Pressure atomizing fuel injection assembly

摘要

A pressure atomizing fuel nozzle assembly for a gas turbine engine includes a support housing in which a pressure-responsive fuel check valve and metering valve are disposed in line to provide a flow of primary fuel for engine start-up and low power operation and secondary fuel for higher power operation. The check valve is located upstream between the fuel inlet and a sleeve inside of which the metering valve is disposed. The check valve prevents the fuel manifold from draining after engine shut-down and controls fuel entry to both the secondary fuel chamber within the sleeve and to an annular primary fuel chamber between the sleeve and support housing connected in fuel flow relation to the secondary chamber by a fuel filter. The primary fuel flows through the primary chamber around the exterior of the secondary chamber and through an annular primary fuel conduit disposed around the secondary fuel conduit in the housing strut to the nozzle attached to the strut. The secondary fuel flow is controlled by the downstream metering valve in the sleeve and flows interiorly of the primary fuel to the nozzle. In this way, the secondary fuel flow path is subjected to a cooling action by the primary fuel as it flows to the nozzle. The check valve is configured to provide a high closing force and to cause the secondary fuel to exert a washing action on the fuel filter incorporated into the sleeve under high power engine operation conditions.