CN113851101A - Pipeline wide-band noise eliminator - Google Patents

Pipeline wide-band noise eliminator Download PDF

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Publication number
CN113851101A
CN113851101A CN202111078517.9A CN202111078517A CN113851101A CN 113851101 A CN113851101 A CN 113851101A CN 202111078517 A CN202111078517 A CN 202111078517A CN 113851101 A CN113851101 A CN 113851101A
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China
Prior art keywords
sound absorption
cavity
sheet
absorption structure
resonance
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CN202111078517.9A
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Chinese (zh)
Inventor
查国涛
颜猛
傅亮
贺才春
郭福林
周常荣
杨涛
胡金昌
傅荣
王心龙
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Zhuzhou Times New Material Technology Co Ltd
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Zhuzhou Times New Material Technology Co Ltd
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Priority to CN202111078517.9A priority Critical patent/CN113851101A/en
Publication of CN113851101A publication Critical patent/CN113851101A/en
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    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/162—Selection of materials
    • G10K11/168—Plural layers of different materials, e.g. sandwiches
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
    • B32B3/26—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer
    • B32B3/266—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/02—Synthetic macromolecular fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/02—Synthetic macromolecular fibres
    • B32B2262/0292—Polyurethane fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/10—Inorganic fibres
    • B32B2262/101—Glass fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/10—Inorganic fibres
    • B32B2262/108—Rockwool fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2266/00—Composition of foam
    • B32B2266/04—Inorganic
    • B32B2266/045—Metal
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/10—Properties of the layers or laminate having particular acoustical properties
    • B32B2307/102—Insulating

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)

Abstract

The invention provides a pipeline wide-frequency noise elimination device which comprises a pipeline and a noise elimination sheet arranged in the pipeline, wherein the noise elimination sheet comprises a resonance sound absorption structure and a porous material sound absorption structure, the resonance sound absorption structure comprises a perforated panel, a solid back plate and a cavity between the perforated panel and the solid back plate, and the cavity is of a cavity depth changing structure along the length direction of the noise elimination sheet. The cavity structure with the cavity depth changed along the length direction of the silencing sheet is arranged, and the cavity depths in different length directions widen the absorption frequency band, so that the technical problem of narrow sound absorption frequency band is solved; a multilayer resonance sound absorption structure is also arranged, so that the absorption frequency band is further widened; in the limited thickness space of the silencing sheet, the cavity is a novel honeycomb cavity or a grid cavity, so that the sound propagation path is obviously or even exponentially prolonged, the cavity depth is increased, the sound absorption of lower frequency is realized, and the problem of poor sound absorption performance of medium and low frequency is solved; the resonance sound absorption structure is combined with the porous material sound absorption structure to obtain the silencing device with low, medium and high full-frequency-band silencing effects.

Description

Pipeline wide-band noise eliminator
Technical Field
The invention relates to the technical field of pipeline noise reduction, in particular to a pipeline wide-frequency noise elimination device.
Background
At present, the pneumatic noise control in the pipeline is widely realized by adopting a sheet type silencer structure. One of the mainstream technologies of the existing sheet type mufflers is to adopt a porous sound absorption structure, and a large amount of mutually communicated and outwardly open microporous materials, such as felts, glass wool, rock wool, melamine sound absorption cotton, polyurethane sound absorption cotton and the like, are arranged in the sound absorption structure, and generally have a high sound absorption coefficient at medium and high frequencies, but have a poor sound absorption coefficient at low frequencies. The other is to adopt a perforated plate resonance sound absorption structure, based on the Helmholtz resonator principle, a steel plate, an aluminum plate or a non-metal plate and the like are perforated with a certain aperture and perforation rate, and a cavity with a certain depth is reserved behind the steel plate, the aluminum plate or the non-metal plate, and the like, so that a resonance sound absorption structure is formed, when the resonance sound absorption structure works, the resonance effect is formed between the holes of the resonance sound absorption structure and an air layer in the cavity at the rear part of the resonance sound absorption structure, the sound absorption performance is good in a specific frequency band, but the existing resonance sound absorption structure only has good sound absorption performance near the resonance frequency, the frequency selectivity is strong, the sound absorption performance is obviously reduced when the resonance frequency deviates, and the sound absorption frequency band is narrow; in addition, when the sound absorption design frequency is lower, the required cavity depth is larger, and the thickness limit of the sound absorption sheet is often exceeded; therefore, the traditional resonance sound absorption structure cannot meet the requirement of broadband sound absorption.
For fans, compressors and compressor equipment, low-order/low-frequency blade passing noise, high-order/high-frequency blade passing noise and broadband noise exist at the same time, and a traditional porous material sound absorption structure or a traditional perforated plate resonance sound absorption structure is adopted, so that a satisfactory noise reduction effect is often difficult to achieve. Therefore, the research on the corner pipeline broadband noise elimination design method and the novel noise elimination device has important engineering application value.
Noun interpretation of technical terms:
resonant sound absorption: when the frequency of the incident sound wave approaches the natural frequency of the resonator, the air column of the resonator throat produces strong vibrations, during which the sound energy is dissipated by overcoming the frictional resistance.
Acoustic impedance: the ratio of the sound pressure at an area of the acoustic wave's vibration surface to the particle velocity through that area. Typically a complex number with the real part being the acoustic resistivity and the imaginary part being the acoustic reactance.
Sound absorption coefficient: the ratio of the acoustic power absorbed by the interface (surface) or medium, plus the sum of the acoustic power transmitted through the interface, to the incident acoustic power. The quantity characterizing the sound absorption properties of a material or construction is a set of values related to frequency.
And fourthly, perforating a plate: a screening surface of a plate having a regular array of identical holes.
The 4 most relevant prior art patents were analyzed through patent literature search. The first patent document is filed under the application number of 202110331249.0, and the patent name is a diversion noise elimination sheet and a diversion noise elimination method of a bent pipeline, and the patent mainly proposes the shape of the diversion noise elimination sheet, namely: the flow guide silencing piece is in a bent shape matched with the bent pipeline and is streamline from head to tail, regenerative noise generated by impacting airflow on the silencing piece can be effectively reduced, the noise reduction performance of the flow guide silencing piece is improved, the pressure loss of the airflow passing through the flow guide silencing piece is reduced, the aerodynamic performance of the flow guide silencing piece is improved, and the flow guide silencing method for the bent pipeline is also provided: perforated plate + honeycomb cavity resonance sound absorption form. The invention relates to a modular metal resonance sound-absorbing elbow, which belongs to the technical field of building heating and ventilating silencers and has the patent number of 202011308147.9, wherein the patent name of the second patent document is the modular metal resonance sound-absorbing elbow; the metal plate resonance layer is inserted into the first sound absorption material, so that the characteristic of broadband continuous resonance sound attenuation is realized. Patent document No. three, application No. 200920246119.1, entitled super microporous plate noise elimination elbow, relates to a super microporous plate noise elimination elbow in which a super microporous metal plate is provided in a casing at a position spaced apart from the casing circumferential outer wall by a distance. The fourth patent document is application number 201310547427.9, and the name is a silencing elbow, wherein a sound absorption material layer is arranged on the inner wall of a right-angle pipe body, and a first microporous plate and a second microporous plate are respectively arranged in an introduction part and a derivation part of the right-angle pipe body, so that the impact force of airflow is reduced, and the silencing elbow plays a role of a resistance plate; the corner part of the right-angle tube body is provided with a plurality of air deflectors, so that mutual collision between air flows is avoided, and sound energy is converted into heat energy. The above 4 patent documents have disadvantages: firstly, a first patent document and a third patent document adopt a perforated plate resonance sound absorption structure, and although the sound absorption structure has better sound absorption performance near the resonance frequency, the frequency selectivity is strong, the sound absorption frequency band is narrow, and the sound absorption performance at medium and high frequencies is poor; secondly, the second patent document adopts the combination of porous material sound absorption and metal sheet resonance sound absorption, although the metal sheet resonance sound absorption plays a certain middle and low frequency sound absorption role, the initial resonance sound absorption frequency of the technology is still high, and the sound absorption coefficient can only reach 0.2-0.5, so the middle and low frequency sound absorption performance is not good; third, patent document four adopts porous material on the inner wall surface of the pipeline to absorb sound, but the sound absorption area is limited, so the high-frequency sound absorption effect is inferior to that of a sheet type silencer; the microporous plate mainly plays a role in reducing the impact force of airflow and a resistance plate, and does not play a role in reducing noise; the multiple air guide sheets mainly play a role in guiding flow, and sound absorption treatment is not adopted, so that the sound absorption performance of the noise eliminator at low frequency is poor.
In summary, the existing resonance sound absorption structure has the following disadvantages: 1. the sound absorption performance is good only in a specific frequency band, namely the sound absorption frequency band is narrow; 2. in the design process, the lower the sound absorption frequency is, the larger the required cavity depth is, and the thickness of the conventional sound absorption sheet cannot meet the design requirement, so that the sound absorption design of lower frequency is difficult to realize due to the limitation of the thickness of the sound absorption sheet. How to design a novel noise eliminator in especially turning pipeline in the pipeline, effectively widen the noise elimination frequency band, carry out the low frequency sound absorption design on current noise elimination piece structure basis, realize good low, medium, high full frequency channel noise elimination effect especially improves the low frequency channel noise elimination effect, is the technical problem that technical staff in the field need to solve urgently.
Disclosure of Invention
The pipeline wide-frequency noise elimination device is provided with a cavity structure with the cavity depth changed along the length direction of the noise elimination sheet, and the cavity depths in the length direction are different, so that the absorption frequency band is widened, and the technical problem of narrow sound absorption frequency band is solved; furthermore, a multilayer resonance sound absorption structure is arranged, so that the sound absorption area is increased, and the absorption frequency band is further widened; furthermore, in the limited thickness space of the sound-absorbing sheet, the cavity is a novel honeycomb cavity or a grid cavity, so that the sound propagation path is obviously or even exponentially prolonged, the cavity depth is increased, the sound absorption of lower frequency is realized, and the problem of poor sound absorption performance of medium and low frequency is solved; the invention is also combined with a sound absorption structure of a porous material for absorbing medium and high frequency to obtain the silencing device with low, medium and high full frequency band silencing effects.
A pipeline wide-frequency noise elimination device comprises a pipeline and at least one noise elimination sheet arranged in the pipeline, wherein the number of the noise elimination sheets is at least one; the noise reduction sheet comprises a resonance sound absorption structure, the resonance sound absorption structure comprises a perforated panel, a solid back plate and a cavity between the perforated panel and the solid back plate, and the cavity is of a cavity depth-variable structure along the length direction of the noise reduction sheet.
The cavity is set to be a sound absorption structure with variable cavity depth, the cavity depth is different, the frequency absorbed by the holes on the perforated panel is different based on the Helmholtz resonator principle, and each cavity depth can generate specific resonance sound absorption frequency, so that the absorption frequency is widened, and the technical problems of strong frequency selectivity and narrow sound absorption frequency band of the sound absorption sheet in the prior art are solved. The designer obtains a desired sound absorption frequency band by adjusting the plate thickness, the hole diameter, the perforation rate, and the cavity depth of the perforated panel.
Furthermore, part or all of the resonance sound absorption structure is a multilayer resonance sound absorption structure along the thickness direction of the sound absorption sheet, the two layers of resonance sound absorption structures are separated by a perforated middle plate, and micropores for sound absorption are formed in the perforated middle plate; when the part of the resonance sound absorption structure is the multilayer resonance sound absorption structure along the thickness direction of the sound absorption sheet, the rest part is the single-layer resonance sound absorption structure.
The invention further arranges a multilayer resonance sound absorption structure on the noise elimination sheet, which increases the contact area and further widens the absorption frequency band. One part of the resonance sound absorption structure is a multilayer resonance sound absorption structure, and the other part of the resonance sound absorption structure is a single-layer resonance sound absorption structure, or the resonance sound absorption structure is a single-layer resonance sound absorption structure or a multilayer resonance sound absorption structure. When one part of the resonance sound absorption structure is a multilayer resonance sound absorption structure and the other part of the resonance sound absorption structure is a single-layer resonance sound absorption structure, the cavity depth of the single-layer resonance sound absorption structure is deeper than that of the resonance sound absorption structure, the cavity depths of the two structures are different, and the resonance sound absorption structure has a wider sound absorption frequency band after being combined and used.
Furthermore, a porous material sound absorption structure is further arranged in the sound absorption piece and used for absorbing medium and high frequencies, and porous sound absorption materials are filled in the porous material sound absorption structure.
The porous material sound absorption structure generally has a higher sound absorption coefficient at medium and high frequencies, but the sound absorption coefficient at low frequencies is poorer, and in order to realize low, medium and high full-frequency-band noise elimination effect on one noise elimination sheet, the porous material sound absorption structure is combined with the resonance sound absorption structure, and the acoustic structure parameters of the resonance sound absorption structure are designed, so that the resonance sound absorption structure absorbs the low frequency and the medium frequency. Such as: the sound-absorbing sheet is sequentially provided with a single-layer resonance sound-absorbing structure, a double-layer resonance sound-absorbing structure and a porous material sound-absorbing structure along the length direction, wherein the porous material sound-absorbing structure is used for absorbing medium and high frequencies, the single-layer resonance sound-absorbing structure is designed to absorb low frequencies, the double-layer resonance sound-absorbing structure absorbs medium and low frequencies, and the low, medium and high full-frequency-band sound-absorbing effect is realized on one sound-absorbing sheet.
Further, the cavity is a honeycomb cavity, a grid cavity or a cavity.
Further, when the cavity is a grid cavity, the grid cavity is but not limited to "(" shape or "<" shape, wave-shaped bent shape.
When the cavity depth is insufficient, the grid cavity is in a bent shape of but not limited to a shape (or a shape <' >, a wave shape) to increase the cavity depth, and when the cavity depth is sufficient, the grid cavity is in a straight line shape.
The shape of the grid cavity is set, the sound transmission path is increased, and the resonance sound absorption frequency is further reduced, so that the sound absorption sheet realizes sound absorption of lower frequency under the condition of unchanged thickness, and the problem that the initial sound absorption frequency of the traditional perforated plate sound absorption structure is large under the limitation of thickness is solved; namely, on the basis of a cavity depth changing structure, a sound propagation path is increased, the maximum cavity depth is utilized as far as possible, and the sound absorption of lower frequency is realized under the condition of the thickness of the existing silencing sheet.
Further, when the pipeline is a bent pipe, the cavity depth changing structure is as follows: the thickness of the silencing sheet along the airflow direction changes from small to large to small, so that a resonant sound absorption structure with variable cavity depth is formed.
The silencing sheet can be used in a straight pipe, a bent pipe and a straight pipe, is in a shape of a straight surface with equal thickness, and needs to be provided with a cavity depth changing structure in a cavity; a muffler piece for in return bend, muffler piece's shape is the arc, specifically is: the thickness of the air flow direction is changed from small to large to small, so that a cavity depth changing structure is formed, and the cavity depth changing structure does not need to be arranged in the cavity.
Furthermore, the silencing sheet is in a shape that the thickness is gradually increased to be decreased along the airflow direction, and the perforated middle plate is also in a structure with sound absorption holes along the airflow direction.
Further, the sound-absorbing sheet has at least two of a single-layer resonance sound-absorbing structure, a multi-layer resonance sound-absorbing structure and a porous material sound-absorbing structure, and the arrangement positions and the number of the three structures in one sound-absorbing sheet are not limited.
The three structures can be randomly arranged and selected according to the sound absorption target frequency ranges of different use occasions.
Further, when at least two structures of a single-layer resonance sound absorption structure, a multi-layer resonance sound absorption structure and a porous material sound absorption structure are arranged along the length direction of the sound absorption sheet, every two structures are separated by a solid partition plate.
The solid partition plate has a sealing effect, forms a cavity with the solid partition plate, and is used as a reinforcing rib to increase the strength of the silencing sheet. In addition, for the noise reduction sheet applied in practical engineering, an integral metal framework is generally provided to form a supporting bearing structure and an appearance of the whole noise reduction sheet, and then the individual sound absorption structure modules are filled in the lattices of the framework, so that the complete noise reduction sheet and the appearance are formed, and at the moment, a solid partition plate does not need to be additionally arranged.
Furthermore, the porous material sound absorption structure comprises two layers of facing plates, wherein the porous sound absorption material is arranged between the two layers of facing plates, and sound absorption holes are formed in the two layers of facing plates.
The porous sound absorption structure consists of a facing plate and a porous sound absorption material. The two layers of facing plates are designed into perforated facing layers, and porous sound-absorbing materials are filled inside the perforated facing layers, so that the sound-absorbing area can be maximally utilized. The protective panel requires that the perforation rate is more than 20 percent, if the porous material is required to be prevented from escaping, a layer of glass fiber cloth or fiber felt is added on the inner surface of the protective panel; the porous sound absorption material can be glass wool, rock wool, melamine sound absorption cotton, polyurethane sound absorption cotton, felt, foamed aluminum and other porous sound absorption materials with high sound absorption coefficient at medium and high frequencies.
Furthermore, the acoustic structure parameters of the resonance sound absorption structure are designed according to a sound absorption target frequency band, and the optimal acoustic impedance and sound absorption coefficient are realized in a unit area.
The usual design intervals for perforated plates and microperforated plates: the perforated panel and the perforated middle plate can be perforated plates, the plate thickness is within the range of 0.4-3 mm, the hole diameter is within the range of 1-5 mm, and the perforation rate is within the range of 5% -30%; the plate thickness can also be 1mm or less, the aperture can be 1mm or less, and the perforation rate can be in the range of 1-5%.
The pipeline broadband noise elimination device can be widely applied to pneumatic noise control of inlet and outlet pipelines of equipment such as fans, compressors, air compressors, wind tunnels and the like.
The invention has the following beneficial effects:
according to the broadband pipeline noise elimination device, the cavity with the variable cavity depth is arranged along the length direction of the noise elimination sheet, sound enters the cavities with different depths from the sound absorption hole, the cavities with different depths absorb different sound frequencies, the structure with the variable cavity depth widens the sound absorption frequency band, and the technical problems that the existing resonance sound absorption structure only absorbs sound near the resonance frequency and the sound absorption frequency band is narrow are solved. The resonant sound absorption structure is a multilayer sound absorption structure, the layers are separated by a perforated middle plate with sound absorption holes, sound enters the cavity from the sound absorption hole on the outermost layer, the sound is filtered and silenced one layer by one layer, the multilayer resonant sound absorption structure is arranged in the thickness direction of the silencing sheet, more frequencies can be absorbed, and particularly, a part of the single-layer sound absorption structure and a part of the multilayer sound absorption structure are arranged, so that the sound absorption frequency band is wider. The acoustic parameters of the single-layer and multi-layer sound absorption structures are designed, so that the single-layer sound absorption structure absorbs low frequency, the multi-layer sound absorption structure absorbs low and medium frequency, the porous material sound absorption structure absorbs medium and high frequency, and low, medium and high full-frequency-band noise elimination effect is achieved on one noise elimination sheet.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a schematic structural view of a broadband muffler device for a pipeline in an embodiment 1.
Fig. 2 is a schematic structural view of the noise-canceling sheet of embodiment 1.
Fig. 3 is a schematic diagram of a grid chamber.
Fig. 4 is a schematic view of a (grid-shaped cavity.
Fig. 5 is a schematic view of a < shaped grid cavity.
Fig. 6 is a schematic view of a wave-shaped grid cavity.
Fig. 7 is a sound absorption schematic of the muffler device.
Fig. 8 is a schematic structural view of the silencer sheet of embodiment 2.
Fig. 9 is a schematic structural view of the silencer sheet of embodiment 3.
Fig. 10 is a schematic structural view of the silencer sheet of embodiment 4.
Fig. 11 is a schematic structural view of the silencer sheet of example 5.
Fig. 12 is a schematic structural view of the silencer sheet of embodiment 6.
Fig. 13 is a schematic structural view of the silencer sheet of example 7.
The sound absorption structure comprises a pipeline 1, a sound absorption sheet 2, a perforated panel 3, a solid backboard 4, a cavity 5, a front grid cavity 51, a rear grid cavity 52, a perforated middle plate 6, a solid partition plate 7, a protective panel 8, a porous sound absorption material 9, an upstream sound absorption structure A, a midstream sound absorption structure B and a downstream sound absorption structure C.
Detailed Description
The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.
Example 1
Providing a pipeline wide-frequency noise elimination device, as shown in fig. 1 and 2, comprising a pipeline 1 and three noise elimination sheets 2 installed in the pipeline 1, wherein the number of the noise elimination sheets 2 is three; the broadband pipeline silencer is applied to the elbow, the silencing piece 2 comprises a resonance sound absorption structure, the resonance sound absorption structure comprises a perforated panel 3, a solid backboard 4 and a cavity 5 between the perforated panel 3 and the solid backboard 4, and as shown in the figure, the silencing piece 2 is in a shape that the thickness is gradually increased to be decreased along the airflow direction, so that the cavity 5 is in a cavity depth-variable structure along the length direction of the silencing piece 2.
The cavity 5 is a grid cavity, the grid cavity 5 is but not limited to a bent shape (such as a ' shape or a ' < ' shape and a wave shape, and as shown in fig. 3-6, the bent grid cavity increases a sound propagation path.
As shown in fig. 2, the sound-absorbing sheet 2 is provided with a single-layer resonance sound-absorbing structure, a double-layer resonance sound-absorbing structure and a porous sound-absorbing structure along the length direction, which are respectively called an upstream sound-absorbing structure a, a midstream sound-absorbing structure B and a downstream sound-absorbing structure C; wherein, the two layers of the sound absorption structure are separated by a perforated middle plate 6, and the perforated middle plate 6 is provided with sound absorption holes.
The perforated middle plate 6 is a structure with sound absorption holes arranged along the airflow direction.
When three structures, namely a resonance sound absorption structure, a resonance sound absorption structure provided with a perforated middle plate and a porous material sound absorption structure, are arranged along the length direction of the silencing sheet 2, every two structures are separated by a solid partition plate 7.
As shown in fig. 2, the upstream sound absorption structure a is a single-layer resonance sound absorption structure, and is composed of a perforated panel 3, a grid cavity 5 and a solid back plate 4, and a single-layer resonance sound absorption structure with variable cavity depth is adopted, so that the maximum cavity depth is utilized as much as possible, a plurality of resonance sound absorption frequencies from low to high can be realized, and a good broadband sound absorption effect is realized at low frequency. The midstream sound absorption structure B is a double-layer resonance sound absorption structure and comprises a perforated panel 3, a front grid cavity 51, a perforated middle plate 6, a rear grid cavity 52 and a solid back plate 4, and a good broadband sound absorption effect can be realized at medium and low frequency by adopting the double-layer resonance sound absorption structure. The downstream sound absorption structure C is composed of a perforated protective panel 8, a porous sound absorption material 9 and the perforated protective panel 8, the porous sound absorption material 9 is made of glass wool, rock wool, melamine sound absorption cotton, polyurethane sound absorption cotton and the like which have high sound absorption coefficients at medium and high frequencies, and a good broadband sound absorption effect can be achieved at the medium and high frequencies. The upstream sound absorption structure A and the midstream sound absorption structure C are separated and connected through a solid partition plate 7, and the midstream sound absorption structure B and the downstream sound absorption structure C are separated and connected through the solid partition plate 7. The sound absorption principle of the silencer is shown in fig. 7, because each silencing sheet 2 respectively adopts a single-layer perforated plate cavity-variable depth resonance sound absorption structure upstream sound absorption structure A, a double-layer perforated plate resonance sound absorption structure midstream sound absorption structure B and a porous material sound absorption structure downstream sound absorption structure C, each sound absorption structure can play the optimal sound absorption performance in the respective optimal working frequency section, a low-frequency sound absorption structure still has certain contribution at medium and high frequencies, a high-frequency sound absorption structure still has certain contribution at medium and low frequencies, and the sound absorption performance is further improved after superposition. Therefore, compared with the existing noise eliminator, the noise eliminator has full-frequency sound absorption characteristics and has good noise elimination effects at low, medium and high frequencies.
Example 2
As shown in fig. 8, in embodiment 2, based on embodiment 1, the midstream sound absorbing structure B in embodiment 1 is changed to the upstream sound absorbing structure a, and the solid partition 7 between the upstream sound absorbing structure a and the midstream sound absorbing structure B in embodiment 1 is removed, which is beneficial to improving the noise reduction effect of the lowest frequency section.
Example 3
As shown in fig. 9, in embodiment 3, based on embodiment 1, the upstream sound absorbing structure a in embodiment 1 is changed to the midstream sound absorbing structure B, and the solid partition 7 between the upstream sound absorbing structure a and the midstream sound absorbing structure B in embodiment 1 is removed, which is beneficial to improving the noise reduction effect of the midstream sound absorbing structure.
Example 4
As shown in fig. 10, in example 4, based on example 1, the midstream sound absorbing structure B of example 1 is changed into two back-to-back upstream sound absorbing structures a, the back-to-back portions of the two back-to-back upstream sound absorbing structures a are solid back plates 4, and two sides are perforated face plates 3. The sound absorption area is increased, and the noise reduction effect of low frequency is improved.
Example 5
Under the condition that the thickness of the sound-absorbing sheet is sufficient, on the basis of embodiment 1, as shown in fig. 11, the front cavity of the double-layer sound-absorbing structure B in embodiment 1 is changed into a downstream sound-absorbing structure C, the rear cavity is still the middle-layer sound-absorbing structure B, so that sound absorption (medium-high frequency sound absorption) with a porous material as an outer layer and resonance sound absorption (medium-low frequency sound absorption) with a perforated plate with a cavity depth as an inner layer are realized, and thus, sound absorption of low frequency and medium-high frequency is realized simultaneously in the same sound-absorbing area.
Example 6
Under the condition that the thickness of the sound-absorbing sheet is sufficient, on the basis of the embodiment 3, as shown in fig. 12, the front cavity of the double-layer sound-absorbing structure B in the embodiment 3 is changed into a downstream sound-absorbing structure C, the rear cavity is still the middle-layer sound-absorbing structure B, so that the sound absorption of the outer layer made of porous material (middle-high frequency sound absorption) is realized, and the sound absorption of the inner layer made of perforated plates with the cavity depth changed is realized in a resonant mode (middle-low frequency sound absorption), so that the sound absorption of low frequency and middle-high frequency is realized at the same time under the same sound absorption area.
Example 7
Under the condition that the thickness of the noise reduction sheet is sufficient, the whole noise reduction sheet is designed into a front cavity and rear cavity double-layer structure in the thickness direction, as shown in fig. 13, the sound absorption (middle and high frequency sound absorption) is realized by adopting a porous material as an outer layer, and the sound absorption (middle and low frequency sound absorption) is realized by adopting a perforated plate with a variable cavity depth as an inner layer, so that the sound absorption of low frequency and middle and high frequency is realized simultaneously in the same sound absorption area.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. The broadband pipeline noise eliminator comprises a pipeline and at least one noise elimination sheet arranged in the pipeline, wherein the number of the noise elimination sheets is at least one; the structure is characterized in that the silencing piece comprises a resonance sound absorption structure, the resonance sound absorption structure comprises a perforated panel, a solid back plate and a cavity between the perforated panel and the solid back plate, and the cavity is a cavity depth-variable structure along the length direction of the silencing piece.
2. The broadband pipeline muffler device as claimed in claim 1, wherein part or all of the resonant sound absorption structure is a multi-layer resonant sound absorption structure along the thickness direction of the muffler sheet, two layers of resonant sound absorption structures are separated by a perforated middle plate, and the perforated middle plate is provided with micropores for sound absorption; when the part of the resonance sound absorption structure is the multilayer resonance sound absorption structure along the thickness direction of the sound absorption sheet, the rest part is the single-layer resonance sound absorption structure.
3. The broadband pipeline muffler device as defined in claim 1, wherein a porous sound absorption structure is further disposed in the muffler sheet for absorbing medium and high frequencies, and a porous sound absorption material is filled in the porous sound absorption structure.
4. The broadband muffler device of claim 1, wherein the cavity is a honeycomb cavity, a grid cavity, or a cavity.
5. The broadband muffler device for pipes of claim 4, wherein when the cavities are grid cavities, the grid cavities are but not limited to "(" shape or "<" shape, wave-shaped bent shape.
6. The broadband muffler device for pipes according to claim 1, wherein when the pipe is an elbow pipe, the cavity depth structure is: the thickness of the silencing sheet along the airflow direction changes from small to large to small, so that a resonant sound absorption structure with variable cavity depth is formed.
7. The broadband muffler device for pipes as claimed in claim 3, wherein the muffler sheet has at least two of a single-layer resonance sound absorbing structure, a multi-layer resonance sound absorbing structure and a porous material sound absorbing structure, and the arrangement positions and the number of the three structures in one muffler sheet are not limited.
8. The broadband muffler device for pipes of claim 3, wherein when at least two of the three structures of the single-layer resonance sound absorption structure, the multi-layer resonance sound absorption structure and the porous material sound absorption structure are arranged along the length direction of the muffler plate, the two structures are separated by a solid partition plate.
9. The broadband muffler device as claimed in claim 3, wherein the porous sound absorbing structure comprises two facing plates, and the porous sound absorbing material is disposed between the two facing plates, and the two facing plates are both provided with sound absorbing holes.
10. The broadband pipeline muffler device as claimed in any one of claims 1 to 9, wherein the acoustic structure parameters of the resonant sound absorption structure are designed according to a sound absorption target frequency band, so that optimal acoustic impedance and sound absorption coefficient are realized in a unit area.
CN202111078517.9A 2021-09-15 2021-09-15 Pipeline wide-band noise eliminator Pending CN113851101A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111078517.9A CN113851101A (en) 2021-09-15 2021-09-15 Pipeline wide-band noise eliminator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111078517.9A CN113851101A (en) 2021-09-15 2021-09-15 Pipeline wide-band noise eliminator

Publications (1)

Publication Number Publication Date
CN113851101A true CN113851101A (en) 2021-12-28

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111078517.9A Pending CN113851101A (en) 2021-09-15 2021-09-15 Pipeline wide-band noise eliminator

Country Status (1)

Country Link
CN (1) CN113851101A (en)

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