초록 ▼

A method and system for controlling combustion in a gas turbine engine (10) includes reducing an overall fuel flow provided to a stage (22) of burners (e.g. 34, 35) of the gas turbine engine until reaching a predetermined dynamic operating condition of the first burner of the stage. The method also

A method and system for controlling combustion in a gas turbine engine (10) includes reducing an overall fuel flow provided to a stage (22) of burners (e.g. 34, 35) of the gas turbine engine until reaching a predetermined dynamic operating condition of the first burner of the stage. The method also includes maintaining, while continuing to reduce the overall fuel flow (e.g. 30), a first portion (e.g. 36), of the overall fuel flow delivered to the first burner at a maintenance level so that the predetermined dynamic operating condition of the first burner is maintained.

대표청구항 ▼

What is claimed is: 1. A method for controlling combustion in a gas turbine engine comprising: monitoring dynamic operating conditions for each of the burners in a stage with a plurality of burners of a gas turbine using a dynamic condition sensor; reducing an overall fuel flow provided to the stag

What is claimed is: 1. A method for controlling combustion in a gas turbine engine comprising: monitoring dynamic operating conditions for each of the burners in a stage with a plurality of burners of a gas turbine using a dynamic condition sensor; reducing an overall fuel flow provided to the stage of burners of the gas turbine engine until reaching a predetermined dynamic operating condition of a first burner of the stage using a controller to control a stage fuel flow valve, the predetermined operating condition exhibiting a predetermined degree of dynamic instability; and maintaining a first mass flow rate of fuel delivered to the first burner at a maintenance level using the controller, a first burner flow sensor, and a first burner flow valve, so that the predetermined dynamic operating condition of the first burner is maintained while continuing to reduce the overall fuel flow to the stage via the stage fuel flow valve. 2. The method of claim 1, comprising: further reducing the overall fuel flow via the stage fuel flow valve until reaching a predetermined dynamic operating condition of a second burner of the stage; and maintaining a second mass flow rate of fuel delivered to the second burner using the controller, a second burner flow sensor, and a second burner flow valve, so that the predetermined dynamic operating condition of the second burner is maintained while continuing to reduce the overall fuel flow. 3. The method of claim 1, further comprising, when the predetermined dynamic operating condition of the first burner is reached, increasing the first mass flow rate to provide a desired operating margin away from the predetermined dynamic operating condition using the controller and at least one of the stage fuel flow valve and the first burner flow valve. 4. The method of claim 1, wherein the method is implemented only when the gas turbine engine is being operated in a load range of about 40% to 100% of a base load rating of the gas turbine engine. 5. The method of claim 1, further comprising performing the steps of claim 1 responsive to a change in an operating environment of the gas turbine engine. 6. The method of claim 1, further comprising performing the steps of claim 1 responsive to a change in a load on the gas turbine engine. 7. The method of claim 1, further comprising monitoring the dynamic operating condition of the first burner to determine when the first burner reaches its predetermined dynamic operating condition using the controller and a first burner dynamic condition sensor. 8. The method of claim 1, further comprising monitoring the first mass flow rate using the controller and flow sensor to identify when the first mass flow rate is not being maintained at the maintenance level. 9. The method of claim 8, further comprising correcting a first mass flow rate being identified as not being maintained to the maintenance level using the controller and at least one of the stage fuel flow valve and the first burner flow valve. 10. In a gas turbine combustor comprising at least two stages, a first stage having a plurality of burners and having a dynamic response characteristic being more sensitive to an amount of a fuel flow than a dynamic response characteristic of a second stage, a method for controlling combustion in the combustor comprising: monitoring dynamic operating conditions for each of the burners in the first stage of burners of a gas turbine using a dynamic condition sensor; reducing an overall fuel flow provided to the first stage while sequentially reaching respective predetermined dynamic operating conditions of each of the burners of the first stage using a controller to control a stage flow valve, wherein respective predetermined operating conditions exhibit a predetermined degree of dynamic instability; and maintaining respective burner fuel mass flow rates delivered to the respective burners at respective maintenance levels once the respective predetermined operating condition of the respective burner is reached so that the predetermined dynamic operating conditions of each burner is maintained using respective burner flow sensors and respective burner flow valves, while continuing to reduce the overall fuel flow using the controller and stage flow valve. 11. The method of claim 10, wherein monitoring dynamic operating conditions of burners further comprises monitoring the dynamic operating conditions of each of the burners using a burner dynamic condition sensor for each burner to determine when each burner reaches its predetermined dynamic operating condition. 12. The method of claim 10, further comprising monitoring the respective burner fuel flow rates to identify when a burner fuel flow rate is not being maintained at the maintenance level using the controller and respective burner flow sensor. 13. The method of claim 12, further comprising correcting a burner fuel flow rate being identified as not being maintained to return the burner fuel flow rate to the maintenance level using the controller, the respective burner flow sensor, and at least one of the stage fuel flow valve and the respective burner flow valve. 14. The method of claim 10, further comprising maintaining the overall fuel flow after reaching the predetermined dynamic operating conditions of each of the burners of the first stage using the controller and the stage flow valve. 15. The method of claim 10, further comprising, when the predetermined dynamic operating condition for each burner is reached, increasing the respective burner fuel flow rate to provide a desired operating margin away from the predetermined dynamic operating condition using the controller, respective burner flow sensors, and at least one of the stage fuel flow valve and the respective burner flow valve. 16. The method of claim 10, further comprising performing the steps of claim 13 responsive to a change in a load on the gas turbine engine. 17. The method of claim 10, wherein the first stage comprises a pilot premix stage.