JPH01244121A - Combustor for ceramics gas turbine - Google Patents

Abstract

PURPOSE:To prevent rupture of a combustor, by a method wherein the two end parts, in the direction of an axis, of a combustor are supported to a combustor casing through the energizing force of a spring. CONSTITUTION:A bolt 67 is loosely engaged with the holes of a flange part 33a of a transition duct 33 of a combustor 9 made of ceramics and a metallic plate 66 of a main casing 1, and a soil spring 68 is located between the head part of the bolt 67 and the flange 33a. A coil spring 70 is provided between the other end of a liner support 36 of the combustor 9 and a spring press 69 of the combustor casing 2. This constitution enables absorption of a difference in thermal expansion through the expansion and contraction of the spring to prevent rupture of the combustor.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a ceramic gas turbine in which a portion exposed to high-temperature and high-pressure gas is made of ceramic.
The present invention relates to a combustor that burns a mixture of compressed air and fuel.

(Prior Art) A conventional gas turbine is constructed by assembling metal parts, and the combustor is also made of a heat-resistant alloy.

(Problem to be solved by the invention) However, in the above conventional configuration, the temperature of 1000°C without cooling is
Operation at higher gas temperatures was impossible and the efficiency was not sufficient. Furthermore, if an air cooling structure is adopted, operation at temperatures above 1000°C is possible, but in this case, power loss occurs due to air cooling.

Therefore, it is possible to construct the parts exposed to high-temperature, high-pressure gases using ceramics with excellent heat resistance, but ceramics with excellent heat resistance are hard and easily cracked, so if a restraining force is applied during thermal expansion, easily damaged. In particular, the combustor is the part that reaches the highest temperature and is large, so if the whole is molded as one piece of ceramic, it will easily break due to thermal expansion, and if it is divided into multiple pieces, the pieces should be connected with bolts. If they are tightly connected using nuts, etc., they will easily break due to the difference in thermal expansion. Furthermore, since ceramics and metals have different coefficients of thermal expansion, if a ceramic combustor is firmly supported by a metal combustor casing, an excessive force will be applied to the combustor during thermal expansion, causing the ceramic parts to break.

(Means for Solving the Problems) In order to solve the above problems, a combustor for a ceramic gas turbine according to the present invention includes a combustor that combusts a mixture of compressed air and fuel compressed by a compressor, and a combustor that combusts a mixture of compressed air and fuel compressed by a compressor. A gas generator turbine section that is supplied with high-temperature, high-pressure gas from a container to drive the compressor, and a power turbine section that communicates with the gas generator turbine section and rotationally drives a power turbine rotor are each made of ceramics. In a ceramic gas turbine, both ends of the combustor in the axial direction are supported by the combustor casing by the biasing force of a spring, and the combustor is divided into a plurality of pieces at appropriate positions in the axial direction, and each divided piece is placed in contact with another. The contact surface is shaped to form part of a spherical surface.

(Function) When the combustor is exposed to high-temperature, high-pressure gas and thermally expands, the combustor is supported by the combustor casing by the biasing force of the spring, so the difference between the ceramic combustor and the metal combustor casing increases. The difference in thermal expansion is absorbed by the expansion and contraction of the spring. Also, since the combustor is divided into multiple pieces,
Unlike when the whole is molded as one piece, large internal stress does not act upon thermal expansion and cause breakage, and each divided piece comes into contact with the contact surface that forms part of a spherical surface. Therefore, no restraining force acts between the divided pieces during thermal expansion, and at the same time, even if there are some manufacturing errors in each divided piece, the contact surfaces of the divided pieces come into smooth contact with each other.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 1 to 7.

° Fig. 1 is a partially cutaway plan view of a ceramic gas turbine according to an embodiment of the present invention, and Fig. 2 is a longitudinal sectional front view of the same main part. 2 (FIG. 2) is attached with a plurality of bolts 3. A compressor 5, a gas generator turbine section 6, a power turbine section 7, and a heat exchanger 8 are installed inside the main casing 1, and a combustor 9 is installed inside the combustor casing 2. The air compressed by the compressor 5 is heated while passing through the heat exchanger 8 and flows into the combustor 9, where it is mixed with fuel and combusted, and the high temperature and high pressure gas generated thereby is gas. The gas is supplied to the generator turbine section 6 to drive the compressor 5, and further supplied from the gas generator turbine section 6 to the power turbine section 7 to generate output.

The gas generator turbine section 6 includes a rotor 12 having a plurality of rotor blades 11 integrally protruding from the outer periphery at appropriate intervals in the circumferential direction, and a substantially annular back plate 13 that closely opposes one end of the rotor blades 11. and a substantially annular turbine shroud 14 that closely opposes the other end of the rotor blade 11;
An annular turbine nozzle 15 is sandwiched between the back plate 13 and the turbine shroud 14 and faces closely to the outer circumference of the rotor blade 11; and a turbine nozzle whose inner circumference is sandwiched between the back plate 13 and the turbine shroud 14. A substantially annular turbine inlet duct 1 abutting the outer periphery of 15
6, a cylindrical first outer intermediate duct 17 whose one end abuts the protruding end of the inner circumference of the turbine shroud 14, which has a substantially L-shaped cross section along the radial direction; The cone-shaped inner intermediate duct 18 is loosely fitted on the inner periphery of the first outer intermediate duct 17 at a predetermined interval in the radial direction, and one end of the inner intermediate duct 18 is loosely fitted in the inner periphery of the first outer intermediate duct 17. It is molded from ceramics with excellent heat resistance such as silicon carbide. The turbine nozzle 15 has a structure in which a large number of divided pieces are arranged adjacent to each other in the circumferential direction, and each divided piece is integrally formed with one blade 15a. A wave spring 19 made of ceramic is interposed between the back plate 13 and the turbine nozzle 15, and the wave spring 19 is annular and molded into pieces in the circumferential direction. The contact portion between the protruding end of the inner peripheral portion of the turbine shroud 14 and one end of the first outer intermediate duct 17 is opposed to each other in both the axial direction and the radial direction, and there is a gap between the opposing surfaces in the radial direction. A seal ring 20 made of ceramic is interposed therein. The back plate 13
The contact surface 21 between the turbine inlet duct 16 and the turbine inlet duct 16 is inclined at an angle of 39° or more with respect to the horizontal direction.

The first outer intermediate duct 17 and the inner intermediate duct 18 are connected to each other by ceramic pins 22 that are loosely fitted into a plurality of holes formed along the radial direction at appropriate intervals in the circumferential direction. , this bottle 22 is
As shown in detail in FIGS. 3 to 5, there is a notch 23 in the head.
In addition, in order to reduce gas flow resistance, a portion located in the gap between the first outer intermediate duct 17 and the inner intermediate duct 18 constitutes a wing 24. The notch 23 has a bottom surface forming a part of a cylindrical surface, and the both ends of the notch 23 have a semicircular cross section and gradually become thinner from one end to the other end.

The power turbine section 7 has one end in contact with the other end of the first outer intermediate duct 17, and is loosely fitted in the outer periphery of the inner intermediate duct 18 at a predetermined interval in the radial direction on the other end side of the center section of the inner intermediate duct 18. The second outer intermediate duct 26 has a cylindrical shape, and has a double cylindrical shape consisting of an outer cylindrical body 27a and an inner cylindrical body 27b, and one end of the outer cylindrical body 27a is in contact with the other end of the second outer intermediate duct 26. Contacting exhaust diff user-2
7, a large number of power turbine nozzles 28 arranged at appropriate intervals in the circumferential direction between the other end of the second outer intermediate duct 26 and the other end of the inner intermediate duct 18, and the outer cylindrical body 27a. It consists of a power turbine section, which is arranged in large numbers at appropriate intervals in the circumferential direction on the inner circumferential side of one end, and some two of them, and these are made of ceramics with excellent heat resistance such as silicon nitride or silicon carbide. There is.

The plurality of power turbine nozzles 28 have an integrally formed cylindrical protrusion 28a that penetrates a hole in a power turbine shroud 26a formed by the other end of the second outer intermediate duct 26 and protrudes toward the outer circumferential side. The protruding portions are connected to each other by a metal connector 30. Therefore, by rotating the power turbine nozzle 28 at an arbitrary angle around the axis of the cylindrical protrusion 28a, the angle of the power turbine nozzle 28 with respect to the gas flow can be freely adjusted. Said second outer intermediate duct 26
A flange portion 26b integrally projects in the axial direction from the outer periphery of the other end, and a ceramic plate is disposed between the inner periphery of the flange portion 26b and the outer periphery of the outer cylindrical body 27a of the exhaust diff user 27. A seal ring 31 is interposed.

As shown in FIG. 2, the combustor 9 includes a transition duct 33, which has a substantially cylindrical shape with one end having a larger diameter than the other end, and one end of which abuts the open end of the flange portion 16a of the turbine inlet duct 16; It is composed of a cylindrical combustor liner 34 whose one end abuts against the other end of the transition duct 33, and a substantially annular first liner support 35 whose one end abuts the other end of the combustor liner 34.
These are made of ceramics with excellent heat resistance, such as silicon nitride or silicon carbide.

One end of a substantially cylindrical second liner support 36 made of ceramics is in contact with the other end of the first liner support 35, and a hole 37 is provided in the combustor liner 34.
is formed, and the tip of the spark plug 38 fixed to the combustor casing 2 is fitted therein. The contact surface between the other end of the transition duct 33 and one end of the combustor liner 34 and the contact surface between the other end of the combustor liner 34 and one end of the first liner support 35 constitute a part of a spherical surface. It is shaped like this.

One end of the rotor 12 has a hollow metal rotating shaft 42 rotatably supported at both ends by bearings 40° 41.
A large number of blades 5a of the compressor 5 are fixed to the outer periphery of the rotating shaft 42 at appropriate intervals in the circumferential direction. On the outer periphery of the back plate 13, a plurality of protrusions 13a protruding outward in the radial direction are integrally provided at appropriate intervals in the circumferential direction. It is in contact with the annular plate 43 of. Pins 44 that loosely fit into the holes of both the protrusions 13a and the annular plate 43 are provided, and a coil spring 46 is installed between the annular plate 43 and a cotter 45 implanted at the tip of each pin 44. is interposed.

As shown in FIGS. 6 and 7, the first outer intermediate duct 17 has a plurality of protrusions 17a integrally provided on the outer peripheral surface of the other end at appropriate intervals in the circumferential direction, and each protrusion 17
A hole 48 is formed along the axial direction in a. One end of the second outer intermediate duct 26 also has a similar configuration, and the outer periphery of the other end of the first outer intermediate duct 17 and one end of the second outer intermediate duct 26 is made of metal and has an annular separator. The inner periphery of the separator 49 and the outer periphery of the other end of the first outer intermediate duct 17 and one end of the second outer intermediate duct 26 are connected to an annular ceramic ring. The intermediate duct attachment is sandwiched between a ring 50 and a metal annular plate 51.

The intermediate duct is attached using a plurality of pins 52 that loosely fit into the hole of the ring 50, the hole 48 of the first outer intermediate duct 17, the hole of the second outer intermediate duct 26, and the hole of the annular plate 51.
are provided at appropriate intervals in the circumferential direction, and a coil spring 54 is interposed between the cock 53 implanted at the tip of each pin 52 and the annular plate 43. In the intermediate duct attachment, the inner circumference of the ring 50 protrudes toward one end in the axial direction and engages with the notch 23 of the pin 22, thereby preventing the pin 22 from rotating.

The inner peripheral edge of the large number of power turbine blades 29 is
They fit into a number of grooves formed along the axial direction at appropriate circumferential intervals on the outer periphery of the power turbine rotor 56, and the outer periphery of the power turbine rotor 56 and the inner periphery of the power turbine blades 29 are connected to each other. are sandwiched between a pair of metal plates 57, which are connected to each other by a rivet 58 passing through the power turbine rotor 56° in the axial direction. The power turbine rotor 56 is fixed to one end of a power turbine shaft 61 which is rotatably supported at both ends by bearings 59 and 60, and this power turbine shaft 61 is connected to an output shaft 62 via a reduction gear (not shown). is connected to.

An annular protrusion 27c is integrally provided on the inner periphery of the inner cylindrical body 27b of the exhaust diff user 27 in a state that is inclined with respect to the radial direction. It fits into an annular recess with a triangular radial cross section formed on the outer periphery of the portion 1a and the bearing holder 63, and a metal annular leaf spring 64 is provided between the protrusion 27c and the bearing holder 63. It has been intervened.

A flange portion 33a is integrally provided on the transition duct 33 of the combustor 9 at a predetermined location on the outer periphery of one end, and this flange portion 33g is mounted on a metal plate 66 attached to the main casing 1. It is placed. Bolts 6 are inserted into the holes of the flange portion 33a and the metal plate 66.
7 is loosely fitted, and the head of the bolt 67 and the flange part 33
A coil spring 68 is interposed between a and a. A coil spring 70 is interposed between the other end of the second liner support 36 and a spring retainer 69 attached to the combustor casing 2.
The liner support 36 is biased toward one end in the axial direction. The position of the bolt 67 penetrating portion of the flange portion 33a is on the extension of the axis of the second liner support 36.

A fuel injection nozzle 71 is fitted into the inner periphery of the second liner support 36, and this fuel injection nozzle 71 injects fuel such as kerosene or light oil supplied from the fuel supply lower 2 into the combustor casing 2. do.

An annular flange 74 integrally protruding from the main casing 1 is disposed on the radially outer side of the separator 49, and the outer periphery of the separator 49 and the inner periphery of the annular flange 74 both have an oval-shaped cross section. and are opposed in both the axial direction and the radial direction. A coil spring 75 is interposed between the opposing surfaces in the axial direction.

Next, the effect will be explained. The air compressed by the compressor 5 is sent to the heat exchanger 8 through the passage 78 and is heated while passing through the heat exchanger 8 and reaches the space 79 . Then, it flows into the interior of the combustor 9 through the hole 37 of the combustor liner 34 . On the other hand, the fuel supplied from the fuel supply lower 2 is injected into the combustor 9 from the fuel injection nozzle 71 and mixed with compressed air to form an air-fuel mixture. When a spark is generated from the ignition plug 38, the air-fuel mixture is combusted and high-temperature, high-pressure gas is generated. This high-temperature, high-pressure gas passes through the turbine inlet duct 16 and is injected from the turbine nozzle 15.
A component force is applied to the rotor blade 11 in the circumferential direction. As a result, the rotor 12 rotates, the rotating shaft 42 rotates together with the rotor 12, and the compressor 5 continues to operate. The high-temperature, high-pressure gas that rotated the rotor 12 fills the annular space between the first outer intermediate duct 17 and the inner intermediate duct 18 and the annular space between the second outer intermediate duct 26 and the inner intermediate duct 18. is injected from the power turbine nozzle 28 and applies a component force in the circumferential direction to the power turbine blade 29. As a result, the power turbine rotor 56 rotates, the power turbine shaft 61 rotates together with the power turbine rotor 56, and the output shaft 62 is driven via a reduction gear (not shown). power turbine rotor 5
6 is discharged from the end opening of the exhaust diffuser 27 through the space 80 and the heat exchanger 8 through the exhaust port 81.

Here, the combustor 9 and the like thermally expand due to the high-temperature and high-pressure gas, but the flange portion 33a of the transition duct 33 is connected to the metal plate 6
The combustor 9 and the combustor casing 2 are connected to each other by the urging force of the coil spring 68, and the entire combustor 9 is pressed toward the joint portion between the flange portion 33a and the metal plate 66 by the urging force of the coil spring 70. The difference in thermal expansion between the coil springs 68 and 70 is well absorbed by the expansion and contraction of the coil springs 68 and 70. Moreover, since the combustor 9 is divided into the transition duct 33, the combustor liner 34, and the first liner support 35, compared to the case where the whole is molded as one piece,
It is very easy to manufacture, and at the same time, the internal stress that acts upon thermal expansion is small. Further, the connection between the other end of the transition duct 33 and one end of the combustor liner 34 and the connection between the other end of the combustor liner 34 and one end of the first liner support 35 are simply in contact with each other. So,
Displacement is free during thermal expansion, and no binding force acts on each other. Furthermore, since these connecting portions are in contact with the abutting surfaces forming part of the spherical surfaces, even if there are some manufacturing errors, the abutting surfaces are in smooth contact and are stably held.

In this embodiment, the connection portion between the gas generator turbine section 6 and the power turbine section 7 is connected to the first outer intermediate duct 1.
The other end of the second outer intermediate duct 26 and one end of the second outer intermediate duct 26 are not connected by bolts or the like, but are simply connected by the biasing force of the coil spring 54 as a thermal expansion absorbing means. Therefore, no unreasonable force is exerted between the two due to thermal expansion. In addition, the connection part between the gas generator turbine part 6 and the combustor 9 is not connected by bolts or the like between the open end of the flange part 16a of the turbine inlet duct 16 and one end of the transition duct 33, but by absorbing thermal expansion. Since both are simply brought into contact as a means, no unreasonable force is exerted between them due to thermal expansion. Further, the supporting part of the gas generator turbine part 6 to the main casing 1 connects the back plate 13 to the annular plate 43 by the urging force of the coil spring 46, and connects the other end of the first outer intermediate duct 17 to the second outer intermediate duct 17. Since the outer intermediate duct 26 is connected to the separator 49 by the biasing force of the coil spring 54, and the coil spring 75 is interposed between the separator 49 and the annular flange 74, the gas generator turbine section 6 The difference in thermal expansion between the main casing 1 and the main casing 1 is well absorbed by the expansion and contraction of the coil springs 46, 54, and 75. Further, the support portion of the power turbine section 7 to the main casing 1 is configured such that one end of the second outer intermediate duct 26 and the other end of the first outer intermediate duct 17 are supported by the separator 49 by the biasing force of the coil spring 54.
Since the coil spring 75 is interposed between the separator 49 and the annular flange 74, the difference in thermal expansion between the power turbine section 7 and the main casing 1 is the same as that between the coil spring 54 and the coil spring 75. Good absorption due to expansion and contraction. In addition, the gas generator turbine section 6 and power turbine section 7, which are ceramic products, are further subdivided into multiple parts in the same way as the combustor 9, making manufacturing extremely easy and reducing damage caused by thermal expansion. do. In addition, since the contact surface 21 between the back plate 13 and the turbine inlet duct 16 is sloped at an angle of 39@ or more with respect to the horizontal plane, the turbine inlet duct 16 deforms slightly outward in the radial direction during thermal expansion, and the back plate 13 and It is possible to prevent the turbine inlet duct 16 from sliding relative to the turbine inlet duct 16 on the abutting surface 21, thereby preventing unreasonable force from acting between the back plate 13 and the turbine inlet duct 16. In addition, since a wave spring 19 made of ceramic is interposed between the back plate 13 and the turbine nozzle 15, this wave spring 1
9 can also absorb deformation due to thermal expansion. In addition, the gas generator turbine section 6 and the power turbine section 7 are separated by the biasing force of the coil spring 54 and the biasing force of the coil spring 75.
Since it is supported on the main casing 1 via a staged displacement allowance mechanism, deformation due to thermal expansion can be largely absorbed. In addition, since the double cylindrical intermediate duct is divided into an inner and an outer side, that is, first and second outer intermediate ducts 17.26 and an inner intermediate duct 18, the power turbine nozzle 28
can be easily inserted.

(Effects of the Invention) As explained above, according to the present invention, there is provided a combustor that combusts a mixture of compressed air and fuel compressed by a compressor, and a combustor that is supplied with high temperature and high pressure gas. In a ceramic gas turbine in which a gas generator turbine section that drives a compressor and a power turbine section that communicates with the gas generator turbine section and rotationally drives a power turbine rotor are each made of ceramic, the axial center of the combustor Both ends in the direction are supported by the combustor casing by the biasing force of a spring, and the combustor is divided into a plurality of pieces at appropriate positions in the axial direction, and the contact surface of each divided piece forms a part of a spherical surface. Since both ends of the combustor in the axial direction are supported on the combustor casing by the biasing force of the spring, the difference in thermal expansion between the ceramic combustor and the metal combustor casing is due to the expansion and contraction of the spring. Well absorbed. Moreover, since the combustor is divided into multiple pieces, it is much easier to manufacture than when the whole is molded as one piece, and at the same time, the internal stress that acts upon thermal expansion is small.
Not easy to damage. In addition, since the connecting parts between the divided pieces are simply in contact with each other, they are free to displace during thermal expansion, and there is no binding force acting on each other, which also helps prevent damage caused by thermal expansion. can be prevented. Furthermore, since these connecting parts are in contact with the abutting surfaces that form part of the spherical surface, even if there are some manufacturing errors, the abutting surfaces will make smooth contact and each divided piece will be held stably. be done.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view of a ceramic gas turbine according to an embodiment of the present invention, FIG. 2 is a vertical sectional front view of the same main part,
Fig. 3 is a front view of the pin, Fig. 4 is a side view of the same main part, Fig. 5 is a sectional view taken along the V-■ arrow in Fig. 3, Fig. 6 is a front view of the first outer intermediate duct, and Fig. 6 is a front view of the first outer intermediate duct. Figure 7 is a longitudinal sectional side view of the same.

Claims (1)

[Claims] 1. A combustor that burns a mixture of compressed air and fuel compressed by a compressor, a gas generator turbine section that is supplied with high-temperature, high-pressure gas from this combustor and drives the compressor, and this gas In a ceramic gas turbine in which a power turbine part that communicates with a generator turbine part and rotationally drives a power turbine rotor is made of ceramic, both ends of the combustor in the axial direction are supported by a combustor casing by the biasing force of a spring. A combustor for a ceramic gas turbine is further characterized in that the combustor is divided into a plurality of pieces at appropriate positions in the axial direction, and the abutment surfaces of the divided pieces are shaped to form part of a spherical surface.