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US 12,586,798 B2Granted
Methods and apparatus for mold mitigation in fuel cell humidifiers
AssigneeCevizdere LLC
InventorsSean Michael Mackinnon, Matthew Guenther, Claudette Kennette
Life of this patent
Estimating the term…
Abstract
Methods and apparatus for reducing the tendency for mold formation and accumulation in membrane-based humidifiers used in PEM fuel cell systems can include reducing the oxygen concentration and/or generating hydrogen peroxide within the humidifier upon shutdown of a fuel cell system. In some embodiments, a fuel cell system comprises valves and lines located and operable to facilitate introduction of hydrogen into the humidifier upon shutdown of the system. In some embodiments, a fuel cell humidifier comprises a catalyst for promoting the generation of hydrogen peroxide from hydrogen and oxygen, and/or comprises acidic gas transport layers.
Claims20
A method of operating a fuel cell system, said fuel cell system comprising:
- a humidifier having a dry-side compartment and a wet-side compartment, said dry-side compartment separated from said wet-side compartment by a water transfer membrane;
- and
- a fuel cell stack comprising an anode compartment and a cathode compartment, said anode compartment separated from said cathode compartment by a proton-exchange membrane;
- wherein, in an electrical power-producing mode of operation, said method comprises:
- supplying hydrogen to said anode compartment of said fuel cell stack;
- supplying air to said cathode compartment of said fuel cell stack via said dry-side compartment of said humidifier;
- discharging oxygen-depleted air from said cathode compartment of said fuel cell stack, and directing it through said wet-side compartment of said humidifier, whereby said air supplied to said cathode compartment of said fuel cell stack is humidified by said oxygen-depleted air discharged from said cathode compartment of said fuel cell stack;
- and
- drawing electrical power from said fuel cell stack;
- and
- wherein, in a shutdown mode, said method comprises:
- interrupting supplying hydrogen to said anode compartment of said fuel cell stack;
- interrupting supplying air to said cathode compartment of said fuel cell stack;
- and
- allowing hydrogen to diffuse from said anode compartment to said cathode compartment of said fuel cell stack via said proton-exchange membrane, and from said cathode compartment of said fuel cell stack to said dry-side compartment of said humidifier and to said wet-side compartment of said humidifier, whereby at least a portion of said diffused hydrogen reacts to consume oxygen in said cathode compartment of said fuel cell stack,
- wherein said supplying hydrogen to said anode compartment of said fuel cell stack comprises supplying hydrogen to said anode compartment of said fuel cell stack from a hydrogen supply via a fuel recirculation loop,
- wherein, in said shutdown mode, said method comprises providing hydrogen from a fuel supply to at least one of said dry-side compartment or said wet-side compartment of said humidifier,
- wherein said hydrogen is supplied from said fuel supply to at least one of said dry-side compartment or said wet-side compartment of said humidifier via a line that bypasses said fuel cell stack.
15 more elements
A fuel cell system comprising:
- a fuel cell stack;
- an oxidant supply device for supplying air to said fuel cell stack;
- a humidifier for humidifying air supplied by said oxidant supply device to said fuel cell stack, said humidifier having a dry-side compartment and a wet-side compartment, wherein said dry-side compartment and said wet-side compartment are separated by a water transfer membrane;
- a first air supply line between said oxidant supply device and said dry-side compartment of said humidifier;
- a second air supply line between said dry-side compartment of said humidifier and an oxidant inlet of said fuel cell stack, for directing humidified air from said humidifier to said fuel cell stack;
- a first exhaust line connected between an oxidant outlet of said fuel cell stack and said wet-side compartment of said humidifier, for supplying an oxidant exhaust gas discharged from said fuel cell stack to said wet-side compartment of said humidifier to humidify air supplied by said oxidant supply device to said fuel cell stack;
- a second exhaust line for discharging an exhaust stream from said wet-side compartment of said humidifier;
- a first valve installed in said first air supply line, wherein said first valve is for selectively opening and closing said first air supply line;
- and
- a second valve installed in said second exhaust line wherein said second valve is for selectively opening and closing said second exhaust line,
- wherein said humidifier comprises an acidic gas transport layer positioned adjacent at least one side of said water transfer membrane.
8 more elements
A fuel cell system comprising:
- a fuel cell stack;
- an oxidant supply device for supplying air to said fuel cell stack;
- a humidifier for humidifying air supplied by said oxidant supply device to said fuel cell stack, said humidifier having a dry-side compartment and a wet-side compartment, wherein said dry-side compartment and said wet-side compartment are separated by a water transfer membrane;
- a first air supply line between said oxidant supply device and said dry-side compartment of said humidifier;
- a second air supply line between said dry-side compartment of said humidifier and an oxidant inlet of said fuel cell stack, for directing humidified air from said humidifier to said fuel cell stack;
- a first exhaust line connected between an oxidant outlet of said fuel cell stack and said wet-side compartment of said humidifier, for supplying an oxidant exhaust gas discharged from said fuel cell stack to said wet-side compartment of said humidifier to humidify air supplied by said oxidant supply device to said fuel cell stack;
- a second exhaust line for discharging an exhaust stream from said wet-side compartment of said humidifier;
- a first valve installed in said first air supply line, wherein said first valve is for selectively opening and closing said first air supply line;
- and
- a second valve installed in said second exhaust line wherein said second valve is for selectively opening and closing said second exhaust line;
- a fuel supply device and a fuel recirculation loop for circulating a fuel through said fuel cell stack;
- and
- a fuel bleed line fluidly connecting said fuel recirculation loop to said first exhaust line, said fuel bleed line comprising a purge valve for selectively bleeding fuel from said fuel recirculation loop into said wet-side compartment of said humidifier via said first exhaust line.
10 more elements
A fuel cell system comprising:
- a fuel cell stack;
- an oxidant supply device for supplying air to said fuel cell stack;
- a humidifier for humidifying air supplied by said oxidant supply device to said fuel cell stack, said humidifier having a dry-side compartment and a wet-side compartment, wherein said dry-side compartment and said wet-side compartment are separated by a water transfer membrane;
- a first air supply line between said oxidant supply device and said dry-side compartment of said humidifier;
- a second air supply line between said dry-side compartment of said humidifier and an oxidant inlet of said fuel cell stack, for directing humidified air from said humidifier to said fuel cell stack;
- a first exhaust line connected between an oxidant outlet of said fuel cell stack and said wet-side compartment of said humidifier, for supplying an oxidant exhaust gas discharged from said fuel cell stack to said wet-side compartment of said humidifier to humidify air supplied by said oxidant supply device to said fuel cell stack;
- a second exhaust line for discharging an exhaust stream from said wet-side compartment of said humidifier;
- a first valve installed in said first air supply line, wherein said first valve is for selectively opening and closing said first air supply line;
- a second valve installed in said second exhaust line wherein said second valve is for selectively opening and closing said second exhaust line;
- a fuel supply device and a fuel recirculation loop for circulating a fuel through said fuel cell stack;
- and
- a fuel bypass line fluidly connecting at least one of said wet-side compartment or said dry-side compartment of said humidifier to a fuel supply, said fuel bypass line comprising a valve for controlling supply of fuel from said fuel supply to said humidifier.
9 more elements
Dependencies are inferred from the claim text.