阅读说明：本技术 大型风力机叶片十字弹性抗振抗损装置及大型风力机叶片 (Cross elastic vibration and damage resisting device for large wind turbine blade and large wind turbine blade ) 是由 胡丹梅 曾理 潘卫国 商洪涛 邓立巍 于 2021-09-26 设计创作，主要内容包括：本发明涉及一种大型风力机叶片十字弹性抗振抗损装置及大型风力机叶片,其中振抗损装置包括支撑体、第一弹簧、第二弹簧、第三弹簧和第四弹簧,第一弹簧、第二弹簧、第三弹簧和第四弹簧的一端分别连接至支撑体,所有弹簧和支撑体在一个平面上,且第一弹簧和第三弹簧的方向相同,第二弹簧和第四弹簧在一条直线上并与第一弹簧垂直,第一弹簧、第二弹簧、第三弹簧和第四弹簧的另一端上均设有用于连接风力机叶片内壁的连接件。与现有技术相比,本发明具有提高叶尖部抗振抗损能力等优点。(The invention relates to a large-scale wind turbine blade cross-shaped elastic anti-vibration and anti-damage device and a large-scale wind turbine blade, wherein the vibration and anti-damage device comprises a supporting body, a first spring, a second spring, a third spring and a fourth spring, one end of the first spring, one end of the second spring, one end of the third spring and one end of the fourth spring are respectively connected to the supporting body, all the springs and the supporting body are arranged on the same plane, the directions of the first spring and the third spring are the same, the second spring and the fourth spring are arranged on the same straight line and are vertical to the first spring, and connecting pieces used for connecting the inner wall of the wind turbine blade are arranged at the other ends of the first spring, the second spring, the third spring and the fourth spring. Compared with the prior art, the invention has the advantages of improving the vibration resistance and damage resistance of the blade tip part and the like.)

1. The utility model provides a large-scale wind turbine blade cross elasticity anti vibration loss resistance device, a serial communication port, including supporter (10), first spring (6), second spring (8), third spring (12) and fourth spring (13), the one end of first spring (6), second spring (8), third spring (12) and fourth spring (13) is connected to supporter (10) respectively, all springs and supporter are on a plane, and the direction of first spring (6) and third spring (12) is the same, second spring (8) and fourth spring (13) are on a straight line and perpendicular with first spring (6), all be equipped with the connecting piece that is used for connecting the wind turbine blade inner wall on the other end of first spring (6), second spring (8), third spring (12) and fourth spring (13).

2. The cross-shaped elastic vibration and damage resisting device for the large wind turbine blade as claimed in claim 1, wherein the connecting pieces on the first spring (6), the second spring (8) and the third spring (12) are cone connecting pieces, and the connecting piece on the fourth spring (13) is a column connecting piece (9).

3. The cross-shaped elastic anti-vibration and anti-damage device for the large-scale wind turbine blade as claimed in claim 1, wherein the first spring (6) and the third spring (12) are in a straight line.

4. The cross-shaped elastic anti-vibration and anti-damage device for the large wind turbine blade as claimed in claim 1, wherein the base stiffness of the first spring (6), the second spring (8), the third spring (12) and the fourth spring (13) is 1500N/m³--20000N/m³。

5. The cross-shaped elastic vibration and damage resisting device for the large-scale wind turbine blade as claimed in claim 4, wherein the base stiffness of the first spring (6), the second spring (8), the third spring (12) and the fourth spring (13) is 10000N/m³。

6. The cross-shaped elastic vibration and damage resisting device for the large-scale wind turbine blade as claimed in claim 1, wherein the supporting body (10) is square.

7. A large wind turbine blade provided with two anti-vibration and anti-damage devices according to any of claims 1-6, parallel to the blade cross-section of the blade.

8. The large wind turbine blade according to claim 8, wherein one of the anti-vibration and anti-damage devices is disposed at 0.47-0.5 of the relative blade height, and the other anti-vibration and anti-damage device is disposed at 0.86-0.91 of the relative blade height.

9. Large wind turbine blade according to claim 7, characterised in that the first spring (6) is attached to the pressure side tip inner wall, the third spring (12) is attached to the suction side tip inner wall and the second spring (8) is attached to the leaflet leading edge inner wall.

10. Large wind turbine blade according to claim 9, characterised in that the fourth spring (13) is attached to the pressure surface inner wall.

Technical Field

The invention relates to a large-scale wind turbine blade and a cross-shaped elastic vibration and damage resisting device thereof.

Background

Since the 21 st century, with the increasing energy problems, the use of wind energy in various countries has reached a rapid development stage. The wind wheel blade is a core component of a wind turbine for converting wind energy into mechanical energy, and the reliability of the wind wheel blade plays an important role in the safe operation of the wind turbine. The wind speed and the wind direction change irregularly, so that the working environment of the wind turbine is very complicated. The wind wheel is exposed to a series of complex loads such as aerodynamic load, centrifugal load, gravity load, etc. for a long time. The tower has its own natural frequency and the operation of the generator generates vibrational frequencies that can cause fatigue damage if the frequency of the blades resonate with any of the frequencies. One of the main factors of blade damage is the resonance phenomenon of the blade, which aggravates the fatigue of the blade material, reduces the effective service life, and even directly causes blade damage and fracture in severe cases. The load borne by the mechanism is amplified due to the resonance phenomenon, the machine body or the blades can shake seriously to influence the power generation efficiency of the machine body or the blades, and the machine body or the blades are damaged seriously, so the structural power design of the blades is particularly critical. Modal analysis is a common method for modern structural dynamic characteristic research and is an important application of a system identification method in the field of engineering vibration. According to the research result of the inherent vibration characteristic, the resonance caused by the fact that the external excitation is the same as the natural vibration frequency can be effectively avoided, and the damage to the mechanical structure is prevented.

Many systematic researches on the natural frequency and the modal shape of the wind turbine have been made at home and abroad. And the additional reinforcement against vibration on the blade structure is also very small. The blade which is the most easily damaged structure in the wind turbine is necessary to reinforce the structure, resist vibration and resist damage, and particularly in a complex environment, the wind turbine blade is likely to resonate with the external environment to cause damage of the wind turbine, so that the service life of the wind turbine is shortened.

Disclosure of Invention

The invention aims to provide a large wind turbine blade cross-shaped elastic vibration-resistant and damage-resistant device and a large wind turbine blade.

The purpose of the invention can be realized by the following technical scheme:

the utility model provides a large-scale wind turbine blade cross elasticity anti vibration loss resistance device, includes supporter, first spring, second spring, third spring and fourth spring, and the one end of first spring, second spring, third spring and fourth spring is connected to the supporter respectively, and all springs and supporters are on a plane, and the direction of first spring and third spring is the same, and second spring and fourth spring are on a straight line and perpendicular with first spring, all be equipped with the connecting piece that is used for connecting wind turbine blade inner wall on the other end of first spring, second spring, third spring and fourth spring.

The connecting pieces on the first spring, the second spring and the third spring are cone connecting pieces, and the connecting piece on the fourth spring is a column connecting piece.

The first spring and the third spring are in a straight line.

The base stiffness of the first spring, the second spring, the third spring and the fourth spring is 1500N/m³--20000N/m³。

The base stiffness of the first spring, the second spring, the third spring and the fourth spring is 10000N/m³。

The support body cube,

A large wind turbine blade is provided with two vibration and damage resisting devices, wherein the vibration and damage resisting devices are parallel to the blade section of the blade.

One anti-vibration and anti-damage device is arranged at the position of 0.47-0.5 of the relative blade height, and the other anti-vibration and anti-damage device is arranged at the position of 0.86-0.91 of the relative blade height.

The first spring is connected to the inner wall of the top end of the pressure surface, the third spring is connected to the inner wall of the top end of the suction surface, and the second spring is connected to the inner wall of the front edge of the leaf element.

The fourth spring is connected to the inner wall of the pressure surface.

Compared with the prior art, the invention has the following beneficial effects:

1) each wind turbine blade is provided with two cross elastic anti-vibration and anti-damage devices, and modal analysis shows that the natural frequency of the wind turbine blade is improved and is higher than most of the frequency of the environment, so that the possibility of damage of the wind turbine blade caused by resonance is reduced.

2) The wind turbine blade provided with the cross elastic anti-vibration and anti-damage device is found through modal analysis that the maximum deformation of the wind turbine blade during resonance is greatly reduced, so that the wind turbine blade has stronger resonance resistance, the damage of the resonance to the wind turbine blade is reduced, and the service life of the wind turbine is prolonged.

3) Compared with the wind turbine blade which is not additionally provided with the cross elastic anti-vibration and anti-damage device, the maximum deformation of the modal shape of the wind turbine blade which is not additionally provided is positioned at the blade tip, and the maximum deformation of the modal shape of the wind turbine blade which is additionally provided with the cross elastic anti-vibration and anti-damage device moves from the blade tip to the middle part of the blade. Therefore, the most fragile blade tip has enhanced vibration and damage resistance, and the service life of the wind turbine is prolonged.

Drawings

FIG. 1 is a schematic structural diagram of a 5MW wind turbine blade with a cross-shaped elastic anti-vibration and anti-damage device;

FIG. 2 is a schematic view of a blade cross-section;

FIG. 3 is a schematic view of the installation of the anti-vibration and anti-damage apparatus;

fig. 4 is a comparison line graph of maximum deformation amounts of mode frequencies under different spring base rigidities and the front three-order modes and a cross anti-vibration and anti-damage device which is not installed, in a static state of the wind turbine, wherein (a) is a comparison line graph of the first-order mode frequencies under different spring base rigidities and the first-order mode frequencies of the cross anti-vibration and anti-damage device which is not installed, (b) is a comparison line graph of the second-order mode frequencies under different spring base rigidities and the second-order mode frequencies of the cross anti-vibration and anti-damage device which is not installed, in a static state of the wind turbine, and (c) is a comparison line graph of the third-order mode frequencies under different spring base rigidities and the third-order mode frequencies of the cross anti-vibration and anti-damage device which is not installed, in a static state of the wind turbine; (d) comparing the maximum deformation of the front three-order mode under different spring stiffness in the static state of the wind turbine with the maximum deformation of the front three-order mode without the cross-shaped vibration and damage resisting device;

FIG. 5 is a comparison line graph of modal frequencies under different spring base stiffness and maximum deformation of the first three-order mode under rated operation state of the wind turbine and the maximum deformation of the wind turbine without the cross anti-vibration and anti-damage device, the cross-shaped vibration and damage resisting device comprises a cross-shaped vibration and damage resisting device, a cross-shaped vibration and damage resisting device, a cross-shaped damage resisting device and a cross-shaped damage resisting device, a cross-shaped damage resisting device and a cross-shaped damage resisting device, and a cross-shaped device, a cross-shaped damage resisting device, and a cross-shaped damage resisting device, a cross-shaped device, and a cross-shaped device, and a cross-shaped device, and a cross-shaped device;

FIG. 6 shows the spring at 10000N/m³And comparing the maximum deformation of the wind turbine with the maximum deformation of the wind turbine without the cross vibration-resistant damage-resistant device under the static or rated working state of the foundation stiffness with the relative blade height position.

Wherein: 1. the blade comprises a blade main body, 2, an anti-vibration and anti-damage device, 3, an anti-vibration and anti-damage device, 4, 5, 7, a cone connecting piece, 6, a first spring, 8, a second spring, 9, a column connecting piece, 10, a supporting body, 11, a leaf element, 12, a third spring, 13, a fourth spring, A, a leaf element front edge inner wall, B, a suction surface top end inner wall, C, a leaf element rear edge inner wall, D, a leaf element front edge inner wall and a connecting line of the leaf element front edge inner wall, the pressure surface top end inner wall and the suction surface top end inner wall is perpendicularly intersected with a pressure surface one-point inner wall, and E, a pressure surface top end inner wall.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

A cross-shaped elastic anti-vibration and anti-damage device for a large wind turbine blade is shown in figures 1 to 3 and comprises a supporting body 10, a first spring 6, a second spring 8, a third spring 12 and a fourth spring 13, wherein one end of the first spring 6, the second spring 8, the third spring 12 and the fourth spring 13 is connected to the supporting body 10 respectively, all the springs and the supporting body are arranged on the same plane, the directions of the first spring 6 and the third spring 12 are the same, the second spring 8 and the fourth spring 13 are arranged on the same straight line and are perpendicular to the first spring 6, and connecting pieces used for connecting the inner wall of the wind turbine blade are arranged at the other ends of the first spring 6, the second spring 8, the third spring 12 and the fourth spring 13. The support body 10 is cube.

In some embodiments, the connections on the first, second and third springs 6, 8, 12 are tapered connections and the connection on the fourth spring 13 is a post connection 9.

In some embodiments, the first spring 6 and the third spring 12 are in a straight line.

In some embodiments, the base stiffness of the first, second, third and fourth springs 6, 8, 12, 13 is 1500N/m³--20000N/m³. In one embodiment, the base stiffness of the first spring 6, the second spring 8, the third spring 12 and the fourth spring 13 is 10000N/m³。

The large wind turbine blade is provided with two vibration and damage resisting devices, and the vibration and damage resisting devices are parallel to the blade section of the blade. One anti-vibration and anti-damage device is arranged at the position of 0.47-0.5 of the relative blade height, and the other anti-vibration and anti-damage device is arranged at the position of 0.86-0.91 of the relative blade height. The first spring 6 is connected to the inner wall of the top end of the pressure surface, the third spring 12 is connected to the inner wall of the top end of the suction surface, and the second spring 8 is connected to the inner wall of the leading edge of the leaf element. The fourth spring 13 is connected to the pressure surface inner wall.

Specifically, fig. 1 shows a schematic structural diagram of a blade body 1 of a horizontal axis wind turbine and cross-shaped elastic anti-vibration and anti-damage devices 2 and 3, wherein two cross-shaped elastic anti-vibration and anti-damage devices are arranged on one wind turbine blade. Two cross elastic vibration-proof and damage-proof devices are respectively installed at the positions of 0.48 relative blade height and 0.89 relative blade height. The mounting method of the two devices is the same.

Fig. 2 and 3 show a schematic drawing of the leaf element of the invention for mounting a cross-shaped elastic anti-vibration and anti-damage device consisting of four springs 6, 8, 12, 13, a support body 10, three conical links 4, 5, 7 and a column link 9. The chlorophyll outer contour curve ABC is a suction surface, and the chlorophyll outer contour curve AEC is a pressure surface. The chord line is a straight line AC between the front edge point A and the rear edge point C, the inner wall E at the top end of the pressure surface is the point with the farthest vertical distance from the chord line on the inner wall at the top end of the pressure surface, and the inner wall B at the top end of the suction surface is the point with the farthest vertical distance from the chord line on the inner wall of the suction surface. Wherein, the three cone connecting pieces 4, 5 and 7 are respectively positioned on the inner wall B at the top end of the suction surface of the wind turbine blade, the inner wall E at the top end of the pressure surface of the wind turbine blade and the inner wall A of the front edge of the leaf element. The BE is connected, and the perpendicular line passing through the point A as the BE is crossed with the pressure surface at the point D on the inner wall. AD is perpendicular to BE, and D is a point on the inner wall of the pressure surface. A post 9 is used to connect the spring end to the inner wall D. The springs 6, 8, 12, 13 are in a free state, either under pressure or in tension, and the base stiffness of the springs is 1500N/m³--20000N/m³. Wherein the base stiffness is defined as the amount of pressure that produces a base unit normal deformation. The support 10 is a cube of 40X 40 mm. Three cone connecting pieces 4, 5 and 7 are smoothly connected with the inner wall of the wind turbine blade, and springs 6, 8, 12 and 13 are also smoothly and fixedly connected with the four connecting pieces 4, 5, 7 and 9 and the support body 6.

Referring to fig. 3, the springs 6, 8, 12, and 13 are arranged in a cross circumferential direction, so that when the wind turbine blade resonates, the springs 6, 8, 12, and 13 apply a pulling force or a pressing force to the blade to be distorted, so as to prevent the blade from being distorted due to resonance, improve the resonance frequency, reduce the possibility of resonating with the outside, and prolong the service life. At the same time, it is also important that the base stiffness of the springs 6, 8, 12, 13 is at a suitable value, and if the base stiffness of the springs 6, 8, 12, 13 is too low, the springs 6, 8, 12, 13 arranged in the cross circumferential direction will be subjected to lateral distortion when resonance occurs, which will destroy the cross elastic anti-vibration and anti-damage device. If the base stiffness of the springs 6, 8, 12, 13 is too high, the tension or pressure of the springs 6, 8, 12, 13 on the blade to be twisted will be small, and the twisting amplitude of the wind turbine will be large. Finding the appropriate value of the base stiffness of the springs 6, 8, 12, 13 is therefore of exceptional importance for the present invention.

The wind turbine blade with or without the cross elastic vibration-resistant and damage-resistant device is staticThe modal analysis is carried out under the conditions of the rated working running speed of 1.266rad/s and different spring base stiffness selection. Since the first three orders concentrate the main energy of the vibration, the modal frequency of the first three orders can be regarded as the natural frequency of the wind turbine blade. Fig. 4 and 5 show a comparison line graph of the modal frequency and the maximum deformation of the front three orders under different spring stiffnesses of the wind turbine in a static state and without the cross anti-vibration and anti-damage device, and a comparison line graph of the modal frequency and the maximum deformation of the front three orders under different spring stiffnesses of the wind turbine in a rated working state and without the cross anti-vibration and anti-damage device, respectively. Through modal analysis calculation, the base stiffness of the spring is lower than 1500N/m³At resonance, the spring will experience lateral torsional failure. When the base stiffness of the spring is higher than 20000N/m³At the moment, the wind turbine has overlarge twisting amplitude. Therefore, the device is suitable for the spring foundation with the rigidity of 1500N/m³--20000N/m³In the meantime. Through (a), (b) and (c) of fig. 4 and (a), (b) and (c) of fig. 5, the front third-order modal frequency of the wind turbine without the cross anti-vibration and anti-damage device is about 0.6HZ when the wind turbine rotates and is at rest, and the front third-order modal frequency of the wind turbine without the cross anti-vibration and anti-damage device is about 2.5 to 2.7HZ when the wind turbine rotates and is at rest under different basic rigidities. Therefore, when the cross-shaped vibration and damage resisting device is not additionally arranged, the natural frequency of the wind turbine is about 0.6HZ, and after the cross-shaped elastic vibration and damage resisting device is additionally arranged, the natural frequency of the wind turbine is changed into 2.5-2.7HZ under different basic rigidities, so that the natural frequency is improved by about 77%. Meanwhile, the modal frequency of the front third order of the wind turbine is increased along with the increase of the basic rigidity, and the increase amplitude is small. The maximum deformation of the stationary wind turbine blade at the time of resonance is found to be reduced by about 26% -40% by fig. 4 (d) and fig. 5 (d). The maximum deformation of the wind turbine blade is reduced by about 20-40% during rated operation. The possibility of great damage of the wind turbine blade due to resonance is reduced, and the service life of the wind turbine is prolonged.

In addition, because the application range of the base stiffness of the spring is wide, the spring is 10000N/m³And the same conclusion is obtained under the condition of analyzing the basic rigidity and other applicable basic rigidity. FIG. 6 shows the spring at 10000N/m³FoundationAnd comparing the maximum deformation of the wind turbine with the maximum deformation of the wind turbine without the cross vibration-resistant and damage-resistant device under the static or rated working state of the wind turbine under the rigidity with a scatter diagram. Compared with the situation that the cross-shaped anti-vibration and anti-damage device is not additionally arranged, the maximum deformation of the blade moves from the blade tip position to the middle part of the blade when the blade resonates, so that the fragile blade tip part is protected when the blade resonates, and the service life of the wind turbine is prolonged.

The above description is only for the preferred embodiment of the present invention, and the present invention is not limited to the above embodiments, and the scope of the present invention is not limited thereby, it is understood that other modifications and variations directly derived or suggested by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the scope of the present invention.