JPH08303781A - Gas turbine combustor - Google Patents

Abstract

PURPOSE: To provide a gas turbine combustor which achieves a higher cooling performance of a tail cylinder of a combustor to allow maintaining of sufficient endurance and reliability even in application for a high temperature gas turbine. CONSTITUTION: In a combustor for a gas turbine in which an air passage for combustion is formed between a liner outer cylinder and a liner inner cylinder, a combustion chamber is defined in the liner inner cylinder and a tail cylinder 20 is provided in the liner inner cylinder to guide a combustion gas, the tail cylinder 20 is built in a double cylinder structure comprising an outer cylinder 22 of the tail cylinder and an inner cylinder 21 of the tail cylinder and a circular part thereof is formed into a cooling passage 23 leading to the air passage for combustion and a plurality of cooling fins 24 are arranged radially in the cooling passage 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine combustor used in a gas turbine power plant, and more particularly to improvement of a cooling structure of a combustor transition piece.

[0002]

2. Description of the Related Art In a gas turbine power plant, discharge air compressed by driving a compressor provided coaxially with a gas turbine is guided to a gas turbine combustor as combustion air and burned with fuel in the combustor. The combustion gas is guided from the inner cylinder of the combustor to the gas turbine to drive the gas turbine to perform work.

A conventional gas turbine combustor 1 has a structure shown in FIG. 3, a plurality of gas turbine combustors 1 are provided between a compressor 2 and a gas turbine 3, and are housed in a discharge chamber 4 from the compressor 2. The gas turbine combustor 1 includes an outer cylinder 5 and an inner cylinder 6,
A combustion air flow path 7 is formed therebetween, while a combustion chamber 8 is defined in the inner cylinder 6, and fuel is mixed with combustion air in the combustion chamber 8 and burned.

Combustion gas resulting from combustion of fuel is combustor transition piece 9
The gas turbine 3 is guided through the inside to the inlet of the gas turbine 3 to drive and work.

[0005]

The tail pipe 9 of the gas turbine combustor 1 is fitted to the rear end of the inner pipe and elastically held by a leaf spring or the like, and is discharged by the compressed air by the compressor 2. The structure is cooled. However, in this transition piece cooling structure, the convective cooling in which the outer surface of the transition piece 9 is cooled by the convection of the air discharged from the compressor is the mainstream. In this case, the temperature of the transition piece 9 exposed to the high-temperature combustion gas exceeds the technically compatible temperature (about 800 ° C.) of the transition piece material, which may reduce the durability and reliability of the gas turbine combustor. there were.

The present invention has been made in consideration of the above circumstances, and it is possible to improve the cooling performance of the combustor transition piece and maintain sufficient durability and reliability even when applied to a high temperature gas turbine. An object of the present invention is to provide a gas turbine combustor that can be used.

[0007]

In order to achieve the above-mentioned object, the present invention forms a combustion air passage between an outer cylinder of a liner and an inner cylinder of a liner, and forms a combustion chamber in the inner cylinder of the liner. A gas turbine combustor that defines a transition piece that guides combustion gas in the liner inner cylinder, wherein the transition piece has a double tube structure composed of an outer transition piece and an inner transition piece, The annular portion is formed in a cooling flow passage communicating with the combustion air flow passage, and a plurality of cooling fins are radially arranged in the cooling flow passage.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a gas turbine combustor according to the present invention will be described below with reference to FIGS. 1 and 2.

The gas turbine combustor 10 according to the present invention is provided between a compressor 11 and a gas turbine 13 that drives a generator 12, and is provided in a chamber casing (not shown) that defines a discharge chamber from the compressor 11. Be accommodated. The chamber casing includes a compressor 11 and a gas turbine 13.
The casings are integrally or integrally connected, and a plurality of gas turbine combustors 10, for example, 10 or 14 are arranged in the chamber casing in the circumferential direction.

Each gas turbine combustor 10 is formed in a double-cylinder structure from a liner outer cylinder 15 and an inner cylinder 16 constituting a combustor body, and its annular space is defined as a combustion air flow passage 17. A combustion chamber 18 is defined in the liner inner cylinder 16, and fuel and combustion air are supplied into the combustion chamber 18 for combustion.

On the other hand, a transition piece 20 is attached to the rear end of the inner cylinder of the gas turbine combustor 10. The tail cylinder 20 is the inner cylinder 21 of the tail cylinder.
And a transition piece outer cylinder 22, and an annular space therebetween is defined as a cooling flow path 23. A plurality of cooling fins 24 also serving as a reinforcement are radially arranged in the cooling flow path 23 to increase a heat transfer area (heat exchange area) in the cooling flow path 23 and accelerate heat dissipation. ing. The tail cylinder inner cylinder 21 is loosely fitted to the rear end of the liner inner cylinder 18 of the combustor body, and elastically held by a leaf spring or the like. The inside of the tail cylinder inner cylinder 21 is formed as a guide path 25 for guiding the combustion gas burned in the combustion chamber 18 to the inlet of the gas turbine 13.

The cooling passage 23 formed in the transition piece 20 has a tail end side formed as an inflow port 23a, and its outflow side is opened to the combustion air passage 17 and the combustion gas passing through the inside of the transition piece inner tube 21. The heat-exchanged cooling discharge air is guided to the combustion air flow path 17.

Next, the operation of the gas turbine combustor 10 will be described.

The high-pressure discharge air compressed by driving the compressor 11 of the gas turbine power plant is discharged into the discharge chamber, and a part of the discharge chamber is cooled by the cooling passage 23.
Then, the rest is guided to the combustion air flow path 17. The air guided to the combustion air flow path 17 continues to flow into the liner inner cylinder 16
It is introduced into the internal combustion chamber 18 and mixed with the fuel that is separately guided into the combustion chamber 18 to be burned to form high-temperature combustion gas. This combustion gas is guided to the gas turbine 13 through a guide passage 25 formed in the inner cylinder 21 of the transition piece. As the combustion gas passes through the gas turbine 13, it expands and does work,
The generator 12 is driven to rotate. The combustion gas that has worked in the gas turbine 13 is exhausted.

On the other hand, since the high temperature combustion gas is guided inside the tail cylinder inner cylinder 21, the temperature becomes high, but the tail cylinder 20 becomes the tail cylinder outer cylinder 2
2 and the inner cylinder 21 are formed in a double cylinder structure, and a cooling flow path 23 is formed inside. The cooling air is accelerated when being guided from the discharge chamber into the cooling flow path 23, and the flow velocity is For example, it increases from about 10 m / sec to about 40 m / sec. As a result, the heat dissipation efficiency of the surface of the inner cylinder of the transition piece is improved, the heat transfer coefficient of the surface of the inner tube of the transition piece becomes good, and the inner tube 21 of the transition piece is positively cooled. Therefore, although the pressure loss of the cooling air through the cooling flow path 23 increases, the metal temperature of the transition piece 20 can be lowered to the allowable temperature or lower.

By providing the cooling fins 24 in the cooling passage 23 in order to increase the heat transfer area, it is possible to further improve the heat radiation efficiency on the surface of the inner cylinder of the transition piece. Even if the vessel 10 is applied to a high temperature gas turbine, the temperature of the transition piece inner cylinder 21 can be lowered to a temperature that can be sufficiently withstood by existing combustion materials, for example, to about 700 ° C.

Further, as shown in FIG. 1, a large number of cooling air holes 27 may be formed in the transition piece outer cylinder 22, for example, in a plurality of rows in the circumferential direction or randomly as needed. When a large number of cooling air holes are formed, the axial flow passage cross-sectional area in the cooling pipe 23 of the transition piece is appropriately determined based on the cooling performance calculation of the combustor.

In the embodiment of the present invention, the liner outer cylinder is extended to the tail cylinder side, and the tail cylinder outer cylinder is inserted into the liner outer cylinder to form the overlapping portion. An axial gap may be formed between the liner outer cylinder and the tail cylinder outer cylinder, or the tail cylinder outer cylinder may be integrally or integrally connected to the liner outer cylinder.

[0019]

As described above, in the gas turbine combustor according to the present invention, the tail cylinder provided in the liner inner cylinder has a double cylinder structure composed of the tail cylinder outer cylinder and the tail cylinder inner cylinder. Since the annular portion is formed in the cooling passage communicating with the combustion air flow passage, the compressed air discharged into the discharge chamber is accelerated when passing through the cooling passage to improve the heat transfer efficiency, and the surface of the inner cylinder of the transition piece. To actively and effectively cool. Compressed air that has cooled the inner surface of the tail cylinder is guided into the combustion air flow path, so the surface of the inner cylinder of the tail cylinder is always cooled by new compressed air for cooling, and the cooling performance of the combustor tail cylinder is improved. Even if this gas turbine combustor is applied to a high temperature gas turbine, sufficient durability and reliability can be ensured. Moreover, by providing the cooling fins in the cooling flow passage, the heat transfer area can be increased, and thereby the heat dissipation efficiency of the surface of the inner cylinder of the transition piece can be further improved.
Even if this gas turbine combustor is applied to a high temperature gas turbine, the temperature of the inner cylinder of the transition piece can be lowered to a temperature not higher than the temperature at which the existing combustion material can sufficiently withstand.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a transition piece structure showing an embodiment of a gas turbine combustor according to the present invention.

FIG. 2 is a view taken along line II-II in FIG.

FIG. 3 is a diagram showing a gas turbine combustor attached to a gas turbine.

[Explanation of symbols]

 10 Gas Turbine Combustor 11 Compressor 13 Gas Turbine 15 Liner Outer Cylinder 16 Liner Inner Cylinder 17 Combustion Air Flow Path 18 Combustion Chamber 20 Tail Cylinder 21 Tail Cylinder Inner Cylinder 22 Tail Cylinder Outer Cylinder 23 Cooling Channel 24 Cooling Fin 25 Combustion gas guide way 27 Cooling air hole

Claims (2)

[Claims] 1. A liner outer cylinder and a liner inner cylinder are formed with a combustion air flow path to define a combustion chamber in the liner inner cylinder, and a tail cylinder for guiding combustion gas is formed in the liner inner cylinder. In the gas turbine combustor provided in, the transition piece is constituted by a transition piece outer cylinder and a transition piece inner cylinder in a double-cylinder structure, and the annular portion thereof serves as a cooling flow path leading to the combustion air flow path. Formed,
A gas turbine combustor, wherein a plurality of cooling fins are radially arranged in the cooling flow path. 2. The tail cylinder outer cylinder is provided with a large number of cooling air holes, and the tail cylinder inner cylinder is configured to be capable of impingement cooling.
A gas turbine combustor as described.