A sound attenuation structure for a pipe

Abstract

The application discloses a sound-absorbing structure for a pipeline, which comprises an upper partition plate, a lower partition plate, a left inclined plate, a right inclined plate and an outer circumferential panel and encloses a columnar cavity with a fan ring cross section; further comprising an intermediate plate, the outer radius of the intermediate plate is smaller than that of the upper partition plate and the lower partition plate, and the columnar cavity is divided into a first cavity and a second cavity which are in communication with each other; the first cavity is formed with a first arc-shaped partition plate, a second arc-shaped partition plate and a third arc-shaped partition plate which are arranged at intervals in the second cavity, the third arc-shaped partition plate is arranged at the inner circumferential surface of the second cavity, the first inlet is formed at the inner circumferential surface of the first cavity; the second inlet is formed between the third arc-shaped partition plate at the inner circumferential surface of the second cavity and the left inclined plate. The sound-absorbing structure for the pipeline is adjusted to realize sound absorption of different frequency noises. Meanwhile, the space utilization rate can be improved, the size can be reduced, and the processing difficulty can be reduced to realize high-efficiency sound absorption of the 50-1000 Hz frequency band.

Description

Technical Field

[0001] This invention belongs to the field of acoustic technology, specifically relating to a noise reduction structure for pipelines. Background Technology

[0002] With technological advancements, the speeds of numerous electromechanical devices, automobiles, high-speed trains, and airplanes have increased dramatically, making noise pollution a major concern. Low-frequency noise below 1000Hz presents a significant challenge for noise control. Traditional noise reduction materials, such as foam boards, fiber materials, rubber-plastic boards, slag wool, and micro-perforated boards, often have low sound absorption coefficients in low-frequency applications, requiring substantial weight to achieve effective noise reduction. Acoustic metamaterials, as artificial structural composite materials, combine the advantages of lightweight construction and superior acoustic performance, showing potential for engineering applications in industrial noise reduction and automotive fields.

[0003] Noise reduction in pipeline systems mainly relies on the installation of silencers, which can be divided into reactive silencers and resistive silencers. Traditional pipeline silencer designs still have some shortcomings. For example, reactive silencers require a large space to effectively control low-frequency noise and have a narrow noise reduction bandwidth. Resistive composite silencers are mainly used to control mid-to-high frequency noise, and their low-frequency noise attenuation capability is poor.

[0004] This invention proposes a noise reduction structure suitable for pipeline systems. Through subwavelength-scale microstructure design (i.e., structural dimensions much smaller than the wavelength of sound wave propagation), it achieves sound wave modulation and generates extraordinary physical effects. These extraordinary physical effects can be applied in pipeline noise control. The pipeline silencer formed by this noise reduction structure has the characteristics of small size and excellent sound absorption performance, and has significant application prospects in pipeline noise reduction fields such as automobiles, high-speed rail, industrial noise reduction, and architectural acoustics. Summary of the Invention

[0005] The technical solution provided by this invention to solve its technical problem is as follows:

[0006] A noise reduction structure for pipelines, comprising:

[0007] An upper partition and a lower partition of equal size in the shape of a fan ring are arranged in parallel and spaced apart.

[0008] A left inclined plate, a right inclined plate, and an outer circumferential panel are connected to the upper partition and the lower partition. The left inclined plate, the right inclined plate, and the outer circumferential panel are all perpendicular to the upper partition and the lower partition. The left inclined plate and the right inclined plate extend along the radial direction of the fan ring, and the outer circumferential panel extends along the outer circumferential surface of the fan ring.

[0009] The upper partition, lower partition, left inclined plate, right inclined plate and outer circumferential panel together enclose a columnar cavity with a fan-shaped cross-section;

[0010] It also includes a ring-shaped intermediate plate, the outer radius of which is smaller than the outer radii of the upper and lower partitions. The intermediate plate is located between the upper and lower partitions and is parallel to the upper and lower partitions. The intermediate plate divides the columnar cavity into a first cavity and a second cavity that are interconnected.

[0011] Within the second cavity, a first arc-shaped partition, a second arc-shaped partition, and a third arc-shaped partition are concentrically arranged. The first, second, and third arc-shaped partitions are radially spaced apart and arranged sequentially from the outside to the inside. The third arc-shaped partition is located on the inner circumferential surface of the second cavity, and one side of it is fixedly connected to the right inclined plate. One side of the first and second arc-shaped partitions are respectively fixedly connected to the left inclined plate.

[0012] A first air inlet is formed at the inner circumference of the first cavity; a second air inlet is formed between the third arc-shaped partition and the left inclined plate at the inner circumference of the second cavity.

[0013] Preferably, the cross-section of the cylindrical cavity is a fan ring, and the central angle γ of the fan ring is in the range of 10°≤γ≤355°.

[0014] Preferably, the range of the central angle θ corresponding to the arc edge of the third arc-shaped partition is: 0° < θ < γ.

[0015] Preferably, the sound-absorbing structure for the pipeline is integrally formed by 3D printing, or separately injection molded or metal-formed and then bonded together.

[0016] Preferably, the cross-section of the cylindrical cavity is a fan ring, and the inner radius R of the fan ring is in the range of 5mm≤R≤50mm.

[0017] Preferably, the ratio K1 between the outer radius R2 and the inner radius R of the fan ring is in the range of 2 ≤ K1 ≤ 10.

[0018] Preferably, the ratio K2 between the outer radius R2 of the fan ring and the outer radius R3 of the intermediate plate is in the range of 1.1≤K2≤1.6.

[0019] Preferably, the radial distance L1 between the first arc-shaped partition and the second arc-shaped partition is in the range of 20mm≤L1≤40mm;

[0020] The radial distance L2 between the second and third arc-shaped partitions is in the range of 20mm≤L1≤40mm;

[0021] Preferably, the radial thickness T1 of the first arc-shaped partition is in the range of: 1mm≤T1≤5mm;

[0022] The radial thickness T2 of the second arc-shaped partition is in the range of 1mm≤T2≤5mm;

[0023] The radial thickness T3 of the third arc-shaped partition is in the range of 1mm≤T3≤5mm.

[0024] Preferably, the range of the angle β between the radius of the side of the second arc-shaped partition away from the left inclined plate and the right inclined plate is: 0°≤β<γ.

[0025] Preferably, the dimensions of the first, second, and third arc-shaped partitions along the height direction of the columnar cavity are B1, and the range is: 5mm≤B1≤15mm.

[0026] Preferably, the dimension of the intermediate plate in the height direction of the columnar cavity is B2, and the range is: 1mm≤B2≤3mm.

[0027] Preferably, the distance between the left inclined plate and the middle plate is B3, with a range of 10mm ≤ B3 ≤ 20mm.

[0028] Another technical solution provided by the present invention to solve its technical problem is as follows:

[0029] A noise reduction structure for pipelines, comprising:

[0030] An upper partition and a lower partition of equal size in the shape of a fan ring are arranged in parallel and spaced apart.

[0031] A first left inclined plate, a first right inclined plate, and an outer circumferential panel are connected to the upper partition and the lower partition. The first left inclined plate, the first right inclined plate, and the outer circumferential panel are all perpendicular to the upper partition and the lower partition. The first left inclined plate and the first right inclined plate extend along the radial direction of the fan ring, and the outer circumferential panel extends along the outer circumferential surface of the fan ring. The first left inclined plate is recessed along the radial direction of the fan ring to form a first recessed portion, and the first right inclined plate is recessed along the radial direction of the fan ring to form a second recessed portion.

[0032] It also includes an intermediate sleeve plate connecting the first left inclined plate and the first right inclined plate, one end of the intermediate sleeve plate being connected to the edge of the first recess, and the other end of the intermediate sleeve plate being disposed with the edge of the second recess;

[0033] The upper partition, lower partition, first left inclined plate, first right inclined plate, middle fitting plate and outer circumferential panel together enclose and form a third cavity and a fourth cavity that are interconnected, with the third cavity located above the fourth cavity;

[0034] Within the fourth cavity, a first arc-shaped partition, a second arc-shaped partition, and a third arc-shaped partition are concentrically arranged. The first, second, and third arc-shaped partitions are radially spaced apart and arranged sequentially from the outside to the inside. The third arc-shaped partition is located on the inner circumferential surface of the fourth cavity, and one side of it is fixedly connected to the first right inclined plate. One side of the first and second arc-shaped partitions are respectively fixedly connected to the first left inclined plate.

[0035] A first air inlet is formed at the inner circumference of the third cavity; a second air inlet is formed between the third arc-shaped partition and the first left inclined plate at the inner circumference of the fourth cavity.

[0036] Preferably, the first recess and the second recess are equal in size and have the same shape.

[0037] Preferably, the first recess is a groove.

[0038] Preferably, the cross-section of the third cavity is a first fan ring, and the cross-section of the fourth cavity is a second fan ring. The first fan ring and the second fan ring have the same shape and are equal in size. The central angle γ2 of the second fan ring is in the range of 10°≤γ2≤355°.

[0039] Preferably, the range of the central angle θ corresponding to the arc edge of the third arc-shaped partition is: 0°<θ2<γ2.

[0040] Preferably, the intermediate sleeve plate has an outer circumferential surface concentric with the fan ring, the radius of the outer circumferential surface of the sleeve plate is R4, and the ratio K3 between the outer radius of the second fan ring and the radius R4 of the outer circumferential surface of the sleeve plate is in the range of 1.1≤K3≤1.6.

[0041] Preferably, the angle β2 between the line connecting the center of the second fan ring and the end of the second arc-shaped partition away from the first left inclined plate and the first right inclined plate is in the range of: 0°≤β2<γ2.

[0042] The beneficial effects of this invention are as follows:

[0043] Compared with the prior art, the present invention has the following advantages:

[0044] (1) The present invention uses arc-shaped partitions for spatial arrangement, which improves the low-frequency broadband sound absorption performance of the unit group and reduces the complexity of the sound-absorbing structure.

[0045] (2) The present invention adopts a standardized size design, which makes the overall structure of the noise reduction structure simple and can be mass-produced in a non-3D printing manner. Attached Figure Description

[0046] Figure 1This is an example diagram of a noise-reducing structure for a pipeline arranged on the pipeline, according to this invention application;

[0047] Figure 2 for Figure 1 A schematic diagram of the first embodiment of the noise-reducing structure for pipelines shown;

[0048] Figure 3 for Figure 2 The silencing structure for the pipeline shown is a cross-sectional view along the EE section.

[0049] Figure 4 for Figure 1 A schematic diagram of the second embodiment of the noise-reducing structure for pipelines shown;

[0050] Figure 5 for Figure 4 The silencing structure for the pipeline shown is a cross-sectional view along section FF;

[0051] Figure 6 for Figure 1 The schematic diagram of the third embodiment of the noise-reducing structure for pipelines shown in the figure specifically illustrates the noise-reducing structure for pipelines as follows: Figure 2 Cross-sectional view along the EE section line;

[0052] Figure 7 The transmission loss of the noise-reducing structure used in the pipeline under the first embodiment;

[0053] Figure 8 The transmission loss of the noise reduction structure used in the pipeline under the second embodiment;

[0054] Figure 9 The transmission loss of the noise reduction structure used in the pipeline under the third embodiment;

[0055] Figure 10 for Figure 1 The diagram shows another type of noise reduction structure for pipelines.

[0056] Figure label:

[0057] 100-Pipe; 10-Silencer structure for pipeline; 1-Upper partition; 11-First air inlet; 12-Second air inlet; 2-Lower partition; 3-Left inclined plate; 4-Right inclined plate; 5-Outer circumferential panel; 6-Intermediate plate; 7-First arc-shaped partition; 8-Second arc-shaped partition; 9-Third arc-shaped partition; 20-Silencer structure for pipeline; 21-Upper partition; 22-Lower partition; 23-First left inclined plate; 231-First recess; 24-First right inclined plate; 241-Second recess; 25-Outer circumferential panel; 26-Intermediate fitting plate; 29-Third arc-shaped partition; S1-First cavity; S2-Second cavity. Detailed Implementation

[0058] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0059] Please see Figures 1 to 6 As shown, this invention proposes a noise-reducing structure 10 for pipeline systems, arranged radially along the pipeline 100. It comprises an upper partition 1, a lower partition 2, a left inclined plate 3, a right inclined plate 4, and an outer circumferential panel 5, collectively enclosing a cylindrical cavity with a fan-shaped cross-section. The upper partition 1 and lower partition 2 are parallel and spaced apart, and are fan-shaped and equal in size. The left inclined plate 3, right inclined plate 4, and outer circumferential panel 5 are perpendicular to the upper partition 1 and lower partition 2. The left inclined plate 3 and right inclined plate 4 extend radially along the fan-shaped ring, and the outer circumferential panel 5 extends along the outer circumferential surface of the fan-shaped ring. In this application, the upper partition 1 and lower partition 2 are respectively connected to the left inclined plate 3, right inclined plate 4, and outer circumferential panel 5 to collectively enclose the cylindrical cavity.

[0060] Specifically, the cylindrical cavity also includes an annular intermediate plate 6. The outer radius R3 of the intermediate plate 6 is smaller than the outer radii of the upper partition 1 and the lower partition 2. The intermediate plate 6 is located between the upper partition 1 and the lower partition 2 and is arranged parallel to the upper partition 1 and the lower partition 2 to divide the cylindrical cavity into a first cavity S1 and a second cavity S2 that are interconnected. A first arc-shaped partition 7, a second arc-shaped partition 8, and a third arc-shaped partition 9 are concentrically arranged within the second cavity S2. The first arc-shaped partition 7, the second arc-shaped partition 8, and the third arc-shaped partition 9 are radially spaced apart and arranged sequentially from the outside to the inside. The third arc-shaped partition 9 is located on the inner circumferential surface of the second cavity S2, with one side fixedly connected to the right inclined plate 4, and forming a second air inlet 12 on the inner circumferential surface of the second cavity between it and the left inclined plate 3. One side of the first arc-shaped partition 7 and the second arc-shaped partition 8 are fixedly connected to the left inclined plate 3, and their other sides are preferably not in contact with the right inclined plate 4. The first arc-shaped partition 7, the second arc-shaped partition 8, and the third arc-shaped partition 9 are all fixedly connected to the intermediate plate 6 and the lower partition 2 along the height direction of the columnar cavity. In this application, a first air inlet 11 is formed on the inner circumferential surface of the first cavity S1. Air enters the columnar cavity through the first air inlet 11 and the second air inlet 12 to achieve a noise reduction effect.

[0061] In other embodiments of this example, the other side of the first arc-shaped partition 7 or the second arc-shaped partition 8 may also be in contact with the right inclined plate 4, so that the first cavity S1 and the second cavity S2 that are connected to each other are separated by the first arc-shaped partition 7 or the second arc-shaped partition 8, so that the first air inlet 11 connects the first cavity S1 and part of the second cavity S2 to form a silencing chamber, and the second air inlet 12 connects part of the second cavity S2 to form another silencing chamber, so as to achieve the effect of silencing respectively.

[0062] In this embodiment, the following parameter ranges are selected for the silencing structure 10 used in the pipeline according to this application:

[0063] The cross-section of the cylindrical cavity is a fan-shaped ring, that is, the cross-section of the second cavity S2 is also a fan-shaped ring, as shown below. Figure 3 As shown. The preferred range of the central angle γ of the fan ring is: 10°≤γ≤355°; the preferred range of the central angle θ corresponding to the arc edge of the third arc-shaped partition 9 is: 0°<θ<γ; the preferred range of the angle β between the radius of the side of the second arc-shaped partition 8 away from the left inclined plate 3 and the right inclined plate 4 is: 0°≤β<γ; the preferred range of the angle α between the radius of the side of the first arc-shaped partition 7 away from the left inclined plate 3 and the right inclined plate 4 is: 0°≤α<γ; the preferred range of the inner radius R of the fan ring is: 5mm≤R≤50mm; the range of the ratio K1 between the outer radius R2 of the fan ring and the inner radius R of the fan ring is: 2≤K1≤10; and the range of the ratio K2 between the outer radius R2 of the fan ring and the outer radius R3 of the intermediate plate is: 1.1≤K2≤1.6.

[0064] The dimensions of the first arc-shaped partition 7, the second arc-shaped partition 8, and the third arc-shaped partition 9 along the height direction of the columnar cavity are B1, with a preferred range of 5mm ≤ B1 ≤ 15mm. The dimension of the intermediate plate 6 along the height direction of the columnar cavity is B2, with a preferred range of 1mm ≤ B2 ≤ 3mm. The distance between the left inclined plate 1 and the intermediate plate is B3, preferably 10mm ≤ B3 ≤ 20mm. The radial thickness of the first arc-shaped partition 7 is T1, with a preferred range of 1... The radial thickness of the second arc-shaped partition 8 is T2, with a preferred range of 1mm ≤ T2 ≤ 5mm. The radial thickness of the third arc-shaped partition 9 is T3, with a preferred range of 1mm ≤ T3 ≤ 5mm. The radial distance L1 between the first arc-shaped partition 7 and the second arc-shaped partition 8 is in the range of 20mm ≤ L1 ≤ 40mm. The radial distance L2 between the second arc-shaped partition 8 and the third arc-shaped partition 9 is in the range of 20mm ≤ L2 ≤ 40mm. In this application, the size of the second air inlet 12 along the radial direction of the fan ring is controlled by the central angle θ corresponding to the arc edge of the third arc-shaped partition 9.

[0065] In this embodiment, the silencing structure 10 for pipelines is arranged radially along the pipeline 100 in actual application. By adjusting the above parameters, the sound absorption performance of the silencing structure 10 for pipelines of different sizes can be achieved. By reasonably controlling the parameters, wide-bandwidth sound absorption can be achieved, and single-frequency or multi-frequency sound absorption can be achieved according to the frequency of silencing.

[0066] In this embodiment, the performance of the silencing structure 10 for pipelines is determined by the columnar cavity and the dimensional parameters of the first air inlet 11, the second air inlet 12, and the first arc-shaped partition 7, the second arc-shaped partition 8, and the third arc-shaped partition 9. Therefore, the selection of the substrate does not affect the sound absorption performance of the silencing structure 10 for pipelines. Thus, the selection range of the substrate is wide, and it can be a metal substrate or a non-metal substrate, such as one or more of FR4 epoxy resin, ABS resin, plexiglass, and aluminum. In this application, the silencing structure for pipelines can be processed and formed by 3D printing or injection molding, or by metal forming, and then bonded together.

[0067] To simplify the manufacturing process, generally only angles θ, γ, and β, radius R, dimensions B1, B2, and B3 need to be adjusted for parametric analysis, while other parameters remain fixed. In special cases, angles θ, γ, and β, radius R, radius R2, radius R3, dimensions B1, B2, and B3, thickness T1, thickness T2, thickness T3, distance L1, and distance L2 can all be adjusted.

[0068] In the first embodiment of this application, for example: angle θ=30°, angle γ=45°, angle β=30°, distance L1=30mm, distance L2=30mm, thickness T1=2mm, thickness T2=2mm, thickness T3=5mm, radius R=25mm, radius R2=120mm, radius R=108mm, dimension B1=10mm, dimension B2=2mm, dimension B3=15mm, the noise reduction structure 10 used for pipelines is as follows. Figure 2 or Figure 3 As shown, its transmission loss is calculated through simulation, such as Figure 7 As shown, under the above-mentioned parameter limitations, the sound absorption structure 10 for pipelines has a better sound absorption frequency range in the 505Hz to 565Hz frequency band, where the transmission loss is above 10dB; and the best effect is in the 520Hz to 540Hz frequency band, where the transmission loss is above 20dB.

[0069] In the second embodiment of this application, for example: angle θ=30°, angle γ=355°, angle β=30°, distance L1=30mm, distance L2=30mm, thickness T1=2mm, thickness T2=2mm, thickness T3=1mm, radius R=25mm, radius R2=120mm, radius R=108mm, dimension B1=10mm, dimension B2=2mm, dimension B3=15mm, the noise reduction structure 10 used for pipelines is as follows. Figure 4 or Figure 5 As shown, its transmission loss is calculated through simulation, such as Figure 8 As shown, under the above-mentioned parameters, the sound absorption frequency range of the silencing structure 10 for pipelines is better in the 180Hz to 195Hz, 360Hz to 480Hz, 500Hz to 610Hz, 620Hz to 710Hz, and 955Hz to 970Hz frequency ranges, where the transmission loss is above 10dB; the effect is best in the 450Hz to 480Hz and 515Hz to 570Hz frequency ranges, where the transmission loss is above 20dB. In this application, the left inclined plate 3 and the right inclined plate 4 are integrally formed, but this application is not limited thereto.

[0070] In the third embodiment of this application, for example: angle θ=30°, angle γ=45°, angle β=30°, distance L1=30mm, distance L2=30mm, thickness T1=2mm, thickness T2=2mm, thickness T3=1mm, radius R=25mm, radius R2=120mm, radius R=108mm, dimension B1=10mm, dimension B2=2mm, dimension B3=15mm, its noise reduction structure 10 for pipelines is as follows. Figure 6 As shown, its transmission loss is calculated through simulation, such as Figure 9 As shown, under the above-mentioned parameter limitations, the sound absorption frequency range of the silencing structure 10 used for pipelines is better in the frequency range of 530Hz to 595Hz, where the transmission loss is above 10dB; and it is best in the frequency range of 550Hz to 570Hz, where the transmission loss is above 20dB.

[0071] In other embodiments of this application, in order to achieve the goal of a transmission loss of 30dB in each frequency band, multiple noise reduction structures 10 selected by the present invention for pipelines can be periodically arranged according to a certain structure.

[0072] Please see Figure 10As shown, this invention presents another noise-reducing structure 20 for pipeline systems, arranged along the radial direction of the pipeline 100. It includes an upper baffle 21, a lower baffle 22, a first left inclined plate 23, a first right inclined plate 24, an outer circumferential panel, and an intermediate fitting plate 26, all of equal size and in the shape of a fan ring. The upper baffle 21 and lower baffle 22 are arranged parallel to each other. The first left inclined plate 23, the first right inclined plate 24, and the outer circumferential panel 25 are all connected to the upper baffle 21 and lower baffle 22 respectively in the vertical direction. The first left inclined plate 23, the first right inclined plate 24, and the outer circumferential panel 25 are all perpendicular to the upper baffle 21 and lower baffle 22. The first left inclined plate 23 and the first right inclined plate 24 extend along the radial direction of the fan ring, and the outer circumferential panel 25 extends along the outer circumferential surface of the fan ring. The first left inclined plate 23 is recessed in the radial direction of the fan ring to form a first recess 231, and the first right inclined plate 24 is recessed in the radial direction of the fan ring to form a second recess 241. The intermediate sleeve plate 26 connects the first left inclined plate 23 and the first right inclined plate 24 respectively. One end of the intermediate sleeve plate 26 is connected to the edge of the first recess 231, and the other end is connected to the edge of the second recess 241. The upper partition plate 21, the lower partition plate 22, the first left inclined plate 23, the first right inclined plate 24, the intermediate sleeve plate 26, and the outer circumferential panel 25 together enclose and form a third cavity and a fourth cavity that are interconnected. The third cavity is located above the fourth cavity.

[0073] Specifically, a first arc-shaped partition, a second arc-shaped partition, and a third arc-shaped partition 29 are concentrically arranged within the fourth cavity. These three partitions are radially spaced apart and arranged sequentially from the outside to the inside. The third arc-shaped partition 29 is located on the inner circumferential surface of the fourth cavity, with one side fixedly connected to the first right inclined plate 24. One side of the first and second arc-shaped partitions are respectively fixedly connected to the first left inclined plate 23. The first air inlet is formed at the inner circumference of the third cavity; the second air inlet is formed between the third arc-shaped partition 29 and the first left inclined plate 23 at the inner circumference of the fourth cavity. Air enters the first and second columnar cavities through the first and second air inlets to achieve a noise reduction effect. Preferably, the first recess 231 and the second recess 241 are of equal size and shape, and are located on the same horizontal plane in the vertical direction. The first recess 231 is preferably a groove, but this application is not limited thereto.

[0074] In this embodiment, the central angle γ1 of the first fan ring is in the range of 10°≤γ1≤355°, and the central angle γ2 of the second fan ring is equal to the central angle γ1 of the first fan ring. The outer circumferential surface of the intermediate sleeve plate 26 is concentric with the first fan ring, and the radius of the outer circumferential surface of the sleeve plate is R4. The ratio K3 between the outer radius of the second fan ring and the radius R4 of the outer circumferential surface of the sleeve plate is in the range of 1.1≤K3≤1.6. The central angle θ2 corresponding to the arc edge of the third arc-shaped partition 29 is in the range of 0°<θ2<γ2. The angle β2 between the center of the second fan ring and the end of the second arc-shaped partition away from the first left inclined plate 23 and the first right inclined plate 24 is in the range of 0°≤β2<γ2. In this application, the value of the central angle γ2 is equal to the value of the central angle γ1.

[0075] By using the above settings and referring to the specific parameter design of the various embodiments of the first type of silencing structure 10 for pipelines, the technical effects of the above embodiments can be achieved. Therefore, this application will not describe them in detail.

[0076] In summary, the present invention provides a noise reduction structure for pipelines. This noise reduction structure is compact, thin overall, and has excellent processing technology. The pipeline silencer formed by this noise reduction structure can achieve effective sound absorption at a target frequency band or frequency point by changing the dimensional parameters of a single noise reduction structure.

[0077] The above description of the present invention is merely an example, and appropriate adjustments can be made based on the above description. The frequency band in the example is only one application case of this unit cell, and all acoustic metamaterials prepared from this unit cell configuration are within the scope of protection. Any modifications, substitutions, and improvements made within the spirit, principles, and scope of application of the present invention are included within the scope of protection of the claims of the present invention.

Claims

1. A noise reduction structure for pipelines, characterized in that, include: An upper partition and a lower partition of equal size in the shape of a fan ring are arranged in parallel and spaced apart. A left inclined plate, a right inclined plate, and an outer circumferential panel are connected to the upper partition and the lower partition. The left inclined plate, the right inclined plate, and the outer circumferential panel are all perpendicular to the upper partition and the lower partition. The left inclined plate and the right inclined plate extend along the radial direction of the fan ring, and the outer circumferential panel extends along the outer circumferential surface of the fan ring. The upper partition, lower partition, left inclined plate, right inclined plate and outer circumferential panel together enclose a columnar cavity with a fan-shaped cross-section; It also includes a ring-shaped intermediate plate, the outer radius of which is smaller than the outer radii of the upper and lower partitions. The intermediate plate is located between the upper and lower partitions and is parallel to the upper and lower partitions. The intermediate plate divides the columnar cavity into a first cavity and a second cavity that are interconnected. Within the second cavity, a first arc-shaped partition, a second arc-shaped partition, and a third arc-shaped partition are concentrically arranged. The first, second, and third arc-shaped partitions are radially spaced apart and arranged sequentially from the outside to the inside. The third arc-shaped partition is located on the inner circumferential surface of the second cavity, and one side of it is fixedly connected to the right inclined plate. One side of the first and second arc-shaped partitions are respectively fixedly connected to the left inclined plate. A first air inlet is formed at the inner circumference of the first cavity; a second air inlet is formed between the third arc-shaped partition and the left inclined plate at the inner circumference of the second cavity.

2. The noise-reducing structure for pipelines as described in claim 1, characterized in that, The central angle γ of the fan ring is in the range of 10°≤γ≤355°.

3. A noise-reducing structure for pipelines as described in claim 2, characterized in that, The range of the central angle θ corresponding to the arc edge of the third arc-shaped partition is: 0° < θ < γ.

4. A noise reduction structure for pipelines as described in claim 1, characterized in that, The sound-absorbing structure used for pipelines is integrally formed by 3D printing, or separately injection molded or metal-formed and then bonded together.

5. A noise-reducing structure for pipelines as described in claim 1, characterized in that, The range of the inner radius R of the fan ring is: 5mm≤R≤50mm.

6. A noise-reducing structure for pipelines as described in claim 1, characterized in that, The ratio K1 between the outer radius R2 and the inner radius R of the fan ring is in the range of 2 ≤ K1 ≤ 10.

7. A noise reduction structure for pipelines as described in claim 6, characterized in that, The ratio K2 between the outer radius R2 of the fan ring and the outer radius R3 of the intermediate plate is in the range of 1.1≤K2≤1.

6.

8. A noise-reducing structure for pipelines as described in claim 1, characterized in that, The radial distance L1 between the first arc-shaped partition and the second arc-shaped partition is in the range of 20mm≤L1≤40mm; The radial distance L2 between the second and third arc-shaped partitions is in the range of 20mm≤L2≤40mm.

9. A noise-reducing structure for pipelines as described in claim 1, characterized in that, The radial thickness T1 of the first arc-shaped partition is in the range of 1mm≤T1≤5mm; The radial thickness T2 of the second arc-shaped partition is in the range of: 1mm≤T2≤5mm; The radial thickness T3 of the third arc-shaped partition is in the range of 1mm≤T3≤5mm.

10. A noise-reducing structure for pipelines as described in claim 2, characterized in that, The angle β between the line connecting the center of the fan ring and the end of the second arc-shaped partition away from the left inclined plate and the right inclined plate is in the range of: 0°≤β<γ.

11. A noise-reducing structure for pipelines as described in claim 1, characterized in that, The dimensions of the first, second, and third arc-shaped partitions along the height direction of the columnar cavity are B1, and the range is: 5mm≤B1≤15mm.

12. A noise-reducing structure for pipelines as described in claim 1, characterized in that, The dimension of the intermediate plate in the height direction of the columnar cavity is B2, and the range is: 1mm≤B2≤3mm.

13. A noise-reducing structure for pipelines as described in claim 1, characterized in that, The distance between the left inclined plate and the middle plate is B3, and the range is: 10mm≤B3≤20mm.

14. A noise-reducing structure for pipelines, characterized in that, include: An upper partition and a lower partition of equal size in the shape of a fan ring are arranged in parallel and spaced apart. A first left inclined plate, a first right inclined plate, and an outer circumferential panel are connected to the upper partition and the lower partition. The first left inclined plate, the first right inclined plate, and the outer circumferential panel are all perpendicular to the upper partition and the lower partition. The first left inclined plate and the first right inclined plate extend along the radial direction of the fan ring, and the outer circumferential panel extends along the outer circumferential surface of the fan ring. The first left inclined plate is recessed along the radial direction of the fan ring to form a first recessed portion, and the first right inclined plate is recessed along the radial direction of the fan ring to form a second recessed portion. It also includes an intermediate sleeve plate connecting the first left inclined plate and the first right inclined plate, one end of the intermediate sleeve plate being connected to the edge of the first recess, and the other end of the intermediate sleeve plate being connected to the edge of the second recess; The upper partition, lower partition, first left inclined plate, first right inclined plate, middle fitting plate and outer circumferential panel together enclose and form a third cavity and a fourth cavity that are interconnected, with the third cavity located above the fourth cavity; Within the fourth cavity, a first arc-shaped partition, a second arc-shaped partition, and a third arc-shaped partition are concentrically arranged. The first, second, and third arc-shaped partitions are radially spaced apart and arranged sequentially from the outside to the inside. The third arc-shaped partition is located on the inner circumferential surface of the fourth cavity, and one side of it is fixedly connected to the first right inclined plate. One side of the first and second arc-shaped partitions are respectively fixedly connected to the first left inclined plate. A first air inlet is formed at the inner circumference of the third cavity; a second air inlet is formed between the third arc-shaped partition and the first left inclined plate at the inner circumference of the fourth cavity.

15. A noise-reducing structure for pipelines as described in claim 14, characterized in that, The first recess and the second recess are the same size and have the same shape.

16. A noise-reducing structure for pipelines as described in claim 15, characterized in that, The first recess is a groove.

17. A noise-reducing structure for pipelines as described in claim 14, characterized in that, The cross-section of the third cavity is a first fan ring, and the cross-section of the fourth cavity is a second fan ring. The first fan ring and the second fan ring have the same shape and are equal in size. The central angle γ2 of the second fan ring is in the range of 10°≤γ2≤355°.

18. A noise-reducing structure for pipelines as described in claim 17, characterized in that, The range of the central angle θ corresponding to the arc edge of the third arc-shaped partition is: 0°<θ2<γ2.

19. A noise-reducing structure for pipelines as described in claim 17, characterized in that, The intermediate sleeve plate has an outer circumferential surface concentric with the fan ring, the radius of the outer circumferential surface of the sleeve plate is R4, and the ratio K3 between the outer radius of the second fan ring and the radius R4 of the outer circumferential surface of the sleeve plate is in the range of 1.1≤K3≤1.

6.

20. A noise-reducing structure for pipelines as described in claim 17, characterized in that, The angle β2 between the line connecting the center of the second fan ring and the end of the second arc-shaped partition away from the first left inclined plate and the first right inclined plate is in the range of: 0°≤β2<γ2.

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