JP2006022966A - Damping adding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress combustion vibration of a combustor throughout by a wide range of frequency bands. <P>SOLUTION: A resonance box having a resonance pipe bent like a labyrinth is attached to the combustor. Porous metals are attached to two or more portions of the resonance pipe. The resonance box having the labyrinth like resonance pipe is small, and it resonates with vibration of a low frequency. By the porous metals attached to two or more portions, vibration throughout a wide range of frequency bands is damped. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a combustor for a gas turbine.

  A gas turbine combustor may generate combustion vibrations when fuel is combusted therein. There is a need for a technology that suppresses combustion vibration for stable operation.

  In a loudspeaker having a vibration surface at one end of the waveguide and an opening at the other end, the distance between the vibration suppression body and the opening is greater than the distance between the vibration suppression body and the vibration surface provided in the waveguide. There is known a loudspeaker whose value is significantly large (see Patent Document 1).

In order to suppress combustion vibration of a gas turbine combustor, a vibration suppression device including a pipe and a resistance plate is known (see Patent Document 2).
US Patent US6278789B1 US Pat. No. 5,658,157

An object of the present invention is to provide a gas turbine combustor having a small combustion vibration in a wide frequency band.
Another object of the present invention is to provide an acoustic damper that efficiently reduces combustion vibration of a combustor.
Still another object of the present invention is to provide an acoustic damper that efficiently reduces combustion vibration in a low frequency band (about 30 Hz to 300 Hz).
Still another object of the present invention is to provide an acoustic damper that has a small volume required for installation and that efficiently reduces combustion vibration in a low frequency band (about 30 Hz to 300 Hz).
Still another object of the present invention is to provide an acoustic damper having stable sound absorbing performance against changes in pressure fluctuation.
Still another object of the present invention is to provide a gas turbine combustor that efficiently reduces combustion vibrations in a wide frequency range by using an acoustic liner that efficiently reduces combustion vibrations in a high frequency band and the acoustic damper. It is.

  In the following, means for solving the problem will be described using the numbers used in [Best Mode for Carrying Out the Invention] in parentheses. These numbers are added to clarify the correspondence between the description of [Claims] and [Best Mode for Carrying Out the Invention]. However, these numbers should not be used to interpret the technical scope of the invention described in [Claims].

  The acoustic damper (10) according to the present invention includes a member (9) that has an opening (21) and forms a folded pipe (39) inside, and a resistor that provides resistance to the fluid flowing through the pipe (39). (37, 38).

  The acoustic damper (10) according to the present invention is a member (9) having a duct (39) having an opening (21) and having at least one refracting part (31) whose direction changes at an angle of 90 degrees or more. ) And resistors (37, 38) that provide resistance to the fluid flowing through the pipe line (39).

  In the acoustic damper (10) according to the present invention, the pipe (39) has a spiral shape.

  In the acoustic damper (10) according to the present invention, the pipe line (39) has a hole (34) that communicates the inside of the pipe line (39) with the inside of the passenger compartment (4) that houses the combustor (2, 7). Have

  In the acoustic damper (10) according to the present invention, the pipe (39) has a square or circular cross section.

The acoustic damper (10) according to the present invention is provided at the corner (31) where the direction of the pipe (39) changes discontinuously, and reduces the change in the width of the pipe (39) at the corner ( 32).
In the acoustic damper (10) according to the present invention, the pipe line (39) has a tapered portion (35) in which the cross-sectional area of the pipe line (39) is larger as it is closer to the opening (21).

  In the acoustic damper (10) according to the present invention, the resistors (37, 38) include a first resistor (37, 38) and a second resistor (37, 38) arranged apart from each other.

  In the acoustic damper (10) according to the present invention, the resistors (37, 38) include a porous metal.

  In the acoustic damper (10) according to the present invention, the porous metal is an alloy containing nickel and chromium, and the porosity is 90% or more.

  In the acoustic damper (10) according to the present invention, the resistors (37, 38) include a metal net.

  In the acoustic damper (10) according to the present invention, the porous metal is fixed to the pipe line (39) by brazing.

  The acoustic damper (10) according to the present invention includes a cassette for holding the resistors (37, 38). The member (9) and the cassette (11) are detachable.

  In the acoustic damper (10) according to the present invention, the acoustic damper (10) is attached to the bent portion (6) of the bypass pipe (7) included in the combustion chamber of the gas turbine. The inside of the bypass pipe (7) and the pipe line (39) communicate with each other through the opening (21).

  The acoustic damper (10) according to the present invention is attached to a bypass pipe (7) coupled in a slidable structure with respect to the combustion cylinder (2).

で示される。 The combustion vibration of the combustor (2) to which the acoustic damper (10) according to the present invention is attached is large in the frequency range indicated by f1 to f2, and the length of the pipe line (39) stores the combustor (2). The temperature of the passenger compartment (4) is indicated by T, and α is a constant between 0.7 and 1.2.

Indicated by

  The gas turbine combustor (2, 7) according to the present invention is provided in a predetermined first range of the combustion cylinder (2) included in the combustor (2, 7), and is in a resonant space between the combustion cylinder (2). A combustion cylinder housing (52) is formed. The inside of the combustion cylinder (2) and the resonance space communicate with each other through a plurality of combustion cylinder through holes (53). The maximum length of the combustion cylinder housing (52) is not less than the diameter of the combustion cylinder (2).

  In the acoustic damper (10) according to the present invention, the acoustic damper (10) is attached to the combustor (2, 7) of the gas turbine. The combustion chamber of the combustor (2, 7) and the pipe line (39) communicate with each other through the opening (21).

  The combustor for a gas turbine (2, 7) according to the present invention comprises an acoustic damper (10) according to the present invention.

  The gas turbine according to the present invention includes the gas turbine combustor (2, 7) according to the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the combustor for gas turbines with a small combustion vibration in a wide frequency band is provided.
Furthermore, according to this invention, the acoustic damper which reduces the combustion vibration of a combustor efficiently is provided.
Furthermore, according to the present invention, an acoustic damper that efficiently reduces combustion vibrations in a low frequency band (about 30 Hz to 300 Hz) is provided.
Furthermore, according to the present invention, there is provided an acoustic damper that has a small volume required for installation and that efficiently reduces combustion vibration in a low frequency band (about 30 Hz to 300 Hz).
Furthermore, according to the present invention, an acoustic damper is provided in which sound absorption performance is stable with respect to changes in pressure fluctuation.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings. Referring to FIG. 1, a combustor body 2 of a gas turbine is shown. The combustor main body 2 is installed inside a vehicle compartment 4 formed by a vehicle compartment wall 5 fixed to the ground. The combustor body 2 includes a bypass 7 for taking in bypass air. The bypass 7 has a bent bypass elbow 6, and the bypass elbow 6 is connected to a bypass valve 8. The bypass valve 8 is fixed to the passenger compartment wall 5. The bypass valve 8 controls the flow rate of air taken into the combustor body 2 by the bypass 6. An acoustic damper 10 according to the present invention is attached to the bypass elbow 6. An acoustic liner 50 that is long in the circumferential direction is attached to the combustor body 2.

  The acoustic damper 10 has a maze-structured pipeline inside. The expression “maze structure” of a pipeline is a non-straight shape, such as when the pipeline is folded. Compared to the case where the pipeline is straight, the length of the pipeline (resonance by the pipeline) It shows that the size of the portion of the pipeline is small with respect to the wavelength of acoustic vibration to be performed.

  The acoustic damper 10 according to the present invention is provided at a place other than the bypass elbow 6, for example, the outer wall of the combustion region of the combustor body 2 (the position where the acoustic liner 50 is installed in FIG. 1) or the top hat (upstream of the combustor body 2). Even if it is installed in the vicinity of the inlet where the compressed air is introduced from the vehicle compartment 4 into the combustor body 2, the effect can be obtained. Since the bypass elbow 6 has large combustion vibration, the acoustic damper 10 installed in the bypass elbow 6 has a high effect of suppressing vibration. Furthermore, since the temperature of the outer wall of the bypass elbow 6 is lower than the temperature of the outer wall of the combustion region of the combustor body 2, the degree of freedom in design is increased, for example, the range of materials used for the acoustic damper 10 is widened. . The connecting portion between the acoustic damper 10 and the bypass elbow 6 or the connecting portion between the bypass elbow 6 and the combustor body 2 has a sliding portion to relieve structural distortion caused by thermal expansion during gas turbine operation.

  Referring to FIG. 2, a view of the bypass elbow 6 and the acoustic damper 10 viewed from the direction A in FIG. 1 is shown. The acoustic damper 10 includes a holder 13, a pair of resonance boxes 9, and a pair of cassettes 11. The shape of the pair of resonance boxes 9 is substantially symmetric. The shape of the pair of cassettes 11 is substantially symmetrical. The holder 13 is attached so as to hold the bypass elbow 6. The resonance box 9 is fixed to the holder 13 with a space between it and the bypass elbow 6.

  The cassette 11 is disposed between the bypass elbow 6 and the resonance box 9 and is fixed by a holder 13. The cassette 11 includes a porous metal 37. The surface of the porous metal 37 faces the bypass elbow 6 and the resonance box 9. The outer wall of the bypass elbow 6 facing the porous metal 37 is a porous plate provided with a number of gas inlets 28. The gas inlet 28 has an opening ratio of approximately 50%. The inside of the resonance box 9 has a first layer 22 facing the porous metal 37 and a second layer 24 opposite to the porous metal 37 with respect to the first layer 22.

  The porous metal 37 is a material having a three-dimensional network structure (porous). The porous metal 37 is a metal that does not deteriorate at the temperature of the passenger compartment 4 (about 450 ° C.). For example, a nickel-based alloy containing nickel and preferably containing chromium. More preferably, it is a material having high oxidation resistance and high wear resistance exemplified by Hastelloy-X. The porous metal 37 has a large porosity (volume occupied by pores in the approximate shape with respect to the volume occupied by the approximate shape of the porous metal), for example, preferably 90% or more. Examples of such materials include materials specified by the trade name Celmet of Sumitomo Electric Industries, Ltd.

  The porous metal 37 is preferably fixed to the cassette 11 in order to reduce wear. Furthermore, it is preferable that all the portions where the porous metal 37 is in contact with the metal are joined. Fixing is preferably performed by brazing.

  It is preferable that a metal net is stretched on the inner wall or the outer wall of the bypass elbow 6 in the region where the gas inlet 28 is provided. Instead of the perforated plate, the outer wall of the bypass elbow 6 facing the porous metal 37 may have a structure in which a hole having a diameter of several centimeters or more is provided and a metal net is stretched in the hole.

  On the side surface of the resonance box 9, borescope holes 41 are provided at positions corresponding to the first layer 22 and positions corresponding to the second layer 24. The borescope hole 41 has a diameter capable of introducing equipment such as a borescope for examining the inside of the resonance box 9. Referring to FIG. 3, a perspective view of an operation process for attaching the acoustic damper 10 to the bypass elbow 6 is shown. The cassette 11 is detachably attached to the holder 13 with bolts or the like. Further, a purge hole 34 provided in the outer wall of the second layer 24 of the resonance box 9 is shown.

  Since the cassette 11 can be attached to and detached from the holder 13, it can be easily replaced when the porous metal 37 is deteriorated due to oxidation or the like.

  When the cassette 11 is fixed to the holder 13 or the cassette 11 and the holder 13 have an integral structure, the manufacturing is simple. Whether the cassette 11 and the holder 13 are detachable or fixed is appropriately selected by a designer.

  Referring to FIG. 4, the internal configuration of the resonance box 9 is shown. Referring to FIG. 4A, a cross-sectional view of the first layer 22 taken along the BB ′ axis in FIG. 2 is shown. The first layer 22 forms a spiral duct 39 inside by the partition 30. The cross section of the pipe 39 in the direction perpendicular to the flow direction is a rectangle or a square having a side length of 15 mm to 50 mm. It is preferable that the cross section of the pipe is rectangular or square when a labyrinth structure is formed by the pipe because a gap generated between the pipe and the adjacent pipe is reduced.

  As the resonance box, a resonance box having a snail shape obtained by winding a circular tube in a spiral shape is conceivable. In this case, the shape of the cross section of the pipe line is a circle. Such a resonance box can use an existing circular tube as a material, and is low in cost.

  Line 39 connects to gas inlet 21 at the center of the helix. The conduit 39 has a tapered portion 35 that becomes wider as it is closer to the gas inlet 21. A transfer layer 25 is provided at the end of the pipe 39 of the first layer 22 opposite to the gas inlet 21. The pipe line 39 communicates with the pipe line of the second layer 24 in the layer transfer section 25. A branch pipe (not shown) is provided on the side opposite to the second layer of the layer transfer portion 25.

  The pipe line 39 has a corner 31 whose angle changes abruptly as compared with other parts. A fender 32 is provided at the corner 31 so that the change in the width of the pipe 39 is small. Without the fender 32, the fender may be present because the pipe width changes abruptly at a corner where the angle changes abruptly, and a relatively large reflection of sound waves occurs there, which may impair the performance of the pipe. preferable.

  An oil drain hole 36 is provided on the outer wall of the resonance box 9. The oil drain hole 36 is provided at a location where the oil easily collects when the oil enters the pipe 36, that is, on the lower side in the vertical direction. In the case where oil easily collects in the duct inside the spiral, it is preferable that an oil drain hole (not shown) is also provided in the partition 30 in that place.

  Referring to FIG. 4B, a sectional view of the second layer 24 taken along the CC ′ axis in FIG. 2 is shown. The second layer 24 forms a spiral duct 39 inside the partition 30.

  A porous metal 38 is installed in a pipe line 39 of the second layer 24 near the layer transfer part 25. The porous metal 38 is formed of the same material as the porous metal 37. The porous metal 38 is fixed to the resonance box 9 by the same method as the method in which the porous metal 37 is fixed to the cassette 11. The opposite end (near the center of the helix) of the conduit 39 of the conduit 39 of the second layer 24 is the conduit end 33. The purge hole 34 shown in FIG. 3 is provided at the pipe end 33. The place where the purge hole 34 is provided may be a place other than the pipe end 33, or a plurality of places may be provided.

  The pipe line 39 of the second layer 24 has a corner 31 whose angle changes abruptly as compared with other parts. A fender 32 is provided at the corner 31 so that the change in the width of the pipe 39 is small. An oil drain hole 36 similar to that of the first layer 22 is provided on the outer wall of the resonance box 9 of the second layer 24.

  Referring to FIG. 5, an example of the corner shape of the partition 30 at the corner 31 is shown. Referring to FIG. 5A, the corner 42a of the partition 30 has a square shape. Referring to FIG. 5 (b), the corner 42b is rounded. The acoustic resistance received at the corner 42b by the fluid flowing through the pipeline is suppressed more than the acoustic resistance received at the corner 42a. Referring to FIG. 5C, a guide 43 is provided at the corner 42c. The acoustic resistance received at the guide 43 by the fluid flowing through the pipeline is further suppressed than the acoustic resistance received at the corner 42b.

  The operation of the combustor to which the acoustic damper 10 having the above configuration is attached will be described below. When the gas turbine is operated, air compressed by a compressor (not shown) is introduced into the passenger compartment 4 and further introduced into the combustor body 2. Fuel is further supplied to the combustor body 2 through a fuel supply pipe (not shown). The mixed gas of fuel and compressed air is ignited by a burner (not shown), and the interior of the combustor body 2 is filled with high-temperature combustion gas. Combustion gas is sent from the combustor body 2 to a turbine (not shown) to drive the turbine.

  In order to adjust the state of combustion inside the combustor body 2, the bypass valve 8 is controlled, and air is introduced into the combustor body 2 from the bypass 7.

  The combustor body 2 and the bypass 7 vibrate due to pressure fluctuations of the combustion gas. The gas inside the bypass elbow 6 enters and exits the resonance box 9 from the gas inlet 21 through the porous metal 37 from the gas inlet 28, and the acoustic energy generated by combustion vibration (acoustic vibration) enters the inside of the resonance box 9. be introduced.

  The inside of the resonance box 9 turns around the spiral duct 39 from the gas inlet 21 in the first layer 22 to reach the layer transfer unit 25, moves to the second layer 24 in the layer transfer unit 25, In the second layer 24, a long pipe line 39 that reaches the pipe terminal end 33 from the layer transfer part 25 to the inner winding direction is provided. Due to this long pipe 39, low-frequency combustion vibrations resonate in the resonance box 9.

In a gas turbine with a cabin temperature T (unit: Kelvin), the length of the pipe line suitable for countermeasures against combustion vibrations with a frequency of f1 to f2 (unit: hertz) is:
α × 40 × T ^ 0.5 / (f1 + f2), (unit: meter),
It is. α is a coefficient for correcting the influence of the bending of the pipe and is a numerical value between 0.7 and 1.2. The length of the pipeline is defined by the length of the center of the pipeline.

  The acoustic damper 10 having a spiral duct has a volume of about 70% smaller than that in the case of using a resonance box having no partition inside. Therefore, the freedom degree of the site | part attached to a combustor becomes large. Further, since the moment of inertia is small, the swing motion associated with combustion vibration is suppressed.

  By providing a branch pipe (not shown) in the resonance box 9, an acoustic vibration having a frequency depending on the length, position, and shape of the branch pipe resonates. Therefore, acoustic vibrations in a wider range of frequencies are suppressed by the acoustic damper 10. By adjusting the length of the branch pipe, it is easy to adjust the acoustic characteristics of the acoustic damper 10 in accordance with the characteristics of the combustor.

  Since the pipe line 39 has the tapered portion 35, the sound of a lower frequency resonates. In other words, the pipeline having the tapered portion 35 can be tuned to the same frequency by a pipeline shorter than the pipeline having no tapered portion. Therefore, the volume of the acoustic damper 10 having the tapered portion 35 is smaller.

  The sound wave reflected by the corner 31 of the pipe line 39 is reduced by the fender 32. By adopting the corner 42b having a small curvature shown in FIG. 5 (b) or the guide 43 shown in FIG. 5 (c) as the structure of the corner 31, the acoustic resistance at the corner 31 is reduced and the reflection of sound waves is reduced. To do.

  In the porous metals 37 and 38, the vibrating gas generates vortices, and the vibration energy is attenuated. In particular, low-frequency vibrations depending on the shape of the resonance box 9 are effectively damped.

  Referring to FIG. 6, a schematic diagram of an acoustic tube including a plurality of porous metals 37 and 38 is shown. Referring to FIG. 6A, the acoustic tube is shown to resonate with acoustic vibration having a wavelength four times the length of the acoustic tube. The node of the acoustic vibration is at the pipe end 33 and the antinode is at the gas inlet 21. Such acoustic vibration is effectively damped by the porous metal 37 disposed at the gas inlet 21. Referring to FIG. 6B, it is shown that the acoustic tube is resonating with acoustic vibration having a wavelength twice that of the acoustic tube. The node of the acoustic vibration is at the gas inlet 21 and the pipe end 33, and the antinode is in the middle between the gas inlet 21 and the pipe end 33. Such acoustic vibrations are effectively damped by the porous metal 38 disposed between the gas inlet 21 and the pipe end 33.

  That is, by adopting a multi-stage structure in which resistors exemplified by porous metal (those that attenuate acoustic vibration) are arranged at a plurality of positions inside the acoustic tube, acoustic vibrations in a wider range of frequencies can be obtained. Attenuates.

  The resistor is not limited to the porous metal, and the vibration of the gas is also attenuated by using a perforated plate (metal plate provided with a large number of through holes by a drill or the like), an orifice, or a metal net. By arranging such metal plates at a plurality of positions of the acoustic tube, acoustic vibrations in a wider range of frequencies are attenuated.

  The perforated plate or orifice changes its acoustic characteristics (performance of attenuating acoustic vibrations of various frequencies) depending on the magnitude of the pressure fluctuation of the gas. Furthermore, when a multistage structure is employed, the effects of the plurality of resistors on the acoustic vibration influence each other. Due to these properties, it is difficult for an acoustic damper having a multistage structure of perforated plates or orifices to predict and design acoustic characteristics (performance of attenuating acoustic vibrations of various frequencies). It is not easy to obtain desirable acoustic characteristics with such an acoustic damper.

When a porous metal is used as the resistor, more stable acoustic characteristics can be obtained with respect to the pressure fluctuation level of the gas. For this reason,
(1) The performance of attenuating acoustic vibration with respect to a small pressure fluctuation level is stable,
(2) It is easy to obtain stable acoustic characteristics over a wide range of pressure fluctuation levels,
(3) It is easy to predict acoustic characteristics at the design stage.
The desired effect is obtained.
That is, an acoustic damper in which a resistor having a multi-stage structure is employed and the resistor is a porous metal can easily obtain a stable damping effect with respect to vibrations in a wide range of frequencies.

  The resistance value representing the ability of the porous metals 37 and 38 to attenuate the gas combustion vibration is adjusted by the porosity or thickness of the porous metals 37 and 38. The arrangement of the plurality of porous metals 37 and 38 having a multistage structure is arranged at a position where desirable acoustic characteristics can be obtained by analysis.

  When the diameter of the gas inlet 28 is large, the contribution to the attenuation of vibration energy is small. In this case, it is easy to predict the acoustic characteristics of the acoustic liner 10 at the design stage, which is preferable.

  When the gas turbine is in operation, the pressure in the passenger compartment 4 is higher than the pressure in the combustor body 2. Therefore, the air in the passenger compartment 4 flows into the conduit 39 through the purge hole 34. By this air flow, the temperature rise of the resonance box 9 is suppressed. Furthermore, when oil enters the inside of the resonance box 9, evaporation of the oil is promoted by the air flow, and liquid oil is prevented from being accumulated in the pipe line 39.

  The resonance box 9 of the acoustic damper 10 in the present embodiment may have a maze structure in which the pipe line 39 is different from the spiral shape. Referring to FIG. 8, the structure of a resonance box 9a in a modification of the present embodiment is shown. The resonance box 9a has at least one corner 31a in which the direction of the pipe line 39a changes by approximately 180 degrees. The resonance box 9a may have a multilayer structure of two or more layers like the spiral resonance box 9. In the resonance box 9a having such a pipe line, it is easy to examine the pipe line 39a by introducing a fiberscope or the like from the borescope hole 41a.

[Sound liner]
The acoustic damper 10 according to the present invention is preferably used with the acoustic liner 50. Referring to FIG. 9, a cutaway perspective view of the acoustic liner 50 is shown. The acoustic liner 50 includes a housing 52 attached to the wall 51 of the combustor body 2. The housing 52 has a side part 57 that contacts the wall surface of the combustor body 2 and a bottom part 54 that contacts the side part 57 and faces the wall of the combustor body 2. The side surface portion 57 has a flat plate portion 56 that is substantially flat and joined to the combustor body 2, and a curved surface portion 58 that connects the flat plate portion 56 and the bottom portion 54. The distance between the bottom 54 and the wall 51 of the combustor body 2 is approximately 10 mm to 30 mm.

  A purge hole 60 is provided in the bottom portion 54. The flat plate portion 56 is provided with a cooling hole 62. A configuration without one of the cooling hole 62 and the purge hole 60 is also possible.

  A large number of holes 53 are provided in the wall 51 in the region where the housing 52 is provided. The diameter of the hole 53 is about 1 mm to 5 mm.

  A heat-resistant coating 64 is applied to the surface of the region where the housing 52 is provided, which faces the combustion region of the combustor body 2. Examples of the material of the heat resistant coating 64 include ceramic, alumina, and yttrium alloy. The heat resistant coating 64 enhances the heat resistant strength of the wall surface whose strength is weaker than that of other portions due to the large number of holes 53.

  The curved surface portion 58 has a large radius of curvature and is approximately 10 mm. Due to the large radius of curvature, the stress concentration at the corner is small. The bottom portion 54 faces the wall 51 substantially in parallel. The bottom portion 54 and the flat plate portion 56 form an obtuse angle of about 100 degrees. Therefore, the stress concentration at the corner is even smaller.

  The housing 52 is formed by press working. The bottom portion 54 has a shape in which a central region far from the curved surface portion 58 is slightly recessed with respect to a region near the curved surface portion 58. This concave shape is a shape normally found at the bottom of a workpiece formed by pressing.

  Inside the wall 51, a cooling groove 26 is provided in the axial direction of the combustor body 2. The cooling groove 26 is provided so as to be displaced from the hole 53, and does not communicate with the hole 53. An end (not shown) of the cooling groove 26 is connected to an inlet through which cooling air or steam is introduced.

  When the turbine is operated, such an acoustic liner 50 operates as follows.

  Cooling air or steam flows through the cooling groove 68. Thereby, the wall 51 is cooled effectively.

  The combustion gas vibrates in the hole 53. The vibration is attenuated by the friction between the combustion gas and the wall surface of the hole 53. That is, when the housing 52 is compared with a spring, the hole 53 functions as a damper that converts vibration of the spring into heat and attenuates it. As a result, combustion vibration of the combustor is suppressed.

  Purge air flows from the purge hole 60 into the housing 52. The purge air that has flowed in increases the pressure inside the housing 52, and the combustion gas is prevented from flowing into the housing 52 from the hole 53. Cooling air further flows into the housing 52 from the cooling holes 62. The cooling air cools the wall 51. Therefore, by providing the hole 53, the wall surface whose strength is weaker than other regions is effectively cooled. Since the cooling hole 62 is provided in the flat plate portion 56 and is closer to the wall 51 than the purge hole 60, the cooling air flowing from the cooling hole 62 effectively cools the wall 51.

  Such an acoustic liner 50 effectively suppresses acoustic vibration having a frequency higher than that of the acoustic damper 10. By using both the acoustic liner 50 and the acoustic damper 10, the combustion vibration of the combustor is effectively suppressed at a wide range of frequencies.

  Referring to FIG. 7, the sound absorbing performance can be secured in a wide frequency range by having both the acoustic damper and the acoustic liner.

FIG. 1 is a view showing a combustor to which an acoustic damper is attached. FIG. 2 is a view of the acoustic damper as viewed from a direction perpendicular to the bypass elbow. FIG. 3 is a diagram illustrating a state in which a part of the acoustic damper is disassembled. FIG. 4 is a diagram illustrating an internal configuration of the acoustic damper. FIG. 5 is a diagram illustrating the configuration of the curve of the pipe line of the acoustic damper. FIG. 6 is a diagram illustrating the principle of a resonance tube including a plurality of resistors. FIG. 7 is a diagram illustrating the sound absorption characteristics of the acoustic damper and the acoustic liner. FIG. 8 is a diagram illustrating an internal configuration of a resonance box of the acoustic damper. FIG. 9 shows the configuration of the acoustic liner.

Explanation of symbols

2 ... Combustor body 4 ... Car compartment 5 ... Car compartment wall 6 ... Bypass elbow 7 ... Bypass 8 ... Bypass valve 9 ... Resonance box 10 ... Acoustic damper 11 ... Cassette 13 ... Holder 21 ... Gas inlet 22 ... First layer 24 ... Second layer 25 ... transfer layer 28 ... gas inlet 30 ... partition 31 ... corner 32 ... fender 33 ... pipe end 34 ... purge hole 35 ... taper part 36 ... oil drain hole 37 ... porous metal 38 ... porous metal 39 ... pipe 41 ... borescope hole 42 ... corner 43 ... guide 50 ... acoustic liner 51 ... wall 52 ... housing 53 ... hole 54 ... bottom 56 ... flat plate 57 ... side 58 ... curved surface 60 ... purge hole 62 ... Cooling hole 64 ... heat resistant coating 68 ... cooling groove

Claims (21)

A member for forming a duct having an opening therein;
A sound damper comprising: a resistor that provides resistance to the fluid flowing through the pipe. A member that forms an internal pipe having an opening and at least one refracting portion whose direction changes at an angle of 90 degrees or more;
A sound damper comprising: a resistor that provides resistance to the fluid flowing through the pipe. The acoustic damper according to claim 1 or 2,
The shape of the duct is a spiral acoustic damper. In the acoustic damper according to any one of claims 1 to 3,
The acoustic damper is attached to a combustor of a gas turbine,
The said pipe line has a hole which connects the inside of the said pipe line, and the inside of the compartment which stores the said combustor. In the acoustic damper according to any one of claims 1 to 4,
The cross section of the pipe is a square or a circle. In the acoustic damper according to any one of claims 1 to 5,
An acoustic damper, further comprising: a guide provided at a corner where the direction of the pipe line changes discontinuously and reducing a change in the width of the pipe at the corner. The acoustic damper according to any one of claims 1 to 6,
The said pipe line has a taper part with a large cross-sectional area of the said pipe line, so that it is near the said opening. Acoustic damper. The acoustic damper according to any one of claims 1 to 7,
The resistor includes a first resistor and a second resistor disposed apart from each other. The acoustic damper according to any one of claims 1 to 8,
The resistor is an acoustic damper including a porous metal. The acoustic damper according to claim 9, wherein
The porous metal is an alloy containing nickel and chromium and has a porosity of 90% or more. The acoustic damper according to any one of claims 1 to 8,
The resistor includes an acoustic damper including a metal net. The acoustic damper according to claim 9 or 10,
The porous metal is an acoustic damper fixed by brazing. The acoustic damper according to any one of claims 1 to 12,
And a cassette for holding the resistor.
The member and the cassette are detachable. The acoustic damper according to any one of claims 1 to 13,
The acoustic damper is attached to a bypass pipe attached to a combustion cylinder of a combustor,
The acoustic damper is configured such that the inside of the bypass pipe and the pipe line communicate with each other through the opening. The acoustic damper according to claim 14, wherein
An acoustic damper attached to a bypass pipe coupled in a slidable structure with respect to the combustion cylinder. The acoustic damper according to any one of claims 1 to 15,
Combustion vibration of the combustor to which the acoustic damper is attached is large in the frequency range indicated by f1 to f2,
The length of the pipe line is expressed by the following equation, where T is the temperature of the casing housing the combustor, and α is a constant between 0.7 and 1.2

The acoustic damper indicated by A combustor for a gas turbine comprising the acoustic damper according to any one of claims 1 to 16. The combustor for a gas turbine according to claim 17,
And a combustion cylinder housing which is provided in a predetermined first range of the combustion cylinder and forms a resonance space with the combustion cylinder.
The inside of the combustion cylinder and the resonance space communicate with each other through a plurality of combustion cylinder through holes,
The combustor for a gas turbine, wherein the combustion cylinder housing has a length equal to or greater than a diameter of the combustion cylinder in a circumferential direction of the combustion cylinder. The acoustic damper according to any one of claims 1 to 13,
The acoustic damper is attached to a combustion cylinder of a gas turbine combustor,
A combustion damper formed in the combustion cylinder and the pipe line communicate with each other through the opening. A combustor for a gas turbine comprising the acoustic damper according to claim 19.   A gas turbine comprising the combustor for a gas turbine according to any one of claims 17, 18, and 20.

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