Fuel control system for a gas turbine engine
AssigneeLucas Industries public limited company of Brueton House
InventorsBrian E. Sparks, Simon J. Burr
Life of this patent
Estimating the term…
Abstract
A gas turbine engine fuel control system includes a metering device responsive to an electrical signal for regulating fuel flow from a pump to the engine, a shut-off valve downstream of the metering device and operable by a first servo pressure, a spill valve operable by a second servo pressure for spilling fuel from upstream of the metering device, an electrically operable valve for controlling the first and second servo pressures, and a circuit for supplying electrical signals to the metering device and the electrically operable valve so that during shut down of the system the spill valve and the shut off valve are maintained respectively open and shut before the metering device shuts.
Claims15
A fuel control system for a gas turbine engine, comprising a pump, a metering device responsive to an electric control signal for regulating fuel flow from the pump to the engine, a shut-off valve downstream of said metering device and operable by a first servo pressure, a spill valve for spilling fuel from upstream of said metering device, said spill valve being operable by a second servo pressure, an electrically operable valve for controlling said first and second servo pressures, and a circuit for supplying electric signals to said metering device and said electrically operable valve so that during a first stage of shut-down of the system said shut-off valve is shut and said metering device is at least partially open and during a second stage of shut-down of the system said metering device is shut.
A fuel control system for a gas turbine engine, comprising a pump, a metering device for regulating fuel flow from the pump to the engine, a servo pressure operable shut-off valve downstream of said metering device, a spill valve responsive to the pressures upstream and downstream of said metering device, for spilling fuel from upstream of said metering device to maintain a pressure difference thereacross substantially constant, a line through which fuel can flow from the downstream side of said metering device to the inlet of said pump, a control valve and a first flow restrictor in series in said line between said downstream side and the pump inlet, the servo pressure for said shut-off valve being taken from between said control valve and said first restrictor, a second flow restrictor between said downstream side and said control valve, the flow resistances of said restrictors being such that, with said metering device and said shut-off valve shut, a leakage flow through said metering device will be such as to prevent an unacceptable temperature rise in fuel temperature.
A fuel control system for a gas turbine engine, comprising a pump, a metering device responsive to an electric control signal for regulating fuel flow from the pump to the engine, a shut-off valve downstream of said metering device and operable by a first servo pressure, a spill valve for spilling fuel from upstream of said metering device, said spill valve being operable by a second servo pressure, an electrically operable valve for controlling said first and second servo pressures, first and second flow restrictors connected in series with said electrically operable valve between the downstream side of said metering device and the inlet of said pump, said first servo pressure being derived from that between said electrically operable valve and said first flow restrictor, and a circuit for supplying electric signals to said metering device and said electrically operable valve so that during shut-down of the system said spill valve and shut-off valve are respectfully open and shut before said metering device shuts.
Dependencies are inferred from the claim text.