JPH08312961A - Combustor for gas turbine - Google Patents

Abstract

PURPOSE: To improve the strength of a ceramic liner and to improve the productivity in the combustor for a gas turbine having the liner. CONSTITUTION: This combustor for a gas turbine has a ceramic liner 1 formed in a cylindrical shape for partitioning a combustion chamber 11 and a metal dome 2 formed in a bowl shape coupled to the base end side of the liner 1, and comprises a C-shaped seal ring 20 slidably engaged with the outer periphery 27 of the dome 2, and a plurality of leaf springs 15 for pressing the ring 20 to the base end surface 18 of the liner 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a gas turbine combustor having a ceramic liner.

[0002]

2. Description of the Related Art In a gas turbine in which a liner (combustion cylinder) used in a high temperature atmosphere is formed of a ceramic material, it is necessary to avoid stress concentration on the brittle ceramic material.

As a conventional gas turbine combustor, for example, there is one shown in FIG. 5 (Japanese Patent Laid-Open No. 56-7452).
No. 8, gazette).

To explain this, a combustor of a gas turbine has a cylindrical ceramic liner 51 that defines a combustion chamber 50, and a bowl-shaped ceramic dome 52 connected to the base end side of the liner 51. With.

As shown in FIG. 6, the front end flange portion 53 of the dome 52 is fitted to the inner peripheral surface of the liner 51, and both are fastened via a plurality of metal clamps 54.

Holes 55 and 56 are formed in the tip flange portion 53 of the dome 52 and the liner 51 by machining. The dome 52 is inserted through the pins 56 inserted into the holes 55 and 56.
The rotation of the liner 51 with respect to is locked.

During operation of the gas turbine, since the dome 52 and the liner 51 are used in a high temperature atmosphere, a difference in thermal expansion occurs between the members, and the clamps 54 are elastic to the difference in thermal expansion. It is supposed to deform.

[0008]

However, in such a conventional gas turbine combustor, the dome 5 is used.
Since stress concentrates on the holes 55 and 56 formed by machining in the second tip flange portion 53 and the liner 51, it is difficult to secure sufficient strength.

Further, machining the ceramic material causes a large increase in production cost.

Since the thickness of the ceramic dome 52 is greatly changed at the tip flange portion 53, the dome 52
It is difficult to increase productivity because cracking and deformation are likely to occur during molding and firing.

An object of the present invention is to solve the above problems and to improve the strength of the liner and the productivity of the gas turbine combustor provided with the ceramic liner.

[0012]

A combustor for a gas turbine according to claim 1 has a cylindrical ceramic liner defining a combustion chamber, and a bowl shape connected to a base end portion of the liner. In a gas turbine combustor including a metal dome, a C-shaped seal ring slidably fitted to an outer peripheral surface of the dome, and an urging means for pressing the seal ring against the base end surface of the liner. Prepare

According to a second aspect of the present invention, in the gas turbine combustor according to the first aspect, a plurality of strip-plate-shaped leaf springs are provided as the biasing means.

According to a third aspect of the present invention, in the gas turbine combustor according to the first aspect, a plurality of coiled coil springs are provided as the biasing means.

According to a fourth aspect of the present invention, in the gas turbine combustor according to the first aspect, a single coil-shaped coil spring is arranged concentrically with the dome as the biasing means.

[0016]

In the gas turbine combustor according to the first aspect of the present invention, the liner is axially pressed by the force of the biasing means via the seal ring, and the liner is elastically supported with respect to the engine casing.

The C-shaped seal ring is joined to the outer peripheral surface of the dome without a gap due to its elastic restoring force, and is pressed against the base end face of the liner by the force of the biasing means, so that a gap is formed at the joint portion between the two. And the sealing property of the combustion chamber is ensured.

During operation of the gas turbine, since the dome and the liner are used in a high temperature atmosphere, a difference in thermal expansion of the liner with respect to the dome occurs. This difference in thermal expansion causes the base end face of the ceramic liner to act as a seal ring. The outer circumference of the dome slides axially with respect to the seal ring while being slid in the radial direction. As a result, it is possible to prevent permanent deformation of the metal dome and the like, and it is also possible to prevent stress concentration on the ceramic liner and damage.

Since the ceramic liner is formed in a simple cylindrical shape, is not machined, and has no portion where the cross-sectional shape changes abruptly, stress concentration occurs during operation of the gas turbine. By preventing breakage and preventing cracks and deformation during molding and firing of the liner, productivity can be improved and product cost can be reduced.

In the combustor of the gas turbine according to the present invention, the liner is axially pressed by the elastic restoring force of the plurality of leaf springs via the seal ring, and the liner is elastically supported with respect to the engine casing. To be done.

In the combustor for a gas turbine according to a third aspect of the present invention, the liner is axially pressed through the seal ring by the elastic restoring force of the plurality of coil springs, and the liner is elastically supported with respect to the engine casing. It

In the combustor of the gas turbine according to claim 4, the liner is axially pressed by the elastic restoring force of the single coil spring via the seal ring, and the liner is elastically supported with respect to the engine casing. To be done.

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, the combustor of the gas turbine includes a cylindrical ceramic liner 1 defining a combustion chamber 11, and a bowl-shaped metal liner connected to the proximal end of the liner 1. And a dome 2.

A swirler 3 having a cylindrical shape on the base end side of the dome 2.
Is connected. The intake air pressure-fed from a compressor (not shown) passes through the heat exchanger, then is guided to the swirler 3 through the flow passages defined outside the liner 1 and the dome 2, and from each slit 7 opened in the swirler 3. Combustion chamber 11
Inflow while turning to.

A fuel injection valve 9 is arranged inside the swirler 3. The fuel injected from the fuel injection valve 9 into the combustion chamber 11 mixes with the intake air introduced from the swirler 3 to form a diffusion flame.

A base end portion (not shown) of the swirler 3 is fixedly connected to the nozzle holder 5, and the nozzle holder 5 is fixedly connected to the engine casing 6 via bolts or the like.

An ignition plug 12 is attached to the combustion chamber 11 via the nozzle holder 5.

The liner 1 is formed in a right cylinder shape, and a plurality of dilution air ports 19 are opened in the middle thereof. The tip of the liner 1 is fitted into the inlet 14 of the scroll 8. The gas burned in the combustion chamber 11 is guided to a turbine (not shown) through the scroll 8 and rotationally drives the turbine.

The inlet section 14 of the scroll 8 is bent in a crank shape in cross section to integrally form an annular step section 33 for joining the tip end surface 32 of the liner 1. The inner diameter d1 of the opening of the inlet portion 14 is formed larger than the outer diameter D1 of the liner 1. The inner diameter d2 of the scroll 8 is equal to that of the liner 1.
Is formed smaller than the inner diameter d3 of the liner 1 at a predetermined ratio.
The tip surface 32 of the above is joined to the annular step portion 33 over the entire surface.

The tip of the dome 2 is slidably fitted to the base of the liner 1. The outer diameter D2 of the dome 2 is formed smaller than the inner diameter d3 of the liner 1 at a predetermined ratio so that a predetermined gap is formed between the dome 2 and the liner 1 even when they are thermally expanded during operation of the gas turbine. It has become.

A metal seal ring 20 is interposed between the base end of the liner 1 and the dome 2. As shown in FIG.
The ring-shaped seal ring 20 is formed in a C-shape with the middle cut. The abutment ends 21 and 22 of the seal ring 20 are formed in a key shape that engages with each other so that no gap is formed at the joint with the liner 1.

The base end face 18 of the liner 1 has a seal ring 20.
It is joined to the one end face 23. The outer diameter D3 of the seal ring 20 is formed larger than the outer diameter D1 of the liner 1, and the base end face 18 of the liner 1 is joined to the end face 23 of the seal ring 20 over the entire surface.

The outer peripheral surface 27 of the dome 2 is the seal ring 20.
Is slidably fitted to the inner peripheral surface 24 of the. Outer diameter D of dome 2
2 is formed to be larger than the inner diameter d4 of the seal ring 20, and is set to have a dimensional relationship such that the seal ring 20 can be joined without a gap.

The seal ring 20 is attached to the base end portion 18 of the liner 1.
A plurality of metal plate springs 15 in the shape of strips are provided as the urging means for pressing against. The leaf springs 15 are arranged at equal intervals in the circumferential direction.

The base end of each leaf spring 15 is fixedly connected to the nozzle holder 5 via an annular flange 29. The tip of each leaf spring 15 is joined to the other end surface 25 of the seal ring 20 via an annular washer 30.

With the above construction, the operation will be described.

Due to the elastic restoring force of each leaf spring 15, the liner 1 is inserted into the inlet portion 14 of the scroll 8 via the seal ring 20.
The ceramic liner 1 is elastically supported by the engine casing 6 by being pressed against.

During operation of the gas turbine, since the dome 2 and the liner 1 are used in a high temperature atmosphere, a difference in thermal expansion of the ceramic liner 1 with respect to the metal dome 2 occurs. While the base end surface 18 of the slides in the radial direction with respect to the end surface 23 of the seal ring 20,
The outer peripheral surface 27 of the dome 2 is the inner peripheral surface 24 of the seal ring 20.
Is slid in the axial direction with respect to each other, and the two are relatively displaced to be absorbed. As a result, it is possible to prevent permanent deformation of the metal dome 2 and the like, and it is possible to prevent stress concentration on the ceramic liner 1 and damage.

The elastic restoring force of the leaf spring 15 pushes the base end surface 18 of the liner 1 against the seal ring 20, the tip end surface 32 of the liner 1 against the annular step 33 of the scroll 8, and a C-shaped seal ring. 20 is
The elastic restoring force ensures that the combustion chamber 11 is hermetically sealed by joining the outer surface 27 of the dome 2 with no gap.

Inner diameter d1 of the annular step portion 33 of the scroll 8
Is formed to be larger than the outer diameter D1 of the liner 1 and the inner diameter d2 of the annular step portion 33 is formed to be smaller than the inner diameter d3 of the liner 1 at a predetermined ratio. Even if both are eccentric within the range where they are fitted to the portion 14, the sealing performance is maintained.

The outer diameter D3 of the seal ring 20 is equal to that of the liner 1.
Since it is formed larger than the outer diameter D1 of the dome 2, even if both are eccentric within the range where the dome 2 fits with the liner 1,
The hermeticity is maintained.

The outer diameter D2 of the dome 2 is the inner diameter d of the liner 1.
By forming the dome 2 and the liner 1 in a predetermined ratio smaller than 3, the dome 2 and the liner 1 are thermally expanded during operation of the gas turbine. The gap is open, the outer peripheral surface 27 of the dome 2
Is not prevented from sliding in the axial direction with respect to the inner peripheral surface 24 of the seal ring 20.

Since the outer diameter D2 of the dome 2 is formed larger than the inner diameter d4 of the C-shaped seal ring 20, the outer peripheral surface 27 of the dome 2 slides on the inner peripheral surface 24 of the seal ring 20 without any gap. Movable fit.

The ceramic liner 1 is formed in a cylindrical shape that is axially symmetric with respect to the center line L, has a uniform thickness, is not machined, and has a portion whose cross-sectional shape changes abruptly. Since it does not exist, it is possible to prevent stress concentration from occurring during operation of the gas turbine, resulting in damage.

Further, since the ceramic liner 1 is formed in a cylindrical shape having a uniform thickness, cracking and deformation are suppressed from occurring during the molding and firing of the liner 1, and the productivity is improved, and the product is improved. The cost can be reduced.

Next, another embodiment shown in FIG. 3 will be described. It should be noted that the same parts as those in FIG.

The seal ring 20 is attached to the base end portion 18 of the liner 1.
A plurality of coil springs 41 having a coil shape are provided as a biasing unit that presses the coil springs against. The coil springs 41 are arranged at equal intervals in the circumferential direction.

Each coil spring 41 has its base end seated on the nozzle holder 5, and its tip end is joined to the end face 25 of the seal ring 20 via an annular washer 30.

In this case, the ceramic liner 1 is elastically supported with respect to the engine casing 6 by pressing the liner 1 against the inlet portion 14 of the scroll 8 via the seal ring 20 by the elastic restoring force of each coil spring 41. To be done.

Next, another embodiment shown in FIG. 4 will be described. It should be noted that the same parts as those in FIG.

The seal ring 20 is attached to the base end portion 18 of the liner 1.
A single coil spring 45 having a coil shape is provided concentrically with the dome 2, the swirler 3, and the like as an urging means for pressing against.

The base end of the coil spring 45 is seated on the nozzle holder 5, and the front end of the coil spring 45 is joined to the end face 25 of the seal ring 20 via an annular washer 30.

The coil spring 45 is wound in a conical shape so that the diameter gradually decreases from the base end to the tip.

In this case, the liner 1 is scrolled through the seal ring 20 by the elastic restoring force of the coil spring 45.
The ceramic liner 1 is elastically supported with respect to the engine casing 6 by being pressed against the inlet portion 14 of the.

[0056]

As described above, in the gas turbine combustor according to claim 1, the liner is axially pressed by the force of the biasing means via the seal ring, and the liner is against the engine casing. By being elastically supported, the hermeticity of the combustion chamber can be ensured, and it is possible to prevent stress concentration from occurring in the ceramic liner during operation of the gas turbine, resulting in damage. Further, it is not necessary to machine the liner, so that the productivity can be improved and the cost of the product can be reduced.

In the gas turbine combustor according to the second aspect, the liner is axially pressed by the elastic restoring force of the plurality of leaf springs via the seal ring, and the liner elastically moves with respect to the engine casing. Supported. Moreover, the cost of the product can be reduced by using the leaf spring.

In the gas turbine combustor according to the third aspect, the liner is axially pressed by the elastic restoring force of the plurality of coil springs via the seal ring, and the liner is elastically supported with respect to the engine casing. At the same time, the sealing performance is improved through the stable pressing force, and the deterioration of the combustion performance can be reliably prevented.

In the gas turbine combustor according to the fourth aspect, the liner is axially pressed through the seal ring by the elastic restoring force of the single coil spring, and the liner elastically moves against the engine casing. By being supported and using a single coil spring, the number of parts is reduced and the cost of the product is reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a combustor showing an embodiment of the present invention.

FIG. 2 is a front view of the seal ring.

FIG. 3 is a sectional view of a combustor showing another embodiment.

FIG. 4 is a sectional view of a combustor showing yet another embodiment.

FIG. 5 is a sectional view of a combustor showing a conventional example.

FIG. 6 is an enlarged cross-sectional view of portion A of FIG.

[Explanation of symbols]

 1 Liner 2 Dome 5 Nozzle Holder 6 Engine Casing 8 Scroll 11 Combustion Chamber 15 Leaf Spring 18 Liner Base End Surface 20 Seal Ring 27 Dome Outer Surface 33 Annular Step 41 Coil Spring 45 Coil Spring

Claims (4)

[Claims] 1. A gas turbine combustor comprising: a cylindrical ceramic liner defining a combustion chamber; and a bowl-shaped metal dome connected to the base end of the liner. A combustor for a gas turbine, comprising: a C-shaped seal ring slidably fitted to the outer peripheral surface; and a biasing means for pressing the seal ring against the base end surface of the liner. 2. The gas turbine combustor according to claim 1, wherein a plurality of strip-plate-shaped leaf springs are provided as the urging means. 3. The combustor for a gas turbine according to claim 1, further comprising a plurality of coil-shaped coil springs as the biasing means. 4. The combustor for a gas turbine according to claim 1, wherein a coil spring having a single coil shape is arranged concentrically with the dome as the biasing means.