Patent ID: 8727270
Filing Date: 2014-05-20
Classification: B64D,F02C,F05D,Y02T

Abstract:
1. A propulsion system for an aircraft, comprising: a gas turbine engine having at least a high pressure (HP) spool and a low pressure (LP) spool, wherein the LP spool is operative to drive a propulsor; and a hybrid auxiliary power unit (APU) mechanically coupled to both the HP spool and the LP spool, wherein the hybrid APU includes an APU compressor; an APU turbine; and a fuel cell fluidly disposed between the APU compressor and the APU turbine, wherein the fuel cell is operative to receive as an oxidant air pressurized by the APU compressor; to generate electrical power using a fuel and the oxidant; to heat the air pressurized by the APU compressor; and to discharge the heated pressurized air into the APU turbine, wherein the hybrid APU is operative to supply rotational power to both the HP spool and the LP spool at the same time.