Multi-viscous damper coupling mass block damping device suitable for wind power tower

Abstract

The invention relates to the field of tower vibration reduction, in particular to a multi-viscous damper coupling mass block vibration reduction device suitable for a wind power tower, which comprises a mass block, two groups of viscous dampers distributed above and below the mass block and two annular mounting frames, the annular mounting frames are connected with the inner wall of the tower, and the mass block is connected with the annular mounting frames through the viscous dampers; each group of viscous dampers comprises N viscous dampers, the N viscous dampers are uniformly distributed in the circumferential direction of the mass block and are annularly and symmetrically distributed around the central axis of the mass block, and the circumferential interval angle between connecting lines of the axes of the adjacent viscous dampers and the center of the mass block is 360 degrees / N. By the adoption of the technical scheme, the multi-direction damping effect of the wind power tower can be achieved.

Description

Technical Field

[0001] This invention relates to the field of tower vibration reduction, and more specifically to a multi-viscous damper coupled mass block vibration reduction device suitable for wind turbine towers. Background Technology

[0002] As wind turbines rapidly develop towards larger sizes and deeper offshore applications, the external load environment borne by their supporting structures is becoming increasingly complex, including wind-induced vibration, wave impact, seismic disturbances, and periodic loads generated during turbine operation. These complex loads often exhibit characteristics such as large amplitude, variable direction, and long duration, easily inducing excessive vibration and localized stress concentration in the tower structure, leading to weld fatigue cracking, increased risk of tower buckling, and a greater likelihood of overall turbine resonance. Traditional structural reinforcement measures, such as increasing wall thickness, improving material strength, or adding stiffening rings, while improving overall stiffness to some extent, are costly and significantly increase weight, failing to fundamentally suppress the tower's dynamic response. Therefore, researching efficient, lightweight, and adjustable damping vibration reduction devices installed on the inner wall of the tower has become an important direction for improving the structural toughness of wind turbine towers.

[0003] Among numerous vibration reduction technologies, viscous dampers are widely used in bridges, high-rise buildings, and energy equipment structures due to their excellent energy dissipation capabilities and wide adaptability. Their basic principle is to convert the kinetic energy of structural vibration into heat energy and dissipate it through the viscous shearing action generated by the damping medium during piston-like motion, thereby effectively reducing the amplitude of the structural response. However, relying solely on the damping effect of viscous dampers is still insufficient to fully regulate the structural dynamic characteristics, especially in flexible, highly coupled systems such as wind turbine towers, where the structural frequency and excitation frequency are often coupled. A single damping mechanism cannot simultaneously meet the control requirements of multiple vibration modes and the vibration reduction effect in multiple directions. Summary of the Invention

[0004] The present invention aims to provide a multi-viscous damper coupled mass block vibration reduction device suitable for wind turbine towers to achieve multi-directional vibration reduction effect.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a multi-viscous damper coupled mass block vibration reduction device suitable for wind turbine towers, comprising a mass block, two sets of viscous dampers distributed above and below the mass block, and two annular mounting frames. The annular mounting frames are connected to the inner wall of the tower, and the mass block is connected to the annular mounting frames through the viscous dampers. Each set of viscous dampers includes N viscous dampers, which are evenly distributed around the circumference of the mass block and are symmetrically distributed in a ring around the central axis of the mass block. The circumferential interval angle between the lines connecting the axes of adjacent viscous dampers and the center of the mass block is 360° / N.

[0006] The beneficial effects of this plan are: 1. This invention forms a composite tuning system by arranging multiple viscous dampers vertically and vertically with a central mass block, ensuring that the device has superior vibration reduction performance in multiple directions such as vertical, radial and tangential directions. It can effectively cope with dynamic loads with uncertain directions such as wind, waves and earthquakes. The vibration response amplitude at the top of the tower can be reduced by 30%-50% compared with traditional single damping devices, significantly improving the overall vibration resistance and operational stability.

[0007] 2. The synergistic effect between the viscous damper and the mass block organically combines the inertial tuning effect with the viscous energy dissipation process. The internal damping fluid generates strong shear and throttling losses during the piston's reciprocating motion, thereby achieving more efficient vibration energy dissipation. Compared with traditional single viscous damping systems, the energy dissipation path of this invention is more concentrated and more efficient, and the system can significantly suppress both first-order and second-order modal vibrations.

[0008] 3. By adjusting the mass of the mass block and the damping coefficient of the viscous damper, precise matching between the device frequency and the tower's natural frequency can be achieved, thereby maintaining optimal tuning and vibration reduction effects under different unit capacities, tower heights, and operating conditions. This adjustable characteristic gives the device greater adaptability, allowing it to be flexibly configured according to the dynamic characteristics of the tower structure.

[0009] 4. This invention employs a modular design and a ring-shaped support installation structure, significantly reducing the overall weight and space occupation of the device, while simplifying on-site installation and subsequent maintenance. The device has a compact structure and standardized interfaces, allowing for rapid integration during wind turbine tower manufacturing or operation, effectively controlling manufacturing and maintenance costs, and improving the economy and reliability of the equipment throughout its life cycle.

[0010] Furthermore, the mass block and the ring mounting bracket are located at the point of maximum displacement of the first or second mode of the wind turbine tower, and their weight accounts for 0.025%-1% of the total weight of the wind turbine tower. The total weight of the mass block and the two sets of viscous dampers is less than or equal to 2% of the total weight of the wind turbine tower.

[0011] Furthermore, two viscous dampers located diagonally above and below the mass block are arranged in parallel.

[0012] Furthermore, the viscous damper includes a first connecting part, a damper body, and a second connecting part, which are connected in sequence and used to connect the mass block and the annular mounting frame. The damper body includes a damping outer cylinder, a piston rod, a piston block, damping fluid, and a cap. The cap is fixedly connected to one end of the opening of the damping outer cylinder. The piston rod is fixedly connected to the piston block and slidably connected to the cap. The piston block is slidably disposed inside the damping outer cylinder and has a throttling orifice on it, through which the damping fluid can flow in the damping outer cylinder. One end of the first connecting part is fixedly connected to the piston rod, and the other end of the first connecting part is hinged to the mass block. One end of the second connecting part is fixedly connected to the damping outer cylinder, and the other end of the second connecting part is hinged to the annular mounting frame.

[0013] Furthermore, the mass block is covered with a vibration-damping rubber layer, and an elastic vibration-damping washer is provided between the annular mounting frame and the inner wall of the tower.

[0014] Furthermore, the outer diameter of the mass block is 8%-12% of the inner diameter of the tower, and the thickness of the mass block is 0.5-1 times the outer diameter of the mass block; the length of the viscous damper is 0.6-0.8 times the inner diameter of the tower, the outer diameter of the viscous damper is 3%-5% of the inner diameter of the tower, and the stroke range of the viscous damper is ±50mm-±150mm; the thickness of the annular mounting bracket is 0.5-1 times the thickness of the tower wall.

[0015] Furthermore, N is a positive integer between 4 and 6.

[0016] Furthermore, both the first and second connecting parts include a connecting strip and a connecting plate. The connecting plate is fixedly connected to the mass block or the annular mounting bracket. One end of the connecting strip is fixedly connected to the piston rod or the damping outer cylinder, and the other end of the connecting strip is hinged to the connecting plate.

[0017] In summary, the beneficial effects of this scheme are as follows: the device, through the inertial tuning effect of the added mass block, makes its frequency close to the first or second order vibration frequency of the tower, thus working in conjunction with the viscous damper to achieve active energy absorption and dissipation of the main vibration mode. The viscous damper undertakes the main function of energy dissipation in the system, while the mass block provides inertial tuning support, enabling the entire device to possess high damping, high response sensitivity, and wide-frequency vibration reduction characteristics. This composite damping technology can not only effectively reduce tower top displacement and acceleration response, but also significantly improve tower fatigue life and safety margin, providing an economical, reliable, and suitable vibration reduction solution for large wind turbine units in complex marine environments.

[0018] Applying this multi-viscous damper coupled mass block vibration reduction device to the interior of wind turbine towers can significantly reduce the horizontal displacement and acceleration response at the tower top, with vibration reduction amplitudes reaching 30%-50% and structural fatigue life increased by 15%-25%. This invention can be considered a composite system of viscous damping and inertial tuning. Through the synergistic action of multiple viscous dampers in two sets (upper and lower), it covers vibration modes of the structure in different directions, achieving efficient multi-directional, wide-frequency vibration reduction of the tower. The device is compact, has adjustable damping, and is easy to install, making it particularly suitable for the wind and seismic resistance design of large-capacity, high-tower, and tall wind turbines, demonstrating significant engineering application value and promotional significance.

[0019] Furthermore, the first connecting part located above the mass block includes a connecting piece and a connecting block. The connecting block is fixedly connected to the mass block, one end of the connecting piece is fixedly connected to the piston rod, and the other end of the connecting piece is hinged to the connecting block. The first connecting part located below the mass block includes a connecting rod. One end of the connecting rod is fixedly connected to the piston rod, and the other end of the connecting rod is spherically hinged to the mass block. The second connecting parts located above and below the mass block both include connecting blocks and connecting members. The connecting block is fixedly connected to the annular mounting bracket. The connecting member includes a first connecting rod, a connecting body, and a second connecting rod. The first connecting rod is fixedly connected to the damping outer cylinder, and the second connecting rod is spherically hinged to the connecting block. A gap is left between the first connecting rod and the second connecting rod. The connecting body includes a screw provided on the first connecting rod or the second connecting rod and a threaded hole provided on the second connecting rod or the first connecting rod that is threadedly connected to the screw.

[0020] The beneficial effects of this solution are as follows: This technical solution further facilitates the installation and maintenance of the vibration damping device, while improving the vibration damping effect. Specifically, compared to the method where the connecting plates and connecting blocks are hinged together by pins and then all connecting plates are bolted to the mass block or ring mounting bracket, the ball joints between the connecting rod and the mass block, as well as the ball joints between the second connecting rod and the connecting block, improve installation efficiency and disassembly and maintenance efficiency. Furthermore, the gap between the first and second connecting rods provides room for thermal expansion and contraction in marine environments with large diurnal temperature variations. Since the viscous damper is required to be in a neutral position when stationary, ensuring that each viscous damper simultaneously enters the working state within a ±5% error range ensures that the mass block is in equilibrium and can respond freely in any direction. Without the gap, thermal expansion and contraction would affect the position of the viscous damper when stationary, thus affecting the vibration damping effect.

[0021] The connector design also corrects for tower machining errors or on-site installation errors, ensuring that the mass block is centered on the tower. For example, if there are uneven defects on the symmetrical inner wall of the tower, and the mass block is not centered after the viscous damper is installed, the length of the damping rod can be adjusted to center the mass block and offset the error. On the one hand, wind turbine towers are thin-walled conical structures with relatively weak radial stiffness. If the mass block deviates from the radial geometric center, its own mass and inertial force during vibration will form a radial eccentric load, continuously generating additional bending moments during tower vibration. This leads to unilateral compression and tension on the tower wall, exacerbating local stress concentration and potentially causing weld cracking or material fatigue in the long term. By ensuring the mass block is centered on the radial geometric center, its gravity and inertial force are symmetrically distributed radially along the tower, completely offsetting the radial eccentric bending moment and ensuring that the vibration damping device does not impose additional mechanical burden on the tower structure, perfectly matching the stress characteristics of the tower body. On the other hand, during the radial reciprocating motion, the vibration energy is dissipated through the cooperation of the mass block and the viscous damper. When the mass block is located at the radial geometric center, its motion trajectory is completely coincident with the design axis of the viscous damper, which can ensure that the damping rod is subjected to uniform force and avoid damping force fluctuations, component jamming or wear caused by trajectory deviation. If it deviates from the center, the viscous damper will bear additional lateral force, which will not only reduce energy dissipation efficiency, but also shorten the service life of the damping component. This is especially critical for offshore working conditions with high salt spray and strong vibration. On the other hand, when offshore wind turbine towers are subjected to irregular wind loads and wave loads, in addition to bending vibration, they will also be accompanied by slight torsional vibration. The symmetrical arrangement of the mass block at the radial geometric center can make the viscous damper respond consistently to the vibration in all directions of the tower's circumference, and offset the energy of torsional vibration through symmetrical inertial force. If the mass block deviates from the center, the inertial force of the viscous damper will be biased to one side, which may amplify the torsional vibration and exacerbate the dynamic load on the tower. Attached Figure Description

[0022] Figure 1 This is a three-dimensional diagram of Embodiment 1 of the present invention; Figure 2 This is a three-dimensional diagram of Embodiment 2 of the present invention.

[0023] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings include: mass block 1, damping outer cylinder 2, piston rod 3, connecting bar 4, connecting plate 5, connecting rod 6, first connecting rod 7, second connecting rod 8, and screw 9. Detailed Implementation

[0024] Example 1 like Figure 1The multi-viscous damper coupled mass block vibration reduction device for wind turbine towers shown includes a mass block 1, two sets of viscous dampers distributed above and below the mass block 1, and two annular mounting frames. The annular mounting frames are used for bolt connection to the inner wall of the tower and are not shown in the figure. The mass block 1 is connected to the annular mounting frames through the viscous dampers. The mass block 1 and the annular mounting frames are located at the point of maximum displacement of the first or second vibration mode of the wind turbine tower. Their weight accounts for 0.025%-1% of the total weight of the wind turbine tower. The total weight of the mass block 1 and the two sets of viscous dampers is less than or equal to 2% of the total weight of the wind turbine tower.

[0025] Each group of viscous dampers includes N viscous dampers, where N is a positive integer from 4 to 6. In this embodiment, N is 4. The four viscous dampers are evenly distributed around the circumference of the mass block 1 and are symmetrically distributed in a ring around the central axis of the mass block 1. The circumferential interval angle between the line connecting the axis of the adjacent viscous damper and the center of the mass block 1 is 360° / N. The two viscous dampers located at the upper and lower diagonals of the mass block 1 are arranged in parallel. The central axis of the mass block 1 coincides with or is parallel to the central axis of the tower.

[0026] The viscous damper includes a first connecting part, a damper body, and a second connecting part, which are connected in sequence to connect the mass block 1 and the annular mounting bracket. The damper body includes a damping outer cylinder 2, a piston rod 3, a piston block, damping fluid, and a cap. The cap is fixedly connected to one end of the opening of the damping outer cylinder 2, for example, by welding. The piston rod 3 is fixedly connected to the piston block and slidably connected to the cap. The piston block is slidably disposed inside the damping outer cylinder 2 and has a throttling orifice on it, through which the damping fluid can flow in the damping outer cylinder 2. Both the first and second connecting parts include a connecting strip 4 and a connecting plate 5. The connecting plate 5 is fixedly connected to the mass block 1 or the annular mounting bracket, for example, by bolting. One end of the connecting strip 4 is fixedly connected to the piston rod 3 or the damping outer cylinder 2, and the other end of the connecting strip 4 is hinged to the connecting plate 5 by a pin to form an anti-torsion limiting form.

[0027] When the wind turbine tower vibrates under wind, wave, or seismic loads, mass block 1 vibrates in the opposite direction to the tower's motion due to inertia. This causes the piston rod 3 of the viscous damper to reciprocate. As the damping fluid flows on both sides of the piston, it generates damping force through shear deformation of the throttling orifice, converting the structural vibration energy into internal frictional heat and dissipating it. Under inertial tuning, mass block 1 can approach the first or second order vibration frequency of the tower, thus achieving a dual vibration reduction effect of resonant absorption and damping dissipation of vibration energy.

[0028] The damping coefficient of the viscous damper can be adjusted by changing the internal liquid viscosity or adjusting the orifice size to adapt to different tower frequencies and excitation characteristics. The outer damping cylinder 2 can be made of alloy steel or carbon fiber reinforced composite material, possessing good fatigue resistance and corrosion resistance, suitable for long-term service in high-humidity marine environments. The damping fluid can be high-viscosity silicone oil, ethylene glycol, or other temperature-resistant viscous liquids as the working medium. Its viscosity coefficient can be designed and adjusted according to the frequency characteristics of different tower vibration modes, with a typical range of 5*10. 5 -1*10 7 N*s / m. A sealing ring and dust cover are used between piston rod 3 and the cover to prevent liquid leakage and external particle intrusion. The viscous damper length is 0.6-0.8 times the tower's inner diameter, and the outer diameter is 3%-5% of the tower's inner diameter. The stroke range of the viscous damper is ±50mm-±150mm, which can fully meet the tower's maximum relative displacement requirements under strong wind or earthquake conditions.

[0029] Mass block 1 is made of high-density material, preferably steel, lead, or tungsten alloy. Its shape can be cylindrical, cubic, or polygonal. Mass block 1 can be covered with a vibration-damping rubber layer, or its outer surface can be sprayed with a corrosion-resistant protective coating. The interior can be pre-set with a tuning cavity to fill with counterweight materials of different densities as needed, so as to achieve precise tuning of the device's natural frequency. The outer diameter of mass block 1 is 8%-12% of the inner diameter of the tower, and the thickness of mass block 1 is 0.5-1 times the outer diameter of mass block 1. An elastic vibration-damping washer can be set between the annular mounting frame and the inner wall of the tower. The annular mounting frame can be made of Q345 or Q390 steel, and its thickness is 0.5-1 times the thickness of the tower wall.

[0030] Example 2 The difference between Embodiment 2 and Embodiment 1 is that the second connecting part is different. Of course, the first connecting part located below the mass block 1 can also be set differently from Embodiment 1.

[0031] The first connecting part located above the mass block 1 is the same as in Embodiment 1, including a connecting piece and a connecting block. The connecting block is fixedly connected to the mass block 1, one end of the connecting piece is fixedly connected to the piston rod 3, and the other end of the connecting piece is hinged to the connecting block. The connecting strip 4 in Embodiment 1 and the connecting piece in Embodiment 2 refer to the same object, only the names are different. The connecting plate 5 and the connecting block are also the same.

[0032] The first connecting part located below the mass block 1 can be set in the same way as in Embodiment 1, or it can be set differently. For example, the first connecting part located below the mass block 1 includes a connecting rod 6. One end of the connecting rod 6 is fixedly connected to the piston rod 3, and the other end of the connecting rod 6 is spherically hinged to the mass block 1. That is, the end of the connecting rod 6 can be set in a hemispherical shape and hinged to the upper hemispherical mounting hole of the mass block 1.

[0033] The difference between Embodiment 2 and Embodiment 1 is that the second connecting part located above and below the mass block 1 includes a connecting block and a connecting member. The connecting block is bolted to the annular mounting bracket. The connecting member includes a first connecting rod 7, a connecting body, and a second connecting rod 8. The first connecting rod 7 is welded and fixedly connected to the damping outer cylinder 2. The second connecting rod 8 is spherically hinged to the connecting block, that is, the end of the second connecting rod 8 can also be hemispherical and hinged to the hemispherical mounting hole on the connecting block. There is a gap between the first connecting rod 7 and the second connecting rod 8. The connecting body includes a screw 9 on the first connecting rod 7 or the second connecting rod 8 and a threaded hole on the second connecting rod 8 or the first connecting rod 7 that is threaded to the screw 9. In this embodiment, the screw 9 is on the second connecting rod 8 and the threaded hole on the first connecting rod 7 that is threaded to the screw 9. The screw 9 can be welded to the second connecting rod 8 or formed by extending the second connecting rod 8. The threaded hole is long enough to allow the first connecting rod 7 and the second connecting rod 8 to contact.

[0034] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A vibration reduction device for multi-viscous dampers coupled with mass blocks suitable for wind turbine towers, characterized in that: It includes a mass block, two sets of viscous dampers distributed above and below the mass block, and two annular mounting frames. The annular mounting frames are connected to the inner wall of the tower, and the mass block is connected to the annular mounting frames through the viscous dampers. Each set of viscous dampers includes N viscous dampers, which are evenly distributed around the circumference of the mass block and are symmetrically distributed in a ring around the central axis of the mass block. The circumferential interval angle between the lines connecting the axes of adjacent viscous dampers and the center of the mass block is 360° / N.

2. The vibration reduction device for multi-viscous dampers coupled with mass blocks suitable for wind turbine towers according to claim 1, characterized in that: The mass block and the ring mounting bracket are located at the point of maximum displacement of the first or second mode of vibration of the wind turbine tower. Their weight accounts for 0.025%-1% of the total weight of the wind turbine tower. The total weight of the mass block and the two sets of viscous dampers is less than or equal to 2% of the total weight of the wind turbine tower.

3. The vibration reduction device for multi-viscous dampers coupled with mass blocks suitable for wind turbine towers according to claim 2, characterized in that: Two viscous dampers are set in parallel at opposite corners of the mass block.

4. The vibration reduction device for multi-viscous dampers coupled with mass blocks suitable for wind turbine towers according to claim 3, characterized in that: The viscous damper includes a first connecting part, a damper body, and a second connecting part, which are connected in sequence to connect a mass block and an annular mounting frame. The damper body includes a damping outer cylinder, a piston rod, a piston block, damping fluid, and a cap. The cap is fixedly connected to one end of the opening of the damping outer cylinder. The piston rod is fixedly connected to the piston block and slidably connected to the cap. The piston block is slidably disposed inside the damping outer cylinder and has a throttling orifice, through which the damping fluid can flow in the damping outer cylinder. One end of the first connecting part is fixedly connected to the piston rod, and the other end of the first connecting part is hinged to the mass block. One end of the second connecting part is fixedly connected to the damping outer cylinder, and the other end of the second connecting part is hinged to the annular mounting frame.

5. The vibration reduction device for multi-viscous dampers coupled with mass blocks suitable for wind turbine towers according to claim 4, characterized in that: The mass block is covered with a vibration-damping rubber layer, and an elastic vibration-damping washer is provided between the annular mounting frame and the inner wall of the tower.

6. The vibration reduction device for multi-viscous dampers coupled with mass blocks suitable for wind turbine towers according to claim 5, characterized in that: The outer diameter of the mass block is 8%-12% of the inner diameter of the tower, and the thickness of the mass block is 0.5-1 times the outer diameter of the mass block; the length of the viscous damper is 0.6-0.8 times the inner diameter of the tower, the outer diameter of the viscous damper is 3%-5% of the inner diameter of the tower, and the stroke range of the viscous damper is ±50mm-±150mm; the thickness of the annular mounting bracket is 0.5-1 times the thickness of the tower wall.

7. The multi-viscous damper coupled mass block vibration reduction device for wind turbine towers according to claim 6, characterized in that: N is a positive integer between 4 and 6.

8. The multi-viscous damper coupled mass block vibration reduction device for wind turbine towers according to any one of claims 4 or 7, characterized in that: Both the first and second connecting parts include a connecting strip and a connecting plate. The connecting plate is fixedly connected to the mass block or the annular mounting bracket. One end of the connecting strip is fixedly connected to the piston rod or the damping outer cylinder, and the other end of the connecting strip is hinged to the connecting plate.

9. The multi-viscous damper coupled mass block vibration reduction device for wind turbine towers according to any one of claims 4 or 7, characterized in that: The first connecting part located above the mass block includes a connecting piece and a connecting block. The connecting block is fixedly connected to the mass block. One end of the connecting piece is fixedly connected to the piston rod, and the other end of the connecting piece is hinged to the connecting block. The first connecting part located below the mass block includes a connecting rod. One end of the connecting rod is fixedly connected to the piston rod, and the other end of the connecting rod is spherically hinged to the mass block. The second connecting parts located above and below the mass block both include connecting blocks and connecting components. The connecting blocks are fixedly connected to the annular mounting bracket. The connecting components include a first connecting rod, a connecting body, and a second connecting rod. The first connecting rod is fixedly connected to the damping outer cylinder, and the second connecting rod is spherically hinged to the connecting block. A gap is left between the first connecting rod and the second connecting rod. The connecting body includes a screw rod provided on the first connecting rod or the second connecting rod and a threaded hole provided on the second connecting rod or the first connecting rod that is threadedly connected to the screw rod.

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