High efficiency, high pressure gas turbine engine fuel supply system and method

A gas turbine engine fuel supply system, comprising:

• a boost pump having a boost pump inlet and a boost pump outlet, the boost pump adapted to receive a drive torque and configured, upon receipt thereof, to draw fuel into the boost pump inlet and discharge the fuel from the boost pump outlet;
• a primary gear pump having a primary gear pump inlet and a primary gear pump outlet, the primary gear pump adapted to receive a drive torque and configured, upon receipt thereof, to draw fuel into the primary gear pump inlet and discharge the fuel from the primary gear pump outlet;
• a secondary gear pump having a secondary gear pump inlet and a secondary gear pump outlet, the secondary gear pump adapted to receive a drive torque and configured, upon receipt thereof, to draw fuel into the secondary gear pump inlet and discharge the fuel from the secondary gear pump outlet;
• a supercharger pump having a supercharger pump inlet and a supercharger pump outlet, the supercharger pump adapted to receive a drive torque and configured, upon receipt thereof, to draw fuel into the supercharger pump inlet and discharge the fuel from the supercharger pump outlet;
• a pump control pilot valve configured to supply a hydraulic control signal;
• and
• a pump control valve in fluid communication with the boost pump, primary gear pump, the secondary gear pump, and the supercharger pump, the pump control valve coupled to receive the hydraulic control signal and configured, in response thereto, to selectively move between a first position and a second position,
• wherein:
• in the first position, the pump control valve (i) fluidly isolates the supercharger pump from the boost pump, the primary gear pump, and the secondary gear pump and (ii) fluidly isolates the primary gear pump outlet from the secondary gear pump outlet,
• in the second position, the pump control valve fluidly communicates the supercharger pump inlet with the boost pump outlet, fluidly communicates the supercharger pump outlet with the primary gear pump inlet and the secondary gear pump inlet, and fluidly communicates the primary gear pump outlet and the secondary gear pump outlet.

A method of controlling the supply of fuel to a gas turbine engine, comprising the steps of:

• simultaneously supplying, from a fuel source, fuel to a first gear pump and a second gear pump;
• supplying a first portion of the fuel to the gas turbine engine via the first gear pump while simultaneously recirculating a second portion of the fuel through the second gear pump;
• and
• selectively supplying fuel to the gas turbine engine via the first and second gear pumps by:
• fluidly coupling the first and second gear pumps in parallel, and
• supplying fuel, from the fuel source, to the first and second gear pumps via a supercharger pump.