Sequential combustion with dilution gas mixer

Patent metadata

Field	Value
Publication number	US-10634357-B2
Application number	US-201715823939-A
Country	US
Kind code	B2
Filing date	Nov 28, 2017
Priority date	Aug 24, 2012
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

The invention refers to a sequential combustor arrangement comprising a first burner, a first combustion chamber, a mixer for admixing a dilution gas via a dilution gas inlet to the hot gases leaving the first combustion chamber during operation, a second burner, and a second combustion chamber arranged sequentially in a fluid flow connection. The sequential combustor arrangement further includes four cooling zones with a cooling channel. During operation a cooling gas flows through the cooling channels. The disclosure further refers to a method for operating a gas turbine with such a sequential combustor arrangement.

First claim

The invention claimed is:

1. A sequential combustor arrangement comprising:
a first burner;
a first combustion chamber;
a mixer for admixing a dilution gas to the hot gases leaving the first combustion chamber during operation;
a second burner; and
a second combustion chamber arranged sequentially in a fluid flow connection, wherein the mixer is configured to guide combustion gases in a hot gas flow path extending between the first combustion chamber and the second burner;
the mixer having a duct with an inlet at an upstream end configured for connection to the first combustion chamber and an outlet at a downstream end configured for connection to the second burner;
a first combustion chamber cooling zone with a first cooling channel which is delimited by a first combustion chamber wall and a first jacket, which encloses the first combustion chamber wall;
a mixer cooling zone with a second cooling channel which is delimited by a mixer wall and a second jacket, which encloses the mixer wall;
a second burner cooling zone with a third cooling channel which is delimited by a second burner wall and a third jacket, which encloses the second burner wall; and
a second combustion chamber cooling zone, with a fourth cooling channel which is delimited by a second combustion chamber wall and a fourth jacket, which encloses the second combustion chamber wall, the first, second, third, and fourth cooling channels being arranged such that a cooling gas will flow through the cooling channels during operation;
the mixer having a dilution gas inlet directly connected to at least one exit of the compressor such that a first portion of compressed gas leaving the compressor will be admitted directly to the dilution gas inlet as a portion of the dilution gas without prior heat pick up in a cooling zone during operation;
wherein the fourth cooling channel is connected to the at least one exit of the compressor to receive a second portion of the compressed gas from the compressor as a portion of the cooling gas to cool the second combustion chamber wall and subsequently pass the second portion of the compressed gas to the third cooling channel to cool the second burner wall during operation; and
wherein the second cooling channel is connected to the at least one exit of the compressor such that a third portion of the compressed gas is passable into the second cooling channel as a portion of the cooling gas to cool the mixer wall during operation and the first cooling channel is connected adjacent to the dilution gas inlet such that at least some of the dilution gas bypasses the dilution gas inlet and passes to the first cooling channel to cool the first combustion chamber wall during operation.

2. The sequential combustor arrangement of claim 1 , wherein the third cooling channel is connected to the mixer to feed the second portion of the compressed gas to the mixer as a portion of the dilution gas to be admixed with the hot gases during operation; and/or
wherein the second cooling channel is connected to the mixer so that some of the third portion of the compressed gas is passable from the second cooling channel to the mixer as a portion of the dilution gas for admixing with the hot gases during operation.

3. The sequential combustor arrangement of claim 1 , wherein at least three of the first, second, third, and fourth cooling channels are fluidly connected to each other in a row such that at least part of the cooling gas used for cooling in one cooling channel will be further used for sequentially cooling the other two cooling channels during operation.

4. The sequential combustor arrangement of claim 1 , wherein the at least two cooling channels of the first, second, third, and fourth cooling channels are directly connected to the exit of the compressor such that compressed gas leaving the compressor will be admitted directly to the at least two cooling channels without prior heat pick up in an interposed cooling zone.

5. The sequential combustor arrangement of claim 1 , wherein the second cooling channel is connected to the mixer so that some of the third portion of the compressed gas is passable from the second cooling channel into the mixer as a portion of the dilution gas for admixing with the hot gases from the first combustion chamber during operation.

6. The sequential combustor arrangement as claimed in claim 1 , wherein at least one cooling channel of the first, second, third, and fourth cooling channels has an inlet at a downstream end with respect to a flow direction of hot gas and an outlet opening at an upstream end with respect to the flow direction of the hot gas and wherein at least part of the cooling gas flows in a counter flow to the hot gas flow direction during operation.

7. A method for operating a gas turbine with at least a compressor, a sequential combustor arrangement having a first burner, a first combustion chamber, a mixer for admixing a dilution gas to hot gases leaving the first combustion chamber, a second burner, and a second combustion chamber arranged sequentially in a fluid flow connection, the method comprising:
guiding, via the mixer combustion gases in a hot gas flow path extending between the first combustion chamber and the second burner via a duct having an inlet at an upstream end configured for connection to the first combustion chamber and an outlet at a downstream end configured for connection to the second burner, the sequential combustor arrangement including a first combustion chamber cooling zone with a first cooling channel which is delimited by a first combustion chamber wall and a first jacket, which encloses the first combustion chamber wall, a mixer cooling zone with a second cooling channel which is delimited by a mixer wall and a second jacket, which encloses the mixer wall, a second burner cooling zone with a third cooling channel which is delimited by a second burner wall and a third jacket, which encloses the second burner wall, and a second combustion chamber cooling zone, with a fourth cooling channel which is delimited by a second combustion chamber wall and a fourth jacket, which encloses the second combustion chamber wall, the method comprising:
feeding and guiding a cooling gas through the cooling channels, the feeding and guiding of the cooling gas through the cooling channels including:
feeding a first portion of compressed gas from the compressor to the fourth cooling channel as a portion of the cooling gas to cool the second combustion chamber wall and subsequently passing the second portion of the compressed gas to the third cooling channel to cool the second burner wall, and
feeding a second portion of the compressed gas into the second cooling channel as a portion of the cooling gas to cool the mixer wall; and

admixing the dilution gas to the hot gases leaving the first combustion chamber in the mixer, the admixing of the dilution gas including:
feeding a third portion of the compressed gas to a dilution gas inlet of the mixer without prior heat pick up in a cooling zone during operation; and bypassing a portion of the dilution gas past the dilution gas inlet to an adjacent inlet of the first cooling channel to cool the first combustion chamber wall.

8. The method of claim 7 , wherein at least part of the cooling gas in a cooling channel flows in a counter flow to a hot gas flow direction, and/or at least part of the cooling gas in a cooling channel flows in a co-current flow to the hot gas flow direction.

9. The method of claim 8 , wherein the mixer has a dilution gas exit connected to the compressor so that the third portion of the compressed gas passes from the compressor to the mixer for admixing without contacting the first combustion chamber wall, without contacting th

Assignees

• Ansaldo Energia Switzerland AG

Inventors

• Freitag Ewald
• Eroglu Adnan
• Maurer Michael
• Stuttaford Peter

Classifications

• F23R3/20

  incorporating fuel injection means · CPC title

• F23R3/346

  for staged combustion · CPC title

• F23R2900/00014

  Reducing thermo-acoustic vibrations by passive means, e.g. by Helmholtz resonators · CPC title

• F02C7/22

  Fuel supply systems · CPC title

• F23R3/06 Primary

  Arrangement of apertures along the flame tube · CPC title