JP2009203948A - Seal device, seal method and gas turbine having seal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve seal performance by reducing a leak quantity from a clearance, by restraining generation of the clearance of a butting part of a seal plate. <P>SOLUTION: A seal device is provided for shielding a high pressure part and a low pressure part by connecting a plurality of members having a first seal groove 31 extending in a straight line shape, a second seal groove 33 extending in a straight line shape by branching off from the first seal groove 31, a first seal plate 41 installed in the first seal groove 31, and a second seal plate 43 installed in the second seal groove 33, on respective opposed surfaces of a connecting part of the plurality of connected members, and has a deformable member 50 in the butting part of the first seal plate 41 and the second seal plate 43 so as to reduce the clearance between the first seal plate 41 and the second seal plate 43. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sealing device, a sealing method, and a gas turbine having the sealing device.

  Patent Document 1 discloses a technique for performing gas sealing on a single face clearance of a stationary blade segment of a gas turbine by combining a seal plate installed approximately horizontally and a seal plate installed approximately perpendicular to the seal plate. Yes.

JP-A-11-200809

  However, in such a technique, there is a possibility that a gap is generated in the abutting portion of the seal plate, and the required amount of seal air is increased.

  An object of the present invention is to reduce the amount of leakage from the gap and improve the sealing performance by suppressing the occurrence of a gap in the butt portion of the seal plate.

  A first seal groove extending linearly, a second seal groove extending from the first seal groove and extending linearly on each opposing surface of the connecting portions of the plurality of connected members, and the first A seal device for connecting a plurality of members having a first seal plate mounted in one seal groove and a second seal plate mounted in the second seal groove to shield the high pressure portion and the low pressure portion And a member deformable so as to reduce a gap between the first seal plate and the second seal plate at a butting portion between the first seal plate and the second seal plate.

  According to the present invention, it is possible to provide a sealing device, a sealing method, and a gas turbine having a sealing device that reduce the amount of leakage from the gap and improve the sealing performance by suppressing the generation of the gap at the butt portion of the sealing plate. .

  FIG. 2 shows a configuration diagram of the gas turbine. The illustrated gas turbine 1 mainly obtains shaft power by a compressor 2 that generates compressed air for combustion, a combustor 3 that combusts compressed air from the compressor 2 together with fuel, and combustion gas from the combustor 3. A turbine 4 is provided. The shaft power obtained by the turbine 4 is used as driving force for the compressor 2 and the generator 5. Moreover, although the case where the generator 5 is used as a load apparatus is mentioned as an example, a pump, another compressor, etc. may be driven with the obtained shaft power. In an example of the operating state of the gas turbine 1, the high-temperature mainstream gas 6 generated in the combustor 3 has a pressure of about 1.2 MPa and a temperature of about 1200 ° C. when flowing into the turbine 4. Thereafter, the pressure and temperature are reduced while performing expansion work inside the turbine, and the gas is discharged through the final stage blade at about 600 ° C.

  In the turbine 4, the member exposed to the high-temperature mainstream gas 6 is cooled to a temperature lower than the allowable temperature by low-temperature air so that the member does not melt or crack due to oxidation or thermal stress. . Hereinafter, such air is referred to as cooling air. In general, the cooling air is extracted from the compressor 2.

  FIG. 3 is a cross-sectional view showing the internal structure of the turbine 4 in the vicinity of the front-stage stationary vane. The mainstream gas 6 that has passed through the transition piece 10 passes through the first stage stationary blade 11, the first stage stationary blade 12, the second stage stationary blade 13, and the second stage stationary blade 14 and is guided to the subsequent stage stationary stationary blade. The first stage vane 11 is connected to the casing 8 via the retainer ring 9 on the outer peripheral side, and is connected to the support ring 17 on the inner diameter side. The first stage rotor blade 12 and the second stage rotor blade 14 are fixed to a turbine wheel 18 and rotate at a high speed during operation of the gas turbine. The first stage blade shroud 15 and the second stage blade shroud 16 are respectively fixed to the casing 8 to suppress the mainstream gas 6 from bypassing the outer diameter side of the blades 12 and 14. The second stage stationary blade 13 is fixed to the shrouds 15 and 16 on the outer peripheral side. In addition, a diaphragm 19 is provided on the inner periphery of the second stage stationary blade 13, and the mainstream gas 6 is prevented from bypassing the turbine wheel 18 and the inner periphery side of the second stage stationary blade 13.

  The air extracted from the compressor 2 is used as the cooling air 7a for cooling the first stage stationary blade 11 and the cooling air 7b for cooling the second stage stationary blade 13 (the supply system is not shown). Cooling air for cooling the moving blades 12 and 14 and the moving and stationary blades on the rear stage is also extracted from the compressor 2 and supplied to the turbine cooled portion (not shown). At this time, the cooling air is set to a pressure corresponding to the gas path pressure of each blade. For example, the first stage stationary blade cooling air 7a is extracted in the vicinity of the compressor final stage, and the second stage stationary blade cooling air 7b is compressed. Extracted air at an intermediate pressure stage is used. And the cooling air after cooling a to-be-cooled part is discharge | released in the mainstream gas 6 of a turbine, is mixed, and is discharge | released to air | atmosphere.

  The turbine 4 is constituted by a member divided into a plurality of parts so as to alleviate stress concentration due to thermal deformation of the member and facilitate inspection, maintenance, and replacement of parts. In such a gas turbine, a fluid having a pressure higher than that of the mainstream gas and lower than that of the mainstream gas is supplied to the outside of the member so that the high-temperature mainstream gas does not leak out of the gap between the members. Hereinafter, such a fluid is referred to as seal air. Generally, in a gas turbine, the sealing air uses a part of the cooling air. However, if the flow rate of the sealing air is increased unnecessarily, the temperature of the high-temperature mainstream gas that drives the turbine and cooling air are mixed. The mixing loss that occurs sometimes is increased, and the efficiency of the entire gas turbine is reduced.

  Therefore, a seal structure is taken between adjacent members. Mainly, there is a technique to suppress the increase in the flow rate of the seal air by spanning the seal plate over the seal grooves provided on the surfaces of the stationary members facing each other and reducing the flow passage area through which the seal air leaks. It is taken.

  FIG. 4 shows the first-stage stationary blade segments 11a, 11b, and 11c adjacent to each other in an annular shape when the AA cross section of FIG. 3 is viewed from the upstream direction of the mainstream gas. The first stage stator vane segments 11a, 11b, and 11c have a structure having outer diameter side end walls 21a, 21b, and 21c and inner diameter side end walls 22a, 22b, and 22c, respectively. In adjacent segments, a seal plate 41 is stretched over the outer diameter side, and a seal plate 42 is stretched over the inner diameter side. FIG. 5 is a view of the first-stage stationary blade segments 11a, 11b, and 11c, which are adjacent constituent members, viewed from the outside in the turbine radial direction. The outer diameter side end wall 21a of the first stage stationary blade segment 11a and the outer diameter side end wall 21b of the first stage stationary blade segment 11b face each other in parallel, and a circumferential gap σc is provided between them. Assembled. The outer diameter side end wall 21a of the first stage stationary blade segment 11a and the outer diameter side end wall 21b of the first stage stationary blade segment 11b are opposed to each other on the opposing end surfaces of the adjacent end walls 21a, 21b. Are provided with seal grooves 31a and 31b. In these opposing seal grooves 31a and 31b, a seal plate 41 is installed so as to bridge the circumferential gap between the end walls 21a and 21b, and the gap σc between the constituent members is sealed. It has become.

  Normally, this seal location is sealed by a linearly shaped seal plate at a position close to the gas path of the stationary member exposed to the hot working gas so that the hot mainstream gas does not leak outside the gas path. The high pressure part and the low pressure part are shielded. Further, since a gap between radial members is generated in the hook portion for fixing the stationary member to the retainer ring 9, the high pressure portion and the low pressure portion are shielded by another seal plate.

  FIG. 6 shows a cross-sectional view of the first stage stationary blade segment adjacent surface. Taking the first stage stationary blade 11 shown in FIG. 6 as an example, on the outer diameter side, a first seal plate 41 is provided in the first seal groove 31 extending in the outer diameter side end wall 21 in the turbine axial direction. Is installed to shield the gap between the outer diameter side end wall portions, and the second seal plate 43 is installed in the seal groove 33 extending in the turbine radial direction in the outer diameter side hook 23 to shield the gap between the hook portions. . Also on the inner diameter side, a first seal plate 42 is provided in a seal groove 32 extending in the turbine axial direction in the inner diameter side end wall 22 of the first stage stationary blade 11 to shield the gap between the inner diameter side end wall portions, A second seal plate 44 is housed in a seal groove 34 extending in the turbine radial direction in the inner diameter side hook 24 to shield the gap between the inner diameter side hook portions.

  FIG. 7 is a detailed view of the seal plate butting portion in which the portion B in FIG. 6 is enlarged. In the above technique, as shown in FIG. 7, there is a possibility that a gap δs is generated at the abutting portion between the first seal plate 41 and the second seal plate 43, and the required amount of seal air is increased. The factors include the presence of a gap provided in advance to enable assembly of the stationary blade segment and the processing accuracy of the end face of the second seal plate. In addition, during operation, the first seal plate is inclined due to the thermal expansion deviation of the adjacent stationary blade segments, and the gap may be widened.

  FIG. 1 shows a first stage stationary blade outer peripheral side sealing device that is Embodiment 1 of the present invention.

  A first seal plate 41 is provided in a first seal groove 31 extending in a straight line in the turbine axial direction in parallel with the opposing surface of the outer diameter side end wall 21 of the first stage stationary blades 11 adjacent to each other. . Further, a second seal plate 43 is provided in a second seal groove 33 that branches off from the first seal groove 31 on the opposite surface and extends linearly in the turbine radial direction in the outer diameter side hook 23. In the sealing device of the present embodiment, a deformable member 50 is fixed to an end portion of the second seal plate 43 on the high pressure side and the first seal plate 41 side.

  As an effect | action of the sealing apparatus of a present Example, first, the space | interval of the 1st seal plate 41 and the 2nd seal plate 43 is shrunk | reduced by decompression | restoration of the deformable member 50 at the time of turbine operation. This action improves the sealing performance of the butting portion regardless of the assembly gap of the seal plate, the processing accuracy of the end face of the second seal plate, and the inclination of the first seal plate due to the thermal expansion deviation of the adjacent stationary blade segment. Further, since the deformable member 50 is provided at the end portion of the second seal plate 42 on the first seal plate 41 side, the shape restoring force 61 of the deformable member 50 causes the first seal plate 41 to move to the high pressure side. By the action of pressing from the low pressure side to the low pressure side, the seal surface pressure between the first seal plate 41 and the first seal groove 31 increases, and the seal performance of the first seal plate 41 is further improved. Further, the pressing action can suppress vibrations of the first seal plate 41 and the second seal plate, and can suppress wear of the seal plate. Further, since the deformable member 50 is installed on the high pressure side of the second seal plate 43, a part of the pressure applied to the deformable member 50 from the high pressure side to the low pressure side can be supported by the second seal plate. Therefore, the damage due to the pressure difference to the second seal plate can be reduced, and the life of the member can be extended.

  As a detailed configuration example of the deformable member 50 for obtaining such an effect, there are configurations shown in FIGS. 8 to 10 described below. 8 to 10 are detailed explanatory views of specific examples of the deformable member 50 of the sealing device according to the first embodiment of the present invention. In the example shown in FIG. 8, the deformable member 50 is a thin metal plate laminate 51 in which a plurality of thin metal plates are laminated. The thin metal plate laminate 51 is fixed to the end of the second seal plate 43 by means such as welding or welding and inserted into the seal groove 33. When in contact with the first seal plate 41, deformation is possible because the rigidity is weak in the direction in which the load is applied. The length, thickness, and number of the thin plates can be adjusted according to the pressure condition and the shape of the butt portion so that the sealing performance is exhibited and the deformation is within the elastic region.

  In the example shown in FIG. 9, the deformable member 50 is a metal wire assembly in which a plurality of metal wires are bundled. The metal wire assembly 52 is fixed to the end of the second seal plate 43 by means such as welding and welding and inserted into the seal groove 33. When in contact with the first seal plate 41, deformation is possible because the rigidity is weak in the direction in which the load is applied. The alignment and thickness / density of the metal wire can be adjusted so as to exhibit sealing performance and to be deformed within the elastic region in accordance with the pressure condition and the shape of the butt portion.

  In the example shown in FIG. 10, the deformable member 50 is a heat-deformable material 53 such as a shape memory alloy or bimetal whose shape is deformed by temperature. The characteristics of the heat-deformable material 53 change at an extremely high temperature such as welding and welding. FIG. 11 shows a detailed view of the seal plate butting portion when the heat-deformable material 53 is employed as the deformable member 50 of the seal device that is Embodiment 1 of the present invention. As shown in FIG. 11, the shape of the heat-deformable material 53 is the shape of 53a in the figure that does not contact the first seal plate during assembly, and is deformed by being heated by the mainstream gas during operation of the gas turbine. It is set in advance so as to be in contact with the seal plate and to have a shape like 53b in the figure. By doing so, the seal plate can be more easily inserted during assembly, the assembly work efficiency can be improved, and the sealing performance can be exhibited during operation of the gas turbine.

  Next, another embodiment of the present invention will be described.

  FIG. 12 shows a first stage stationary blade outer peripheral side sealing device that is Embodiment 2 of the present invention.

  A first seal plate 41 is provided in a first seal groove 31 that extends in a straight line generally in the turbine axis direction, parallel to the opposing surface, on the outer diameter side end wall 21 of the first stage stationary blades 11 adjacent to each other. Further, a second seal plate 43 is provided in a second seal groove 33 that branches from the first seal groove 31 on the opposite surface and extends linearly in the turbine radial direction in the outer diameter side hook 23. According to the present embodiment, the deformable member 50 is fixed to the side wall portion of the first seal plate 41 on the high pressure side and the second seal plate 43 side.

  The operation of the seal device of this embodiment is as follows. First, the deformable member 50 reduces the gap between the first seal plate 41 and the second seal plate 43 by restoring the shape when the turbine is operating. The sealing performance of the butt portion is improved regardless of the processing accuracy of the end face of the second seal plate and the inclination of the first seal plate due to the thermal elongation deviation of the adjacent stationary blade segment. Further, the deformable force 62 of the deformable member 50 is generated, and the second seal plate 43 is pressed from the high pressure side to the low pressure side, so that the gap between the second seal plate 43 and the second seal groove 33 is increased. The sealing surface pressure is increased and the sealing performance of the second seal plate 43 is further improved.

  Although the detailed description is omitted, the same kind of effect can be obtained by applying the various examples described in the first embodiment as the deformable material of the present embodiment.

  As described above, in the embodiment of the present invention, the example in which the present invention is applied to the outer diameter side of the first stage stationary blade of the gas turbine has been described. However, the inner diameter side of the first stage stationary blade, The present invention is also applicable to locations where a plurality of constituent members such as a moving blade shroud and a stationary blade diaphragm are adjacent to each other with a gap and cooling air can leak from the gap between the constituent members. In addition to the high-temperature portion of the gas turbine, a structure having a connecting portion that connects a plurality of members to cut off the high-pressure portion and the low-pressure portion and suppresses fluid leakage from the high-pressure portion to the low-pressure portion. The invention can be applied. Here, in two regions having a difference in pressure, a region having a higher pressure than one region is referred to as a high pressure portion, and the other is referred to as a low pressure portion.

  The apparatus of the present invention can be applied to various media such as steam and nitrogen regardless of whether the high-pressure fluid and the low-pressure fluid are air, and the same effect can be obtained.

1 shows a first stage stationary blade outer peripheral side sealing device that is Embodiment 1 of the present invention. 1 shows a block diagram of a gas turbine. Sectional drawing showing the internal structure of a turbine high pressure part vicinity is shown. The AA cross section of FIG. 3 is seen from the upstream direction of mainstream gas, The annularly adjacent 1st stage stationary blade segment is shown. The figure which looked at the 1st stage stationary blade segment 11a, 11b, 11c from the turbine radial direction outer side is shown. Sectional drawing of a 1st stage stationary blade segment adjacent surface is shown. FIG. 7 is a detailed view of a seal plate butting portion in which a portion B of FIG. Detailed explanatory drawing of the specific example of the deformable member 50 of the sealing device which is Example 1 of this invention is shown. Detailed explanatory drawing of the specific example of the deformable member 50 of the sealing device which is Example 1 of this invention is shown. Detailed explanatory drawing of the specific example of the deformable member 50 of the sealing device which is Example 1 of this invention is shown. FIG. 3 shows a detailed view of a seal plate butting portion when a heat-deformable material 53 is employed as the deformable member 50 of the seal device that is Embodiment 1 of the present invention. The 1st stage stationary blade outer peripheral side sealing apparatus which is Example 2 of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Compressor 3 Combustor 4 Turbine 5 Generator 6 Main flow gas 7 Cooling air 7a First stage stationary blade cooling air 7b Second stage stationary blade cooling air 8 Casing 9 Retainer ring 10 Transition pieces 11, 13 Stator blades 12, 14 Rotor blades 15 and 16 Shroud 17 Support ring 18 Turbine wheel 19 Diaphragms 21 and 22 End walls 23 and 24 Hooks 31, 32, 33, 34 Seal grooves 41, 42, 43, 44 Seal plate 45 Holding plate 50 Member 51 Metal thin plate lamination Body 52 Metal wire assembly 53 Thermal deformation material 61, 62, 63, 64 Shape restoring force

Claims (10)

On each opposing surface of the connecting part of the connected members,
A first seal groove extending linearly;
A second seal groove branched from the first seal groove and extending linearly;
A first seal plate mounted in the first seal groove;
A second seal plate mounted in the second seal groove,
In a sealing device that connects a plurality of members to shield the high-pressure part and the low-pressure part,
A member deformable so as to reduce a gap between the first seal plate and the second seal plate is provided at a butt portion between the first seal plate and the second seal plate. Sealing device. A compressor that generates compressed air; a combustor that combusts the compressor from the compressor together with fuel; and a turbine that obtains shaft power by combustion gas from the combustor, and a plurality of stationary turbines constituting the turbine In a gas turbine having a seal device in which a seal plate is spanned over seal grooves provided on opposing surfaces between members,
The sealing device includes: a first seal groove that extends linearly; a second seal groove that branches off from the first seal groove and extends linearly; and a first seal groove mounted on the first seal groove. A seal plate, and a second seal plate mounted in the second seal groove, and the first seal plate and the second seal plate at a butting portion of the first seal plate and the second seal plate A gas turbine comprising a member that can be deformed so as to reduce a gap between the second seal plate and the second seal plate. A compressor that generates compressed air; a combustor that combusts the compressor from the compressor together with fuel; and a turbine that obtains shaft power by combustion gas from the combustor, and a plurality of stationary turbines constituting the turbine In a gas turbine having a seal device in which a seal plate is spanned over seal grooves provided on opposing surfaces between members,
The seal device includes: a first seal groove that extends linearly in the axial direction of the turbine; a second seal groove that branches from the first seal groove and extends linearly toward the outer diameter side of the turbine; A first seal plate mounted in the first seal groove; and a second seal plate mounted in the second seal groove, the first seal plate and the second seal plate. A gas turbine characterized in that a deformable member is provided at the abutting portion with the first seal plate and the second seal plate to reduce a gap between the first seal plate and the second seal plate. The sealing device according to claim 1,
The seal device, wherein the deformable member is provided at an end of the second seal plate on the first seal plate side. The sealing device according to claim 1,
The seal device, wherein the deformable member is provided on the second seal plate side of the first seal plate. The sealing device according to claim 4 or 5,
The sealing device, wherein the deformable member is provided on a high pressure side of the first seal plate or the second seal plate. The sealing device according to claim 1,
The deformable member is a sealing device in which a plurality of thin metal plates are laminated. The sealing device according to claim 1,
The deformable member is an assembly of a plurality of metal wires. The sealing device according to claim 1,
The sealing device, wherein the deformable member is a heat-deformable material. A first seal groove extending linearly, a second seal groove extending linearly branching from the first seal groove, and a first seal groove extending linearly on each facing surface of the connecting portions of the plurality of connected members, A sealing method for shielding a high-pressure part and a low-pressure part by connecting a plurality of members having a first seal plate attached to one seal groove and a second seal plate attached to the second seal groove In
A member deformable to reduce a gap between the first seal plate and the second seal plate is provided at a butt portion between the first seal plate and the second seal plate. Sealing method.

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