An environmental control system of an aircraft includes a ram air circuit including a ram air shell having at least one heat exchanger positioned therein, a dehumidification system arranged in fluid communication with the ram air circuit, and a compression device arranged in fluid communication with the ram air circuit and the dehumidification system. The compression device includes a compressor, a turbine, and a fan coupled by a shaft, wherein the fan is operable to move ram air through the ram air circuit and the turbine includes a first inlet for receiving a first flow of medium and a second inlet for receiving a second flow of medium.

A compressing device for use in an environmental control system includes at least one turbine configured to provide energy by expanding one or more medium. 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 of the one or more mediums is used to compress a second medium at the compressor and during a second mode of the compressing device, energy derived from both the first medium and a third medium of the one or more mediums is used to compress a second medium at the compressor.

Efficient energy storage is provided by using a working fluid flowing in a closed cycle including a ganged compressor and turbine, and capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. This system can operate as a heat engine by transferring heat from the hot side to the cold side to mechanically drive the turbine. The system can also operate as a refrigerator by mechanically driving the compressor to transfer heat from the cold side to the hot side. Heat exchange between the working fluid of the system and the heat storage fluids occurs in counter-flow heat exchangers. In a preferred approach, molten salt is the hot side heat storage fluid and water is the cold side heat storage fluid.

A sensor assembly includes a navigation sensor. The sensor assembly includes a heatsink thermally coupled to the navigation sensor. The sensor assembly includes an air conditioning unit. The sensor assembly includes a duct positioned to direct airflow from the air conditioning unit toward the heatsink.

Efficient energy storage is provided by using a working fluid flowing in a closed cycle including a ganged compressor and turbine, and capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. This system can operate as a heat engine by transferring heat from the hot side to the cold side to mechanically drive the turbine. The system can also operate as a refrigerator by mechanically driving the compressor to transfer heat from the cold side to the hot side. Heat exchange between the working fluid of the system and the heat storage fluids occurs in counter-flow heat exchangers. In a preferred approach, molten salt is the hot side heat storage fluid and water is the cold side heat storage fluid.

An air cycle machine includes a housing, a scavenging turbine, and an ambient air fan. The housing has an exterior wall defining an overboard air inlet, an ambient air inlet, and an ambient air outlet. The scavenging turbine is arranged within the housing, is supported for rotation about a rotation axis, and is in fluid communication with the overboard air inlet. The ambient air fan is arranged within the housing, is supported for rotation about the rotation axis within the housing, and has a radially inner spoked portion and radially outer bladed portion. The bladed portion of the ambient air fan fluidly couples the ambient air inlet to the ambient air outlet and the spoked portion of the ambient air fan fluidly couples the scavenging turbine to the ambient air fan within the housing. Environmental control systems and fluid communication methods are also described.

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.

A system includes a first fluid flow path configured to condition a pressurized medium and deliver the pressurized medium to one or more loads. The first fluid flow path including an air cycle machine. A second fluid flow path is configured to circulate a working fluid. The second fluid flow path includes a heat exchanger thermally coupled to the first fluid flow path. Within the heat exchanger, heat extracted from the pressurized medium is transferred to the working fluid. The second fluid flow path additionally includes a turbine operably coupled to the air cycle machine, a condenser, and a pump operable to circulate the working fluid through at least a portion of the second fluid flow path. The turbine is rotationally driven by expanding the working fluid across the turbine.

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.

An air cycle machine includes a compressor in fluid communication with an output conduit, a first turbine operably connected to the compressor and fluidly coupling the compressor with the output conduit, a second turbine operably connected to the compressor and fluidly coupling the compressor with the output conduit, and a valve. The valve couples the compressor with the output conduit and has an open position and a closed position. In the open position the first turbine and the second turbine are fluidly connected in parallel between the compressor and the output conduit. In the closed position the first turbine is fluidly connected in series with the second turbine between the compressor and the output conduit. Air cycle machine systems and methods of controlling flow in air cycle machines are also described.