Oxygen Flow Regulation Techniques in Fuel Cells

High efficiency solid oxide fuel cell system that recycles the anode exhaust gases to extract hydrogen fuel while also oxidizing the remaining gases. The system includes pumps that extract hydrogen from the anode exhaust in stages, providing the extracted hydrogen back to the fuel cell stack and oxidizing the remaining exhaust gases. This allows purification of the hydrogen fuel and recovery of unspent fuel from the exhaust, improving system efficiency.

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Fuel cell system control method for improved safety, reliability, simplicity, weight reduction, and space reduction of fuel cell systems. The control involves steps like supplying hydrogen before gas containing oxygen, discharging oxygen gas when voltage reaches a reference level, and circulating oxygen gas to avoid carbon corrosion. This prevents dangerous radical reactions and potential fuel cell breakdown. The method also depressurizes the system at startup, monitors impedance, and increases current density gradually.

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Proton exchange membrane fuel cell (PEMFC) design that prevents water buildup and oxygen starvation. The PEMFC has separate hydrogen and oxygen inlets. The oxygen inlet has a hydrophobic layer to prevent water ingress, while the hydrogen inlet has a hydrophobic layer to only allow hydrogen. This prevents water from reaching the hydrogen inlet. The water produced at the cathode exits through a hydrophilic outlet that only allows water molecules, preventing clogging.

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A self-refueling power-generating system that can operate in a self-sustained manner, using no external resource for water, oxygen or hydrogen. The key idea is to configure a reversible fuel cell/electrolyzer device to have closed circuits for supplying/receiving oxygen, hydrogen, and water/dilute electrolyte. It can be used to provide efficient and economical energy storage and delivery. It involves determining the operation of reversible device(s) in fuel cell or electrolyzer mode according to power requirements and power availability, supplying and receiving oxygen in a closed circuit, compressing received oxygen in the electrolyzer mode, and supplying and receiving water or dilute electrolyte in a closed circuit in conjunction with the closed oxygen supply circuit by separating oxygen produced by the reversible device(s) in the electrolyzer mode from the water or dilute electrolyte received from the reversible device(s).

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Membrane-electrode assembly (MEA) for proton exchange membrane fuel cells that can prevent corrosion of carbon supports and platinum loss when hydrogen supply is reduced without sacrificing performance. The MEA includes a proton exchange membrane with an anode on one side, a cathode on the other side, and an oxygen evolution reaction (OER) catalyst layer in contact with the anode to inhibit carbon oxidation. The OER catalyst layer prevents carbon support corrosion and platinum loss when hydrogen supply is reduced.

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A system for recovering fuel cell performance by periodically cleaning oxide films from the fuel cell using hydrogen fuel. The system monitors the fuel cell's power output and when it drops below a threshold, indicating performance degradation, it prevents oxygen supply and discharges, converts the fuel cell's power output through an inverter without supplying externally, and supplies hydrogen to the cathode to clean oxide films from the platinum catalyst. This recovery process is stopped when voltage reaches a predetermined reference value.

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A fuel cell powered aircraft that converts between using ambient air and stored oxygen to power the fuel cell, allowing operation above 15,000 feet where air oxygen is too low for normal fuel cells. The aircraft has a fuel cell cathode that can switch between air and oxygen, allowing it to use ambient air at lower altitudes, then switch to using stored oxygen at higher altitudes where air oxygen is insufficient. The switching can be automated based on flight parameters, atmospheric conditions, power demands, etc. This allows the aircraft to efficiently use ambient air when possible, while having the oxygen option for high altitude flight.

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Fuel cell module for vehicles with an auxiliary device case to house fuel and oxygen systems. The case has a protection mechanism to prevent damage to fuel devices when a load is applied. The mechanism includes a protruding pipe that has a weak point designed to break when overloaded. The break point on the pipe prevents forces from transferring to the fuel system if a load is applied to the oxygen system.

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Non-precious metal catalyst system for fuel cells and electrolyzers that has comparable oxygen reduction activity to platinum, but lower cost. The catalyst system comprises an electrically conductive carrier metal oxide and a metal oxide catalyst material. The carrier metal oxide has at least two non-precious metal elements in a solid stoichiometric compound or solution. The catalyst material has at least one non-noble metal element in a solid stoichiometric compound or solution. The carrier and catalyst oxides are doped with fluorine, nitrogen, carbon, boron, and optionally hydrogen. The doped oxides exhibit good oxygen reduction reaction electrocatalysis.

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Restarting a fuel cell without damaging its components. The method involves supplying oxygen to the cathode electrode before recharging the fuel cell stack. This prevents combustion reactions that can degrade the fuel cell during restart. A fan, pump or blower powered by a battery provides the oxygen flow. The fan power requirement is lower than the normal operating blower.

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Fuel cell system for efficiently recovering byproducts like CO2 and water from anode exhaust of solid oxide fuel cells (SOFCs) while reducing pollution. The system uses a combustion chamber to burn excess fuel, but instead of air, an oxygen enriched gas is used to reduce nitrogen and argon levels in the exhaust. This enables efficient recovery of CO2 and water for reuse.

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A fuel cell system that prevents oxygen corrosion and hydrogen safety risks when the system is stopped. The system has dedicated spaces for oxygen and hydrogen to stay when the system is stopped. A control unit adjusts the oxygen-to-hydrogen ratio in those spaces to prevent issues.

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A regenerative fuel cell system that produces hydrogen and oxygen fuel by electrolyzing water. The system has separate valves to return any crossover gases back to their storage tanks. When oxygen accompanies the hydrogen produced, the hydrogen and oxygen react to remove the oxygen before returning the pure hydrogen to storage. Likewise, if hydrogen accompanies the oxygen, they react to remove the hydrogen before returning the pure oxygen to storage. This prevents crossover gases from reaching the wrong tanks and potentially causing fires or explosions.

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A solid oxide fuel cell (SOFC) system that produces electricity, hydrogen and refined carbon dioxide simultaneously from liquid hydrocarbon fuel like gasoline or diesel. The system uses a series of process steps and components, including a hydrodesulfurization unit, steam reformer, water-gas shift reactor, fuel cell, oxygen generator, and CO2 purification system. It also incorporates hydrogen compression and storage for fueling fuel cell vehicles and an electrical output for powering electric vehicles.

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A solid oxide fuel cell (SOFC) system and method that can simultaneously produce electricity, hydrogen and refined carbon dioxide from a liquid hydrocarbon fuel. The SOFC system includes components like a hydrodesulfurization system, steam reformer, water-gas shift reactor, hydrogen purification system, and oxygen generator. By controlling the process conditions and feed ratios, it can optimize hydrogen, electricity and carbon dioxide production based on the hydrocarbon fuel source.

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