Combined pressure regulating and fuel flow system

摘要

A fuel delivery system for providing a desired fuel flow to an engine includes a pump means for providing fuel to a metering valve which in turn regulates the flow of fuel to provide a desired fuel flow to the engine by varying the area of the metering window. The pressure differential across the metering valve is maintained at a desired set point in order to precisely control desired fuel flow by varying the area of the metering window. The pressure differential is sensed by a pressure regulating motive flow control valve (PRMFV). The PRMFV is positioned in response to the pressure differential to bypass fuel away from the metering valve to control the differential pressure to the desired set point. The PRMFV first bypasses fuel to an ejector pump and as the amount of excess flow to the metering valve increases the PRMFV bypasses fuel back to the inlet of the pump means.