JP2023128491A - Seal device and rotary machine - Google Patents

Abstract

To provide a seal device and a rotary machine that can improve swirl reduction effect while reducing a leakage flow.SOLUTION: There is provided a cylindrical seal device that is provided between a rotor extending along an axis and rotatable on the axis and a stator arranged on an outer peripheral side of the rotor to section the space of the rotor and stator into a high and a low pressure side, and covers the outer peripheral side of the rotor, and that also has a seal group which has a dumper seal part provided with a plurality of hole parts on its inner peripheral surface, and a labyrinth seal part connecting with an axis-directional low pressure side of the dumper seal part, protruding from the inner peripheral surface to a radially inner side of the axis, and also extending in a circumferential direction of the axis, wherein a plurality of seal groups are provided side by side in the axial direction.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present disclosure relates to sealing devices and rotating machines.

In rotating machines such as turbines, leakage flow generated from the blade tips of turbine blade rows significantly reduces aerodynamic performance, and therefore it is important to reduce leakage flow. Seals are used to reduce leakage flow.
Furthermore, a swirl having a velocity component in the circumferential direction is generated in the seal portion due to the rotation of the rotor. When a displacement occurs in the rotor, a swirl flowing through the seal portion generates an uneven pressure distribution, and a force in a direction perpendicular to the rotor displacement acts on the rotor. Hereinafter, this force will be referred to as "seal excitation force." The seal excitation force may promote whirling of the rotor, reduce the stability of the shaft system, and cause unstable self-excited vibrations. Reducing the seal excitation force is important from the viewpoint of shaft system stability, and there is a need to reduce the swirl that causes the seal excitation force.

For example, Patent Document 1 discloses a seal that achieves both the two effects of reducing leakage flow and reducing swirl. This seal is provided with a damper seal portion having a plurality of holes in the sealing surface and a labyrinth seal portion having an annular parallel groove. The damper seal portion is provided on the high pressure side of the seal, and the labyrinth seal portion is provided on the low pressure side of the seal. Although the labyrinth seal portion tends to increase swirl more easily than the damper seal portion, it is possible to reduce the leakage flow rate. Further, although the damper seal portion tends to have an increased leakage flow rate compared to the labyrinth seal portion, swirl can be reduced.

Japanese Patent Application Publication No. 2010-38114

By the way, the swirl reduction effect of the damper seal portion becomes weaker toward the low pressure side. For this reason, in the seal described in Patent Document 1, a region where swirl can hardly be reduced occurs on the low-pressure side of the damper seal portion. Further, in the labyrinth seal portion, there are many regions where swirl increases due to rotation with the rotor. For this reason, the seal of Patent Document 1 was unable to sufficiently exhibit the swirl reduction effect.

The present disclosure has been made in order to solve the above problems, and an object of the present disclosure is to provide a seal device and a rotating machine that can improve the swirl reduction effect while reducing leakage flow.

In order to solve the above problems, a sealing device according to the present disclosure is provided between a rotor that extends along an axis and is rotatable about the axis, and a stator that is disposed on the outer peripheral side of the rotor, A cylindrical seal device that covers the outer peripheral side of the rotor and divides a space between the rotor and the stator into a high-pressure side and a low-pressure side, the damper seal having a plurality of holes on the inner peripheral surface. a labyrinth seal portion provided with a first fin portion that is continuous with the low pressure side of the damper seal portion in the axial direction, protrudes radially inward from the inner circumferential surface of the axis, and extends in the circumferential direction of the axis; A plurality of the seal groups are provided in line in the axial direction.

A sealing device according to the present disclosure is provided between a rotor that extends along an axis and is rotatable around the axis, and a stator that is disposed on the outer peripheral side of the rotor, and that seals a space between the rotor and the stator. A cylindrical sealing device that covers the outer peripheral side of the rotor and partitions it into a high pressure side and a low pressure side, the first fin protruding from the inner peripheral surface inward in the radial direction of the axis and extending in the circumferential direction of the axis. and a second fin portion that projects inward in the radial direction from the inner circumferential surface and extends in the axial direction.

A rotating machine according to the present disclosure includes a rotor that extends along an axis and is rotatable about the axis, a stator that is disposed on an outer peripheral side of the rotor, and a rotor that is provided between the rotor and the stator, and that is provided between the rotor and the stator. and a cylindrical sealing device that covers the outer peripheral side of the rotor and partitions a space between the rotor and the stator into a high-pressure side and a low-pressure side, and the sealing device has a plurality of holes provided in an inner peripheral surface. a damper seal portion, and a first fin portion that is continuous with the low pressure side of the damper seal portion in the axial direction, projects from an inner circumferential surface inward in the radial direction of the axis, and extends in the circumferential direction of the axis. A seal group having a labyrinth seal portion is provided, and a plurality of the seal groups are provided in line in the axial direction.

According to the seal device and rotating machine of the present disclosure, it is possible to improve the swirl reduction effect while reducing leakage flow.

FIG. 1 is a side view of a gas turbine according to a first embodiment of the present disclosure. 2 is an enlarged view of section II in FIG. 1. FIG. FIG. 2 is a schematic diagram showing the arrangement of a damper seal part and a labyrinth seal part in a seal device according to a first embodiment of the present disclosure. FIG. 2 is a perspective view showing a damper seal portion according to the first embodiment of the present disclosure. FIG. 2 is a schematic diagram showing a cross section of a labyrinth seal portion according to the first embodiment of the present disclosure. FIG. 3 is a diagram showing a change in swirl speed with respect to an axial position of the seal device according to the first embodiment of the present disclosure. It is a perspective view showing the damper seal part concerning the first modification of the first embodiment of this indication. It is a perspective view showing the damper seal part concerning the second modification of the first embodiment of this indication. It is a schematic diagram showing the cross section of the labyrinth seal part concerning the third modification of the first embodiment of this indication. It is a schematic diagram showing the cross section of the labyrinth seal part concerning the fourth modification of the first embodiment of this indication. It is a schematic diagram showing the cross section of the labyrinth seal part concerning the fifth modification of the first embodiment of this indication. FIG. 7 is a schematic diagram showing the arrangement of a damper seal part and a labyrinth seal part in a seal device according to a second embodiment of the present disclosure. FIG. 7 is a schematic diagram showing the arrangement of a damper seal part and a labyrinth seal part in a seal device according to a third embodiment of the present disclosure. FIG. 7 is a schematic diagram showing a cross section of a labyrinth seal portion according to a fourth embodiment of the present disclosure.

<First embodiment>
Hereinafter, a sealing device 50 according to a first embodiment of the present disclosure and a turbine 10 (an example of a rotating machine) including the sealing device 50 will be described with reference to FIGS. 1 to 6. Turbine 10 is part of the configuration of gas turbine 1.

(gas turbine)
A gas turbine 1 according to the present embodiment shown in FIG. 1 is used, for example, in an aircraft propulsion jet engine, a power generation gas turbine, or the like. The gas turbine 1 is driven by a compressor 2 that generates compressed air, a combustor 9 that generates combustion gas G (an example of a fluid) by mixing fuel with the compressed air, and burning the mixture. A turbine 10 is provided.

(compressor)
The compressor 2 includes a compressor rotor 3 that is rotatable around an axis O, and a compressor casing 4 that covers the compressor rotor 3 from the outer peripheral side. The compressor rotor 3 is formed into a columnar shape extending along the axis O. A plurality of compressor rotor blade stages 5 are provided on the outer peripheral surface of the compressor rotor 3 and arranged at intervals in the direction of the axis O. Each compressor rotor blade stage 5 has a plurality of compressor rotor blades arranged on the outer peripheral surface of the compressor rotor 3 at intervals in the circumferential direction of the axis O.

The compressor casing 4 is formed into a cylindrical shape centered on the axis O. A plurality of compressor stator vane stages 7 are provided on the inner circumferential surface of the compressor casing 4 and arranged at intervals in the direction of the axis O. These compressor stationary blade stages 7 are arranged alternately in the direction of the axis O with respect to the compressor rotor blade stages 5 described above. Each compressor stator vane stage 7 has a plurality of compressor stator vanes arranged on the inner peripheral surface of the compressor casing 4 at intervals in the circumferential direction of the axis O.

(combustor)
The combustor 9 is provided between the compressor 2 and the turbine 10 continuing downstream (on the right side in FIG. 1). The compressed air generated by the compressor 2 is mixed with fuel inside the combustor 9 to become a premixed gas. The premixed gas is combusted in the combustor 9 to generate high-temperature, high-pressure combustion gas G, and the combustion gas G is guided into the turbine 10 .

(turbine)
The turbine 10 includes a rotor 11 rotatable around an axis O, a stator 12 surrounding the rotor 11, and a sealing device 50 (see FIG. 2).

(rotor)
The rotor 11 extends in the direction of the axis O and is rotatable around the axis O.
Hereinafter, the axis O of the rotor 11 may be simply referred to as "axis O". Further, the direction of the axis O of the rotor 11 may be simply referred to as the "axis O direction," the radial direction of the axis O may be simply referred to as the "radial direction," and the circumferential direction of the axis O may simply be referred to as the "circumferential direction."

The rotor 11 includes a rotating shaft 11a, a plurality of turbine blade stages 20, and a rotor-side fin portion 51 (see FIG. 5).
The rotating shaft 11a is formed into a columnar shape extending along the axis O. The rotating shaft 11a is integrally connected to the compressor rotor 3 in the direction of the axis O, thereby forming a gas turbine rotor that rotates around the axis O.

The plurality of turbine rotor blade stages 20 are provided on the outer circumferential surface of the rotating shaft 11a, and are arranged at intervals in the axis O direction.
As shown in FIGS. 1 and 2, each turbine rotor blade stage 20 includes a plurality of turbine rotor blades 30 and an annular shroud 42. As shown in FIGS.

The plurality of turbine rotor blades 30 are arranged at intervals in the circumferential direction of the axis O on the outer peripheral surface of the rotating shaft 11a.
The shroud 42 is provided at the blade tips of the plurality of turbine rotor blades 30, and increases the rigidity of the turbine rotor blade stage 20 by being integrated with the turbine rotor blades 30 arranged in the circumferential direction of the axis O.
Hereinafter, the outer circumferential surface of the shroud 42 may be referred to as the outer circumferential surface of the rotor 11.

The rotor-side fin portion 51 shown in FIG. 5 is provided on the outer circumferential surface of the rotor 11 (the outer circumferential surface of the shroud 42). The rotor-side fin portion 51 cooperates with the seal device 50 to prevent the combustion gas G from leaking. Details of the rotor-side fin portion 51 will be described later together with the sealing device 50.

(stator)
As shown in FIGS. 1 and 2, the stator 12 is arranged on the outer peripheral side of the rotor 11. As shown in FIGS. The stator 12 includes a turbine casing 15, a plurality of turbine stator blade stages 13, and an annular retaining ring 40.

The turbine casing 15 has a cylindrical shape centered on the axis O.
The plurality of turbine stationary blade stages 13 are provided on the inner peripheral side of the turbine casing 15 and are arranged at intervals in the axis O direction. These turbine stationary blade stages 13 are arranged alternately in the axis O direction with respect to the turbine rotor blade stages 20 described above.
Each turbine stationary blade stage 13 has a plurality of turbine stationary blades 14 arranged near the inner circumferential surface of the turbine casing 15 at intervals in the circumferential direction of the axis O.

The retaining ring 40 is annularly provided over the inner circumferential surface of the turbine casing 15 . The retaining ring 40 is provided to prevent the high-temperature, high-pressure combustion gas G from coming into direct contact with the turbine casing 15. The same number of retaining rings 40 as the number of turbine rotor blade stages 20 are provided on the inner peripheral surface of the turbine casing 15 so as to correspond to the turbine rotor blade stages 20 .
As shown in FIG. 2, the turbine stationary blades 14 are supported so as to straddle between the retaining rings 40 adjacent to each other in the direction of the axis O.
A sealing device 50 is provided between the turbine rotor blade 30 and the retaining ring 40.

(Seal device)
Seal device 50 is provided between rotor 11 and stator 12. The seal device 50 is a cylindrical member that covers the outer peripheral side of the rotor 11. The space between the rotor 11 and the stator 12 is divided into a high pressure side HP and a low pressure side LP. Thereby, the sealing device 50 prevents the combustion gas G from leaking from between the turbine rotor blade 30 and the retaining ring 40 into the space near the turbine stationary blade 14 located in the subsequent stage.

In this embodiment, with the seal device 50 as a reference, the upstream side where the combustion gas G flows in is the high pressure side HP, and the downstream side where the combustion gas G flows out is the low pressure side LP.
Hereinafter, the high pressure side HP in the direction of the axis O may be simply referred to as the "high pressure side HP", and the low pressure side LP in the direction of the axis O may be simply referred to as the "low pressure side LP".

As shown in FIG. 3, the sealing device 50 includes a seal group 50a having a damper seal portion 60 and a labyrinth seal portion 70 continuous to the low pressure side LP of the damper seal portion 60 in the axis O direction. In one seal group 50a, the damper seal part 60 is arranged on the high pressure side HP, and the labyrinth seal part 70 is arranged on the low pressure side LP. A plurality of seal groups 50a are provided side by side in the axis O direction. Therefore, the damper seal portions 60 and the labyrinth seal portions 70 are arranged alternately in the direction of the axis O.

(damper seal part)
As shown in FIGS. 3 and 4, a plurality of damper seal parts 60 are provided so as to be lined up in the axis O direction with the labyrinth seal part 70 in between.
Note that the dimension of the damper seal portion 60 in the direction of the axis O can be changed as appropriate.
The damper seal portion 60 has a hole structure. A plurality of holes 61 are provided on the inner peripheral surface of the damper seal portion 60.

(hole)
The plurality of holes 61 are provided throughout the inner circumferential surface of the damper seal portion 60 in the axis O direction and in the circumferential direction. The hole 61 opens radially inward. The hole portion 61 is a cylindrical hole extending in the radial direction. That is, the hole 61 is formed in a circular shape when viewed from the opening direction. The plurality of holes 61 are all formed to have the same hole diameter.

The plurality of holes 61 are arranged in a staggered manner when viewed from the inside in the radial direction. Specifically, a structure in which six holes 61 are arranged so as to surround one hole 61 is formed over the entire inner peripheral surface of the damper seal portion 60 . The plurality of holes 61 are arranged at equal intervals in the axis O direction and the circumferential direction. That is, the plurality of holes 61 are arranged in the closest density on the inner peripheral surface of the damper seal part 60.

Further, the plurality of holes 61 arranged in the axis O direction form a hole row extending in the axis O direction. A plurality of hole rows are formed in the damper seal portion 60. The plurality of hole rows are arranged in an annular shape when viewed from the direction of the axis O.
Note that the number of holes 61 can be changed as appropriate.

(Labyrinth seal part)
As shown in FIG. 3, a plurality of labyrinth seal parts 70 are provided so as to be lined up in the axis O direction with the damper seal part 60 interposed therebetween.
Note that the dimensions of the labyrinth seal portion 70 in the axis O direction may be changed as appropriate.
As shown in FIG. 5, a first fin portion 71 is provided on the inner peripheral surface of the labyrinth seal portion 70. As shown in FIG.

(first fin part)
The first fin portion 71 protrudes radially inward from the inner peripheral surface of the labyrinth seal portion 70. Further, the first fin portion 71 extends in the circumferential direction. The circumferential cross section of the first fin portion 71 is formed into a trapezoidal shape that tapers toward the inside in the radial direction. A plurality of first fin portions 71 are provided side by side in the axis O direction.
Note that the number of first fin portions 71 can be changed as appropriate.

(Rotor side fin part)
The rotor 11 is provided with a rotor-side fin portion 51 that is arranged adjacent to the first fin portion 71 in the axis O direction. The rotor-side fin portion 51 protrudes radially outward from the outer peripheral surface of the rotor 11.
Further, the rotor side fin portion 51 extends in the circumferential direction. The circumferential cross section of the rotor-side fin portion 51 is formed into a trapezoidal shape that tapers toward the outside in the radial direction.
Note that the number of rotor-side fin portions 51 can be changed as appropriate.

As shown in FIG. 5, the sealing device 50 and rotor 11 described above are arranged such that the first fin portion 71 and the rotor-side fin portion 51 are alternately intertwined. Such a seal device 50 and rotor 11 are referred to as an interlocking type.

(effect)
Next, the effect of reducing swirl by the sealing device 50 described above will be explained with reference to FIG. 6 and the like. In FIG. 6, a schematic diagram of the sealing device 50 is illustrated on the upper side, and a graph showing changes in swirl speed with respect to the position in the axis O direction is illustrated on the lower side. The horizontal axis of the lower graph indicates the position P in the axis O direction corresponding to the schematic diagram of the sealing device 50 above, and the vertical axis indicates the swirl flow velocity V.
By the way, when the rotor 11 described above rotates, a shearing force is applied from the rotor 11 to the combustion gas G around the rotor 11 in the rotation direction. A swirl having a velocity component in the circumferential direction is generated by the action of this shear force. The combustion gas G containing this swirl tends to flow from the high pressure side HP toward the low pressure side LP due to the pressure difference (static pressure difference) on both sides in the direction of the axis O.

The combustion gas G is first guided to the damper seal portion 60 on the highest pressure side HP. The combustion gas G guided to the damper seal portion 60 flows into each hole portion 61 from the inside in the radial direction. The combustion gas G guided into the hole 61 becomes a spiral vortex along the inner peripheral surface of the hole 61 due to the velocity component in the circumferential direction. As a result, the swirl contained in the combustion gas G collides with the inner circumferential surface of the hole 61 and is reduced. The swirl is gradually reduced toward the low pressure side LP.

When the swirl is hardly reduced, the combustion gas G is guided to the labyrinth seal portion 70. Although the labyrinth seal portion 70 can reduce leakage flow more than the damper seal portion 60, the swirl gradually increases toward the low pressure side LP.

Before the swirl increases to an unacceptable extent, the combustion gas G is guided to the damper seal portion 60 on the one lower pressure side LP. This again reduces swirl. When the swirl is reduced, it is guided again to the damper seal portion 60 of one low pressure side LP.
In this way, the sealing device 50 prevents the swirl from increasing to an unacceptable extent and maintains a low swirl state by allowing the combustion gas G to pass through the damper seal section 60 and the labyrinth seal section 70 alternately. ing.

In the present embodiment, the seal device 50 includes a seal group 50a that includes a damper seal portion 60 and a labyrinth seal portion 70 that is continuous to the low pressure side LP in the axis O direction of the damper seal portion 60. A plurality of seal groups 50a are provided side by side in the axis O direction.

In this embodiment, the damper seal section 60 causes the combustion gas G to flow into the hole section 61 to reduce swirl. In addition, the labyrinth seal section 70 makes the fluid path convoluted by the first fin section 71 to reduce leakage flow of the fluid. That is, in the seal device 50 of this embodiment, the damper seal portion 60 reduces swirl, and the labyrinth seal portion 70 reduces leakage flow. According to this embodiment, within one seal group 50a, the damper seal portion 60 is disposed on the higher pressure side HP than the labyrinth seal portion 70. Therefore, the combustion gas can be introduced to the labyrinth seal section 70 after reducing the swirl at the damper seal section 60. Thereby, even if the swirl increases in the labyrinth seal portion 70, it is possible to suppress the swirl from increasing to an unacceptable level.

Further, the damper seal portions 60 and the labyrinth seal portions 70 are arranged alternately in the axis O direction. Therefore, the length of the damper seal part 60 in the axis O direction is adjusted so that the swirl does not reach a level where the swirl reduction effect of the damper seal part 60 cannot be obtained, and the swirl in the labyrinth seal part 70 does not reach a high level. Thus, the length of the labyrinth seal portion 70 in the direction of the axis O can be adjusted. Thereby, it is possible to improve the swirl reduction effect while reducing leakage flow. That is, the swirl reduction effect of the damper seal portion 60 can be utilized to the fullest.

Further, the sealing device 50 can damp the self-excited vibration of the rotor 11 due to the swirl by reducing the swirl with the damper seal portion 60. Thereby, the shaft system including the rotor 11, the seal device 50, etc. can be stabilized.

In this embodiment, the rotor 11 is provided with a rotor-side fin portion 51 that projects radially outward from the outer peripheral surface and extends in the circumferential direction. The rotor-side fin portion 51 is arranged adjacent to the first fin portion 71 in the axis O direction.

According to this embodiment, the path of the fluid flowing through the labyrinth seal portion 70 can be made more complicated by the first fin portion 71 and the rotor-side fin portion 51. Thereby, the leakage flow reduction effect of the labyrinth seal portion 70 can be increased.

In addition, in the said first embodiment, although the hole part 61 presupposed that it is a cylindrical hole extended in the radial direction, it is not limited to this. The hole 61 may be, for example, a prismatic hole extending in the radial direction.

In the first embodiment, the plurality of holes 61 are arranged in a staggered manner when viewed from the inside in the radial direction, but the invention is not limited to this. The plurality of holes 61 may be arranged in a rectangular grid shape when viewed from the inside in the radial direction.

Next, a first modification of the first embodiment will be described with reference to FIG. 7.
As shown in FIG. 7, the damper seal portion 60 may have a pocket damper structure. In this case, the damper seal portion 60 has a plurality of first pocket fin portions 62 extending in the direction of the axis O and a plurality of second pocket fin portions 63 extending in the circumferential direction on the inner peripheral surface. The first pocket fin portion 62 and the second pocket fin portion 63 are arranged to be orthogonal to each other. The hole portion 61 is defined by a first pocket fin portion 62 and a second pocket fin portion 63. Therefore, the hole 61 becomes a rectangular hole.

Next, a second modification of the first embodiment will be described with reference to FIG. 8.
As shown in FIG. 8, the damper seal portion 60 may have a honeycomb structure. In this case, the hole 61 has a regular hexagonal cross section and penetrates in the radial direction. The damper seal portion 60 is lined with such holes 61 without any gaps.

Next, a third modification of the first embodiment will be described with reference to FIG. 9.
As shown in FIG. 9, the labyrinth seal portion 70 of the seal device 50 and the rotor 11 may be of a so-called straight type in which the rotor 11 is not provided with the rotor-side fin portion 51. A portion of the outer peripheral surface of the rotor 11 that faces the sealing device 50 in the radial direction is formed into a flat surface.

Next, a fourth modification of the first embodiment will be described with reference to FIG. 10.
As shown in FIG. 10, the labyrinth seal portion 70 and rotor 11 of the seal device 50 may be of a so-called stepped type. In this case, the first fin portions 71 are provided such that long and short radial dimensions are alternately arranged in the axis O direction. Further, the rotor-side fin portion 51 is provided so as to face the shorter first fin portion 71 in the radial direction. The circumferential cross section of the rotor-side fin portion 51 is formed in a rectangular shape that is long in the direction of the axis O. The dimension of the rotor-side fin portion 51 in the axis O direction is longer than the dimension of the first fin portion 71 in the axis O direction.

Next, a fifth modification of the first embodiment will be described with reference to FIG. 11.
As shown in FIG. 11, the labyrinth seal portion 70 of the sealing device 50 and the rotor 11 may be of a so-called stepped shape. In this case, the labyrinth seal portion 70 has a radial dimension that becomes shorter from the high pressure side HP toward the low pressure side LP. The plurality of first fin portions 71 arranged in the direction of the axis O are provided so that the radially inner end portions are located radially outward from the high pressure side HP toward the low pressure side LP. Further, the rotor-side fin portion 51 is provided so as to face the first fin portion 71 in the radial direction. The rotor-side fin portion 51 is formed in a step-like manner so that the radial dimension becomes longer from the high-pressure side HP toward the low-pressure side LP.

The damper seal portion 60 and the labyrinth seal portion 70 shown in the first embodiment and each modification can be appropriately selected according to design conditions.

<Second embodiment>
Hereinafter, a sealing device 250 according to a second embodiment of the present disclosure will be described with reference to FIG. 12. In the second embodiment, configurations similar to those in the first embodiment are given the same names and the same reference numerals, and descriptions thereof are omitted as appropriate.

As shown in FIG. 12, the dimension of the damper seal section 260 located on the highest pressure side HP in the axis O direction is larger than the dimensions of the other damper seal sections 260 in the axis O direction. Furthermore, the dimensions of the plurality of damper seal portions 260 in the axis O direction decrease from the high pressure side HP toward the low pressure side LP in the axis O direction.

The dimensions of the plurality of labyrinth seal parts 270 in the axis O direction increase from the high pressure side HP toward the low pressure side LP in the axis O direction.

In this embodiment, the dimension of the damper seal section 260 located on the highest pressure side HP in the axis O direction is larger than the dimensions of the other damper seal sections 260 in the axis O direction.

According to this embodiment, the swirl can be sufficiently reduced by the damper seal section 260 on the highest pressure side HP and then guided to the labyrinth seal section 270 on the low pressure side LP and the other damper seal sections 260. Thereby, the seal excitation force can be further suppressed and the shaft system can be stabilized.

In this embodiment, the dimensions of the plurality of damper seal parts 260 in the axis O direction increase from the high pressure side HP toward the low pressure side LP.

On the low pressure side LP, unstable vibration of the rotor 11 due to swirl is smaller than on the high pressure side HP. Therefore, even if the low-pressure side LP does not reduce swirl as much as the high-pressure side HP, unstable vibration of the rotor 11 due to swirl can be suppressed. According to this embodiment, the damper seal portion 260 on the low pressure side LP, which does not need to reduce the swirl as much as the high pressure side HP, can be made shorter. Therefore, the swirl reduction effect can be further improved.

Further, the length of the labyrinth seal portion 270 can be increased by the length of the damper seal portion 260 on the low pressure side LP. For example, as in the present embodiment, the dimensions of the plurality of labyrinth seal portions 270 in the axis O direction increase from the high pressure side HP toward the low pressure side LP in the axis O direction. Thereby, the effect of reducing the leakage flow rate can be improved.

In the second embodiment, the dimensions of the plurality of damper seal parts 260 in the axis O direction decrease from the high pressure side HP toward the low pressure side LP, but the present invention is not limited to this. Only the damper seal portion 260 on the highest pressure side HP may have a larger dimension in the axis O direction, and the dimensions of the other damper seal portions 260 in the axis O direction may all be equal.

<Third embodiment>
Hereinafter, a sealing device 350 according to a third embodiment of the present disclosure will be described with reference to FIG. 13. In the third embodiment, the same components as those in each of the above embodiments are given the same names and the same reference numerals, and the description thereof will be omitted as appropriate.

As shown in FIG. 13, the dimension in the axis O direction of the labyrinth seal section 370 located on the highest pressure side HP in the axis O direction is larger than the dimensions in the axis O direction of the other labyrinth seal sections 370. Further, the dimensions of the plurality of labyrinth seal portions 370 in the axis O direction decrease from the high pressure side HP toward the low pressure side LP in the axis O direction.

In this embodiment, the dimensions of the plurality of labyrinth seal parts 370 in the axis O direction decrease from the high pressure side HP toward the low pressure side LP in the axis O direction.

The leakage flow on the low pressure side LP is smaller than that on the high pressure side HP. For this reason, it is said that it is not necessary to reduce leakage flow as much on the low pressure side LP as on the high pressure side HP. According to this embodiment, the labyrinth seal portion 370 on the low pressure side LP, which does not need to reduce the leakage flow as much as on the high pressure side HP, can be made shorter. Therefore, the effect of reducing the leakage flow rate can be further improved. Therefore, the swirl reduction effect can be further improved.

<Fourth embodiment>
A sealing device 450 according to a fourth embodiment of the present disclosure will be described below with reference to FIG. 14. In the fourth embodiment, the same components as in each of the above embodiments are given the same names and the same reference numerals, and the description thereof will be omitted as appropriate.

As shown in FIG. 14, the sealing device 450 and the rotor 11 are formed in a stepped shape.
Further, a second fin portion 472 is provided on the inner peripheral surface of all the labyrinth seal portions 470. The second fin portion 472 protrudes radially inward from the inner peripheral surface of the labyrinth seal portion 470. Further, the second fin portion 472 extends in the direction of the axis O. A plurality of second fin portions 472 are provided at intervals in the circumferential direction.

Note that the sealing device 450 may include the damper seal portion 60 and the labyrinth seal portion 470 having the second fin portion 472, or may include only the labyrinth seal portion 470 having the second fin portion 472.

In this embodiment, the labyrinth seal portion 470 is provided with a second fin portion 472 that protrudes radially inward from the inner peripheral surface and extends in the axis O direction.

According to this embodiment, the seal device 450 can reduce swirl by causing the swirl to collide with the second fin portion 472. Thereby, the seal device 450 can reduce swirl even in the labyrinth seal portion 470. Therefore, the seal excitation force can be further reduced and the shaft system can be further stabilized.

Further, when the sealing device 450 is configured only from the labyrinth seal section 470 having the second fin section 472, it is possible to obtain the swirl reduction effect and the leakage flow reduction effect with only one type of structure of the labyrinth seal section 470. can.

In the fourth embodiment, the second fin portions 472 are provided on the inner peripheral surfaces of all the labyrinth seal portions 470, but the present invention is not limited to this. The second fin portion 472 may be provided in at least a portion of the labyrinth seal portion 470.

In the fourth embodiment, a case has been described in which the second fin portion 472 is provided when the sealing device 450 and the rotor 11 are of a stepped type, but the present invention is not limited to this. The second fin portion 472 may be provided when the sealing device 450 and the rotor 11 are of a stepped type or when the sealing device 450 and the rotor 11 are of a straight type.

<Other embodiments>
Although the embodiment of the present disclosure has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes within the scope of the gist of the present disclosure. . Each embodiment and each modification may be combined as appropriate.
In addition, although the said embodiment demonstrated the case where the seal apparatus 50, 250, 350, 450 is used for the gas turbine 1, it is not restricted to this. Seal devices 50, 250, 350, 450 may be used in large rotating machines such as steam turbines and other compressors.

<Additional notes>
The seal devices 50, 250, 350, and 450 described in each embodiment can be understood, for example, as follows.

(1) The seal device 50, 250, 350, 450 according to the first aspect includes a rotor 11 that extends along an axis O and is rotatable about the axis O, and a stator that is disposed on the outer peripheral side of the rotor 11. 12, a cylindrical seal device 50, 250, 350 that covers the outer peripheral side of the rotor 11 and partitions the space between the rotor 11 and the stator 12 into a high pressure side HP and a low pressure side LP, 450, which includes a damper seal part 60, 260 having a plurality of holes 61 on the inner peripheral surface, and a damper seal part 60, 260 that is continuous with the low pressure side LP in the axis O direction of the damper seal part 60, 260, and is connected from the inner peripheral surface. A seal group 50a having a labyrinth seal portion 70, 270, 370, 470 provided with a first fin portion 71 protruding inward in the radial direction of the axis O and extending in the circumferential direction of the axis O; A plurality of groups 50a are provided side by side in the direction of the axis O.
Examples of the fluid include combustion gas G and steam.

In the seal devices 50, 250, 350, 450 of this embodiment, the damper seal portions 60, 260 reduce swirl, and the labyrinth seal portions 70, 270, 370, 470 reduce leakage flow. According to this aspect, the damper seal parts 60, 260 and the labyrinth seal parts 70, 270, 370, 470 are arranged alternately in the direction of the axis O. Therefore, in order to prevent the damper seal parts 60, 260 from reaching a level where the swirl reduction effect cannot be obtained, the lengths of the damper seal parts 60, 260 in the axis O direction are adjusted, and the labyrinth seal parts 70, 270, 370, The length of the labyrinth seal portions 70, 270, 370, 470 in the direction of the axis O can be adjusted so that the swirl does not reach a high level at 470.

(2) The seal device 250 of the second aspect is the seal device 250 of (1), in which the dimension of the damper seal portion 260 located on the highest pressure side HP in the axis O direction is as follows: It may be larger than the dimension of the other damper seal portions 260 in the axis O direction.

According to this aspect, the swirl can be sufficiently reduced by the damper seal section 260 on the highest pressure side HP, and then guided to the labyrinth seal section 270 on the low pressure side LP and the other damper seal sections 260.

(3) The seal device 250 of the third aspect is the seal device 250 of (1) or (2), in which the plurality of damper seal parts 260 are arranged from the high pressure side HP to the low pressure side LP in the direction of the axis O. The dimension in the direction of the axis O may become smaller as the direction increases.

On the low pressure side LP, unstable vibration of the rotor 11 due to swirl is smaller than on the high pressure side HP. Therefore, even if the low-pressure side LP does not reduce swirl as much as the high-pressure side HP, unstable vibration of the rotor 11 due to swirl can be suppressed. According to this aspect, it is possible to shorten the damper seal portion 260 on the low pressure side LP, which does not need to reduce the swirl as much as on the high pressure side HP.

(4) The sealing device 350 of the fourth aspect is the sealing device 350 according to any one of (1) to (3), in which the plurality of labyrinth seal portions 370 are arranged in the direction of the axis O from the high pressure side HP to the low pressure side. The dimension in the direction of the axis O may become smaller toward the side LP.

The leakage flow on the low pressure side LP is smaller than that on the high pressure side HP. For this reason, it is said that it is not necessary to reduce leakage flow as much on the low pressure side LP as on the high pressure side HP. According to this aspect, it is possible to shorten the labyrinth seal portion 370 on the low pressure side LP, where the leakage flow does not need to be reduced as much as on the high pressure side HP.

(5) The sealing device 450 of the fifth aspect is the sealing device 450 according to any one of (1) to (4), in which at least a portion of the plurality of labyrinth seal portions 470 has a diameter from the inner circumferential surface. A second fin portion 472 may be provided that protrudes inward in the direction and extends in the axis O direction.

According to this aspect, the seal device 450 can reduce swirl by causing the swirl to collide with the second fin portion 472. Thereby, the seal device 450 can reduce swirl even in the labyrinth seal portion 470.

(6) The seal device 450 of the sixth aspect extends along the axis O and is provided between the rotor 11 rotatable about the axis O and the stator 12 disposed on the outer peripheral side of the rotor 11. , a cylindrical sealing device 450 that covers the outer peripheral side of the rotor 11 and partitions the space between the rotor 11 and the stator 12 into a high pressure side HP and a low pressure side LP, A first fin portion 71 that projects inward in the radial direction and extends in the circumferential direction of the axis O, and a second fin portion 472 that projects inward in the radial direction from the inner peripheral surface and extends in the direction of the axis O are provided. A labyrinth seal portion 470 is provided.

(7) A rotating machine according to a seventh aspect includes a rotor 11 extending along an axis O and rotatable around the axis O, a stator 12 disposed on the outer peripheral side of the rotor 11, and a rotor 11 and the rotor 11. A cylindrical sealing device 50, 250, 350 provided between the rotor 12 and the stator 12 and covering the outer peripheral side of the rotor 11 and partitioning the space between the rotor 11 and the stator 12 into a high pressure side HP and a low pressure side LP. , 450, and the seal device 50, 250, 350, 450 includes a damper seal portion 60, 260 in which a plurality of holes 61 are provided on the inner peripheral surface, and the axis line of the damper seal portion 60, 260. A labyrinth seal portion 70, 270, 370 provided with a first fin portion 71 that is continuous with the low pressure side LP in the O direction, protrudes inward in the radial direction of the axis O from the inner circumferential surface, and extends in the circumferential direction of the axis O. , 470, and a plurality of the seal groups 50a are arranged in the direction of the axis O.
Examples of the rotating machine include a turbine 10 used in the gas turbine 1, a steam turbine, a compressor, and other large-sized rotating machines.

(8) A rotating machine according to an eighth aspect is the rotating machine according to (7), in which the rotor 11 includes a rotor-side fin portion 51 that projects outward in the radial direction from the outer peripheral surface and extends in the circumferential direction. The rotor-side fin portion 51 may be arranged adjacent to the first fin portion 71 in the axis O direction.

According to this aspect, the path of the fluid flowing through the labyrinth seal portions 70, 270, 370, and 470 can be made more complicated by the first fin portion 71 and the rotor-side fin portion 51. Thereby, the leakage flow reduction effect of the labyrinth seal portions 70, 270, 370, 470 can be increased.

1...Gas turbine 2...Compressor 3...Compressor rotor 4...Compressor casing 5...Compressor rotor blade stage 7...Compressor stationary blade stage 9...Combustor 10...Turbine (rotating machine) 11...Rotor 11a...Rotating shaft 12 ...Stator 13...Turbine stationary blade stage 14...Turbine stationary blade 15...Turbine casing 20...Turbine moving blade stage 30...Turbine moving blade 40...Retaining ring 42...Shroud 50...Seal device 50a...Seal group 51...Rotor side fin portion 60 ...Damper seal part 61...Hole part 62...First pocket fin part 63...Second pocket fin part 70...Labyrinth seal part 71...First fin part 250...Seal device 260...Damper seal part 270...Labyrinth seal part 350...Seal Device 370... Labyrinth seal part 450... Seal device 470... Labyrinth seal part 472... Second fin part G... Combustion gas (fluid) HP... High pressure side LP... Low pressure side O... Axis line P... Axial direction position V... Swirl flow velocity

Claims (8)

A rotor extending along an axis and rotatable around the axis, and a stator disposed on the outer peripheral side of the rotor, the space between the rotor and the stator being divided into a high pressure side and a low pressure side. A cylindrical sealing device that covers the outer peripheral side of the rotor,
a damper seal portion having a plurality of holes provided on an inner peripheral surface; and a damper seal portion that is continuous with the low pressure side of the damper seal portion in the axial direction, protrudes from the inner peripheral surface inward in the radial direction of the axis, and has a labyrinth seal portion provided with a first fin portion extending in the direction;
The seal group is a seal device in which a plurality of seal groups are provided in line in the axial direction. 2. The seal device according to claim 1, wherein the axial dimension of the damper seal section located on the highest pressure side in the axial direction is larger than the axial dimensions of the other damper seal sections. 3. The seal device according to claim 1, wherein the plurality of damper seal portions have a dimension in the axial direction that decreases from a high pressure side to a low pressure side in the axial direction. The seal device according to any one of claims 1 to 3, wherein the dimensions of the plurality of labyrinth seal portions in the axial direction decrease from the high pressure side to the low pressure side in the axial direction. According to any one of claims 1 to 4, at least a portion of the plurality of labyrinth seal portions is provided with a second fin portion that protrudes radially inward from the inner circumferential surface and extends in the axial direction. sealing device. A rotor extending along an axis and rotatable around the axis, and a stator disposed on the outer peripheral side of the rotor, the space between the rotor and the stator being divided into a high pressure side and a low pressure side. A cylindrical sealing device that covers the outer peripheral side of the rotor,
a first fin portion that projects radially inward from the inner circumferential surface of the axis and extends in the circumferential direction of the axis; a second fin portion that protrudes radially inward from the inner circumferential surface and extends in the axial direction; A sealing device comprising a labyrinth seal portion provided with a. a rotor extending along an axis and rotatable about the axis;
a stator disposed on the outer peripheral side of the rotor;
a cylindrical sealing device provided between the rotor and the stator, covering the outer peripheral side of the rotor and partitioning a space between the rotor and the stator into a high pressure side and a low pressure side;
Equipped with
The sealing device includes:
a damper seal portion having a plurality of holes provided on an inner peripheral surface; and a damper seal portion that is continuous with the low pressure side of the damper seal portion in the axial direction, protrudes from the inner peripheral surface inward in the radial direction of the axis, and has a labyrinth seal portion provided with a first fin portion extending in the direction;
The rotary machine includes a plurality of seal groups arranged in the axial direction. The rotor is provided with a rotor-side fin portion that protrudes outward in the radial direction from the outer circumferential surface and extends in the circumferential direction,
The rotating machine according to claim 7, wherein the rotor-side fin portion is arranged adjacent to the first fin portion in the axial direction.

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