Wind turbine generator vibration isolation structure based on adjustable acoustic metamaterial and application

Abstract

The invention discloses a wind turbine generator vibration isolation structure based on an adjustable acoustic metamaterial and application. The wind turbine generator vibration isolation structure comprises a substrate, an elastic element and a tunable mass element. The substrate is made of a metal material; the elastic element is arranged on the substrate and is made of a non-metal material; and the tunable mass element is arranged on the elastic element and is made of a metal material. Compared with a traditional vibration isolator, the wind turbine generator vibration isolation structure based on the adjustable acoustic metamaterial can respond to vibration within a wide frequency range, vibration suppression of the corresponding frequency is achieved, the structure not only responds to vibration under a certain specific frequency, and even if the vibration is relatively complex, the vibration suppression effect is good. And a good vibration reduction effect can also be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a wind turbine vibration isolation structure based on adjustable acoustic metamaterials and its application. Background Art

[0002] With the intensification of global energy demand and greenhouse effect, the world's demand for clean energy is also growing. Wind power generation, as the main clean energy, has developed rapidly in recent years. With the continuous increase in the power of wind turbines, more and more wind turbines above 10 megawatts are put into use, and the operation of various equipment inside the unit is increasingly affected by vibration factors.

[0003] Among them, electrical equipment such as the main control cabinet is more likely to be overlooked in terms of the influence of vibration factors. Although key electrical equipment such as the control cabinet will be subjected to durability vibration response tests in accordance with relevant standards before it is officially put into operation and work, and the gearbox and generator in the cabin are supported by elastic support isolators, the vibration on the gearbox and generator can be better transmitted to the main frame through elastic support, which plays a certain vibration isolation role. However, since the location of important equipment such as the control cabinet is close to the gearbox and generator, and the unit is affected by the combined influence of blade and tower vibration in addition to the vibration on the transmission chain during operation, the control cabinet door and cabinet body will be damaged and the internal precision components will still fail due to the influence of vibration factors. In addition, the traditional vibration reduction structure can only respond to vibrations at a certain frequency, resulting in limitations in its vibration reduction effect.

[0004] Therefore, how to achieve overall vibration reduction of the unit equipment while ensuring that the original structure of the control cabinet remains unchanged, and how to improve the frequency range of vibration response are issues that need to be urgently addressed. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes a wind turbine vibration isolation structure and application based on adjustable acoustic metamaterials, which can respond to vibrations within a wider frequency range and achieve overall vibration reduction of the unit equipment.

[0006] In order to achieve the above-mentioned object, the present invention is implemented through the following technical solutions: a wind turbine vibration isolation structure based on adjustable acoustic metamaterials, comprising a substrate, an elastic element and a tunable mass element;

[0007] The substrate is made of metal material;

[0008] The elastic element is arranged on the substrate and is made of non-metallic material;

[0009] The tunable mass element is arranged on the elastic element and is made of metal material.

[0010] Furthermore, the substrate is made of aluminum metal material.

[0011] Furthermore, the elastic element is made of silicone rubber non-metallic material.

[0012] Furthermore, the tunable mass element is made of steel metal material.

[0013] Furthermore, the plurality of substrates are arranged in an array in sequence, and adjacent substrates are fixedly connected.

[0014] Further, the substrate is rectangular, has a lattice constant of 30 mm, and a thickness of 3 mm;

[0015] The elastic element and the tunable mass element are both cylindrical, with a radius of 12 mm and a thickness of 2.5 mm-4.5 mm.

[0016] Furthermore, elastic elements and tunable mass elements are provided on both sides of the substrate.

[0017] The beneficial effect of the above-mentioned wind turbine vibration isolation structure based on adjustable acoustic metamaterials is that compared with traditional vibration isolators, this structure can respond to vibrations within a wider frequency range and achieve vibration suppression of corresponding frequencies, rather than just responding to vibrations at a specific frequency. Even if the vibration is relatively complex, it can still play a good vibration reduction role.

[0018] An application of a wind turbine vibration isolation structure adopts the above-mentioned wind turbine vibration isolation structure based on adjustable acoustic metamaterial, and the structure is fixedly installed on a supporting steel frame, and is fixedly connected to the unit equipment through the supporting steel frame.

[0019] Furthermore, when the substrate is subjected to external force, the tunable mass element applies internal force to the substrate in the opposite direction, causing the substrate to vibrate reciprocatingly. When the frequency of the external force falls into the frequency band gap of the structure, the structure can localize the external force, preventing the vibration energy from continuing to propagate.

[0020] Furthermore, the starting frequency of the frequency band gap is ω1, the cutoff frequency is ω2, the mass of the substrate is m2, the mass of the tunable mass element is m1, the equivalent stiffness of the elastic element is k, and the starting frequency and cutoff frequency of the frequency band gap are expressed as follows:

[0021]

[0022]

[0023] The beneficial effect of the application of the above-mentioned wind turbine vibration isolation structure is that by installing a vibration reduction structure on the unit equipment, the overall vibration reduction of the equipment can be achieved without changing the original structure, reducing structural damage and failure of precision components of electrical equipment such as control cabinets due to vibration, thereby reducing the equipment failure rate, improving the equipment's operating reliability, and reducing on-site repair and maintenance rates and operation and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation of the present invention, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0025] Figure 1 A front view of a unit cell structure of a wind turbine vibration isolation structure based on an adjustable acoustic metamaterial provided in one embodiment of the present invention;

[0026] Figure 2 An acoustic metamaterial vibration reduction structure of a wind turbine vibration isolation structure based on an adjustable acoustic metamaterial is provided in one embodiment of the present invention;

[0027] Figure 3 A vibration reduction calculation result 1 of a wind turbine vibration isolation structure based on an adjustable acoustic metamaterial provided by an embodiment of the present invention;

[0028] Figure 4 A second vibration reduction calculation result of a wind turbine vibration isolation structure based on an adjustable acoustic metamaterial provided in an embodiment of the present invention;

[0029] Figure 5 A schematic diagram of an application of a wind turbine vibration isolation structure provided by an embodiment of the present invention;

[0030] Figure 6 for Figure 1 Schematic diagram of the starting frequency mode of the unit cell structure shown;

[0031] Figure 7 for Figure 1 Schematic diagram of the cutoff frequency mode of the unit cell structure shown;

[0032] Figure 8 for Figure 1 Schematic diagram of the vibration reduction equivalent model of the unit cell structure shown;

[0033] Reference numerals:

[0034] 1- Unit equipment;

[0035] 2-Supporting steel frame;

[0036] 3-acoustic metamaterial vibration reduction structure, 30-substrate, 31-elastic element, 32-tunable mass element. DETAILED DESCRIPTION

[0037] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0038] See also Figure 1 and Figure 2 The present invention provides a wind turbine vibration isolation structure based on an adjustable acoustic metamaterial, comprising a substrate, an elastic element and a tunable mass element.

[0039] Specifically, the substrate is made of metal material, the elastic element is arranged on the substrate and is made of non-metallic material, and the tunable mass element is arranged on the elastic element and is made of metal material. The substrate, the elastic element and the tunable mass element can form a unit cell structure with a vibration reduction function, and the size of the unit cell structure is determined based on the required vibration reduction effect and the size of the installation location. Multiple unit cell structures are arranged in an array in sequence, and adjacent substrates are fixedly connected to form an acoustic metamaterial vibration reduction structure. The more unit cell structures are arrayed in a limited plane space, the more obvious the vibration reduction effect is.

[0040] In this embodiment, the substrate is made of aluminum metal material, the elastic element is made of silicone rubber non-metal material, and the tunable mass element is made of steel metal material. The substrate is rectangular, with a lattice constant of 30 mm and a thickness of 3 mm. The elastic element and the tunable mass element are both cylindrical, with a radius of 12 mm and a thickness of 2.5 mm-4.5 mm. The elastic element and the tunable mass element are provided on both sides of the substrate.

[0041] When the size of the substrate and the tunable mass element remain unchanged, the thickness of the elastic element is set to 2.5 mm, 3 mm, 3.5 mm, 4 mm and 4.5 mm respectively, and the vibration reduction effect of the acoustic metamaterial vibration reduction structure is calculated. The results are as follows: Figure 3 As shown. Figure 3It can be seen from the curve that when the thickness of the silicone rubber is 3mm, the corresponding attenuation is the largest, and the corresponding attenuation frequency range is also relatively wide. Compared with the thickness of 2.5mm, it can achieve vibration attenuation of about 400Hz, and at the same time includes vibration attenuation of 500Hz, 600Hz and close to 700Hz. And it can be known that if the thickness of the elastic element continues to increase or decrease according to this trend, it will be detrimental to the vibration reduction of the overall structure. If it is too thick, the vibration reduction frequency range will be reduced, the vibration attenuation degree will also be reduced, and the tunable mass element will not play its role. If it is too thin, it will affect the connection strength between the tunable mass element and the substrate.

[0042] When the sizes of the substrate and the elastic element remain unchanged, the thickness of the tunable mass element is set to 2.5 mm, 3 mm, 3.5 mm, 4 mm and 4.5 mm respectively, and the vibration reduction effect of the acoustic metamaterial vibration reduction structure is calculated. The results are as follows: Figure 4 As shown. Figure 4 It can be seen that, unlike the effect of the aforementioned change in the thickness of the silicone rubber on vibration attenuation, the change in the thickness of the mass element has little effect on the frequency range of vibration attenuation, and the degree of vibration attenuation is similar. However, as the thickness of the mass element increases, it is easier to achieve vibration reduction in the low-frequency range. Therefore, the effect of the change in the thickness of the elastic element on vibration reduction is greater than that of the change in the thickness of the mass element on vibration reduction.

[0043] In summary, setting the thickness of the tunable mass element and the thickness of the elastic element to 3 mm and arranging them in arrays as many as possible can both ensure the rigidity of the structure and maximize its vibration reduction effect.

[0044] The present invention also provides an application of a wind turbine vibration isolation structure, such as Figure 5 As shown, the above-mentioned wind turbine vibration isolation structure based on adjustable acoustic metamaterial is adopted, and the acoustic metamaterial vibration reduction structure is fixedly installed on the supporting steel frame by bolts, and is fixedly connected to the unit equipment through the supporting steel frame.

[0045] When the supporting steel frame of the unit equipment is vibrated, its vibration energy will be transmitted in the form of elastic waves. Since the substrate is fixedly connected to the supporting steel frame, the substrate will be affected by the external force f, and the tuned mass element will exert an internal force f' on the substrate in the opposite direction, causing the substrate to reciprocate under the external and internal forces. When the external force has the same frequency as the internal force, the external force will be offset by the internal reaction force, making the substrate relatively static. At this time, the external elastic wave energy is absorbed by the internal resonance unit, and the external force is localized to form a starting frequency ω1. As the frequency of the external force continues to increase, the resonance mode gradually weakens, and the resultant force on the substrate no longer tends to zero until this balance is broken and the local resonance mode disappears completely, forming a cutoff frequency ω2.

[0046] Specifically, the starting frequency of the frequency band gap is ω1, the cutoff frequency is ω2, the mass of the substrate is m2, the mass of the tunable mass element is m1, the equivalent stiffness of the elastic element is k, and the starting frequency and cutoff frequency of the frequency band gap are expressed as follows:

[0047]

[0048] The modes of the starting frequency and the cutoff frequency of the unit cell structure are as follows Figure 6 and Figure 7 As shown, the simplified model of vibration reduction equivalent is as follows Figure 8 shown.

[0049] When the vibration frequency of the external force falls into the frequency band gap ω1~ω2, the acoustic metamaterial vibration isolation structure can respond to the vibration in this frequency band, localize the external vibration capacity, and prevent the vibration energy from continuing to propagate, thereby achieving a vibration reduction effect.

[0050] Compared with traditional vibration isolators, the wind turbine vibration isolation structure based on the adjustable acoustic metamaterial can respond to vibrations in a wider frequency range and achieve vibration suppression at the corresponding frequency, rather than just responding to vibrations at a specific frequency. Even if the vibration is relatively complex, it can still play a good role in vibration reduction. After applying it to wind turbine equipment, it can achieve overall vibration reduction without changing the original structure of the equipment, thereby significantly reducing structural damage and failure of precision components of electrical equipment such as control cabinets caused by vibration, reducing equipment failure rate, improving equipment operation reliability, and reducing on-site repair and maintenance rates and operation and maintenance costs.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. 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 replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A wind turbine vibration isolation structure based on adjustable acoustic metamaterials, characterized in that: including a substrate, an elastic element, and a tunable mass element; The substrate is made of metal material; The elastic element is arranged on the substrate and is made of non-metallic material; The tunable mass element is arranged on the elastic element and is made of metal material.

2. The wind turbine vibration isolation structure based on adjustable acoustic metamaterial according to claim 1, characterized in that: The base plate is made of aluminum metal material.

3. The wind turbine vibration isolation structure based on adjustable acoustic metamaterial according to claim 1, characterized in that: The elastic element is made of silicone rubber non-metallic material.

4. The wind turbine vibration isolation structure based on adjustable acoustic metamaterial according to claim 1, characterized in that: The tunable mass element is made of steel metal material.

5. A wind turbine vibration isolation structure based on adjustable acoustic metamaterial according to any one of claims 1 to 4, characterized in that: The plurality of substrates are arranged in an array in sequence, and adjacent substrates are fixedly connected.

6. The wind turbine vibration isolation structure based on adjustable acoustic metamaterial according to claim 5, characterized in that: The substrate is rectangular, has a lattice constant of 30 mm and a thickness of 3 mm; The elastic element and the tunable mass element are both cylindrical, with a radius of 12 mm and a thickness of 2.5 mm-4.5 mm.

7. The wind turbine vibration isolation structure based on adjustable acoustic metamaterial according to claim 6, characterized in that: Elastic elements and tunable mass elements are arranged on both sides of the substrate.

8. An application of a wind turbine vibration isolation structure, using the wind turbine vibration isolation structure based on adjustable acoustic metamaterials as claimed in claim 7, characterized in that: The structure is fixedly installed on the supporting steel frame and fixedly connected to the unit equipment through the supporting steel frame.

9. The vibration reduction application of the wind turbine vibration isolation structure according to claim 8 is characterized by: When the supporting steel frame is vibrated, the substrate is subjected to external force, and the tunable mass element applies internal force to the substrate in the opposite direction, causing the substrate to vibrate reciprocatingly. When the frequency of the external force falls into the frequency band gap of the structure, the structure can localize the external force, preventing the vibration energy from continuing to propagate.

10. The vibration reduction application of the wind turbine vibration isolation structure according to claim 9, characterized in that: The starting frequency of the frequency band gap is ω1, the cutoff frequency is ω2, the mass of the substrate is m2, the mass of the tunable mass element is m1, the equivalent stiffness of the elastic element is k, and the starting frequency and cutoff frequency of the frequency band gap are expressed as follows:

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