Fuel/air supply system for a fuel injector and methods of operation

Abstract

The fuel and air supply system of the present invention provides fuel from a fuel pump at a first pressure upstream of a pressure reducer, fuel being provided directly to the fuel injector at a reduced pressure on the downstream side of the pressure reducer. A bypass line in communication with the fuel line upstream of the pressure reducer provides fuel to an air reservoir at the first pressure. The air reservoir lies in communication with a porous member(s) in the fuel injector in an air inlet to a fuel volume within the injector upstream of the pressure reducer. Upon flow of fuel into the air reservoir and closure of normally open fuel and air valves in the reservoir, air at the first pressure is supplied the porous member(s), creating a pressure differential across the member(s), causing air to flow through the porous member(s) to form air bubbles in the fuel volume for two-phase flow through the fuel injector orifice. The air flows for a predetermined time until the reservoir fills with fuel which precludes further air flow into the injector. Upon shutdown of the engine, the valves in the air reservoir open, draining the fuel from the air reservoir and enabling air at atmospheric pressure to enter the reservoir, returning the system for reuse upon engine startup.