A fan variable frequency suspension vibration reduction device

Abstract

The utility model discloses a variable frequency suspension vibration reduction device for a wind turbine, comprising a mass body in a wind turbine tower, the outer periphery of the mass body being connected to the inner wall of the wind turbine tower through a plurality of dampers, the top of the mass body being connected to the top of the wind turbine tower through an upper cable, and the bottom of the mass body being connected to a tension control device through a lower cable. The utility model utilizes the resonance effect to accumulate the small displacement vibration energy at the top of the tower into the large displacement movement energy of the mass body; utilizes the tension to change the natural frequency of the device to realize variable frequency vibration reduction control; is suitable for the actual situation that the internal space of the wind turbine tower is small at the top and large at the bottom; has a simple structure, is easy to maintain, and is convenient to replace components.

Description

Technical Field

[0001] The utility model relates to the field of machinery, in particular to a fan variable frequency suspension vibration reduction device. Background Art

[0002] A wind turbine usually consists of three parts: the upper part, the blades, the steel structure tower in the middle, and the reinforced concrete foundation in the lower part. When the blades rotate, the tower swings back and forth. The reciprocating action over the years causes the wind turbine structure to be subjected to alternating stress, which leads to fatigue damage and safety accidents. Before the fatigue damage of the structural parts occurs, reducing the swing amplitude of the tower through vibration reduction devices and reducing the amplitude of alternating stress borne by the structure is an effective way to avoid or delay structural fatigue damage, but no relevant devices have been found so far. Utility Model Content

[0003] In order to solve the above technical problems, the utility model proposes a fan variable frequency suspension vibration reduction device.

[0004] The purpose of the utility model is achieved through the following technical solutions:

[0005] A variable frequency suspension vibration reduction device for a wind turbine comprises a mass body in a wind turbine tower, wherein the outer periphery of the mass body is connected to the inner wall of the wind turbine tower via a plurality of dampers, the top of the mass body is connected to the top of the wind turbine tower via an upper cable, and the bottom of the mass body is connected to a tension control device via a lower cable.

[0006] As a further improvement, there are at least two dampers and the straight line where the lengths of the two dampers are located is arranged horizontally and the rotating surface of the fan blades is vertical.

[0007] As a further improvement, the tension control device is a pneumatic cylinder, an electric cylinder or a winch.

[0008] As a further improvement, the damper is a viscous damper.

[0009] As a further improvement, the tension control device is communicatively connected to a main control system of the fan.

[0010] According to a further improvement, the mass body is located in the lower region of the wind turbine tower.

[0011] As a further improvement, both ends of the damper are connected to the mass body and the inner wall of the wind turbine tower through ball joints respectively.

[0012] The beneficial effects of the utility model are:

[0013] By utilizing the resonance effect, the small displacement vibration energy at the top of the tower is accumulated into the large displacement kinetic energy of the mass body; the natural frequency of the device is changed by utilizing the pulling force to realize variable frequency vibration reduction control; it is suitable for the actual situation that the internal space of the wind turbine tower is small at the top and large at the bottom; it has a simple structure, is easy to maintain, and convenient to replace parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention is further described with reference to the accompanying drawings, but the contents in the accompanying drawings do not constitute any limitation to the present invention.

[0015] Figure 1 The overall structural diagram of the fan is shown in FIG.

[0016] Figure 2 This is a structural schematic diagram of a fan variable frequency suspension vibration reduction device;

[0017] Figure 3 Schematic diagram of the connection structure between the mass body and the damper. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and examples. Example 1

[0019] like Figure 1 and Figure 2 The wind turbine variable frequency suspension vibration reduction device shown includes a wind turbine tower 1, a mass body 2, a damper 3, an upper cable 4, a lower cable 5 and a tension control device 6.

[0020] The mass body 2 is located at the lower part of the wind turbine tower 1, the top of the mass body 2 is connected to the top of the wind turbine tower 1 through the upper cable 4, and the bottom of the mass body 2 is connected to the tension control device 6 through the lower cable 5. The two sides of the mass body 2 are connected to the inner wall of the wind turbine tower 1 through the damper 3, preferably, the straight line where the center axis of the damper 3 is located is horizontally arranged and perpendicular to the rotating plane of the wind turbine. Thus, the swing of the mass body 2 can have a larger range.

[0021] The principle is as follows: when the blades rotate, the tower swings. When the natural frequency of the suspension system (mass body, cable) is close to the tower swing frequency, a resonance effect is formed, that is, the continuous small swing of the top of the tower will cause the mass body to swing sharply. This large swing causes the viscous dampers on both sides of the mass body to expand and contract to a large extent, forming an energy dissipation mechanism, thereby reducing the swing of the tower.

[0022] The frequency of tower swing is related to the blade speed, and the blade speed of the wind turbine will change with the wind speed. In order to achieve the variability of the suspension system frequency, a tension control device is set at the lower part of the lower cable. The tension device is connected to the main control data of the wind turbine and adjusts the tension of the lower cable according to the speed of the wind turbine blades. According to the principle of dynamics, the greater the tension, the greater the natural frequency of the suspension system, and vice versa. The tension size is linked to the blade speed to ensure that the natural frequency of the suspension system is always close to the tower swing frequency, thereby achieving a vibration reduction effect under various working conditions.

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit the protection scope of the utility model. Although the utility model is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the utility model.

Claims

1. A fan variable frequency suspension vibration reduction device, characterized in that: The invention comprises a mass body (2) located in a wind turbine tower (1), wherein the outer periphery of the mass body (2) is connected to the inner wall of the wind turbine tower (1) via a plurality of dampers (3), the top of the mass body (2) is connected to the top of the wind turbine tower (1) via an upper cable (4), and the bottom of the mass body (2) is connected to a tension control device (6) via a lower cable (5).

2. The fan variable frequency suspension vibration reduction device according to claim 1, characterized in that: There are at least two dampers (3), and the straight line on which the lengths of the two dampers (3) lie is arranged horizontally and perpendicular to the rotation plane of the fan blades.

3. The fan variable frequency suspension vibration reduction device according to claim 2, characterized in that: The tension control device (6) is a pneumatic cylinder, an electric cylinder or a winch.

4. The fan variable frequency suspension vibration reduction device according to claim 1, characterized in that: The damper (3) is a viscous damper.

5. The fan variable frequency suspension vibration reduction device according to claim 1, characterized in that: The tension control device (6) is communicatively connected to the main control system of the fan.

6. The fan variable frequency suspension vibration reduction device according to claim 1, characterized in that: The mass body (2) is located in the lower area of ​​the wind turbine tower (1).

7. The fan variable frequency suspension vibration reduction device according to claim 1, characterized in that: Two ends of the damper (3) are respectively connected to the mass body (2) and the inner wall of the wind turbine tower (1) through ball joints.

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