Damper, blade for wind turbine, and wind turbine

Abstract

The present application provides a damper, a blade for a wind turbine generator set, and a wind turbine generator set, wherein the damper includes: a damper housing, forming a receiving chamber for receiving damping fluid; a plurality of curved partitions, extending along the width direction of the receiving chamber, and arranged at intervals in the length direction of the receiving chamber, dividing the receiving chamber into a plurality of sub-receiving chambers; a plurality of rolling balls, arranged in each sub-receiving chamber. The damper provided in the embodiment of the present application adjusts the damping value of the blade by arranging rolling balls and damping fluid to form a damper. When the blade experiences shutdown flutter, the damper fully functions to suppress the vibration intensity of the blade by increasing the damping.

Description

Technical Field

[0001] The present application relates to the technical field of wind power generation, and in particular to a damper and a blade using the damper, and a wind power generator set using the damper or the blade. Background Art

[0002] At present, as the size of blades continues to increase, the weight and load continue to increase, the requirements for the structural strength and fatigue performance of blades are also getting higher and higher. In addition, when large wind turbines are in shutdown conditions and there is side wind in the wind farm, blade flutter problems will occur. Long-term vibration will seriously threaten the safety of the entire unit. The blades are made of composite materials with a damping ratio of about 0.2%. The damping value is too small to suppress severe vibrations.

[0003] The blades are always rotating during operation. If the dampers in the building are directly installed into the blades, they will always work with the rotation of the wind wheel. Under the action of long-term fatigue loads, the dampers and surrounding structures are prone to damage, which will affect the safety of the blades. Therefore, it is particularly important to provide a damper suitable for wind turbines. Summary of the invention

[0004] Therefore, the present application increases the damping value of the blade by installing a damper inside the blade, reduces the flutter of the blade when the wind turbine is in a shutdown state, reduces the risk of vibration damage to the blade, improves the safety and reliability of the blade, and extends the service life of the blade.

[0005] One aspect of the present application is to provide a damper, comprising: a damper housing, forming a receiving chamber for receiving damping fluid; a plurality of curved partitions, extending along the width direction of the receiving chamber and arranged at intervals in the length direction of the receiving chamber, dividing the receiving chamber into a plurality of sub-receiving chambers; and a plurality of rolling balls, respectively arranged in each sub-receiving chamber.

[0006] The damper provided in the embodiment of the present application adjusts the damping value of the blade by arranging a rolling ball and a damping fluid to form a damper. When the blade stops fluttering, the damper fully functions, and the damping is increased by the friction of the damping ball in the damping fluid to suppress the vibration intensity of the blade, reduce the risk of vibration damage to the blade, improve the safety and reliability of the blade, and extend the service life of the blade.

[0007] In some embodiments, the curved partition plate is provided with through holes so that the sub-accommodation chambers are interconnected. By providing the through holes, the damping fluid in two adjacent sub-accommodation chambers can flow freely.

[0008] In some embodiments, the material of the ball includes: magnetic material, an electromagnet assembly is arranged on one side of the damper housing in the width direction, and the electromagnet assembly includes: an electromagnetic relay, which is arranged on an outer side surface of the damper housing in the width direction. The damper provided in the embodiment of the present application uses an electromagnetic relay to control the movement of the ball. When the blade flutters and the electromagnetic relay is not working, the ball can follow the movement of the blade and move frictionally in the damper to increase the damping. When the blade rotates normally or is stationary, when the electromagnetic relay is working, the magnetic field generated by it adsorbs the ball to the inner side surface of the damper housing, locking the ball so that it no longer moves. At the same time, it can also prevent the ball from generating excess heat due to movement, which affects the damper and the surrounding bonding structure.

[0009] In some embodiments, the electromagnet assembly further comprises: a steel baffle plate, which is arranged on the outer side of the damper housing along the length direction of the damper housing, wherein the electromagnetic relay is arranged on the steel baffle plate. Considering that the range of action of the electromagnet assembly is relatively limited and may not cover the area of ​​the damper housing, the steel baffle plate with a larger area can be magnetized by the electromagnet assembly first, and then the steel baffle plate can be used to attract the rolling ball. The steel baffle plate is equivalent to a bridge for transmitting the magnetic field.

[0010] In some embodiments, the damper further includes a controller and a vibration sensor; when the vibration sensed by the vibration sensor is lower than a predetermined value, the controller controls the electromagnetic relay to operate, magnetizes the steel baffle, and thereby adsorbs the rolling ball to the inner wall surface of the damper housing near the steel baffle, and when the vibration is equal to or greater than the predetermined value, the electromagnetic relay stops operating to release the rolling ball. When the vibration is less than the predetermined value, the electromagnetic relay operates to attract the rolling ball and locks the rolling ball on the inner wall surface of the damper housing.

[0011] In some embodiments, the damper further comprises a heat sink disposed outside the damper housing. The heat sink is provided at least for dissipating heat from the damper, reducing deformation or shedding of the damper and its surrounding adhesive structures due to heat, thereby avoiding impact on the safety of the blade.

[0012] In some embodiments, the radiator is an air-cooled radiator, and the damper further includes a temperature sensor and a fan disposed on one side of the radiator. The temperature sensor is disposed on the outer wall of the damper housing or in the accommodating cavity. When the temperature sensed by the temperature sensor exceeds a predetermined value, the controller controls the fan to start to dissipate heat from the damper. When the temperature sensed by the temperature sensor does not exceed a predetermined value, the controller controls the fan to shut down to save energy. In the embodiment of the present application, the predetermined temperature value is set to control the radiator to dissipate heat from the damper and its surroundings to ensure safe and reliable bonding of the damper and its surrounding structures.

[0013] In some embodiments, the damper housing is approximately a cube, the heat sink is arranged above the upper outer surface of the damper housing in the thickness direction, and the damper further comprises a honeycomb core panel arranged on the lower outer surface of the damper housing in the thickness direction. The honeycomb core panel is arranged at the contact position between the damper and the mounting cavity in the blade, so as to reduce the secondary vibration of the blade caused by the vibration of the damper.

[0014] In some embodiments, the damper housing is further provided with an infusion port for infusing the damping fluid into the accommodating chamber, the diameter of the ball is 20%-30% of the distance between two adjacent curved partitions, the diameter of the ball is larger than the diameter of the through hole, the magnetic material includes any one of the following: iron, nickel, cobalt, and the material of the ball also includes: rubber, which is coated on the outer surface of the ball. The present application sets a magnetic material as the inner core, which has a strong impact force, so rubber is set on the outer surface of the ball to reduce the impact of the inner core on the wall of the damper housing and the wall of the curved partition, avoiding damage caused by direct impact of the inner core. The diameter of the ball is set to be larger than the diameter of the through hole to avoid multiple balls from moving in each sub-accommodating chamber and causing them to gather together. When the diameter of the ball is too small, the damping provided is insufficient; when the diameter of the ball is too large, the movement of multiple balls in each sub-accommodation chamber is restricted. Therefore, when the diameter of the ball is 20%-30% of the distance between two adjacent curved partitions, it can ensure that multiple balls can move freely in each sub-accommodation chamber when in a free state, and can also provide sufficient damping.

[0015] In some embodiments, the damper further includes a damping liquid in the accommodating chamber, and the damping liquid accounts for 80%-90% of the capacity of the accommodating chamber. This is to avoid the influence of the damping liquid proportion caused by the damping liquid expanding and contracting due to the temperature difference in seasons. At the same time, the damping liquid is set to account for 80%-90% of the capacity of the accommodating chamber. When the blade rotates normally, due to the limited flow space range of the damping liquid, smaller damping can be generated to suppress the swinging deformation.

[0016] In some embodiments, at standard atmospheric pressure 25 o C, the viscosity of the damping fluid is in the range of 300-500 centipoise. When the ball moves, it contacts and rubs against the damping fluid, generating a large damping. The viscosity of the damping fluid directly affects the effect of the damper. If the viscosity is too high, the movement of the ball is hindered and it cannot function well. If the viscosity is too low, the damping is insufficient.

[0017] According to another aspect of the present application, there is provided a blade for a wind turbine generator set, the blade comprising a blade shell and the damper described above, wherein the damper is arranged inside the blade shell.

[0018] The damper of the embodiment of the present application is arranged on the inner side of the blade shell, which can effectively suppress the vibration generated by the blade flutter without affecting the power generation efficiency, and has a simple structure.

[0019] In some embodiments, the length direction of the damper is arranged along the swing direction of the blade, and the width direction of the damper is arranged along the swing direction of the blade. The width direction of the damper is arranged along the swing direction of the blade, and the curved partition for guiding the movement of the rolling ball is also arranged along the swing direction of the blade. Therefore, when the blade flutters, setting the guiding direction of the rolling ball to be the same as the flutter direction of the blade can have a better suppression effect on the flutter.

[0020] The damper of the present application can be installed at the leading edge, trailing edge or between two webs of the blade. Under the premise of ensuring the safe operation of the blade, the damper can improve the vibration suppression effect, especially when the blade flutters, the vibration suppression effect is more obvious.

[0021] In some embodiments, the damper is installed on the inner side of the suction surface shell of the blade, near the trailing edge of the blade tip. Under the premise of ensuring the safe operation of the blade, it is set as far as possible at a position that is conducive to suppressing the flutter of the blade, which can reduce the impact of the flutter on the safety of the blade to a greater extent.

[0022] In some embodiments, the total weight of the damper is 4%-7% of the original weight of the blade. If the damper is too heavy, the blade will be overloaded during operation, which may pose a safety hazard. If the damper is too light, the damping effect will be poor, and the vibration suppression effect will not be obvious when the blade flutters. Therefore, setting the total weight of the damper to 4%-7% of the original weight of the blade can ensure safety performance and provide sufficient damping.

[0023] According to another aspect of the present application, a wind turbine generator set is provided, wherein the wind turbine generator set comprises the damper described above, and / or the blade for the wind turbine generator set described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other objects and features of the present application will become more apparent through the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0025] Figure 1 is a structural schematic diagram of a damper provided in an embodiment of the present application;

[0026] Figure 2 It is a partial perspective structural schematic diagram of a damper installed on a blade provided by an embodiment of the present application;

[0027] Figure 3 The embodiment of this application provides Figure 2 Schematic diagram of the cross-section structure along the AA plane;

[0028] Figure 4 is a perspective structural diagram of a blade provided in an embodiment of the present application;

[0029] Figure 5 is a schematic diagram of the installation position of the damper in the blade provided in the embodiment of the present application;

[0030] Figure 6 The embodiment of this application provides Figure 5 Schematic diagram of the structure in which the blades are flipped 180°.

[0031] Description of Figure Numbers:

[0032] 10. Damper housing; 11. Accommodating chamber; 12. Filling port;

[0033] 20. Curved partitions;

[0034] 30. Rolling ball;

[0035] 40. Electromagnetic assembly; 41. Electromagnetic relay; 42. Steel baffle;

[0036] 60. Vibration sensor; 70. Temperature sensor; 80. Fan; 90. Honeycomb core panel;

[0037] 100, blade; 200, damper; F1, flapping direction; F2, swing direction; B1, suction surface; B2, pressure surface. DETAILED DESCRIPTION

[0038] Now, embodiments according to the present application will be described in detail with reference to the accompanying drawings, examples of which are shown in the accompanying drawings, wherein like reference numerals refer to like components throughout.

[0039] An embodiment of the present application provides a damper for suppressing vibration, such as Figure 1The damper includes: a damper housing 10, a plurality of curved partitions 20 and a plurality of rolling balls 30, wherein the damper housing 10 forms a receiving chamber 11 for receiving damping fluid; the plurality of curved partitions 20 extend along the width direction of the receiving chamber 11 and are arranged at intervals in the length direction of the receiving chamber 11 to divide the receiving chamber 11 into a plurality of sub-receiving chambers, and a through hole is opened on the curved partition 20 for connecting the sub-receiving chambers to each other, and the plurality of rolling balls 30 are respectively arranged in the sub-receiving chambers.

[0040] In an embodiment of the present application, the damper can be set in structures such as buildings, bridges, cooling towers, etc. to suppress vibrations, and can also be set on blades, towers, nacelles and other components of a wind turbine. Below, the present application will be described using the blades of a wind turbine as an example.

[0041] The shape of the damper housing 10 of the present application is specifically set according to the shape of the component or structure to be applied thereto. When used to be set on the blades of a wind turbine generator set, the shape of the damper can be specifically set according to the installation position on the blades.

[0042] like Figures 2 to 3 As shown, the length direction of the damper is arranged along the swing direction F1 of the blade 100, and the width direction of the damper is arranged along the swing direction F2 of the blade 100. Among them, the swing direction F1 is equivalent to the length setting direction of the blade, exemplarily: the direction from the blade root to the blade tip or the direction from the blade tip to the blade root. The swing direction F2 is perpendicular to the swing direction F1, that is, it is equivalent to the direction from the leading edge to the trailing edge. After the damper and the blade are installed, each curved baffle 20 is arranged on the blade along the swing direction F2 (that is, the leading edge points to the trailing edge). By arranging the curved baffle 20 along the swing direction F2, the present application can, on the one hand, guide the ball 30 to move along the swing direction F2. Since the movement direction of the ball 30 is the same as the flutter direction of the blade 100, the reciprocating motion of the ball 30 in the damping fluid can effectively suppress the flutter of the blade 100. On the other hand, the curved partition 20 can also effectively separate the balls 30 to prevent the balls 30 from piling up and to prevent multiple balls 30 from simultaneously hitting a certain position of the damper housing 10, thereby causing damage to the damper. The curved partition 20 can also be provided so that when the blade 100 flutters, the balls 30 can reduce the impact force on the inner wall of the damper housing 10 by hitting the wall of the curved partition 20. If there is no curved partition 20, the balls 30 will directly impact the wall of the damper, threatening its structural safety. A through hole is provided on the curved partition 20 to connect the various sub-accommodation chambers to each other so that the damping fluid in two adjacent sub-accommodation chambers can flow freely. The diameter of the ball 30 is larger than the diameter of the through hole, so that the ball 30 will not pass through the through hole and gather in a certain sub-accommodation chamber.

[0043] The damper provided in the embodiment of the present application adjusts the damping value of the blade 100 by arranging the rolling ball 30 and the damping fluid to form a damper. When the blade 100 experiences shutdown flutter, the damper fully functions to suppress the vibration intensity of the blade 100 by increasing the damping.

[0044] In order to ensure that the rolling ball 30 is in full contact with the damping fluid during movement and to avoid clogging with the partition, the diameter of the rolling ball 30 is 20%-30% of the distance between two adjacent curved partitions 20. For example, the distance between two adjacent curved partitions 20 is 100mm-133mm, and the diameter of the damping ball is set to 20-30mm to ensure that the rolling ball 30 can move freely in the sub-accommodation cavity formed by the two adjacent curved partitions 20. The rolling ball 30 is an iron core sphere covered with rubber to avoid damage to the damper wall caused by long-term impact of the damping ball. Here, the inner wall material of the damper housing 10 can be made of glass fiber composite material.

[0045] In the embodiment of the present application, the damping fluid is a viscous damping fluid. For example, the damping fluid that can be used includes methyl silicone oil and modified silicone oil. In the embodiment of the present application, the selection of the viscous damping fluid needs to consider the following factors:

[0046] First, viscosity factor: The viscosity of the damping fluid is selected based on the damping required during vibration. The viscosity of the damping fluid directly affects the effect of the damper. If the viscosity is too high, the movement of the ball 30 is hindered and it cannot function well. If the viscosity is too low, the damping produced is insufficient.

[0047] Second, temperature difference changes: Since wind turbines operate outdoors, the annual average temperature in the installation area changes dramatically. The thermal expansion and contraction characteristics of the damping fluid need to be fully considered. The damping fluid must account for 80%-90% of the damper capacity and the total mass of the damper must be 4%-7% of the original weight of the blade to ensure the safety of the blade during operation.

[0048] Therefore, in some embodiments, the damping fluid occupies 80%-90% of the capacity of the accommodating chamber 11, and at a standard atmospheric pressure of 25 o C, the viscosity of the damping fluid ranges from 300 to 500 centipoise.

[0049] In the damper provided in the embodiment of the present application, when the blade 100 vibrates, the ball 30 in the damper will repeatedly move back and forth along the surface of the curved partition 20. During the movement, the ball 30 and the damping fluid are in contact and friction, generating greater damping, thereby reducing the vibration intensity of the blade 100.

[0050] In addition, the damper housing 10 may also be provided with a filling port 12 connected to the accommodating chamber 11. In order to facilitate the transportation of the damper and reduce the transportation cost, the damping liquid may not be filled in the transportation process. When in use, the damping liquid of the corresponding viscosity is poured into the accommodating chamber 11. In the embodiment of the present application, in order to prevent the damping liquid from leaking at the filling port 12, a sealing plug, a sealing gasket and an outer sealing layer are used to complete the sealing. First, a sealing gasket is used and a sealing plug is filled, and an outer sealant or resin (such as epoxy resin) is applied to the outside of the sealing plug. After it is completely dried, the next layer is applied to ensure the long-term sealing of the filling port 12. After working for a long time, the damping liquid needs to be replaced or added. The sealing position is first heated, and the outer sealant layer is torn off, and then the sealing plug is pulled out, and the damping liquid is replaced or added using a hose. After completion, the sealing state is restored again. The diameter of the filling port 12 is 20-50mm, and the size of the outer sealant layer must be at least three times larger than the diameter of the filling port 12 to ensure the reliability of the seal. In order to ensure that the damper can produce greater damping, a damping liquid of appropriate viscosity is added to the damping pool along the filling port 12 to ensure that when the blade is in a flutter state, sufficient damping can be obtained to suppress vibration in a shorter period of time and avoid damage to the blade caused by long-term vibration. Of course, the present application may not be provided with a filling port 12. When the filling port 12 is not provided, the damping liquid can be directly filled into the accommodating chamber 11 and then sealed. However, in this case, when the damping liquid needs to be replaced, it is not conducive to the operation of replacing the damping liquid. In an embodiment of the present application, a through hole is provided at the bottom of the blade corresponding to the filling port 12. When the damping liquid needs to be replaced, the damping liquid is replaced through the through hole.

[0051] In some embodiments, uneven surfaces are provided on the curved baffle 20 and vary evenly, or the surface of the curved baffle 20 is roughened to increase the surface area of ​​the curved baffle 20, thereby allowing the damping fluid to contact the curved baffle 20 for a longer time when flowing, thereby increasing the friction between the damping fluid and the curved baffle 20 when flowing, thereby increasing the damping.

[0052] In order to increase the damping by the friction of the ball 30 in the damping fluid when the blade 100 flutters, and to keep the damping as small as possible to ensure the safety of the blade when the blade rotates, so as to avoid damage to the blade caused by long-term heat, based on this, the present application is arranged to allow the ball 30 to move freely when the blade 100 flutters, and to limit the ball 30 when the blade 100 rotates or stops. The restraint state of the ball 30 can be controlled by mechanical control, for example: a limit baffle, and the restraint state of the ball 30 can also be controlled by magnetic field induction.

[0053] Therefore, in some embodiments, the material of the ball 30 includes: magnetic material, an electromagnet assembly 40 is arranged on one side of the damper housing 10 in the width direction, and the electromagnet assembly 40 includes: an electromagnetic relay 41, which is arranged on any outer side surface of the damper housing 10 in the width direction along the damper housing 10.

[0054] In the embodiment of the present application, the electromagnet assembly 40 can directly act on the magnetic material in the ball 30 to control the restraint state of the ball 30. An electromagnetic relay is arranged on the outer side of the damper housing 10 to control the restraint state of the ball 30. When the electromagnet assembly 40 is not working, the ball 30 can move freely following the movement of the blade 100. When the electromagnet assembly 40 is working, it generates a magnetic field to adsorb the ball 30 to the inner side of the damper housing 10 to lock the ball 30.

[0055] In the embodiment of the present application, the electromagnetic force between the ball 30 and the electromagnet assembly 40 needs to be set to be greater than the maximum vibration force received by the ball 30. Here, the corresponding magnetic field strength needs to be set to ensure that the ball 30 will not separate from the inner wall surface of the damper housing 10 when the blade 100 rotates normally. In the embodiment of the present application, the magnetic field strength is calculated by the following formula:

[0056] When the relay is working, make sure that: .in, F m is the magnetic field force generated by the relay on the ball, F v is the maximum vibration force on the ball when the blade flutters, .in, m is the mass of the rolling ball (unit kg ), a Set the threshold for blade flutter (unit m / s -2 ).

[0057] The magnetic field force that the relay needs to generate is obtained through the above, and the corresponding magnetic field strength B is obtained according to the following formula as the magnetic induction intensity (unit: wb) that needs to be generated.

[0058]

[0059] Where μ0 is the vacuum magnetic permeability, which is a constant of 4π*10 -7 wb, S is the cross-sectional area (unit: m 2 ).

[0060] In the embodiment of the present application, the power source of the electromagnet assembly 40 is the power source at the hub center of the wind turbine blade (conventional wind turbines are equipped with a power source at the hub center to provide power to the pitch mechanism of the blade 100), and the electromagnet assembly 40 is connected to the power source through a power cord.

[0061] Taking into account that the range of action of the electromagnet assembly 40 is relatively limited, in order to ensure that the magnetic field generated by the electromagnet assembly 40 has a sufficient coverage range, in some embodiments, the electromagnet assembly 40 also includes: a steel baffle 42, which is arranged on the outer side of the damper housing 10 along the length direction of the damper housing 10, wherein the electromagnetic relay 41 is arranged on the steel baffle 42, so that the magnetic field will not fail to cover the area of ​​the damper housing 10 (the uncovered area cannot attract the ball 30). The embodiment of the present application expands the area of ​​the magnetic field generated by the electromagnetic relay 41 by setting the steel baffle 42, and then attracts the ball 30 through the steel baffle 42. Here, the steel baffle 42 is equivalent to a bridge for transmitting the magnetic field.

[0062] Due to the difference in mass and stiffness distribution of the blade 100, there is a certain difference in acceleration and frequency when the blade 100 stops fluttering (compared with when the blade rotates normally or is stationary). In order to make the control more convenient and simple, in some embodiments, the damper also includes a controller and a vibration sensor 60; when the vibration sensed by the vibration sensor 60 is lower than a predetermined value, the controller controls the electromagnetic relay 41 to work, so that the steel baffle 42 is magnetized, so that the ball 30 is adsorbed to the inner wall surface of the damper housing 10 close to the steel baffle 42. When the vibration is equal to or greater than the predetermined value, the electromagnetic relay 41 stops working to release the ball 30. When the blade 100 is in a normal rotation or stationary state, the ball 30 is locked so that it no longer moves, so as to achieve the purpose of not increasing damping and avoid the damper 200 heating up and affecting the safety of the blade 100.

[0063] In the embodiment of the present application, it is necessary to pre-design corresponding vibration discrimination conditions according to the difference in mass and stiffness distribution of the blade 100. By setting two judgment conditions based on vibration acceleration and vibration frequency, it is sufficient to distinguish the flutter state of the blade from other states. For example, for the blade type of the present application, when the length is 60m, when the vibration acceleration of the blade 100 is greater than 1.2m / s 2, and when the vibration frequency f is near the first-order swing array frequency (within the range of ±6% Hz), the blade 100 is set to be in a flutter state. Among them, the swing frequency can be obtained in the following way: due to the difference in mass and stiffness distribution of the blade 100, the natural frequency and corresponding vibration mode of each blade are different. The natural frequency here belongs to the inherent properties of each blade, such as: first-order natural frequency, second-order natural frequency, and third-order natural frequency. When performing engineering calculations, the multi-order natural frequencies and corresponding vibration modes of the blade can be obtained. The type of natural frequency is determined according to the array, such as: flapping vibration mode, torsional vibration mode, and swing vibration mode. Observe the vibration mode corresponding to the natural frequency of the blade in sequence. When there is deformation in the swing direction for the first time, it is recorded as the first-order swing frequency of the blade. When there is deformation in the swing direction for the second time, it is recorded as the second-order swing frequency of the blade. By analogy, the Nth-order swing frequency is obtained.

[0064] In some embodiments, a vibration sensor 60 is provided to obtain vibration acceleration and vibration frequency. The controller determines the state of the blade based on the obtained vibration acceleration and vibration frequency, thereby controlling the opening or closing of the electromagnetic relay 41, and further controlling the locking or free movement of the ball 30. The damper provided in the embodiment of the present application is provided with a magnetic material such as iron, nickel, cobalt, etc. as the inner core of the ball 30, and the outer surface of the ball 30 is coated with rubber as the outer surface of the ball 30. In the case of blade flutter, the electromagnet assembly 40 does not work, that is, the electromagnet assembly 40 does not generate a magnetic field. The ball 30 is free at this time and can move in the damping fluid to increase damping. When the blade is rotating or stopped, the electromagnet assembly 40 works, that is, the electromagnet assembly 40 generates a magnetic field to act on the ball 30. At this time, the ball 30 is not moving, and the damping fluid in the accommodating chamber 11, in theory, the liquid sloshing and the friction with the wall surface will produce damping, which has a suppressing effect on vibration. However, since the volume of the damping liquid of the present application accounts for 80%-90% of the volume of the accommodating chamber 11, the space for the liquid to flow in the accommodating chamber 22 is relatively small, and the damping generated is also relatively small. On the other hand, when the blade 100 is in a normal rotation state, if the damping is simply increased, it can have a suppressive effect on the vibration, but blindly increasing the damping will also increase the corresponding heat generation, which will directly affect the safety of the blade operation and is too risky. Based on this, by setting the electromagnet assembly 40 to act on the ball 30, the damping is increased when the blade flutters to suppress the damage to the blade caused by the flutter, and when the blade is in operation, the damping is increased as little as possible (to avoid temperature rise), so that the operation of the blade is safer and more reliable. Compared with traditional dampers, the advantage of the present invention is that the damping can be adjusted according to the state of the blade 100.

[0065] During the operation of the wind turbine, the blades 100 are always rotating. During this process, the blades 100 are greatly deformed by swinging and slightly deformed by swinging. At this time, the damping fluid in the damper flows slowly. Although the damper has a large surface area and good heat dissipation capacity, the long-term continuous operation of the unit and the shutdown flutter will still cause the damper to heat up. In order to prevent the damping fluid formed by the viscous liquid and the damper housing 10 from heating up and expanding after the blades 100 vibrate for a long time, threatening the reliability of the bonding between the damper and the surroundings, in some embodiments, the damper also includes a radiator disposed on the outside of the damper housing 10. In the embodiment of the present application, a radiator is provided to dissipate heat from the damper housing 10 to prevent the safety of the blades from being affected by the temperature increase.

[0066] In some embodiments, the radiator is an air-cooled radiator, and the damper also includes a temperature sensor 70 and a fan 80 arranged on one side of the radiator. The temperature sensor 70 is arranged on the outer wall of the damper housing 10 or in the accommodating cavity 11. When the temperature sensed by the temperature sensor 70 exceeds a predetermined value, the controller controls the fan 80 to start, and the fan 80 delivers air to cool the damper and its related components. When the temperature sensed by the temperature sensor 70 does not exceed the predetermined value, the controller controls the fan 80 to turn off to save energy.

[0067] In the embodiment of the present application, the predetermined value can be set to 55°C. When the blade is in the initial state, the electromagnetic relay 41 works to magnetize the steel baffle 42, so that the ball 30 in the damper is fixed on the inner wall of the damper housing 10 near the steel baffle 42. At this time, the ball 30 will not move with the deformation of the blade 100. When the vibration sensor 60 detects that the blade 100 is vibrating, the electromagnetic relay 41 stops working to release the ball 30, so that the ball 30 will move in the accommodating cavity 11 with the vibration of the blade 100, contact and rub with the damping fluid and the curved partition 20, and rapidly increase the damping, thereby weakening the amplitude of the blade 100 flutter, but at the same time, the damper gradually heats up due to the absorption of energy. When the temperature sensor 70 detects that the temperature of the wall of the damper housing 10 exceeds the temperature threshold (about 55°C), the radiator is triggered to start working.

[0068] In the embodiment of the present application, the control of the radiator and the electromagnetic relay of the damper can be achieved by the following methods:

[0069] The control of the entire damper involves two actuators, the electromagnetic relay 41 and the radiator. The vibration sensor 60 controls the two according to the vibration judgment basis in combination with the temperature sensor 70 according to the temperature judgment basis. The detailed control logic diagram is as follows.

[0070] S100, determining whether the blade is in normal rotation or stationary state, and whether the blade is not vibrating;

[0071] In the embodiment of the present application, if the blade is in normal rotation or stationary state, and the blade does not flutter;

[0072] Then execute step S110.

[0073] Step S110, the relay works and the ball is fixed.

[0074] Step S120, determining whether the blade is vibrating.

[0075] In the embodiment of the present application, if the blade is in a flutter state, step S130 is performed. If the blade is in a non-flutter state, step S110 is continued to be performed.

[0076] Step S130, the relay does not work and the ball moves freely.

[0077] Step S140, determining whether the temperature is too high.

[0078] In the embodiment of the present application, if the temperature is too high, step S150 is executed. If the temperature is not high, step S130 is continued.

[0079] In step 150 , the heat sink operates to reduce the surface temperature.

[0080] With reference to the above steps S100 to S150 , the control of the entire damper can be achieved.

[0081] In some embodiments, the damper housing 10 is approximately a cube, the heat sink is arranged above the upper outer surface of the damper housing 10 in the thickness direction, and the damper also includes a honeycomb core panel 90, which is arranged on the lower outer surface of the damper housing 10 in the thickness direction. During the operation of the wind turbine, the blade 100 itself will vibrate under the action of the wind load, and the installed damper will inevitably generate additional vibrations due to the flow of the damping fluid and the movement of the rolling ball 30. In order to reduce the secondary vibration of the blade caused by the vibration of the damper, an additional layer of honeycomb core panel 90 with good vibration isolation performance is attached to the position where the damper is installed. According to the difference in the type of core material in the honeycomb core panel 90 (aluminum, carbon fiber, polyester polymer, etc.), the core layer thickness can be selected between 10-20mm. The greater the thickness, the better the vibration isolation performance. However, after reaching a certain critical thickness, the improvement effect is not obvious. Therefore, the core layer thickness is set between 10-20mm. While ensuring good vibration isolation performance, the appropriate thickness of the core layer thickness can ensure the volume of the damper, thereby reducing the weight of the damper.

[0082] Based on the dampers provided in the above embodiments, Figure 4 and Figure 6As shown, the present application also provides a blade for a wind turbine generator set, wherein the blade 100 includes a blade shell and a damper 200 provided in each of the above embodiments, wherein the blade shell includes: a suction surface shell B1 and a pressure surface shell B2, and the damper 200 is arranged inside the blade shell. Therefore, the blade has the beneficial effects of the damper in each of the above embodiments, which will not be described in detail here.

[0083] like Figure 5 As shown, the installation positions on the blade 100 include: the blade tip 101, the blade root 102, the main web 103, the trailing edge small web 104, the trailing edge 105, the leading edge 106, the web 107 and other arbitrary positions. Generally, when the blade flutters, the vibration intensity of the blade tip 101 is relatively large. In theory, installing it at the position of the blade tip 101 has a better suppression effect on the flutter. However, the installation position of the blade tip 101 is limited, and based on safety considerations, the damper can be installed at the leading edge 106, the trailing edge 105 or between the two webs 107 of the blade 100.

[0084] Continue to refer to Figure 6 In some embodiments, the length direction of the damper 200 is arranged along the swing direction F1 of the blade 100, and the width direction of the damper is arranged along the swing direction F2 of the blade 100. When the blade is in flutter, the plurality of rolling balls 30 move along the swing direction F2 in each sub-accommodation cavity, which can effectively suppress the flutter.

[0085] In some embodiments, the damper 200 is mounted on the inner side of the suction surface shell B1 of the blade 100 , near the trailing edge of the blade tip.

[0086] In some embodiments, the total weight of the damper 200 is 4%-7% of the original weight of the blade 100. In the embodiment of the present application, the original weight of the blade 100 is the weight of the blade before the damper 200 is installed.

[0087] In the blade for a wind turbine provided in the embodiment of the present application, the damper 200 is too heavy, which makes the operating load of the blade 100 too heavy, and there is a safety hazard when the blade 100 is in operation. The damper 200 is too light and the damping effect is not good. When the blade 100 flutters, the vibration suppression effect is not obvious, which may cause damage to the blade 100 and its surrounding structures.

[0088] Based on the blades for wind turbines provided in the above embodiments, the present application further provides a wind turbine, which includes the dampers provided in the above embodiments, and / or the blades for wind turbines provided in the above embodiments. Therefore, the dampers and the blades for wind turbines provided in the above embodiments have the beneficial effects, which will not be described in detail here.

[0089] 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 application without departing from the spirit and scope of the present application. However, it should be understood that, in the opinion of those skilled in the art, these modifications and variations will still fall within the spirit and scope of the embodiments of the present application defined by the claims.

Claims

1. A damper, characterized in that: The damper comprises: A damper housing (10) forming a receiving chamber (11) for receiving damping fluid; A plurality of curved partitions (20) extending along the width direction of the accommodating cavity (11) and arranged at intervals in the length direction of the accommodating cavity (11) to divide the accommodating cavity (11) into a plurality of sub-accommodating cavities, wherein the curved partitions (20) are provided with through holes so that the sub-accommodating cavities are interconnected; A plurality of rolling balls (30), wherein the rolling balls (30) are made of a magnetic material and are arranged in each sub-accommodating cavity; An electromagnet assembly (40), the electromagnet assembly (40) comprising: an electromagnetic relay (41), arranged on the outer side surface of the damper housing (10) in the width direction, and used to control the restraint state of the rolling ball (30); when the electromagnet assembly (40) is working, it generates a magnetic field to adsorb the rolling ball (30) onto the inner side surface of the damper housing (10), thereby locking the rolling ball (30).

2. The damper according to claim 1, characterized in that The electromagnet assembly (40) further comprises: a steel baffle (42) arranged on the outer side surface of the damper housing (10) along the length direction of the damper housing (10), wherein the electromagnetic relay (41) is arranged on the steel baffle (42).

3. The damper according to claim 2, characterized in that: The damper also includes a controller and a vibration sensor (60); When the vibration sensed by the vibration sensor (60) is lower than a predetermined value, the controller controls the electromagnetic relay (41) to operate, so that the steel baffle (42) is magnetized, thereby adsorbing the rolling ball (30) to the inner wall surface of the damper housing (10) close to the steel baffle (42); when the vibration is equal to or greater than the predetermined value, the electromagnetic relay (41) stops operating to release the rolling ball (30).

4. The damper according to claim 1, characterized in that: The damper housing (10) is approximately a cube, and the damper further comprises a honeycomb core material panel (90) which is arranged on the lower outer surface of the damper housing (10) in the thickness direction.

5. The damper according to claim 1, characterized in that: The damper housing (10) is also provided with a pouring port (12) for pouring the damping fluid into the accommodating chamber (11); the diameter of the rolling ball (30) is 20%-30% of the distance between two adjacent curved partitions (20); the diameter of the rolling ball (30) is greater than the diameter of the through hole; the magnetic material comprises iron, nickel or cobalt; the material of the rolling ball (30) further comprises rubber, which is coated on the outer surface of the rolling ball (30).

6. The damper according to claim 1, characterized in that The damper also includes a damping fluid located in the accommodating chamber (11), the damping fluid accounting for 80%-90% of the capacity of the accommodating chamber (11), and at a standard atmospheric pressure of 25 o C, the viscosity of the damping fluid ranges from 300 to 500 centipoise.

7. A blade for a wind turbine generator set, characterized in that: The blade (100) comprises a blade shell and a damper according to any one of claims 1 to 6, wherein the damper (200) is arranged inside the blade shell.

8. The blade for a wind turbine generator set according to claim 7, characterized in that: The length direction of the damper (200) is arranged along the flapping direction (F1) of the blade (100), and the width direction of the damper (200) is arranged along the swinging direction (F2) of the blade (100).

9. The blade for a wind turbine generator set according to claim 8, characterized in that: The damper (200) is installed on the leading edge, the trailing edge or between two webs of the blade (100).

10. The blade for a wind turbine generator set according to claim 7, characterized in that: The damper (200) is installed on the inner side of the suction surface shell of the blade (100), close to the trailing edge of the blade tip.

11. The blade for a wind turbine generator set according to claim 7, characterized in that: The total weight of the damper (200) is 4%-7% of the original weight of the blade (100).

12. A wind turbine generator set, characterized in that: The wind turbine generator set comprises the damper according to any one of claims 1 to 6, or the blade for a wind turbine generator set according to any one of claims 7 to 11.

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