Controlling the fuel supply to a combustor of a gas turbine engine
AssigneeROLLS-ROYCE plc
InventorsNicholas C Pashley, Leslie R Summerfield
Life of this patent
Estimating the term…
Abstract
The minimum fuel flow to a combustor of a gas turbine engine is controlled in response to the combustor inlet temperature T3 in order to provide a FAR stability margin which responds to the combustor inlet temperature. This enables the FAR stability margin to be reduced when the risk of flame out is low, for example when the combustor entry temperature is high, while increasing the FAR stability ratio when the combustor entry temperature is low, ie when the engine is idling or when water is ingested.
Claims9
A method of controlling the fuel supply to a combustor of a gas turbine engine, the method comprising:
- (a) deriving from a first set of operating parameters of the engine, a first derived value which represents the fuel requirement of the combustor multiplied by a factor, which factor includes the combustor inlet temperature;
- (b) measuring the combustor inlet temperature and calculating therefrom the factor;
- (c) dividing the first derived value by the factor to generate a second derived value;
- and
- (d) generating the fuel requirement from the second derived value.
Apparatus for controlling the fuel supply to a combustor of a gas turbine engine, the control system comprising:
- (a) a processor unit adapted to derive, from a first set of operating parameters of the engine, a first derived value which represents the fuel requirement of the combustor multiplied by a factor, which factor includes the combustor inlet temperature;
- (b) a calculating device for receiving a signal representing the combustor inlet temperature, and for calculating the factor from the combustor inlet temperature;
- (c) a divider for dividing the first derived value by the factor to generate a second derived value;
- and
- (d) a calculating arrangement for generating the fuel requirement from the second derived value.
Dependencies are inferred from the claim text.