Patent ID: 8408233
Filing Date: 2013-04-02
Classification: F02C,Y10T

Abstract:
1. A fuel flow system for a gas turbine engine, the system comprising: a first pump connected to a nozzle; a second pump connected to the nozzle and arranged in parallel with the first pump; a metering valve disposed downstream from the first pump and upstream from the nozzle: an actuator disposed downstream from the first pump and upstream from the metering valve, the actuator receiving a high pressure fluid from the first pump and returning a low pressure fluid upstream to inlets of the first pump and the second pump; a bypass loop that recycles fuel flow from the first pump and the second pump to the inlets of the first pump and second pump; an integrating bypass valve having a first window that regulates fuel from the first pump through the bypass loop and a second window that regulates fuel from the second pump through the bypass loop; and a pilot valve that senses a pressure drop across the metering valve and in response either directs a portion of the high pressure fluid upstream from the actuator or directs a portion of the low pressure fluid downstream from the actuator to the integrating bypass valve to control a size of the first window and a size of the second window of the integrating bypass valve.