SILENCER DUCT HAVING SILENCING ELEMENT EXTENDING THERETHROUGH
A silencer duct that may be part of, for example, a turbomachine inlet may include a duct body. A first perforated wall extends within the duct body and substantially parallel to an interior surface of the duct body. A first acoustic absorbing material may be positioned between the duct body and the first perforated wall. A silencer element may extend axially through the duct body, the silencer element including a second perforated wall having a second acoustic absorbing material adjacent thereto.
The disclosure relates generally to acoustic attenuation, and more particularly, to a silencer duct having a silencing duct body and a silencing element extending therethrough.
Noise reduction systems are used on a large variety of industrial machines such as turbomachines to reduce the acoustic impact to surrounding areas. In gas turbine systems, for example, noise reduction systems may be employed in the turbomachine inlet duct, gas turbine enclosures and barrier walls. Traditionally, to attain the necessary acoustic reduction requirements, silencer panels and acoustically treated walls are used in the noisy areas. One mechanism to reduce acoustic impact is to treat walls with acoustic absorbing material. Another mechanism is to place silencer panels in areas where noise reduction is required, such as a working fluid flow path in an intake system duct to prevent noise escaping.
With regard to ducts, each duct typically includes a frame having a number of silencer panels therein. Each panel typically includes an acoustic absorbing material such as mineral/glass wool positioned by a metal supporting member and surrounded by an enclosure including stainless steel perforated sheets on the sides thereof. The sheets are held together by stainless steel end caps. The stainless steel perforated sheets are typically welded to the supporting members that hold the acoustic absorbing material. The perforated stainless steel sheets hold the acoustic absorbing material intact with the supporting members and propagate the sound waves through the perforations into the acoustic absorbing material. The ducts are also typically made of a metal, such as steel or stainless steel. Use of steel for the ducts and silencer panel enclosures presents a number of challenges. For example, the enclosures are very heavy, and are also difficult and costly to manufacture due to the cost of the material and the need for welding to form the ducts and panels. In addition, the panels must be welded in place to the surrounding metal duct and must be custom fit for a particular sized duct. The frames created with the silencer panels are also typically very large in relative size, and in particular, length.
BRIEF DESCRIPTION OF THE INVENTIONA first aspect of the disclosure provides a silencer duct, comprising: a duct body; a first perforated wall extending within the duct body and substantially parallel to an interior surface of the duct body; a first acoustic absorbing material positioned between the duct body and the first perforated wall; and a silencer element extending axially through the duct body, the silencer element including a second perforated wall having a second acoustic absorbing material adjacent thereto.
A second aspect of the disclosure provides a turbomachine inlet, comprising: an intake frame forming a working fluid flow, the intake frame operatively coupled to a compressor; and a silencer duct positioned within the intake frame, the silencer duct including: a duct body, a first perforated wall extending within the duct body and substantially parallel to an interior surface of the duct body, a first acoustic absorbing material positioned between the duct body and the first perforated wall, and a silencer element extending axially through the duct body, the silencer element including a second perforated wall having a second acoustic absorbing material adjacent thereto.
The illustrative aspects of the present disclosure are designed to solve the problems herein described and/or other problems not discussed.
These and other features of this disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure, in which:
It is noted that the drawings of the disclosure are not to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings.
DETAILED DESCRIPTION OF THE INVENTIONAs indicated above, the disclosure provides a silencer duct and a turbomachine inlet including the silencer duct.
Referring to the drawings,
Combustor component 20 may include one or more combustors. In embodiments, a plurality of combustors are disposed in combustor component 20 at multiple circumferential positions in a generally circular or annular configuration about shaft 24. As compressed air exits compressor component 18 and enters combustor component 20, the compressed air is mixed with fuel for combustion within the combustor(s). For example, the combustor(s) may include one or more fuel nozzles that are configured to inject a fuel-air mixture into the combustor(s) in a suitable ratio for combustion, emissions control, fuel consumption, power output, and so forth. Combustion of the fuel-air mixture generates hot pressurized exhaust gases, which may then be utilized to drive one or more turbine stages (each having a plurality of turbine blades) within the turbine component 22.
In operation, the combustion gases flowing into and through turbine component 22 flow against and between the turbine blades, thereby driving the turbine blades and, thus, shaft 24 into rotation. In turbine component 22, the energy of the combustion gases is converted into work, some of which is used to drive compressor component 18 through rotating shaft 24, with the remainder available for useful work to drive a load such as, but not limited to, an electrical generator 28 for producing electricity, and/or another turbine. It is emphasized that turbomachine 10 is simply illustrative of one application in which a silencer panel and system according to embodiments of the invention may be employed. As air flows through inlet 16, noise is created such that a silencer system 100 and compressor component 18 in which a silencer duct 102 according to embodiments of the invention is employed to reduce the noise.
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Silencer element 130 can also be formed in a number of other shapes and/or with different segments. For example, element 130 may include: a T-shaped portion with an additional segment forming four chamber ducts, or with one single wall forming two chamber ducts 134, or as an X-shape forming four triangular chambers 134. Silencer element 130 can also be formed such that chambers 134 have other shapes and/or sizes. For example, element 130 may be formed with curved radially walls and/or chambers 134 can be made of uneven size. In addition, element 130 need not be formed with axially planar walls. For example, as shown in
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Each second perforated wall 140, 240 may be made of the same materials as duct body 104, 204, i.e., a plastic. In any event, second perforated wall 140, 240 and may be made as a unitary piece, e.g., as an injected molded or extruded part, or in parts coupled together, e.g., by fasteners and/or welds. In an alternative embodiment, wall 140, 240 may be made of a plastic or a metal; in the latter case, e.g., steel, stainless steel, aluminum, etc.
In any of the described embodiments, the various silencer elements 130, 230, etc., may also optionally include an inner support 136, 236 to provide additional support and/or additional separation of acoustic absorbing chambers. For example, as shown only in the embodiments of
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Silencer duct 102, 202 provides a number of advantages over conventional frame with silencer panel configurations. For example, the irregular and streamlined flow paths created by polygon and/or S-shape geometries does not create much resistance to inlet air flow, but provides greater impact on the noise absorption, e.g., in a gas turbine during travel from compressor to outside, due to increased reactive impedance to the acoustical waves. As a result, silencer ducts according to embodiments of the disclosure can be provided in a shorter length compared to conventional systems. Further, due to their plastic materials, the silencer ducts have reduced weight and are easier to handle, have reduced cost, and are easier to fabricate using, e.g., injection molding techniques for at least part of the ducts. The ducts also eliminate extensive welding within conventional support panels and between support panels and supporting members. In addition, the plastic may provide slightly enhanced acoustic performance (e.g., a higher decibel (dB) attenuation of approximately, for example, 2 dB or above overall attenuation). In addition, plastic may allow increased perforation areal opening percentages compared to steel panels for the perforated walls.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiment was chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.
Claims
1. A silencer duct, comprising:
- a duct body;
- a first perforated wall extending within the duct body and substantially parallel to an interior surface of the duct body;
- a first acoustic absorbing material positioned between the duct body and the first perforated wall; and
- a silencer element extending axially through the duct body, the silencer element including a second perforated wall having a second acoustic absorbing material adjacent thereto.
2. The silencer duct of claim 1, wherein at least one of the first and second acoustic absorbing materials includes at least one of: foam, mineral wool, rock wool and fiberglass.
3. The silencer duct of claim 1, wherein at least one of the duct body, the first perforated wall and the second perforated wall is made of plastic.
4. The silencer duct of claim 1, wherein the second perforated wall has a hollow interior, and the second acoustic absorbing material is positioned within the hollow interior; and
- further comprising at least one support rib extending from at least one of the duct body and the first perforated wall to support the second perforated wall.
5. The silencer duct of claim 4, further comprising an inner support axially positioned within the hollow interior, and at least one of the plurality of support ribs couples to the inner support for supporting the silencer element.
6. The silencer duct of claim 1, wherein the duct body has a substantially hexagonal cross-section.
7. The silencer duct of claim 1, wherein the silencer element includes a septum including a plurality of partitioning portions partitioning the duct body into at least two chambers, each partitioning portion including a pair of the second perforated walls having the second acoustic absorbing material positioned therebetween; and
- further comprising an inner support extending between the pairs of the second perforated walls of at least one of the partitioning portions to support the silencer element.
8. The silencer duct of claim 7, wherein each of the second perforated walls couples to the first perforated wall.
9. The silencer duct of claim 7, wherein the silencer duct includes a first, axially curved portion curving from an upstream end to a downstream end thereof such that all of a working fluid flow passing therethrough impinges at least a portion of an interior surface thereof.
10. The silencer duct of claim 9, wherein the first portion has an elongated S-shape.
11. The silencer duct of claim 9, further comprising a second, axially linear portion extending from at least one of the downstream end of the first, axially curved portion and the upstream end of the first, axially curved portion.
12. The silencer duct of claim 8, wherein the silencer element spirals from an upstream end to a downstream end of duct body such that all of a working fluid flow passing therethrough impinges at least a portion of an interior surface thereof.
13. A turbomachine inlet, comprising:
- an intake frame forming a working fluid flow, the intake frame operatively coupled to a compressor; and
- a silencer duct positioned within the intake frame, the silencer duct including: a duct body, a first perforated wall extending within the duct body and substantially parallel to an interior surface of the duct body, a first acoustic absorbing material positioned between the duct body and the first perforated wall, and a silencer element extending axially through the duct body, the silencer element including a second perforated wall having a second acoustic absorbing material adjacent thereto.
14. The turbomachine inlet of claim 13, wherein at least one of the duct body, the first perforated wall and the second perforated wall is made of plastic.
15. The turbomachine inlet of claim 13, wherein the second perforated wall has a hollow interior, the second acoustic absorbing material is positioned within the hollow interior; and
- further comprising a plurality of support webs extending from the duct body to support the second perforated wall.
16. The turbomachine inlet of claim 15, further comprising an inner support axially positioned within the hollow interior, and at least one of the plurality of support webs couples to the inner support for supporting the silencer element.
17. The turbomachine inlet of claim 13, wherein the silencer element includes a septum including a plurality of partitioning portions partitioning the duct body into at least two chambers, each partitioning portion including a pair of the second perforated walls having the second acoustic absorbing material positioned therebetween; and
- further comprising an inner support extending between the pairs of the second perforated walls of at least one of the partitioning portions to support the silencer element.
18. The turbomachine inlet of claim 17, wherein the silencer duct includes a first, axially curved portion curving from an upstream end to a downstream end thereof such that all of a working fluid flow passing therethrough impinges at least a portion of an interior surface thereof.
19. The turbomachine inlet of claim 18, further comprising a second, axially linear portion extending from at least one of the downstream end of the first, axially curved portion and the upstream end of the first, axially curved portion.
20. The turbomachine inlet of claim 17, wherein the silencer element spirals from an upstream end to a downstream end of duct body such that all of a working fluid flow passing therethrough impinges at least a portion of an interior surface thereof.
Type: Application
Filed: Sep 16, 2015
Publication Date: Mar 16, 2017
Inventors: Dinesh Venugopal Setty (Bangalore), Dale Joel Davis (Greenville, SC), Laxmikant Merchant (Bangalore), Valery Ivanovich Ponyavin (Greenville, SC), Hua Zhang (Greer, SC)
Application Number: 14/855,901