Abstract: A fuel cell system includes a fuel cell configured to produce electrical power by a chemical reaction of a flow of fuel and a flow of oxygen or air with an electrolyte and a cooling system configured to remove thermal energy from the fuel cell via a flow of coolant through the fuel cell. The fuel cell system includes one or more conductivity sensors configured to measure a change in conductivity of the coolant flow. A method of operating a fuel cell system includes producing electrical power at a fuel cell by a chemical reaction of a flow of fuel and a flow of air with an electrolyte, urging a flow of coolant through the fuel cell to remove thermal energy and ions from the fuel cell, and measuring a conductivity of the flow of coolant via one or more conductivity sensors.

Abstract: A fuel cell system includes a fuel cell configured to produce electrical power by a chemical reaction of a flow of fuel and a flow of oxygen or air with an electrolyte and a cooling system configured to remove thermal energy from the fuel cell via a flow of coolant through the fuel cell. The fuel cell system includes one or more conductivity sensors configured to measure a change in conductivity of the coolant flow. A method of operating a fuel cell system includes producing electrical power at a fuel cell by a chemical reaction of a flow of fuel and a flow of air with an electrolyte, urging a flow of coolant through the fuel cell to remove thermal energy and ions from the fuel cell, and measuring a conductivity of the flow of coolant via one or more conductivity sensors.

Abstract: A method for detecting a leak in a closed-volume liquid system comprises circulating a fluid through a closed-loop with a pump having a reservoir and that is driven by an electric motor. The method also comprises sensing a pressure in the closed-loop, sensing current draw by the motor and sensing fluid level in the reservoir. The method further comprises determining a presence of a leak of fluid from the closed-loop based upon two of the sensed signals using a first leak detection logic, and determining the presence of a leak of fluid from the closed-loop based upon at least one of the sensed signals using a second leak detection logic.

Abstract: A method for isolating a leak in a closed-volume liquid system comprises circulating a fluid through a plurality of isolatable zones and a non-isolatable zone in a closed-volume liquid system, detecting a leak in the closed-volume liquid system, isolating all of the isolatable zones from the non-isolatable zone, sequentially detecting if the leak is present in the non-isolatable zone and each of isolatable zones, and taking corrective action after the leak is detected.

Abstract: A method for detecting a leak in a closed-volume liquid system comprises circulating a fluid through a closed-loop with a pump having a reservoir and that is driven by an electric motor. The method also comprises sensing a pressure in the closed-loop, sensing current draw by the motor and sensing fluid level in the reservoir. The method further comprises determining a presence of a leak of fluid from the closed-loop based upon two of the sensed signals using a first leak detection logic, and determining the presence of a leak of fluid from the closed-loop based upon at least one of the sensed signals using a second leak detection logic.

Abstract: A method for isolating a leak in a closed-volume liquid system comprises circulating a fluid through a plurality of isolatable zones and a non-isolatable zone in a closed-volume liquid system, detecting a leak in the closed-volume liquid system, isolating all of the isolatable zones from the non-isolatable zone, sequentially detecting if the leak is present in the non-isolatable zone and each of isolatable zones, and taking corrective action after the leak is detected.

Abstract: Substantially pure oxygen is provided to an up flow reformer (49a) from a separator (108) downwardly impelled water droplets (53) mix with the outflow (58) of a CPO (59), flowing upwardly through high temperature (68) and low temperature (73) water gas shift reactors. The reformer output flows through a mixer (79) to a down-flow PrOx containing two beds (82, 94) of preferential CO oxidation catalyst therein. A series of compressors (120-122) compress water and carbon dioxide out of the gaseous flow to provide pure, pressurized hydrogen. Oxygen (111) is separated (105, 108) from nitrogen (112).

Abstract: An autothermal reformer or a catalytic partial oxidizer (19) receives flow of desulfurized hydrocarbon fuel from a hydrogen desulfurizer (HDS) (15) through an orifice (13a). A differential pressure transducer (13b) provides a signal (24a) to a fuel-flow differential-pressure schedule (13c) to provide a fuel flow signal (24b) which is (25) subtracted from fuel command (26), to provide a valve position signal 30a from a proportional/integral gain (29), being linearized (58) to control the fuel valve (12). The minimum (59) of actual fuel flow (24b) and fuel flow command (59) is applied to an air/fuel schedule (33). The resulting air flow command is compared with actual air flow (41b) to provide an air flow control signal 48a which is linearized (60) after proportional/integral gain (47) to provide air flow command (48b) to a blower (49). Differential pressure (42b) across an orifice (42a) is provided to a schedule (42c) which converts to the actual air flow feedback (41b).

Abstract: Substantially pure oxygen is provided to an up flow reformer (49a) from a separator (108) downwardly impelled water droplets (53) mix with the outflow (58) of a CPO (59), flowing upwardly through high temperature (68) and low temperature (73) water gas shift reactors. The reformer output flows through a mixer (79) to a down-flow PrOx containing two beds (82, 94) of preferential CO oxidation catalyst therein. A series of compressors (120-122) compress water and carbon dioxide out of the gaseous flow to provide pure, pressurized hydrogen. Oxygen (111) is separated (105, 108) from nitrogen (112).

Abstract: A hydrogen desulfurizer (11) includes a tank (17) designed for downflow of hydrocarbon feedstock containing a plurality of layers (41-44) of catalyst interspersed with layers (46-49) of adsorbent. The layers may all comprise baskets, the adsorbent comprising pellets, such as zinc oxide pellets; the catalysts may be wash-coated on catalyst support such as monolith or foams, or may be wash-coated on netted wire mesh instead of being contained in a basket. The catalyst is heated to between about 442° F. (250° C.) and about 932° F. (500° C.). A mini-CPO (36) supplies hydrogen to the desulfurizer (11). Heaters (53, 55), which may either be electric or circulating heated fluid may also be used.

Abstract: Oxides of nitrogen are adsorbed onto the surfaces of gas passages (68) in a bed (57, 100) that has relative rotation with respect to a gas inlet distributor (76, 101). The manifold has a baffle (85) or ribs (121, 122) that causes constantly flowing engine exhaust (53) to enter the gas passages over a large portion of a revolution of the adsorption bed or the distributor, and causes constantly flowing regeneration gas (54) to thereafter pass through those passages during a small portion of each revolution. The passages may be formed by planar (66a) or helical (66b) radial walls (66), a serpentine wall (70), a monolith (126), or a honeycomb (127). Either the distributor (101) or the bed (57) may be rotated to distribute the gases.

Abstract: Oxides of nitrogen are adsorbed onto the surfaces of gas passages (68) in a bed (57, 100) that has relative rotation with respect to a gas inlet distributor (76, 101). The manifold has a baffle (85) or ribs (121, 122) that causes constantly flowing engine exhaust (53) to enter the gas passages over a large portion of a revolution of the adsorption bed or the distributor, and causes constantly flowing regeneration gas (54) to thereafter pass through those passages during a small portion of each revolution. The passages may be formed by planar (66a) or helical (66b) radial walls (66), a serpentine wall (70), a monolith (126), or a honeycomb (127). Either the distributor (101) or the bed (57) may be rotated to distribute the gases.

Abstract: An electronic control for an air conditioning system is provided. The system includes first and second air conditioning packs located in the air craft remote from one another. Each pack includes a pack controller in the same location as the pack. The pack controllers produce operating instruction signals to the packs for instructing the packs to produce conditioned air in response to a reference signal. A supervisory controller is centrally located in aircraft, preferably in the electronics equipment bay, and is connected to each of the pack controllers. The supervisory controller produces the reference signal to the pack controllers. In addition to controlling the operation of the packs, the pack controllers preferably include prognostics for monitoring the packs and diagnosing problems. The distributed electronic controllers of the present invention utilized for the packs may similarly be applied to the zone trim system and the engine air bleed valves.

Abstract: An electronic control for an air conditioning system is provided. The system includes first and second air conditioning packs located in the air craft remote from one another. Each pack includes a pack controller in the same location as the pack. The pack controllers produce operating instruction signals to the packs for instructing the packs to produce conditioned air in response to a reference signal. A supervisory controller is centrally located in aircraft, preferably in the electronics equipment bay, and is connected to each of the pack controllers. The supervisory controller produces the reference signal to the pack controllers. In addition to controlling the operation of the packs, the pack controllers preferably include prognostics for monitoring the packs and diagnosing problems. The distributed electronic controllers of the present invention utilized for the packs may similarly be applied to the zone trim system and the engine air bleed valves.