A multi-structure combined blade noise reduction serrated trailing edge and installation method

Abstract

The present invention discloses a blade noise reduction serrated trailing edge with a multi-structure combination and an installation method, comprising a blade and a trailing edge, wherein the trailing edge comprises a plurality of groups of different serrated structures, the serrated structures being arranged continuously in a certain number, and the plurality of groups of serrated structures being continuously and equidistantly installed at the lower end edge of the blade, and the spliced ​​length of the serrated structures being 1 / 3 of the total length of the blade. The present application can adjust the serration size accordingly according to the airfoil changes of different blades, so that the serrated trailing edge applied to the blade can give full play to its noise reduction ability, thereby greatly improving the practicality of the present application.

Description

Technical Field

[0001] The present invention relates to blade aerodynamic noise reduction, and more particularly to a blade noise reduction serrated trailing edge with a multi-structure combination and an installation method thereof. Background Art

[0002] With the expansion of industry and the improvement of people's quality of life, the urgent demand for energy has made clean energy a major direction for future energy development. Wind energy, as a clean and renewable energy source, is abundant and widely distributed, attracting the attention of energy industries worldwide. Widespread use of wind energy can effectively reduce dependence on fossil fuels in production and daily life, significantly improving environmental quality. As wind power technology continues to mature, the size of wind turbines is also increasing. Their key features are longer blades and taller towers, which capture more wind energy resources. The increase in wind turbine size has brought certain benefits to local wind farms and effectively reduced the environmental pollution caused by fossil fuels. However, the aerodynamic noise generated by wind turbines during operation can cause problems such as disharmony between wind power and the natural environment and residents' activities. Therefore, noise reduction technology modifications for wind turbines in low-wind-speed areas can prevent noise pollution caused by wind power development, playing a vital role in protecting the ecological environment and ensuring the healthy and sustainable development of the wind power industry.

[0003] At present, an important method to reduce the aerodynamic noise generated during the operation of wind turbines is to apply a serrated structure to the trailing edge of the blade, which reduces the far-field aerodynamic noise of the wind turbine in the low-frequency band to a certain extent. However, the disadvantage of the above method is that the serrated trailing edge applied to the blade cannot adjust the serration size accordingly according to the changes in the blade's airfoil, resulting in the serrated trailing edge applied to the blade being unable to fully exert its noise reduction ability.

[0004] Chinese patent CN110242494A discloses a movable serrated trailing edge structure for a wind turbine with a flap function. By adding a deflection control system to a conventional noise-reducing trailing edge, it can achieve the functions of lift increase, noise reduction, and assisted shutdown for different operating states of the wind turbine. However, the serrated trailing edges of this application are all of the same size. Because the airfoil shape changes with the span direction of the blade, the noise reduction effect of a fixed serrated trailing edge is not as good as that of a multiple, variable serrated trailing edge. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to change the serration size according to the airfoil of the blade to prevent noise.

[0006] The present invention solves the above-mentioned technical problems through the following technical means: a blade noise reduction serrated trailing edge with a multi-structure combination, comprising a blade and a trailing edge, wherein the trailing edge comprises multiple groups of different serrated structures, the serrated structures are arranged continuously in a certain number, and multiple groups of the serrated structures are equidistantly and continuously installed at the lower end edge of the blade, and the spliced ​​length of the serrated structures is 1 / 3 of the total length of the blade.

[0007] The present application selects the height of the serration structure according to the blades of different thicknesses, determines the width of the serration structure according to the height of the serration structure, and then installs multiple groups of serration structures in sequence and equidistantly at the lower end of the blade, thereby achieving the purpose of noise prevention by changing the serration size according to the airfoil of the blade.

[0008] Preferably, the blade includes a suction surface, and the plurality of groups of serration structures are sequentially bonded to the horizontal plane of the suction surface, and are all installed horizontally in the direction of the airfoil chord length.

[0009] Preferably: multiple groups of the sawtooth structures are all "polygonal" structures, the lower ends of the sawtooth structures are all "rectangular" structures, the lower ends of the sawtooth structures are provided with a transition zone and a bonding zone from top to bottom, and one end of the bonding zone is in contact with the horizontal plane of the suction surface.

[0010] Advantages: Ensures the stability of the sawtooth structure installation.

[0011] Preferably, the upper ends of the sawtooth structures are transition zones, and the top ends of the transition zones are "arc-shaped" structures.

[0012] Advantages: The setting of the "arc-shaped" structure ensures the noise reduction performance of the sawtooth structure.

[0013] Preferably, the transition zones of each group of the sawtooth structures have a vertical line as the highest point and transition to the left and right sides in the form of circular arcs.

[0014] Advantages: Reduces the aerodynamic noise generated during the operation of wind turbines.

[0015] Preferably, the sawtooth structures are made of Si-PC / ASA plastic alloy material.

[0016] Advantages: impact resistance and high heat resistance.

[0017] Preferably, the sawtooth structure includes a first sawtooth, a second sawtooth, a third sawtooth, and a fourth sawtooth. The first sawtooth, the second sawtooth, the third sawtooth, and the fourth sawtooth are each provided in multiple groups, and each group is provided with multiple sawtooth structures.

[0018] Preferably, there is a certain distance between one of the outermost first serrations and the root of the blade.

[0019] Preferably, the ratio of the height of each group of sawtooth structures to the thickness of the blade is 10, and the height-to-width ratio of each group of sawtooth structures is between 0.25-2.

[0020] Advantages: Improves the practicality of this application.

[0021] According to the above-mentioned method for installing a blade noise reduction serrated trailing edge with a multi-structure combination, the method includes the following steps: measuring the thickness of the blade, selecting the height of the serrated structure according to the thickness of the blade, determining the width of the serrated structure according to the height of the serrated structure, and installing multiple groups of the serrated structures in sequence and equidistantly at the lower end edge of the blade, splicing them into the trailing edge, and the length of the trailing edge is equal to 1 / 3 of the total length of the blade.

[0022] The advantages of the present invention are that: by measuring the thickness of the blade, the height of the serration structure is selected according to the thickness of the blade, and the width of the serration structure is determined by the height of the serration structure, multiple groups of the serration structures are sequentially and equidistantly installed at the lower edge of the blade, so that the serration size can be adjusted accordingly according to the change of the blade airfoil, thereby effectively improving the practicality of the present invention;

[0023] The present application effectively reduces the far-field aerodynamic noise of the fan in the low-frequency band by setting the sawtooth structure to a "polygonal" structure, the lower end of the sawtooth structure to a "rectangular" structure, the upper end of the sawtooth structure to a transition zone, and the top of the transition zone to a "circular arc" structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the overall structure of a blade noise reduction serrated trailing edge with a multi-structure combination according to an embodiment of the present invention;

[0025] Figure 2 This is a vertical schematic diagram of the overall structure of a blade noise reduction serrated trailing edge with a multi-structure combination according to an embodiment of the present invention;

[0026] Figure 3 For the embodiment of the present invention Figure 2 A schematic diagram of the enlarged structure of part A;

[0027] Figure 4 This is a schematic diagram of the partial structure of a blade noise reduction serrated trailing edge with a multi-structure combination according to an embodiment of the present invention;

[0028] Figure 5 A schematic side view of a serrated structure of a blade noise reduction serrated trailing edge with a multi-structure combination according to an embodiment of the present invention;

[0029] Figure 6 For the embodiment of the present invention Figure 5 Schematic diagram of the enlarged structure of part B.

[0030] In the figure: 1-blade; 11-suction surface; 2-trailing edge; 21-serration structure; 211-first serration; 212-second serration; 213-third serration; 214-fourth serration; 22-bonding area; 23-transition area; 24-triangle area. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] See Figure 1 This embodiment discloses a blade noise reduction serrated trailing edge with a multi-structure combination, including a blade 1 and a trailing edge 2.

[0033] See also Figure 1-3 The blade 1 is of the prior art, and includes a suction surface 11 , with the trailing edge 2 spliced ​​at the lower edge of the suction surface 11 .

[0034] In this embodiment, considering the actual noise reduction effect, the ratio of the sawtooth height h to the wind turbine trailing edge thickness δ is designed to be 10, and the ratio of the sawtooth height h to the sawtooth width λ is designed to be 2.

[0035] The trailing edge 2 includes multiple groups of different serration structures 21. The multiple groups of serration structures 21 are arranged continuously in a certain number, are sequentially bonded to the horizontal surface of the suction surface 11, and are installed horizontally in the direction of the airfoil chord length.

[0036] In this embodiment, the length of the serration structure 21 is 1 / 3 of the total length of the blade 1 .

[0037] See Figure 1 The sawtooth structure 21 includes a first sawtooth 211 , a second sawtooth 212 , a third sawtooth 213 , and a fourth sawtooth 214 , and each of the sawtooth structures 21 is provided in multiple groups, and each group is provided with multiple sawtooths.

[0038] In this embodiment, there are 13 groups of first serrations 211 , and each group has 6 serrations. The width of the first serrations 211 is 40 mm, totaling 3120 mm. There is a certain distance between one of the outermost first serrations 211 and the root of the blade 1 .

[0039] In this embodiment, the second saw teeth 212 are provided in 20 groups, each group is provided with 5 saw teeth, the width of the second saw teeth 212 is 50 mm, and the total width is 5000 mm. The second saw teeth 212 are connected to the first saw teeth 211 in sequence.

[0040] In this embodiment, the third saw teeth 213 are provided in 20 groups, each group is provided with 5 saw teeth, the width of the third saw teeth 213 is 60 mm, and the total width is 6000 mm. The third saw teeth 213 are connected to the second saw teeth 212 in sequence.

[0041] In this embodiment, the fourth saw teeth 214 are provided in 18 groups, each group is provided with 4 saw teeth, the width of the fourth saw teeth 214 is 80 mm, a total of 5760 mm, and the fourth saw teeth 214 are connected to the third saw teeth 213 in sequence.

[0042] Sawtooth structure installation starting position and size details

[0043]

[0044] Referring to 4-6 at the same time, the serrated structures 21 are all "polygonal" structures, and the lower ends of the serrated structures 21 are all "rectangular" structures. The lower ends of the serrated structures 21 are provided with a transition area 23 and a bonding area 22 from top to bottom, and one end of 22 is in contact with the horizontal plane of the suction surface 11.

[0045] The upper ends of the sawtooth structures 21 are all set as transition zones 24, and the top ends of the transition zones 24 are all "arc-shaped" structures, which effectively reduce the far-field aerodynamic noise of the fan in the low-frequency band.

[0046] In this embodiment, the transition areas 24 and 23 of each set of sawtooth structures 21 have their vertical lines as the highest points and transition to the left and right sides in circular arcs, thereby effectively reducing the aerodynamic noise generated during the operation of the wind turbine.

[0047] In this embodiment, the sawtooth structures 21 are made of Si-PC / ASA plastic alloy material, which has impact resistance and high heat resistance.

[0048] The working principle of this embodiment is: the staff first measures the thickness of the blade 1, selects the height of the serration structure 21 according to the thickness of the blade 1, and then determines the width of the serration structure 21 according to the height of the serration structure 21, and installs multiple groups of serration structures 21 in sequence and equidistantly at the lower edge of the blade 1. This application can adjust the serration size accordingly according to the airfoil changes of different blades, so that the serration trailing edge applied to the blade can give full play to its noise reduction ability, greatly improving the practicality of this application.

[0049] Comparative Example:

[0050] The noise reduction effect of the serrated trailing edge designed in this project was tested, and the operating noise of the wind turbine was compared under the same wind speed. The sound level meter was monitored and measured 1.2 meters above the ground, and the data was read 150 meters behind the wind turbine. The dynamic response of the sound level meter was set to the "slow" gear.

[0051] A-weighted sound pressure level monitoring results before and after the renovation

[0052]

[0053] By applying a serrated trailing edge to the blades of a 2MW wind turbine, taking an incoming wind speed of 8m / s as an example, the wind turbine has a noise reduction effect of 3.7dB. While ensuring that the output power remains unchanged, the noise reduction effect is significant.

[0054] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A blade noise reduction serrated trailing edge with multiple structural combinations, characterized in that: The invention comprises a blade (1) and a trailing edge (2), wherein the trailing edge (2) comprises a plurality of different sawtooth structures (21), wherein the sawtooth structures (21) are arranged continuously in a certain number, and the plurality of sawtooth structures (21) are continuously installed at the lower edge of the blade (1) at equal intervals, and the length of the spliced ​​sawtooth structures (21) is 1 / 3 of the total length of the blade (1); The sawtooth structure (21) comprises a first sawtooth (211), a second sawtooth (212), a third sawtooth (213), and a fourth sawtooth (214); the first sawtooth (211), the second sawtooth (212), the third sawtooth (213), and the fourth sawtooth (214) are provided in multiple groups, and each group is provided with multiple sawtooth structures (21); The ratio of the height of each set of sawtooth structures (21) to the thickness of the blade (1) is 10, and the height-to-width ratio of each set of sawtooth structures (21) is between 0.25 and 2; The upper ends of the sawtooth structures (21) are all transition areas (23), and the tops of the transition areas (23) are all "arc-shaped" structures; the transition areas (23) and transition areas (23) of each set of sawtooth structures (21) are all at the highest point with the vertical line therein as the highest point, and transition to the left and right sides in an arc shape; The blade (1) includes a suction surface (11), and a plurality of groups of sawtooth structures (21) are sequentially bonded to the horizontal surface of the suction surface (11) and are all installed horizontally in the direction of the airfoil chord length; The sawtooth structures (21) are all made of Si-PC / ASA plastic alloy material.

2. The multi-structure combined blade noise reduction serrated trailing edge according to claim 1, characterized in that: The plurality of groups of sawtooth structures (21) are all polygonal structures, the lower ends of the sawtooth structures (21) are all rectangular structures, and the lower ends of the sawtooth structures (21) are provided with a transition area (23) and a bonding area (22) from top to bottom, and one end of the bonding area (22) is in contact with the horizontal plane of the suction surface (11).

3. The multi-structure combined blade noise reduction serrated trailing edge according to claim 1, characterized in that: There is a certain distance between one of the outermost first serrations (211) and the root of the blade (1).

4. A method for installing a blade noise reduction serrated trailing edge with multiple structural combinations according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: measuring the thickness of a blade (1), selecting the height of a sawtooth structure (21) according to the thickness of the blade (1), determining the width of the sawtooth structure (21) according to the height of the sawtooth structure (21), and sequentially and equidistantly installing a plurality of sets of the sawtooth structures (21) at the lower end edge of the blade (1) to form the trailing edge (2), wherein the length of the trailing edge (2) is equal to 1 / 3 of the total length of the blade (1).

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