An energy harvesting system is provided and a corresponding method for harvesting energy from an aircraft cabin pressurization system utilizing the same. According to one aspect, an energy harvesting system includes an aircraft cabin enclosing a high-pressure environment of pressurized air. An air input receives incoming air from a low-pressure environment and an air output expels outgoing air from the high-pressure environment. A turbine receives the pressurized air expelled from the aircraft cabin and utilizes the pressurized air to produce rotational motion on a turbine shaft. An energy harvesting mechanism is coupled to the turbine shaft and utilizes the rotational motion from the turbine shaft to compress the incoming air or to create electrical energy.

A dual-use air turbine system for a gas turbine engine of an aircraft is provided. The dual-use air turbine system includes a variable area air turbine mechanically linked to a spool of the gas turbine engine through a multi-speed gear set. The dual-use air turbine system also includes a plurality of valves in pneumatic ducting operable to direct an engine start air flow through an inlet of the variable area air turbine and drive rotation of the spool during an engine start mode of operation. The valves are further operable to direct an engine bleed air flow from a compressor section of the gas turbine engine through the inlet of the variable area air turbine and drive rotation of the spool during an environmental control system active mode of operation.

An aircraft environmental control system comprising a bleed air or compressed ambient air input and a RAM air input, heat exchanger means for receiving bleed air from the bleed air input and RAM air from the RAM air input and using RAM air to cool the bleed air, and means for providing the cooled bleed air to an interior of the aircraft; the system further comprising means for feeding back exhaust air emitted from the interior of the aircraft to combine with the RAM air to further cool the bleed air or compressed ambient air.

A system is provided. The system includes an air conditioning pack; a first medium; a second medium; a first mixing point located outside the air conditioning pack and configured to mix the first medium with the second medium; and a second mixing point located inside the air conditioning pack and configured to mix the first medium with the second medium.

A system is provided. The system includes a first inlet providing a medium from a source, a compressing device in communication with the first inlet, and at least one heat exchanger. The compressing device includes a compressor that receives the medium, a first turbine downstream of the compressor, and a second turbine that receives the medium. An outlet of the at least one heat exchanger is in fluid communication with an inlet of the compressor and an inlet of the first turbine.

A system is provided. The system includes an inlet providing a first medium; a compressing device comprising a compressor, and at least one heat exchanger located downstream of the compressor. The compressing device is in communication with the inlet providing the first medium. The at least one heat exchanger includes a first pass and a second pass. An outlet of the first pass of the at least one heat exchanger is in fluid communication with an inlet of the compressor.

A system for an aircraft is provided. The system includes a compressing device and at least one heat exchanger. The compressing device includes a compressor, a turbine downstream of the compressor, and an electric motor coupled to the turbine and the compressor. Further, the compressor includes a high rotor backsweep. The system can be an air conditioning system.

A system is provided. The system includes an inlet providing a first medium; an inlet providing a second medium; a compressing device including a compressor and a turbine; a motor operating on an input power that is less than or equal to 0.5 kilowatts per pound per minute of the first medium compressed; and at least one heat exchanger located downstream of the compressor. The compressing device is in communication with the inlet providing the first medium. The turbine is downstream of the compressor. An outlet of the at least one heat exchanger is in fluid communication with an inlet of the compressor and an inlet of the turbine.

An airplane is provided. The airplane includes a pack. The pack includes a shaft, a compressor, and a turbine coupled to the compressor via the shaft. The turbine receives and expands a first medium to provide power to the compressor via the shaft. The compressor receives and compresses a second medium in accordance with the power provided by the turbine via the shaft. The turbine is fluidly coupled to a heat exchanger of an air conditioning system.

A system and method that comprises an air cycle machine, a flow of bleed air, at least one heat exchanger, and an inlet configured to supply the flow of the bleed air is provided. The bleed air directly flows from a source to either a compressor of the air cycle machine or the at least one heat exchanger in accordance with a high pressure, low pressure, or pressure boost operation mode. The system and method also can also utilize recirculated air flowing from the chamber to drive or maintain the air cycle machine in accordance with the above modes.