Systems and methods for determining a target exhaust temperature for a gas turbine

• US 9,297,315 B2
• Filed: 09/28/2012
• Issued: 03/29/2016
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (GE Vernova, Inc.)
• Original Assignee: General Electric Company
• Inventors: Simons, Derrick, Dean, Douglas, Romoser, Carey, Wilkes, Kevin, Popovic, Predrag, Kulkarni, Abhijit
• Primary Examiner(s): Sung, Gerald L
• Assistant Examiner(s): WALTHOUR, SCOTT J
• Application Number:
  US13/630,610
• Publication Number:
  US 20140090353A1
• Time in Patent Office: 1,278 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: F02C 9/00 Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants controlling air intakes F02C7/057; controlling turbines F01D; controlling compressors F04D27/00; controlling in general G05
• CPC Class Codes: F02C 9/16 Control of working fluid flow F02C9/48 takes precedence; control of air-intake flow F02C7/057
• CPC Class Codes: F02C 9/26 Control of fuel supply F02C9/48 takes precedence; fuel valves F02C7/232
• CPC Class Codes: F02C 9/28 Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed F02C9/30 - F02C9/38, F02C9/44 take precedence
• CPC Class Codes: F05D 2270/08 to produce clean exhaust gases
• CPC Class Codes: F05D 2270/0831 indirectly, at the exhaust
• CPC Class Codes: F05D 2270/303 Temperature

Abstract

Embodiments of the invention can provide systems and methods for determining a target exhaust temperature for gas turbines. In one embodiment of the disclosure, there is disclosed a method for determining a target exhaust temperature for a gas turbine. The method can include determining a target exhaust temperature based at least in part on a compressor pressure condition; determining a temperature adjustment to the target exhaust temperature based at least in part on steam humidity; and changing the target exhaust temperature based at least in part on the temperature adjustment.

Claims

1. A method comprising:

determining a target exhaust temperature for a gas turbine engine comprising a compressor based at least in part on a compressor pressure condition;

determining a total flow rate comprising an air flow rate of the compressor and a steam flow rate of the compressor by multiplying a compressor discharge pressure by a constant;

determining the air flow rate by subtracting the steam flow rate from the total flow rate;

determining a water concentration by dividing the steam flow rate by the air flow rate;

determining a steam humidity by multiplying the water concentration by a calibration factor that is application specific;

determining a temperature adjustment to the target exhaust temperature based at least in part on the steam humidity;

changing the target exhaust temperature based at least in part on the temperature adjustment; and

applying the target exhaust temperature using a controller to set a fuel flow and/or air flow to a combustor of the gas turbine to achieve emissions requirements.

2. The method of claim 1, wherein determining the temperature adjustment is further based on at least one of a CO or NOx emissions reference condition.

3. The method of claim 1, wherein determining the temperature adjustment is further based at least in part on turbine ambient specific humidity.

4. The method of claim 1, wherein determining the temperature adjustment is further based at least in part on delta inlet pressure loss, current compressor condition, and delta exhaust temperature output.

5. The method of claim 1, wherein determining the temperature adjustment is further based at least in part on delta back pressure, current compressor condition, and delta exhaust temperature output.

6. The method of claim 1, further comprising:

generating a plurality of target exhaust temperatures; and

selecting one of the plurality of target exhaust temperatures to facilitate control of the gas turbine engine.

7. The method of claim 1, wherein the target exhaust temperature is applied by the controller to determine a turbine firing temperature.

8. The method of claim 1, wherein the method is repeated periodically during operation of the gas turbine.

9. An apparatus, comprising:

a gas turbine engine;

a controller comprising a computer processor; and

a memory in communication with the computer processor storing computer-executable instructions operable to, when executed by the computer processor, cause the computer processor to;

determine a target exhaust temperature for a gas turbine engine comprising a compressor based at least in part on a compressor pressure condition;

determine a total flow rate comprising an air flow rate of the compressor and a steam flow rate of the compressor by multiplying a compressor discharge pressure by a constant;

determine the air flow rate by subtracting the steam flow rate from the total flow rate;

determine a water concentration by dividing the steam flow rate by the air flow rate;

determine a steam humidity by multiplying the water concentration by a calibration factor that is application specific;

determine a temperature adjustment to the target exhaust temperature based at least in part on the steam humidity;

change the target exhaust temperature based at least in part on the temperature adjustment; and

apply the target exhaust temperature using the controller to set a fuel flow and/or air flow to a combustor of the gas turbine engine to achieve emissions requirements.

10. The apparatus of claim 9, wherein determining the temperature adjustment is further based on at least one of a CO or NOx emissions reference condition.

11. The apparatus of claim 9, wherein determining the temperature adjustment is further based at least in part on turbine ambient specific humidity.

12. The apparatus of claim 9, wherein determining the temperature adjustment is further based at least in part on delta inlet pressure loss, current compressor condition, and delta exhaust temperature output.

13. The apparatus of claim 9, wherein determining the temperature adjustment is further based at least in part on delta back pressure, current compressor condition, and delta exhaust temperature output.

14. The apparatus of claim 9, wherein the target exhaust temperature is applied by the controller to determine a turbine firing temperature.

15. The apparatus of claim 9, wherein the computer-executable instructions are executed periodically during operation of the gas turbine engine.

16. A system, comprising:

a gas turbine engine comprising one or more compressors, one or more combustors, or one or more turbines;

a steam source for injecting steam into pre-combustion, post-compression air;

a controller comprising a computer processor; and

a memory in communication with the computer processor storing computer-executable instructions operable to, when executed by the computer processor, cause the computer processor to;

determine a target exhaust temperature based at least in part on a compressor pressure condition;

determine a total flow rate comprising an air flow rate of the compressor and a steam flow rate of the compressor by multiplying a compressor discharge pressure by a constant;

determine the air flow rate by subtracting the steam flow rate from the total flow rate;

determine a water concentration by dividing the steam flow rate by the air flow rate;

determine a steam humidity by multiplying the water concentration by a calibration factor that is application specific;

determine a temperature adjustment to the target exhaust temperature based at least in part on the steam humidity;

change the target exhaust temperature based at least in part on the temperature adjustment; and

apply the target exhaust temperature using the controller to set a fuel flow and/or air flow to a combustor of the gas turbine engine to achieve emissions requirements.

17. The system of claim 16, wherein determining the temperature adjustment is further based on at least one of a CO or NOx emissions reference condition.