Damping device, blade assembly, wind generating set and damping device manufacturing method

Abstract

The embodiment of the invention provides a vibration reduction device, a blade assembly, a wind generating set and a manufacturing method of the vibration reduction device, the vibration reduction device is used for being installed on a blade of the wind generating set, the vibration reduction device is made of a hard material, is of a curved surface structure and can wrap a part of the periphery of the blade, and a preset gap is formed between the vibration reduction device and the blade; a wind catching cavity is formed in one side of the blade, so that the damping of the blade is increased, and the vibration of the blade is restrained. The damping device made of the hard material is adopted, the damping device forms the wind catching concave cavity, the wind catching concave cavity is large in area, wind resistance can be increased more, the vibration suppression effect is improved, and compared with a wind catching bag and other structures which need to be blown by airflow and are made of the flexible material, the damping device is more convenient to use. The vibration reduction device made of hard materials can play a role in increasing wind resistance when the wind speed is low, and the vibration suppression effect is further improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of wind power generation, and in particular to a vibration reduction device, a blade assembly, a wind power generator set and a manufacturing method of the vibration reduction device. Background Art

[0002] The blades of large impeller units are sometimes stored in large quantities in the yard before being hoisted. Under certain wind conditions (such as high wind speed and wind direction perpendicular to the span direction), the blades will cause first-order vibration in the swing direction. When the vibration amplitude is large, it will cause the blades to touch the ground, causing damage to the blade shape and structure or even scrapping; in addition, long-term and large-scale vibrations will also cause fatigue load damage in this direction. At present, the main solution is to set a mesh sleeve on the blade tip. The blade tip mesh sleeve can change the aerodynamic performance of the blade, produce a turbulent effect on the blade surface, and achieve vibration suppression of the blade. However, the mesh sleeve vibration suppression solution has the disadvantages of being difficult to disassemble, high cost, and cannot be reused. Summary of the invention

[0003] The present disclosure aims to at least solve the problem in the above-mentioned prior art or related technology that blade vibration can easily cause damage to the blade shape and structure or even scrap it, and the existing solution of suppressing vibration by installing a mesh sleeve on the blade has the disadvantages of being difficult to disassemble, high cost, and non-reusable.

[0004] To achieve the above-mentioned purpose, a first aspect embodiment of the present disclosure provides a vibration reduction device for installation on the blades of a wind turbine generator set. The vibration reduction device is made of a hard material and formed into a curved structure. It can wrap around a part of the outer circumference of the blade and be separated from the blade by a predetermined gap to form a wind-catching cavity on one side of the blade, so that the damping of the blade is increased, thereby suppressing the vibration of the blade.

[0005] In some embodiments, multiple outwardly extending corners are formed at the edge of the curved structure, and the vibration reduction device can be connected to the blade through the corners. The corners can be supported on the surface of the blade, and an air inlet is formed between two adjacent corners and the blade to allow air to enter the ventilation cavity.

[0006] In some embodiments, in the length direction of the blade, the vibration reduction device is bent to form a plurality of continuous curved surface structures, and has a plurality of corners arranged at intervals, and an air inlet is formed between two adjacent corners and the blade.

[0007] In some embodiments, an opening is formed at the edge of the curved structure, the opening can be covered on the blade, and there is a gap between the edge of the curved structure and the blade, and the gap forms an air inlet.

[0008] In some embodiments, the vibration reduction device can be wrapped around the pressure side and the suction side of the blade respectively, wherein each curved surface structure located on the pressure side of the blade includes two corners, and each curved surface structure located on the suction side of the blade includes two corners.

[0009] In some embodiments, the vibration reduction device is made of any one of fiberglass, gypsum, and rigid foam.

[0010] In some embodiments, the vibration damping device is made of any one of PP, PET, PA6, PA66, ASA, PPO, PI, and PEEK.

[0011] In some embodiments, a plurality of ventilation holes are provided on the vibration reduction device for adjusting the wind resistance of the vibration reduction device.

[0012] A second aspect of the present disclosure provides a blade assembly, including a blade. The blade assembly also includes a vibration reduction device as described in any one of the above embodiments, and the vibration reduction device is connected to the outer surface of the blade.

[0013] The blade assembly provided in the embodiment of this aspect has the vibration reduction device of any of the above embodiments, and thus has the beneficial effects of any of the above embodiments, which will not be described in detail here.

[0014] In some embodiments, the blade assembly further includes: a connector, which connects the vibration reduction device to the blade and locates the wind-collecting cavity on the suction side of the blade to reduce the velocity of the airflow passing through the suction side of the blade.

[0015] In some embodiments, the wind-enhancing cavity further extends from the suction side of the blade to the pressure side of the blade, so that the flow velocity of the airflow flowing through the pressure side of the blade is reduced and the pressure difference between the pressure side and the suction side is reduced.

[0016] In some embodiments, the blade assembly further includes: a buffer pad disposed between the vibration reduction device and the blade to separate the vibration reduction device and the blade.

[0017] In some embodiments, there are multiple buffer pads, and the multiple buffer pads are spaced apart along the span direction of the blade, and there is a gap between two adjacent buffer pads.

[0018] In some embodiments, the connecting member includes a tying rope, which is fixedly connected to the vibration damping device, so that the vibration damping device can be fixed on the blade, and the vibration damping device is formed into a bag shape with an air inlet on the surface of the blade, and external air flow can enter between the vibration damping device and the blade through the air inlet.

[0019] In some embodiments, the connecting member also includes a tightener connected to the binding rope, and the tightener can adjust the tightness of the binding rope; the two ends of the vibration damping device are respectively wrapped around the pressure side and the suction side of the blade, and two of the corners of the vibration damping device are located on the pressure side of the blade, and the other two corners are located on the suction side of the blade. On each of the pressure side and the suction side, the binding rope is connected to the two corners of the vibration damping device and is wrapped around the circumference of the blade and fixed to prevent the vibration damping device from moving on the blade.

[0020] A third aspect of the present disclosure provides a wind turbine generator set, the wind turbine generator set comprising a blade assembly as described in any one of the above embodiments.

[0021] The wind turbine generator set provided in the embodiment of this aspect has the blade assembly of any of the above embodiments, and thus has the beneficial effects of any of the above embodiments, which will not be described in detail here.

[0022] The fourth aspect embodiment of the present disclosure provides a method for manufacturing a vibration damping device, which is made of a composite material. The method for manufacturing the vibration damping device includes: pultruding the composite material to form a sheet of a preset thickness; connecting multiple sheets and forming them into a curved structure to form the vibration damping device.

[0023] In some embodiments, the step of connecting and molding multiple sheets into a curved structure to form a vibration damping device includes: laying multiple sheets in a mold for forming the vibration damping device, the inner surface of the mold is arched, splicing and laying multiple sheets along the circumferential direction of the mold on the inner surface of the mold, and forming a curved surface after splicing the multiple sheets; heating the mold to a temperature higher than the softening temperature of the sheets to soften the sheets and form a curved body that conforms to the mold; pouring resin into the curved body and curing the resin to form a vibration damping device.

[0024] In some embodiments, the method for manufacturing a vibration damping device further includes: after forming a curved body conforming to the mold and before infusing resin into the curved body and curing the resin, after cooling the mold, arranging a vacuum infusion system.

[0025] In some embodiments, the composite material includes a plastic material and reinforcing fibers.

[0026] In some embodiments, the plastic material includes any one of PP, PET, PA6, PA66, ASA, PPO, PI, and PEEK; the reinforcing fiber includes any one of glass fiber, basalt fiber, aramid fiber, carbon fiber, and synthetic fiber.

[0027] In some embodiments, the thickness of the sheet is from 1 mm to 2 mm.

[0028] In some embodiments, the length of the sheet is from 8m to 15m.

[0029] In some embodiments, the resin poured into the curved body is a thermoplastic resin or a thermosetting resin.

[0030] In some embodiments, each sheet is a straight plate, and the structures of multiple sheets are the same.

[0031] The vibration reduction device provided in the embodiment of this aspect is used to be installed on the blades of a wind turbine generator set. The vibration reduction device is a curved structure made of hard material, and the vibration reduction device can wrap around a part of the outer circumference of the blade and be separated from the blade by a predetermined gap, so that the vibration reduction device can form a wind-catching cavity on one side of the blade. Based on the characteristic that wind resistance is positively correlated with wind speed, a vibration reduction device capable of wind-catching is provided on the blade, so that the damping of the blade is increased under the action of the vibration reduction device, thereby suppressing the vibration of the blade, solving the problem of yard vibration caused by strong winds, and at the same time considering the strength of each component to ensure that each component does not fail under strong wind conditions; further, the vibration reduction device made of hard material is used, and the vibration reduction device itself forms a wind-catching cavity. The larger area of ​​the wind-catching cavity can increase the wind resistance more and improve the vibration suppression effect. In addition, compared with structures such as wind-catching bags made of flexible materials that need to be blown up by airflow, the vibration reduction device made of hard material can increase the wind resistance even when the wind speed is relatively low, further improving the vibration suppression effect.

[0032] Additional aspects and / or advantages of the present general inventive concept will be set forth in part in the following description and in part will be apparent from the description or may be learned through practice of the present general inventive concept. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and other objects and features of the present invention will become more apparent through the following description in conjunction with the accompanying drawings which exemplarily illustrate an example, in which:

[0034] Figure 1 is a schematic diagram of a plurality of vibration reduction devices installed on the trailing edge side of a blade according to a first embodiment of the present invention;

[0035] Figure 2 is a schematic diagram of a plurality of vibration reduction devices installed on the leading edge side of a blade according to a first embodiment of the present invention;

[0036] Figure 3 is a structural schematic diagram of a magnetic attraction component according to an embodiment of the present invention;

[0037] Figure 4 is a structural schematic diagram of a magnetic attraction component according to another embodiment of the present invention;

[0038] Figure 5 is a schematic structural diagram of a vibration reduction device according to a second embodiment of the present invention installed on a blade;

[0039] Figure 6 is a cross-sectional schematic diagram of a vibration reduction device installed on a blade according to a second embodiment of the present invention;

[0040] Figure 7 is a schematic structural diagram of a vibration reduction device according to a third embodiment of the present invention;

[0041] Figure 8 is a cross-sectional schematic diagram of a vibration reduction device installed on a blade according to a third embodiment of the present invention;

[0042] Fig. 9 is a schematic structural diagram of a buffer installed on a blade according to a third embodiment of the present invention; Fig.10 is a flow chart of a method for manufacturing a vibration reduction device according to an embodiment of the present invention;

[0043] Fig.11 is a schematic structural diagram of a sheet formed after a pultrusion step in a method for manufacturing a vibration damping device according to an embodiment of the present invention;

[0044] Fig.12 is a schematic structural diagram of a mold for forming the vibration reduction device according to an embodiment of the present invention;

[0045] Fig.13 is a single vibration direction stall-induced flutter model according to an embodiment of the present invention;

[0046] Fig.14 is an arbitrary vibration direction stall-induced flutter model according to an embodiment of the present invention;

[0047] Fig.15 is a simulation diagram of the effect of a vibration reduction device on a flow field on a blade surface according to an embodiment of the present invention;

[0048] Fig.16 is another simulation diagram of the effect of the vibration reduction device on the flow field on the blade surface according to an embodiment of the present invention.

[0049] Figures 1 to 16 Description of reference numerals:

[0050] 10 vibration damping device, 110 ventilation cavity,

[0051] 20 connectors,

[0052] 30 blades, 310 suction side, 320 pressure side, 330 trailing edge side, 340 leading edge side, 350 air inlet,

[0053] 40 magnetic attraction component, 410 magnetic attraction member, 411 electromagnet, 412 locking pin, 413 sliding member, 4131 accommodating cavity, 4132 opening, 4133 pin hole, 414 remote control signal receiver, 415 battery, 420 matching member, 421 lock buckle, 422 lock hole,

[0054] 50 cushioning pads. DETAILED DESCRIPTION

[0055] The following specific embodiments are provided to help the reader gain a comprehensive understanding of the methods, devices and / or systems described herein. However, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be clear after understanding the disclosure of the present application. For example, the order of operations described herein is only an example and is not limited to those orders set forth herein, but can be changed as will be clear after understanding the disclosure of the present disclosure, except for operations that must occur in a specific order. In addition, for greater clarity and simplicity, descriptions of features known in the art may be omitted.

[0056] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided to illustrate only some of the many possible ways to implement the methods, devices, and / or systems described herein, which will be clear after understanding the disclosure of the present disclosure.

[0057] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more.

[0058] Although terms such as "first", "second", and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions should not be limited by these terms. Instead, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, first component, first region, first layer, or first portion referred to in the examples may also be referred to as the second member, second component, second region, second layer, or second portion.

[0059] In the specification, when an element such as a layer, a region or a substrate is described as being “on”, “connected to” or “coupled to” another element, the element may be directly “on”, “connected to” or “coupled to” another element, or one or more other elements may be present therebetween. Conversely, when an element is described as being “directly on”, “directly connected to” or “directly coupled to” another element, other elements may not be present therebetween.

[0060] The terms used herein are only used to describe various examples and are not intended to limit the disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "comprise", "include" and "have" indicate the presence of the described features, quantities, operations, components, elements and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements and / or combinations thereof. The term "plurality" represents any number of two and more than two.

[0061] The definitions of directional terms such as "upper", "lower", "top" and "bottom" in the present disclosure are all based on the directional definitions when the product is in normal use and placed upright.

[0062] Unless otherwise defined, all terms used herein, including technical terms and scientific terms, have the same meanings as those generally understood by those skilled in the art to which the present disclosure belongs after understanding the present disclosure. Unless explicitly defined as such herein, terms such as those defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art and the present disclosure, and should not be interpreted in an idealized or overly formal manner.

[0063] Furthermore, in the description of examples, when it is considered that a detailed description of a well-known related structure or function would cause vague interpretation of the present disclosure, such a detailed description will be omitted.

[0064] The following will be combined Figures 1 to 16 The vibration reduction device 10, the blade assembly, the wind turbine generator set and the manufacturing method of the vibration reduction device 10 provided in the embodiments of the present disclosure are introduced.

[0065] like Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, a first aspect embodiment of the present disclosure provides a vibration reduction device 10 for installation on a blade 30 of a wind turbine generator set. The vibration reduction device 10 is made of a hard material and is formed into a curved structure. It can wrap around a portion of the periphery of the blade 30 and be separated from the blade 30 by a predetermined gap to form a wind-catching cavity 110 on one side of the blade 30, so that the damping of the blade 30 is increased, thereby suppressing the vibration of the blade 30.

[0066] The vibration reduction device 10 provided in the embodiment of the present invention is used to be installed on the blade 30 of the wind turbine generator set. The vibration reduction device 10 is a curved surface structure made of hard material, and the vibration reduction device 10 can wrap around a part of the outer periphery of the blade 30 and be separated from the blade 30 by a predetermined gap, so that the vibration reduction device 10 can form a wind-catching cavity 110 on one side of the blade 30. Based on the characteristic that wind resistance is positively correlated with wind speed, the vibration reduction device 10 capable of wind-catching is arranged on the blade 30, so that the damping of the blade 30 is increased under the action of the vibration reduction device 10, thereby suppressing the blade 30 from vibrating. The vibration of the storage yard caused by strong winds is solved, and the strength of each component is taken into consideration to ensure that each component does not fail under strong wind conditions; further, a vibration reduction device 10 made of hard material is adopted, and the vibration reduction device 10 itself forms a wind-shaking cavity 110. The large area of ​​the wind-shaking cavity 110 can increase the wind resistance more and improve the vibration suppression effect. Compared with structures such as wind-shaking bags made of flexible materials that need to be blown by airflow, the vibration reduction device 10 made of hard materials can increase the wind resistance when the wind speed is relatively low, thereby further improving the vibration suppression effect.

[0067] In the first embodiment of the present disclosure, Figure 1 and Figure 2 As shown, multiple corners extending outward are formed at the edge of the curved structure, and the vibration reduction device 10 can be connected to the blade 30 through the corners. The corners can be supported on the surface of the blade 30, and an air inlet 350 is formed between two adjacent corners and the blade 30 for airflow to enter the ventilation cavity 110. In this way, the vibration reduction device 10 is supported on the surface of the blade 30 through multiple corners formed at the edge of the curved structure, and an air inlet 350 is formed between two adjacent corners and the blade 30. The airflow can be blown into the ventilation cavity 110 through the air inlet 350. The ventilation cavity 110 can gather wind and has a large ventilation area, which has a good wind blocking effect.

[0068] In some embodiments, the vibration reduction device 10 can be wrapped around the pressure side 320 and the suction side 310 of the blade 30 respectively, so that the vibration reduction device 10 can block the airflow on the suction side 310 and the pressure side 320 of the blade 30, so that the airflow can form vortices on the suction side 310 and the pressure side 320 of the blade 30, reduce the flow rate of the airflow, thereby balancing the pressure on the suction side 310 and the pressure side 320 of the blade 30, and reducing the pressure difference between the suction side 310 and the pressure side 320 of the blade 30, so as to achieve the purpose of suppressing the vibration of the blade 30. Among them, each curved surface structure located on the pressure side 320 of the blade 30 includes two corners, and the two corners are supported on the pressure side 320 of the blade 30 to form an air inlet 350 together with the blade 30, and each curved surface structure located on the suction side 310 of the blade 30 includes two corners, and the two corners are supported on the suction side 310 of the blade 30 to form an air inlet 350 together with the blade 30.

[0069] In some embodiments, the vibration reduction device 10 is made of any one of glass fiber reinforced plastics, gypsum, and rigid foam. The vibration reduction device 10 can be formed by vacuum infusion, molding, hand lay-up, and other processes.

[0070] In some embodiments, the vibration damping device 10 is made of any one of PP, PET, PA6, PA66, ASA, PPO, PI, and PEEK. The vibration damping device 10 can be formed by vacuum infusion, molding, hand lay-up, pultrusion, and other processes. The above materials are all thermoplastic resins, and are particularly suitable for forming the vibration damping device 10 by pultrusion. The thermoplastic resin is capable of conforming to the shape during the heating process. The sheet is heated to conform to the shape, and then the resin is infused to bond the sheet as a whole to form the vibration damping device 10, thereby effectively improving the shape accuracy of the vibration damping device 10, so that the vibration damping device 10 and the blade 30 are more conformable.

[0071] In some embodiments, a buffer pad 50 is provided on the side of the vibration reduction device 10 facing the blade 30 and in contact with the blade 30. The buffer pad 50 can isolate the blade 30 from the vibration reduction device 10, prevent the blade 30 from being scratched or hit by the vibration reduction device 10, and protect the blade 30.

[0072] Further, in some embodiments, as an example, optionally, the buffer pad 50 can be adhered to the inner surface of the vibration damping device 10, and the vibration damping device 10 can be bundled to the blade 30 through the connecting member 20 to achieve fixation of the vibration damping device 10; or, the buffer pad 50 can be adhered to the blade 30, and the vibration damping device 10 can be bundled to the blade 30 through the connecting member 20 to achieve fixation between the vibration damping device 10 and the blade 30; or, one side of the buffer pad 50 is adhered to the inner surface of the vibration damping device 10, and the other side of the vibration damping device 10 is adhered to the blade 30 to achieve fixation between the vibration damping device 10 and the blade 30.

[0073] In some embodiments, a plurality of ventilation holes are provided on the vibration reduction device 10 to adjust the wind resistance of the vibration reduction device 10. The ventilation holes 120 are easy to process and can be directly punched on the vibration reduction device 10. The wind resistance of the vibration reduction device 10 can be reduced through a simple process, and the connection member 20 can be prevented from being broken due to excessive resistance of the vibration reduction device 10, and the connection member 20 can be prevented from exerting excessive pressure on the local surface of the blade 30, causing damage to the surface of the blade 30.

[0074] In the second embodiment of the present disclosure, different from the first embodiment, as Figure 5 and Figure 6As shown, the vibration damping device 10 in the first embodiment can be extended to form multiple air inlets 350 on one vibration damping device 10. Specifically, in the length direction of the blade 30, the vibration damping device 10 is bent to form multiple continuous curved surface structures, and has multiple corners arranged at intervals, and an air inlet 350 is formed between two adjacent corners and the blade 30. In this way, each vibration damping device 10 can form multiple air inlets 350. On the one hand, it can increase the wind blocking area and improve the wind blocking effect; on the other hand, compared with the structure in which each vibration damping device 10 in the multiple vibration damping devices 10 needs to be installed on the blade 30 separately, the vibration damping device 10 with multiple continuous curved surface structures installed on the blade 30 has a larger wind blocking area and a better wind blocking effect. One vibration damping device 10 can achieve the wind blocking and vibration suppression effects of multiple vibration damping devices 10 in the first embodiment. Further, as an example, optionally, the connection between the blade 30 and the vibration damping device 10 can be achieved by wrapping a tying rope around and covering the outer periphery of the vibration damping device 10, thereby simplifying the connection structure between the blade 30 and the vibration damping device 10 and facilitating the assembly between the vibration damping device 10 and the blade 30. Of course, tying ropes can also be provided at both ends and multiple locations in the middle of the vibration damping device 10, and the multiple locations can be tied and fixed.

[0075] In the third embodiment of the present disclosure, different from the first embodiment, as Figure 7 and Figure 8 As shown, the vibration damping device 10 may also be provided without a corner, that is, one end of the vibration damping device 10 is in an open shape, and the vibration damping device 10 is covered on the blades at the opening, and the opening is located between the blades with a gap to form an air inlet 350. In this way, the cross-section of the vibration damping device 10 at various locations in the length direction is the same, the structure of the vibration damping device 10 is simpler, the processing technology is also simple, and the processing and production are convenient.

[0076] Further, in some embodiments, optionally, as Fig. 9 As shown, the length of the buffer pad 50 extends along the chord direction of the blade 30, and the buffer pad 50 can cover a portion of the suction side 310 and the pressure side 320 of the blade 30. The buffer pad 50 is installed between the blade 30 and the vibration reduction device 10. The buffer pad 50 can support the vibration reduction device 10 so that the vibration reduction device 10 does not completely fit the blade 30; a plurality of buffer pads 50 are spaced apart along the span direction of the blade 30, and there is a gap between two adjacent buffer pads 50, and wind can pass through the gap, so that a plurality of wind cavities are formed between the vibration reduction device 10 and the blade 30, and the wind cavities have a better wind cavitation effect, which can better suppress the vibration of the blade 30.

[0077] A second aspect of the present disclosure provides a blade assembly, including a blade 30 . The blade assembly also includes a vibration reduction device 10 as described in any one of the above embodiments, and the vibration reduction device 10 is connected to the outer surface of the blade 30 .

[0078] The blade assembly provided in the embodiment of this aspect has the vibration reduction device 10 of any of the above embodiments, and thus has the beneficial effects of any of the above embodiments, which will not be described in detail here.

[0079] In some embodiments, the vibration reduction device 10 is mounted on the leading edge side 340 and / or the trailing edge side 330 of the blade 30. Figure 2 As shown, the vibration reduction device 10 can be arranged on the leading edge side 340 of the blade 30, in which case the air inlet 350 faces the trailing edge side 330; Figure 1 As shown, the vibration damping device 10 can also be arranged on the trailing edge side 330 of the blade 30. In this state, the air inlet 350 faces the leading edge side 340. Of course, the vibration damping device 10 can also be arranged on both the leading edge side 340 and the trailing edge side 330 of the blade 30. The vibration damping device 10 arranged on the leading edge side 340 of the blade 30 and the vibration damping device 10 on the trailing edge side 330 are alternately arranged in the span direction of the blade 30, so that the vibration damping effect can be exerted no matter from which direction the external wind blows.

[0080] It is worth noting that, since the relationship between wind resistance and wind speed is a quadratic positive correlation, the greater the wind speed, the greater the wind force on the vibration reduction device 10, the greater the resistance generated, and the greater the increased damping of the blade 30 system. Therefore, by providing the vibration reduction device 10, the wind resistance can be efficiently utilized to increase the damping of the blade 30, thereby avoiding stall-induced flutter of the blade 30.

[0081] In some embodiments, Figure 1 and Figure 2 As shown, the blade assembly also includes: a connecting member 20, which connects the vibration reduction device 10 to the blade 30 and locates the wind-absorbing cavity 110 on the suction side 310 of the blade 30 to reduce the flow rate of the airflow flowing through the suction side 310 of the blade 30.

[0082] In these embodiments, the vibration reduction device 10 is connected to the blade 30 through the connecting member 20, which is conducive to the subsequent removal of the vibration reduction device 10 from the blade 30 when the vibration reduction device 10 is not needed. Further, a wind-shaking cavity 110 is formed on the suction side 310 of the blade 30, which can block the airflow on the suction side 310 of the blade 30, so that the airflow forms a vortex on the suction side 310 of the blade 30, reducing the flow rate of the airflow, thereby increasing the pressure on the suction side 310 of the blade 30, reducing the pressure difference between the suction side 310 and the pressure side 320 of the blade 30, so that the lift of the blade 30 is reduced, the system damping is increased, and the vibration of the blade 30 is suppressed.

[0083] Generally, when the airflow flows through the periphery of the blade 30, the airflow velocity on the suction side 310 of the blade 30 is greater than the airflow velocity on the pressure side 320 of the blade 30. According to the Bernoulli equation, the greater the gas velocity, the smaller the pressure. Therefore, the pressure on the pressure side 320 of the blade 30 is greater, and there is a certain pressure difference between the suction side 310 and the pressure side 320, so that the blade 30 obtains lift. In some embodiments, the wind-driving cavity 110 also extends from the suction side 310 of the blade 30 to the pressure side 320 of the blade 30, so that the velocity of the airflow flowing through the pressure side 320 of the blade 30 is reduced, and the pressure difference between the pressure side 320 and the suction side 310 is reduced.

[0084] In these embodiments, the ventilation cavity 110 is arranged on the suction side 310 of the blade 30 and the pressure side 320 of the blade 30, which can block the airflow on the suction side 310 and the pressure side 320 of the blade 30, so that the airflow can form vortices on the suction side 310 and the pressure side 320 of the blade 30, thereby reducing the flow rate of the airflow, thereby balancing the pressure on the suction side 310 and the pressure side 320 of the blade 30, reducing the pressure difference between the suction side 310 and the pressure side 320 of the blade 30, and achieving the purpose of suppressing the vibration of the blade 30.

[0085] According to the Bernoulli equation, the greater the gas flow rate, the smaller the pressure. The air flow speed on the pressure side 320 of the blade 30 surface is slow and the pressure is high, while the pressure on the suction side 310 is low, which will generate a pressure from the pressure side 320 toward the suction side 310, causing the blade 30 to swing in one direction; and when the wind conditions change, there is a probability that the pressure on both sides will shift. If the wind changes periodically, it will cause the blade 30 to swing frequently and produce vortex-induced vibration. By reducing the airflow velocity flowing through the surface of the blade 30, the pressure difference on both sides of the blade 30 can be reduced, thereby reducing vortex-induced vibration and suppressing the vibration of the blade 30.

[0086] It can be understood that after the external airflow flows through the blade 30 and enters the vent cavity 110, a negative pressure area will be formed on the side of the vent cavity 110 away from the blade 30, and a pressure difference will be formed on both sides of the vibration reduction device 10, so that the vibration reduction device 10 can apply a pressure difference resistance to the blade 30 that is roughly consistent with the vibration direction of the blade 30, thereby suppressing the vibration of the blade 30.

[0087] In some embodiments, Figure 1 and Figure 2As shown, the connecting member 20 includes a tying rope, which is fixedly connected to the vibration damping device 10, and can fix the vibration damping device 10 on the blade 30, and make the vibration damping device 10 form a bag with an air inlet 350 on the surface of the blade 30, and the external airflow can enter between the vibration damping device 10 and the blade 30 through the air inlet 350. The vibration damping device 10 is tied to the blade 30 by the tying rope, which facilitates the connection between the blade 30 and the vibration damping device 10; the tying rope is selected as the connecting member 20, which has low cost, can be tied to the surface of the blade 30, and is fastened and fixed to the blade 30 by knotting or hooking, and the connection between the blade 30 is simple. In some embodiments, the connecting member 20 also includes a tightener connected to the binding rope, which can adjust the tightness of the binding rope, so as to better adjust the tightness of the binding rope covering the vibration damping device 10 and the blade 30, so that the fixation between the vibration damping device 10 and the blade 30 is more secure; the two ends of the vibration damping device 10 are respectively covered on the pressure side 320 and the suction side 310 of the blade 30, and two of the corners of the vibration damping device 10 are located on the pressure side 320 of the blade 30, and the other two corners are located on the suction side 310 of the blade 30, so that an air inlet 350 can be formed on the suction side 310 and the pressure side 320 of the blade 30, and a wind-shaking cavity 110 can be formed on the suction side 310 and the pressure side 320 of the blade 30, thereby reducing the flow rate of the airflow, increasing the system damping, and thereby suppressing the vibration of the blade 30. On each side of the pressure side 320 and the suction side 310 , the tying rope is connected to two corners of the vibration damping device 10 , so that the tying rope is firmly connected to the vibration damping device 10 , and is wrapped around the circumference of the blade 30 to prevent the vibration damping device 10 from moving on the blade 30 , thereby fixing the vibration damping device 10 .

[0088] Further, in order to facilitate the removal of the vibration damping device 10 from the blade 30 and recycling, in some embodiments, the blade assembly further includes a magnetic suction assembly 40, wherein the magnetic suction assembly 40 includes a magnetic suction member 410 and a matching member 420, there is a disconnection between the connecting member 20 and the vibration damping device 10 or there is a disconnection on the connecting member 20, the magnetic suction member 410 is connected to one end of the disconnection, and the matching member 420 is connected to the other end of the disconnection, the magnetic suction member 410 can lock the matching member 420 by magnetic suction force, so that the vibration damping device 10 can be installed on the blade 30, and the magnetic suction member 410 can also release the matching member 420, so that the vibration damping device 10 can be removed from the blade 30. In this way, the vibration damping device 10 is installed on the blade 30 through the connecting member 20 and the magnetic suction assembly 40, and the vibration damping device 10 can also be removed from the blade 30 by controlling the magnetic suction assembly 40, which facilitates the removal and recycling of the vibration damping device 10. The magnetic component 40 includes a magnetic component 410 and a matching component 420. There is a disconnection between the connecting component 20 and the vibration damping device 10. The magnetic component 410 is connected to one of the connecting component 20 and the vibration damping device 10, and the matching component 420 is connected to the other of the connecting component 20 and the vibration damping device 10. The magnetic component 410 can lock the matching component 420 through magnetic attraction so that the vibration damping device 10 can be installed on the blade 30. The magnetic component 410 can also release the matching component 420, so that the connection between the connecting component 20 and the vibration damping device 10 is disconnected, thereby allowing the vibration damping device 10 to be removed from the blade 30. Alternatively, there is a disconnection on the connecting member 20, the magnetic member 410 is connected to one end of the disconnection on the connecting member 20, and the matching member 420 is connected to the other end of the disconnection on the connecting member 20. The magnetic member 410 can lock the matching member 420 by magnetic attraction so that the vibration damping device 10 can be installed on the blade 30. The magnetic member 410 can also release the matching member 420, so that the connection between the disconnection points of the connecting member 20 is disconnected, thereby allowing the vibration damping device 10 to be removed from the blade 30.

[0089] Furthermore, in some embodiments, the vibration reduction device 10 further includes a controller, and the controller can control the magnetic attraction member 410 to lock with the matching member 420 or release the matching member 420 through magnetic force.

[0090] In these embodiments, the controller is used to control the magnetic member 410 to lock or release the matching member 420, which is convenient for user operation. It is understandable that the controller can be a remote control device that can be used on the ground to remotely control the magnetic member 410, so that when the vibration reduction device 10 is no longer needed, the controller can be controlled on the ground to disconnect the attraction between the magnetic member 410 and the matching member 420, so that the vibration reduction device 10 is separated from the blade 30 and falls freely, realizing the automatic disassembly of the vibration reduction device 10, and there is no need to approach the blade 30 to disassemble the vibration reduction device 10, which is convenient for operation and avoids the danger of high-altitude operation.

[0091] In some embodiments, Figure 3 As shown, the magnetic attraction member 410 includes an electromagnet 411; the matching member 420 includes the electromagnet 411 or a magnetic material; wherein the controller can control the electromagnet 411 to be energized and de-energized, so that it has magnetism and loses magnetism. When the electromagnet 411 is energized, it can have a magnetic attraction force, so that it can be connected to the matching member 420 through magnetic attraction. When the electromagnet 411 is de-energized, it will lose the magnetic attraction force, thereby releasing the matching member 420, and the two can be separated from each other. By controlling the energization and de-energization of the electromagnet 411, the connection or disconnection between the magnetic attraction member 410 and the matching member 420 can be controlled, which is convenient for the user to operate, so that the operation of installing the vibration reduction device 10 on the blade 30 and the operation of removing it from the blade 30 are simple and convenient.

[0092] In some embodiments, the magnetic member 410 and the matching member 420 may both be permanent magnets, and the magnetic assembly 40 further includes a driver, which may be a motor, the output shaft of which is connected to the magnetic member 410, thereby driving the magnetic member 410 or the matching member 420 to move or rotate. The controller can control the operation of the driver to control the driver to drive one of the magnetic member 410 and the matching member 420 to move, so that the magnetic member 410 and the matching member 420 have opposite magnetic poles facing each other or like magnetic poles facing each other, so as to attract or repel each other magnetically.

[0093] In these embodiments, when the vibration damping device 10 is installed on the blade 30, the opposite magnetic poles of the magnetic element 410 and the matching element 420 face each other, so that the magnetic element 410 and the matching element 420 attract each other, thereby connecting the disconnection between the connecting member 20 and the vibration damping device 10, or connecting the disconnection of the connecting member 20, so that the vibration damping device 10 can be installed on the blade 30; further, when the vibration damping device 10 needs to be disassembled, the driver is used to control the magnetic element 410 or the matching element 420 to flip, so that the like magnetic poles of the magnetic element 410 and the matching element 420 face each other, the magnetic element 410 and the matching element 420 repel each other and separate from each other, thereby separating the disconnection between the connecting member 20 and the vibration damping device 10, or separating the disconnection of the connecting member 20, and the vibration damping device 10 is detached from the blade 30, thereby realizing the automatic disassembly of the vibration damping device 10. Alternatively, when it is necessary to disassemble the vibration damping device 10, the magnetic component 410 or the matching component 420 can be controlled to move a certain distance so that the magnetic component 410 and the matching component 420 cannot attract each other. Similarly, the disconnection between the connecting component 20 and the vibration damping device 10 can be separated, or the disconnection of the connecting component 20 can be separated, and the vibration damping device 10 can be detached from the blade 30, thereby realizing automatic disassembly of the vibration damping device 10.

[0094] In another specific embodiment of the present invention, Figure 4As shown, the magnetic attraction member 410 includes an electromagnet 411, a locking pin 412 and a sliding member 413. The sliding member 413 is arranged below the electromagnet 411. The middle part of the sliding member 413 has a accommodating cavity 4131. The sliding member 413 is provided with a pin hole 4133. The locking pin 412 is fixedly connected to the electromagnet 411 and can extend into the accommodating cavity 4131 through the pin hole 4133. The matching member 420 includes a locking buckle 421. The locking buckle 421 can be inserted into the accommodating cavity 4131, and the locking pin 412 can be inserted into the locking buckle 421. When the magnetic attraction member 410 and the matching member 420 need to be locked, the lock buckle 421 is installed in the accommodating cavity 4131 and aligned with the lock pin 412 when the electromagnet 411 is de-energized. The electromagnet 411 is energized to attract the sliding member 413, so that the sliding member 413 fits the electromagnet 411, so that the lock pin 412 is inserted into the lock buckle 421, and the lock buckle 421 is restricted in the accommodating cavity 4131 and cannot be withdrawn from the accommodating cavity 4131. When the electromagnet 411 is de-energized, the sliding member 413 can be released, so that the sliding member 413 is separated from the electromagnet 411, so that the lock pin 412 is separated from the lock buckle 421, and the lock buckle 421 can be withdrawn from the accommodating cavity 4131.

[0095] In these embodiments, a specific structural embodiment of the magnetic suction component 40 is specifically given, the magnetic suction component 410 includes an electromagnet 411, a locking pin 412 and a sliding component 413, the sliding component 413 is provided with a pin hole 4133, the locking pin 412 is fixedly connected to the electromagnet 411, and can extend into the accommodating cavity 4131 through the pin hole 4133, the cooperation between the locking pin 412 and the pin hole 4133 can play a guiding role, guiding the movement of the sliding component 413 relative to the electromagnet 411, and preventing the movement and deviation of the sliding component 413; when it is necessary to lock the magnetic suction component 410 and the matching component 420, the lock buckle 421 of the matching component 420 is inserted into the accommodating cavity 4131 and the locking pin 412 is inserted into the lock buckle 421, and then the electromagnet 411 is electrically attracted to the sliding component 413, so that the matching component 420 is fixed by the locking pin 412 and the sliding component 413.

[0096] In some embodiments, an opening 4132 is provided on the side wall of the accommodating cavity 4131, and the lock buckle 421 can enter or move out of the accommodating cavity 4131 through the opening 4132. The lock buckle 421 is provided with a lock hole 422, and the lock pin 412 can be inserted into the pin hole 4133. The locking connection between the magnetic element 410 and the matching element 420 is achieved by inserting the lock pin 412 into the lock buckle 421. Compared with the case where the magnetic element 410 and the matching element 420 are connected by magnetic attraction, the connection force is tighter and is not easy to be broken away due to excessive wind force. Furthermore, when the vibration damping device 10 is installed on the blade 30, when the electromagnet 411 is de-energized, the lock buckle 421 is inserted into the accommodating cavity 4131 of the sliding member 413 and aligned with the lock pin 412, and then the electromagnet 411 is electrically attracted to the sliding member 413 so that the sliding member 413 fits the electromagnet 411. In this state, the lock pin 412 is inserted into the lock buckle 421, and the magnetic member 410 and the matching member 420 are connected; and when the vibration damping device 10 needs to be disassembled, the electromagnet 411 is controlled to be de-energized to release the sliding member 413, so that the sliding member 413 is separated from the electromagnet 411, and the restriction of the sliding member 413 on the matching member 420 is released, so that the matching member 420 can be freed from the restriction of the lock pin 412, thereby realizing the separation of the matching member 420 from the magnetic member 410.

[0097] Furthermore, in some embodiments, the magnetic attraction member 410 further includes a guide rail, and the sliding member 413 can move along the rail, further limiting the movement path of the sliding member 413 .

[0098] Furthermore, a stopper is provided at one end of the accommodating cavity 4131 of the locking pin 412 into which the sliding member 413 is inserted, so as to limit the maximum displacement of the sliding member 413 relative to the locking pin 412, so that the sliding member 413 and the locking pin 412 will not separate, and the sliding member 413, the locking pin 412, and the electromagnet 411 are all connected together. As an example, optionally, the stopper can be a protrusion provided at one end of the locking pin 412 and protruding toward the outer periphery, and the width of the protrusion is greater than the width of the pin hole 4133, so as to prevent the protrusion from sliding out of the pin hole 4133, thereby preventing the sliding member 413 from sliding out of the locking pin 412. In addition, the locking pin 412 can be provided with an external thread, and the stopper can be a nut threadedly connected to the locking pin 412.

[0099] Furthermore, the magnetic attraction member 410 may also include a shell, in which the electromagnet 411, the locking pin 412 and the sliding member 413 are all arranged. The electromagnet 411 is fixed to the upper part of the shell, and the sliding member 413 is supported by the bottom wall of the shell. In this way, the sliding member 413 can also be limited by limiting the height of the shell, so that the sliding member 413 and the locking pin 412 will not separate.

[0100] In some embodiments, Figure 4As shown, the magnetic attraction component 40 also includes a battery 415 and a remote control signal receiver 414. The battery 415 can be electrically connected to the electromagnet 411; the remote control signal receiver 414 can receive a control signal from the controller and electrically connect or disconnect the battery 415 from the electromagnet 411 according to the control signal.

[0101] In these embodiments, the battery 415 can supply power to the electromagnet 411 and the remote control signal receiver 414 , and the remote control signal receiver 414 can control the electrical connection or disconnection between the battery 415 and the electromagnet 411 according to the control signal sent by the controller, thereby controlling the magnetic attraction of the electromagnet 411 .

[0102] The lock catch 421 and the magnetic member 410 can be disassembled only when the electromagnet 411 is separated from the sliding member 413 and the gap between the end of the lock pin 412 and the sliding member 413 is sufficient to allow the lock catch 421 to withdraw outward. Therefore, in order to facilitate the smooth withdrawal of the lock catch 421, when the electromagnet 411 loses power, the sliding member 413 can move in a direction away from the electromagnet 411. As an optional solution, the separation between the electromagnet 411 and the sliding member 413 can be achieved by at least one of gravity, magnetic repulsion, and spring thrust. Specifically, firstly, the sliding member 413 is arranged below the electromagnet 411, and the electromagnet 411 is fixed. After the electromagnet 411 is energized, the magnetic attraction force applied to the sliding member 413 by the electromagnet 411 can overcome the gravity of the sliding member 413 and thus be adsorbed together with the sliding member 413. When the electromagnet 411 loses power, the sliding member 413 moves downward under the action of gravity and separates from the electromagnet 411, thereby allowing the lock 421 to withdraw from the accommodating cavity 4131 of the sliding member 413; secondly, the sliding member 413 can also be set as a permanent magnet or an electromagnet 411. When the electromagnet 411 is energized, it can face the opposite magnetic poles of the sliding member 413, and the magnetic attraction is controlled. The magnetic poles of the control electromagnet 411 can make the sliding member 413 and the like magnetic poles of the electromagnet 411 face each other, so that the two repel each other. The sliding member 413 moves away from the electromagnet 411 under the action of the magnetic repulsion and is separated from the electromagnet 411; thirdly, a spring is arranged between the sliding member 413 and the electromagnet 411, and the electromagnet 411 is fixed. After the electromagnet 411 is energized, the magnetic attraction force applied to the sliding member 413 by the electromagnet 411 can overcome the elastic force of the spring and be adsorbed together with the sliding member 413. The spring is compressed. When the electromagnet 411 loses power, the sliding member 413 moves away from the electromagnet 411 under the action of the elastic force of the spring and is separated from the electromagnet 411.

[0103] In some embodiments, Figure 1 , Figure 2 As shown, the connecting member 20 includes a plurality of tying ropes, such as Figure 2As shown, each binding rope is provided with at least one breaking point, and there are multiple magnetic suction components 40, which are respectively provided at each breaking point.

[0104] In these embodiments, a binding rope is selected as the connecting member 20. The binding rope has low cost and can be tied to the surface of the blade 30. It is fastened and fixed to the blade 30 by knotting or hooking, and the connection between the blade 30 is simple. A set of magnetic components 40 is provided at both ends of each disconnection, so that the disconnection of the binding rope can be connected by the magnetic components 40, which does not affect the bundling function of the binding rope. When the vibration reduction device 10 needs to be removed, the magnetic component 410 and the matching component 420 of the magnetic component 40 are separated to form a break on the binding rope, so that the vibration reduction device 10 can be separated from the blade 30. It can be understood that each binding rope can also have two, three or even more disconnections, as long as a set of magnetic components 40 is provided at each disconnection to connect the two disconnected ends.

[0105] In some embodiments, the blade assembly further includes: a protective plate, which is disposed at least one of between the vibration reduction device 10 and the trailing edge of the blade 30, between the connecting member 20 and the blade 30, and between the magnetic member 410 and / or the matching member 420 and the blade 30. The protective plate can isolate the blade 30 from the vibration reduction device 10, the connecting member 20, the magnetic member 410, and the matching member 420, thereby preventing the blade 30 from being scratched or impacted, and plays a role in protecting the blade 30.

[0106] In some embodiments, the protective plate is provided with a through hole, and the connector 20 passes through the through hole and fastens the protective plate to the blade 30. The protective plate is tightened on the blade 30 by the connector 20, which plays a role in fixing the position of the protective plate and facilitates the fixing of the protective plate.

[0107] In some embodiments, the vibration reduction device 10 is installed in the range of 85% to 95% in the span direction of the blade 30. That is, the installation range of the vibration reduction device 10 is in the range of 85% to 95% from the blade root to the blade 30. On the one hand, based on the characteristic that wind resistance is positively correlated with wind speed, the vibration reduction device 10 is installed in the range close to the blade tip, which can utilize the characteristic of high drag coefficient in the range close to the blade tip to solve the yard vibration problem caused by strong wind in the wind direction from the leading edge to the trailing edge and from the trailing edge to the leading edge; in addition, the installation range is in the range of 85% to 95% from the blade root to the blade 30, which can also avoid interference with aerodynamic accessories installed on the blade 30, such as vortex generators.

[0108] In some embodiments, the vibration reduction device 10 is installed at one end near the tip of the blade 30, and the distance between the vibration reduction device 10 and the blade tip is greater than or equal to 2m and less than or equal to 10m. Within this range, on the one hand, the range within 2m on one side near the tip of the blade 30 can be avoided. Generally speaking, the inner chord length of the blade 30 2m from the tip is too small, which is not convenient for installing the vibration reduction device 10. Therefore, the vibration reduction device 10 is installed on the blade 30 outside 2m from the tip and installed inward in sequence; on the other hand, based on the characteristics that wind resistance is positively correlated with wind speed, the vibration reduction device 10 is installed within 10m near the tip of the blade. The characteristics of the high drag coefficient within the range near the tip of the blade can be used to solve the yard vibration problem caused by strong winds in the wind direction from the leading edge to the trailing edge and from the trailing edge to the leading edge. At the same time, the strength of each component is considered to ensure that each component does not fail under strong wind conditions; in addition, the installation range is from 2m to 10m from the tip of the blade, which can also avoid interference with aerodynamic accessories installed on the blade 30, such as vortex generators.

[0109] In some embodiments, the vibration reduction device 10 partially overlaps with the blade 30, and can cover 50% to 80% of the chord width of the blade 30. That is, the vibration reduction device 10 can cover at least a portion of the chord width of the blade 30, that is, it overlaps with at least a portion of the blade 30, for example, covering 50% to 80% of the chord length of the blade 30. Within this range, it covers a sufficient chord width of the blade 30, solves the problem of yard vibration caused by strong winds in the wind direction from the leading edge to the trailing edge and from the trailing edge to the leading edge, and can effectively play a vibration suppression effect, and will not be difficult to be blown up due to the excessive chord width of the blade 30 covered by the vibration reduction device 10. In some embodiments, there are multiple vibration reduction devices 10, which are arranged at intervals along the span direction of the blade 30, and the distance between two adjacent vibration reduction devices 10 is 20cm-50cm. Such an arrangement can avoid mutual interference between two adjacent vibration reduction devices 10, and will not affect the vibration suppression effect by being too far apart.

[0110] Optionally, in practical applications, a single vibration reduction device 10 may be installed on the blade 30, or 3 to 6 vibration reduction devices 10 may be installed sequentially from 2 m from the blade tip to the blade root, such as Figure 1 , Figure 2 shown.

[0111] In some embodiments, the width of each vibration reduction device 10 in the span direction of the blade 30 is 1m-4m. Within this range, it has a sufficient length to effectively suppress vibration, but does not cause excessive resistance due to the excessive width of a single vibration reduction device 10 in the span direction of the blade 30, which may easily break the connector 20.

[0112] In some embodiments, the laying width of the vibration reduction device 10 in the span direction of the blade 30 is 8m to 10m. Within this range, it has a sufficient length to effectively suppress vibration, but does not interfere with other components on the blade 30 due to the excessive width of the vibration reduction device 10 in the span direction of the blade 30.

[0113] In order to better understand the present invention, the principle of stall-induced flutter and the mechanism by which the vibration suppression device of the present invention can suppress vibration are briefly analyzed below.

[0114] Fig.13 It is a stall-induced flutter model with a single vibration direction. In this simplified model, the airfoil vibrates in a single degree of freedom along the direction perpendicular to the incoming flow.

[0115] According to the simplified single-degree-of-freedom model, vibration causes periodic changes in the angle of attack, which in turn causes periodic changes in the aerodynamic force. When the direction of the increase in aerodynamic force is the same as the direction of vibration, or in other words, there is a phase difference between the aerodynamic force and the vibration displacement within a vibration cycle, the aerodynamic force does positive work within a vibration cycle, resulting in the accumulation of total system energy, and the mechanical energy of the incoming flow is converted into the elastic potential energy of the bending deformation of the blade 30, resulting in a tendency for the deformation of the blade 30 to increase, which ultimately manifests as a self-excited vibration with a continuously increasing deflection of the blade 30. For example, at a large angle of attack, the blade 30 vibrates upward, and the angle of attack α 0 Reduce lift coefficient C L Increase, C L If the vibration direction component increases and its direction is the same as the vibration direction, the vibration will tend to increase.

[0116] According to the technical solution of the present invention, by providing a vibration suppression device, the pressure difference between the pressure side 320 and the suction side 310 of the blade 30 can be reduced, thereby reducing the lift and further reducing the energy that excites the flutter of the blade 30.

[0117] By generalizing the previous single-degree-of-freedom simplified model, the stall-induced flutter model of the airfoil in any vibration direction x can be obtained. Fig.14 The stall-induced flutter model of the airfoil in any vibration direction is shown. Since the aerodynamic forces in other directions do not work on the vibration, only the aerodynamic resultant force of the blade 30 airfoil in the vibration direction is discussed below. The aerodynamic resultant force Fx and F 0 It can be expressed by the following formula (2) and formula (3) respectively:

[0118]

[0119]

[0120] in,

[0121]

[0122] Based on equations (2) and (3), the aerodynamic force F under dynamic conditions is x On the aerodynamic force F in steady state 0 Perform linearization at the equilibrium point x=0, that is, perform a first-order Taylor expansion according to the following formula (4), and obtain the equivalent damping coefficient η of the model, which can be expressed by the following formula (5).

[0123] F x ≈F 0 -ηx Formula (4)

[0124]

[0125] Among them, in the above formula (2), formula (3), formula (4), formula (5), the meaning of each parameter is as follows:

[0126] η-equivalent damping coefficient;

[0127] F x - Aerodynamic resultant force in unsteady state;

[0128] F 0 - aerodynamic resultant force in steady state;

[0129] x- vibration direction;

[0130] ρ - air density;

[0131] c-chord length;

[0132] W-the combined speed of the downflow wind speed and the vibration wind speed in the unsteady state;

[0133] W 0 -Incoming flow velocity in steady state;

[0134] C L - lift coefficient;

[0135] C D - drag coefficient;

[0136] α-angle of attack in unsteady state;

[0137] α 0 - Angle of attack in steady state;

[0138] φ - inflow angle in unsteady state;

[0139] φ 0 - inflow angle in steady state;

[0140] θ-angle between vibration direction and reference line;

[0141] C′ L- the gradient of the lift coefficient with respect to the angle of attack;

[0142] C′ D - Gradient of the drag coefficient with respect to the angle of attack.

[0143] It can be seen from formula (5) that, in addition to the vibration direction, other parameters that affect the vibration include parameters such as the angle of attack, the incoming flow velocity, the lift and drag coefficient and its gradient. When η is negative, the aerodynamic resultant force at the cross section of the blade 30 does positive work, resulting in instability. It can be seen from the expression (5) of η that the way to increase damping and improve stability can be to increase the drag coefficient, reduce the lift coefficient, and reduce the gradient of the lift and drag coefficients. In the present invention, by installing a vibration suppression device on the blade 30, it is possible to increase the drag coefficient, reduce the lift coefficient, and reduce the lift and reduce the gradient of the drag coefficient at the same time, thereby achieving the purpose of increasing damping and improving the stability of the blade 30.

[0144] In formula (5), C D The coefficient range of the term is larger than that of the other two terms. D The most efficient way to increase the damping coefficient is D When η is large and changes little with the angle of attack, it can ensure that η is always greater than zero at any large wind speed.

[0145] The expression of formula (5) can also be used to analyze Fig.13 The stall-induced flutter model with a single vibration direction is shown in FIG. 1 . In this model, since the vibration direction of the blade 30 section is perpendicular to the incoming flow direction, θ-φ 0 =π / 2, substituting into formula (5), the part in the brackets of formula (5) can be simplified to 2(C D +C′ L ), it can be seen that when C′ L Negative and its absolute value is greater than C D When , the system is unstable. In this case, C D The coefficient of the term ranges from [2, 4], which is larger than the coefficients of the other two terms, indicating that the C D The most efficient way to increase the damping coefficient is D It is larger than the coefficients of the other two terms, so it can ensure that η is always greater than zero, thereby ensuring the stability of the system.

[0146] According to the embodiment of the present disclosure, a vibration suppression device is provided so that negative pressure is formed on the leeward side of the vibration suppression device. Due to the pressure difference on both sides, the blade 30 is subjected to an opposite pressure difference resistance in the vibration direction, thereby achieving the purpose of increasing C D The purpose is to more effectively increase the equivalent damping coefficient η and enhance the vibration suppression effect of the blade 30.

[0147] Fig.15 and Fig.16 The velocity field result of the two-dimensional CFD (Computational Fluid Dynamics) simulation of the present invention is shown as follows. The existence of the vibration suppression device exacerbates the surface flow separation between the pressure surface and the suction surface of the blade 30, making the surface velocities on both sides of the blade 30 tend to be consistent, thereby causing the pressure difference to decrease and the lift to decrease. According to formula (5), it can be determined that the damping coefficient can be increased, thereby enhancing the vibration suppression effect. At the same time, due to the obstruction of the vibration reduction device 10, the airflow velocity of the vibration reduction device 10 on the side close to the blade 30 decreases and approaches 0, thereby forming a negative pressure on the other side, generating a large pressure difference resistance. Since the flow velocity on the side close to the blade 30 of the device at different attack angles is close to 0 and relatively stable, it shows a small resistance gradient. According to formula (5), it can be determined that the damping coefficient can be increased and the vibration suppression effect can be enhanced. The present invention has the most significant effect on increasing the drag coefficient by adopting the vibration suppression device. At a large angle of attack, the drag coefficient can be increased from 0.3-0.5 to 1.5-2.0.

[0148] It is worth noting that in an actual three-dimensional scene, the equivalent stiffness distribution of the blade 30 is inversely proportional to the cube of the length from the blade root, so the most efficient way is to set the vibration reduction device 10 at the blade tip; the blade tip resistance part makes the direction of increase of the aerodynamic force opposite to the direction of speed, and the aerodynamic force does negative work, avoiding the increase and accumulation of total energy in the system, thereby achieving the effect of the damper.

[0149] According to the vibration suppression device of the present invention, the damping is increased by changing the flow on the surface of the blade 30 and by increasing the drag coefficient. Therefore, even under high wind speeds (for example, wind speeds greater than 20 m / s), vibration suppression by adding resistance can be achieved, thereby ensuring the vibration suppression effect and the structural strength of the device and solving the stability problem in the blade 30 yard and blade 30 shutdown maintenance conditions.

[0150] According to another aspect of the present invention, a wind turbine generator set having the above blade assembly is also provided. The wind turbine generator set provided in this embodiment has the blade assembly of any of the above embodiments, and thus has the beneficial effects of any of the above embodiments, which will not be described in detail here.

[0151] A fourth aspect of the present disclosure provides a method for manufacturing a vibration reduction device 10. Fig.10 FIG. 1 is a flow chart of a method for manufacturing the vibration damping device 10 according to an embodiment of the present invention. Fig.10 As shown, according to the manufacturing method of the vibration damping device 10 of an embodiment of the present invention, the vibration damping device 10 is made of a composite material, and the manufacturing method of the vibration damping device 10 includes: pultruding the composite material to form a sheet of a preset thickness; connecting a plurality of sheets and forming them into a curved structure to form the vibration damping device 10.

[0152] The manufacturing method of the vibration damping device 10 provided in the embodiment of this aspect is to make a composite material into a sheet through a pultrusion process, and to form the vibration damping device 10 by connecting and forming a plurality of sheets into a curved surface structure, which can adapt to the shape of the vibration damping device 10, improve the load-bearing performance of the vibration damping device 10, and improve the fault tolerance rate. The vibration damping device 10 is produced by using a sheet made by a pultrusion process, and the larger vibration damping device 10 can be divided into multiple pieces, and produced by splicing multiple smaller sheets. If a problem or defect occurs on a sheet during the production process, the sheet can be scrapped and replaced with a new sheet, which can improve the qualified rate of the vibration damping device 10. In other words, even if a problem is found in a sheet during the process of connecting multiple sheets into a curved surface structure, it is sufficient to replace the sheet with the problem, and it will not affect other sheets. Therefore, the fault tolerance rate can be improved by using a pultruded plate to form the rear edge auxiliary beam 140.

[0153] Hereinafter, each step of forming the vibration damping device 10 will be described in detail. In step S1, the composite material is pultruded to form a sheet of a preset thickness; a plurality of sheets are connected and formed into a curved structure to form the vibration damping device 10. As an example, the composite material includes a plastic resin material and a reinforcing fiber. The combination of the plastic resin material and the reinforcing fiber can improve the mechanical properties and load-bearing state of the sheet. The content of the reinforcing fiber and the resin material in the sheet is easy to control. The higher the fiber content, the better the mechanical properties or load-bearing state. In addition, since the fiber content in the sheet is high, the resin material content is low, and the mechanical properties are relatively excellent. The mechanical properties can be guaranteed by using less material, which is conducive to reducing the weight of the vibration damping device 10. As an example, the thermoplastic resin may include at least one of polypropylene (PP), polyethylene terephthalate (PET), nylon 6 (PA6), nylon 66 (PA66), acrylonitrile-styrene-acrylate copolymer (ASA), polyphenylene ether (PPO), polyimide (PI) and polyetheretherketone (PEEK). The above materials are all thermoplastic resins. The sheets are formed by using thermoplastic resins. The thermoplastic resins are used to conform to the shape during the heating process. The sheets are heated to conform to the shape, and then resin is poured to bond the sheets as a whole to form the vibration damping device 10. This can effectively improve the shape accuracy of the vibration damping device 10, making the vibration damping device 10 and the blade 30 more conformable. In addition, because the sheets are formed by using thermoplastic resins, the scrapped materials can be recycled and reused later, and the vibration damping device 10 made of the sheets can also be recycled and reused.

[0154] As an example, the reinforcing fiber may include at least one of glass fiber, basalt fiber, aramid fiber, carbon fiber, and synthetic fiber. All of the above materials are reinforcing materials, which not only have good stability, excellent mechanical properties and corrosion resistance, but also have the advantages of good insulation, excellent heat and sound insulation, and good wave transmission performance.

[0155] In some embodiments, optionally, Fig.11 As shown, each sheet is a straight plate, and the structures of the multiple sheets are the same. The straight plate is easier to process and produce, and the multiple straight plates can also be formed into a curved body that follows the mold through subsequent heating, ensuring the shape accuracy of the vibration reduction device 10.

[0156] In some embodiments, the thickness of the sheet is 1 mm to 2 mm. Within this range, the thickness of the sheet is neither too thin to affect the structural strength nor too thick to make it difficult to achieve the step of softening the sheet into a curved body that follows the mold after heating, which is conducive to the processing and production of the vibration reduction device 10.

[0157] In some embodiments, the length of the sheet is 8m to 15m. Generally speaking, the sheet is not spliced ​​in the length direction of the vibration reduction device 10, which can simplify the processing process of the vibration reduction device 10 and facilitate molding. Therefore, the length of the sheet is roughly the same as the length of the vibration reduction device 10. Within this range, the vibration reduction device 10 has a sufficient length to effectively suppress vibration, and will not interfere with other components on the blade 30 due to the excessive width of the vibration reduction device 10 in the span direction of the blade 30.

[0158] Further, in step S2, the step of connecting and molding a plurality of sheets into a curved structure to form the vibration damping device 10 includes: laying a plurality of sheets in a mold for forming the vibration damping device 10, such as Fig.12 As shown, the inner surface of the mold is arched, and multiple sheets are spliced ​​and laid on the inner surface of the mold along the circumferential direction of the mold, and the multiple sheets are spliced ​​to form a curved surface. As an example, multiple sheets can be spliced ​​and laid on the inner surface of the mold along the circumferential direction of the mold, and the shape after splicing is generally the same as the mold, generally in the shape of a curved surface, such as Fig.12 The number of sheets in the mold is not specifically limited until the width requirement is met.

[0159] Further, in step S3, the mold is heated to a temperature higher than the softening temperature of the sheet material to soften the sheet material and form a curved body that conforms to the mold. As an example, the mold can be heated to above 130°C (for example, above 150°C) and then kept warm until the sheet material softens and conforms to the mold. The heating temperature of the mold can be changed according to the specific material of the thermoplastic resin, and the present invention does not impose any specific restrictions on this, as long as the sheet material can be softened. In addition, the insulation time is not specifically limited, as long as the sheet material can be softened.

[0160] Further, in step S4, resin is poured into the curved body and cured to form the vibration reduction device 10. For example, the resin can be poured into the conformable laminate by a vacuum-assisted pouring system. Specifically, after forming the curved body conformable to the mold, the mold can be cooled to, for example, room temperature, and then the vacuum pouring system can be arranged. Vacuum auxiliary materials can be laid on the curved body. For example, the vacuum auxiliary materials can include a demoulding cloth, an isolation film, a guide net, a glue injection tube, an exhaust tube, and a vacuum bag film.

[0161] A vacuum-assisted infusion system may be used to infuse resin into the curved body under vacuum conditions. As an example, the resin infused into the curved body may be a thermosetting resin or a thermoplastic resin, and the present invention does not impose any specific restrictions on this. For example, the infusion resin may be an epoxy resin. When the infusion resin is an epoxy resin, the temperature may be maintained at 40°C-50°C for 5-7 hours, and then the temperature may be increased to 70°C-80°C for 5-7 hours.

[0162] Although the embodiments of the present application have been described in detail above, those skilled in the art may make various modifications and variations to the embodiments of the present disclosure without departing from the spirit and scope of the present disclosure. It should be understood that, in the view of those skilled in the art, these modifications and variations will still fall within the spirit and scope of the embodiments of the present disclosure defined by the claims.

Claims

1. A vibration reduction device (10) for installation on a blade (30) of a wind turbine generator set, It is characterized in that The vibration reduction device (10) is made of a hard material and is formed into a curved surface structure. It is capable of surrounding a portion of the outer circumference of the blade (30) and is separated from the blade (30) by a predetermined gap to form a wind-absorbing cavity (110) on one side of the blade (30), thereby increasing the damping of the blade (30) and suppressing the vibration of the blade (30).

2. The vibration damping device (10) according to claim 1, It is characterized in that A plurality of outwardly extending corners are formed at the edge of the curved structure, and the vibration reduction device (10) can be connected to the blade (30) through the corners. The corners can be supported on the surface of the blade (30), and an air inlet (350) is formed between two adjacent corners and the blade (30) to allow air flow to enter the ventilation cavity (110).

3. The vibration damping device (10) according to claim 2, It is characterized in that In the length direction of the blade (30), the vibration reduction device (10) is bent to form a plurality of continuous curved surface structures and has a plurality of corners arranged at intervals, and an air inlet (350) is formed between two adjacent corners and the blade (30).

4. The vibration damping device (10) according to claim 1, It is characterized in that An opening is formed at the edge of the curved surface structure, and the opening can be covered on the blade (30). There is a gap between the edge of the curved surface structure and the blade (30), and the gap forms an air inlet (350).

5. The vibration damping device (10) according to any one of claims 1 to 4, It is characterized in that The vibration reduction device (10) can be respectively wrapped around the pressure side (320) and the suction side (310) of the blade (30), wherein each curved surface structure located on the pressure side (320) of the blade (30) includes two corners, and each curved surface structure located on the suction side (310) of the blade (30) includes two corners.

6. The vibration damping device (10) according to any one of claims 1 to 4, It is characterized in that The vibration reduction device (10) is made of any one of glass fiber reinforced plastics, gypsum, and hard foam; and / or The vibration damping device (10) is made of any one of PP, PET, PA6, PA66, ASA, PPO, PI, and PEEK.

7. The vibration damping device (10) according to claim 1, It is characterized in that The vibration reduction device (10) is provided with a plurality of ventilation holes for adjusting the wind resistance of the vibration reduction device (10).

8. A blade assembly, It is characterized in that include: A blade (30) and a vibration damping device (10) according to any one of claims 1 to 7, The vibration reduction device (10) is connected to the outer surface of the blade (30).

9. The blade assembly according to claim 8, It is characterized in that The blade assembly also includes: A connecting piece (20) connects the vibration reduction device (10) to the blade (30) and positions the wind-absorbing cavity (110) on the suction side (310) of the blade (30) so as to reduce the velocity of the airflow passing through the suction side (310) of the blade (30).

10. The blade assembly according to claim 9, It is characterized in that The wind-entraining cavity (110) also extends from the suction side (310) of the blade (30) to the pressure side (320) of the blade (30), so that the flow velocity of the airflow flowing through the pressure side (320) of the blade (30) is reduced, and the pressure difference between the pressure side (320) and the suction side (310) is reduced.

11. The blade assembly according to any one of claims 8 to 10, It is characterized in that The blade assembly also includes: A buffer pad (50) is arranged between the vibration damping device (10) and the blade (30) to separate the vibration damping device (10) from the blade (30).

12. The blade assembly according to claim 11, It is characterized in that There are a plurality of the buffer pads (50), and the plurality of the buffer pads (50) are distributed at intervals along the span direction of the blade (30), with a spacing between two adjacent buffer pads (50).

13. The blade assembly according to claim 9, It is characterized in that The connecting member (20) comprises a binding rope, which is fixedly connected to the vibration damping device (10) and can fix the vibration damping device (10) on the blade (30), and enables the vibration damping device (10) to be surrounded on the surface of the blade (30) to form a bag shape having an air inlet (350), so that external airflow can enter between the vibration damping device (10) and the blade (30) through the air inlet (350).

14. The blade assembly according to claim 13, It is characterized in that The connecting member (20) further comprises a tightener connected to the tying rope, wherein the tightener can adjust the tightness of the tying rope; The two ends of the vibration damping device (10) are respectively covered on the pressure side (320) and the suction side (310) of the blade (30), and two corners of the vibration damping device (10) are located on the pressure side (320) of the blade (30), and the other two corners are located on the suction side (310) of the blade (30). On each side of the pressure side (320) and the suction side (310), the binding rope is connected to the two corners of the vibration damping device (10) and is wrapped around the circumference of the blade (30) to prevent the vibration damping device (10) from moving on the blade (30).

15. A wind turbine generator set, It is characterized in that The wind turbine generator set comprises the blade assembly according to any one of claims 8 to 14.

16. A method for manufacturing a vibration reduction device (10), It is characterized in that The vibration damping device (10) is made of a composite material, and the manufacturing method of the vibration damping device (10) comprises: pultruding the composite material to form the composite material into a sheet of a predetermined thickness; A plurality of the sheets are connected and formed into a curved structure to form the vibration damping device (10).

17. A method for manufacturing a vibration damping device (10) according to claim 16, It is characterized in that The step of connecting and shaping a plurality of the sheets into a curved structure to form the vibration damping device (10) comprises: Laying a plurality of the sheets in a mold for forming the vibration damping device (10), the inner surface of the mold being arched, splicing the plurality of sheets along the circumferential direction of the mold and laying them on the inner surface of the mold, so that the plurality of sheets are spliced ​​to form a curved surface; The mold is heated to a temperature higher than the softening temperature of the sheet material, so that the sheet material softens and forms a curved body conforming to the mold; Resin is poured into the curved body and cured to form the vibration damping device (10).

18. A method for manufacturing a vibration damping device (10) according to claim 17, It is characterized in that The manufacturing method of the vibration reduction device (10) further comprises: After forming a curved body conforming to the mold and before infusing resin into the curved body and solidifying the resin, the method further includes arranging a vacuum infusion system after cooling the mold.

19. A method for manufacturing a vibration damping device (10) according to claim 16, It is characterized in that The composite material comprises a plastic material and reinforcing fibers.

20. A method for manufacturing a vibration damping device (10) according to claim 19, It is characterized in that The plastic material includes any one of PP, PET, PA6, PA66, ASA, PPO, PI, and PEEK; The reinforcing fiber includes any one of glass fiber, basalt fiber, aramid fiber, carbon fiber and synthetic fiber.

21. A method for manufacturing a vibration damping device (10) according to claim 16, It is characterized in that The thickness of the sheet is 1 mm to 2 mm; and / or The length of the sheet is 8m to 15m.

22. A method for manufacturing a vibration damping device (10) according to claim 17, It is characterized in that The resin poured into the curved body is a thermoplastic resin or a thermosetting resin; and / or Each of the sheets is a straight plate, and the structures of the multiple sheets are the same.

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