JP6104646B2 - Exhaust duct - 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 duct 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. Then, the combustion gas that has driven the turbine is discharged into the atmosphere through the exhaust duct as exhaust gas.

  In the gas turbine described above, the exhaust duct is provided with a heat insulating material on the inner surface side in order to cope with the high temperature of the exhaust gas. That is, in the conventional exhaust duct, a plurality of stud bolts are fixed to the inner surface of a cylindrical duct with a predetermined interval, and a heat insulating material is uniformly attached. It is configured to be fixed by a nut.

  Examples of such conventional exhaust ducts include those described in Patent Documents 1 to 3 below.

Japanese Patent No. 3659819 Japanese Patent Application Laid-Open No. 09-014576 JP-A-11-117768

  Since the above-described conventional exhaust duct has a high temperature exhaust gas flowing therein at a high speed, it always receives an excitation force, and the heat insulation panel, stud bolt, and duct plate are likely to vibrate. This heat insulation panel is composed of a plurality of divided panels, and receives an excitation force from the exhaust gas, and one panel swings in an uneven shape in the thickness direction with one or more nodes as a boundary. In a conventional exhaust duct, the stud bolt has a proximal end fixed to the inner surface of the duct plate by welding and a distal end fixed to a heat retaining panel (divided panel) with a nut. Therefore, the stud bolt may be damaged due to stress acting on the welded portion of the base end portion thereof due to the vibration of the heat insulation panel.

  The present invention solves the above-described problems, and an object of the present invention is to provide an exhaust duct that prevents damage to a connecting member between a duct plate and a heat insulation panel and improves durability.

  The exhaust duct of the present invention for achieving the above object includes a duct plate having a cylindrical shape, a heat insulating panel that is configured by a plurality of divided panels and is arranged at a predetermined interval on the inner surface side of the duct plate, A reinforcing member that is fixed to the outer surface of the divided panel; a heat insulating material that is disposed between the duct plate and the heat insulating panel; and a connecting member that connects the duct plate and the heat insulating panel. It is characterized by.

  Therefore, the divided panel constituting the heat insulation panel receives the excitation force of the flowing exhaust gas and tries to swing in a concavo-convex shape in the thickness direction with the node as a boundary. A reinforcing member is fixed to the outer surface side of the divided panel. Therefore, the divided panel is less likely to vibrate, stress concentration on the connecting member can be suppressed, and damage to the connecting member between the duct plate and the heat insulating panel can be prevented to improve durability. it can.

  In the exhaust duct according to the present invention, the divided panel is a flat panel having a rectangular shape, and the reinforcing member is configured to be disposed inside an outer edge of the divided panel.

  Therefore, the split panel has high bending rigidity on the center side due to the reinforcing member, so that it does not easily swing in an uneven shape toward the plate thickness direction at the node, and suppresses stress concentration on the connecting member. it can.

  In the exhaust duct of the present invention, the reinforcing member has a ring shape.

  Therefore, when the reinforcing member has a ring shape, the reinforcing member is disposed so as to straddle the nodes of the divided panel, and the amplitude of the divided panel can be effectively suppressed.

  In the exhaust duct according to the present invention, the reinforcing member has a plurality of ring shapes.

  Accordingly, by forming the reinforcing member into a plurality of ring shapes, the reinforcing member is disposed so as to straddle the nodes of the divided panel, and the amplitude of the divided panel can be effectively suppressed.

  In the exhaust duct according to the present invention, the reinforcing member includes a first reinforcing portion having a ring shape and a second reinforcing portion disposed inside the first reinforcing portion.

  Therefore, the reinforcing member is constituted by the ring-shaped first reinforcing portion and the second reinforcing portion arranged inside thereof, so that the reinforcing member is arranged so as to straddle the nodes in the plurality of modes in which the divided panel vibrates. As a result, the amplitude of the divided panel can be effectively suppressed.

  In the exhaust duct of the present invention, the second reinforcing portion has a ring shape.

  Therefore, by making the second reinforcing portion into a ring shape, the amplitude of the divided panel in a plurality of vibration modes can be easily suppressed with a simple configuration.

  In the exhaust duct of the present invention, the second reinforcing portion is characterized by having a T shape in plan view.

  Therefore, the amplitude of the division | segmentation panel in a some vibration mode can be easily suppressed by a simple structure by making a 2nd reinforcement part into T shape.

  In the exhaust duct according to the present invention, the plurality of divided panels are configured such that ends overlap each other and are sandwiched by a pair of support plates from both sides in the thickness direction.

  Therefore, since the end portions of the divided panels are sandwiched between the pair of support plates, if the heat retaining panel vibrates due to the flow of exhaust gas, friction occurs due to the relative movement of the divided panels in contact with each other. The stress acting on the connecting member can be suppressed by the damping effect.

  According to the exhaust duct of the present invention, the heat insulating material is disposed between the duct plate and the heat insulating panel composed of a plurality of divided panels, the duct plate and the heat insulating panel are connected by the connecting member, and the outer surface side of the divided panel Since the reinforcing member is fixed to the panel, the divided panel is less likely to vibrate, stress concentration on the connecting member can be suppressed, and damage to the connecting member between the duct plate and the heat insulating panel is prevented to improve durability. be able to.

FIG. 1 is a front view of a split panel constituting a heat insulation panel in an exhaust duct according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the divided panel constituting the heat insulation panel. FIG. 3 is an operation explanatory view of the divided panel constituting the heat retaining panel in the exhaust duct of the first embodiment. FIG. 4 is a schematic view of a gas turbine having an exhaust duct according to the first embodiment. FIG. 5 is a cross-sectional view of the exhaust duct. FIG. 6 is a cross-sectional view illustrating an exhaust duct according to the first embodiment. FIG. 7 is a front view of the divided panel constituting the heat insulation panel in the exhaust duct according to the second embodiment of the present invention. FIG. 8 is a front view of the divided panel constituting the heat insulation panel in the exhaust duct according to the third embodiment of the present invention.

  Exemplary embodiments of an exhaust duct 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.

  FIG. 1 is a front view of a divided panel constituting a heat retaining panel in an exhaust duct according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view of the divided panel constituting the heat retaining panel, and FIG. FIG. 4 is a schematic diagram of a gas turbine having an exhaust duct of the first embodiment, FIG. 5 is a cross-sectional view of the exhaust duct, and FIG. 6 is a sectional view of the first embodiment. It is sectional drawing showing an exhaust duct.

  As shown in FIG. 4, the gas turbine of the first embodiment includes a compressor 11 that compresses air, a combustor 12 that combusts air compressed by the compressor 11, and fuel and compressed air in the combustor 12. And a turbine 13 that can be rotated by combustion gas (exhaust gas) generated by the combustion of the mixed gas, and a generator 14 is connected to the 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 a chimney 16 is connected to the exhaust duct 15. The gas turbine may be configured such that an exhaust heat recovery boiler (HRSG) is connected to the exhaust duct 15 without connecting the chimney 16.

  As shown in FIG. 5, the exhaust duct 15 is configured such that a heat insulating material 22 is disposed over a predetermined thickness inside a duct plate 21 having a rectangular cylindrical shape, and a heat insulating panel 23 is disposed inside thereof. An exhaust gas passage G is formed inside. Although this thermal insulation panel 23 is mentioned later, it is comprised from the some division | segmentation panel. The plurality of connecting members 24 have base ends fixed to the inner surface of the duct plate 21, leading ends penetrating the heat retaining panel 23 (divided panel 31), and nuts 25 as fixing members are screwed together. A plurality of the connecting members 24 are arranged at predetermined intervals in the circumferential direction and axial direction of the exhaust duct 15 (exhaust gas flow direction), and support the heat insulation panel 23 (divided panel 31) at predetermined intervals inside the duct plate 21. Thus, the heat insulating material 22 is held between the duct plate 21 and the heat insulating panel 23.

  The connecting member 24 connects the duct plate 21 and the heat retaining panel 23, one end thereof is in contact with the inner surface of the duct plate 21, and is joined by a welded portion W <b> 1. The connecting member 24 has a threaded portion 24 a at the other end, and is fastened to the heat retaining panel 23 by passing through the heat retaining panel 23 and screwing the nut 25.

  The heat insulation panel 23 includes a plurality of divided panels 31, and end portions 31a of the plurality of divided panels 31 are overlapped and connected in the thickness direction. That is, in the heat retaining panel 23, the end portions 31a of the plurality of divided panels 31 overlap with each other, and the other end portion of the connecting member 24 penetrates in a state where the positions of the through holes 31b are matched. And the edge part 31a of each division | segmentation panel 31 is the state which the support ring (support plate) 32 fixed to the connection member 24 from the heat insulating material 22 side contacted, and the washer (support plate) 33 contacted from the waste gas passage G side. Thus, the nut 25 is screwed into the threaded portion 24a of the connecting member 24 and is supported. In the divided panel 31, the inner diameter of each through hole 31 b is set larger than the outer diameter of the connecting member 24, so that the divided panel 31 can move with respect to the connecting member 24.

  That is, in the plurality of divided panels 31, the overlapping end portions 31a are sandwiched from the thickness direction by the support ring 32 and the washer 33, and in a surface contact state by the screwing of the nut 25 to the screw portion 24a of the connecting member 24. Supported. In this case, the screwing degree (fastening degree) of the nut 25 is set to such a degree that each of the divided panels 31 with the end portions 31a overlapping can slide with a predetermined frictional force.

  As shown in FIGS. 1 and 2, ribs (reinforcing members) 41 are fixed to the divided panel 31 configured as described above. The rib 41 is fixed to the outer surface side of the divided panel 31, that is, the heat insulating material 22 side of the heat insulating panel 23 by the welded portion W <b> 2.

  In this case, the division panel 31 is a flat panel having a rectangular shape (square shape), and is connected so that end portions (outer edge portions) 31a overlap with each other, and is connected to through holes 31b formed at the four corners of the end portion 31a. The member 24 penetrates and is fastened. The rib 41 has a perfect ring shape, and is arranged on the inner side of the end portion (outer edge portion) 31 a of the divided panel 31.

  Therefore, as shown in FIG. 6, when high-temperature exhaust gas flows in the exhaust duct 15 at a high speed, the heat insulation panel 23 vibrates due to the excitation force, and the heat insulation panel 23 moves relative to the duct plate 21. To do. Since the duct plate 21 and the heat retaining panel 23 are connected by the connecting member 24, when the heat insulating panel 23 vibrates with respect to the duct plate 21, stress acts on the connecting member 24. However, in this embodiment, the ribs 41 are fixed to the plurality of divided panels 31 constituting the heat insulation panel 23. Therefore, the heat retaining panel 23 (divided panel 31) is not easily deformed by the rib 41, and the stress acting on the connecting member 24 is reduced.

  That is, as shown in FIG. 1, when the vibration mode having two nodes S1 and S2 that connect the four corners and intersect each other occurs with respect to the divided panel 31 by the excitation force of the exhaust gas, the divided panel 31 For example, when deforming to the near side of the paper surface in the “+” region, it deforms to the far side of the paper surface in the “−” region. Here, since the split-shaped panel 31 is fixed so that the ring-shaped rib 41 intersects the two nodes S1 and S2, the bending rigidity at each of the nodes S1 and S2 increases, and the “+” region is obtained. And the deformation | transformation to a reverse direction is suppressed in the area | region of "-".

  Further, as shown in FIG. 3, two nodes S11 and S12 that are parallel to the end portion 31a and two nodes that are parallel to the end portion 31a and to the divided panel 31 by the excitation force of the exhaust gas. When a vibration mode having two nodes S21 and S22 orthogonal to S11 and S12 is generated, for example, when the split panel 31 is deformed to the near side of the paper surface in the “+” region, in the “−” region. Deforms to the back side of the page. Here, since the split-shaped panel 31 is fixed so that the ring-shaped rib 41 intersects the four nodes S11, S12, S21, and S22, the bending rigidity at each node S11, S12, S21, and S22. And the deformation in the opposite direction is suppressed in the “+” region and the “−” region.

  And the heat insulation panel 23 is clamped by the end portions 31a of the plurality of divided panels 31 in a surface contact state. Therefore, when the heat insulation panel 23 receives the excitation force and vibrates, the end portions 31a of the respective divided panels 31 slide to generate friction, so that the vibration of the heat insulation panel 23 is attenuated here, and the connection member 24 is moved. The acting stress is suppressed.

  As described above, in the exhaust duct according to the first embodiment, the heat insulating panel is configured by the cylindrical duct plate 21 and the plurality of divided panels 31 and arranged at a predetermined interval on the inner surface side of the duct plate 21. 23, a rib 41 fixed to the outer surface side of the divided panel 31, a heat insulating material 22 disposed between the duct plate 21 and the heat insulating panel 23, and a connecting member 24 connecting the duct plate 21 and the heat insulating panel 23. And are provided.

  Accordingly, the divided panel 31 constituting the heat retaining panel 23 receives the excitation force of the flowing exhaust gas and tends to swing in a concavo-convex shape toward the plate thickness direction with the node S as a boundary. Since 41 is fixed, the rigidity of the divided panel 31 is improved and is difficult to be deformed, and the occurrence of vibration can be suppressed and the stress concentration on the connecting member 24 can be suppressed. The durability of the connecting member 24 with the panel 23 can be prevented and the durability can be improved.

  In the exhaust duct of the first embodiment, the divided panel 31 is a rectangular flat panel, and the ribs 41 are arranged on the inner side of the end portion (outer edge portion) 31 a of the divided panel 31. Therefore, the split panel 31 is less likely to oscillate unevenly in the thickness direction with the node S as a boundary because the rib 41 increases the bending rigidity on the center side, and suppresses stress concentration on the connecting member 24. can do.

  In the exhaust duct of the first embodiment, the rib 41 has a ring shape. Therefore, the rib 41 is disposed so as to straddle many nodes S of the divided panel 31, and the amplitude of the divided panel 31 can be effectively suppressed.

  In the exhaust duct of the first embodiment, the heat insulation panel 23 is composed of a plurality of divided panels 31, the end portions 31 a of the plurality of divided panels 31 are overlapped with each other, and are sandwiched by the support ring 32 and the washer 33 from both sides in the thickness direction. In addition, the nut 24 is fastened to and supported by the screw portion 24 a of the connecting member 24. Therefore, since the end portions 31a of the divided panels 31 are sandwiched, if the heat retaining panel 23 vibrates due to the flow of exhaust gas, friction occurs due to the relative movement of the divided panels 31 in contact with each other. The stress acting on the connecting member 24 can be suppressed due to the effect.

  FIG. 7 is a front view of the divided panel constituting the heat insulation panel in the exhaust duct according to the second embodiment of the present invention.

  In Example 2, as shown in FIG. 7, ribs (reinforcing members) 51 are fixed to the divided panel 31. The rib 51 is fixed to the outer surface side of the divided panel 31 by a welded portion.

  In this case, the division panel 31 is a flat panel having a rectangular shape (square shape), and the ribs 51 are disposed on the inner side of the end portion (outer edge portion) 31 a of the division panel 31. The rib 51 includes a plurality of ring-shaped reinforcing portions, and includes a first ring portion (first reinforcing portion) 52 and a second ring portion (second reinforcing portion) 53 disposed on the inside thereof. ing. In this case, the first ring portion 52 is set to have a larger diameter than the second ring portion 53, and the second ring portion 53 is disposed inside the first ring portion 52.

  Therefore, two nodes S11 and S12 that are parallel to the end 31a with respect to the split panel 31 by the excitation force of the exhaust gas, and 2 that are parallel to the end 31a and orthogonal to the two nodes S11 and S12. When the vibration mode having the nodes S21 and S22 of the book occurs, for example, when the split panel 31 is deformed to the front side of the paper in the “+” region, the split panel 31 is deformed to the far side of the paper in the “−” region. . Here, the split panel 31 is fixed so that the rib 51 having two ring-shaped ring portions 52 and 53 intersects the four nodes S11, S12, S21, and S22. , S12, S21, and S22, the bending rigidity is increased, and deformation in the reverse direction is suppressed in the “+” region and the “−” region.

  Further, when a vibration mode having two intersecting nodes S31 and S32 occurs with respect to the central portion of the division panel 31 due to the excitation force of the exhaust gas, the division panel 31 is, for example, in the “+” region on the paper surface. When deformed to the near side, the image is deformed to the back side of the paper surface in the “−” region. Here, since the second ring portion 53 is fixed to the center portion so that the second ring portion 53 intersects the two nodes S31 and S32, the bending rigidity at each of the nodes S31 and S32 is increased. The deformation in the opposite direction is suppressed in the "" region and the "-" region.

  As described above, in the exhaust duct of the second embodiment, the heat insulating panel 23 is configured by the plurality of divided panels 31, the ribs 51 are fixed to the outer surface side of the divided panels 31, and the ribs 51 are formed by a plurality of ring shapes. The first ring portion 52 and the second ring portion 53 disposed inside the first ring portion 52 are configured.

  Accordingly, the divided panel 31 constituting the heat retaining panel 23 receives the excitation force of the flowing exhaust gas and tends to swing in a concavo-convex shape toward the plate thickness direction with the node S as a boundary. Since 51 is fixed, the rigidity of the divided panel 31 is improved and it is difficult to deform, and the occurrence of vibrations can be suppressed and the stress concentration on the connecting member 24 can be suppressed. The durability of the connecting member 24 with the panel 23 can be prevented and the durability can be improved.

  In this case, since the second ring portion 53 is disposed inside the first ring portion 52, the ring portions 52 and 53 are disposed so as to straddle the nodes S in the plurality of modes in which the divided panel 31 vibrates. As a result, the amplitude of the divided panel 31 can be effectively suppressed. Moreover, by making each ring part 52 and 53 into a ring shape, the amplitude of the division | segmentation panel 31 in a some vibration mode can be easily suppressed with a simple structure.

  FIG. 8 is a front view of the divided panel constituting the heat insulation panel in the exhaust duct according to the third embodiment of the present invention.

  In Example 3, as shown in FIG. 8, ribs (reinforcing members) 61 are fixed to the divided panel 31. The rib 61 is fixed to the outer surface side of the divided panel 31 by a welded portion.

  In this case, the division panel 31 is a flat panel having a rectangular shape (square shape), and the ribs 61 are disposed on the inner side of the end portion (outer edge portion) 31 a of the division panel 31. The rib 61 is composed of a plurality of reinforcing portions, and includes a ring portion (first reinforcing portion) 62 having a ring shape and two linear portions (second reinforcing portions) 63 having two linear shapes arranged on the inside thereof. 64. In this case, the two straight portions 63 and 64 have a T shape in plan view and are arranged so as to be connected to the ring portion 62 inside the ring portion 62.

  Therefore, two nodes S11 and S12 that are parallel to the end 31a with respect to the split panel 31 by the excitation force of the exhaust gas, and 2 that are parallel to the end 31a and orthogonal to the two nodes S11 and S12. When the vibration mode having the nodes S21 and S22 of the book occurs, for example, when the split panel 31 is deformed to the front side of the paper in the “+” region, the split panel 31 is deformed to the far side of the paper in the “−” region. . Here, since the split panel 31 is fixed so that the rib 61 having the ring portion 62 and the straight portions 63 and 64 intersects the four nodes S11, S12, S21, and S22, each node S11, S12. , S21 and S22, the bending rigidity is increased, and deformation in the opposite direction is suppressed in the “+” region and the “−” region.

  As described above, in the exhaust duct of the third embodiment, the heat insulating panel 23 includes the plurality of divided panels 31, the rib 61 is fixed to the outer surface side of the divided panel 31, and the rib 61 is connected to the ring portion 62. It is comprised by the linear part 63,64 of the inside.

  Accordingly, the divided panel 31 constituting the heat retaining panel 23 receives the excitation force of the flowing exhaust gas and tends to swing in a concavo-convex shape toward the plate thickness direction with the node S as a boundary. Since 61 is fixed, the rigidity of the divided panel 31 is improved and it is difficult to be deformed, and the occurrence of vibrations can be suppressed and stress concentration on the connecting member 24 can be suppressed. The durability of the connecting member 24 with the panel 23 can be prevented and the durability can be improved.

  In this case, since the straight portions 63 and 64 having a T-shape are arranged inside the ring portion 62, the nodes S in a plurality of modes in which the ring portion 62 and the straight portions 63 and 64 vibrate the divided panel 31 are used. Therefore, the amplitude of the divided panel 31 can be effectively suppressed. Further, by arranging the straight portions 63 and 64 inside the ring portion 62, the amplitude of the divided panel 31 in a plurality of vibration modes can be easily suppressed with a simple configuration.

  In the second embodiment described above, the rib 51 is configured by the two ring portions 52 and 53, but the number of the ring portions may be three or more. Further, the ring portion is not limited to a perfect circle shape, and may be an elliptical shape. Moreover, in Example 3 mentioned above, although the linear parts 63 and 64 were arrange | positioned so that T shape might be made inside the rib 61, a linear part is not restricted to T shape, X shape, Y shape, etc. It is good.

  The reinforcing member of the present invention is not limited to the ring shape, and may be a T shape, an X shape, a Y shape, or the like.

  In the above-described embodiment, the exhaust duct 15 has a rectangular cross-sectional shape, but is not limited to this shape, and may have a circular cross-sectional shape.

  In the above-described embodiment, the exhaust duct according to the present invention is applied to the exhaust system of the gas turbine. However, the exhaust duct can be applied to the exhaust system of the steam turbine. Steam.

DESCRIPTION OF SYMBOLS 11 Compressor 12 Combustor 13 Turbine 14 Generator 15 Exhaust duct 16 Chimney 21 Duct plate 22 Insulating material 23 Insulating panel 24 Connecting member 25 Nut 31 Split panel 32 Support ring (support plate)
33 Washer (support plate)
41, 51, 61 Rib (reinforcing member)
52 1st ring part (1st reinforcement part)
53 Second ring part (second reinforcing part)
62 Ring part (first reinforcing part)
63,64 Straight part (second reinforcing part)

Claims (8)

A duct plate having a cylindrical shape;
A heat insulating panel that is composed of a plurality of divided panels and is arranged at a predetermined interval on the inner surface side of the duct plate;
A reinforcing member fixed to the outer surface side of the divided panel;
A heat insulating material disposed between the duct plate and the heat insulating panel;
A connecting member for connecting the duct plate and the heat insulation panel;
I have a,
The plurality of divided panels are flat panels having a rectangular shape, end portions are overlapped, and the connecting member is fixed to the through holes formed at the four corners of the end portions.
An exhaust duct characterized by that. Before SL reinforcing member, the exhaust duct according to claim 1, characterized in that it is constituted by being disposed inside the outer edge of the dividing panel.   The exhaust duct according to claim 1, wherein the reinforcing member has a ring shape.   The exhaust duct according to claim 3, wherein the reinforcing member has a plurality of ring shapes.   The exhaust duct according to claim 1 or 2, wherein the reinforcing member includes a first reinforcing portion having a ring shape and a second reinforcing portion disposed inside the first reinforcing portion. .   The exhaust duct according to claim 5, wherein the second reinforcing portion has a ring shape.   The exhaust duct according to claim 5, wherein the second reinforcing portion has a T shape in plan view. The exhaust duct according to any one of claims 1 to 7, wherein the plurality of divided panels are configured to be sandwiched by a pair of support plates from both sides in the thickness direction.

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