JP2005016324A - Seal device and gas turbine - Google Patents

Abstract

A sealing device and a gas turbine that can cope with thermal deformation in a circumferential direction and a radial direction of a divided body and can improve sealing performance.
SOLUTION: Seal grooves 26a and 26b respectively provided in adjacent vane body segments 14 and 14 through a gap δc so as to face each other, and a seal member attached to the seal grooves 26a and 26b to seal the gap δc. 29, the sealing member 29 includes a rolling element connector 31 provided with substantially cylindrical rolling elements 30A and 30B on one side and the other side thereof, and the rolling elements 30A and 30B, respectively. And mounting bodies 33A and 33B having recessed rolling portions 32a and 32b fitted therein, and the mounting bodies 33A and 33B are slidable in the depth direction of the seal grooves 26a and 26b. In addition, the seal grooves 26a and 26b and the mounting bodies 33A and 33B are inserted into the corresponding seal grooves 26a and 26b so that the contact portions are in surface contact with each other.
[Selection] Figure 1

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device and a gas turbine for sealing gaps between a plurality of divided bodies that are thermally deformed.
[0002]
[Prior art]
In gas turbines, the working gas temperature is increased in order to improve the thermal efficiency, so that the stationary blades and moving blades arranged in the flow path (gas path) of the working gas can withstand this high temperature. Cooling is performed by introducing cooling air into the blade. The cooling method for this kind of gas turbine that is generally adopted is an open cooling method. The air extracted from the compressor is used as cooling air, and this cooling air is introduced into the blades from the casing side or turbine rotor side for cooling. To do. The cooling air after cooling the inside of the blade is discharged into the gas path by film cooling (film cooling) on the outer surface of the blade or as seal air for the wheel space.
[0003]
By the way, a stationary blade body or the like of a gas turbine (or a stationary blade diaphragm or a moving blade shroud) is composed of a plurality of divided bodies divided in the circumferential direction, and is adjacent to each other in consideration of thermal expansion deformation of these divided bodies. A circumferential gap is provided between the divided bodies so that the divided bodies do not contact each other even at the rated point. Therefore, when cooling air leaks into the gas path from such a gap, the leakage of the cooling air itself is an energy loss, the temperature of the working gas decreases due to dilution of the cooling air at a relatively low temperature, and the cooling air There was a risk of mixing loss due to mixing with the working gas, resulting in a decrease in turbine output.
[0004]
Accordingly, for example, a structure in which seal grooves are provided so as to face each other in adjacent divided bodies, and a so-called dockbone type seal member is attached to each of the opposed seal grooves to seal a circumferential gap. Has been proposed (see, for example, Patent Document 1). The dockbone type seal member has a thin central portion and a substantially arc-shaped cross section at the outer end. For example, when circumferential deformation (thermal elongation) occurs in two adjacent divided bodies, the seal member slides in the depth direction of the seal groove. When a thermal deformation difference (thermal elongation deviation) occurs, the outer end portion of the seal member rotates in the seal groove, and the seal member is inclined with respect to the seal groove.
[0005]
[Patent Document 1]
US Pat. No. 5,158,430 specification
[Problems to be solved by the invention]
However, the prior art has the following problems.
In other words, the outer end portion of the dock bone type seal member is formed in a substantially arc shape, so that the outer end portion and the seal groove are in contact with each other to slide or rotate. It was. Therefore, since the sealing surface is relatively small, the sealing performance is lowered, and the flow rate of the cooling air leaking into the gas path is increased.
[0007]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a sealing device and a gas that can cope with the thermal deformation in the circumferential direction and the radial direction of the divided body and can improve the sealing performance. It is to provide a turbine.
[0008]
[Means for Solving the Problems]
(1) In order to achieve the above-mentioned object, the present invention is mounted on at least one pair of seal grooves provided so as to face each other in two adjacent divided bodies through a gap, and these opposed seal grooves. In the sealing device including the sealing member for sealing the gap, the sealing member includes a rolling element connector provided with a convex rolling element on one side and the other side, and a convex shape on the one side and the other side. And a mounting body on one side and the other side, each having a concave rolling part fitted therein so that the rolling bodies can roll, and the mounting body on the one side and the other side of the seal member The seal groove is slidable in the depth direction, and is inserted into the corresponding seal groove so that the contact portion between the seal groove and the mounting body is in surface contact.
[0009]
For example, a stationary blade body or the like of a gas turbine is composed of a plurality of divided bodies divided in the circumferential direction, and seal grooves are respectively provided so as to face adjacent divided bodies through a gap. A seal member is attached to seal the gap.
[0010]
Here, in the present invention, the sealing member includes a rolling element connector provided with convex rolling elements on one side and the other side thereof, and one side and the other side on which the convex rolling elements are fitted so as to allow rolling. These mounting bodies are respectively inserted into the corresponding seal grooves. For example, when circumferential deformation (thermal elongation) occurs in two adjacent divided bodies (that is, the gap between the two adjacent divided bodies narrows), one side and the other side of the seal member are mounted. The body slides in the depth direction of the seal groove to respond. Further, for example, when a radial thermal deformation difference (thermal elongation deviation) occurs in two adjacent divided bodies (that is, the positional relationship between the two opposing seal grooves is shifted), the convex rolling element is attached to the mounting body. Since it is fitted so as to be able to roll, the convex rolling elements on one side and the other side roll in the concave rolling part of the mounting body, respectively, and the rolling element connector tilts with respect to the seal groove, so that the seal groove Corresponds to misalignment. Therefore, it can respond to the thermal deformation of the adjacent division body in the circumferential direction and radial direction.
[0011]
At this time, the mounting body slides in surface contact with the side surface of the seal groove, and the convex rolling element makes a line contact within the concave rolling portion of the mounting body and forms a minute gap before and after the rolling. Therefore, as compared with the case where the substantially arc-shaped end portion of the conventional dock bone type seal member is only in line contact with the seal groove, the seal surface and the fluid resistance are increased, and the seal performance can be improved.
[0012]
(2) In the above (1), preferably, the convex rolling element of the rolling element connector is a member subjected to a wear-resistant coating treatment.
[0013]
(3) In order to achieve the above object, the present invention also provides a compressor, a combustor, a turbine having stationary blades and moving blades, a plurality of divided bodies arranged in the turbine, and a gap. In a gas turbine comprising a seal groove provided to be adjacent to each of the adjacent divided bodies and a seal member that is mounted in the opposed seal groove and seals the gap, the seal member is on one side thereof And a rolling element connector provided with a convex rolling element on the other side, and a concave rolling part in which the convex rolling elements on the one side and the other side are fitted so as to be capable of rolling, respectively. And the mounting body on the other side, the mounting body on the one side and the other side of the seal member can slide in the depth direction of the seal groove, and the seal groove and the mounting body Make contact with the body surface contact It is fitted into the seal groove corresponding.
[0014]
(4) In order to achieve the above object, the present invention also provides a compressor, a combustor, a turbine having stationary blades and moving blades, a plurality of divided members arranged in the turbine, and a gap. In a gas turbine comprising a seal groove provided to be adjacent to each of the adjacent divided bodies and a seal member that is mounted in the opposed seal groove and seals the gap, the seal member is on one side thereof And a rolling element connector provided with a convex rolling element on the other side, and a concave rolling part in which the convex rolling elements on the one side and the other side are connected so as to be capable of rolling, respectively, and And a connecting portion between the convex rolling element and the concave rolling part is a fitting structure.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0016]
First, the overall configuration of the gas turbine according to the present embodiment, particularly the overall configuration from the flow of working gas and cooling air, will be described with reference to FIG. FIG. 2 is a diagram illustrating the overall configuration of an embodiment of the gas turbine of the present invention.
[0017]
In FIG. 2, a gas turbine 1 mainly includes a turbine 2, a compressor 3 connected to the turbine 2 to obtain compressed air for combustion, and compressed air from the compressed air 3 as a high-temperature high-pressure gas (working gas). The combustor 4 is converted into the following, and the turbine 2 is rotationally driven by the working gas from the combustor 4, and the generator 5 is configured to obtain electric power from the rotational energy.
[0018]
Since the later-described stationary blades and moving blades in the turbine 2 are heated to high temperatures by the working gas, the cooling air extracted from the compressor 3 passes through the stationary blade cooling air passages 6a and 6b and the moving blade cooling air passage 6c, and the turbine 2 It is supplied to the inner stationary blade and the moving blade. Since the cooling air is supplied at a pressure corresponding to the pressure of the working gas flow path (gas path) of the stationary blade, the stationary blade cooling air path 6a is extracted from the final stage (high pressure stage) of the compressor 3 and the stationary blade cooling air. The path 6b is configured to extract air from the intermediate pressure stage of the compressor 3. Further, the moving blade cooling air path 6 c is extracted from the final stage of the compressor 3. And the air which cooled the stationary blade and the moving blade in the turbine 2 is discharged | emitted in the gas path in the turbine 2, is mixed with working gas, and is discharge | released to air | atmosphere (what is called an open cooling system).
[0019]
FIG. 3 is a partial sectional view showing the detailed structure of the upstream two-stage portion of the turbine 2 according to the present embodiment. In FIG. 3, the working gas from the combustor 4 flows from the upstream side (left side in FIG. 3) to the downstream side (right side in FIG. 3).
[0020]
In FIG. 3, a turbine 2 includes a substantially cylindrical casing 7, first and second stage shrouds 8 a and 8 b provided annularly on the inner peripheral side (lower side in FIG. 3) of the casing 7, and these shrouds. First and second stage stationary blades 9a and 9b that are engaged and supported by 8a and 8b and provided in an annular shape, and first and second stage blades 10a and 10b that are annularly disposed between these stationary blades 9a and 9b, 10b and the turbine rotor 11 which provided these moving blades 10a and 10b in the outer peripheral side (upper side in FIG. 3). The stationary blades 9a and 9b accelerate the working gas from the combustor 4, and the turbine rotor 11 provided with the moving blades 10a and 10b is rotated by the working gas.
[0021]
The turbine rotor 11 includes first and second stage wheels 12a and 12b each having a first stage and second stage rotor blades 10a and 10b provided on the outer peripheral side, and a spacer sandwiched between the wheels 12a and 12b. 13.
[0022]
Next, taking the second stage stationary blade 9b as an example, the detailed structure and the flow of cooling air will be described. FIG. 4 is a cross-sectional view showing the detailed structure of the second stage stationary blade 9b. In FIG. 4, for convenience, a stator blade body segment described later is shown in a side view, and a cavity cover and a diaphragm described later are shown in a cross-sectional view.
[0023]
4 and FIG. 3 described above, the second stage stationary blade 9b includes a plurality of stationary blade body segments 14 that are divided in the circumferential direction and arranged annularly, and a diaphragm 15 that is attached to the inner circumferential side of these stationary blade body segments 14. And. The stationary blade body segment 14 includes an outer peripheral end wall 17 that forms an outer peripheral side of a working gas flow path (gas path) 16, an inner peripheral end wall 18 that forms an inner peripheral side of the gas path 16, and these end walls. The wing portion 19 is provided between the 17 and 18.
[0024]
A second stage stationary blade supply chamber 20 formed by the shrouds 8a and 8b and the outer end wall 17 is provided on the inner peripheral side of the casing 7, and the second stage stationary blade supply chamber 20 includes the stationary blade cooling air. Cooling air from the path 6b is supplied. In addition, a cooling air cavity 22 is formed on the outer peripheral side (upper side in FIG. 4) of the outer peripheral side end wall 17 so as to cover the cavity cover 21, and the cooling air cavity 22 is a vent hole of the cavity cover 21. Cooling air from the second stage stationary blade supply chamber 20 is introduced through (not shown). Then, cooling air from the cooling air cavity 22 is introduced into a cooling path (not shown) in the wing portion 19 to cool the wing portion 19, and then the air whose temperature has risen, for example, forms a film on the outer surface of the wing portion 19. While cooling (film cooling), the gas is discharged into the gas path 16.
[0025]
Further, part of the air in the cooling air cavity 22 passes through the diaphragm chamber 23 in the diaphragm 15, and the first stage rotor blade downstream wheel space formed by the first stage wheel 12 a, the spacer 13, and the diaphragm 15. 24a. A part of the air is flow-adjusted by the seal fin 25 that cooperates between the diaphragm 15 and the spacer 13, and the second stage formed by the second stage wheel 12 b, the spacer 13, and the diaphragm 15. It is introduced into the rotor blade upstream side wheel space 24b. At this time, the pressure in the wheel spaces 24a and 24b is higher than the pressure in the gas path 16, and the wheel spaces 24a and 24b are discharged into the gas path 16 as seal air.
[0026]
Next, an embodiment of the sealing device of the present invention applied to the adjacent stationary blade body segments 14, 14 will be described. FIG. 5 is an arrow view seen from the direction of arrow V in FIG. 4 and represents the overall structure of an embodiment of the sealing device of the present invention. FIG. 1 is a cross-sectional view taken along section II in FIG. .
[0027]
In FIGS. 5 and 1 and FIG. 4 described above, the adjacent stationary blade body segments 14 and 14 are arranged so that the stationary blade body segments 14 and 14 that have undergone thermal expansion deformation do not contact each other even at the rated point. A gap δc in the direction (vertical direction in FIG. 5) is provided. For this reason, as it is, the cooling air from the second stage stationary blade supply chamber 20 leaks into the gas path 16 (illustrated by an arrow A in FIG. 4), or from the first stage rotor blade downstream wheel space 24a. A leak flow path (illustrated by an arrow B in FIG. 4) is formed in which the sealed air leaks downstream of the gas path 16.
[0028]
Therefore, two pairs of seal grooves 26a and 26b and 27a and 27b (only 27a is shown in FIG. 4) are provided on the outer peripheral side end walls 17 and 17 of the adjacent stationary blade body segments 14 and 14 so as to face each other. A pair of seal grooves 28a and 28b (however, only 28a is shown in FIG. 4) are provided on the inner peripheral side end walls 18 and 18 of the adjacent stationary blade body segments 14 and 14 so as to face each other. Provided are seal members described later in these three pairs of seal grooves 26a, 26b, 27a, 27b, 28a, 28b, respectively, to suppress leakage from the gap δc.
[0029]
The seal member 29 mounted in the seal grooves 26a and 26b has a substantially cylindrical rolling element 30A on one side (the seal groove 26a side, the left side in FIG. 1) and the other side (the seal groove 26b side, the right side in FIG. 1). , 30B and a substantially flat rolling element connector 31 and a substantially flat mounting body having concave rolling portions 32a and 32b into which the rolling elements 30A and 30B are fitted so as to allow rolling. 33A, 33B. Thus, since the rolling elements 30A and 30B are fitted to the concave rolling portions 32a and 32b in the substantially flat mounting bodies 33A and 33B, respectively, the rolling elements 30A and 30B are fitted to the mounting bodies 33A. , 33B is not disengaged from the inside. Therefore, it is possible to cope with suppression of leakage and thermal deformation in the radial direction of the divided body. Further, the rolling elements 30A and 30B are connected to the concave rolling parts 32a and 32b, and the connecting part has a fitting structure.
[0030]
The mounting bodies 33A and 33B of the seal member 29 are inserted into the corresponding seal grooves 26a and 26b, respectively, while being slidable in the depth direction (left and right direction in FIG. 1) of the seal grooves 26a and 26b. The mounting bodies 33A and 33B have their outer peripheral side (upper side in FIG. 1) communicated with the second stage stationary blade supply chamber 20, and their inner peripheral side (lower side in FIG. 1) communicated with the gas path 16. A pressing force is applied to the inner peripheral side by the pressure difference (second stage stationary blade supply chamber 20 side pressure> gas path 16 side pressure), and the inner peripheral side surfaces (seal surfaces) 34a and 34b of the mounting bodies 33A and 33B are respectively sealed grooves 27a. , 27b is in surface contact with the side surface (lower side in FIG. 1). Further, the rolling elements 30A and 30B of the seal member 29 have sliding surfaces (seal surfaces) 35a and 35b which are in line contact with the rolling portions 32a and 32b, respectively, and a front and rear thereof form a minute gap. As a result, leakage from the gap δc is suppressed.
[0031]
The seal members attached to the seal grooves 27a and 27b and 28a and 28b have the same structure and configuration as the seal member 29, although not shown. As a result, leakage from the gap δc is suppressed.
[0032]
In addition, in the above, the stationary blade body segment 14 comprises the division body as described in each claim.
[0033]
Next, the operation and effect of this embodiment will be described.
The high-temperature and high-pressure working gas generated in the compressor 3 and the combustor 4 along with the operation of the gas turbine 1 has a pressure of about 2 MPa and a temperature of about 1400 ° C., and the first stage stationary blade 9 a and the first moving blade 10 a in the turbine 2. The pressure and temperature are reduced while turbine work is performed in each stage including the second stage stationary blade 9b and the second stage rotor blade 10b, and the final stage rotor blade flows out at about 600 ° C. Thereby, the turbine rotor 11 is rotationally driven, the rotational energy is converted, and the generator 5 obtains electric power. At this time, since the stationary blades 9a and 9b and the moving blades 10a and 10b in the turbine 2 are exposed to high-temperature working gas, the cooling air extracted from the compressor 3 is used as the stationary blade cooling air paths 6a and 6b and the moving blades. Supplyed via the blade cooling air path 6c, the metal temperature is reduced below the allowable temperature of the blade material.
[0034]
During the operation of the gas turbine 1, the plurality of stationary blade body segments 14 and the like arranged in an annular shape are heated and deformed through working gas and cooling air. FIG. 6 is a cross-sectional view showing the detailed structure of the seal member 29 when the adjacent stationary blade body segments 14 and 14 are thermally deformed.
[0035]
As shown in FIG. 6, thermal expansion in the circumferential direction (left and right direction in FIG. 6) occurred in the outer peripheral side end walls 17 and 17 of the adjacent stationary blade body segments 14 and 14 (that is, the circumferential gap δc was narrow). ), The mounting bodies 33A and 33B of the seal member 29 slide in the depth direction of the seal grooves 26a and 26b (26a on the left side and 26b on the right side in FIG. 6), respectively. Further, when a thermal expansion deviation δr in the radial direction (vertical direction in FIG. 6) occurs in the adjacent outer peripheral side end walls 17 and 17 (that is, the positional relationship between the opposing seal grooves 26a and 26b is shifted), the rolling elements 30A and 30B roll in the rolling portions 32a and 32b of the mounting bodies 33A and 33B (rotate counterclockwise in FIG. 6), and the rolling element connector 31 tilts with respect to the seal grooves 26a and 26b, thereby sealing grooves. This corresponds to the displacement of the positions 26a and 26b.
[0036]
As described above, in the present embodiment, it is possible to cope with the thermal deformation in the circumferential direction and the radial direction of the adjacent stationary blade body segments 14 and 14. At this time, the mounting bodies 33A and 33B of the seal member 29 slide while in surface contact with the side surfaces of the seal grooves 26a and 26b, and the rolling elements 30A and 30B are rolling portions 32a and 32b of the mounting bodies 33A and 33B. Rolling with a small gap between the inside and the line inside and behind, the seal surface and fluid resistance compared to the case where the substantially arcuate end of the conventional dock bone type seal member is only in line contact with the seal groove Increases, and the sealing performance can be improved.
[0037]
Further, when the rolling elements 30A and 30B of the seal member 29 roll for a long time in the rolling portions 32a and 32b of the mounting bodies 33A and 33B, the sliding surfaces of the rolling elements 30A and 30B and the rolling portions 32a and 32b are changed. Although it wears, the sliding surface becomes smooth by this wear (in other words, the space ratio on the surface roughness is reduced), and the sealing performance can be further improved. Further, the rolling elements 30A and 30B are made of a wear-resistant coating member, thereby improving the durability and smoothing the sliding surfaces of the rolling elements 30A and 30B in advance. Get the effect.
[0038]
Further, since the sealing member 29 has a structure in which the flat mounting bodies 33A and 33B are movably connected by the rolling element connector 31, for example, the sealing member 29 has its own thermal deformation difference as compared with a case where it is a substantially flat member having an integral structure. Alternatively, the occurrence of stress applied to the seal groove edge is prevented and damage and destruction are sufficiently prevented, so that the reliability can be improved.
[0039]
In the above-described embodiment, the stationary blade body segment 14 has been described as an example of the divided body. However, the present invention is not limited to this, and any member that is adjacent via a gap can be applied. That is, for example, the present invention may be applied to a divided body (diaphragm segment or shroud segment) in which the stationary blade diaphragm 15 or the moving blade shrouds 8a and 8b are divided in the circumferential direction. In this case, the same effect as described above can be obtained.
[0040]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, while being able to respond | correspond to the thermal deformation of the circumferential direction and radial direction of a division body, a sealing performance can be improved.
[Brief description of the drawings]
1 is a cross-sectional view taken along section II in FIG. 5 and shows a detailed structure of an embodiment of the sealing device of the present invention.
FIG. 2 is a diagram showing an overall configuration of an embodiment of a gas turbine of the present invention.
FIG. 3 is a partial cross-sectional view showing a detailed structure of an upstream two-stage portion of the turbine constituting one embodiment of the gas turbine of the present invention.
FIG. 4 is a sectional view showing a detailed structure of a second stage stationary blade constituting one embodiment of the gas turbine of the present invention.
FIG. 5 is an arrow view seen from the direction of arrow V in FIG. 4 and represents the overall structure of an embodiment of the sealing device of the present invention.
FIG. 6 is a cross-sectional view showing a detailed structure of an embodiment of the sealing device of the present invention, showing a state in which adjacent stationary blade body segments are thermally deformed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Turbine 3 Compressor 4 Combustor 9a First stage stationary blade 9b Second stage stationary blade 10a First stage moving blade 10b Second stage stationary blade 14 Stator blade body segment (divided body)
26a Seal groove 26b Seal groove 27a Seal groove 27b Seal groove 28a Seal groove 28b Seal groove 29 Seal member 30A Rolling body 30B Rolling body 31 Rolling body connector 32a Rolling portion 32b Rolling portion 33A Mounting body 33B Mounting body δc Gap

Claims (4)

In a sealing device comprising at least one pair of seal grooves provided to be opposed to each other in two divided bodies adjacent to each other via a gap, and a seal member that is mounted in these opposed seal grooves and seals the gap.
The seal member includes a rolling element connector provided with convex rolling elements on one side and the other side thereof, and a concave rolling element in which the convex rolling elements on the one side and the other side are fitted so as to be capable of rolling. And a mounting body on one side and the other side provided with a portion inside,
The mounting body on the one side and the other side of the seal member is slidable in the depth direction of the seal groove, and the contact portion between the seal groove and the mounting body is in surface contact, A seal device, wherein the seal device is inserted into the corresponding seal groove. The sealing device according to claim 1, wherein the convex rolling element of the rolling element connector is a member subjected to wear-resistant coating. A compressor, a combustor, a turbine having a stationary blade and a moving blade, a plurality of divided bodies arranged in the turbine, and seal grooves provided so as to be opposed to the adjacent divided bodies through a gap. And a gas turbine provided with a seal member that is mounted in these opposed seal grooves and seals the gap,
The seal member includes a rolling element connector provided with convex rolling elements on one side and the other side thereof, and a concave rolling element in which the convex rolling elements on the one side and the other side are fitted so as to be capable of rolling. And a mounting body on one side and the other side provided with a portion inside,
The mounting body on the one side and the other side of the seal member is slidable in the depth direction of the seal groove, and the contact portion between the seal groove and the mounting body is in surface contact, A gas turbine, wherein the gas turbine is inserted into the corresponding seal groove. A compressor, a combustor, a turbine having a stationary blade and a moving blade, a plurality of divided bodies arranged in the turbine, and seal grooves provided so as to be opposed to the adjacent divided bodies through a gap. And a gas turbine provided with a seal member that is mounted in these opposed seal grooves and seals the gap,
The seal member includes a rolling element connector provided with convex rolling elements on one side and the other side thereof, and a concave rolling part in which the convex rolling elements on the one side and the other side are connected so as to be capable of rolling. And a mounting body on one side and the other side provided inside,
A gas turbine characterized in that a connecting portion between the convex rolling element and the concave rolling portion has a fitting structure.

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