Fuel control system for a gas turbine engine
AssigneeROLLS-ROYCE plc
InventorHugh F. Cantwell
Life of this patent
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Abstract
A gas turbine engine fuel system of the type using the rotational speed of the high pressure spool as the main control parameter has a trimmer device which reduces the effect of variation of engine geometry in cold starts etc. The trimmer uses the throttle lever angle and engine inlet pressure to compute the desired value of a thrust-related parameter such as weighted mean exhaust pressure, this desired value being compared with the actual value to produce a trim input to the main fuel control unit.
Claims10
A fuel system for a gas turbine engine of the type having a high pressure spool, means for producing signals proportional to the rotational speed of the high pressure spool, engine inlet pressure and at least one other parameter uniquely related to the thrust produced by the engine, a thottle lever for selecting a desired value of engine thrust and a main fuel control unit for adjusting the fuel flow to the engine in accordance with the throttle lever angle and the measured rotational speed of the high pressure spool so as approximately to produce the desired thrust, and a trimmer for determining from the throttle lever angle and said engine inlet pressure the desired value of said other parameter, comparing the computed value with the measured value, and applying a trimming input to the main fuel control unit to trim this unit in accordance with the input to provide a fuel flow to the engine which causes the engine to produce the desired engine thrust.
Dependencies are inferred from the claim text.