JP5907916B2 - Exhaust system - Google Patents

Description

  The present invention, for example, in a gas turbine that supplies fuel to compressed high-temperature, high-pressure air and burns it, supplies the generated combustion gas to the turbine to obtain rotational power, and discharges the exhaust gas burned in the gas turbine. The present invention relates to an exhaust device for discharging.

  The gas turbine is composed of a compressor, a combustor, and a turbine, and the air taken in from the air intake port is compressed by the compressor to become high-temperature / high-pressure compressed air. The fuel is supplied and burned, and the high-temperature and high-pressure combustion gas drives the turbine, and the generator connected to the turbine is driven. In this case, the turbine is configured by alternately arranging a plurality of stationary blades and moving blades in the vehicle interior, and drives the moving blades with combustion gas to rotate the output shaft to which the generator is connected. ing. The combustion gas that has driven the turbine becomes exhaust gas, passes through the exhaust duct, and is discharged from the chimney to the atmosphere.

  Such an exhaust device that exhausts exhaust gas from a gas turbine includes an exhaust duct and a chimney. This exhaust device may emit sound having a low frequency component of several Hz or less to the outside due to resonance of the sound field inside the gas turbine. For example, low-frequency component sounds often have frequencies below human audible sounds and rarely feel strange noises directly, but they can indirectly cause the window frames of houses around the plant to vibrate. There is.

  As a technique for reducing the sound of such a specific low frequency component, for example, there is one described in the following patent document. In the gas turbine exhaust flue described in Patent Document 1, at least a part of the wall of the gas turbine exhaust flue is formed of an acoustic transmission material that sufficiently transmits low-frequency sound of several tens of Hz or less. The resonance silencer described in Patent Document 2 is provided with an opening in the wall surface of the exhaust duct of the gas turbine, and the branch pipe and the resonance box are attached in communication.

Japanese Patent No. 3310931 Japanese Patent No. 3254168

  Although the conventional technology described above can reduce the sound of low frequency components, it is necessary to enlarge the silencer in order to reduce the resonance vibration of the low frequency sound field below the audible sound, and the manufacturing cost is low. It will increase.

  The present invention solves the above-described problems, and an object of the present invention is to provide an exhaust device that suppresses the sound of low-frequency components and simplifies the structure and reduces the cost.

  The exhaust device of the present invention for achieving the above object includes an exhaust duct for flowing exhaust gas in a horizontal direction, a chimney capable of flowing the exhaust gas flowing in the exhaust duct upward in the vertical direction and releasing it into the atmosphere, A bent connecting portion that connects a downstream end portion of the exhaust duct in the flow direction of the exhaust gas and an upstream end portion of the chimney in the flow direction of the exhaust gas; and an inner surface at least in the bending direction of the bent connection portion. And a plurality of protrusions provided.

  Accordingly, the exhaust gas flows in the exhaust duct in the horizontal direction, moves to the chimney through the bent connection portion, flows upward in the vertical direction, and is discharged to the atmosphere from the opening at the upper end. At this time, the exhaust gas passing through the bent connecting portion collides with a plurality of protrusions provided on the inner surface in the bending direction to form a small vortex, so that the exhaust gas is largely separated from the inner surface of the bent connecting portion. It will be suppressed. Therefore, the generation of a large vortex when the exhaust gas passes through the bent connecting portion is suppressed, and the generation of low frequency component sounds can be suppressed. Further, it is only necessary to provide a plurality of protrusions on the bent connecting portion, and the structure can be simplified and the cost can be reduced.

  In the exhaust device of the present invention, the plurality of protrusions are provided on an inner surface on the outer side in the bending direction of the bent connecting portion.

  Therefore, by providing a plurality of protrusions not only on the inner surface in the bending direction but also on the inner surface on the outer side in the bending direction, the exhaust gas passing through the bending connection portion is changed into the inner surfaces on the inner side and the outer side in the bending direction. By colliding with a plurality of protrusions provided on the surface to form a small vortex, large separation of the exhaust gas from the inner surface of the bent connecting portion is suppressed in most regions, and when the exhaust gas passes through the bent connecting portion. Generation of large vortices can be appropriately suppressed.

  In the exhaust device of the present invention, the plurality of protrusions are provided in the exhaust duct on the upstream side in the flow direction of the exhaust gas from the bent connection portion.

  Therefore, since the exhaust gas collides with a plurality of projections before reaching the bent connecting portion to form a small vortex, the plurality of protruding portions in the bent connecting portion appropriately form a small vortex, and the bent connection Large separation of exhaust gas from the inner surface of the portion can be reliably suppressed.

  In the exhaust apparatus of the present invention, the plurality of protrusions are characterized in that the amount of protrusion decreases toward the downstream side in the exhaust gas flow direction.

  Therefore, since the protrusion amount of the protrusion portion decreases toward the downstream side in the exhaust gas flow direction, the flow resistance of the exhaust gas gradually decreases. Can be secured.

  The exhaust device according to the present invention is characterized in that a sound absorbing device is provided downstream of the plurality of protrusions in the flow direction of the exhaust gas.

  Therefore, when the exhaust gas passes through the bent connecting portion, the generation of the low frequency component sound can be suppressed by the plurality of protrusions, and then when the exhaust gas passes through the sound absorbing device, the sound of the high frequency component sound is suppressed. Occurrence can be suppressed.

  According to the exhaust device of the present invention, the exhaust duct and the chimney are connected by the bent connecting portion, and a plurality of protrusions are provided on the inner surface in the bending direction of the bent connecting portion, so that the generation of low frequency component sounds is suppressed. In addition, the structure can be simplified and the cost can be reduced.

FIG. 1 is a schematic diagram illustrating an exhaust device according to Embodiment 1 of the present invention. 2 is a cross-sectional view taken along the line II-II of FIG. 1 showing a cross section of the exhaust duct. FIG. 3 is a schematic view of a gas turbine having the exhaust device of the first embodiment. FIG. 4 is a perspective view of the exhaust device. FIG. 5 is a graph showing the sound pressure level with respect to frequency. FIG. 6 is a schematic diagram illustrating an exhaust device according to Embodiment 2 of the present invention. 7 is a cross-sectional view taken along the line VII-VII in FIG. 6 showing a cross section of the exhaust duct. FIG. 8 is a schematic diagram illustrating an exhaust device according to Embodiment 3 of the present invention.

  Exemplary embodiments of an exhaust device according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

  1 is a schematic diagram illustrating an exhaust device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1 illustrating a cross section of the exhaust duct, and FIG. 3 includes the exhaust device of the first embodiment. FIG. 4 is a schematic view of a gas turbine, FIG. 4 is a perspective view of an exhaust device, and FIG. 5 is a graph showing a sound pressure level with respect to frequency.

  As shown in FIGS. 3 and 4, the gas turbine according to the first embodiment includes a compressor 11 that compresses air, a combustor 12 that combusts air compressed by the compressor 11, and fuel that is generated by the combustor 12. And a turbine 13 that can be rotated by combustion gas (exhaust gas) generated by combustion of a mixed gas of compressed air, and a generator 14 is connected to a rotating shaft of the compressor 11.

  In the gas turbine, an exhaust duct 15 for guiding exhaust gas discharged from the turbine 13 is connected to the turbine 13, and the exhaust duct 15 is connected to a chimney 17 via a bent connection portion 16. In this case, the exhaust duct 15 and the bent connecting portion 16 have a rectangular cross-sectional shape, and the chimney 17 has a circular cross-sectional shape. Therefore, the exhaust gas flows through the exhaust duct 15 in the horizontal direction, is bent at a right angle through the bent connecting portion 16, is guided to the chimney 17, rises up the chimney 17, and is discharged to the atmosphere from the opening at the upper end. The gas turbine is not directly connected to the chimney 17 from the exhaust duct 15 but is connected to an exhaust heat recovery boiler (HRSG) (not shown), and the chimney 17 is connected to the exhaust duct of the exhaust heat recovery boiler. .

  Pressure pulsation generated in the combustor 12 of the gas turbine or turbulent flow of the exhaust gas is amplified by resonance vibration when passing through the exhaust duct 15, the bent connection portion 16, and the chimney 17, and is allowed from the opening of the chimney 17. Sounds with low frequency components below the listening level may be emitted. For example, the sound of the low frequency component is several tens Hz or less (for example, about 1 Hz to 20 Hz). Since this low frequency component is often a frequency component below the human audible sound, humans rarely feel anomalous noise directly, but indirectly the vibration of the window frame of the house around the plant ( It may be a factor that causes backlash.

  The exhaust device according to the first embodiment includes an exhaust duct 15, a bent connecting portion 16, and a chimney 17, and a plurality of protrusions 21 are provided on the inner surface 16 a at least in the bending direction of the bent connecting portion 16. In the exhaust device of the first embodiment, a plurality of protrusions 22 are provided on at least the downstream end of the exhaust duct 15 in the flow direction of the exhaust gas, that is, the bent connecting portion 16 and the upper inner surface 15a of the connecting portion. . Further, in the exhaust device of the first embodiment, a plurality of protrusions 23 are provided on the inner surface 18 a of the flat surface portion that is continuous with the inner surface 16 a of the bent connecting portion 16 in the vertical portion 18 connected to the bent connecting portion 16.

  Each of the protrusions 21, 22, and 23 has a hemispherical shape, but is not limited to this shape, and may be an elliptical spherical shape, a triangular shape, a conical shape, a truncated cone shape, a rectangular shape, or the like. Moreover, although each protrusion part 21,22,23 is arrange | positioned at zigzag form, it is not limited to this arrangement, You may arrange | position linearly and may arrange | position at random. Further, the number of the protrusions 21, 22, and 23 is not limited to this embodiment.

  Further, in the exhaust device of the first embodiment, the sound absorbing device 24 is provided on the downstream side of the plurality of protrusions 21, 22, 23 in the flow direction of the exhaust gas.

  In the exhaust system according to the first embodiment configured as described above, the exhaust gas discharged from the gas turbine flows in the horizontal direction through the exhaust duct 15 and moves to the chimney 17 through the bent connecting portion 16. It flows upward in the vertical direction and is released to the atmosphere through the opening at the upper end.

  When the exhaust gas flows through the exhaust duct 15 in the horizontal direction, the exhaust gas flowing along the inner surface 15 a collides with the plurality of protrusions 22 to form a large number of small vortices. Further, when the exhaust gas flows while bending along the bent connecting portion 16, the exhaust gas flowing along the inner surfaces 16 a and 18 a collides with the plurality of projecting portions 21 and 23 to form many small vortices. Therefore, when the exhaust gas is bent from the exhaust duct 15 and flows through the bent connecting portion 16, the exhaust gas is not largely separated from the inner inner surfaces 15a, 16a, and 18a in the bending direction, and a large vortex is generated. Is suppressed.

  As a result, the exhaust gas is suppressed from generating low-frequency component sounds at the bent connecting portion 16. Thereafter, the exhaust gas flows from the bent connecting portion 16 through the sound absorbing device 24 to the chimney 17, and the sound absorbing device 24 suppresses the generation of high frequency component sounds. That is, as shown in FIG. 5, the conventional sound pressure level is high in the low-frequency region and the high-frequency region, but the sound pressure level is low in most frequency regions. It has become.

  Further, the exhaust gas collides with the plurality of protrusions 21, 22, and 23 in the exhaust duct 15, the bent connection portion 16, and the vertical portion 18, so that the state is extremely high in the vicinity of the inner surfaces 15 a, 16 a, and 18 a. Become. For this reason, the inner surfaces 15a, 16a, 18a of the exhaust duct 15, the bent connecting portion 16, and the vertical portion 18 act as acoustic resistors, and a sound reduction effect can be expected.

  As described above, in the exhaust device of the first embodiment, the exhaust duct 15 that flows the exhaust gas in the horizontal direction, and the chimney 17 that can flow the exhaust gas flowing in the exhaust duct 15 upward in the vertical direction and release it to the atmosphere. A bent connecting portion 16 connecting the downstream end portion of the exhaust duct 15 in the flow direction of the exhaust gas and the upstream end portion of the chimney 17 in the flow direction of the exhaust gas, and at least the inner side of the bent connecting portion 16 in the bent direction. A plurality of protrusions 21 provided on the inner surface 16a are provided.

  Accordingly, the exhaust gas flows in the horizontal direction through the exhaust duct 15, moves to the chimney 17 through the bent connecting portion 16, flows upward through the chimney 17 in the vertical direction, and is discharged to the atmosphere from the opening at the upper end. At this time, the exhaust gas passing through the bent connecting portion 16 collides with a plurality of protrusions 21 provided on the inner surface 16a on the inner side in the bending direction to form a small vortex, thereby exhausting from the inner surface 16a of the bent connecting portion 16. Large separation of gas will be suppressed. Therefore, the generation of large vortices when the exhaust gas passes through the bent connecting portion 16 is suppressed, and the generation of low frequency component sounds can be suppressed. In addition, it is only necessary to provide the plurality of protrusions 21 on the bending connecting portion 16, and the structure can be simplified and the cost can be reduced.

  In the exhaust device of the first embodiment, a plurality of protrusions 22 are provided in the exhaust duct 15 upstream of the bent connecting portion 16 in the flow direction of the exhaust gas. Accordingly, since the exhaust gas collides with the plurality of protrusions 22 and forms small vortices before reaching the bent connecting portion 16, it is possible to appropriately form small vortices by the plurality of protruding portions 21 in the bent connecting portion 16. Thus, large separation of the exhaust gas from the inner surface 16a of the bent connecting portion 16 can be reliably suppressed.

  In the exhaust duct according to the first embodiment, the sound absorbing device 24 is provided on the downstream side in the flow direction of the exhaust gas from the plurality of protrusions 21 in the bent connection portion 16. Therefore, when the exhaust gas passes through the bent connecting portion 16, it is possible to suppress the generation of low frequency component sound by the plurality of protrusions 21, and then when the exhaust gas passes through the sound absorbing device 24, the high frequency component. Generation of noise can be suppressed.

  6 is a schematic view showing an exhaust device according to Embodiment 2 of the present invention, and FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 6 showing a cross section of the exhaust duct. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

  The exhaust device according to the second embodiment includes the exhaust duct 15, the bent coupling portion 16, and the chimney 17, and a plurality of protrusions 21 are provided on the inner surface 16 a in the bending direction of the bent coupling portion 16. A plurality of protrusions 31 are provided on the inner surface 16b on the outer side in the bending direction. Further, in the exhaust device of the second embodiment, a plurality of protrusions 22 are provided on the downstream end of the exhaust duct 15 in the flow direction of the exhaust gas, that is, the bent connection portion 16 and the upper inner surface 15a of the connection portion. A plurality of protrusions 32 are provided on the inner surface 15b. Further, in the exhaust device of the first embodiment, a plurality of protrusions 23 are provided on the inner surface 18a of the flat portion that is continuous with the inner surface 16a of the bent connecting portion 16 in the vertical portion 18 connected to the bent connecting portion 16, and the bent connecting portion is provided. A plurality of protrusions 33 are provided on the inner surface 18 b of the flat surface portion that is continuous with the inner surface 16 b of the bent connecting portion 16 in the vertical portion 18 connected to 16.

  Further, the exhaust device is provided with a plurality of protrusions 41 on the left and right inner surfaces 16 c of the bent connecting portion 16. A plurality of protrusions may be provided on the downstream end of the exhaust duct 15 in the flow direction of the exhaust gas, that is, the bent connecting portion 16 and the left and right inner surfaces of the connecting portion, and the vertical portion connected to the bent connecting portion 16. A plurality of protrusions may be provided on the left and right inner surfaces of 18.

  In the exhaust system according to the second embodiment configured as described above, the exhaust gas discharged from the gas turbine flows in the horizontal direction through the exhaust duct 15 and moves to the chimney 17 through the bent connecting portion 16. It flows upward in the vertical direction and is released to the atmosphere through the opening at the upper end.

  When the exhaust gas flows through the exhaust duct 15 in the horizontal direction, the exhaust gas flowing along the inner surface 15a and the outer surface 15b collides with the plurality of protrusions 22 and 32, so that many small vortices are formed. Further, when the exhaust gas flows through the bent connecting portion 16, the exhaust gas flowing along the inner surfaces 16 a and 18 a and the inner surfaces 16 b and 18 b collides with the plurality of projecting portions 21, 23, 31 and 33. Many small vortices are formed. For this reason, when the exhaust gas flows from the exhaust duct 15 by bending the bent connecting portion 16, the exhaust gas flows against the inner surfaces 15a, 16a, 18a on the inner side in the bending direction and the inner surfaces 15b, 16b, 18b on the outer side in the bending direction. And large vortex generation is suppressed.

  As a result, the exhaust gas is suppressed from generating low-frequency component sounds at the bent connecting portion 16. Thereafter, the exhaust gas flows from the bent connecting portion 16 through the sound absorbing device 24 to the chimney 17, and the sound absorbing device 24 suppresses the generation of high frequency component sounds.

  As described above, in the exhaust apparatus according to the second embodiment, the bent connection portion 16 that connects the downstream end portion in the exhaust gas flow direction in the exhaust duct 15 and the upstream end portion in the exhaust gas flow direction in the chimney 17. A plurality of protrusions 21 and 31 are provided on the inner surface 16a on the inner side in the bending direction and on the inner surface 16b on the outer side in the bending direction.

  Therefore, the exhaust gas passing through the bent connecting portion 16 collides with the plurality of protrusions 21 and 31 provided on the inner inner surface 16a and the outer inner surface 16b in the bending direction to form a small vortex, thereby forming the bent connecting portion 16. The large separation of the exhaust gas from the inner surfaces 16a and 16b is suppressed. That is, when the exhaust gas flows through the bent connecting portion 16, it is easily peeled off from the inner surface 16a on the inner side in the bending direction, and is easily peeled off from the inner surface 16b on the outer side in the bending direction. However, since a plurality of protrusions 21 are provided on the inner surface 16a on the inner side in the bending direction and a plurality of protrusions 31 are provided on the inner surface 16b on the outer side in the bending direction, a small vortex is formed here. , Exfoliation of exhaust gas is suppressed. As a result, the generation of large vortices when the exhaust gas passes through the bent connecting portion 16 is suppressed, and the generation of low frequency component sounds can be suppressed.

  FIG. 8 is a schematic diagram illustrating an exhaust device according to Embodiment 3 of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

  The exhaust device according to the third embodiment includes an exhaust duct 15, a bent connecting portion 16, and a chimney 17, and a plurality of protrusions 21 a, 21 b, and 21 c are provided on an inner surface 16 a in the bending direction of the bent connecting portion 16. . And these protrusion part 21a, 21b, 21c has the protrusion amount small toward the downstream of the flow direction of exhaust gas. Further, in the exhaust device of the third embodiment, a plurality of protrusions 22a and 22b are provided on the downstream end of the exhaust duct 15 in the flow direction of the exhaust gas, that is, the bent connecting portion 16 and the upper inner surface 15a of the connecting portion. Yes. And these protrusion part 22a, 22b has the protrusion amount small toward the downstream of the flow direction of exhaust gas. Further, in the exhaust device of the third embodiment, a plurality of protrusions 23 a and 23 b are provided on the inner surface 18 a of the flat surface portion that is continuous with the inner surface 16 a of the bent connecting portion 16 in the vertical portion 18 connected to the bent connecting portion 16. . And these protrusion part 23a, 23b has the protrusion amount small toward the downstream of the flow direction of exhaust gas.

  That is, the protrusions 21a, 21b, 21c, 22a, 22b, 23a, and 23b are sequentially reduced in the protruding amount toward the downstream side in the flow direction of the exhaust gas. The protrusions 21a, 21b, 21c, the protrusions 22a, 22b, and the protrusions 23a, 23b alone may be reduced in the amount of protrusion toward the downstream side in the exhaust gas flow direction.

  In the exhaust system according to the third embodiment configured as described above, the exhaust gas discharged from the gas turbine flows in the horizontal direction through the exhaust duct 15 and moves to the chimney 17 through the bent connecting portion 16. It flows upward in the vertical direction and is released to the atmosphere through the opening at the upper end.

  When the exhaust gas flows through the exhaust duct 15 in the horizontal direction, the exhaust gas flowing along the inner surface 15a collides with the plurality of protrusions 22a and 22b, so that many small vortices are formed. Further, when the exhaust gas flows through the bent connecting portion 16, the exhaust gas flowing along the inner surfaces 16a and 18a collides with the plurality of protrusions 21a, 21b, 21c, 23a, and 23b, thereby generating a small vortex. Many are formed. Therefore, when the exhaust gas is bent from the exhaust duct 15 and flows through the bent connecting portion 16, the exhaust gas is not largely separated from the inner inner surfaces 15a, 16a, and 18a in the bending direction, and a large vortex is generated. Is suppressed.

  As a result, the exhaust gas is suppressed from generating low-frequency component sounds at the bent connecting portion 16. Thereafter, the exhaust gas flows from the bent connecting portion 16 through the sound absorbing device 24 to the chimney 17, and this sound absorbing device suppresses the generation of high frequency component sounds.

  Further, since the protrusions 21a, 21b, 21c, 22a, 22b, 23a, and 23b are set to be small toward the downstream side in the flow direction of the exhaust gas, the flow resistance of the exhaust gas gradually increases. Thus, a good flow is ensured by preventing turbulent exhaust gas flow.

  As described above, in the exhaust device according to the third embodiment, the plurality of protrusions 21a, 21b, 21c, 22a, 22b, 23a, and 23b are set to have a small protrusion amount toward the downstream side in the exhaust gas flow direction. ing. Therefore, the flow resistance of the exhaust gas gradually decreases, so that a turbulent flow of the exhaust gas can be prevented and a good flow can be ensured.

  In the above-described embodiment, the exhaust device of the present invention is described as being applied to an exhaust system of a gas turbine, but it can also be applied to another exhaust system such as a steam turbine.

DESCRIPTION OF SYMBOLS 11 Compressor 12 Combustor 13 Turbine 14 Generator 15 Exhaust duct 15a, 15b Inner surface 16 Bending connection part 16a, 16b Inner surface 17 Chimney 18 Vertical part 18a, 18b Inner surface 21, 21a, 21b, 21c, 22, 22a, 22b, 23 , 23a, 23b, 31, 32, 33, 41 Projection

Claims (5)

An exhaust duct for flowing exhaust gas horizontally;
A chimney capable of flowing the exhaust gas flowing through the exhaust duct upward in the vertical direction and releasing it into the atmosphere;
A bent connecting portion for connecting a downstream end portion of the exhaust duct in the flow direction of the exhaust gas and an upstream end portion of the chimney in the flow direction of the exhaust gas;
A plurality of projecting portions that are provided at predetermined intervals on the inner surface at least in the bending direction of the bent connecting portion and that exhaust gas flowing along the inner surface of the exhaust duct collides with the outer surface ;
An exhaust device comprising:   The exhaust device according to claim 1, wherein the plurality of protrusions are provided on an inner surface on the outer side in the bending direction of the bent connecting portion.   3. The exhaust device according to claim 1, wherein the plurality of protrusions are provided in the exhaust duct upstream of the bent connection portion in the flow direction of the exhaust gas.   The exhaust device according to any one of claims 1 to 3, wherein the plurality of projecting portions have a projecting amount that decreases toward a downstream side in a flow direction of the exhaust gas.   The exhaust device according to any one of claims 1 to 4, wherein a sound absorbing device is provided downstream of the plurality of protrusions in a flow direction of the exhaust gas.

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