JP6209787B2 - Seal structure and rotating machine - Google Patents

Description

  The present invention relates to a seal structure and a rotary machine.

  In rotating machines such as steam turbines and gas turbines, forming a gap between the stationary side (casing) and the rotating side (blade) is an unavoidable measure for promoting smooth operation of the rotating machine. . On the other hand, leakage loss caused by leakage of working fluid such as steam or gas through the gap cannot be overlooked.

  A technique for forming a seal structure by providing a plurality of seal fins or the like extending radially inward from a casing is known as means for suppressing the above-described leakage loss in a rotating machine (for example, Patent Documents). 1).

By the way, in a rotating machine, self-excited vibration such as low-frequency vibration may occur. One of the causes of this self-excited vibration is the gas flow accompanied by the swirling flow generated in the region (cavity) defined between the seal fins.
The steam flow that has passed through the front stage of the seal fin contains a swirl component (circumferential velocity component), and this swirl component makes the pressure distribution in the circumferential direction in the cavity non-uniform. This is one of the causes.
Under the circumstances described above, a structure for reducing and attenuating swirl components is desired in the sealing mechanism of a rotary machine. On the other hand, for example, in the technique described in Patent Document 1, a leak jet having a component opposite to the swirl component is supplied into the cavity through the clearance of the seal fin.

JP 2010-159667 A

  However, with the technique described in Patent Document 1, it cannot be said that the effect of reducing the swirl component in the swirling flow is sufficient, and there is an increasing demand for a more effective seal structure.

  The present invention has been made to solve the above-described problem, and provides a seal structure that can more effectively reduce the swirling flow generated inside the cavity, and a rotary machine including the seal structure. For the purpose.

In order to solve the above problems, the present invention proposes the following means.
A seal structure according to an aspect of the present invention includes a rotor body that rotates about an axis, a rotor that includes a rotor blade that extends radially outward from the rotor body, and the rotor that covers the rotor from an outer peripheral side, and a tip of the rotor blade enters. A rotary machine seal structure including a casing having a cavity formed therein, extending from an inner peripheral surface of the cavity of the casing toward a tip of the moving blade, and forming a gap with the tip of the moving blade A seal fin is provided, and a penetrating portion penetrating in the axial direction is formed in the seal fin. The penetrating portion passes through the penetrating portion and fluid ejected to a section between the seal fins of the cavity. , The seal so as to collide with the flow toward the upstream side along the inner peripheral surface of the casing out of the vortex flow in the cavity based on the leak jet flowing through the gap Characterized in that it is formed in the root portion of the fin.

  According to this configuration, the flow having no swirl component that has passed through the through portion is mixed with the flow inside the cavity having a strong swirl component, so that the swirl component of the flow inside the cavity can be reduced.

  Further, in the seal structure according to one aspect of the present invention, the through portion extends in a direction opposite to the rotation direction of the steam turbine rotor from the upstream side through which the fluid flows along the axial direction toward the downstream side. Features.

  According to this configuration, the flow having the swirl component that goes in the direction opposite to the rotation direction of the steam turbine rotor that has passed through the through portion is mixed with the flow inside the cavity having the strong swirl component, so that the swirl can be more effectively performed. Components can be reduced.

Furthermore, the seal structure according to one aspect of the present invention includes a cylindrical portion inserted into the through portion.

  According to this configuration, the flow without the swirl component that has passed through the cylindrical portion is mixed with the flow inside the cavity having a strong swirl component, thereby reducing the swirl component of the flow inside the cavity. it can.

Furthermore, a seal structure according to an aspect of the present invention includes a rotor body that rotates about an axis, a rotor that includes a rotor blade that extends radially outward from the rotor body, and the rotor that covers the rotor from the outer peripheral side, and the tip of the rotor blade A rotary machine sealing structure including a casing formed with a cavity into which the cavity enters, extending from an inner peripheral surface of the cavity of the casing toward a tip of the moving blade, and having a gap with the tip of the moving blade A seal fin to be formed, and a penetrating portion penetrating in the axial direction is formed in the seal fin , provided at an outlet on the downstream side in the axial direction of the penetrating portion, toward the rear side in the rotational direction of the steam turbine rotor A guide portion is provided that protrudes and covers the outlet from the rotation direction side of the steam turbine rotor.

  According to this configuration, the flow having no swirl component that has passed through the through portion is deflected by the guide and mixed with the flow inside the cavity having a strong swirl component, so the swirl component of the flow inside the cavity Can be reduced.

  In the seal structure according to one embodiment of the present invention, a plurality of through portions are arranged along the circumferential direction of the seal fin.

  According to this configuration, since the through portions are arranged in the circumferential direction of the seal fin, the swirl component formed in the entire circumferential direction of the cavity can be reduced uniformly and effectively.

In addition, a seal structure according to an aspect of the present invention includes a rotor body that rotates about an axis, a rotor that includes a rotor blade that extends radially outward from the rotor body, and the rotor that covers the rotor from an outer peripheral side, and the tip of the rotor blade A rotary machine sealing structure including a casing formed with a cavity into which the cavity enters, extending from an inner peripheral surface of the cavity of the casing toward a tip of the moving blade, and having a gap with the tip of the moving blade A seal fin to be formed, and a through portion penetrating in the axial direction is formed in the seal fin, and a plurality of the seal fins arranged in the axial direction are provided on the inner peripheral surface of the cavity. , each of the through portion provided in a plurality of the seal fins adjacent to each other, characterized in that it is formed radially offset from each other when viewed from the axial direction

According to this configuration, by providing a plurality of seal fins, the multiplicity of the sealing effect can be increased, leakage of the working fluid can be more effectively reduced, and leakage loss as a rotating machine can be reduced.
In addition, by providing a through portion in each seal fin, the swirl component formed on the downstream side in the axial direction can be more effectively reduced.
Furthermore, the working fluid that passes through the through portion formed in the upstream seal fin does not directly flow into the through portion formed in the adjacent downstream seal fin. Therefore, the expression of the blow-through effect generated between the upstream penetrating portion and the downstream penetrating portion is reduced, so that leakage loss due to leakage of the working fluid can be effectively suppressed.

  In the seal structure according to one aspect of the present invention, the through portions provided in the plurality of adjacent seal fins are formed so as to be shifted from each other in the circumferential direction when viewed from the axial direction.

  According to this configuration, the working fluid that passes through the through portion formed in the upstream seal fin does not directly flow into the through portion formed in the adjacent downstream seal fin. Therefore, the expression of the blow-through effect that occurs between the upstream side penetration and the downstream side penetration is reduced. Further, the leakage performance due to the leakage of the working fluid can be effectively suppressed by improving the sealing performance.

  A rotating machine according to an aspect of the present invention includes a rotor body that rotates about an axis, a rotor having a moving blade that extends radially outward from the rotor body, and the rotor that covers the rotor from an outer peripheral side, and a tip of the moving blade enters It is characterized by comprising a casing in which a cavity is formed and any one of the above sealing structures.

  According to the seal structure and the rotating machine of the present invention, the swirl component inside the cavity can be reduced.

1 is a schematic diagram of a steam turbine according to the present invention. It is a principal part expanded sectional view of the steam turbine which concerns on this invention. It is a principal part enlarged view which shows the cavity periphery of the steam turbine which concerns on this invention. It is the figure which looked at the seal fin which concerns on 1st embodiment of this invention from the radial direction outer side. It is the figure which looked at the seal fin which concerns on 2nd embodiment of this invention from the radial direction outer side. It is a figure which shows the modification of 2nd embodiment of this invention. It is the figure which looked at the seal fin which concerns on 3rd embodiment of this invention from the radial direction outer side. It is a figure which shows the modification of 3rd embodiment of this invention. It is the figure which looked at the seal fin which concerns on 4th embodiment of this invention from the radial direction outer side. It is the figure which looked at the seal fin which concerns on 5th embodiment of this invention from the radial direction outer side. It is a figure which shows the modification of 5th embodiment of this invention. It is a figure which shows the modification of 5th embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
First, in the first embodiment of the present invention, a steam turbine 1 which is a rotating machine will be described with reference to FIG.
As shown in FIG. 1, a steam turbine plant 100 includes a rotor body 11 that rotates about an axis O, a steam turbine rotor 3 connected to the rotor body 11, and steam S as a working fluid. A steam supply pipe 12 that supplies the steam turbine 1 from the figure and a steam discharge pipe 13 that is connected to the downstream side of the steam turbine 1 and discharges the steam.

  In FIG. 1, the side where the steam supply pipe 12 is located is called the upstream side, and the side where the steam discharge pipe 13 is located is called the downstream side, and the following description will be made accordingly.

  As shown in FIG. 1, the steam turbine 1 is capable of rotating a steam turbine rotor 3 extending along the direction of the axis O, a steam turbine casing 2 that covers the steam turbine rotor 3 from the outer peripheral side, and a rotor body 11 about the axis O. And a bearing portion 4 to be supported.

  The steam turbine rotor 3 includes a plurality of moving blades 31. The moving blade 31 is provided so as to protrude radially outward from the outer surface of the steam turbine rotor 3. Furthermore, a plurality of moving blades 31 are arranged at regular intervals in the circumferential direction of the steam turbine rotor 3. Similarly, in the direction of the axis O, a plurality of rows of moving blades 31 are arranged with a constant interval. The moving blade 31 is a member having a blade-shaped cross section when viewed from the radial direction. Further, a blade tip shroud 34 is provided at the tip end portion (radially outer end portion) of the blade 31.

  The steam turbine casing 2 is a substantially cylindrical member provided so as to cover the steam turbine rotor 3 from the outer peripheral side. Further, a plurality of stationary blades 21 are provided along the inner peripheral surface 25 of the steam turbine casing 2. The stationary blade 21 is a blade-like member connected to the inner peripheral surface 25 of the steam turbine casing 2 via the stationary blade base 24. Further, a stationary blade hub shroud 22 is provided at a tip portion (a radially inner end portion) of the stationary blade 21. Similar to the moving blade 31, a plurality of stationary blades 21 are arranged along the circumferential direction of the inner peripheral surface 25 and the direction of the axis O. Further, the moving blade 31 is arranged so as to enter the region between the plurality of adjacent stationary blades 21.

In the steam turbine casing 2, a region where the stationary blades 21 and the moving blades 31 are arranged forms a main flow path 20 through which the steam S that is a working fluid flows.
Furthermore, a space is formed between the inner peripheral surface 25 of the steam turbine casing 2 and the blade tip shroud 34, and this space is referred to as a cavity 50.

  The main steam S1 is supplied to the steam turbine 1 configured as described above through the upstream steam supply pipe 12. Thereafter, as the steam turbine rotor 3 rotates, it passes through the row of the stationary blades 21 and the moving blades 31 and is eventually discharged toward the subsequent device (not shown) through the downstream steam discharge pipe 13. Here, when passing through the row of the stationary blade 21 and the moving blade 31, the steam S also flows into the cavity 50 described above.

FIG. 3 is an enlarged view of the periphery of the cavity 50. The cavity 50 is provided with seal fins (seal structure) 40. The seal fin 40 is an annular member that protrudes radially inward from the inner peripheral surface 25 of the steam turbine casing 2. More specifically, the seal fin 40 protrudes from the inner peripheral surface 25 of the casing 2 so as to have a shape in which the thickness in the axis O direction gradually decreases from the radially outer side toward the radially inner side. In the present embodiment, three rows of seal fins 40 are arranged inside the cavity 50 along the axis O direction.
A region surrounded by the main flow path 20 and the seal fin 40 located on the most upstream side forms an inflow section 51. Further, on the downstream side of the inflow section 51, the first section 52 is formed by the adjacent seal fins 40.

  In addition, the radially inner tip of the seal fin 40 faces the outer surface 35 of the rotor blade tip shroud 34 with a minute gap m therebetween. The dimension of the gap m in the radial direction of the steam turbine rotor 3 is determined in consideration of the thermal expansion amount of the steam turbine casing 2, the moving blade 31, the centrifugal extension amount of the moving blade 31, and the like. 34 is determined in a range where it does not come into contact with 34.

  In the present embodiment, a through portion 41 is formed in the seal fin 40. The penetrating portion 41 is a through-hole penetrating the seal fin 40 in the direction of the axis O, and is formed at the root portion of the seal fin 40 (portion close to the steam turbine casing 2). As shown in FIG. 3, the penetrating portion 41 is provided in parallel with the inner peripheral surface 25 of the steam turbine casing 2 and the outer surface 35 of the rotor blade tip shroud 34 in a cross-sectional view.

  FIG. 4 is a view showing the cavity 50 viewed from the outside in the radial direction of the steam turbine rotor 3. As shown in FIG. 5, the penetrating portion 41 in the present embodiment is formed in parallel with the axis O even when viewed from the radial outside of the steam turbine rotor 3. Further, a plurality of through portions 41 are arranged at a constant interval over the circumferential direction of the seal fin 40. Note that an arrow R in FIG. 4 represents the direction in which the steam turbine rotor 3 rotates.

Next, with reference to FIGS. 3 to 5, the operation of the steam turbine 1 in the present embodiment will be described.
In the steam turbine plant 100 described above, the steam S from the steam supply source is supplied to the steam turbine 1 via the steam supply pipe 12.
The steam S supplied to the steam turbine 1 reaches the main flow path 20. The steam S that has reached the main flow path 20 circulates toward the downstream side while repeating expansion and flow diversion as it flows through the main flow path 20. Since the moving blade 31 has an airfoil cross section, the steam turbine rotor 3 rotates when the steam S collides with the moving blade 31 or receives a reaction force when the steam expands inside the moving blade 31. Thereby, the energy of the steam S is taken out as the rotational power of the steam turbine 1.

The operation of the steam S flowing through the main channel 20 in the above process will be described in more detail with reference to FIGS.
FIG. 2 is an enlarged view of the periphery of the cavity 50. As shown in FIG. 2, the steam S that has flowed into the main flow path 20 passes through the stationary blade 21 and then is divided into a main steam flow SM and a deflected steam flow SL. The main steam flow SM is introduced into the moving blade 31 without being deflected.
The deflected steam flow SL flows into the inflow section 51 through the space between the blade tip shroud 34 and the steam turbine casing 2. Here, after the steam S passes through the stationary blade 21, the swirl component (circumferential velocity component) is increased, and a part of the steam S is separated and flows into the inflow section 51 as a deflected steam flow SL. . Therefore, the deflected steam flow SL also includes a swirl component like the steam S.
And the deflection | deviation vapor | steam flow SL which flowed into the inflow division 51 is divided | segmented into the leak jet SL1 which flows toward the gap | interval m, and the penetration vapor | steam flow SL2 which flows toward the penetration part 41, as shown in FIG. Like the deflected steam flow SL, the leak jet SL1 and the through steam flow SL2 also include a swirl component.

  The leak jet SL1 flowing toward the gap m passes through the gap m through the inflow section 51 and flows into the first section 52. The leak jet SL1 that has flowed into the first section 52 flows downstream along the outer surface 35 of the blade tip shroud 34 in the axis O direction. The leak jet SL1 that has flowed downstream in the direction of the axis O collides with the downstream seal fin 40, changes its direction, and flows toward the inner peripheral surface 25 of the steam turbine casing 2. Thereafter, the leak jet SL1 collides with the inner peripheral surface 25 of the steam turbine casing 2 and changes its direction again, and flows toward the upstream side in the axis O direction in the vicinity of the inner peripheral surface 25. As a result, the leak jet SL1 that has flowed into the first section 52 becomes a vortex flow SS containing a component that rotates counterclockwise in the plane of the drawing shown in FIG.

  Further, the leak jet SL1 still contains a swirl component even after passing through the gap m and flowing into the first section 52. Therefore, as shown in FIG. 4, the leak jet SL <b> 1 becomes a swirl flow toward the rotation direction R of the steam turbine rotor 3 as it goes downstream in the first section 52.

  On the other hand, the penetrating vapor flow SL2 flows into the first section 52 from the penetrating portion 41. The through steam flow SL2 flowing into the first section 52 from the through portion 41 is ejected downstream along the direction of the axis O in which the through portion 41 extends, and is mixed with the leak jet SL1 as a swirling flow. Here, since the through vapor flow SL2 passes through the through portion 41, it does not include a swirl component. That is, the through-vapor flow SL2 that does not include a swirl component is mixed with the leak jet SL1 that is a swirl flow that includes a strong swirl component. Then, the swirl component of the leak jet SL1 is reduced by mixing the leak jet SL1 and the through vapor flow SL2. Thereby, the swirl | vortex flow which induces the self-excited vibration which arises in the steam turbine 2 is suppressed.

  Further, as shown in FIG. 3, the through steam flow SL <b> 2 that has flowed into the first section 52 from the through portion 41 is located in the vicinity of the inner peripheral surface 25 in the vicinity of the inner peripheral surface 25 of the steam turbine casing 2, upstream in the axis O direction. It collides with the vortex flow SS that flows toward. That is, in the vicinity of the inner peripheral surface 25 of the steam turbine casing 2, the vortex flow SS flows toward the upstream side (left side in FIG. 3). The vapor flow SL2 collides with the vortex flow SS. As a result, the vortex flow SS is weakened.

  Here, when the vortex flow SS is strong, the effect of blowing through the gap m of the leak jet SL1 is increased, and the static pressure inside the vortex flow SS is reduced, so that the differential pressure before and after the seal fin 40 is increased. End up. On the other hand, in this embodiment, since the vortex flow SS is weakened by the through-vapor flow SL2, an increase in the blow-through effect of the leak jet SL1 can be reduced, and an increase in the differential pressure across the seal fin 40 is suppressed. be able to.

(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the component similar to 1st embodiment, and detailed description is abbreviate | omitted.
FIG. 5 is a view showing the cavity 50 viewed from the outside in the radial direction of the steam turbine rotor 3 in the second embodiment of the present invention.
In the present embodiment, the through portion 42 provided in the seal fin 40 extends in the direction opposite to the rotation direction R of the steam turbine rotor 3 from the upstream side in the axis O direction toward the downstream side. In other words, when viewed from the outside in the radial direction of the steam turbine rotor 3, the through portion 42 extends obliquely with a constant angle with respect to the axis O.

  According to the above-described configuration, the through steam flow SL <b> 2 with the swirl component directed in the direction opposite to the rotation direction R of the steam turbine rotor 3 (the swirl component direction in the swirl flow of the leak jet SL <b> 1) is ejected into the first section 52. And mixed with the leak jet SL1. Therefore, a part of the swirl component in the swirling flow of the leak jet SL1 can be canceled out. Thereby, the self-excited vibration generated in the steam turbine 2 can be further suppressed.

  Next, a modification in the present embodiment will be described with reference to FIG. In FIG. 6, the through portion 43 provided in the seal fin 40 is formed to be gradually curved from the upstream side in the axis O direction toward the downstream side. In other words, the inlet 43A of the penetrating portion 43 is provided at a gentle angle with respect to the penetrating steam flow SL2. Therefore, the through vapor flow SL2 can be more efficiently captured by the through portion 43, and the through vapor flow SL2 can be stably supplied.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the component similar to each above-mentioned embodiment, and detailed description is abbreviate | omitted.
FIG. 7 is a view showing the cavity 50 viewed from the outside in the radial direction of the steam turbine rotor 3 in the third embodiment of the present invention.
In the present embodiment, the through portion 44 is formed by a cylindrical portion 44T inserted into the seal fin 40. The cylindrical portion 44T is a cylindrical member formed of the same material as that of the seal fin 40, for example, and has a through-hole penetrating in the axial direction. Further, as in the second embodiment, the penetrating portion 44 extends in a direction opposite to the rotation direction R of the steam turbine rotor 3 from the upstream side toward the downstream side in the axis O direction.

  According to the above-described configuration, the through steam flow SL <b> 2 with the swirl component directed in the direction opposite to the rotation direction R of the steam turbine rotor 3 (the swirl component direction in the swirl flow of the leak jet SL <b> 1) is ejected into the first section 52. And mixed with the leak jet SL1. Therefore, as in the second embodiment, part of the swirl component in the swirling flow of the leak jet SL1 can be canceled, and the self-excited vibration generated in the steam turbine 2 can be further suppressed.

  Next, a modification in the present embodiment will be described with reference to FIG. In the present embodiment, the cylindrical portion 45T forming the penetrating portion 45 is formed to be gradually curved from the upstream side in the axis O direction toward the downstream side. In other words, the inlet 45A of the penetrating portion 45 is provided at a gentle angle with respect to the penetrating steam flow SL2. Therefore, the through vapor flow SL2 can be more efficiently captured by the through portion 45, and the through vapor flow SL2 is stably supplied.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the component similar to each above-mentioned embodiment, and detailed description is abbreviate | omitted.
FIG. 9 is a view showing the cavity 50 viewed from the outside in the radial direction of the steam turbine rotor 3 in the fourth embodiment of the present invention.
In the present embodiment, the rotation direction R of the steam turbine rotor 3 from the outlet 46B located downstream of the penetrating portion 46 in the axis O direction to the downstream outlet of the penetrating portion 46 formed along the axis O direction in the seal fin 40. The guide part 46W which protrudes toward the opposite direction is further provided. The guide portion 46 </ b> W is provided so as to cover the outlet 46 </ b> B of the penetrating portion 46 from the rotation direction R side of the steam turbine rotor 3.

  According to the above-described configuration, the through steam flow SL <b> 2 with the swirl component directed in the direction opposite to the rotation direction R of the steam turbine rotor 3 (the swirl component direction in the swirl flow of the leak jet SL <b> 1) is ejected into the first section 52. And mixed with the leak jet SL1. Therefore, as in the second and third embodiments, a part of the swirl component in the swirling flow of the leak jet SL1 can be canceled, and the self-excited vibration generated in the steam turbine 2 can be further suppressed.

(Fifth embodiment)
Furthermore, a fifth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the component similar to each above-mentioned embodiment, and detailed description is abbreviate | omitted.
FIG. 10 is a view showing the upstream side seal fin 40F and the downstream side seal fin 40R viewed from the upstream side in the axis O direction of the steam turbine rotor 3, respectively. Both the upstream-side seal fin 40F and the downstream-side seal fin 40R are arranged along the axis O with a constant interval.

Upstream through portions 47F are arranged at equal intervals along the circumferential direction in the upstream seal fin 40F. Similarly, downstream through-holes 47R are arranged at equal intervals along the circumferential direction in the downstream seal fin 40R.
Here, as shown in FIG. 10, the upstream penetrating portion 47F and the downstream penetrating portion 47R are arranged with different phases in the circumferential direction when viewed from the direction of the axis O.
Therefore, the through steam flow SL2 that has passed through the upstream through portion 47F does not blow through the downstream through portion 47R directly.

  With such a configuration, in addition to the effect of suppressing self-excited vibrations by the same action as in the above-described embodiments, the effect of blowing through the steam flow SL2 that has passed through the upstream through part 47F is suppressed, so that the sealing effect The steam leakage in the cavity 50 can be more effectively reduced.

In this embodiment, the upstream penetrating portion 47F and the downstream penetrating portion 47R are arranged with different phases in the circumferential direction. However, as shown in FIGS. 11 and 12, the phase may be shifted in the radial direction, The phase may be different in both the circumferential direction and the radial direction.
Even in such a configuration, in addition to the suppression effect of the self-excited vibration, the blow-through effect of the through steam flow SL2 that has passed through the upstream through portions 48F and 49F is suppressed, so that the sealing effect is improved and the steam leakage is further improved. It can be effectively reduced.

DESCRIPTION OF SYMBOLS 1 ... Steam turbine 2 ... Steam turbine casing 3 ... Steam turbine rotor 4 ... Bearing part 20 ... Main flow path 21 ... Stator blade 22 ... Stator blade hub shroud 31 ... Rotor blade 34 ... Rotor blade tip shroud 40 ... Seal fin (seal structure)
41 ... penetrating part 50 ... cavity S ... steam SL ... deflection steam flow SL1 ... leak jet SL2 ... penetrating steam flow SS ... vortex flow

Claims (8)

A rotary machine comprising: a rotor body that rotates about an axis; a rotor having a rotor blade that extends radially outward from the rotor body; and a casing that covers the rotor from an outer peripheral side and has a cavity into which a tip of the rotor blade enters. The sealing structure of
A seal fin that extends from the inner peripheral surface of the cavity of the casing toward the tip of the rotor blade and forms a gap with the tip of the rotor blade,
A penetrating portion penetrating in the axial direction is formed in the seal fin ,
The penetrating portion is an inner peripheral surface of the casing of a vortex flow in the cavity based on a leak jet in which a fluid that passes through the penetrating portion and is ejected to a section between the seal fins of the cavity flows through the gap. A seal structure , wherein the seal fin is formed at the base of the seal fin so as to collide with the flow toward the upstream side . A rotary machine comprising: a rotor body that rotates about an axis; a rotor having a rotor blade that extends radially outward from the rotor body; and a casing that covers the rotor from an outer peripheral side and has a cavity into which a tip of the rotor blade enters. The sealing structure of
A seal fin that extends from the inner peripheral surface of the cavity of the casing toward the tip of the rotor blade and forms a gap with the tip of the rotor blade,
A penetrating portion penetrating in the axial direction is formed in the seal fin,
A plurality of the seal fins arranged along the axial direction on the inner peripheral surface of the cavity;
The through portions provided in the plurality of adjacent seal fins are formed so as to be shifted in the radial direction from each other when viewed from the axial direction.
A seal structure characterized by that. The seal structure according to claim 2 , wherein the through portions provided in the plurality of seal fins adjacent to each other are formed to be shifted from each other in the circumferential direction when viewed from the axial direction. The through portion, toward the downstream side from the upstream side to the flow of fluid in the axial direction, any one of claims 1 to 3, characterized in that extending toward the rotation direction opposite to the direction of the rotor The seal structure described in 1. The seal structure according to any one of claims 1 to 4, further comprising a cylindrical portion inserted into the penetrating portion. A rotary machine comprising: a rotor body that rotates about an axis; a rotor having a rotor blade that extends radially outward from the rotor body; and a casing that covers the rotor from an outer peripheral side and has a cavity into which a tip of the rotor blade enters. The sealing structure of
  A seal fin that extends from the inner peripheral surface of the cavity of the casing toward the tip of the rotor blade and forms a gap with the tip of the rotor blade,
A penetrating portion penetrating in the axial direction is formed in the seal fin,
Provided at an outlet on the downstream side in the axial direction of the penetrating portion and protruding in a direction opposite to the rotation direction of the rotor and covering the outlet from the rotation direction side of the rotor
A seal structure characterized by that. The seal structure according to any one of claims 1 to 6 , wherein a plurality of the through portions are arranged along a circumferential direction of the seal fin. A rotor body that rotates about an axis and a rotor blade that extends radially outward from the rotor body;
A casing that covers the rotor from the outer peripheral side, and in which a cavity into which the tip of the moving blade enters is formed,
A rotary machine comprising the seal structure according to any one of claims 1 to 7 .

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