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.

A system and method for improved system efficiency of an integrated power and control unit (IPCU) of an aircraft is disclosed. The system uses an open-loop cooling system and turbo machine power matching to provide wide operation range without over-sizing. In order to reduce the temperature of the air flow through the cooling heat exchanger, the cooling turbine need to expand further in the same time generating power but the power could be higher than the compressor could absorb so a generator that would convert the power and used in supplying the aircraft would result in more efficient system.

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 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.

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 and a turbine downstream of the compressor. The system is powered by mechanical power from the medium and by electrical power through a motor. The motor input power is less than or equal to 0.5 kilowatt per pounds per minute of the medium compressed.

A method of operating a gas turbine engine compressor. The method includes: determining an operating point of the compressor, and modulating mass flow of environmental control system input air to maintain the operating point of the gas turbine engine compressor within predetermined limits.

A method of monitoring a heat exchanger arrangement is provided. The method includes detecting a rotational speed of a ram air fan configured to draw air through the heat exchanger arrangement. The method also includes detecting a power input from a motor to the ram air fan to maintain a commanded rotational speed of the ram air fan. The method further includes comparing the power input detected to a predetermined power limit for the commanded rotational speed. The method yet further includes decreasing the rotational speed of the ram air fan with a controller if the power input detected exceeds the predetermined power limit.

Aircraft turboprop engine (110), comprising at least one low-pressure body (12) and one high-pressure body (14), the low-pressure body driving a thrust propeller by means of a gearbox (16), the turboprop engine further comprising means for supplying air to an air-conditioning circuit (36) of an aircraft cabin, said supply means comprising a load compressor (60), a rotor (61) of which is coupled to said low-pressure body by means of said gearbox, characterised in that said supply means further comprise means for controlling the rotation speed of the rotor (61) of said compressor (60), which means comprise an electric motor (70), and a mechanical differential (72) for coupling a first output shaft (74) of said electric motor to a second output shaft (76) of said gearbox and to said compressor rotor (61), such that the rotation speed (V3) of said rotor depends on the respective rotation speeds (V1, V2) of said first and second output shafts.

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.