A conical perforated plate-gradient cavity multi-frequency sound absorber

Abstract

The utility model relates to noise control technical field especially relates to a kind of conical perforated plate-gradient cavity multi-frequency sound absorber.The sound absorber is composed of conical perforated plate and gradient cavity component two parts;The sound absorber is dedicated to significantly improve the sound absorption effect of typical low-frequency noise of transformer substation at 100-500Hz discrete characteristic frequency.This sound absorption structure design is simple, easy to process, install and maintain, and cost controllable.Through the accurate regulation of conical hole size and the optimization of cavity gradient design, the sound absorption performance at the fundamental frequency can be flexibly adjusted.

Description

Technical Field

[0001] This utility model relates to the field of noise control technology, and in particular to a tapered perforated plate-gradient cavity multi-frequency sound absorber. Background Technology

[0002] Noise pollution control is an important aspect of ecological civilization construction and is closely related to the quality of life of the people and the sustainable development of the economy and society. With accelerated urbanization and increased electricity demand, many substations have been built in city centers or densely populated areas. The noise in substations mainly originates from equipment such as transformers and reactors. Low-frequency noise is concentrated in the harmonic frequencies with a fundamental frequency of 50Hz, including 100Hz, 200Hz, 300Hz, 400Hz, and 500Hz. These specific frequency noises are characterized by long wavelengths, long propagation distances, slow attenuation, and strong diffraction capabilities, which can adversely affect the lives of nearby residents and the environment.

[0003] Currently, in the field of sound absorption and noise reduction, widely used sound-absorbing materials can be mainly divided into two categories: porous sound-absorbing materials and resonant sound-absorbing structures. Porous sound-absorbing materials, such as inorganic fiber materials like rock wool and slag wool, are widely used in various noise reduction projects due to their relatively low production cost and good sound absorption performance over a wide frequency range. However, when dealing with low-frequency noise, their sound absorption effect is often unsatisfactory, usually requiring a large thickness to achieve the desired sound absorption effect. This occupies a lot of space in practical applications, increasing construction difficulty and cost. On the other hand, resonant sound-absorbing structures such as ordinary perforated panels, while exhibiting high sound absorption coefficients and good sound absorption performance near specific resonant frequencies, show a rapid decrease in sound absorption coefficients once the sound wave frequency deviates from the resonant peak, resulting in a significant reduction in sound absorption effect. Furthermore, the sound absorption bandwidth of these resonant sound-absorbing structures is relatively narrow, making it difficult to effectively cover the multiple discrete low-frequency noise characteristics generated in places such as substations, thus limiting their practical applications.

[0004] To address the issue of controlling specific frequency noise in scenarios such as substations, there is an urgent need for a tapered perforated plate-gradient cavity multi-frequency sound absorber that can concentrate the absorption of sound energy at specific frequencies, thereby achieving efficient noise reduction of subwavelength superstructures within a compact space.

[0005] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Utility Model Content

[0006] This invention addresses the shortcomings of existing low-frequency noise control technologies in substations by proposing a conical perforated plate-gradient cavity multi-frequency sound absorber. This absorber aims to significantly improve the sound absorption effect of typical low-frequency noise in substations at discrete characteristic frequencies of 100-500Hz. The sound-absorbing structure features a simple design, is easy to manufacture, install, and maintain, and is cost-effective. Through precise control of the conical perforation size and optimization of the cavity gradient design, the sound absorption performance at the fundamental frequency can be flexibly adjusted.

[0007] To achieve the above objectives, this utility model provides the following technical solution: A tapered perforated plate-gradient cavity multi-frequency sound absorber, wherein the sound absorber is composed of two parts: a tapered perforated plate and a gradient cavity assembly; The conical perforated plate is a rigid plate, which is composed of multiple conical perforated plate units, and each conical perforated plate unit is provided with several sets of the same or different conical perforations. The gradient cavity assembly includes a housing, which includes a lower base plate and four end-to-end side plates connecting the lower base plate and a conical perforated plate. A receiving cavity is formed within the housing, and multiple spaced vertical plates of varying heights are arranged within the cavity. The upper end of each vertical plate is connected to the conical perforated plate, and the lower end of each vertical plate is connected to a corresponding cavity bottom plate. The left and right ends of the vertical plates and the left and right ends of the cavity bottom plates abut against the side plates. The multiple vertical plates, the multiple cavity bottom plates connected to them, together with the side plates, the lower base plate, and the conical perforated plate, divide the receiving cavity into multiple independent cavity units. The multiple conical perforated plate units are arranged in a one-to-one correspondence with the multiple independent cavity units.

[0008] In some embodiments of this application, the cone-shaped perforation is a frustum structure with an upper end face area smaller than the lower end face area.

[0009] In some embodiments of this application, the four side panels are formed by seamlessly pasting the first side panel, the second side panel, the third side panel, and the fourth side panel end to end to form a square frame structure, which is used to position and support the upright panel and the bottom plate.

[0010] In some embodiments of this application, multiple vertical plates of different heights are distributed in a gradient within the receiving cavity.

[0011] In some embodiments of this application, the plurality of conical perforated plate units include a first conical perforated plate unit, a second conical perforated plate unit, a third conical perforated plate unit, a fourth conical perforated plate unit, and a fifth conical perforated plate unit; each conical perforated plate unit is provided with a plurality of identical or different conical perforations.

[0012] In some embodiments of this application, the shell is a cube or cubic structure; the plurality of uprights are four, namely a first upright, a second upright, a third upright, and a fourth upright, which are distributed at intervals and decrease in height; the receiving cavity is divided into five independent cavities, which are filled with air.

[0013] In some embodiments of this application, each conical perforated plate unit of the conical perforated plate corresponds sequentially to each cavity unit of the gradient cavity assembly, and the two together constitute the conical perforated plate cavity sound-absorbing unit.

[0014] In some embodiments of this application, the diameter of the tapered perforation ranges from 2 to 10 mm, and the depth ranges from 3 to 10 mm.

[0015] In some embodiments of this application, the left and right ends of multiple upright plates and the left and right ends of multiple cavity units are seamlessly attached to the side plates.

[0016] In some embodiments of this application, each upright plate is perpendicular to the cavity bottom plate to which it is connected.

[0017] In some embodiments of this application, the left and right ends of each upright plate are vertically connected to the corresponding side plate; and the cavity bottom plate connected to the upright plate is vertically connected to the corresponding side plate.

[0018] In some embodiments of this application, the bottom plate is embedded in the inner wall surface of the lower ends of four side plates that are connected end to end.

[0019] In some embodiments of this application, the upper end of each upright plate is connected to the tapered perforated plate and is perpendicular to the tapered perforated plate.

[0020] Compared with the prior art, the present invention has at least the following advantages: This invention presents a conical perforated plate-gradient cavity multi-frequency sound absorber. It significantly improves the sound absorption effect of typical low-frequency noise in substations at discrete characteristic frequencies of 100-500Hz. This sound-absorbing structure is simple in design, easy to process, install, and maintain, and its cost is controllable. Through precise control of the conical hole size and optimization of the cavity gradient design, the sound absorption performance at the fundamental frequency can be flexibly adjusted. Under the effective parallel coupling effect of the sound-absorbing units in each conical perforated plate cavity, the proposed conical perforated plate-gradient cavity multi-frequency sound absorber can exhibit highly efficient sound absorption performance at multiple frequencies within a compact space, effectively targeting low-frequency noise. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a tapered perforated plate-gradient cavity multi-frequency sound absorber in some embodiments of this application; Figure 2This is a plan view of a tapered perforated plate-gradient cavity multi-frequency sound absorber according to some embodiments of this application; Figure 3 This is an exploded view of a tapered perforated plate-gradient cavity multi-frequency sound absorber according to some embodiments of this application; Figure 4 This is an internal cross-sectional view of a tapered perforated plate-gradient cavity multi-frequency sound absorber in some embodiments of this application; Figure 5 These are photographs of a sample of a tapered perforated plate-gradient cavity multi-frequency sound absorber according to some embodiments of this application; Figure 6 This is a sound absorption measurement curve of a tapered perforated plate-gradient cavity multi-frequency sound absorber in some embodiments of this application; Figure 7 This is an optimized sound absorption curve of a tapered perforated plate-gradient cavity multi-frequency sound absorber in some embodiments of this application.

[0022] In the figure: 1. Conical perforated plate; 2. Gradient cavity assembly; 11. First conical perforated plate unit; 12. Second conical perforated plate unit; 13. Third conical perforated plate unit; 14. Fourth conical perforated plate unit; 15. Fifth conical perforated plate unit; 21. 21. First cavity unit; 22. Second cavity unit; 23. Third cavity unit; 24. Fourth cavity unit; 25. Fifth cavity unit; 20101. First upright plate; 20102. Second upright plate; 20103. Third upright plate; 20104. Fourth upright plate; 20201. First side plate; 20202. Second side plate; 20203. Third side plate; 20204. Fourth side plate; 20301. First cavity bottom plate; 20302. Second cavity bottom plate; 20303. Third cavity bottom plate; 20304. Fourth cavity bottom plate; 20305. Lower bottom plate. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] The following is a reference to the accompanying drawings in the instruction manual. Figures 1-7 As shown, the technical solutions in the embodiments of this utility model are clearly and completely described.

[0025] like Figures 1 to 5 As shown, this utility model proposes a conical perforated plate-gradient cavity multi-frequency sound absorber, which is composed of two parts: a conical perforated plate 1 and a gradient cavity assembly 2.

[0026] In some embodiments of this application, the tapered perforated plate 1 is a rigid plate composed of multiple tapered perforated plate units, each of which has several sets of identical or different tapered perforations; for example... Figure 2 As shown, the conical perforated plate includes four conical perforated plate units, namely the first conical perforated plate unit 11, the second conical perforated plate unit 12, the third conical perforated plate unit 13, the fourth conical perforated plate unit 14, and the fifth conical perforated plate unit 15.

[0027] In some embodiments of this application, the tapered perforation is a frustum structure, wherein the area of ​​the upper end face of the frustum structure is smaller than the area of ​​the lower end face.

[0028] In some embodiments of this application, the diameter of the tapered perforation ranges from 2 to 10 mm, and the depth ranges from 3 to 10 mm.

[0029] In some embodiments of this application, the gradient cavity assembly 2 includes a housing, which includes a lower base plate 20305 and four end-to-end side plates connecting the lower base plate 20305 and the conical perforated plate. A receiving cavity is formed inside the housing, and multiple vertical plates of different heights are arranged at intervals inside the receiving cavity. The upper end of each vertical plate is connected to the conical perforated plate and is perpendicular to the conical perforated plate and the base plate. The lowermost end of each vertical plate is connected to a corresponding cavity base plate. The left and right ends of the vertical plates and the left and right ends of the cavity base plates abut against the side plates. The multiple vertical plates, the multiple cavity base plates connected to them, together with the side plates, the lower base plate 20305 and the conical perforated plate, divide the receiving cavity into multiple independent cavity units. The multiple conical perforated plate units are arranged one-to-one with the multiple independent cavity units.

[0030] In some embodiments of this application, the plurality of uprights are four, namely a first upright 20101, a second upright 20102, a third upright 20103, and a fourth upright 20104, which are distributed at intervals and decrease in height; the receiving cavity is divided into five independent cavities, namely a first cavity unit, a second cavity unit 22, a third cavity unit 23, a fourth cavity unit 24, and a fifth cavity unit 25, which are distributed in a gradient from the first cavity unit to the fifth cavity unit 25, and each cavity unit is filled with air.

[0031] In some embodiments of this application, the upright plate, side plate, lower bottom plate 20305, and cavity bottom plate are all rigid wall panels, which are seamlessly attached to each other in sequence.

[0032] In some embodiments of this application, the first upright plate 20101, the second upright plate 20102, the third upright plate 20103 and the fourth upright plate 20104 have different heights, but their widths and thicknesses are consistent.

[0033] In some embodiments of this application, the length of the upright plate matches the length of the cavity bottom plate in a plane perpendicular to the perforation axis, and the upright plate and the cavity bottom plate are seamlessly bonded.

[0034] In some embodiments of this application, the first side plate 20201, the second side plate 20202, the third side plate 20203 and the fourth side plate 20204 are seamlessly pasted end to end to form a square frame structure, which facilitates precise positioning and supports the upright plate and the base plate.

[0035] In some embodiments of this application, in the length direction, the first upright plate 20101, the second upright plate 20102, the third upright plate 20103 and the fourth upright plate 20104, as well as the first cavity bottom plate 20301, the second cavity bottom plate 20302, the third cavity bottom plate 20303 and the fourth cavity bottom plate 20304 connected thereto, are all seamlessly attached to two oppositely arranged side plates, such as the second side plate 20202 and the fourth side plate 20204.

[0036] In some embodiments of this application, in the width direction, the end of the first cavity bottom plate 20301 away from the first upright plate 20101 is seamlessly attached to the inner wall of the first side plate 20201; the lower bottom plate 20305 is tightly attached to the lower inner wall of the square frame formed by the four side plates.

[0037] In some embodiments of this application, the lower surface of the tapered perforated plate is seamlessly attached to the upper opening of the gradient cavity assembly 2, and the lower surface of each tapered perforated plate unit is seamlessly attached to the upper opening of the corresponding cavity unit in the gradient cavity assembly 2, thereby forming a tapered perforated plate-gradient cavity multi-frequency sound absorber.

[0038] In some embodiments of this application, the upright plate is perpendicular to the tapered perforated plate; the upright plate is perpendicular to the side plate connected to the upright plate.

[0039] In some embodiments of this application, along the length of the vertical plate, 3-6 tapered perforations are distributed in the tapered perforated plate unit corresponding to each cavity unit.

[0040] In some embodiments of this application, the ratio of the diameter of the upper end face of the tapered perforation to the diameter of the lower end face is preferably 1:1.5-2.

[0041] In some embodiments of this application, the housing is a cuboid or cubic structure.

[0042] Under the effective parallel coupling effect of multiple independent cavity units and the conical perforated plate unit that is sealed to them, the proposed conical perforated plate-gradient cavity multi-frequency sound absorber exhibits reliable multi-frequency resonant sound absorption performance in the low-frequency noise band under compact scale conditions.

[0043] In some embodiments of this application, 3D printing technology was used to fabricate a conical perforated plate-gradient cavity multi-frequency sound absorber with an overall length of 100mm, an overall width of 100mm, and a longitudinal dimension of 80mm using photosensitive resin material. Figure 5 As shown in the figure. In the first conical perforated plate unit 11, the second conical perforated plate unit 12, the third conical perforated plate unit 13, the fourth conical perforated plate unit 14, and the fifth conical perforated plate unit 15, each conical hole has the same size: an upper diameter of 3mm, a lower diameter of 6mm, and a hole depth of 3mm. The depths of the first cavity unit 22, the second cavity unit 23, and the fourth cavity unit 24 are 75mm, 35mm, 20mm, and 13mm, respectively. The sound absorption coefficient curves obtained by measuring the acoustic impedance tube are shown in the figure. Figure 6 As shown in the figure, the test results show that the sound absorption coefficients at discrete frequencies of 100Hz, 200Hz, 300Hz, 400Hz, and 500Hz are 0.81, 0.88, 0.81, 0.80, and 0.72, respectively. The proposed conical perforated plate-gradient cavity multi-frequency sound absorber exhibits good sound absorption performance at multiple frequency points with 100Hz as the fundamental frequency.

[0044] In some embodiments of this application, a particle swarm optimization algorithm is used to optimize the structural parameters of the proposed conical perforated plate-gradient cavity multi-frequency sound absorber, resulting in a set of optimized structural parameters: the overall length of the shell is 100mm, the overall width is 100mm, and the longitudinal dimension is 65mm; the depth of all conical holes is 5mm, wherein the upper diameter of the conical hole in the first conical perforated plate unit 11 is 3mm and the lower diameter is 5mm; the upper diameter of the conical hole in the second conical perforated plate unit 12 is 3mm. The lower diameter of the conical hole in the third conical perforated plate unit 13 is 6mm; the upper diameter of the conical hole in the fourth conical perforated plate unit 14 is 4mm and the lower diameter is 6mm; the upper diameter of the conical hole in the fifth conical perforated plate unit 15 is 4mm and the lower diameter is 8mm; the depths of the first cavity unit, the second cavity unit 22, the third cavity unit 23, and the fourth cavity unit 24 are 60mm, 40mm, 20mm, and 15mm, respectively. The sound absorption coefficient curves obtained based on the analytical model and the numerical model are shown below. Figure 7As shown in the figure. Calculation results show that the optimized conical perforated plate-gradient cavity multi-frequency sound absorber has an absorption coefficient close to 1 at discrete frequencies such as 100Hz, 200Hz, 300Hz, 400Hz, and 500Hz, exhibiting perfect sound absorption performance at multiple fundamental frequencies. Furthermore, the overall longitudinal dimension of this sound absorber is approximately 1 / 49 of the wavelength corresponding to 100Hz, classifying it as a subwavelength compact sound absorption structure.

[0045] The proposed conical perforated plate-gradient cavity multi-frequency sound absorber shows certain application potential in controlling the fundamental frequency noise of substations.

[0046] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A conical perforated plate-gradient cavity multi-frequency sound absorber, characterized in that, The sound absorber consists of two parts: a conical perforated plate and a gradient cavity assembly. The conical perforated plate is a rigid plate, which is composed of multiple conical perforated plate units, and each conical perforated plate unit is provided with several sets of the same or different conical perforations. The gradient cavity assembly includes a housing, which includes a bottom plate and four side plates connected end to end to the bottom plate and a conical perforated plate. A receiving cavity is formed inside the housing, and multiple vertical plates of different heights are arranged at intervals inside the receiving cavity. The upper end of each vertical plate is connected to the conical perforated plate. Each upright plate is connected to a corresponding cavity bottom plate at its lower end; the left and right ends of the upright plate and the left and right ends of the cavity bottom plate abut against the side plate. The multiple upright plates, the multiple cavity bottom plates connected to the upright plates, the side plates, the lower bottom plate, and the conical perforated plate together divide the receiving cavity into multiple independent cavity units; the multiple conical perforated plate units are arranged one-to-one with the multiple independent cavity units.

2. The tapered perforated plate-gradient cavity multi-frequency sound absorber according to claim 1, characterized in that, The four side panels are formed by seamlessly gluing the first, second, third, and fourth side panels together end to end, creating a square frame structure used to position and support the upright panels and the bottom plate.

3. The tapered perforated plate-gradient cavity multi-frequency sound absorber according to claim 1, characterized in that, The multiple conical perforated plate units include a first conical perforated plate unit, a second conical perforated plate unit, a third conical perforated plate unit, a fourth conical perforated plate unit, and a fifth conical perforated plate unit.

4. The tapered perforated plate-gradient cavity multi-frequency sound absorber according to claim 1, characterized in that, The shell is a cube or cubic structure; there are four vertical plates, which are distributed at intervals and decrease in height: the first vertical plate, the second vertical plate, the third vertical plate, and the fourth vertical plate; the receiving cavity is divided into five independent cavities, which are filled with air.

5. The tapered perforated plate-gradient cavity multi-frequency sound absorber according to claim 1, characterized in that, Each conical perforated plate unit corresponds sequentially to each cavity unit of the gradient cavity assembly; each upright plate is perpendicular to the conical perforated plate.

6. The tapered perforated plate-gradient cavity multi-frequency sound absorber according to claim 1, characterized in that, The diameter of the tapered perforation ranges from 2 to 10 mm, and the depth ranges from 3 to 10 mm.

7. The tapered perforated plate-gradient cavity multi-frequency sound absorber according to claim 1, characterized in that, The left and right ends of multiple upright plates and the left and right ends of multiple cavity units are seamlessly attached to the corresponding side plates.

8. The tapered perforated plate-gradient cavity multi-frequency sound absorber according to claim 1, characterized in that, The cone-shaped perforation has the shape of a frustum structure where the area of ​​the upper end face is smaller than the area of ​​the lower end face.

9. A tapered perforated plate-gradient cavity multi-frequency sound absorber according to claim 1, characterized in that, The bottom plate is embedded in the inner wall surface of the lower end of the four side plates that are connected end to end.

10. A tapered perforated plate-gradient cavity multi-frequency sound absorber according to claim 1, characterized in that, Each upright plate is perpendicular to the cavity bottom plate it is connected to; the left and right ends of each upright plate are perpendicularly connected to the corresponding side plates; each cavity bottom plate connected to the upright plate is perpendicularly connected to the corresponding side plate.

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