Metasurface sound absorption device

Abstract

This invention relates to the field of wind power noise reduction technology and discloses a metamorphic sound-absorbing device, comprising a protective layer and a sound-absorbing layer, with multiple sound-permeable holes; a mounting cavity is located on the back side of the protective layer, and multiple sound-absorbing blocks are arranged at intervals along a first direction within the mounting cavity. Gaps exist between the sound-absorbing blocks and the protective layer, between the sound-absorbing blocks and the inner wall of the mounting cavity, and between the sound-absorbing blocks and adjacent sound-absorbing blocks. The side of each sound-absorbing block away from the protective layer has a first opening and a second opening. The first opening extends upward to form a first silencing channel, and the second opening extends upward to form a second silencing channel, which extends to partially enclose the first silencing channel. This disclosed metamorphic sound-absorbing device can extend the sound wave propagation path within a relatively thin thickness, improving the sound absorption and noise reduction effect, and is suitable for sound absorption treatment in space-constrained scenarios such as wind turbine nacelles.

Description

Technical Field

[0001] This invention belongs to the field of wind power noise reduction technology, specifically relating to a metamorphic sound absorption device. Background Technology

[0002] In related technologies, sound absorption and noise reduction inside wind turbine nacelles are mostly achieved by laying traditional porous sound-absorbing materials. However, the sound absorption effect of such materials on mid- and low-frequency noise depends on a relatively large thickness, which is incompatible with the compact installation space inside the nacelle. At the same time, traditional materials are prone to deformation and performance degradation under long-term use in environments with changes in temperature and humidity, dust, and vibration in the nacelle. Moreover, the installation method is mostly on-site cutting and pasting, which results in poor modularity and consistency, making it unsuitable for standardized application and on-site modification. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a metamorphic sound-absorbing device that can extend the sound wave propagation path within a relatively thin thickness, improving sound absorption and noise reduction effects, and is easy to install.

[0004] The metamorphic sound-absorbing device of this invention includes:

[0005] The protective layer has multiple sound-permeable holes; A sound-absorbing layer is disposed on the back side of the protective layer. The sound-absorbing layer has a mounting cavity. Multiple sound-absorbing blocks are arranged at intervals along a first direction in the mounting cavity. There are gaps between the sound-absorbing blocks and the protective layer, between the sound-absorbing blocks and the inner wall of the mounting cavity, and between the sound-absorbing blocks and adjacent sound-absorbing blocks along the first direction. The sound-absorbing block has a first opening and a second opening spaced apart along the first direction on the side away from the protective layer. The first opening extends upward to form a first silencing channel, and the second opening extends upward to form a second silencing channel. The second silencing channel extends to a shape that partially encloses the first silencing channel.

[0006] The metamorphic sound-absorbing device of this disclosure, through the stacked arrangement of a protective layer and a sound-absorbing layer, and the spaced arrangement of multiple sound-absorbing blocks within the sound-absorbing layer, allows sound waves to enter the mounting cavity through the sound-permeable holes in the protective layer, and to propagate and reflect multiple times in the gaps around the sound-absorbing blocks and in the silencing channels inside the sound-absorbing blocks. The semi-enclosed design of the second silencing channel over the first silencing channel creates a more complex propagation path for the sound waves between the two channels, thereby effectively extending the sound path within the relatively thin device thickness, enhancing sound energy dissipation, and improving the sound absorption and noise reduction capabilities within a limited space.

[0007] In some embodiments, the wall of the first anechoic channel is bent.

[0008] The superstructure sound-absorbing device of this embodiment, through the bent shape of the wall of the first sound-absorbing channel, causes the sound wave to be reflected and redirected multiple times when propagating in the channel, effectively extending the actual propagation path of the sound wave and increasing the sound energy loss along the way.

[0009] In some embodiments, the wall of the second anechoic channel is bent.

[0010] The superstructure sound-absorbing device of this embodiment further enhances the complexity of the sound wave propagation path and the adequacy of sound energy loss by setting the wall of the second sound-absorbing channel to be bent as well, forming a double-bent channel cooperative layout with the first sound-absorbing channel.

[0011] In some embodiments, after the second anechoic channel extends upward from the second opening, it bends and extends towards the direction close to the first anechoic channel, and extends downward to the vicinity of one side of the sound-absorbing block, so as to form a semi-enclosure of the first anechoic channel.

[0012] The superstructure sound-absorbing device of this embodiment, through the setting of the above-mentioned extended path, allows the second anechoic channel to spatially surround at least a portion of the first anechoic channel, forming a semi-nested channel layout, enabling acoustic coupling between the two anechoic channels, enriching the propagation and interference mechanism of sound waves between different channels, and improving the sufficiency of sound energy attenuation within a limited volume.

[0013] In some embodiments, a backplate layer is further included, which is disposed on the back side of the sound-absorbing layer and is used to seal the back of the mounting cavity.

[0014] The superstructure sound-absorbing device of this disclosure, through the setting of the back plate layer, makes the mounting cavity form a closed or semi-closed acoustic cavity structure, providing a clear acoustic boundary for the sound-absorbing channel, which is beneficial to improving the sound absorption performance of the target frequency band, and at the same time providing structural rigidity support for the device.

[0015] In some embodiments, the back panel layer has an attachment mounting layer on its back side for attaching the metamaterial sound-absorbing device to the surface to be installed.

[0016] The superstructure sound-absorbing device of this disclosure, through the setting of the attached mounting layer, allows the device to be directly attached to the inner wall of the wind turbine nacelle or the surface of the equipment without the need for additional brackets, making installation convenient.

[0017] In some embodiments, at least one of the channel length, channel width, and number of folds of the first and second silencing channels within at least two of the sound-absorbing blocks is different from each other.

[0018] The superstructure sound-absorbing device of this disclosure differentiates the silencing channel parameters of different sound-absorbing blocks, so that each sound-absorbing block corresponds to a different sound absorption peak frequency, thereby widening the sound absorption bandwidth of the entire device and achieving a wideband sound absorption effect.

[0019] In some embodiments, the protective layer and the sound-absorbing layer are made of flame-retardant materials.

[0020] The superstructure sound-absorbing device of this disclosure meets the fire safety requirements of the wind turbine nacelle by selecting flame-retardant materials, thereby improving the reliability of long-term operation.

[0021] According to a second aspect of this disclosure, a wind turbine nacelle is provided, including an inner wall of the nacelle and a superstructure sound-absorbing device as described in any of the above embodiments, wherein the superstructure sound-absorbing device is attached to the inner wall of the nacelle, the equipment housing, the cooling unit housing, or the outer wall of the air duct.

[0022] The wind turbine nacelle of this disclosure, by adopting the above-mentioned superstructure sound absorption device, can achieve effective sound absorption and noise reduction in a compact nacelle interior space by thin-film attachment. It is easy to install and suitable for on-site retrofitting of existing wind turbine units. Attached Figure Description

[0023] Figure 1 This is an overall schematic diagram of the present invention.

[0024] Figure 2 This is a schematic diagram of the sound-absorbing block in this invention.

[0025] Figure 3 This is a schematic diagram of the protective layer in this invention.

[0026] Figure 4 This is a schematic diagram of the installation of the sound-absorbing block in the mounting cavity in this invention.

[0027] Figure label: 1. Protective layer; 11. Sound transmission holes; 2. Sound-absorbing layer; 21. Mounting cavity; 22. Sound-absorbing block; 221. First opening; 222. Second opening; 223. First silencing channel; 224. Second silencing channel; 3. Back panel layer; 4. Apply the mounting layer. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] The disclosed metamorphic sound-absorbing device can be applied inside wind turbine nacelles, and is used to attach to surfaces such as the inner wall of the nacelle, equipment housing, cooling unit outer shell, or outer wall of the air duct to absorb and reduce noise inside the nacelle. Of course, this metamorphic sound-absorbing device can also be applied to other scenarios where space is limited and thin-film sound absorption treatment is required, such as various equipment rooms, pipe outer walls, and industrial plants.

[0030] like Figure 1-4 As shown, the superstructure sound-absorbing device of this embodiment includes a protective layer 1 and a sound-absorbing layer 2. The protective layer 1 has a plurality of sound-permeable holes 11. The sound-absorbing layer 2 is disposed on the back side of the protective layer 1 and has a mounting cavity 21. A plurality of sound-absorbing blocks 22 are arranged at intervals along a first direction in the mounting cavity 21. There are gaps between the sound-absorbing blocks 22 and the protective layer 1, between the sound-absorbing blocks 22 and the inner wall of the mounting cavity 21, and between the sound-absorbing blocks 22 and adjacent sound-absorbing blocks 22 along the first direction. The side of the sound-absorbing block 22 away from the protective layer 1 has a first opening 221 and a second opening 222 arranged at intervals along the first direction. The first opening 221 extends upward to form a first sound-absorbing channel 223, and the second opening 222 extends upward to form a second sound-absorbing channel 224. The second sound-absorbing channel 224 extends to a shape that partially encloses the first sound-absorbing channel 223.

[0031] The superstructure sound-absorbing device of this embodiment, through the stacked arrangement of the protective layer 1 and the sound-absorbing layer 2, and the spaced arrangement of multiple sound-absorbing blocks 22 within the sound-absorbing layer 2, allows sound waves to enter the mounting cavity 21 through the sound-permeable holes 11 of the protective layer 1, and propagate and reflect multiple times in the gaps around the sound-absorbing blocks 22 and in the first silencing channel 223 and the second silencing channel 224 inside the sound-absorbing blocks 22. The semi-enclosed design of the second silencing channel 224 on the first silencing channel 223 creates a more complex propagation path for the sound waves between the two channels, thereby effectively extending the sound path within the relatively thin device thickness, enhancing sound energy dissipation, and improving the sound absorption and noise reduction effect.

[0032] Specifically, the first direction refers to the arrangement direction of the multiple sound-absorbing blocks 22. In the application scenario of wind turbine nacelles, this first direction is usually the left-right direction. The sound-absorbing blocks 22 are spaced apart along this direction, so that gaps are formed between adjacent sound-absorbing blocks 22 to allow sound waves to pass through.

[0033] Furthermore, the gaps between the sound-absorbing block 22 and the protective layer 1, the gap between the sound-absorbing block 22 and the bottom wall of the mounting cavity 21, and the gaps between adjacent sound-absorbing blocks 22 are interconnected. After sound waves enter the mounting cavity 21, they can propagate in the aforementioned gaps and enter the silencing channels inside each sound-absorbing block 22 via the first opening 221 and the second opening 222. Through the combined arrangement of the aforementioned gaps and silencing channels, the propagation path of sound waves inside the device is extended, and the sound absorption efficiency is further improved.

[0034] In some embodiments, the wall of the first anechoic channel 223 is bent.

[0035] The superstructure sound-absorbing device of this embodiment, through the bent shape of the wall of the first sound-absorbing channel 223, causes the sound wave to be reflected and redirected multiple times when propagating in the channel, effectively extending the actual propagation path of the sound wave in the channel and increasing the sound energy loss along the path.

[0036] In some embodiments, the wall of the second anechoic channel 224 is bent. The meta-absorbing device of this disclosure, by also having a bent wall in the second anechoic channel 224, forms a double-bent channel layout with the first anechoic channel 223, further enhancing the complexity of the sound wave propagation path and the adequacy of sound energy loss within the entire sound-absorbing block 22.

[0037] In some embodiments, the second anechoic channel 224 extends upward from the second opening 222, then bends and extends towards the first anechoic channel 223, and extends downward to the vicinity of the aforementioned side of the sound-absorbing block 22, thus forming a semi-enclosed enclosure of the first anechoic channel 223. In the metamorphic sound-absorbing device of this embodiment, through the aforementioned extension path, the second anechoic channel 224 spatially surrounds at least a portion of the first anechoic channel 223, forming a semi-nested channel layout. This semi-enclosed structure allows acoustic coupling between the two anechoic channels through shared or adjacent walls, enriching the propagation and interference mechanisms of sound waves between different channels and improving the sufficiency of sound energy attenuation within a limited volume.

[0038] In some embodiments, the metamorphic sound-absorbing device further includes a back plate layer 3, which is disposed on the back side of the sound-absorbing layer 2 and is used to seal the back of the mounting cavity 21. The metamorphic sound-absorbing device of this disclosure, through the provision of the back plate layer 3, enables the mounting cavity 21 to form a closed or semi-closed acoustic cavity structure, providing a clear acoustic boundary for the sound-absorbing channel inside the sound-absorbing block 22. This facilitates the formation of sound reflection and local resonance effects within the cavity, thereby improving the sound absorption performance in the target frequency band. Simultaneously, the back plate layer 3 provides structural rigidity support for the entire sound-absorbing device, improving the flatness and deformation resistance of the device.

[0039] In some embodiments, the back side of the back panel layer 3 is provided with an attachment mounting layer 4 for attaching the superstructure sound-absorbing device to the surface to be installed. The superstructure sound-absorbing device of this embodiment, through the attachment mounting layer 4, allows the device to be directly attached to the inner wall of the wind turbine nacelle or the surface of the equipment, eliminating the need for additional supports or complex on-site construction, thus facilitating installation. The attachment mounting layer 4 can be a pressure-sensitive adhesive layer, structural adhesive layer, or double-sided adhesive layer that is temperature-resistant, moisture-resistant, and aging-resistant. Magnetic suction components or mechanically assisted fixing structures can also be added to ensure installation reliability during long-term operation.

[0040] In some embodiments, at least one of the channel length, channel width, and number of folds of the first silencing channel 223 and the second silencing channel 224 within at least two sound-absorbing blocks 22 is different from each other. The meta-absorbing device of this disclosure, by differentiating the silencing channel parameters of different sound-absorbing blocks 22, allows each sound-absorbing block 22 to correspond to a different sound absorption peak frequency, thereby widening the sound absorption bandwidth of the entire device and achieving a broadband sound absorption effect.

[0041] In some embodiments, the protective layer 1 and the sound-absorbing layer 2 are made of flame-retardant materials. The superstructure sound-absorbing device of this disclosure, through the selection of flame-retardant materials, enables the device to meet the fire safety requirements inside the wind turbine nacelle. The protective layer 1 can be made of flame-retardant metal plate, flame-retardant composite material plate, or flame-retardant engineering plastic plate, and the sound-absorbing blocks 22 in the sound-absorbing layer 2 can be made of flame-retardant engineering plastics, flame-retardant composite materials, or lightweight metals through injection molding, compression molding, additive manufacturing, or CNC machining.

[0042] Specifically, the sound-permeable holes 11 of the protective layer 1 are micro-perforations. At least one of the pore diameter, pore spacing, and open area ratio of the micro-perforations can be designed according to the target sound absorption frequency band. The micro-perforations enable the protective layer 1 to form a certain acoustic impedance and acoustic quality, which, together with the mounting cavity 21 and the anechoic channel behind it, forms a composite sound absorption structure, improving sound absorption efficiency. At the same time, the micro-perforations can prevent dust, large particulate impurities, and oil stains from directly entering the interior of the sound-absorbing layer 2, reducing the risk of blockage of the internal anechoic channel.

[0043] Furthermore, multiple superstructure sound-absorbing devices can be spliced ​​together. The edges of the superstructure sound-absorbing devices are provided with splicing structures, which include at least one of splicing edges, positioning bosses, positioning grooves, snap-fit ​​edges, and overlapping edges. Through the splicing structure, the superstructure sound-absorbing device of this disclosure allows multiple devices to be flexibly combined inside the wind turbine nacelle according to the noise source distribution and available space, forming a large-area continuous sound-absorbing area or a dense arrangement targeting local noise hotspots, achieving standardized modular installation.

[0044] According to a second aspect of this disclosure, a wind turbine nacelle is provided, including an inner wall of the nacelle and a superstructure sound-absorbing device according to any of the above embodiments. The superstructure sound-absorbing device is attached to the inner wall of the nacelle, the equipment housing, the cooling unit housing, or the outer wall of the air duct. The wind turbine nacelle of this disclosure, by employing the aforementioned superstructure sound-absorbing device, can achieve effective sound absorption and noise reduction in a compact nacelle interior space through a thin-film attachment, offering convenient installation and suitability for on-site retrofitting of existing wind turbine units.

[0045] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0047] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0049] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0050] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A metamorphic sound-absorbing device, characterized in that, include: The protective layer (1) is provided with a plurality of sound-permeable holes (11). The sound-absorbing layer (2) is disposed on the back side of the protective layer (1). The sound-absorbing layer (2) has a mounting cavity (21). Multiple sound-absorbing blocks (22) are arranged at intervals along a first direction in the mounting cavity (21). There are gaps between the sound-absorbing blocks (22) and the protective layer (1), between the sound-absorbing blocks (22) and the inner wall of the mounting cavity (21), and between the sound-absorbing blocks (22) and adjacent sound-absorbing blocks (22) along the first direction. The sound-absorbing block (22) has a first opening (221) and a second opening (222) spaced apart along the first direction on one side away from the protective layer (1). The first opening (221) extends upward to form a first silencing channel (223), and the second opening (222) extends upward to form a second silencing channel (224). The second silencing channel (224) extends to a shape that partially encloses the first silencing channel (223).

2. The metamorphic sound-absorbing device according to claim 1, characterized in that, The wall of the first silencing channel (223) is bent.

3. The metamorphic sound-absorbing device according to claim 2, characterized in that, The wall of the second silencing channel (224) is bent.

4. The metamorphic sound-absorbing device according to claim 3, characterized in that, After the second silencing channel (224) extends upward from the second opening (222), it bends and extends towards the first silencing channel (223), and extends downward to the vicinity of one side of the sound-absorbing block (22) to form a semi-enclosure of the first silencing channel (223).

5. The metamorphic sound-absorbing device according to claim 1, characterized in that, It also includes a back plate layer (3), which is located on the back side of the sound-absorbing layer (2) and is used to seal the back of the mounting cavity (21).

6. The metamorphic sound-absorbing device according to claim 5, characterized in that, The back panel layer (3) has an attachment layer (4) on its back side, which is used to attach the superstructure sound-absorbing device to the surface to be installed.

7. The metamorphic sound-absorbing device according to claim 1, characterized in that, The channel length, channel width, and number of folds of the first silencing channel (223) and the second silencing channel (224) within at least two of the sound-absorbing blocks (22) are different from each other.

8. The metamorphic sound-absorbing device according to any one of claims 1-7, characterized in that, The protective layer (1) and the sound-absorbing layer (2) are made of flame-retardant materials.

9. A wind turbine nacelle, characterized in that, It includes the cabin interior wall and the superstructure sound-absorbing device as described in any one of claims 1-9, wherein the superstructure sound-absorbing device is attached to the cabin interior wall, equipment housing, cooling unit housing, or air duct exterior wall.

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