A wind turbine blade vortex-induced vibration flexible suppression device

Abstract

The application provides a wind power blade vortex-induced vibration flexible suppression device, which is composed of a flexible cylinder, a base, an elastic collection net, fastening ropes and positioning ropes, and is characterized in that: the flexible cylinder is fastened and installed on the base through the base, the base is arranged on the front and back sides of the elastic collection net at a certain interval, a plurality of fastening ropes are arranged on the elastic collection net in an end-to-end and interval arrangement mode along the span direction, the fastening ropes on the elastic collection net pass through the annular holes below the base, the base is bound on the elastic collection net, and the positioning ropes at the lower part of the elastic collection net are aligned with the trailing edge of the blade, so that the elastic collection net is wrapped at the blade tip. The blade vortex-induced vibration flexible suppression device provided by the application can self-adaptively destroy the vortex shedding mechanism of airflow, effectively realize the vortex-induced vibration suppression of the blade, has a simple structure and is convenient to process, the technical route is reliable, installation and disassembly are simple, and the blade surface is not affected during installation and disassembly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind power equipment, and particularly relates to a vortex-induced vibration flexible suppression device for wind power blades. BACKGROUND

[0002] In recent years, renewable energy development in China has entered a new stage. Wind power clean energy can effectively control the destruction of surface vegetation, maximize the protection of the ecological environment, and can provide people with power energy while reducing carbon emissions. It has become an inevitable choice in the implementation of sustainable energy strategy. The newly added capacity of wind power in China has doubled for many years, and China has become the country with the largest installed capacity of wind power in the world. The development of wind power has achieved remarkable results.

[0003] With the continuous development of wind power technology, large wind turbines are becoming more common. However, the wind turbine blades are getting longer, which increases the sensitivity of the structure to the wind. When the wind turbine blades are in a stationary state, the random incoming wind direction may cause the blades to be in a high angle of attack and a complex flow field. Under a certain wind speed and attack angle, the airflow flowing through the blade will produce periodic vortex shedding, which will produce periodic forces on the blade due to vortex shedding, thereby exciting the blade to vibrate vertically and in the same direction as the wind direction. When the difference between the vortex shedding frequency and the oscillation frequency is small enough, it will be completely synchronized, and the blade will vibrate greatly, that is, vortex-induced vibration. Safety risks and safety incidents caused by vortex-induced vibration during wind turbine blade transportation and wind turbine parking are often seen in the media, becoming a difficult problem faced by on-site producers and managers.

[0004] Because the continuous flow of fluid medium in the air leads to the inevitability of vortex-induced vibration, it is necessary to consider and explore the direction of reducing the influence of vortex-induced vibration on the safety of wind turbines as much as possible in the engineering application design and use stage. Therefore, it is necessary to propose a vortex-induced vibration suppression device installed at the tip of the blade. SUMMARY

[0005] The present application proposes a vortex-induced vibration flexible suppression device for wind power blades to effectively suppress the occurrence of vortex-induced vibration during wind power blade transportation and installation.

[0006] To achieve the above technical purposes, the technical scheme adopted by the present application is as follows:

[0007] The wind power blade vortex-induced vibration flexible suppression device comprises a base and a flexible column, the flexible column is fixedly installed on the base, the base is fixedly installed at a blade tip of the wind power blade through a connecting piece, when the blade tip of the wind power blade is blown by airflow, the flexible column can be deformed under the action of the airflow and periodically vibrate to disturb the original vortex generation and shedding frequency of the airflow.

[0008] To optimize the above technical solution, the specific measures taken also include:

[0009] The connecting piece comprises an elastic collection net and a fastening rope, the elastic collection net is wrapped at the blade tip of the wind power blade, the fastening rope is an elastic rope that can be collected, a plurality of fastening ropes are arranged on the elastic collection net in the spanwise direction, the middle part of the fastening rope is fixed on the net body, and the two ends are free ends, the fastening rope can fix the elastic collection net on the wind power blade when the free ends are collected, a plurality of ring holes are arranged on the base, and the fastening rope passes through the ring holes to fix the base on the elastic collection net.

[0010] The number of the base is several, and the base is distributed on the front side and the rear side of the blade tip of the wind power blade.

[0011] A plurality of flexible columns are arranged on each base, and gaps are arranged between the flexible columns, so that the flexible columns do not interfere with each other when deformed under the action of the airflow.

[0012] The elastic collection net is provided with a positioning rope, and the positioning rope is used to indicate the positional relationship between the elastic collection net and the wind power blade when the elastic collection net is installed on the wind power blade.

[0013] The thickness of the base is 0.5 cm, the spanwise dimension of the base is not more than 5% of L, and the chordwise dimension of the base is 20% of the spanwise dimension, and L is the length of the blade.

[0014] The bases are arranged at equal intervals in the spanwise direction of the blade, and the spanwise interval between adjacent bases is not more than half of the spanwise length of the base.

[0015] The flexible column is a variable cross-section cylinder made of flexible material, and the diameter of the bottom of the cylinder is about 1.5 to 2 times the diameter of the top of the cylinder.

[0016] The length of the elastic collection net is 20% to 40% of L.

[0017] The elastic collection net is made of polyurethane fiber material.

[0018] The present application has the following advantages:

[0019] 1、When the elastic collection net is wrapped on the blade, the flexible column on the base plays a major role in disturbing the airflow. When there is no wind, the flexible column remains in a natural state. When the airflow blows, the top of the flexible column will be deformed under the action of the airflow and will produce periodic vibration that adapts to the frequency of the airflow. When multiple rows of flexible columns on multiple bases vibrate, the self-adapting vibration will disturb the original vortex generation and shedding frequency of the airflow, destroy the original vortex shedding mechanism at the blade tip, thereby inhibiting the vortex shedding on the leeward side of the blade and the generation of vortex-induced vibration at the blade tip, reducing the harm caused by vortex-induced vibration and ensuring the safety of the blade during transportation and hoisting.

[0020] 2、When installing, the present application only needs to align the positioning rope with the trailing edge of the blade, then wrap the elastic collection net on the surface of the blade, and then tighten the fastening rope to complete the installation. When disassembling, loosen the fastening rope and pull down the elastic collection net to complete the disassembly. Since the elastic collection net uses elastic material with excellent elasticity, it will be firmly attached to the surface of the blade in cooperation with the use of the fastening rope. The technical route of the present application is clear, the cost is low, the installation and disassembly are convenient, it can be reused, and it is beneficial to large-area popularization and use. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of the vortex-induced vibration suppression device installation;

[0022] Figure 2 is a schematic diagram of the vortex-induced vibration suppression device;

[0023] Figure 3 is a schematic diagram of the base and flexible column;

[0024] Figure 4 is a schematic diagram of the base bottom ring hole;

[0025] Figure 5 is a schematic diagram of the elastic collection net.

[0026] Marked name in the figure: 1, elastic collection net; 2, fastening rope; 3, base; 4, flexible column; 5, ring hole; 6, positioning rope. DETAILED DESCRIPTION

[0027] The embodiments of the present application will be further described in detail below in combination with the drawings.

[0028] As shown in Figures 1 to 5 , the present application provides a vortex-induced vibration flexible suppression device for wind power blades, which comprises an elastic collection net 1, a fastening rope 2, a base 3, a flexible column 4, a ring hole 5, and a positioning rope 6.

[0029] As shown in Figure 1 , the length of the blade is L, and the blade span is Figure 1The left-right direction of the paper is the chordwise direction of the blade Figure 1 The up-down direction of the paper is the spanwise direction of the blade Figure 1 The upper side of the middle blade, the vortex-induced vibration suppression device is installed at the blade tip, and the installation area length is 20%-40%L.

[0030] As shown in Figure 2 and Figure 5 , the elastic collection net 1 includes a net body, a fastening rope 2, and a positioning rope 6. The fastening rope 2 is arranged on the net body in the spanwise direction, and the opening on the left side of the net body is collected by the fastening rope 2. The net body is made of a material with certain strength and elasticity (such as polyurethane fiber material), has good tightness and durability, and the mesh shape of the net body can be rectangular, diamond, etc. The mesh count (the number of mesh per square inch) of the net body is subject to the installation conditions.

[0031] The shape of the net body is close to the shape of the blade at the tip, and a positioning rope 6 is arranged on the lower side of the net body. The positioning rope is obviously different from the shape of the net body, which is convenient for visual differentiation during installation. The positioning rope 6 is aligned with the trailing edge of the blade when the elastic collection net 1 is wrapped around the blade.

[0032] The fastening rope 2 is an elastic rope that can be collected. A plurality of fastening ropes 2 are arranged on the net body in the spanwise direction. The middle part of the fastening rope 2 is fixed on the net body, and the two ends are free ends used to collect the net body and fix the net body on the blade.

[0033] The elastic collection net 1 is wrapped around the tip. After the elastic collection net 1 is wrapped around the blade, due to the tightness of the net body material, the net body will be tightly attached to the surface of the blade. At this time, the fastening rope 2 arranged on the net body is tightened to prevent the net body from deflecting.

[0034] As shown in Figure 2 , the pedestals 3 at the same spanwise position are considered as the same column.

[0035] As shown in Figure 3 and Figure 4 , the pedestal 3 is a long rectangular thin plate. The thickness of the pedestal 3 is about 0.5 cm. The spanwise size of the pedestal 3 is not more than 5%L. The chordwise size of the pedestal 3 is about 20% of the spanwise size. The chordwise interval of adjacent pedestals 3 is determined according to the chord length of the blade at that position. Because the chord length of the blade at the tip is small, and the chord length of the blade in the middle is large, for example, three pedestals 3 are arranged along the chordwise direction of the blade at the tip, and five pedestals 3 are arranged along the chordwise direction of the blade in the middle. The interval between two adjacent columns of pedestals 3 is not more than half of the spanwise length of the pedestal 3.

[0036] The pedestals 3 are arranged on the front and back sides of the elastic collection net 1. When the airflow flows through the blade from various directions, the flexible spoiler devices arranged on the pedestals 3 can effectively play a role.

[0037] The flexible column 4 is a variable cross-section cylinder made of a material with good flexibility. The flexible material allows the upper part of the flexible column to deform in the flow field. The height of the flexible column 4 is 2-4 cm, the bottom diameter is 1.5-2 times the top diameter, and the diameter of the cylinder uniformly transitions from the bottom to the top. At this time, the upper end of the smaller diameter cylinder is more likely to swing under the action of the airflow, thereby allowing the flexible column 4 to form a flexible structure similar to a reed that can reciprocate after being blown by the wind. At the same time, the thickened bottom of the flexible column 4 can avoid the deformation range of the flexible column 4 being too large (such as deformation from the bottom of the cylinder) when the airflow flows through the flexible column 4, which can cause the flexible columns 4 to interfere with each other.

[0038] As shown in Figure 3 To ensure that the flexible columns 4 do not interfere with each other when deformed by the incoming flow, the installation method shown in the figure is adopted: the flexible columns 4 are installed on the spoiler, and the adjacent flexible columns 4 on the same base 3 have the same spacing, i.e., the flexible columns 4 in the same row have the same spacing, and the flexible columns 4 in different rows also have the same spacing, and the flexible columns 4 in different rows are installed in the manner of inserting gaps. The number of flexible columns 4 arranged on a single base 3 and the spacing distance depend on the height of the flexible column 4 and the size of the base.

[0039] As shown in Figure 4 The base 3 is provided with a plurality of pairs of small ring holes 5 at the bottom, and the fastening ropes 2 arranged in the spanwise direction on the elastic containment net 1 can pass through the ring holes 5, so that the base 3 is tightly attached to the surface of the elastic containment net 1.

[0040] The blade vortex-induced vibration flexible suppression device proposed in the embodiment has a simple structure, is easy to process, has a reliable technical route, is easy to install and disassemble, and does not affect the surface of the blade during installation and disassembly. After the elastic containment net is wrapped around the surface of the blade, the fastening ropes are tightened to complete the installation, and after the installation is completed, the vortex shedding mechanism near the blade can be effectively destroyed by the flexible columns on the base, thereby achieving the suppression of the vortex-induced vibration of the blade.

[0041] The above is only a preferred embodiment of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical solution that falls within the scope of the present application should be considered within the protection scope of the present application. It should be noted that for ordinary technical personnel in the technical field, some improvements and refinements without departing from the principles of the present application should be considered within the protection scope of the present application.

Claims

1. A flexible device for suppressing vortex-induced vibration of wind turbine blades, characterized by: The invention comprises a base (3) and a flexible column (4), wherein the flexible column (4) is fixedly mounted on the base (3), and the base (3) is fixedly mounted at the tip of a wind turbine blade via a connecting piece, and the length of the mounting area is 20%-40% L; when air flows through the tip of the wind turbine blade, the flexible column (4) can be deformed under the action of the air flow and generate periodic vibrations to adapt to the frequency of the air flow, thereby disrupting the original vortex generation and shedding frequency of the air flow; the flexible column (4) is a variable-section cylinder made of a flexible material, and the diameter of the cylinder bottom is 1.5 to 2 times the diameter of the cylinder top; The number of the bases (3) is several and they are distributed on the front side and the rear side of the tip of the wind turbine blade; A plurality of flexible columns (4) are provided on each base (3), and gaps are provided between the flexible columns (4). The gaps prevent the flexible columns (4) from interfering with each other when deformed by airflow. The spanwise dimension of the base (3) does not exceed 5% L, the chordwise dimension of the base (3) is 20% of the spanwise dimension, and L is the blade length.

2. The flexible suppression device for vortex-induced vibration of wind turbine blades according to claim 1 is characterized by: The connecting member comprises an elastic converging net (1) and a fastening rope (2); the elastic converging net (1) is wrapped around the tip of the wind turbine blade; the fastening rope (2) is a contractible elastic rope; a plurality of fastening ropes (2) are arranged in sequence along the span direction on the elastic converging net (1); the middle portion of the fastening rope (2) is fixed to the net body; the two ends are free ends; when the free ends are contracted, the fastening rope (2) can fix the elastic converging net (1) to the wind turbine blade; a plurality of ring holes (5) are provided on the base (3); the fastening rope (2) passes through the ring holes (5) to fix the base (3) to the elastic converging net (1).

3. The flexible suppression device for vortex-induced vibration of wind turbine blades according to claim 2 is characterized by: The elastic converging net (1) is provided with a positioning rope (6), and the positioning rope (6) is used to indicate the positional relationship between the elastic converging net (1) and the wind turbine blade when the elastic converging net (1) is installed on the wind turbine blade.

4. The flexible suppression device for vortex-induced vibration of wind turbine blades according to claim 1 is characterized by: The base (3) has a thickness of 0.5 cm.

5. The flexible suppression device for vortex-induced vibration of wind turbine blades according to claim 1 is characterized by: The bases (3) are arranged at equal intervals along the span direction of the blade, and the span-wise interval between adjacent bases (3) does not exceed half of the span-wise length of the base 3.

6. The flexible suppression device for vortex-induced vibration of wind turbine blades according to claim 2 is characterized by: The length of the elastic gathering net (1) is 20%-40% L.

7. The flexible suppression device for vortex-induced vibration of wind turbine blades according to claim 2 is characterized by: The elastic gathering net (1) is made of polyurethane fiber material.

Images