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US 11,530,651 B2Granted
Staged combustion
AssigneeROLLS-ROYCE plc
InventorsChristopher P. Madden, Peter Swann
Life of this patent
Estimating the term…
Abstract
A gas turbine engine for an aircraft. The gas turbine comprises a staged combustion system having pilot injectors and main injectors, a fuel metering system configured to control fuel flow to the pilot injectors and the main injectors, and a fuel system controller. The controller is configured to identify an atmospheric condition, determine a ratio of pilot fuel flow rate for the pilot injectors to main fuel flow rate for the main injectors in response to the atmospheric condition, and inject fuel by the pilot injectors and the main injectors in accordance with said ratio to control an index of soot emissions caused by combustion of fuel therein.
Claims15
A method of operating a staged combustion system in an aircraft gas turbine engine, comprising:
- providing pilot injectors for rich combustion and main injectors for lean combustion in said staged combustion system;
- identifying an atmospheric condition;
- determining a ratio of pilot fuel flow rate for the pilot injectors to main fuel flow rate for the main injectors in response to the atmospheric condition;
- wherein the determining step comprises:
- identifying the atmospheric condition to the effect that a model indicates that reducing an optical depth of a condensation trail produced by the engine would reduce a net warming impact of the condensation trail;
- evaluating the ratio of pilot fuel flow rate to main fuel flow rate that varies soot production to reduce ice particle formation;
- wherein the evaluating step comprises:
- obtaining a measurement of an ambient temperature from a temperature sensor;
- in response to the ambient temperature being greater than a transition temperature, evaluating the ratio of pilot fuel flow rate to main fuel flow rate that decreases an index of soot emissions;
- in response to the ambient temperature being less than or equal to the transition temperature and a current index of soot emissions being less than a transition value, evaluating the ratio of pilot fuel flow rate to main fuel flow rate that increases the index of soot emissions;
- in response to the ambient temperature being less than or equal to the transition temperature and the current index of soot emissions being greater than the transition value, evaluating the ratio of pilot fuel flow rate to main fuel flow rate that decreases the index of soot emissions;
- and
- injecting fuel by the pilot injectors and the main injectors in accordance with said ratio to control the index of soot emissions caused by combustion of fuel therein.
10 more elements
A gas turbine engine for an aircraft, comprising:
- a staged combustion system having pilot injectors and main injectors;
- a fuel metering system configured to control fuel flow to the pilot injectors and the main injectors;
- a fuel system controller configured to:
- identify an atmospheric condition;
- determine a ratio of pilot fuel flow rate for the pilot injectors to main fuel flow rate for the main injectors in response to the atmospheric condition;
- and
- wherein the fuel system controller is configured to determine the ratio of pilot fuel flow rate to main fuel flow rate by:
- identifying the atmospheric condition to the effect that reducing an optical depth of the condensation trail would reduce a net warming impact of the condensation trail;
- evaluating the ratio of pilot fuel flow rate to main fuel flow rate that varies soot production to reduce ice particle formation;
- wherein the evaluating step comprises:
- obtaining a measurement of an ambient temperature from a temperature sensor;
- in response to the ambient temperature being greater than or equal to a transition temperature, evaluating the ratio of pilot fuel flow rate to main fuel flow rate that decreases an index of soot emissions;
- in response to the ambient temperature being less than or equal to the transition temperature and a current index of soot emissions being less than a transition value, evaluating the ratio of pilot fuel flow rate to main fuel flow rate that increases the index of soot emissions;
- in response to the ambient temperature being less than or equal to the transition temperature and the current index of soot emissions being greater than the transition value, evaluating the ratio of pilot fuel flow rate to main fuel flow rate that decreases soot production;
- and
- inject fuel by the pilot injectors and the main injectors in accordance with said ratio to control the index of soot emissions caused by combustion of the fuel therein.
13 more elements
A gas turbine engine for an aircraft, comprising:
- a staged combustion system having pilot injectors and main injectors;
- a fuel metering system configured to control fuel flow to the pilot injectors and the main injectors;
- a fuel system controller configured to:
- identify an atmospheric condition;
- determine a ratio of pilot fuel flow rate for the pilot injectors to main fuel flow rate for the main injectors in response to the atmospheric condition;
- and
- wherein the fuel system controller is configured to determine the ratio of pilot fuel flow rate to main fuel flow rate by:
- identifying the atmospheric condition to the effect that increasing an optical depth of the condensation trail would reduce a net warming impact of the condensation trail;
- evaluating the ratio of pilot fuel flow rate to main fuel flow rate that varies soot production to increase ice particle formation;
- wherein the evaluating step comprises:
- obtaining a measurement of an ambient temperature from a temperature sensor;
- in response to the ambient temperature being greater than a transition temperature, evaluating the ratio of pilot fuel flow rate to main fuel flow rate that increases an index of soot emissions;
- in response to the ambient temperature being less than or equal to the transition temperature and a current index of soot emissions being greater than a transition value, evaluating the ratio of pilot fuel flow rate to main fuel flow rate that increases the index of soot emissions;
- in response to the ambient temperature being less than or equal to the transition temperature and the current index of soot emissions being less than or equal to the transition value, evaluating the ratio of pilot fuel flow rate to main fuel flow rate that decreases the index of soot production;
- and
- inject fuel by the pilot injectors and the main injectors in accordance with said ratio to control the index of soot emissions caused by combustion of fuel therein.
13 more elements
Dependencies are inferred from the claim text.