Construction method and structure of nested micro-perforated plate composite structure

Abstract

The invention discloses a construction method of a nested micro-perforated plate composite structure, and discloses a structure applying the construction method of the nested micro-perforated plate composite structure, and the construction method of the nested micro-perforated plate composite structure can excite a plurality of sound absorption peaks through the combination of a plurality of micro-perforated plate sound absorption structures. Continuous sound absorption in a broadband range is achieved by reasonably adjusting structural parameters, the sound absorption efficiency of 100-500 Hz is effectively improved, the low-frequency-band sound absorption broadband is widened, the low-frequency-band sound absorption device can be applied to low-frequency noise reduction of power grid equipment, and interference of noise to the outside is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of noise control, and in particular to a construction method and structure of a nested micro-perforated plate composite structure. Background Art

[0002] Microperforated panels offer significant advantages for wide-ranging applications due to their simple and efficient low-frequency sound absorption capabilities. However, single-layer microperforated panels have a narrow absorption band and a single impedance, making them incapable of achieving broadband, continuous sound absorption. Double-layer microperforated panels, by connecting two microperforated panels in series, can achieve a certain degree of broadband sound absorption through specific parameter design. However, this also involves a narrow range of parameters within a fixed structural dimension, limiting the design and construction space.

[0003] Research on microperforated plate-based sound-absorbing structures has focused significantly on the design of the back cavity and the materials (structures) within it. To achieve continuous sound absorption within a specific frequency band, the microperforated plate cavity must be designed to meet continuous impedance requirements. Existing technologies lack the ability to achieve continuous sound absorption across multiple frequency bands. Summary of the Invention

[0004] The present invention aims to address at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method for constructing a nested micro-perforated plate composite structure. This method, through the combination of multiple micro-perforated plate sound-absorbing structures, can stimulate multiple sound absorption peaks. By rationally adjusting the structural parameters, continuous sound absorption can be achieved across a wide frequency range. This effectively improves the sound absorption efficiency from 100Hz to 500Hz, broadens the low-frequency sound absorption bandwidth, and can be applied to low-frequency noise reduction in power grid equipment, reducing noise interference.

[0005] The present invention also proposes a structure using the above-mentioned nested micro-perforated plate composite structure construction method.

[0006] According to the first embodiment of the present invention, the method for constructing a nested micro-perforated plate composite structure comprises the following steps:

[0007] Constructing a three-layer nested composite structure consisting of a first microperforated plate-cavity structure, a second microperforated plate-cavity structure, and a third microperforated plate-cavity structure, wherein the second microperforated plate-cavity structure is embedded in the first microperforated plate-cavity structure, and the third microperforated plate-cavity structure is embedded in the second microperforated plate-cavity structure;

[0008] Set the cavity thickness of each layer to H1, H2, and H3, and satisfy H1>H2>H3;

[0009] Set the diameters of each layer of micro-perforated plates to D1, D2, and D3, respectively, and satisfy D1>D2>D3;

[0010] The final parameter combination of each layer structure is determined through parameter optimization.

[0011] The nested micro-perforated plate composite structure construction method according to the present invention has at least the following beneficial effects: It stimulates multiple sound absorption peaks through the combination of multiple micro-perforated plate sound absorption structures, and achieves continuous sound absorption across a wide frequency range by rationally adjusting structural parameters. This method is particularly applicable to the field of low-frequency noise reduction in power grid equipment, effectively reducing the impact of 100Hz-500Hz noise and reducing noise interference to the outside world.

[0012] According to some embodiments of the present invention, in the step of determining the final parameter combination of each layer structure by parameter optimization, the optimization goal is to maximize the average sound absorption coefficient in the frequency band of 100 Hz-500 Hz, wherein:

[0013] H1≤100mm; the thickness t of each layer of micro-perforated plate is 0.6mm to 2mm, the pore diameter d is 0.6mm to 2mm, and the perforation rates σ1, σ2, and σ3 are 1% to 5%;

[0014] According to some embodiments of the present invention, the number of perforations in each layer of the micro-perforated plate is calculated by the following formula:

[0015]

[0016] Where σ is the perforation rate, n holes is the number of perforations; r is the perforation radius, r = d / 2; S is the area of the micro-perforated plate.

[0017] According to some embodiments of the present invention, the optimization objective is achieved through the following model:

[0018]

[0019] Among them, α(f i ) is the frequency f i The sound absorption coefficient under , the step size Δf = 1Hz, N is the number of frequencies.

[0020] According to some embodiments of the present invention, the diameter D1 of the first micro-perforated plate-cavity structure is set to a fixed value C, where C is determined according to an actual application scenario.

[0021] According to some embodiments of the present invention, the method is applied to low-frequency noise reduction of power grid equipment, including noise control of box-type substations.

[0022] According to the second embodiment of the present invention, the nested micro-perforated plate composite structure is characterized in that the structure includes:

[0023] The first layer of micro-perforated plate has a cavity thickness H1 of 96 mm, a diameter D1 of 96 mm, a plate thickness of 1.8 mm, and 145 perforations;

[0024] The second layer of micro-perforated plate has a cavity thickness H2 of 71 mm, a diameter D2 of 64 mm, a plate thickness of 1.7 mm, and 38 perforations;

[0025] The third layer of micro-perforated plate has a cavity thickness H3 of 51 mm, a diameter D3 of 32 mm, a plate thickness of 2.0 mm, and 7 perforations;

[0026] The aperture is 0.8mm.

[0027] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0029] Figure 1 Schematic diagram of a nested micro-perforated plate structure according to an embodiment of the present invention;

[0030] Figure 2 Parameter calculation and experimental sound absorption coefficient curve of the nested micro-perforated plate provided in the embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0032] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0033] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0034] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0035] Example 1

[0036] In order to achieve a certain broadband continuous sound absorption effect, the present application provides a method for constructing a nested micro-perforated plate composite structure, which excites multiple sound absorption peaks by combining multiple micro-perforated plate sound absorption structures, and achieves continuous sound absorption in a wide frequency range by reasonably adjusting the structural parameters. The method includes at least the following steps:

[0037] Step S100 : constructing a three-layer nested composite structure consisting of a first micro-perforated plate-cavity structure, a second micro-perforated plate-cavity structure, and a third micro-perforated plate-cavity structure.

[0038] The structure consists of three micro-perforated plate-cavities, the second micro-perforated plate-cavity structure is placed in the first micro-perforated plate-cavity structure, and the third micro-perforated plate-cavity structure is placed in the second micro-perforated plate-cavity structure;

[0039] Step S200: setting the thickness of each layer of cavity.

[0040] The cavity thicknesses of the first micro-perforated plate-cavity, the second micro-perforated plate-cavity, and the third micro-perforated plate-cavity structures are H1, H2, and H3, respectively, and satisfy H1>H2>H3;

[0041] Step S300: setting the diameter of each layer of micro-perforated plate.

[0042] The diameters of the first micro-perforated plate-cavity, the second micro-perforated plate-cavity, and the third micro-perforated plate-cavity structures are D1, D2, and D3, respectively, and satisfy D1>D2>D3;

[0043] Furthermore, since the structural parameters that affect the sound absorption performance of the microperforated plate include the thickness of the microperforated plate, the perforation radius, the perforation rate, and the thickness of the cavity behind the plate, in order to ensure that better sound absorption performance is obtained under a certain structural thickness, the embodiment of the present application provides a first microperforated plate-cavity structure with a thickness H1 ≤ 100 mm, and the optimized parameters are the second and third microperforated plate-cavity thicknesses H2 and H3, the cavity diameters D1, D2, and D3 of each layer of microperforated plate, the thickness of the microperforated plate, the perforation radius, and the perforation rates σ1, σ2, and σ3 of each layer of microperforated plate, wherein the thickness and perforation diameter of each layer of microperforated plate are set to the same value, which are set as t and d respectively;

[0044] The diameter D1 of the cavity of the first micro-perforated plate is set to a fixed value C, which is determined according to actual application needs;

[0045] Step S400: Determine the final parameter combination of each layer structure through parameter optimization.

[0046] With the average sound absorption coefficient of the structure within 100Hz-500Hz as the goal, the following model is established:

[0047]

[0048] In the formula, α(f i ) is the frequency f i The sound absorption coefficient under , the step size Δf = 1Hz, N is the number of frequencies.

[0049] Furthermore, in order to achieve more precise parameter control, the parameters of each layer of micro-perforated plate structure are optimized and the range of each parameter is restricted: 100≥H1>H2>H3>0, C=D1>D2>D3>0, the thickness of the perforated plate t is 0.6mm~2mm, the perforation diameter d is 0.6mm~2mm, and the perforation rates σ1, σ2, and σ3 are in the range of 1%~5%.

[0050] Using the number of perforations instead of the perforation rate for optimization is more conducive to subsequent processing and manufacturing. The perforation rate of the micro-perforated plate can be calculated by formula (2):

[0051]

[0052] Where, σ is the perforation rate of the micro-perforated plate; n holes is the number of perforations; r is the perforation radius, r = d / 2; S is the area of the micro-perforated plate.

[0053] The sound absorption coefficient of the nested micro-perforated plate is calculated based on the thickness, perforation radius, perforation rate and thickness of the cavity behind the plate. max The structural parameters of each layer of micro-perforated plate-cavity are obtained at the maximum value, thereby forming an optimal nested micro-perforated plate composite structure.

[0054] Example 2

[0055] Based on the method provided in the first embodiment above, this application provides a nested micro-perforated plate structure with the optimization goal of maximizing the average sound absorption coefficient within the 100Hz-500Hz frequency band. Figure 1 As shown:

[0056] The nested micro-perforated plate structure is designed with a cavity of 96 mm behind the first layer of micro-perforated plates.

[0057] The nested micro-perforated plate structure is designed to conduct experiments in an impedance tube, and the diameter of the first layer of micro-perforated plates is set to 96 mm.

[0058] The nested micro-perforated plate structure is analyzed based on the optimization calculation, and the parameters of each layer of micro-perforated plate are shown in Table 1.

[0059] Table 1 Multi-layer micro-perforated plate structural parameters

[0060]

[0061] The sound absorption coefficient of the multi-layer micro-perforated plate is obtained by simulation calculation. Figure 2 There are three sound absorption peaks in the 100Hz-500Hz frequency band. The peaks are evenly distributed within this frequency band, forming broadband sound absorption. The three peaks achieve continuous and strong sound absorption. The three peaks are at 226Hz, 331Hz, and 429Hz, with sound absorption peak values of 0.8834, 0.9624, and 0.9726 respectively. The sound absorption curves in the 200Hz-500Hz frequency band are all greater than 0.8, and the average sound absorption coefficient in the 100Hz-500Hz frequency band reaches 0.7555.

[0062] Preferably, the first layer of micro-perforated plate cavity thickness generally needs to meet H1 of 80-100 mm, diameter D1 of 80-100 mm, micro-perforated plate thickness of 1-2 mm, and number of perforations of 120-150;

[0063] The second layer of micro-perforated plate has a cavity thickness H2 of 60-80 mm, a diameter D2 of 60-70 mm, a plate thickness of 1-2 mm, and a number of perforations of 30-50;

[0064] The third layer of micro-perforated plate has a cavity thickness H3 of 40 to 60 mm, a diameter D3 of 30 to 40 mm, a plate thickness of 1 to 2 mm, and a perforation number of 0 to 10;

[0065] The aperture is 0.6~0.8mm. It can achieve similar effects.

[0066] The above-described 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. 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, and should all be included in the scope of protection of the present invention.

[0067] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0068] Those skilled in the art will appreciate that all or some of the steps and systems in the method disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. Some physical components or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, and the computer-readable medium can include computer storage media (or non-transitory media) and communication media (or temporary media). As known to those skilled in the art, the term computer storage media is included in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data) and is volatile and non-volatile, removable, and non-removable. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory, or other memory technology, CD-ROM, digital versatile disks (DVD), or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage, or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, communication media typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0069] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the above implementation mode. Technical personnel familiar with the field can also make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A method for constructing a nested micro-perforated plate composite structure, characterized in that: The following steps are involved: Constructing a three-layer nested composite structure consisting of a first microperforated plate-cavity structure, a second microperforated plate-cavity structure, and a third microperforated plate-cavity structure, wherein the second microperforated plate-cavity structure is embedded in the first microperforated plate-cavity structure, and the third microperforated plate-cavity structure is embedded in the second microperforated plate-cavity structure; Set the cavity thickness of each layer to H1, H2, and H3, and satisfy H1>H2>H3; Set the diameters of each layer of micro-perforated plates to D1, D2, and D3, respectively, and satisfy D1>D2>D3; The final parameter combination of each layer structure is determined through parameter optimization.

2. The method according to claim 1, characterized in that In the step of determining the final parameter combination of each layer structure by parameter optimization, the optimization goal is to maximize the average sound absorption coefficient in the frequency band of 100 Hz-500 Hz, wherein: H1≤100mm; the thickness t of each layer of micro-perforated plate is 0.6mm to 2mm, the aperture d is 0.6mm to 2mm, and the perforation rates σ1, σ2, and σ3 are 1% to 5%.

3. The construction method according to claim 1, characterized in that: The number of perforations in each layer of the micro-perforated plate is calculated by the following formula: Where σ is the perforation rate, n holes is the number of perforations; r is the perforation radius, r = d / 2; S is the area of the micro-perforated plate.

4. The construction method according to claim 1, characterized in that: The optimization goal is achieved through the following model: Among them, α(f i ) is the frequency f i The sound absorption coefficient under , the step size Δf = 1Hz, N is the number of frequencies.

5. The construction method according to claim 1, characterized in that: The diameter D1 of the first micro-perforated plate-cavity structure is set to a fixed value C, and C is determined according to the actual application scenario.

6. The construction method according to claim 1, characterized in that: The method is applied to low-frequency noise reduction of power grid equipment, including noise control of box-type substations.

7. A nested micro-perforated plate composite structure prepared according to the method according to any one of claims 1 to 5, characterized in that: include: The first layer of micro-perforated plate has a cavity thickness H1 of 80-100 mm, a diameter D1 of 80-100 mm, a plate thickness of 1-2 mm, and a number of perforations of 120-150; The second layer of micro-perforated plate has a cavity thickness H2 of 60-80 mm, a diameter D2 of 60-70 mm, a plate thickness of 1-2 mm, and a number of perforations of 30-50; The third layer of micro-perforated plate has a cavity thickness H3 of 40 to 60 mm, a diameter D3 of 30 to 40 mm, a plate thickness of 1 to 2 mm, and a perforation number of 0 to 10; The pore diameter is 0.6~0.8mm.

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