A Multi-Mode Regenerative Fuel Cell system comprising a non-flow thru fuel cell operatively coupled to a high or medium pressure electrolyzer; a distributed reactant storage assembly comprising at least one hydrogen storage means and at least one oxygen storage means, said distributed reactant storage assembly operatively coupled to said fuel cell and electrolyzer; a pilot oxygen storage means operatively coupled to said oxygen storage means; a water storage means operatively coupled to said fuel cell and electrolyzer, and an aircraft power load operatively coupled to said fuel cell and electrolyzer.

A vacuum system for use with a deoxygenator system includes a housing, a movable assembly positioned within the housing, and a biasing mechanism coupling the movable assembly to the housing. The movable assembly is movable between a first position and a second position within the housing to form a low pressure area between the housing and the movable assembly. A control system including at least one pressure source is arranged in fluid communication with the low pressure area. The control system is operable to selectively communicate fluid from the at least one pressure source to the housing to form the low pressure area.

An air separation module includes a cylindrical canister and a separator. The cylindrical canister has a longitudinal axis, an inlet, an oxygen-depleted air outlet, and a drain portion with an oxygen-enriched air outlet. The separator is arranged within the cylindrical canister to separate a compressed air flow into an oxygen-depleted air flow fraction and an oxygen-enriched air flow fraction, the oxygen-depleted air flow fraction provided to the oxygen-depleted air outlet and the oxygen-enriched air flow fraction to the drain portion of the canister. The drain portion extends tangentially from the cylindrical canister to issue the oxygen-enriched air flow fraction with entrained condensate from the oxygen-enriched air outlet with a tangential flow component. Nitrogen generation systems and methods of removing condensate from air separation modules are also described.

An oxygen generator for use in a passenger aircraft comprises an oxygen generating substance for generating oxygen gas after being activated; an activating substance for activating the oxygen generating substance; a pyroelectric igniter for igniting the activating substance upon receiving an electric trigger input; a housing defining a gas-tight chamber, accommodating the oxygen generating substance, the activating substance and the pyroelectric igniter; at least two electric conductors, coupled to the pyroelectric igniter and extending through a passage in the housing between an interior of the gas-tight chamber and an exterior of the gas-tight chamber; and at least one of a gas-tight glass-to-metal sealing and a gas-tight ceramic-to-metal sealing, sealing the at least two electric conductors with respect to the housing at the passage.

An onboard oxygen generation system for an aircraft is operatively connected to an oxygen tank of an oxygen supply system for the aircraft. The oxygen generation system includes an oxygen generator, a water source connected to the oxygen generator, and a power source connected to the oxygen generator. Oxygen produced by the oxygen generator from the water is supplied to the oxygen tank. Hydrogen gas produced by the oxygen generator can be combined with air to form water vapor and either discharged overboard the aircraft through a discharge vent or used to supply water to the water source.

An engine-driven cryogenic cooling system for an aircraft includes a first air cycle machine, a second air cycle machine, and a means for condensing a chilled air stream into liquid air for an aircraft use. The first air cycle machine includes a plurality of components operably coupled to a gearbox of a gas turbine engine and configured to produce a cooling air stream based on a first engine bleed source of the gas turbine engine. The second air cycle machine is operable to output the chilled air stream at a cryogenic temperature based on a second engine bleed source cooled by the cooling air stream of the first air cycle machine.

An aircraft air quality testing system includes a portable housing unit to be removably placed within an aircraft; an air testing unit secured inside the portable housing unit and including: a sensor to receive an air sample during a plurality of oxygen generation system cycles and engine thrust settings of the aircraft; a removable collection media to receive the air sample from the sensor and filter targeted chemicals from the air sample; and a plurality of analyzers to perform a real-time chemical analysis of the air sample and the filtered targeted chemicals. A first computer is operatively connected to the portable housing unit and includes: a processor to receive the real-time chemical analysis and generate real-time chemical analysis and flow rate data; a memory device to store the real-time chemical analysis and flow rate data; and a display device operatively connected to the portable housing unit.

An air separation unit for an OBOGS includes a housing having an inlet for receiving a wet inlet air and an outlet for outputting a dry product gas. The housing includes an outer side wall and annular walls defining a series of concentric annular chambers. A first annular chamber is coupled to the inlet and includes a desiccant material to receive the wet inlet air and output a dried air. An unfilled second annular chamber is coupled to the first annular chamber. A third annular chamber is coupled to the second annular chamber at a first end and the outlet at a second end. The third annular chamber receives air separation material to selectively remove unwanted constituents from the dried air and output the dry product gas. A tap may be coupled to the second annular chamber so that dried air may be removed from the housing.

A method of recovering performance of an air separation module (ASM) is described. A recovery system includes an air source providing inlet air, a filter to output clean air and a heater heating the air. The ASM is coupled to the system and comprises a hollow fiber membrane to output nitrogen enriched air (NEA) exhaust. The method comprises operating the system with the air source and heater in a default condition; measuring an initial purity of NEA exhaust; adjusting the air source and/or heater based on the initial purity; operating the system after adjusting the air source and/or heater; returning the air source and heater to the default condition; measuring a recovered purity of NEA exhaust; and determining whether the recovered purity is within tolerance. If the recovered purity is within tolerance, system operation is terminated. If the recovered purity is not within tolerance, the steps are repeated.

A retention system for use within a molecular sieve unit includes a perforated plate having a top face and bottom face. The perforated plate is configured to be positioned atop a packed sieve bed proximate an outlet end cap of the molecular sieve unit. A skirt is coupled to the bottom face of the perforated plate and a biasing member is configured to engage the outlet end cap and the top face of the perforated plate. The biasing member urges the perforated plate against the packed sieve bed. The biasing member may be one or more wave springs thereby reducing the risk of losing sufficient biasing force against the perforated plate. In the event that a sufficient biasing force is lost, the skirt may operate as a failsafe so as to minimize or prevent tilting of the perforated plate within the housing.