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OF THE INVENTION
The disclosure relates generally to acoustic attenuation, and more particularly, to a silencer duct having an element having a non-vertical or non-linear elongated shape, and an acoustic absorbing material that has the elongated shape. The acoustic absorbing material may be made of a material being sufficiently rigid to maintain the shape during operation of the industrial machine in which the silencer element is employed.
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 INVENTION
A first aspect of the disclosure provides a silencer duct, comprising: at least one element including a three-dimensional (3D) chamber having a portion that is at least one of non-vertical or non-linear; and an acoustic absorbing member positioned within the portion, the acoustic absorbing member substantially filling the portion and being self-supporting.
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: at least one element including a three-dimensional chamber having a portion that is at least one of non-vertical or non-linear; and an acoustic absorbing member positioned within the portion, the acoustic absorbing member substantially filling the portion and being self-supporting.
The illustrative aspects of the present disclosure are designed to solve the problems herein described and/or other problems not discussed.
BRIEF DESCRIPTION OF THE DRAWINGS
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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:
FIG. 1 shows a schematic view of an illustrative industrial machine employing a silencer duct according to embodiments of the disclosure.
FIG. 2 shows a perspective view of a silencer duct according to embodiments of the disclosure.
FIGS. 3 and 4 show radial cross-sectional views of alternative embodiments of the silencer duct of FIG. 2.
FIG. 5 shows an axial cross-sectional view of an embodiments of the silencer duct of FIG. 2.
FIG. 6 shows an axial cross-sectional view of an alternative embodiments of the silencer duct according to embodiments of the disclosure.
FIG. 7 shows a perspective view of an alternative embodiments of the silencer duct according to embodiments of the disclosure.
FIG. 8 shows a perspective view of a silencer duct according to another embodiment of the disclosure.
FIGS. 9 and 10 show radial cross-sectional views of alternative embodiments of the silencer duct of FIG. 8.
FIGS. 11-13 show a side view of various embodiments of perforations for perforated walls of the silencer ducts according to embodiments of the disclosure.
FIGS. 14-16 show various embodiments of an acoustic absorbing member according to the disclosure.
FIG. 17 shows an alternative embodiment of an acoustic absorbing member according to the disclosure.
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.
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OF THE INVENTION
As indicated above, the disclosure provides a silencer duct and a turbomachine inlet including the silencer duct. The silencer duct may have an element having a non-vertical or non-linear elongated shape, and an acoustic absorbing material that has the elongated shape. The acoustic absorbing material may be made of a material having sufficient rigidity to maintain the elongated shape during operation of the industrial machine in which the silencer element is employed.
Referring to the drawings, FIG. 1 depicts an illustrative industrial machine in the form of a turbomachine 10 (e.g., simple cycle gas turbine power generation systems) that may include, among other things, a gas turbine system 12. Gas turbine system 12 may combust liquid or gas fuel, such as natural gas and/or a hydrogen-rich synthetic gas, to generate hot combustion gases to drive gas turbine system 12. Gas turbine system 12 includes an air intake section 16, a compressor 18, a combustor component 20, and a turbine component 22. Turbine component 22 is drivingly coupled to compressor 18 via a shaft 24. In operation, air (e.g., ambient air) enters gas turbine system 12 through a turbomachine inlet or air intake section 16 (indicated by arrow 26) and is pressurized in compressor component 18. Inlet 16 may include an intake frame 17 for forming a working fluid flow therein. As illustrated, intake frame 17 is operatively coupled to compressor 18, which includes at least one stage including a plurality of compressor blades coupled to shaft 24. Rotation of shaft 24 causes a corresponding rotation of the compressor blades, thereby drawing air into compressor 18 via inlet 16 and compressing the air prior to entry into combustor component 20.
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 in which a silencer duct 102 according to embodiments of the invention is employed to reduce the noise.
Referring to FIGS. 2-7 and 8-10, embodiments of a silencer duct 102, 202 according to the disclosure are illustrated. Silencer duct 102, 202 may include a duct body 104, 204. In embodiments illustrated, each duct body 104, 204 has a polygonal cross-section; however, such a cross-section may not be necessary in all instances. As will be described, each duct body 102, 202 has a length that is typically shorter than conventional silencer frames and/or panels. As illustrated in the example in FIGS. 2-6, duct body 104 has a substantially square cross-section, and in the example shown in FIGS. 8-10, duct body 204 has a substantially hexagonal cross-section. As used herein, unless otherwise explained, “substantially” indicates having the stated characteristic for the most part, but perhaps with some small variances, e.g., for structural interconnection to other parts, accommodating adjacent structure, ease of manufacture, etc. Other polygonal cross-sections may also be employed such as but not limited to: triangular, pentagonal, octagonal, etc. Many parts of silencer duct 102, 202 made be made of a plastic, for example, polyvinyl chloride (PVC), polypropylene(PP), polypropylene co-polymer (PPC), polypropylene homo-polymer (PPH), polyethylene (PE), high density polyethylene (HDPE) or any other plastic capable of withstanding the environmental and operational characteristics of the particular frame and/or industrial machine in which the duct is employed. Silencer duct body 102, 202 may be formed by any now known or later developed fashion such as: injection molding, extrusion, or coupling of a number of parts, e.g., using fasteners, welding, etc.
As also shown in FIGS. 2 and 8, silencer duct 102, 202 may also include a first perforated wall 110, 210 extending within duct body 104, 204 and substantially parallel (e.g., no more than 1-3° difference) to an interior surface 112, 212, respectively, of the duct body. Collectively, duct body 104, 204 and first perforated wall 110, 210 create an outer element of silencer duct 102, 202. A first acoustic absorbing material 120, 220 may be positioned between duct body 104, 204 and first perforated wall 110, 210, respectively. Further, as will be described further herein, a silencer element 130, 230 may extend axially through duct body 104, 204, respectively. Each silencer element 130, 230 may extend an entirety or a portion of an axial length of duct body 104, 204. Each silencer element 130, 230 may include a second perforated wall 140, 240, respectively, having a second acoustic absorbing material 150, 250, respectively, adjacent thereto. As will be described in greater detail herein, in one embodiment, where the shape of silencer duct 102 allows, acoustic absorbing materials 120, 150, 220, 250 may include any now known or later developed sound absorbing material such as but not limited to at least one of: foam, mineral wool, rock wool and fiberglass. The foam may be reticulated, or otherwise called open cell foam. First acoustic absorbing material 120, 220 may be identical or different than second acoustic absorbing material 150, 250.
As shown in FIGS. 8-10, in one embodiment, first perforated wall 210 may take the form of an elongated hexagonal body having slightly smaller diameter compared to duct body 204. Here, a space 212 (FIG. 9) is created between duct body 204 and first perforated wall 210 in which first acoustic absorbing material 220 is positioned. Similar arrangements may be formed for duct bodies having different cross-sectional shapes. As shown in FIG. 3, with regard to first perforated wall 110 of duct body 104, in on embodiment, it may be formed in configured in a similar fashion as shown in FIGS. 8-10, i.e., as an elongated square body having slightly smaller diameter compared to duct body 104. Other arrangements may also be possible as described elsewhere herein. Each first perforated wall 110, 210 may be made of the same materials as duct body 104, 204, i.e., a plastic. In any event, first perforated wall 110, 210 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 110, 210 may be made of a metal, e.g., steel, stainless steel, aluminum, etc.
As shown in FIGS. 2, 5 and 6, in one embodiment, silencer duct 102 may include a first, axially curved portion 158 curving from an upstream end 160 to a downstream end 162 thereof such that all of a working fluid flow passing therethough impinges at least a portion of an interior surface thereof. That is, a working fluid, e.g., air, flowing therethrough has no clear line of sight from end 160 to 162 and is therefore incapable of taking a linear path through silencer duct 130. In this fashion, all of a working fluid is exposed to acoustic absorption of first and/or second acoustic absorbing material 120, 150. In the embodiments shown, first portion 158 has been illustrated as an elongated S-shape; other shapes such as sinusoidal (e.g., 2 silencer ducts 102 coupled together) for preventing a linear path are also possible and considered within the scope of the disclosure.
As shown in FIG. 6, in an optional embodiment, silencer duct 102 may also include a second, axially linear portion 164 extending from at least one of downstream end 162 of first, axially curved portion 148 and upstream end 160 of first, axially curved portion 158. As shown, each linear portion 164 may include the same structure as the rest of silencer duct 102 (i.e., duct body, first partition wall, first acoustic absorbing material, silencer element, etc.) Alternatively, linear portion(s) 164 may be simplified. For example, linear portions 164 may include just duct body 104 with no acoustic absorption, or just duct body 104 with first perforated wall 110 and first acoustic absorbing material 120 with silencer element 130 omitted, or one or more portions of silencer element 130 omitted.