JP2009144975A - Acoustic damper structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acoustic damper structure reducing oscillation intensity. <P>SOLUTION: This acoustic damper structure for attenuating oscillation of a frequency domain of several ten to several hundred order, of combustion oscillation generated when combusting fuel in a combustor, has an acoustic tube 21 and a damper main body 30 separately, the acoustic tube 21 is received inside of the damper main body 30, and at least a part of the acoustic tube 21 is supported by the damper main body 30 through a supporting structure 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an acoustic damper used for reducing combustion vibration of a gas turbine combustor.

Conventionally, a combustion damper of a gas turbine is provided with an acoustic damper that can reduce combustion vibration and that advantageously increases the vibration strength of the combustor body. This acoustic damper attenuates vibrations in a low frequency band (a frequency range on the order of several tens to several hundreds of Hz) among combustion vibrations generated when fuel is burned in a combustor. Resonance tube ”) and the damper body are integrated.
As the above-described acoustic damper and the gas turbine including the acoustic damper, for example, those disclosed in Patent Literature 1 and Patent Literature 2 are known.
Note that combustion vibrations in a high frequency band (frequency range on the order of several KHz) are dealt with by a device (generally called “acoustic liner”) attached to the outer periphery of the combustor body.
JP 2006-266671 A JP 2006-22966 A

  By the way, the above-mentioned acoustic damper is a kind of resonance box, and a large pressure fluctuation is generated inside the acoustic damper, causing vibrations. Further, compressed air flowing into the gas turbine casing on the outer wall surface of the acoustic damper. The fluid force is acting to vibrate. For this reason, there is a possibility that the acoustic damper may be damaged by vibration caused by vibration from inside and outside during operation. In addition, as an excitation force which vibrates an acoustic damper, the pressure fluctuation inside a damper will become a big thing.

In the conventional acoustic damper described in the above-mentioned patent document, the resonance tube is configured integrally with the acoustic damper main body. Accordingly, the situation in which the fluid pressure in the passenger compartment and the pressure fluctuation in the resonance tube are simultaneously affected is severe in terms of vibration strength.
In addition, the conventional acoustic damper has many restrictions because the damper shape is formed by an acoustic tube having a constant diameter, and the damper shape is limited. Furthermore, since the conventional acoustic damper is assembled in a very narrow space, the shape is limited. For this reason, it becomes an angular shape in which local stress is likely to occur, and from this point, the vibration strength becomes severe.

Against this background, there is a need for an acoustic damper structure that can alleviate the problem of vibration intensity in severe conditions for an acoustic damper that simultaneously receives fluid pressure in the passenger compartment and pressure fluctuation in the resonance tube.
The present invention has been made in view of the above circumstances, and an object thereof is to provide an acoustic damper structure that can reduce vibration intensity.

The present invention employs the following means in order to solve the above problems.
The acoustic damper structure according to the present invention is an acoustic damper structure for attenuating vibrations in a frequency range on the order of several tens to several hundreds Hz among combustion vibrations generated when fuel is burned in a combustor. And the damper body are separated, the acoustic tube is housed in the damper body, and at least one portion of the acoustic tube is supported by the damper body via a support structure It is.

  According to the acoustic damper structure of the present invention described above, the acoustic tube and the damper main body are separated from each other, and the acoustic tube is housed inside the damper main body, and at least one portion of the acoustic tube is attached to the damper main body via the support structure. Since it is supported, the damper main body receives the fluid force in the passenger compartment, and the acoustic tube only needs to receive pressure fluctuations generated therein, so that the force can be distributed. In addition, since the acoustic tube and the damper body are separate, the damper body is less susceptible to excitation of pressure fluctuations generated in the acoustic tube, and at least one supporting structure is provided to easily construct the structure from the acoustic tuning frequency. The frequency can be detuned.

  In the above invention, the acoustic tube is preferably divided into a plurality of sections with the same sectional area of the acoustic tube, whereby the diameter of the acoustic tube can be reduced and bending can be easily performed.

  In the above invention, it is preferable to give a mass to the acoustic tube, and thereby, a width that can be changed with respect to the structural frequency of the acoustic tube can be widened.

  In the above invention, it is preferable to provide a connecting portion in the middle of the acoustic tube, so that even if excited by a pressure fluctuation inside the acoustic tube, attenuation can be imparted by a displacement difference of the piping in the connecting portion. it can.

  In the above invention, it is preferable to divide the acoustic tube into a plurality of parts, and to connect the different acoustic tubes via a connecting portion, whereby the piping route and the structural frequency of the divided acoustic tube are different, so that the displacement difference Is likely to occur. Therefore, even if excited by pressure fluctuations inside the acoustic tube, attenuation can be imparted due to the displacement difference of the piping at the connecting portion.

  In the above invention, it is preferable to interpose a leaf spring between the acoustic tube and the damper main body, so that attenuation can be imparted by a displacement difference between the damper main body and the leaf spring.

  A gas turbine according to the present invention is characterized in that a combustor includes the acoustic damper according to any one of claims 1 to 6.

  According to the gas turbine of the present invention described above, since the combustor includes the acoustic damper according to any one of claims 1 to 6, the damper main body receives the fluid force in the passenger compartment and the acoustic tube is generated inside. The force can be dispersed by receiving only the pressure fluctuation. In addition, since the acoustic tube and the damper main body are separate, the damper main body is less susceptible to excitation of pressure fluctuations generated in the acoustic tube, and at least one support structure is provided to easily construct the structure from the acoustic tuning frequency. The frequency can be detuned. Therefore, the gas turbine is provided with an acoustic damper that is easy to tune and has high reliability such as strength.

According to the present invention, in a conventional acoustic damper, an acoustic damper structure with high reliability and durability is achieved by relieving the problem of vibration strength in a severe situation by simultaneously receiving the fluid pressure in the passenger compartment and the pressure fluctuation in the resonance tube. It becomes possible to provide.
In addition, it is possible to improve the reliability and durability of the gas turbine provided with this acoustic damper structure.

Hereinafter, an embodiment of an acoustic damper structure according to the present invention will be described with reference to the drawings.
<First Embodiment>
A first embodiment of an acoustic damper structure according to the present invention will be described with reference to FIGS. 1 to 3.
1 is a cross-sectional view showing an acoustic damper structure according to the present invention, FIG. 2 is a cross-sectional view of a gas turbine equipped with the acoustic damper structure according to the present invention, and FIG. 3 is an enlarged view of a combustor portion of the gas turbine shown in FIG. FIG.

  As shown in FIG. 2, the gas turbine 1 is provided with an air intake port 2, a compressor 3, a combustor 10, and a turbine 4 from the upstream side to the downstream side of the air flow. Then, the air taken in from the air intake 2 is compressed by the compressor 3 and is sent to the combustor 10 as high-temperature and high-pressure compressed air. In the combustor 10, a gas fuel such as natural gas or a liquid fuel such as light oil or light heavy oil is supplied to the compressed air and burned to generate high-temperature and high-pressure combustion gas. The high-temperature and high-pressure combustion gas is injected into the turbine 4 after passing through a tail cylinder 14 described later.

As shown in FIG. 3, the combustor 10 has a combustor body 13 housed and installed in a vehicle compartment 12 formed inside a housing 11. On the downstream side of the combustor body 13, a tail cylinder 14 that communicates with a combustion chamber (not shown) of the combustor body 13 is provided. The tail cylinder 14 is a cylindrical member that connects the combustion chamber and the turbine 4, and the cross-sectional area is narrowed toward the downstream side closer to the turbine 4.
The combustor main body 13 has a substantially cylindrical shape, and a pilot nozzle and a plurality of (for example, eight) main nozzles are installed inside the cylinder. The pilot nozzle is disposed at the axial center position of the combustor body 13, and the main nozzle is disposed at an equal pitch so as to surround the periphery of the pilot nozzle.

The above-described tail cylinder 14 is provided with an acoustic damper 20 and an acoustic liner 50 for attenuating combustion vibrations as a damping device for combustion vibrations.
One acoustic liner 50 is an attenuation device that attenuates combustion vibrations in a high frequency band (a frequency band on the order of several KHz), and is wrapped around the tail cylinder 14 close to the combustor body 13. For example, the acoustic liner 50 includes a perforated plate in which a plurality of sound absorbing holes are formed and formed in a cylindrical shape, and a housing formed around the perforated plate.

The acoustic damper 20 shown in FIG. 1 attenuates vibrations in a low frequency region on the order of several tens to several hundreds Hz among combustion vibrations generated when fuel is burned in the combustor 10. The acoustic damper 20 has an acoustic damper structure in which the acoustic tube 21 and the damper main body 30 are configured separately.
The acoustic tube 21 is housed and installed in a damper main body 30 to be described later. In the illustrated acoustic tube 21, a gas inlet portion 22, a tapered portion 23, and an acoustic tube main body 24 communicate with each other and are integrally connected.

The gas inlet portion 22 has the largest flow path cross-sectional area in the acoustic tube 21.
The tapered portion 23 is a portion that connects between the gas inlet portion 22 and the acoustic tube main body 24. Accordingly, the taper portion 23 has an internal channel cross-sectional area from the gas inlet portion 22 having the largest channel cross-sectional area to the acoustic pipe portion 24 having the smallest channel cross-sectional area, that is, from the gas inlet portion 22 toward the downstream side. Is the part that is gradually squeezed.

The acoustic tube main body 24 is configured by bending a commercially available piping member or the like, for example. In the illustrated configuration example, the gas inlet portion 22 is substantially at the center position of the acoustic tube 21, and the acoustic tube main body 24 connected to the gas inlet portion 22 via the tapered portion 23 has a substantially rectangular spiral shape toward the outer peripheral side. It is bent to become.
The damper main body 30 having a separate structure that houses the acoustic tube main body 24 described above is a box-shaped constituent member that forms the internal space 31. The illustrated damper main body 30 has a substantially rectangular parallelepiped shape. The internal space 31 of the damper main body 30 does not need to have a completely sealed airtight structure.

Further, the acoustic tube main body 24 of the acoustic tube 21 described above is supported by the damper main body 30 via the support structure 40 in a state in which the acoustic tube main body 24 is housed inside the damper main body 30. In the illustrated configuration example, the acoustic tube main body 21 of the acoustic tube 21 is supported by the support structure 40 in the vicinity of the end opposite to the connection portion of the gas inlet portion 22.
In the support structure 40, for example, as shown in FIG. 1B, a support 41 supported by the damper main body 30 holds the acoustic tube main body 24 via a sleeve. Note that the support structure 40 of the acoustic tube main body 24 is not limited to the structure using the support 41 and the sleeve 42 described above. For example, the acoustic tube main body 24 may be partially configured such as a structure using U bolts and nuts. Any structure that can be held is acceptable.

According to the acoustic damper structure configured as described above, the damper main body 30 receives the fluid force acting in the passenger compartment 12 of the combustor 10, and the acoustic pipe 21 installed in the damper main body 30 is disposed inside the acoustic pipe. It is only necessary to receive the pressure fluctuation that occurs. For this reason, in the acoustic damper 20, it becomes possible to disperse | distribute a force to the fluid force and the fluctuation | variation of an internal pressure.
In addition, since the acoustic tube 21 and the damper main body 30 are separate bodies, that is, an internal space 31 exists between the acoustic tube 21 and the damper main body 30, the damper main body 30 is generated in the acoustic tube 21. Therefore, it becomes difficult to receive the excitation of the pressure fluctuation that becomes a relatively large force. Thereby, since the acoustic damper 20 is assembled in the narrow portion in the passenger compartment 12, the conventional problem that the local stress is likely to be generated due to the restriction of the shape is alleviated by adopting the separate structure.

Furthermore, since the acoustic tube 21 described above is supported at least at one place by the support structure 40, the structural frequency can be easily detuned from the acoustic tuning frequency. This is because the use of the above-described separate structure increases the degree of freedom in the position and number of the support structure 40, so that it is easy to detune the structural frequency of the acoustic tube 21 from the acoustic tuning frequency. .
Therefore, the above-described acoustic damper 20 is subjected to the fluid pressure in the passenger compartment 12 and the pressure fluctuation in the acoustic tube (resonance tube) 21 at the same time. High acoustic damper structure.
Moreover, the gas turbine 1 provided with such an acoustic damper 20 eliminates the problem of combustion vibration in the combustor 10 and becomes a product with high reliability and durability.

<Second Embodiment>
Next, a second embodiment of the acoustic damper structure according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
In the acoustic damper 20A shown in FIG. 4, the downstream side of the gas inlet 22 is divided into two. More specifically, the acoustic damper 20A has a common gas inlet portion 22, and the downstream side is divided into two tapered portions 23A and 23B and acoustic tube bodies 24A and 24B. In this case, the acoustic tube main bodies 24A and 24B divided into two on the downstream side of the gas inlet portion 22 are divided into two so that the total area becomes equal.

Further, the vicinity of the outlet side end portions of the acoustic tube main bodies 24A and 24B are supported by the support structures 40A and 40B, respectively. That is, the illustrated acoustic pipe damper 20A is divided into two so as to be symmetrical.
If the acoustic damper 20A having such a configuration is employed, a pipe member having a small diameter can be used for the acoustic tubes 21A and 21B, so that bending can be easily performed. Accordingly, the acoustic damper 20A is provided which can alleviate the problem of vibration intensity in severe conditions by simultaneously receiving the fluid pressure in the passenger compartment 12 and the pressure fluctuations in the acoustic tubes 21A and 21B, and can reduce the manufacturing cost. can do.
In the above-described embodiment, the configuration example in which the downstream side of the gas inlet portion 22 is divided into two parts is shown. However, the present invention is not limited to this. For example, a structure divided into a plurality of parts such as three or four parts is possible. is there.

<Third Embodiment>
Next, a third embodiment of the acoustic damper structure according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
In the acoustic damper 20 </ b> B shown in FIG. 5, a mass 25 is given to the acoustic tube main body 24 of the acoustic tube 21. That is, by attaching the mass 25 having an appropriate weight to an appropriate position of the acoustic tube main body 24, the structural frequency of the acoustic tube 21 can be increased.

  By the way, in the above-described embodiment, one mass 25 is provided and two support structures 40 are provided. However, the structural frequency of the acoustic tube 21 can be adjusted by appropriately adjusting the number and position thereof. Since the range to change spreads, it becomes easy to detune from the acoustic tuning frequency including higher order. That is, it is possible to provide an acoustic damper 20B that can be tuned over a wide range with respect to combustion vibration.

<Fourth Embodiment>
Next, a fourth embodiment of the acoustic damper structure according to the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
In the acoustic damper 20 </ b> C shown in FIG. 6, a connecting portion 45 is provided in the middle of the acoustic tube 21. The connecting portion 45 connects adjacent portions of the spiral acoustic tube main body 24. For example, as shown in FIG. 7, a sleeve 46 is attached to the acoustic tube main body 24 and connected by a band 47.

  With such a configuration, even when the acoustic tube 21 is excited by pressure fluctuations generated inside, the acoustic tube 21 is attenuated by a displacement difference of the piping in the connecting portion 45, that is, the connected acoustic tube main body 24 is displaced differently. Can be granted. Therefore, the vibration of the acoustic tube 21 can be reduced.

<Fifth Embodiment>
Next, a fifth embodiment of the acoustic damper structure according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
In the acoustic damper 20 </ b> D shown in FIG. 8, the acoustic pipe is divided into a plurality of parts and different acoustic pipes are coupled via a connecting portion 45. In the illustrated example, the two acoustic tubes 21A ′ and 21B ′ are divided, and two different acoustic tubes 21A ′ and 21B ′ are connected to each other via a connecting portion 45. In this embodiment, the two acoustic tubes 21A ′ and 21B ′ have different shapes, but may have the same shape.

  With such a configuration, the two divided acoustic tubes 21A ′ and 21B ′ have different piping routes and structural frequencies, and therefore, a difference in displacement is likely to occur. Accordingly, even if excited by pressure fluctuations generated in the acoustic tubes 21A 'and 21B', attenuation can be imparted by the displacement difference of the piping in the connecting portion 45, so that the vibrations of the acoustic tubes 21A 'and 21B' are reduced. Can be reduced.

<Sixth Embodiment>
Finally, a sixth embodiment of the acoustic damper structure according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
In the acoustic damper 20 </ b> E shown in FIG. 9, a leaf spring 35 is interposed between the acoustic tube 21 and the damper main body 30. The leaf spring 35 in this case is bent, for example, in a wave shape, and is installed so that the peak of the waveform is in contact with the outer wall surface of the acoustic tube 21 and the inner wall surface of the damper main body 30.

  With such a configuration, the acoustic tube 21 can be attenuated by a displacement difference generated between the damper main body 30 and the leaf spring 35. Therefore, the vibration of the acoustic tube 21 can be reduced. The outer surface of the acoustic tube 21 with which the leaf spring 35 contacts and the inner surface of the damper main body 30 are preferably subjected to wear-resistant coating or the like as necessary to improve durability.

As described above, the gas turbine 1 of the present invention includes the acoustic dampers 20 and 20A to 20E of the respective embodiments described above in the combustor 10, so that the damper main body 30 receives the fluid force in the vehicle compartment 12, The force can be dispersed by receiving only the pressure fluctuation generated inside the acoustic tube 21. Moreover, since the acoustic tube 21 and the damper main body 30 are separate bodies, the damper main body 30 is less susceptible to excitation of pressure fluctuations generated in the acoustic tube 21, and can be easily provided by providing at least one support structure 40. The structural frequency can be detuned from the acoustic tuning frequency. Therefore, tuning with respect to combustion vibration becomes easy, and the gas turbine 1 including the acoustic dampers 20 and 20A to 20E having high reliability such as strength can be provided.
Note that the present invention is not limited to the above-described embodiment, and can be modified by appropriately combining the implementation liquids as necessary. For example, the leaf spring 35 shown in FIG. Combination with the fifth embodiment is also possible.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment of the acoustic damper structure concerning this invention, (a) is sectional drawing of an acoustic damper structure, (b) is AA sectional drawing of (a). It is sectional drawing which shows the schematic structural example of the gas turbine provided with the acoustic damper structure of this invention. FIG. 3 is a detailed view of the combustor shown in FIG. 2. It is sectional drawing which shows 2nd Embodiment of the acoustic damper structure which concerns on this invention. It is sectional drawing which shows 3rd Embodiment of the acoustic damper structure which concerns on this invention. It is sectional drawing which shows 4th Embodiment of the acoustic damper structure which concerns on this invention. (A) is BB sectional drawing of FIG. 6, (b) is CC sectional drawing of (a). It is sectional drawing which shows 5th Embodiment of the acoustic damper structure which concerns on this invention. It is sectional drawing which shows 6th Embodiment of the acoustic damper structure which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas turbine 10 Combustor 11 Housing 12 Car compartment 13 Combustor main body 14 Cylinder 20, 20A-20E Acoustic damper 21 Acoustic pipe 22 Gas inlet part 23 Taper part 24 Acoustic pipe main body 25 Mass 30 Damper main body 35 Leaf spring 40 Support structure 45 connection

Claims (7)

An acoustic damper structure that attenuates vibrations in the frequency range of the order of several tens to several hundreds of Hz among combustion vibrations generated when fuel is combusted in a combustor,
The acoustic tube and the damper main body are separated, the acoustic tube is housed in the damper main body, and at least one part of the acoustic tube is supported by the damper main body via a support structure. Sound damper structure to play.   The acoustic damper structure according to claim 1, wherein the acoustic tube is divided into a plurality of sections with the same sectional area of the acoustic tube.   The acoustic damper structure according to claim 1, wherein a mass is imparted to the acoustic tube.   The acoustic damper structure according to claim 1, wherein a connecting portion is provided in the middle of the acoustic tube.   The acoustic damper structure according to claim 2 or 3, wherein the acoustic tube is divided into a plurality of parts, and different acoustic tubes are coupled to each other via a connecting portion.   The acoustic damper structure according to any one of claims 1 to 5, wherein a leaf spring is interposed between the acoustic tube and the damper main body.   A gas turbine, wherein the combustor includes the acoustic damper according to any one of claims 1 to 6.

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