Systems and methods for improved combined cycle control
Systems and methods for improved control of a turbomachine system with a bottoming cycle system are presented. The systems and methods include a controller that utilizes modeling techniques to derive a plurality of load path curves. The controller utilizes a current load path, a minimum load path, and a constant efficiency load path. The systems and methods include a control process configured to receive a user input representative of a life cycle control modality and to execute a control action based on deriving a load efficiency by applying the current load path, the minimum load path, the constant efficiency load path, or a combination thereof, and the life cycle control modality. The control action is applied to control the turbomachine system and the bottoming cycle system fluidly coupled to the turbomachine system. Further, the life cycle control modalities may be selected by a user based upon known tradeoffs.
1. A system comprising:
a controller comprising:
a memory storing:
a current load path;
a minimum load path;
a constant efficiency load path; and
a processor configured to execute a control process, wherein
the control process is configured to receive a user input representative of a life cycle control modality and to execute a control action based on deriving a load efficiency by applying the current load path, the minimum load path, the constant efficiency load path, or a combination thereof, and the life cycle control modality, wherein the control action is applied to control a turbomachine system and a bottoming cycle system fluidly coupled to the turbomachine system.
2. The system of claim 1 , wherein the bottoming cycle system comprises a heat recovery steam generation (HRSG) system, a steam turbine system, a cooling tower system, or a combination thereof.
3. The system of claim 2 , wherein the HRSG system comprises an attemperation system having a spraying system fluidly coupled to a boiler of the HRSG system, and the control action controls the spraying system.
4. The system of claim 1 , wherein the constant efficiency load path comprises a lowest Tfire set point with minimal or no impact on combined cycle gas turbine efficiency.
5. The system of claim 1 , wherein the life cycle control modality comprises running a gas turbine at lowest firing temperature with minimal or no impact on combined cycle gas turbine (CCGT) efficiency, with improved CCGT efficiency, with improved hot gas path life, with improved profit, with a desired percentage impact on CCGT efficiency, with lower attemperation flow, or a combination thereof.
6. The system of claim 1 , wherein the minimum load path comprises running the turbomachine system at lowest firing temperature while respecting carbon oxide and lean blow-out boundaries.
7. The system of claim 1 , wherein the control process comprises modeling the turbomachine system and the bottoming cycle system with a firing temperature (Tfire) reduction model using a plurality of factors based on the life cycle modality input.
8. The system of claim 7 , wherein the models are generated with physics-based modeling techniques comprising low cycle fatigue (LCF) life prediction modeling, computational fluid dynamics (CFD), finite element analysis (FEA), solid modeling, 2-dimension to 3-dimension FEA mapping, or any combination thereof.
9. The system of claim 7 , wherein the plurality of factors comprise steam temperature, steam temperature set points, attemperation flow, inlet guide vane angle position, gas turbine exhaust temperature, or any combination thereof.
10. The system of claim 1 , wherein the control process is configured to generate operating boundaries comprising carbon oxide, nitrous oxide, lean blow out, heat recovery steam generation (HRSG) exhaust temperature, and HRSG drum pressure limit.
11. The system of claim 1 , wherein the constant efficiency load path is generated via non-linear optimization constraint analysis.
12. A computer-readable medium storing non-transitory computer instructions, the instructions configured to:
provide a current load path;
provide a minimum load path;
provide a constant efficiency load path;
receive a user input representative of a life cycle control modality for a turbomachinery; and
execute a control action based on deriving a load efficiency by applying the current load path, the minimum load path, the constant efficiency load path, or a combination thereof, and the life cycle control modality, wherein the control action is applied to control a turbomachine system and a bottoming cycle system fluidly coupled to the turbomachine system.
13. The computer-readable medium storing non-transitory computer instructions of claim 12 , wherein the constant efficiency load path represents a lowest firing temperature of the turbomachine with minimal or no impact on combined cycle gas turbine efficiency.
14. The computer-readable medium storing non-transitory computer instructions of claim 12 , wherein the life cycle control modality comprises operating a gas turbine at a lowest firing temperature with minimal or no impact on combined cycle gas turbine (CCGT) efficiency, with improved CCGT efficiency, with improved hot gas path life, with improved profit, with a desired percentage impact on CCGT efficiency, with lower attemperation flow, or a combination thereof.
15. The computer-readable medium storing non-transitory computer instructions of claim 12 , wherein the load efficiency is derived by modeling the turbomachine system and the bottoming cycle system with a firing temperature (Tfire) reduction model using a plurality of factors depending on the life cycle modality input.
16. The computer-readable medium storing non-transitory computer instructions of claim 15 , wherein the plurality of factors comprise steam temperature, steam temperature set points, attemperation flow, inlet guide vane angle position, gas turbine exhaust temperature, or any combination thereof.
17. The computer-readable medium storing non-transitory computer instructions of claim 12 , wherein deriving the load efficiency comprises generating a firing temperature reduction set point to apply throughout a load path.
18. A method comprising:
providing, via a controller, a current load path;
providing, via the controller, a minimum load path;
providing, via the controller, a constant efficiency load path;
providing, via the controller, constraints;
receiving, via the controller, a user input representative of a life cycle control modality for a turbomachinery;
executing, via the controller, non-linear analysis;
utilizing, via the controller, sensor data and deriving load path curves; and
executing, via the controller, a control action using one of the derived load path curves based on deriving a load efficiency by applying the current load path, the minimum load path, the constant efficiency load path, or a combination thereof, the life cycle control modality, and the constraints, wherein the control action is applied to control a turbomachine system and a bottoming cycle system fluidly coupled to the turbomachine system.
19. The method of claim 18 , wherein the constraints comprise carbon oxide, nitrous oxide, lean blow-out, heat recovery steam generation (HRSG) exhaust temperature, and HRSG drum pressure limit.
20. The method of claim 18 , wherein the life cycle control modality comprises operating a gas turbine at the lowest firing temperature with minimal or no impact on combined cycle gas turbine (CCGT) efficiency, with improved CCGT efficiency, with improved hot gas path life, with improved profit, with a desired percentage impact on CCGT efficiency, with lower attemperation flow, or a combination thereof.