JP2016109138A - Wind turbine blade including air leakage guard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wind turbine blade capable of reducing air leakage between an inner blade section and an outer blade section, and to provide a quick and simple method for maintaining an aerodynamic effect of the wind turbine blade while reducing air leakage within a normal pitch range.SOLUTION: A wind turbine includes at least one wind turbine blade 5 having an inner blade section 6 and an outer blade section 7 separated by a pitch junction 8. A first seal element 13 is disposed to cover an air gap of the pitch junction at a positive pressure side of the blade sections. At least one second seal element is disposed at a negative pressure side of at least one of the blade sections. The first and second seal elements act as air barrier when a pitch angle of the outer blade section changes to a set pitch angle or less, and prevent air leakage from the positive pressure side to the negative pressure side.SELECTED DRAWING: Figure 2

Description

The present invention
A wind turbine tower having an upper end;
-A nacelle located at the upper end of the wind turbine tower;
A rotor hub rotatably connected to the nacelle; at least one wind turbine blade connected to the rotor hub, wherein the at least one wind turbine blade has a first side and a suction side forming a pressure side; And at least one wind turbine blade having an inner blade section connected to the outer blade section via a pitch junction, and using the pitch bearing system, the outer blade section is The pitch junction is configured to vary with respect to the blade section, the pitch junction having a first end disposed in the inner blade section, and the first end disposed in the inner blade section is the outer blade section. At least one facing the second end located at With two wind turbine blades,
A wind turbine comprising:

  The present invention also relates to a method of operating a wind turbine as described above, the method comprising changing the pitch angle of the outer blade section relative to the inner blade section when the wind speed is above a first nominal wind speed during normal operation. including.

  It is known that the pitch junction of a partial pitch wind turbine includes an air gap located between the blade extension / inner blade section and the outer blade section. The air gap is formed by a pitch bearing system having first and second bearing elements / rings attached to each of the blade sections, allowing the outer blade section to change the pitch angle relative to the inner blade section. The air gap causes air leakage from the positive pressure side to the negative pressure side, particularly during operation. Therefore, air around the pitch junction is sucked from the positive pressure side profile to the negative pressure side. This reduces the efficiency of the wind turbine blade and thus the power production of the wind turbine.

  U.S. Pat. No. 6,057,031 discloses a conventional full span wind turbine blade with one or two additional aerodynamic edge extensions attached to the blade root. A continuous row of brushes is arranged along the periphery of the combined profile of the blade root and the edge extension. The brush bristles allow air to flow from the pressure side to the suction side through the air gap between the wind turbine blade and the rotor hub. Furthermore, if the same length of bristle is used, the brush cannot close the air gap substantially along the chord of the wind turbine blade due to the outer profile of the rotor hub. During operation, the pressure and air flow on the pressure side increase from the root to the tip of the blade, which means that the bristles are bent further, so more air passes through the air gap. As it allows, bristle is not an effective solution for reducing air leakage between two blade sections in a wind turbine blade.

  Another solution is disclosed in US Pat. In this solution, one or two bridging elements are placed inside the air gap to surround the air gap between the inner and outer blade sections. The bridging element forms a solid or shell element that extends along both the pressure side and the suction side. If a single bridging element is attached to both blade sections, the bridging element will stretch / deform significantly at the trailing edge when the pitch angle changes or is sufficient to accommodate the pitch angle change. Must contain extra material. This extra or highly elastic material tends to be bent out of control when affected by the incoming wind. The use of two bridging elements increases the potential contact area between the two bridging elements, and the possibility of wear of the bridging elements and one of the elements is disengaged from the respective blade section. Increase the risk of receiving power.

  Yet another solution is disclosed in US Pat. In this solution, a protruding collar is placed at the pitch junction between the inner and outer blade sections. The collar comprises an aerodynamic streamlined structure that extends over most of the air gap and extends over an anchor plate to which the interconnect wires disposed between the individual collars are attached. However, because this collar cannot change the pitch angle with the blade section because of this anchor material, either the collar or the blade section can be used to allow the blade section to change the pitch angle relative to the streamlined structure. An air gap is required between them.

  It is also known to place one or more stall fences at or near the pitch junction. However, such stall prevention fences are specifically designed to function outside the normal pitch range and at much higher wind speeds.

  U.S. Patent No. 6,099,077 discloses a wind turbine blade having a main wing element and a plurality of wing-shaped elements attached to the trailing edge area of the main wing element. The wing-shaped elements are spaced apart to form a gap in which rubber lips are disposed along both the pressure and suction sides to seal the gap and prevent dust and moisture from entering the gap.

US Patent No. US8403642B1 Denmark DK177305B1 International Publication No. WO2010 / 046760A2 Denmark DK2013370434A1

  It is an object of the present invention to provide a wind turbine blade with another solution that reduces air leakage between the inner and outer blade sections.

  It is an object of the present invention to provide a wind turbine blade that reduces air leakage within a normal pitch range.

  The object of the present invention is to provide a quick and simple method for maintaining the aerodynamic effects of wind turbine blades in the normal pitch range.

  The object of the invention is achieved by a wind turbine characterized in that at least one first sealing element is arranged on only one side, for example the pressure side, of at least one side of the inner and outer blade sections. . At least one first sealing element extends over the pitch junction and abuts the other blade section, eg, the same side of the other blade section, and the at least one first sealing element is substantially It is impervious to air.

  “Arranged in” is defined as each element being located on the side or directly on the end face and no more than 150 millimeters from the adjacent edge between the end face and the side face. “Air impervious” means that each element can substantially prevent air / wind from passing through the element.

  This configuration reduces the amount of air leakage from the pressure side to the suction side when the outer blade section changes pitch angle relative to the inner blade section, thereby increasing the efficiency and power production of the wind turbine blade. The first set of sealing elements differs from conventional skins or covers that extend along the entire circumference of the turbine blade, i.e., both on the pressure side and the suction side, only along the pressure side and optionally on the wind turbine blade. Arranged along the trailing or leading edge. This reduces the amount of material required and simplifies the assembly process. This further allows the first sealing element to regain its initial shape when the outer blade section changes pitch angle beyond the normal pitch range. This is not possible with conventional skins or covers.

  The first sealing element can be attached to or integrated with one of the blade sections, for example the inner blade section, and can extend over the entire pitch junction / air gap. The first sealing element further abuts the pressure side and / or end of the other blade section, eg, the outer blade section, effectively closing the air gap and reducing air leakage. This can reduce the total contact area between the sealing element and the blade section and thus reduce wear compared to using a bridging element located in the air gap.

  When the blade sections are aligned with each other, i.e. when the pitch angle of the outer blade section is zero, the contact area between the first sealing element and the other blade section is substantially along the pressure side. Is even. As the outer blade section begins to change pitch angles within the normal pitch range, this contact area gradually decreases in the chord direction according to the angular rotation / displacement of the outer blade section about the pitch center of the pitch bearing system. If the pitch angle change continues in either direction beyond the normal pitch range, the first sealing element gradually moves away from contact with the other blade section starting at the trailing edge and ending at the leading edge. As the outer blade section returns the pitch angle toward zero degrees, the first sealing element gradually contacts the other blade section again. The outer blade section can change pitch angle clockwise or counterclockwise, and the normal pitch range can be defined by two limit values / pitch angles.

  According to one embodiment, at least one second sealing element is arranged on at least one other side of the inner and outer blade sections, for example the suction side. At least one second sealing element extends toward at least the other blade section.

  Air leakage can be further reduced by placing at least one set of second sealing elements on the other side of each blade section. The second set of sealing elements is arranged along the suction side only and optionally along the trailing or leading edge of the wind turbine blade. The second sealing element can be attached to or integrated into one of the blade sections, for example the inner blade section, so that its free end is free to move with respect to the other blade section, for example the outer blade section. It can be so. The second sealing element reduces the amount of air that enters the air gap and passes to the negative pressure side when the first sealing element gradually moves away from contact with the other blade section due to pitch angle changes. As configured. This prevents air from leaking from the pressure side to the suction side, partly by the first sealing element and partly by the second sealing element.

  The first and second sealing elements are, for example, between zero degrees and a positive or negative pitch angle, or positive when the outer blade section changes pitch angle within a steady normal pitch range. When the pitch angle is changed between the pitch angle and the negative pitch angle, the air leakage is reduced. The pitch range is 5 to 15 degrees, for example 8 to 10 degrees.

  Two rows or more of the second sealing elements can be arranged on the suction side and / or end face of one blade section. At least one of the rows can be arranged on the end face so that the outer blade section substantially follows the pressure side of the other blade section when located at a set pitch angle. This can enhance the reduction of air leakage.

  According to certain embodiments, at least one of the inner and outer blade sections comprises a truncated trailing edge profile, at least one first or second sealing element further comprising: Placed in the trailing edge profile with the tip removed.

  One or both blade sections can be provided with a trailing edge profile with the tip removed, further arranged with a first or second sealing element. Alternatively, one or both blade sections can comprise a trailing edge profile that is sharply defined. This arrangement prevents air from entering the air gap through the trailing edge gap.

  Another seal arrangement, such as one or more deformable lips or stall prevention fences, can be installed around the pitch bearing system. The first and / or second seal elements can substantially abut the seal arrangement on the pressure side and / or the suction side so that together form a substantially continuous seal arrangement around the periphery of the pitch junction. . Alternatively, one of the first and second sealing elements can further extend around the leading edge to prevent dust and / or moisture from entering the pitch junction further into the blade section.

  According to a preferred embodiment, the at least one first or second sealing element has the shape of a deformable rigid element, for example a lip.

  At least one of the first and second sealing elements, for example the first sealing element, is configured as an air / wind impermeable element in the form of a deformable or flexible solid element. The solid element is, for example, a lip, a sleeve or a plate. The first sealing element can be made of a material such as single layer or multilayer polyethylene, polyolefin, polyurethane or any other suitable material. Alternatively, the first sealing element can comprise any type of air impermeable structure that substantially prevents air / wind from passing through the element. This allows the first sealing element to act as an air barrier at the pitch junction.

  According to a preferred embodiment, the at least one second sealing element has the shape of a brush with a plurality of deformable bristles, the bristles facing towards the other blade section.

  At least one of the first and second sealing elements, eg, the second sealing element, is configured as a brush having a support, and one or more rows of bristles are attached to the support. Alternatively, the hair can be integrated into the support. The second sealing element can comprise another air / wind permeable structure that allows substantially air / wind to pass through the element. This allows the second sealing element to better adapt to the contour of the other blade section, for example its end profile, when the pitch angle changes.

  Alternatively, the second sealing element also comprises an air / wind impervious structure that substantially prevents air / wind from passing through the element, similar to the first sealing element. In this configuration, the second sealing element can be a deformable or flexible, solid element. This allows both the first and second sealing elements to act as an air barrier at the pitch junction.

  The first and / or second sealing element is formed as a single element or as a plurality of adjacent segments. This segment can be an overlapped segment. Wind turbine blades, such as inner and outer blade sections, can have chord lengths at pitch junctions of at least 2 meters, preferably 2-5 meters, or 3-4 meters. The first sealing element can have a width, i.e. a length in the span direction, of 0.1 to 1 meter, preferably 0.2 to 0.5 meter.

  Alternatively, the first and / or second sealing element can be attached to or integrated into the other blade section, eg, the outer blade section. In yet another embodiment, the first and / or second sealing elements can be installed on both blade sections and optionally aligned with each other. In a preferred embodiment, at least another set of second sealing elements can be installed on the other blade section, for example on its pressure side or end face.

  A gap can be formed between the free end of the second sealing element and the end face of the other blade section facing it. The gap can be 5-15 millimeters, preferably 10 millimeters or less. Alternatively, the second sealing element can, for example on the suction side, extend over the edge of the other blade section and abut on its end face, for example a third end face facing the pressure side. The second sealing element has a width, ie a length in the span direction, which corresponds at least approximately to the width of the air gap, for example 1-10 centimeters. If one or both blade sections are provided with a retracted end face, i.e. a second end face, as will be explained later, the second sealing element is provided with a retracted end face and an opposite end face, e.g. the other end face. The blade section has a width less than or equal to the receded end face of the blade section, and preferably has a width of 10 to 100 centimeters, or 15 to 50 centimeters.

  According to one embodiment, at least one of the sealing elements is made of a hydrophobic material, preferably a superhydrophobic material.

  The first and / or second sealing element can be made of a water-repellent material, such as a hydrophobic or super-hydrophobic material, ie glass, silica, titanium, or any other suitable material. Alternatively, the first and / or second sealing element can be treated to obtain hydrophobic properties, for example by applying nanofabrication, coatings, or nanoparticles. This prevents moisture and ice from accumulating on the sealing element.

  According to one embodiment, at least one of the first and second end portions includes a first end surface and a second end surface, and the second end surface is a receded position with respect to the first end surface. Placed in.

  The ends of the inner and / or outer blade sections can comprise a first end region connected to an adjacent side, and optionally connected to a trailing edge with the tip removed. The first end region is further connected to the second end region, i.e., the central end region. The first end region may comprise a first end face facing the other blade section, the first end face forming the edge of its own blade section. The second end region can comprise a second end face facing the other blade section and is disposed at a position retracted relative to the first end face. The third end face is disposed between the first end face and the second end face. The third end face is substantially parallel to the pressure side and / or the suction side.

  The second sealing element can be arranged on the third end face, and its free end extends towards the facing end face of the other blade section, for example the retracted second end face. Alternatively, a second sealing element or another second set of sealing elements can be placed on the second end face.

  The partial pitch wind turbine blade may have a length of at least 35 meters from the blade root to the tip (referred to as relative length 1). The pitch junction can be arranged with a relative length of 0.20 to 0.50 with respect to the root end, and is preferably arranged with a relative length of 0.30 to 0.40.

  The object of the invention is also achieved by a method for operating a wind turbine as described above, characterized in that at least one first sealing element is installed on at least one side of at least one of the inner and outer blade sections. The At least one first sealing element abuts the other blade section when the outer blade section changes pitch angle below the first pitch angle to maintain the aerodynamic effect of the at least one wind turbine blade.

  This provides a quick and simple way to maintain the aerodynamic effect of the wind turbine blade in the normal pitch range. The first sealing element is made of a flexible or deformable material that can be bent or deflected when affected by the incoming wind. The first sealing element is attached to one blade section, for example the inner blade section, and the free end of the first sealing element is directed to the side, for example the pressure side, of the opposite blade section, for example the outer blade section. Pushed (when the incoming wind hits the pressure side of the outer blade section). This effectively closes the air gap, thus preventing air leakage from the positive pressure side to the negative pressure side.

  During normal operation, for example below the first pitch angle, by changing the pitch angle of the outer blade section, the first sealing element remains in contact with the side of the opposing blade section, for example the pressure side, Its flexible properties allow it to adapt to the angular displacement between the two blade sections. The contact area between the first sealing element and the opposing blade section varies along the chord length when viewed from the leading edge when changing the pitch angle of the outer blade section.

  The pitch system is activated at wind speeds above the nominal or rated wind speed and operates in normal operating mode. With wind speeds below the nominal wind speed, and optionally with wind speeds above the cut-in wind speed, the outer blade section can be in a neutral position, eg, a position having a zero pitch angle. In this mode of operation, the first sealing element abuts the side and thus maintains the aerodynamic effect of the wind turbine blade.

  According to one embodiment, the at least one first sealing element gradually leaves its contact with the other blade section, for example, when the outer blade section changes by more than a first pitch angle. This pitch angle change reduces the aerodynamic effect of at least one wind turbine blade.

  The first sealing element begins to move away from abutment with the other blade section at the trailing edge when the outer blade section changes pitch angle beyond the first pitch angle. As the pitch angle changes further in the same direction, the first sealing element is further away from contact with the opposing blade section as seen from the leading edge. This allows air to enter the air gap of the pitch junction, thereby causing air leakage from the positive pressure side to the negative pressure side. As a result, the aerodynamic effect of the wind turbine blade is reduced and the output is reduced.

  According to certain embodiments, the pitch angle change of the outer blade section is limited to be less than or equal to the first pitch angle during normal operation to prevent air leakage from the pressure side to the suction side.

  The change in pitch angle during normal operation can be limited to the first pitch so that the first seal element can operate as an air barrier in substantially the entire normal operating range. The change in pitch angle of the outer blade section during normal operation occurs at a wind speed below the cutout wind speed. By limiting the normal pitch range to the first pitch angle, the first sealing element remains in contact with the opposing blade section and prevents air leakage from the positive pressure side to the negative pressure side. This allows the wind turbine blade to maintain an aerodynamic effect at wind speeds up to the cutoff wind speed. On the other hand, conventional partial pitch wind turbine blades reduce aerodynamic effects and thus reduce power.

  According to one embodiment, the method further comprises the step of installing at least one second sealing element on the other side of at least one of the inner and outer blade sections, the at least one second sealing element comprising: Extends toward at least the other blade section.

  This allows both sides of the pitch junction to be closed while allowing the outer blade section to change the pitch angle relative to the inner blade section. Together, the first and second sealing elements function to prevent air leakage during pitch angle changes. When the first and second sealing elements are installed in the same blade section, both the first and second sealing elements move relative to the opposite ends of the other blade section. When the first and second sealing elements are installed in both blade sections, the first sealing element moves relative to the second sealing element or vice versa.

  According to a particular embodiment, the at least one second sealing element has at least one wind turbine blade blade when the outer blade section changes pitch angle greater than the first pitch angle and less than or equal to the second pitch angle. The loss of aerodynamic effects is reduced and one suction side of the inner and outer blade sections crosses the pressure side of the other blade section when the outer blade section changes by a pitch angle greater than the second pitch angle.

  The change in pitch angle during normal operation can be limited to a second pitch angle so that the first seal element operates as an air barrier in part of the normal operating range. The first sealing element, together with the second sealing element, acts as an air barrier in other parts of the normal operating range, reducing at least the loss of aerodynamic effects. Changing the pitch angle toward the second pitch angle means that when the first seal element moves away from contact with the opposing blade section, the second seal element gradually moves toward the first seal element. It means to change. Since the second seal element receives less air than the first seal element, the second seal element can have a different structure and / or configuration than the first seal element.

  Air leakage from the pressure side to the suction side can be further reduced by installing at least two sets of second sealing elements in the same blade section or both blade sections. Alternatively, the second sealing element can comprise an air permeable structure, for example similar to the structure of the first sealing element. This further reduces the suction effect between the pressure side and the suction side, allowing the first and second sealing elements to substantially maintain the aerodynamic effect of the wind turbine blade.

  According to one embodiment, the first pitch angle is 5 to 15 degrees and / or the second pitch angle is 6 to 35 degrees.

  The change in pitch angle during normal operation, for example, the normal pitch range, can be between zero degrees or a negative pitch angle and the first or second pitch angle. The negative pitch angle can be -15 to -5 degrees.

  The rated or nominal wind speed can be 10-15 meters / second (m / s). The cut-out wind speed can be 20 to 25 m / s. These two limit values define the normal operating range.

  The invention will be described by way of example with reference to the drawings.

1 shows an exemplary embodiment of a wind turbine according to the present invention. FIG. 2 shows the wind turbine blade of FIG. 1 viewed from the pressure side, with a first sealing element arranged with respect to the pitch junction. 1 shows a first exemplary embodiment of a pitch junction and first and second sealing elements. 2 shows a second exemplary embodiment of a pitch junction and first and second sealing elements. Fig. 4 shows a third exemplary embodiment of a pitch junction and first and second sealing elements. 4 shows a fourth exemplary embodiment of a pitch junction and first and second sealing elements. FIG. 7 shows the first and second sealing elements of FIG. 6 in a first pitch position. FIG. 7 shows the first and second sealing elements of FIG. 6 in a second pitch position.

  In the following text, the drawings will be described one by one, and the various parts and positions shown in the drawings will be numbered the same in different drawings. Not all parts and locations shown in a particular drawing are discussed together with this drawing.

  FIG. 1 shows an exemplary embodiment of a wind turbine 1 comprising a wind turbine tower 2 and a nacelle 3 arranged at the upper end of the wind turbine tower 2. A yaw bearing (not shown) is placed between the nacelle and the wind turbine tower 2 to allow the nacelle 3 to yaw against the wind turbine tower 2 using a yaw system. The rotor hub 4 is disposed with respect to the nacelle 3 and is rotatably connected to a generator (not shown) inside the nacelle 3 via, for example, a rotation shaft or a main shaft. At least one, preferably two or three turbine blades 5 are attached to the rotor hub 4. Each wind turbine blade 5 extends outward from the center of the rotor hub 4 and includes a blade root and a blade tip.

  The wind turbine blade 5 is a partial pitch blade including an inner blade section 6 and an outer blade section 7. The inner blade section 6 is connected to the outer blade section 7 via a pitch bearing (not shown) arranged between the opposite ends of the two blade sections 6, 7. The pitch bearing allows the outer blade section to change the pitch angle relative to the inner blade section using a pitch system. The pitch bearing or pitch junction is placed at a distance of relative length 0.2-0.4, as measured from the blade root. The wind turbine blade 5 has a length of at least 35 meters.

  FIG. 2 shows a pitch junction 8 disposed between the inner blade section 6 and the outer blade section 7. The pitch junction 8 includes a first end 9 disposed on the inner blade section 6, and the first end faces a second end 10 disposed on the outer blade section 7. The first end 9 and the second end 10 are spaced apart from the first side 11 of the blade sections 6, 7, for example the pressure side, to the second side 12 of the blade sections 6, 7, for example An air gap extending to the negative pressure side is formed.

  At least one or more first sealing elements 13 are arranged on the pressure side 11 from the trailing edge profile of the wind turbine blade 5, for example the blade sections 6, 7, with the trailing edge 14, for example the tip removed. , Extending toward the leading edge 15 of the wind turbine blade 5. The first sealing element 13 has a width greater than the width of the air gap so that the sealing element covers the entire pitch junction 8. The width of the first sealing element 13 is 0.1-1 meter, preferably 0.2-0.5 meter. This prevents air from leaking from the pressure side 11 to the suction side 12 when the outer blade section changes pitch angle with respect to the inner blade section 6 and maintains the aerodynamic effect of the wind turbine blade 5.

  3-8 show the pitch junction 8 as viewed from the trailing edge 14, omitting the pitch bearing system and other items. FIG. 3 shows a first embodiment of the pitch junction 8, where at least one of the wing tips 9, 10 has a first end region, eg a first end face 16, and a second end region, eg A second end face 17. Both wing tips 9, 10 can have first and second ends as shown in FIG. The first end face 16 is connected to the adjacent positive pressure side and negative pressure side 11, 12, and the second end face 17 is disposed at a position retracted from the first end face 16.

  The first sealing element 13 has the shape of an air impermeable element, for example a solid, deformable lip or a flexible lip. The first sealing element 13 is made of polyethylene, polyolefin, polyurethane or any other suitable material. In this embodiment, the first sealing element 13 is attached to the pressure side 11 of the inner blade section 6 and abuts the pressure side 11 of the outer blade section 7 using fastening means such as screws or bolts.

  One or more second sealing elements 18 are arranged on the suction side 12 and extend from the trailing edge 14 of the wind turbine blade 5 toward the leading edge 15 of the wind turbine blade 5. In this embodiment, the second sealing element 18 is attached to the third end face 19 of the wing tip 9 using fastening means such as screws or bolts. The third end face 19 is disposed between the first end face 16 and the second end face 17 and faces the positive pressure side 11 and / or the negative pressure side 12.

  The second sealing element 18 has the shape of an air impermeable element, such as a solid, deformable lip or flexible lip, and is made of polyethylene, polyolefin, polyurethane, or any other suitable material. Manufactured. The free end of the second seal element 18 extends at least over the air gap of the pitch junction 8 and abuts the third end face 19 of the wing tip 10. This further prevents air from leaking from the pressure side 11 to the suction side 12 when the outer blade section 7 changes pitch angle with respect to the inner blade section 6, thereby reducing the aerodynamic effect of the wind turbine blade 5. Loss is further reduced.

  FIG. 4 shows a second embodiment of the pitch junction 8 ′, where at least one of the wing tips 9, 10 forms a single end with a continuous end face 20. Both wing tips 9, 10 can comprise a single end region, as shown in FIG.

  In this embodiment, the first sealing element 13 ′ is attached to the pressure side 11 of the outer blade section and abuts the pressure side 11 of the inner blade section 6. The second sealing element 18 ′ is attached to the end face 20 of the inner blade section 6. The second sealing element 18 'in this embodiment has the shape of an air permeable structure in the form of a brush with a plurality of bristles. The free ends of the bristles extend at least towards the end face 20 of the outer blade section 7. This reduces the amount of air flowing through the air gap to the negative pressure side 12 while allowing the sealing element 18 ′ to better match the contour of the wing tip 9. Thereby, the loss of the aerodynamic effect of the wind turbine blade 5 is further reduced.

  FIG. 5 shows a third embodiment of the first and second sealing elements, where the first sealing element 13 is attached to the pressure side 11 of the inner blade section 6. At least two sets of second sealing elements 18 ″ are arranged at the pitch junction 8.

  One set of second sealing elements 18 "is arranged on the pressure side 11 and attached to the third end face 19 of the wing tip 10. The free end of this set is the end face 17 of the opposite wing tip 9. Another set of second sealing elements 18 ″ is arranged on the suction side 12 and attached to the third end face 19 of the wing tip 9. The free ends of this set face the end face 17 of the opposed blade tip 10.

  The second sealing element 18 ″ in this embodiment has the shape of an air permeable structure in the form of a brush with a plurality of bristles. This ensures that the sealing element 18 ″ is due to the contour of the wing tips 9, 10. While allowing a good match, the amount of air flowing through the air gap to the suction side 12 is further reduced, thereby further reducing the loss of wind turbine blade aerodynamic effects.

  FIG. 6 shows a fourth embodiment of the first and second sealing elements, where the first sealing element 13 is attached to the pressure side 11 of the inner blade section 6. The second sealing element 18 ″ ′ is arranged on the suction side 12 and attached to the third end face 19 of the inner blade section 6.

  The second sealing element 18 "'in this embodiment has the shape of an air permeable structure in the form of a brush with a plurality of bristles. The free end of the second sealing element 18"' is at least a pitch junction. 8 extends over the air gap and abuts the third end face 19 of the outer blade section 7. This reduces the amount of air flowing through the air gap to the suction side 12 while allowing the sealing element 18 "'to better match the contour of the tip 9 of the outer blade section 7, thereby reducing the wind power. The loss of the aerodynamic effect of the turbine blade 5 is further reduced.

  The second sealing elements 18 ', 18 ", 18"' shown in the embodiment of FIGS. 4-6 are made of a hydrophobic or superhydrophobic material or any other suitable material.

  Next, the operation of the present invention will be described with reference to FIGS. The outer blade section 7 has a pitch angle change in a neutral position in FIG. 6, for example, a zero pitch angle. In this neutral position, i.e., where there is no change in pitch angle, the first sealing element 13 abuts the pressure side 11 of the outer blade section 7 substantially evenly in the chord direction (shown in FIG. 2). The first sealing element 13 acts as an air barrier covering the pitch junction 8 and prevents air from leaking from the positive pressure side 11 to the negative pressure side 12.

  When the outer blade section 7 changes in pitch angle within a set pitch range, for example, below the first pitch angle, the contact area between the first seal element 13 and the pressure side 11 of the outer blade section 7 Decreases as a function of the angular displacement of the outer blade section 7 relative to the inner blade section 6 when viewed from the trailing edge 14. This configuration prevents any air leakage and thus allows the wind turbine blade 5 to maintain an aerodynamic effect within the pitch range. When the outer blade section 7 changes the pitch angle beyond the set pitch range, for example, below the second pitch angle, the first sealing element 13 gradually contacts the outer blade section 7 as shown in FIG. Leave the contact. At this time, the air gradually enters the air gap of the pitch junction 8 through the opening between the first seal element 13 and the positive pressure side 11. The second sealing element 18 "'at this time at least reduces the amount of air that flows through the air gap to the negative pressure side. This arrangement consists of the first sealing element 13 and the second sealing element 18"'. Together act to at least reduce the loss of aerodynamic effects of the wind turbine blade 5.

  When the outer blade section 7 is further changed beyond the set pitch range, for example greater than the second pitch angle, the pitch angle change causes the second sealing element 18 ″ ′ to 1, the pressure side 11 of the outer blade section 7 crosses the suction side 12 of the inner blade section 6, as shown in Fig. 8. This configuration is applied to the pitch junction 8. An air gap is formed, thereby causing air to leak from the pressure side 11 to the suction side 12. This configuration reduces the aerodynamic effects of the wind turbine 5.

  When the pitch angle changes so that the outer blade section 7 returns to the neutral position, the first sealing element 13 and the second sealing element 18 ″ ′ gradually abut against the outer blade section 7 again. The pitch junction 8 This closes the air gap, thus preventing air leakage, thereby allowing the wind turbine blade 5 to regain its aerodynamic effect.

  The invention is not limited to the illustrated embodiments or the embodiments described herein, but can be modified or adapted without departing from the scope of the invention as set forth in the claims below.

1 Wind Turbine 2 Wind Turbine Tower 3 Nacelle 4 Rotor Hub 5 Wind Turbine Blade 6 Inner Blade Section 7 Outer Blade Section 8 Pitch Junction 9 First End, Blade End 10 Second End, Blade End 11 First Side, pressure side 12 Second side, suction side 13 First seal element 14 Rear edge 15 Front edge 16 First end face 17 Second end face 18 Second seal element 19 Third end face 20 End face

Claims (14)

A wind turbine,
A wind turbine tower having an upper end;
-A nacelle arranged at the upper end of the wind turbine tower;
A rotor hub rotatably connected to the nacelle;
At least one wind turbine blade connected to the rotor hub, the at least one wind turbine blade having a first side forming a pressure side and a second side forming a suction side; The at least one wind turbine blade comprises an inner blade section connected to an outer blade section via a pitch junction, the outer blade section being pitch angle relative to the inner blade section using a pitch bearing system The pitch junction comprises a first end disposed in the inner blade section, and the first end disposed in the inner blade section is disposed in the outer blade section. At least one facing the second end And wind turbine blades,
With
At least one first sealing element is disposed on at least one of the side surfaces, eg, the pressure side, of at least one of the inner blade section and the outer blade section, and the at least one first sealing element is the Extending over the pitch junction and abutting the same side of the other blade section, e.g. the pressure side of the other blade section, the at least one first sealing element being air impermeable,
A wind turbine characterized by that. At least one second sealing element is further disposed on at least one other side of the inner and outer blade sections, such as the suction side, and the at least one second sealing element is at least on the other side. Extending towards the blade section,
The wind turbine according to claim 1, wherein: At least one of the inner and outer blade sections includes a trailing edge profile with a tip removed, and the at least one first or second sealing element is further disposed in the trailing edge profile with the tip removed. ,
The wind turbine according to claim 2, wherein: The at least one first or second sealing element has the shape of a deformable solid element, for example a lip,
The wind turbine according to claim 1 or 2, characterized in that. The at least one second sealing element has the shape of a brush with a plurality of deformable bristles, the bristles facing towards the other blade section;
The wind turbine according to claim 2, wherein: At least one of the first and second sealing elements is made of a hydrophobic material, preferably a superhydrophobic material,
The wind turbine according to claim 1 or 2, characterized in that. At least one of the first and second end portions includes a first end surface and a second end surface, and the second end surface is disposed at a position retracted from the first end surface.
The wind turbine according to claim 1, wherein: A method for operating a wind turbine according to claim 1,
-Changing the pitch angle of the outer blade section relative to the inner blade section when the wind speed exceeds a first nominal wind speed during normal operation;
Including
The at least one sealing element is installed only on one of the side surfaces of at least one of the inner and outer blade sections, and the at least one when the outer blade section changes its pitch angle by less than or equal to a first pitch angle; One first sealing element abuts the other blade section along the entire length of the at least one first sealing element to maintain the aerodynamic effect of the at least one wind turbine blade;
A method characterized by that. The at least one first sealing element, for example, gradually leaves the abutment with the other blade section when the outer blade section changes a pitch angle greater than the first pitch angle, and the pitch angle change is Reducing the aerodynamic effect of the at least one wind turbine blade;
The method according to claim 8, wherein: The pitch angle change of the outer blade section is limited to be less than or equal to the first pitch angle during normal operation to prevent leakage of air from the positive pressure side to the negative pressure side.
10. A method according to claim 8 or 9, characterized in that The method further includes installing at least one second seal element on the other side of at least one of the inner and outer blade sections, wherein the at least one second seal element is at least the other. Extending towards the blade section of the
The method according to claim 8, wherein: The aerodynamic effect of the at least one wind turbine blade when the at least one second sealing element changes the pitch angle of the outer blade section greater than the first pitch angle and less than or equal to a second pitch angle. The pressure side of one of the inner and outer blade sections crosses the pressure side of the other blade section when the outer blade section changes by a pitch angle greater than the second pitch angle.
The method according to claim 11, wherein: The first pitch angle is 5 to 15 degrees;
The method according to claim 8, wherein: The first pitch angle is 5 to 15 degrees, and the second pitch angle is 6 to 35 degrees.
The method according to claim 12, wherein:

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