# US 9,752,504 B2 · Method for operating a gas turbine plant and gas turbine plant for implementing the method

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- Number: US 9,752,504 B2
- Document ID: US9752504B2
- Status: Granted
- Kind: B2
- Application number: 13/589,494
- Filed: 2012-08-20
- Published: 2013-03-21
- Granted: 2017-09-05
- Earliest claimed: 2011-08-22
- Assignees: Ansaldo Energia IP UK Limited
- Applicants: Manuel Arias Chao; Bernhard Wippel; Christian Balmer; Ralf Jakoby
- Inventors: Manuel Arias Chao; Bernhard Wippel; Christian Balmer; Ralf Jakoby
- Web page: https://patentgrep.com/patent/US9752504B2

## CPC

- F01D 15/12: Combinations with mechanical gearing (driven by multiple engines F01D13/00)
- F02C 7/185: {Cooling means for reducing the temperature of the cooling air or gas}
- F02C 6/08: the gas being bled from the gas-turbine compressor
- F02C 7/18: the medium being gaseous, e.g. air {(F02C7/125 takes precedence)}
- F02C 9/18: by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)}
- F05D 2260/20: Heat transfer, e.g. cooling
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

A method is provided for operating a gas turbine plant including a compressor, which on an inlet side inducts intake air and compresses it, providing compressor exit air on a discharge side. The plant also includes a combustion chamber where fuel is combusted, using compressor exit air, forming a hot gas; and a turbine, where the hot gas is expanded, performing work. The method includes extracting compressed air from the compressor, directing it as cooling air flow into the combustion chamber and/or into the turbine for cooling thermally loaded components. The method also includes controlling at least one cooling air flow, for achieving specific operating targets, using a control element depending on an operating target. A gas turbine plant is also provided having at least one control element for cooling air flow control, and a gas turbine controller which controls the gas turbine plant based on selectable control parameter sets.

## Claims

### Claim 1

A method for operating a gas turbine plant, comprising a compressor, which on an inlet side inducts intake air through variable inlet guide vanes and compresses it for providing compressor exit air on a discharge side, a combustion chamber, in which a fuel is combusted, using the compressor exit air, forming a hot gas, and a turbine, in which the hot gas is expanded, performing work, the method comprising:
closing the variable inlet guide vanes to a minimum position during a low partial load operation;
extracting compressed air from the compressor and directing the compressed air as cooling air flow into the combustion chamber and/or into the turbine for cooling thermally loaded components; and
controlling an intermediate-pressure cooling air flow and/or a low-pressure cooling air flow during the low partial load operation for cooling thermally loaded components in the combustion chamber and/or in the turbine as a function of the turbine exhaust temperature to maintain turbine exhaust temperature above a turbine exhaust temperature (TAT) limit and as a function of inlet conditions into a heat recovery boiler.

### Claim 2 (depends on 1)

The method as claimed in claim 1, wherein the cooling air flow for cooling thermally loaded components of the combustion chamber and/or of the turbine is also controlled as a function of the compressor exit pressure.

### Claim 3 (depends on 2)

The method as claimed in claim 2, wherein at low ambient temperature the cooling air flow for cooling thermally loaded components of the combustion chamber and/or of the turbine is increased in order to reduce the compressor exit pressure.

### Claim 4 (depends on 1)

The method as claimed in claim 1, wherein at low partial load the intermediate-pressure cooling air flow and/or the low-pressure cooling air flow for cooling thermally loaded components of the combustion chamber and/or of the turbine is reduced as a function of the turbine exhaust temperature (TAT) in order to keep the turbine exhaust temperature (TAT) constant.

### Claim 5 (depends on 4)

The method as claimed in claim 4, wherein regardless of the turbine exhaust temperature (TAT) the intermediate-pressure cooling air flow and/or the low-pressure cooling air flow is not reduced below a minimum flow.

### Claim 6 (depends on 1)

The method as claimed in claim 1, wherein regardless of the turbine exhaust temperature (TAT) the intermediate-pressure cooling air flow and/or the low-pressure cooling air flow is not reduced below a minimum flow.

### Claim 7 (depends on 1)

The method as claimed in claim 1, wherein a recooling temperature of a recooler, in which the cooling air flow is recooled, is controlled in dependence upon a cooling air flow.

### Claim 8 (depends on 1)

The method as claimed in claim 1, wherein the turbine exhaust temperature (TAT) is kept above a turbine exhaust temperature limit during a partial load operation at less than 40% of full load.

### Claim 9 (depends on 8)

The method as claimed in claim 8, wherein the turbine exhaust temperature (TAT) is kept above a turbine exhaust temperature limit during a partial load operation at less than 25% of full load.

### Claim 10 (depends on 1)

The method as claimed in claim 1, wherein the cooling air consumption during a partial load operation is reduced relative to cooling air consumption at full load for maintaining the turbine exhaust temperature (TAT) above the turbine exhaust temperature (TAT) limit.

### Claim 11 (depends on 1)

The method as claimed in claim 1, wherein the extracted compressed air is directed into the combustion chamber and the turbine, and wherein a gas turbine controller is configured to control the intermediate-pressure cooling air flow and/or the low pressure cooling air flow for cooling thermally loaded components in the combustion chamber and in the turbine as a function of the turbine exhaust temperature (TAT) in order to keep the turbine exhaust temperature (TAT) above the turbine exhaust temperature (TAT) limit.

### Claim 12

A gas turbine plant comprising a compressor, which on an inlet side inducts intake air through variable inlet guide vanes and compresses it for providing compressor exit air on a discharge side, a combustion chamber, in which a fuel is combusted, using the compressor exit air, forming hot gas, a turbine, in which the hot gas is expanded, performing work, wherein for cooling thermally loaded components of the combustion chamber and/or of the turbine a cooling air flow is directed from the compressor and/or from the exit of the compressor to the thermally loaded components, and at least one control element for controlling the cooling air flow, and a gas turbine controller, in which the control parameters for realizing a conventional operating concept are stored, and at least one additional set of control parameters, which is selected by an operator for realizing a specific operating concept, is stored in the gas turbine controller; wherein the gas turbine controller is configured to close the variable inlet guide vanes during a low partial load operation to a minimum position and to control an intermediate-pressure cooling air flow and/or a low pressure cooling air flow during the low partial load operation for cooling thermally loaded components in the combustion chamber and/or in the turbine as a function of the turbine exhaust temperature (TAT) in order to keep the turbine exhaust temperature (TAT) above a turbine exhaust temperature (TAT) limit and as a function of inlet conditions into a heat recovery boiler.

### Claim 13 (depends on 12)

The gas turbine plant as claimed in claim 12, wherein at least one control element has a minimum opening which ensures a minimum cooling air flow to the thermally loaded components.

### Claim 14 (depends on 13)

The gas turbine plant as claimed in claim 13, wherein at least one thermally loaded component comprises cooling air openings having a throughflow capacity which is at least 30% greater than a throughflow capacity which is required for achieving a design service life at a design point at full load.

### Claim 15 (depends on 12)

The gas turbine plant as claimed in claim 12, wherein at least one thermally loaded component comprises cooling air openings having a throughflow capacity which is at least 30% greater than a throughflow capacity which is required for achieving a design service life at a design point at full load.