Modeling and control of gas cycle power plant operation with variant control profile

1. A method for operating a combined cycle power plant (CCPP), the method comprising:

operating the CCPP at an ambient condition and a load condition;

generating a power plant model of the CCPP for operating at the ambient condition and the load condition;

modeling a fuel consumption using a baseline control profile and the power plant model of the CCPP at the ambient condition and the load condition;

creating a variant control profile for the CCPP;

determining, using the power plant model, whether the variant control profile meets a quality threshold for the CCPP, the quality threshold including at least a fuel efficiency of the CCPP;

modifying the variant control profile in response to the variant control profile not meeting the quality threshold; and

adjusting the CCPP to use the variant control profile in response to the variant control profile meeting the quality threshold, wherein the variant control profile adjusts a turbine section inlet temperature schedule or an exhaust temperature schedule for the CCPP,

wherein adjusting the CCPP to use the variant control profile reduces an attemperator fluid flow within the CCPP during operation below a load output threshold for the CCPP and increases the attemperator fluid flow during operation above the load output threshold for the CCPP.

2. The method of claim 1 , wherein the load output threshold for the CCPP is approximately 87% of a maximum load output of the CCPP.

3. The method of claim 1 , wherein adjusting the CCPP to use the variant control profile includes adjusting an inlet guide vane (IGV) pitch angle within the CCPP.

4. The method of claim 1 , wherein adjusting the CCPP to use the variant control profile reduces an inlet bleed heat (IBH) flow of exhaust fluid from an exhaust section to an inlet section of a compressor of the CCPP.

5. The method of claim 1 , wherein adjusting the CCPP to use the variant control profile increases a steam output from a heat recovery steam generator (HRSG) assembly within the CCPP.

6. The method of claim 1 , wherein the quality threshold further includes at least a minimum heat rate reduction, a minimum plant efficiency increase, a minimum reduction to fuel consumption, a fuel consumption limit, an emissions limit, or an operating stability limit for the CCPP.

7. The method of claim 1 , further comprising:

modifying one of the load condition or the ambient condition of the CCPP; and

repeating the calculating, the creating, the determining, and one of the modifying of the variant control profile or the adjusting of the CCPP.

8. The method of claim 1 , wherein creating the variant control profile includes applying a predetermined temperature increase or temperature reduction to the baseline control profile, based on the ambient condition and the load condition.

9. The method of claim 1 , wherein the adjusted inlet temperature schedule and the adjusted exhaust temperature schedule of the CCPP are dependent on the load condition.

10. A program product stored on a computer readable storage medium for operating a combined cycle power plant (CCPP), the computer readable storage medium comprising program code for causing a computer system to perform actions including:

operating the CCPP at an ambient condition and a load condition;

generating a power plant model of the CCPP for operating at the ambient condition and the load condition;

modeling a fuel consumption using a baseline control profile and the power plant model of the CCPP at the ambient condition and the load condition;

creating a variant control profile for the CCPP;

determining, using the power plant model, whether the variant control profile meets a quality threshold for the CCPP, the quality threshold including at least a fuel efficiency of the CCPP;

modifying the variant control profile in response to the variant control profile not meeting the quality threshold; and

adjusting the CCPP to use the variant control profile in response to the variant control profile meeting the quality threshold, wherein the variant control profile adjusts a turbine section inlet temperature schedule or an exhaust temperature schedule for the CCPP,

wherein adjusting the CCPP to use the variant control profile reduces an attemperator fluid flow within the CCPP during operation below a load output threshold for the CCPP and increases the attemperator fluid flow during operation above the load output threshold for the CCPP.

11. The program product of claim 10 , wherein the load output threshold for the CCPP is approximately 87% of a maximum load output of the CCPP.

12. The program product of claim 10 , wherein adjusting the CCPP to use the variant control profile includes adjusting an inlet guide vane (IGV) pitch angle within the CCPP.

13. The program product of claim 10 , wherein adjusting the CCPP to use the variant control profile reduces an inlet bleed heat (IBH) flow of exhaust fluid from an exhaust section to an inlet section of a compressor of the CCPP.

14. The program product of claim 10 , wherein adjusting the CCPP to use the variant control profile increases a steam output from a heat recovery steam generator (HRSG) assembly within the CCPP.

15. The program product of claim 10 , wherein the quality threshold includes at least a minimum heat rate reduction, a minimum plant efficiency increase, a minimum reduction to fuel consumption, a fuel consumption limit, an emissions limit, or an operating stability limit for the CCPP.

16. A system comprising:

a combined cycle power plant (CCPP) having a gas turbine and a heat recovery steam generator (HRSG); and

a system controller in communication with the gas turbine and the HRSG of the CCPP, the system controller being operable to:

operate the CCPP at an ambient condition and a load condition;

generate a power plant model of the CCPP for operating at the ambient condition and the load condition;

model a fuel consumption using a baseline control profile and the power plant model of the CCPP at the ambient condition and the load condition;

create a variant control profile for the CCPP;

determine, using the power plant model, whether the variant control profile meets a quality threshold for the CCPP, the quality threshold including at least a fuel efficiency of the CCPP;

modify the variant control profile in response to the variant control profile not meeting the quality threshold; and

adjust the CCPP to use the variant control profile in response to the variant control profile meeting the quality threshold, wherein the variant control profile adjusts a turbine section inlet temperature schedule or an exhaust temperature schedule for the CCPP,

wherein adjusting the CCPP to use the variant control profile reduces an attemperator fluid flow within the CCPP during operation below a load output threshold for the CCPP and increases the attemperator fluid flow during operation above the load output threshold for the CCPP.

17. The system of claim 16 , wherein the load output threshold for the CCPP is approximately 87% of a maximum load output of the CCPP.

18. The system of claim 16 , wherein the system controller adjusting the CCPP to use the variant control profile adjusts an inlet guide vane (IGV) pitch angle within the CCPP.

19. The system of claim 16 , wherein the system controller adjusting the CCPP to use the variant control profile increases a steam output from a heat recovery steam generator (HRSG) assembly within the CCPP.

20. The system of claim 16 , wherein the quality threshold includes at least a minimum heat rate reduction, a minimum plant efficiency increase, a minimum reduction to fuel consumption, a fuel consumption limit, an emissions limit, or an operating stability limit for the CCPP.