An aircraft air conditioning system comprising an ambient air line, for ambient air to flow through, connected to supply ambient air to a mixer of the aircraft air conditioning system. An ambient air compressor is arranged in the ambient air line for compressing the ambient air flowing there through. A refrigerating apparatus comprises a refrigerant circuit for a refrigerant to flow through, including a refrigerant compressor arranged in the refrigerant circuit. The refrigerant circuit is coupled thermally to the ambient air line to transfer heat from the ambient air to the refrigerant before the ambient air is supplied to the mixer. A cabin exhaust air turbine is connected to a cabin exhaust air line, is coupled to the ambient air compressor arranged in the ambient air line, and is configured to expand the cabin exhaust air flowing through the cabin exhaust air line and to drive the ambient air compressor.

An air cycle machine is provided. The air cycle machine can be included an environmental control system of an aircraft. The air cycle machine can include a turbine comprising a plurality of inlet gas flow paths, a compressor driven by the turbine from a shaft, and a fan driven by the turbine from the shaft.

An airplane is provided. The airplane includes a pressurized medium, a turbine, and a valve. The turbine includes at least one nozzle. The valve is located upstream of the turbine. The valve provides the pressurized medium to the at least one nozzle of the turbine according to an operational mode.

An air cycle machine includes a compressor in fluid communication with a load cooling heat exchanger, a first valve and a first turbine connecting the compressor to the load cooling heat exchanger, and a second valve and a second turbine. The second valve and the second turbine connect the compressor to the load cooling heat exchanger and connected in parallel with the first valve and the first turbine between the compressor and the load cooling heat exchanger. Air cycle machine systems and methods of controlling air flow through air cycle machines are also described.

A duct is provided and includes a tubular member having an inlet portion, an outlet portion and a central portion interposed between the inlet and outlet portions and a tributary tubular member fluidly coupled to the tubular member at the central portion. The tributary tubular member includes first and second torus sectors defining first and second apertures, respectively, through which an upstream end of the central portion extends. The second torus sector is disposed within the first torus sector to define a sectioned toroidal annulus about the first and second apertures and between an exterior surface of the second torus sector and an interior surface of the first torus sector.

A method of operating an environmental control system of an aircraft includes providing a first medium to the environmental control system including a compressor and a turbine. The first medium is provided to the compressor and the turbine sequentially. A second medium is provided to the environmental control system. In a first mode of operation, the first medium and the second medium mix within the turbine and in a second mode of operation the second medium bypasses the turbine such that the first medium and the second medium mix downstream from the turbine.

An environmental control system of a vehicle includes a first compression device including a compressor, a first turbine, and a power turbine operably coupled by a shaft. The first turbine is configured to receive a first medium, the compressor is configured to receive a second medium, and the power turbine is configured to receive a third medium. A second compression device, separate from the first compression device, includes a second turbine. The environmental control system is operable in a first mode and a second mode. In the first mode, the second medium is provided to the compressor and the second turbine sequentially. In the second mode, the second medium bypasses the second turbine. In in both the first mode and the second mode, only the second medium is provided to an outlet of the environmental control system.

An environmental control system (ECS) for an aircraft includes a primary heat exchanger, a compressor including an inlet fluidically connected to the primary heat exchanger, a turbine operatively connected to the compressor, and a cryogenic fluid heat exchanger fluidically connected to the primary heat exchanger.

A cabin blower system, for an aircraft, comprising: a cabin blower compressor, for compressing air for delivery to a cabin of an aircraft, comprising a compressor drive shaft running on a contactless bearing system; and a transmission comprising an input and an output, the input being arranged to receive power from an engine of the aircraft and the output being arranged to mechanically drive the cabin blower compressor, wherein the output of the transmission is mechanically coupled with the compressor drive shaft via a flexible drive coupling.

An environmental control system of a vehicle includes a ram air circuit including a ram air shell having a ram air heat exchanger positioned therein, a dehumidification system arranged in fluid communication with the ram air circuit, a first compression device arranged in fluid communication with the dehumidification system, the first compression device including a first compressor, and a second compression device arranged in fluid communication with the ram air circuit. The second compression device includes a second compressor. A first medium is provided to the first compressor and to the second compressor in series.