the housing does not change, but the position of the housing relative to the leading edge changes by pivoting it. To allow this pivoting movement, the rigid housing is fixed to the blade body at only one longitudinal end, providing a pivot axis about which the housing can rotate when the actuation device moves it out of the first position. Preferably, the housing is fixed to the suction-side surface of the blade and thus raised from the pressure-side surface with the other unfixed end resting on the pressure-side surface in the first position. If desired, the arrangement can also be reversed, and the housing can be fixed to the pressure-side surface.

[0017] Therefore, the present invention covers two main housing embodiments: the first comprising a housing having at least one elastic segment and at least one rigid segment, or a fully elastic housing; and the second alternative comprising a fully rigid and stiff but pivotable housing. According to the invention, the elastic segment or the entire elastic housing may be made of a pad-like or foil-like material based on an elastic polymer, such as an elastomer or rubber material. The rigid segment or the entire rigid housing may be made of a material based on a rigid polymer, with or without integrated fibers. The one or more segments or the entire housing may be made of resin, for example, with embedded glass or carbon fibers. Thus, it may be made solely of a polymer matrix material or manufactured as a fiber composite component. It should be noted that the materials mentioned above are not limiting but merely examples, as various elastic and inelastic materials are suitable for constructing the respective housings.

[0018] As mentioned, the actuation device is used and adapted to move the housing. In a first embodiment, the actuation device can be a pneumatic or hydraulic actuation device. It is coupled to a corresponding pneumatic or hydraulic circuit including a pump and, for example, a hydraulic fluid reservoir. Preferably, the actuation device, especially a pneumatic actuation device, includes at least one inflatable bladder disposed between the blade body and the housing. The bladder can be inflated, for example, using a gaseous medium, preferably air. Because it is disposed between the blade body and the housing, the housing moves from a first position to a second position when the bladder is inflated, and returns to the first position when the bladder is deflated. This restorative movement back to the first position may be caused by the stretching and pulling of the elastic material of the housing, or, in the case of a completely rigid or stiff housing, by means of some retraction element such as a spring, or by the bladder itself, in the case of its firm attachment to the housing. Using one or more such bladders is very advantageous because they can be inflated and deflated using gas, preferably air, without adding any weight to the blade. Furthermore, the capsule can completely collapse when it is expanded or contracted, making it certain that the shell will always return from the second position to the first position.

[0019] In another embodiment of this bladder arrangement, two or more bladders may be arranged side-by-side, viewed from the suction side to the pressure side, each bladder capable of inflating individually. This actuation mechanism or arrangement allows for a wide alteration of the overall geometry of the casing, and thus of the blade leading edge region, by individually inflating or deflating one or more of these bladders. For example, three bladders may be arranged: one closer to the suction side, one at the leading edge tip, and one closer to the pressure side. Depending on which bladder is inflated, stretching or bending deformation can be achieved to broadly alter the overall cross-sectional shape. This allows for even a reduction in lift generated by the blade section, thus functioning as a leading-edge spoiler device, for example, by inflating only the bladder closest to the suction side of the blade, while of course achieving other effects as well.

[0020] Additionally or alternatively, viewed along the longitudinal direction of the blade body, two or more bladders may be arranged spaced apart from each other, each bladder capable of inflating individually. In this embodiment, two or more individual bladders are locally distributed along the length of the area covered by the shell. Each of these individual local bladders can inflate individually. This actuation mechanism allows for changes in geometry along the spanwise direction, which can result in different levels and geometries of actuation at different locations along the leading edge. Thus, viewed along the longitudinal or spanwise direction, it allows for localized changes in geometry because, in this embodiment, the flexible or elastic shell only extends locally and moves from its position near the leading edge. When the spaced bladders are inflated, viewed along the longitudinal direction, the leading edge is provided with a tubercle extending at or around the leading edge, which is known to reduce noise and improve aerodynamic performance. The more individual inflatable bladders arranged along the leading edge between the blade body and the elastic shell or the elastic portion of the shell, the more tubercles can be provided. It should be noted that this arrangement can also be combined with a previous arrangement that includes several adjacent bladders viewed from the suction side surface to the pressure side surface, thereby allowing such a protrusion and / or enabling the entire shell to move partially or completely along its length.

[0021] In an alternative using one or more bladders, the actuation device may also include one or more positioning cylinders, each comprising a movable piston connected to the housing. These cylinders are arranged at the blade body, with the piston connected to the housing. The housing is moved when the piston is removed from a non-movable cylinder, regardless of the housing's orientation. Preferably, these cylinders are simultaneously controllable, but each cylinder can also be controlled individually to provide another degree of freedom in changing the housing's shape.

[0022] In an alternative, the actuation device may include one or more push rods connected to the housing, which can be moved by means of an electric actuator, such as an electric motor. For example, the push rod may be part of an electric spindle actuator with a rotating nut driven by the electric actuator, through which the spindle moves. The spindle is coupled to the housing, which can be moved by the longitudinally moving spindle. Alternatively, the push rod may also be coupled to an electric eccentric actuator. The push rod is, for example, eccentrically fixed to a rotating disk that is rotated by an electric actuator. Due to this eccentric arrangement, the push rod moves as the disk rotates, thereby moving the housing.

[0023] While the housing may move only between a first position near the edge and a second position that is extended or spaced out, it is certainly possible for the actuating device to move and fix the housing to one or more intermediate positions or any intermediate position between the first and second positions. This means that the first and second positions define the maximum or end position, while any intermediate position in between can also be controlled and fixed by the actuating device.

[0024] Finally, the present invention also relates to a wind turbine comprising one or more turbine blades as previously described. Attached Figure Description

[0025] Other objects and features of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. However, the drawings are merely schematic diagrams designed for illustrative purposes only and do not limit the invention. The drawings show:

[0026] Figure 1 A schematic diagram of the wind turbine of the present invention is shown.

[0027] Figure 2 A schematic diagram of a portion of the turbine blade of the present invention is shown in cross-sectional view, wherein the deformation device is in a first position.

[0028] Figure 3 It shows Figure 2 In one embodiment, the deformation device is in the second position.

[0029] Figure 4 A second embodiment of the wind turbine of the present invention is shown, wherein the deformation device is in the first position.

[0030] Figure 5 It shows Figure 4 In one embodiment, the deformation device is in the second position.

[0031] Figure 6 A third inventive embodiment of a turbine blade is shown, wherein the deformation device is in a first position.

[0032] Figure 7 It shows Figure 6 In one embodiment, the deformation device is in the second position.

[0033] Figure 8 A fourth embodiment of the invention is shown, wherein the segmented deformation device is in the second position.

[0034] Figure 9 A fifth embodiment of the invention is shown, wherein the deformation device is in the first position.

[0035] Figure 10 It shows Figure 9 In one embodiment, the deformation device is in the second position.

[0036] Figure 11 A sixth embodiment of the turbine blade of the present invention is shown, wherein the deformation device is in a first position.

[0037] Figure 12 It shows Figure 11In one embodiment, the deformation device is in the second position, and

[0038] Figure 13 A seventh embodiment of the turbine blade of the present invention is shown, wherein the deformation device is in a second position. Detailed Implementation

[0039] Figure 1 A schematic diagram of the wind turbine 1 of the present invention, including a tower 2, is shown. The tower 2 has a nacelle 3 disposed at the top of the tower. The nacelle includes a hub 4, to which, in this embodiment, three turbine blades 5 are attached; these turbine blades 5 may also be referred to as rotor blades. The turbine blades 5 interact with blowing wind, causing the hub 4 to rotate. The hub is coupled to a generator, which, as is known, is driven by the rotating hub to generate electricity.

[0040] Each turbine blade includes a blade body 6 having a leading edge 7a and a trailing edge 7b. This blade body is typically manufactured as a hollow structure comprising a blade body shell made of a fiber-reinforced polymer; thus, the blade body is a fiber composite component with several fiber pads embedded in a resin matrix. As is also known, the blade body is reinforced by means of corresponding webs arranged within it.

[0041] Each turbine blade 5 of the present invention is characterized by having a specific deformation device arranged at the leading edge on the blade body. Figure 2-13 Various embodiments of such a deformable device are shown, which allow for changes in the geometry of the turbine blade 5 in the leading edge region, thereby altering the aerodynamic properties of each corresponding turbine blade 5.

[0042] Figure 3 A first embodiment of the turbine blade 5 is shown as a partial cross-sectional view. This view shows the leading edge 7 realized at the corresponding blade body 6, which is shown as a hollow body. Attached to the blade body 6 is a deformation device 8, which includes a housing 9 secured to the blade body 6 by means of two longitudinal ends 10. This securing can be achieved by a separate fastening device such as screws or bolts, or, in a preferred alternative, by means of an adhesive or bonding agent that firmly bonds the housing 9 to the blade body. Such an adhesive can be, for example, a cured resin that secures or embeds the respective longitudinal ends 10 into the blade body 6.

[0043] In this embodiment, the housing 9 is made entirely of an elastic material, such as a material based on an elastic polymer, which is adapted to be stretched and automatically returns to its initial or initial position due to the restoring force accumulated within the elastic material when stretched. Clearly, the housing 9 is attached at one end to the suction-side surface 11 of the blade body 6 and at the other end to the pressure-side surface 12 of the blade body 6, such that the pad-like or foil-like housing 9 covers the entire leading edge 7a. Viewed along the longitudinal direction of the turbine blade 5, it also extends at least partially along the length of the leading edge 7a, covering a considerable portion of its length.

[0044] The turbine blade 5 also includes an actuator 13 adapted to move the casing 9 from... Figure 2 The first position shown is moved to, as Figure 3 The second position shown in the first position is very close to the blade body 6 or the corresponding leading edge 7a, and in the second position it is spaced apart from the leading edge 7a. In this example, the actuating device 13 is a pneumatic actuating device, which includes at least one inflatable bladder 14 disposed between the blade body 6 and the housing 9, such as Figure 2 and Figure 3 As shown in the diagram. The inflatable bladder 14 is coupled to a pump 15 controlled by a control device 16. It should be noted that more than one inflatable bladder 14 may be arranged along the length of the leading edge 7a or the corresponding housing 9, but a single long inflatable bladder 14 may also be provided.

[0045] If, for example, to control the generated power, the overall geometry of the turbine blades 5 or the corresponding aerodynamic airfoil shape needs to be changed, then the control device 16 controls the pump 15 to inflate the inflatable bladder 14, thereby changing its shape and form and stretching the shell 9, such as... Figure 3 As shown in the diagram, since the housing 9 is fixed to the blade body 6, it is stretched according to the cross-sectional shape of the inflatable bladder 14, which extends significantly from the suction-side surface 11 to the pressure-side surface 12, thus covering the leading edge 7a. Figure 2 and Figure 3 As clearly shown, the width of turbine blade 5 can be altered by variations at the leading edge 7a, thus affecting aerodynamic properties.

[0046] If this form change is no longer needed, the control device 16 controls the pump 15 or the deflation valve, etc., to deflate or deflate the inflatable bladder 14, resulting in another form change. The stretched shell 9 extends from... Figure 3 The second position returns according to Figure 2 The first position is changed, and thus, the cross-sectional shape of the turbine blade 5 is changed again.

[0047] It is important to note that, in Figure 2 and Figure 3 Between the first and second positions shown, one or more intermediate positions can be controlled according to the degree of inflation of the inflatable bladder 14.

[0048] Figure 4 and Figure 5 Another embodiment of the turbine blade 5 of the present invention is shown, wherein the same reference numerals are used for the same objects in the following description of all the figures. Figure 4 and Figure 5 The blade body 6 is shown again, including the deformable device 8 of the entire housing 9 attached to the blade body 6 along its longitudinal end 10. It also covers the leading edge 7a from the suction side surface 11 to the pressure side surface 12, and also covers a considerable length of the leading edge 7a.

[0049] In this embodiment, different actuation devices 13 are provided. The actuation device 13 includes one or more positioning cylinders 17 controlled by the control device 16. For example... Figure 4 and Figure 5 As shown, the positioning cylinder 17, or each positioning cylinder 17, includes a linearly movable piston 18. The piston 18, or each piston 18, is coupled to the housing 9. For this coupling, the end or tip of the piston 18 may be provided with some kind of circular coupling device, which corresponds in some way to the shape of the leading edge 7a, and therefore to the shape of the housing 9, such that the force acting on the housing 9 is distributed over a larger and geometrically defined area.

[0050] If the form of the turbine blade 5 is to be changed, the control device controls the positioning cylinder 17 or each positioning cylinder 17, causing the corresponding piston 18 to move out of the positioning cylinder 17, thereby moving the housing 9 from the position according to the... Figure 4 The first position is stretched to according to Figure 5 The second position, where it significantly alters the overall shape of turbine blade 5 in the leading edge region.

[0051] If the change in form is to be reversed again, the control device 16 controls the positioning cylinder 17 or each positioning cylinder 17 to retract the corresponding piston 18, so that it moves back into the positioning cylinder 17, the movement being supported by the restoring force of the stretched housing 9.

[0052] Because the pad-shaped or foil-shaped housing 9 extends over a considerable length of the leading edge 7a, more than one positioning cylinder 17 is typically provided, which can be coupled to a common connection device that connects the piston 18 to the housing 9. Each positioning cylinder 17 can be controlled individually or via a common control device 16.

[0053] Figure 7A third embodiment of the turbine blade 5 of the present invention is shown, which also includes a blade body 6 having a leading edge 7, and a deformation device 8 comprising a housing 9 of the entire elastic pad or foil shape, which is fixed to the blade body 6 by means of its longitudinal end 10 at its suction-side surface 11 and pressure-side surface 12. In this third embodiment, a different actuation device 13 is again provided compared to the previous first and second embodiments. This actuation device includes an eccentric electric actuator 19 having a rotating disk 20 and an electric motor 21 controlled by a control device 16. The rotating disk 20 rotates about a fixed axis of rotation as indicated by arrow P1 and is coupled to the housing 9 by a push rod 22. The push rod 22 is eccentrically arranged at the disk 21. Similarly, in this embodiment, a connecting device may also be positioned at the end of the push rod 22, thereby allowing a plurality of push rods to be arranged along the length of the leading edge 7.

[0054] exist Figure 6 In this configuration, the housing 9 is positioned in a first location near the blade body 6 or the corresponding leading edge region. The push rod 22 is in the retracted position. When the rotating disk 20 is rotated as indicated by arrow P1 at this time, the push rod 22 moves due to its eccentric fixation at the rotating disk 20. Thus, as... Figure 7 The stretched housing 9 is shown. The aerodynamic airfoil profile of the turbine blade 5 changes. When this change in form is reversed, the rotating disk 20 rotates again as shown by arrow P2, which is shown in the same direction of rotation as arrow P1. During this rotation, the push rod 22 retracts, thereby also retracting the housing 9, which supports this reverse movement by its inherent restoring force.

[0055] Figure 8 A fourth embodiment of the turbine blade 5 of the present invention, having a blade body 6 and a leading edge 7, is shown, also including a deformable device 8 of the entire elastic foil-like or pad-like housing 9 attached along its longitudinal end 10 to the suction-side surface 11 and the pressure-side surface 12. This embodiment is similar in aspect to the actuation device 13. Figure 3The embodiments are similar. In this embodiment, the actuation device 13 includes, for example, three inflatable bladders 14a, 14b, and 14c arranged side-by-side when viewed from the suction side surface 11 to the pressure side surface 12. Each inflatable bladder 14a, 14b, and 14c can be individually inflated by a pump 15 controlled by a controlled device 16. A valve 23 may be provided to individually control each inflatable bladder 14a, 14b, and 14c. Furthermore, the mechanism may define degrees of freedom for changing the actuable form. The leading edge region can be asymmetrically shaped depending on which inflatable bladder or combination of inflatable bladders is inflated. For example, only inflatable bladder 14a may be inflated without inflating the other two inflatable bladders. Only inflatable bladder 14b may be inflated, or only inflatable bladder 14c may be inflated. Furthermore, the two inflatable bladders, such as inflatable bladders 14a and 14b, can be inflated, but inflatable bladders such as 14c cannot be inflated. Clearly, there are various variations on how the cross-sectional shape can be modified by using multiple sub-units in the form of separate inflatable bladders 14a, 14b, and 14c.

[0056] Figure 9 and Figure 10 The turbine blade 5 of the present invention is shown, which corresponds to the actuator 13. Figure 2 and Figure 3 In this embodiment, the turbine blade 5 includes a blade body 6, to which a deformable device 8 comprising a housing 9 is attached along its longitudinal end 10. Between the leading edge 7a or a corresponding leading edge region and the housing 9, at least one inflatable bladder 14 is also arranged and coupled to a pump 15 controlled by a control device 16. In this embodiment, the housing 9 is not entirely made of an elastic material, but only partially. It includes: a first elastic segment 24a having a first longitudinal end 10 connected to the suction-side surface 11; and a second elastic segment 24b having a second longitudinal end 10 fixed to the pressure-side surface 12. Between the first elastic segment 24a and the second elastic segment 24b, made of a pad-like or foil-like elastic material similar to a polymer, a more rigid third segment 24c having a rigid shape is arranged, which is fixed or connected to the first elastic segment 24a and the second elastic segment 24b. The third segment 24c may be made of a rigid polymer or polymer compound and helps to provide a rigid surface in the area near the erosion zone of the leading edge 7a of the protective blade body 6.

[0057] When the form needs to be changed, the inflatable bladder 14 is inflated, causing the shell 9 to expand and from the position according to... Figure 9 The first position is moved to according to Figure 10The second position. By doing so, only the first elastic segment 24a and the second elastic segment 24b are stretched, while the third segment 24c remains unchanged in shape. Similarly, when the change in form is to be reversed again, it is only necessary to expand or contract the inflatable bladder 14, so that the stretched first elastic segment 24a and the second elastic segment 24b retract the third segment 24c back to the first position.

[0058] As an explanation, Figure 9 and Figure 10 The embodiments shown can also be reversed in terms of the stiffness and elasticity of the segments. Of course, the segments at the longitudinal ends can also be made more rigid than the elastic or flexible middle segments. Similarly, the housing 9 comprises three separate segments, but it is rigid at the longitudinal ends and flexible in the middle. When the inflatable bladder 14 is inflated, the elastic or flexible middle segments are stretched and extended, while the more rigid segments at the longitudinal ends remain unchanged in shape.

[0059] Figure 11 The embodiment shown illustrates a sixth embodiment of the turbine blade 5, which includes a blade body 6 having a leading edge 7a, which is also covered by a deformation device 8. This deformation device 8 also includes a housing 9, but here the housing 9 is attached to the suction-side surface 11 only by one longitudinal end 10. The other longitudinal end 10 is not fixed to the blade body 6.

[0060] Similarly, in this embodiment, the actuating device 13 includes an inflatable bladder 14 coupled to a pump 15 controllable by a control device 16. The housing 9 is hinged to the blade body 6, allowing the housing 9 to rotate about its fixed axis at its longitudinal end 10. To change shape, the inflatable bladder 14 is inflated and widened. This causes the rigid and stiff housing 9, in this embodiment, to rotate about its fixed portion along its longitudinal end 10, causing it to bend in a certain way toward the suction-side surface 11. Figure 12 As clearly shown, the lower longitudinal end 10 is moved away from the blade body 6 or the corresponding pressure side surface 12 by one point.

[0061] In this embodiment, the inflatable bladder 14 can be securely fixed to the housing 9, which, as mentioned, is rigid and therefore does not accumulate any restoring force when moved from the first position to the second position. To reverse this movement, when the inflatable bladder 14 is deflated, the collapsed inflatable bladder 14 causes the rigid housing 9 to retract and bring it back to its first position near its leading edge.

[0062] at last, Figure 13An embodiment of a turbine blade 5 having a blade body 6 is shown, in which a deformable device 8 including a housing 9 is attached to the blade body 6 in the manner previously mentioned. Also in this embodiment, the housing 9 is fully resilient and is secured to the blade body 6 by means of two longitudinal ends 10.

[0063] Here, the actuation device 13 includes several separate inflatable bladders 14d, 14e, and 14f, arranged spaced apart from each other when viewed along the longitudinal direction of the blade body, each inflatable bladder 14d, 14e, and 14f being inflatable individually. They are coupled to a pump 15 controlled by a control device 16. Similarly, a controllable valve 23 can be provided to individually control each inflatable bladder 14d, 14e, and 14f.

[0064] This embodiment is designed in such a way that, in addition to as according to Figure 8 The multi-chambered capsule arrangement, as depicted, allows for actuation not only along the chord direction but also along the span direction. This is because the inflatable capsules 14d, 14e, and 14f are distributed along the length of the leading edge 7 and extend around it, thus distributing and extending along the span direction. This allows for the creation of protruding regions along the leading edge 7a, which resemble bulges extending from the leading edge 7a, thereby stretching the shell 9 only locally. Figure 13 A schematic diagram of this embodiment is shown, clearly illustrating that each individual inflatable bladder 14d, 14e, 14f produces an individual bulge or protrusion. This form variation allows for noise reduction and improved aerodynamic performance.

[0065] This invention adds another degree of freedom for controlling or regulating the power output and load level of a wind turbine. Power generation before rated power can be increased to improve the turbine's annual energy output, while load levels can be reduced under certain conditions. Furthermore, if ice has formed on the blade surface, de-icing is possible by simply moving the housing 9 that breaks the ice. Moreover, aeroacoustic noise emissions can also be reduced. All of this is possible because the arrangement of the deformable device 8 covers the leading edge 7a and, as previously described, alters the overall edge form or shape. Any movement of the corresponding housing 9 results in a shape change, which in turn leads to a change in aerodynamic properties. Preferably, not only the first and second positions but also intermediate positions can be controlled, with multiple controllable forms or shapes, allowing for specific control, such as power output and load level.

[0066] For example, actuating the device to produce a positive camber can generate increased lift, and thereby improve the power generation of the wind turbine at wind speeds below its rated speed. Alternatively, actuating the device to produce a negative camber can reduce the lift generated by the blades, and thereby reduce the load on the turbine, which can be beneficial under certain wind conditions, especially near the shoulder of the power curve, a design driver for blade design.

[0067] Actuating only the section below the leading edge can produce a sharper leading edge and increase the short length, which can increase the lift-to-drag ratio under nominal operating conditions, thus leading to an improvement in AEP.

[0068] If required by the original blade design, actuating the deformation device in some way can also increase the leading edge radius, thereby increasing the robustness of the blade section to dirt and other surface impurities.

[0069] Actuation that varies along the wingspan can also produce features such as protrusions, which can help reduce noise emissions under certain operating conditions. Protrusions can also function as vortex generators, thereby helping to improve robustness to contaminants, inflow turbulence, shear, and other inflow conditions.

[0070] Finally, the periodic activation and deactivation of the device can also serve as a defrosting mechanism (surf), thereby helping to remove the ice buildup on the leading edge.

[0071] Although the invention has been described in detail with reference to preferred embodiments, the invention is not limited to the disclosed examples, and other variations can be derived by those skilled in the art from the disclosed examples without departing from the scope of the invention.

Claims

1. Turbine blade for a wind turbine (1), comprising a blade body (6) having a leading edge (7a), characterized in that, The blade body (6) is provided with a deformation device (8) covering the leading edge (7a) and extending at least partially along the leading edge (7a), the deformation device (8) comprising a housing (9) fixed to the blade body (6), the housing (9) being movable by means of an actuation device (13) between a first position close to the leading edge (7a) and a second position away from the leading edge (7a), wherein the housing (9) is fixed to a suction side surface (11) and a pressure side surface (12) of the blade body (6) with two longitudinal ends (10) and comprises a first more rigid section (24a) close to or fixed to the suction side surface (11) and a second more rigid section (24b) fixed to the pressure side surface (12) and a third elastic section (24c) connecting the first more rigid section (24a) and the second more rigid section (24b), and wherein the third elastic section (24c) is configured to be stretched when the housing (9) is moved from the first position to the second position.

2. The turbine blade of claim 1, wherein The third elastic section (24c) of the housing (9) is made of a mat-like or foil-like elastic polymer-based material, while the first more rigid section (24a) and the second more rigid section (24b) are made of a rigid polymer-based material with or without integrated fibers.

3. The turbine blade of any one of claims 1-2, wherein, The actuation device (13) is a pneumatic or hydraulic actuation device.

4. The turbine blade of claim 3, wherein, The actuation device (13) comprises at least one inflatable bladder arranged between the blade body (6) and the housing (9).

5. The turbine blade of claim 4, wherein, Two or more inflatable bladders are arranged side by side, each inflatable bladder being inflatable individually, and / or two or more inflatable bladders are arranged spaced apart from each other, each inflatable bladder being inflatable individually, as seen from the suction side surface (11) to the pressure side surface (12) and / or as seen in the longitudinal direction of the blade body (6).

6. The turbine blade of claim 3, wherein, The actuation device (13) comprises one or more positioning cylinders (17) comprising a movable piston (18) connected to the housing (9).

7. The turbine blade of any one of claims 1-2 and 4-6, wherein, The actuation device (13) comprises one or more push rods (22) connected to the housing (9) and movable by means of an electric drive (21).

8. The turbine blade of claim 7, wherein, The push rod (22) is part of an electric spindle drive or is coupled to an electric eccentric drive (19).

9. The turbine blade of any one of claims 1-2, 4-6, and 8, wherein, The actuation device (13) is adapted to move the housing (9) to one or more defined intermediate positions or any intermediate position between the first position and the second position.

10. Wind turbine comprising one or more turbine blades (5) according to any of the preceding claims.

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