An airplane is provided. The airplane includes a pressurized volume and an air conditioning system. The pressurized volume provides a first medium. The air conditioning system includes a heat exchanger and a compressor. The heat exchanger transfers heat from a second medium to the first medium. The compressor receives the second medium. The compressor is upstream of the heat exchanger in a flow path of the second medium.

A compressor temperature control system and method for an aircraft air cycle machine is presented. The system prevents overheating of the compressor using a low limit valve positioned between a turbine outlet and a bleed air source. The low limit valve directs the air to an air cycle machine, or bypasses the machine, in regards at least in part to the air temperature measured in the cabin supply duct.

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 environmental control system (ECS) for an aircraft includes a primary heat exchanger configured to receive bleed air from a turbine compressor of the aircraft and a secondary heat exchanger having an input configured to receive a flow from the primary heat exchanger and a secondary heat exchanger output. The ECS also includes a thermoelectric condensing device having an input in fluid communication with the output of the secondary heat exchanger and also having a thermoelectric condensing device output.

An aircraft air conditioning system comprising an ambient air supply line with a first end connected to an ambient air inlet and a second end connected to a mixing chamber. A first electrically driven ambient air compressor in the ambient air supply line compresses the ambient air flowing therethrough. A first ambient air branch line branches off from the ambient air supply line upstream of the first ambient air compressor and rejoins the supply line downstream of the air compressor. A second ambient air compressor in the first ambient air branch line compresses the ambient air flowing therethrough. A cabin exhaust air line has a first end connected to an air conditioned aircraft area. A cabin exhaust air turbine in the exhaust air line is driven by the exhaust air flowing through the cabin exhaust air line and is coupled to drive the second ambient air compressor.

An environmental control system of an aircraft includes a plurality of inlets for receiving a plurality of mediums including a first medium and a second medium and an outlet for delivering a conditioned flow of the second medium to one or more loads of the aircraft. A ram air circuit includes a ram air shell having at least one heat exchanger positioned therein. A compressing device is arranged in fluid communication with the ram air circuit and the outlet. The compressing device including a first compressor, a second compressor, and at least one turbine operably coupled via a shaft. The first compressor and the second compressor are arranged in parallel with respect to a flow of the second medium and the first medium is used as a heat sink by another component within the environmental control system.

A compressing device for use in an environmental control system includes at least one turbine configured to provide energy by expanding one or more mediums. The one or more mediums provided at an outlet of the at least one turbine form a heat sink within the environmental control system. A compressor is configured to receive energy from the one or more mediums expanded across the at least one turbine. During a first mode of the compressing device, energy derived from a first medium and a second medium of the one or more mediums is used to compress a second medium at the compressor. During a second mode of the compressing device, energy derived from the first medium, the second medium, and a third medium of the one or more mediums is used to compress the second medium at the compressor.

An air cycle machine for an environmental control system for an aircraft includes at least one turbine configured to receive and extract work from a first medium and a third medium. A compressor is configured to compress a second medium and a shaft mechanically couples the at least one turbine and the compressor. A mixing point is located downstream of at least one turbine. A mixture of the first medium and the third medium generated at the mixing point is provided to another component of the environmental control system.

An air cycle machine includes a housing having an exterior wall and an interior wall, a scavenging turbine supported for rotation within the housing, and an ambient air fan. The ambient air fan is supported for rotation within the housing and is operably associated with the scavenging turbine. The interior wall defines therethrough a turbine-fan port that fluidly couples the ambient air fan to the scavenging turbine for communication of an overboard air flow to an ambient air flow without external ducting. Environmental control systems and methods of flowing fluid through air cycle machines are also described.