Abstract: Combined aircraft hybrid fuel cell auxiliary power unit and environmental control system and methods are disclosed. In one embodiment, an auxiliary power unit includes a fuel cell component which chemically converts combustible fuel into electrical energy. Unutizlied fuel emitted by the fuel cell component is combusted by a burner to generate heated gas. The heated gas is received by and drives a turbine, which in turn drives a drive shaft. A compressor, coupled to the drive shaft, compresses a source of oxidizing gas for supplying compressed oxidizing gas to the fuel cell component and to an environmental control system. A heat exchanger controls the temperature of the pressurized air leaving the environmental control system to provide the cabin air supply. Finally, a generator is coupled to the drive shaft to be driven by the turbines to generate additional electrical energy.

Abstract: An apparatus and method for improving the efficiency and energy output of a power unit are disclosed. The power unit employs a fuel cell configured to chemically convert combustible fuel into electrical energy. A waste fuel burner is configured to receive uncombusted fuel emitted by the fuel cell, and the waste burner combusts the uncombusted fuel to generate heated gas. A turbine is configured to receive and be driven by the heated gas. The turbine is further configured to drive a drive shaft which is coupled to a compressor. The compressor is configured to compress a pressurized source of oxidizing gas for supplying compressed oxidizing gas to the fuel cell such that efficiency of the fuel cell is improved. A generator also may be coupled to the drive shaft, and the generator is configured to generate electrical power from the drive shaft being turned by the turbine.

Abstract: An apparatus and method for improving the efficiency and energy output of a power unit are disclosed. The power unit employs a fuel cell configured to chemically convert combustible fuel into electrical energy. A waste fuel burner is configured to receive uncombusted fuel emitted by the fuel cell, and the waste burner combusts the uncombusted fuel to generate heated gas. A turbine is configured to receive and be driven by the heated gas. The turbine is further configured to drive a drive shaft which is coupled to a compressor. The compressor is configured to compress a pressurized source of oxidizing gas for supplying compressed oxidizing gas to the fuel cell such that efficiency of the fuel cell is improved. A generator also may be coupled to the drive shaft, and the generator is configured to generate electrical power from the drive shaft being turned by the turbine.