JPH07102997A - Ceramic gas turbine engine - Google Patents

Abstract

(57) [Summary] [Purpose] In a ceramic gas turbine engine,
Even if a thermal expansion error occurs, the ceramic insulator should not shift and contact the turbine shaft. A ceramic gas turbine engine in which a ceramic partition wall insulator 6 of a compressor turbine CT is fixed to a metal partition wall plate 3 of a compressor C, and a turbine shaft 8 penetrates the central portions of the metal partition wall plate 3 and the partition wall insulator 6, Partition insulator 6
Bosses 21 are provided radially with respect to the turbine shaft 8 at predetermined positions, and bosses 11 are provided at predetermined positions on the partition plate 3 on the outer peripheral side of the bosses 21 corresponding to the bosses 21.
11, 11 are connected by a metal spring 10, and the partition wall insulator 6 is biased and held toward the outer peripheral side of the partition wall plate 3 by the tensile force of the spring 10. As a result, even if a thermal expansion error occurs, the ceramic partition wall insulator 6 is displaced and is less likely to contact the turbine shaft 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic gas turbine engine, and more particularly, to a ceramic gas turbine engine in which a part of a turbine housing is made of ceramics to improve the difference in coefficient of thermal expansion. The present invention relates to a ceramic gas turbine engine that prevents damage to ceramics due to

[0002]

2. Description of the Related Art In recent years, gas turbine engines, for example,
In a two-shaft gas turbine engine in which a compressor and a compressor turbine are directly connected by a rotating shaft and a power turbine is separately provided, in order to improve the heat resistance of the turbine housing and improve the thermal efficiency, a gas such as a turbine housing or a turbine impeller is used. BACKGROUND ART A part of a turbine engine is formed of a ceramic material (hereinafter referred to as ceramics).

However, since the coefficient of thermal expansion differs between metal and ceramics, unless the structure of the connecting portion between them is devised, the ceramic member and the metal member can be accurately positioned due to the difference in coefficient of thermal expansion. There is a problem that it will not be broken or the ceramic will be damaged. Generally, for fixing the parts concentrically or in the rotating direction, a fixing method using a spigot and a knock pin, or a fixing method using a combination of unevenness is used. However, in fixing between ceramics and metal, since the expansion of the metal is larger than that of the ceramic due to the difference in the coefficient of linear thermal expansion, there arises a problem that the concentricity is lost or the ceramic is damaged.

Therefore, a circular recess is formed in a metal housing, and a ceramic insulator having the circular projection is combined with this, and a turbine back plate made of ceramics is fixed to the outer circumference of the ceramic insulator. Then, a configuration in which a turbine shaft is provided at the center of a metal housing, a ceramic insulator, and a ceramic back plate has been proposed (see Japanese Utility Model Laid-Open No. 3-112529). In particular,
In this proposed device, as a means for positioning the ceramic scroll of the ceramic gas turbine engine in the circumferential direction, a metal fitting is fixed to the metal structure, and a tapered groove is formed on the outer circumference of the ceramic scroll, and the metal fitting is formed in the groove. It is disclosed that they are fixed by fitting.

[0005]

However, in the ceramic gas turbine engine disclosed in Japanese Utility Model Laid-Open No. 3-112529, the ceramic insulator has a larger thermal expansion than the ceramic insulator. There was a risk of slippage and contact with the turbine shaft.

That is, in the ceramic gas turbine engine disclosed in Japanese Utility Model Laid-Open No. 3-112529, the inner periphery of the metal structure and the outer periphery of the ceramic insulator are spigot-fitted, and the insulator is used as a reference. As the other ceramic parts are concentric by spigot fitting, a gap is created between the outer peripheral part of the metal structure and the inner peripheral part of the ceramic insulator due to the difference in the coefficient of linear thermal expansion. The center position of the structure is misaligned. Since the turbine rotor (impeller) is supported by the metal structure, the gap between the tip of the rotor blade and the ceramic shroud becomes narrow, and there is a risk that the rotor may be damaged by contact with the rotor. Further, if the gap between the rotor blade tip and the ceramic shroud is increased to prevent this contact, gas flows through the gap and the performance of the gas turbine engine deteriorates.

Therefore, according to the present invention, when a ceramic turbine housing is fixed to a metal gas turbine engine housing, even if a thermal expansion error occurs, the ceramic insulator shifts and contacts the turbine shaft. It is an object to provide a fear-free ceramic gas turbine engine. Further, according to the present invention, the circular tubular exhaust duct on the downstream side of the turbine is made of ceramics, and even when the exhaust duct is connected to the metal housing, the ceramic exhaust duct is damaged by the thermal expansion of the metal housing. Another object is to provide a fear-free ceramic gas turbine engine.

[0008]

A ceramic gas turbine engine of the present invention which achieves the above object is a ceramic gas turbine engine in which a part of a turbine housing is made of ceramics, and a compressor turbine is mounted on a metal partition plate of a compressor. Ceramic partition wall insulators are provided adjacent to each other, the turbine shaft penetrates through the central portion of the partition wall plate and the partition wall insulator, at a predetermined location of the partition wall insulator, radially provided with respect to the turbine shaft. The first mounting base and a second mounting base provided at a predetermined position of the partition plate on the outer peripheral side of the first mounting base are connected by an elastic body, and the tensile force of the elastic body is used. The partition wall insulator is biased and held to the outer peripheral side of the partition wall plate. To.

Further, in the ceramic gas turbine engine of the present invention which achieves the above-mentioned other object, a ceramic circular exhaust duct downstream of the compressor turbine is connected to a metal housing via a ceramic ring. In the gas turbine engine, the ceramic ring is divided in the circumferential direction, a projection is provided on each of the divided members, and a recess fitted into the projection is provided in the metal housing.

[0010]

According to the ceramic gas turbine engine of the present invention, the partition wall insulator is provided with the first mounting base portion which is radial with respect to the turbine shaft, and the partition wall plate is located at the predetermined location on the outer peripheral side of the first mounting base portion. Even if a thermal expansion error occurs, a ceramic base made of ceramics is provided by providing a second mounting base portion on the partition wall and connecting them with an elastic body, and urging and holding the partition wall insulator toward the outer peripheral side of the partition plate by the tensile force of the elastic body. The partition wall insulator is displaced and it is difficult to contact the turbine shaft.

Further, the ceramic circular tubular exhaust duct on the downstream side of the turbine is connected to the metal housing through the circumferentially divided ceramic ring, and a projection is provided on each divided member. By providing the metal housing with the fitting recess, the ceramic ring divided in the circumferential direction moves following the projection even if the metal housing thermally expands, so the ceramic exhaust duct is less likely to be damaged. Become.

[0012]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view of a main part of a gas turbine engine showing a configuration of an embodiment of a ceramic gas turbine engine of the present invention. In this figure, a compressor C and a compressor of a gas turbine engine directly connected by a rotary shaft 8 are shown. The portion of the turbine CT is shown.

In the compressor C, a metal compressor duct 2 is incorporated in a metal plate housing 1, and a metal diffuser 3 serving as a partition wall of the compressor C is fixed to these by bolts 4 and 5, and the compressor housing 1 A compressor impeller 9 is attached to a rotary shaft 8 in a space surrounded by the compressor duct 2 and the diffuser 3.

On the other hand, in the compressor turbine CT, a scroll 14 is attached to a ceramic plate insulator 6 serving as a partition wall.
The shroud duct 17 is fitted in the inner peripheral portion of the plate 4, and the turbine impeller 7 made of ceramic is inserted in the rotating shaft 8 in the space surrounded by the plate insulator 6, the scroll 14, and the shroud duct 17. The plate insulator 6 has a plate nozzle 1
2 is fitted therein, a plurality of pin holes 13 are formed on the outer periphery of the plate insulator 6, and the scroll 14
A pin hole 15 of the same size is also formed at the relative position of. The plate insulator 6 and the scroll 14 are positioned by the pin 16.
6 also serves as a rotation stopper for the scroll 14. Also,
Shroud duct 1 fitted to the inner circumference of the scroll 14.
7 is a structure for pressing and holding the ceramic assembly composed of the plate insulator 6, the scroll 14 and the like from the exhaust side by elastic force.

Further, the rotor assembly in which the turbine impeller 7 and the compressor impeller 9 are attached to the rotary shaft 8 is cantilevered by a bearing (not shown). A metal housing 18 is fitted into the plate housing 1 of the compressor C and fastened with bolts 19. A ceramic combustor 20 is attached to the scroll 14.

In the assembly of the compressor C configured as described above, the inner circumference of the metal diffuser 3 is fitted as an inlay to the outer circumference of the plate insulator 6 with respect to the assembly of the compressor turbine CT. At this time, in this embodiment, a plurality of convex boss portions 11 are provided at predetermined intervals in the circumferential direction on the outer peripheral side of the diffuser 3 of the compressor C. Corresponding to this, the plate insulator of the compressor turbine CT is provided. Also on the outer peripheral side of 6, a plurality of convex boss portions 21 are provided at predetermined intervals in the circumferential direction. The boss portion 21 provided on the plate insulator 6 is provided on the circumference having a smaller radius than the boss portion 11 provided on the diffuser 3.

A metal S-shaped spring 1 is provided between the boss portion 21 provided on the plate insulator 6 and the boss portion 11 provided on the diffuser 3.
The plate insulator 6 is evenly pulled in the outer diameter direction of the diffuser 3 by a plurality of springs 10. FIG. 2 (a) is AA of FIG.
FIG. 3 is a local cross-sectional view taken along the line, showing the arrangement of the boss portion 11 provided on the diffuser 3 and the arrangement of the boss portion 21 provided on the plate insulator 6, and a metal member that is stretched between the boss portion 11 and the boss portion 21. 2 shows the S-shaped spring 10. In this embodiment, the boss portion 1
1 and the boss portion 21 are radially provided with respect to the rotary shaft 8 at intervals of 120, and the plate insulator 6 has three
The springs 10 are evenly pulled in the outer diameter direction of the diffuser 3. 2B is an assembly perspective view illustrating the shape of the spring 10 and the connection between the boss portion 11 and the boss portion 21 of FIG. 2A. From the viewpoint of stress concentration, the diameter of the ceramic boss portion 21 is preferably larger than the diameter of the boss portion 11.

Further, in this embodiment, in order to cool the spring 10, the metal boss portion 11 is provided with the cooling air blowout hole 22 through which the air from the compressor 1 is blown out. The cooling air blowout hole 22 communicates with the inside of the diffuser 3 of the compressor C, and the air compressed by the compressor propeller 9 serves as the cooling air.
It blows out to the spring 10 side through 2 and spring 1
0 is cooled by this cooling air. This is to prevent the spring 10 from sagging due to heat, and the cooling air of about 100 ° C. is blown from the ejection holes 22 to cool the spring 10. In addition, spring 1
If 0 can be made of ceramics, it is not necessary to install this cooling air jet hole 22.

As described above, by blowing out the cooling air from the compressor 1 through the cooling air jet holes 22 provided in the boss portion 11, the difference in thermal expansion is absorbed even at high temperature, and also against twisting. The S-shape of the spring 10 is absorbed, and the plate insulator 6 is evenly pulled in the outer diameter direction of the diffuser 3 by the three springs 10, so that its concentricity is maintained.

In the ceramic gas turbine engine constructed as described above, the air from the outside is compressed by the compressor impeller 9 and flows into the heat exchanger (not shown) through the diffuser 3 to become high temperature air, and then to the housing 18. It enters the provided combustor 20, passes through the scroll 14 as a high-temperature combustion gas, passes through the nozzle 12, rotates the turbine impeller 7, passes through the duct 17, and exhausts through a heat exchanger (not shown). To be done.

FIG. 3 (a) is an assembled sectional view showing another embodiment of the structure of the metal boss portion 11 of FIG. 2, and FIG. 3 (b) is a structure of the ceramic boss portion 21 of FIG. FIG. 7 is an assembled sectional view showing another embodiment of the present invention. In the embodiment shown in FIG. 2, the boss portion 11 is formed integrally with the diffuser 3, and the boss portion 2
1 is integrally formed with the plate insulator 6, but in the embodiment shown in FIG. 3 (a), the boss portion 11 is formed as a separate metal screw, and the screw hole 3a provided in the diffuser 3 is formed. It is designed to be screwed in and attached. Further, the boss portion 11 of this embodiment is provided with a flange 11a for preventing the spring 10 from coming off. Similarly, in the embodiment shown in FIG. 3 (b), the boss portion 21 is configured as a separate pin made of ceramics, and is attached by being bonded or welded to the mounting hole 6a provided in the plate insulator 6. ing. The boss portion 21 of this embodiment is also provided with a flange 21a for preventing the spring 10 from coming off.

In the ceramic gas turbine engine constructed as described above, the number of parts at the joint between the ceramic member and the metal member is small, the structure is simple, and the scroll 14 by the rotation of the turbine impeller 7 is used. Since the S-shape of the spring 10 is hung in the rotation direction of 1, the rotation of the scroll 14 can be prevented. Further, since the configuration including the boss portions 11 and 21 and the spring 10 can be set in a narrow space, the total length of the gas turbine engine can be shortened. Furthermore, the number of springs 10 can be increased according to the load applied to the scroll 14, the tensile load can be easily changed, and
It is also possible to reduce the load applied to the two springs 10. Furthermore, since the air from the compressor C can be blown out from the boss portion 11 to cool the spring 10, a metal spring can be used.

FIG. 4 is a longitudinal sectional view of a main part of a gas turbine engine showing the structure of another embodiment of the ceramic gas turbine engine of the present invention. In the ceramic gas turbine engine of this embodiment, a shroud duct (exhaust duct) 17 on the downstream side of the compressor turbine CT has a circular cylindrical shape made of ceramics, and is connected to a metal housing 18 via a ceramics ring. It is an example of.

In the ceramic gas turbine engine of the embodiment described with reference to FIG. 1, the metal diffuser 3 and the ceramic plate insulator 6 are provided with boss portions 11 and 21, respectively, which are connected by a spring 10. However, in the ceramic gas turbine engine of this embodiment, the metal plate housing of the compressor C is provided with the boss portion 11.
Is connected by a spring 10 to a boss portion 21 provided on the plate insulator 3 of the compressor turbine CT. Therefore, the same components as those of the ceramic gas turbine engine described in FIG. 1 are designated by the same reference numerals to simplify the description.

In FIG. 4, 1 is a plate housing made of metal, 2 is a compressor duct made of metal, 3 is a diffuser made of metal, 5 is a bolt, 6 is a plate insulator made of ceramics, 7 is a turbine impeller, and 8 is a rotation. Shaft, 9 is a compressor impeller, 10 is a metal S-shaped spring, 11 is a boss provided on the plate housing 1, 12 is a plate nozzle, 14 is a ceramic scroll, and 17 is a ceramic shroud duct ( Exhaust duct), 18 is a metal housing, 2
Reference numeral 0 is a ceramic combustor, 21 is a boss portion provided in the plate insulator 6, 22 is a cooling air ejection hole provided in the boss portion 23, 23 is an ignition plug, 24 is a fuel injection nozzle, and 27 is a power turbine. The power rotor is shown. Further, in this embodiment, a ceramic housing 14a is provided between the scroll 14 and the exhaust duct 17, and the exhaust duct 17 is formed by the housing 1a.
4a and the flange portion 18a of the metal housing are connected.

The air compressed by the compressor C passes through the diffuser 3, the scroll, and the heat exchanger (not shown) into the combustor 20. The inflowing high-temperature air is mixed with fuel in the combustor 20 and burned to form combustion gas, which rotates the impeller 7 through the scroll 14 and the compressor turbine CT and flows through the exhaust duct 17 to rotate the power rotor 27. It passes through a heat exchanger (not shown) and is discharged to the atmosphere.

FIG. 5 shows the compressor turbine CT of FIG.
Only the exhaust duct 17 on the downstream side of is taken out, and the connection between the exhaust duct 17, the ceramic housing 14a, and the flange portion 18a of the metal housing is shown. The exhaust duct 17 has a tubular shape in which the diameter on the exhaust downstream side is larger than the diameter on the upstream side.
a flange portion 17a connected to a is provided on the exhaust downstream side,
A hakama portion 17b connected to the ceramic housing 14a is provided on the upstream side of the exhaust gas.

A coil spring 30 made of ceramics is inserted in a connecting portion between the hakama portion 17b of the exhaust duct 17 and the housing 14a, and the exhaust duct 17 is urged by the coil spring 30 toward the exhaust downstream side.
On the other hand, a ceramic ring 25 and a gasket 26 are inserted between the flange portion 17a of the exhaust duct 17 and the flange portion 18a of the metal housing. The gasket 26 is inserted to absorb the strain of the metal flange portion 18a and to seal the exhaust gas in the exhaust duct 17 so as not to leak to the combustor 20 side.

FIG. 6 shows the ceramic ring 25 of FIG.
The details of the shape of the gasket 26 and the flange portion 18a of the metal housing 18 are shown. The ceramic ring 25 is evenly divided in the circumferential direction, and each of the divided members 25a has a spherical projection 25b at the center thereof.
Is provided. On the other hand, the protrusion 26 is provided on the gasket 26 that is superposed on the ceramic ring 25.
A protrusion insertion hole 26a is provided at a position corresponding to 5b. The height of the protrusion 25b is larger than the depth of the protrusion insertion hole 26a, and when the protrusion 25b is inserted through the protrusion insertion hole 26a, the spherical tip end of the protrusion 25b has a spherical shape.
6 is projected from the surface.

Further, the flange portion 18a of the metal housing 18 is provided with a groove 28 for receiving the gasket 26, and the groove 28 has a ball hole 29 corresponding to the projection insertion hole 26a provided in the gasket 26. That is, a spherical hole 29 for receiving the spherical tip portion of the protrusion 25b protruding from the surface of the gasket 26 is provided. As described above, in this embodiment, the gasket 26 is provided in the groove 28 provided in the flange portion 18a of the metal housing 18 and the groove 28 is formed.
Align the projection insertion hole 26a with the spherical hole 29 of
The ring 25 is attached to the gasket 26 by fitting the projections 25b on the divided ceramic ring 25, and the exhaust duct 17 is superposed on the back side of the ring 25 without the projection 25b. The exhaust duct 17 is a ceramic coil. By connecting to the ceramic housing 14a on the compressor turbine CT side using the spring 30, the following effects can be expected.

(1) The heat transfer to the flange portion 18a is reduced and the heat distortion is reduced. (2) Due to the sealing property of the gasket 26, leakage of exhaust gas is reduced. (3) Since the ceramic ring 25 is divided, the ring 25 is prevented from being broken by thermal stress. (4) By fitting the projection 25b provided on the ceramic ring 25 and the spherical hole 29 provided on the flange portion 18a,
The ring 25 freely moves against the thermal strain (radial direction, circumferential direction, twisting direction, etc.) of the metal flange portion 18a,
Since the contact surfaces of the flange portion 17a of the exhaust duct 17 are held in parallel, the exhaust gas leakage is reduced.

(5) The protrusion 25b of the ring 25 and the spherical hole 29 of the flange portion 18a are fitted in the concavo-convex shape so that the distance between the flanges is maintained and exhaust gas leakage is reduced.

[0033]

As described above, according to the ceramic gas turbine engine of the present invention, the partition wall insulator is provided with the first mounting base portion that is radial with respect to the turbine shaft at a predetermined location of the partition wall insulator. A second expansion base portion is provided at a predetermined position of the partition plate on the outer peripheral side, both are connected by an elastic body, and the partition wall insulator is biased and held by the elastic body to the outer peripheral side of the partition plate, so that the thermal expansion error is reduced. Even if it occurs, there is an effect that the ceramic partition wall insulator is displaced and becomes difficult to contact the turbine shaft. .

Further, the ceramic circular tubular exhaust duct on the downstream side of the turbine is connected to the metal housing via the ceramic ring divided in the circumferential direction, and
By providing a protrusion on each of the divided members and providing a concave portion to be fitted to the protrusion on the metal housing, the ceramic ring divided in the circumferential direction follows the convex portion even if the metal housing thermally expands. Since it moves, the ceramic exhaust duct is less likely to be damaged.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part of a gas turbine engine showing a configuration of an embodiment of a ceramic gas turbine engine of the present invention.

2A is a local cross-sectional view taken along the line AA in FIG. 1, and FIG. 2B is an assembled perspective view illustrating the shape and connection of the elastic body in FIG.

3 (a) is an assembled sectional view showing another embodiment of the structure of the boss on the metal partition plate side of FIG. 2, and FIG. 3 (b) is a sectional view of the boss structure on the ceramic partition wall side of FIG. It is an assembly sectional view showing another example.

FIG. 4 is a longitudinal sectional view of a main part of a gas turbine engine showing the configuration of another embodiment of the ceramic gas turbine engine of the present invention.

5 is a longitudinal cross-sectional view of essential parts showing the connection between a ceramic circular exhaust duct on the downstream side of the compressor turbine in FIG. 4 and a metal housing.

FIG. 6 is a ceramic ring in the case where the circular ceramic exhaust duct shown in FIG. 5 and a metal housing are connected via a ceramic ring divided in the circumferential direction;
It is an assembly perspective view with a gasket and a metal housing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Metal plate housing 2 ... Metal compressor duct 3 ... Metal diffuser 4, 5 ... Bolt 6 ... Plate insulator 7 ... Turbine impeller 8 ... Rotating shaft 9 ... Compressor impeller 10 ... Spring 11 ... Boss part 12 ... Plate nozzle 13 ... Pin hole 14 ... Scroll 15 ... Pin hole 16 ... Pin 17 ... Shroud duct 17a ... Flange part 17b ... Hakama part 18 ... Metal housing 18a ... Flange part 19 ... Bolt 20 ... Ceramic combustor 21 ... Boss part 22 ... Cooling air jetting hole 25 ... Ceramic ring 25a ... Dividing member 25b ... Projection 26 ... Gasket 26a ... Projection insertion hole 27 ... Power rotor 28 ... Groove 29 ... Spherical hole 30 ... Ceramic spring

Claims (2)

[Claims] 1. A ceramic gas turbine engine in which a part of a turbine housing is made of ceramics, wherein a ceramic partition wall insulator of a compressor turbine is provided adjacent to a metal partition wall plate of a compressor, and the partition wall plate and the partition wall. In a turbine shaft penetrating a central portion of an insulator, a first mounting base portion radially provided with respect to the turbine shaft at a predetermined location of the partition wall insulator, and a first mounting base portion corresponding to the first mounting base portion A second mounting base portion provided at a predetermined position on the outer peripheral side of the partition plate is connected by an elastic body, and the partition wall insulator is biased and held by the elastic body to the outer peripheral side of the partition plate. A ceramic gas turbine engine. 2. The ceramic gas turbine engine according to claim 1, wherein a circular ceramic exhaust duct located downstream of the compressor turbine is connected to a metal housing via a ceramic ring. While dividing in the circumferential direction,
A protrusion is provided on each of the divided members, and a recess fitted into the protrusion is provided on the metal housing.