Engine fuel control system

摘要

An engine fuel control system includes a supply line delivering fuel to a fuel metering valve which controls the flow of fuel to burners of an engine. In use, the fuel is delivered at a first high pressure (HPa) to the supply line by a pump arrangement. The engine fuel control system further includes a restrictor located in the supply line. The restrictor is configured such that fuel exiting the restrictor for onward supply to the fuel metering valve is at a second high pressure (HP) which is lower than the first high pressure (HPa). The engine fuel control system further includes a pressure limiting valve which is actuated when the pressure difference (HPa-LP) between the first high pressure and the low pressure reaches a predetermined level to open a flow path for fuel on the supply line to bypass the restrictor, thereby limiting the pressure difference (HPa-LP).