A thermal management system includes at least one vapor compression system (VCS) that is configured to cool portions of the vehicle. The VCS circulates a fluid therethrough to cool the portions of the vehicle through heat exchange. At least one reverse air cycle machine (RACM) couples to VCS through a first heat exchanger. The RACM is configured to receive ram air. The RACM expands the ram air. Heat from the fluid circulating through the VCS is transferred to the expanded ram air through the first heat exchanger.

Example implementations for maintaining airflow into a flight deck of an aircraft are described herein. An example method may involve detecting, at a computing system and using a flow sensor, a decrease in a level of airflow entering into the flight deck such that the level of airflow is below a threshold level. The aircraft may include air sources configured to direct airflow towards occupancy areas (e.g., the cabin and flight deck) of the aircraft. The method may further involve adjusting a control valve to cause an increase in the level of airflow entering into the flight deck based on detecting the decrease in level of airflow entering into the flight deck. The control valve may be configured to enable and disable airflow from entering into the flight deck.

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.

A thermal management system for an aircraft is provided. The thermal management system may comprise a first vapor compression circuit, a second vapor compression circuit, and an intercooler. The first vapor compression circuit may define a first flowpath for fluid compression, condensation, expansion, and evaporation. The second vapor compression circuit may define a second flowpath for fluid compression, condensation, expansion, and evaporation. The intercooler may be disposed in cascading thermal communication between the first vapor compression circuit and the second vapor compression circuit. Generally, heat generated by the aircraft may be transferred to the first vapor compression circuit during aircraft operation.

A cooling system for an aircraft includes a first cooling circuit having a first evaporator and a second evaporator, and a second cooling circuit having a third evaporator and a fourth evaporator. One of the first and second cooling circuits includes a first set of valves arranged to direct refrigerant through a first cooling sub-circuit, a second cooling sub-circuit, or both the first and second cooling sub-circuits based on ambient conditions. Two of the evaporators are installed on a first side of the aircraft, and the other two of the four evaporators are installed on a second side of the aircraft opposite the first side, and the first and second cooling circuits reject heat, via a heat exchanger, from their respective cooling circuit to air passing into an engine of the aircraft.

An aircraft humidifier is engineered as a stand-alone, fully integrated aircraft humidifier that is suitable for providing uniform, non-wetting humidified air disbursed by the aircraft humidifier into ambient air to increase the relative humidity in low humidity environments such as aircraft interiors, including cockpits, cabins, crew rests, cargo holds, and lavatories as well as any other enclosed areas.

Environmental control system for aircraft are provided having a ram module having a primary heat exchanger and a secondary heat exchanger, a refrigeration module having an air cycle machine module and a condenser heat exchanger module, and at least one conduit fluidly connecting the ram module to the refrigeration module such that the ram module and the refrigeration module can be installed in two separate volumes of the aircraft.

Bleed air systems for use with aircraft and related methods are disclosed. An example apparatus includes a compressor having a compressor inlet, a compressor outlet, and a first drive shaft. The compressor outlet is to be fluidly coupled to a system of an aircraft that receives pressurized air, and the compressor inlet is to receive bleed air from a low-pressure compressor of an engine of the aircraft. The example apparatus includes a gearbox operatively coupled to the first drive shaft to drive the compressor. The gearbox is to be operatively coupled to and powered by a second drive shaft extending from the engine. The example apparatus also includes a clutch disposed between the first drive shaft and the gearbox to selectively disconnect the first drive shaft from the gearbox.