Abstract: A Reversible Solid Oxide Fuel Cell (RSOFC) system includes a Reversible Solid Oxide Fuel Cell (RSOFC) unit, a bi-directional alternating current/direct current (AC/DC) converter, coupled to the RSOFC unit, a common bus, coupled to the bi-directional AC/DC converter and to a power grid, and a plurality of RSOFC subsystems, coupled to receive power only through the common bus. The RSOFC unit has a fuel cell mode, wherein the RSOFC unit produces electrical power from fuel, and an electrolysis mode, wherein the RSOFC unit consumes electrical power to produce the fuel. The bi-directional AC/DC converter is coupled to the RSOFC unit, and is configured to convert direct current (DC) electrical power produced by the RSOFC unit into outgoing alternating current (AC) power, and to convert incoming AC power into DC power for consumption by the RSOFC unit in electrolysis mode.

Abstract: A method for passively removing water from a stream of hydrogen gas includes receiving a stream of hydrogen gas that is water-saturated, having an initial pressure below about 1 psig and an initial temperature above about 25° C., compressing the stream of hydrogen gas to an elevated pressure, chilling the compressed stream of hydrogen gas to a low temperature, and condensing water from the compressed and chilled stream of hydrogen gas until the water content of the stream of hydrogen gas is below about 100 ppm.

Abstract: A process control system includes a storage chamber, a fuel cell in fluid communication with the storage chamber via a feed line, a suction dampening drum in fluid communication with the fuel cell via a product line, a compressor in fluid communication with the suction dampening drum and the storage chamber, a recycle line disposed between the feed line and the product line, and a pressure controller disposed in the recycle line. When the fuel cell is in an electrolysis mode, the pressure controller may be operated to maintain a minimum pressure level inside the drum.

Abstract: Embodiments described herein provide for water reclamation from the exhaust stream of a RSOFC while the RSOFC operates in fuel cell mode. The reclaimed water is stored for use by the RSOFC while in electrolysis mode. An embodiment includes a RSOFC, a condensate tank, a condenser, and a controller. The RSOFC generates electrical power and water vapor by consuming hydrogen gas in the fuel cell mode, and consumes electrical power and water to generate the hydrogen gas in the electrolysis mode. The condenser condenses the water vapor into water, and directs the water to the condensate tank. The controller, responsive to transitioning the RSOFC from the fuel cell mode to the electrolysis mode, supplies the water to the RSOFC from the condensate tank, and supplies the electrical power to the RSOFC to electrolyze the water and to generate the hydrogen gas.

Abstract: A Reversible Solid Oxide Fuel Cell (RSOFC) system includes a Reversible Solid Oxide Fuel Cell (RSOFC) unit, a bi-directional alternating current/direct current (AC/DC) converter, coupled to the RSOFC unit, a common bus, coupled to the bi-directional AC/DC converter and to a power grid, and a plurality of RSOFC subsystems, coupled to receive power only through the common bus. The RSOFC unit has a fuel cell mode, wherein the RSOFC unit produces electrical power from fuel, and an electrolysis mode, wherein the RSOFC unit consumes electrical power to produce the fuel. The bi-directional AC/DC converter is coupled to the RSOFC unit, and is configured to convert direct current (DC) electrical power produced by the RSOFC unit into outgoing alternating current (AC) power, and to convert incoming AC power into DC power for consumption by the RSOFC unit in electrolysis mode.

Abstract: A Reversible Solid Oxide Fuel Cell (RSOFC) system includes a Reversible Solid Oxide Fuel Cell (RSOFC) unit, a bi-directional alternating current/direct current (AC/DC) converter, coupled to the RSOFC unit, a common bus, coupled to the bi-directional AC/DC converter and to a power grid, and a plurality of RSOFC subsystems, coupled to receive power only through the common bus. The RSOFC unit has a fuel cell mode, wherein the RSOFC unit produces electrical power from fuel, and an electrolysis mode, wherein the RSOFC unit consumes electrical power to produce the fuel. The bi-directional AC/DC converter is coupled to the RSOFC unit, and is configured to convert direct current (DC) electrical power produced by the RSOFC unit into outgoing alternating current (AC) power, and to convert incoming AC power into DC power for consumption by the RSOFC unit in electrolysis mode.

Abstract: Embodiments described herein provide for water reclamation from the exhaust stream of a RSOFC while the RSOFC operates in fuel cell mode. The reclaimed water is stored for use by the RSOFC while in electrolysis mode. An embodiment includes a RSOFC, a condensate tank, a condenser, and a controller. The RSOFC generates electrical power and water vapor by consuming hydrogen gas in the fuel cell mode, and consumes electrical power and water to generate the hydrogen gas in the electrolysis mode. The condenser condenses the water vapor into water, and directs the water to the condensate tank. The controller, responsive to transitioning the RSOFC from the fuel cell mode to the electrolysis mode, supplies the water to the RSOFC from the condensate tank, and supplies the electrical power to the RSOFC to electrolyze the water and to generate the hydrogen gas.

Abstract: A method for transitioning between fuel cell and electrolysis modes in a Reversible Solid Oxide Fuel Cell (RSOFC) system includes measuring and recording sensor data indicating a status of components associated with an RSOFC system coupled to an electrical power grid, the system comprising an RSOFC unit, a hydrogen compression system, a hydrogen storage system, and a water supply, determining a state of the RSOFC system based on the sensor data through a conditional logic algorithm, and transitioning the RSOFC system between the fuel cell mode and the electrolysis mode based upon the sensor data and the system state.

Abstract: Embodiments described herein provide for heat reclamation and temperature control of a SOFC for a submersible vehicle. The vehicle includes a SOFC, a hot box that surrounds the SOFC, a cooling loop, and a Stirling engine. The cooling loop has a heat exchanger and a coolant pump. The heat exchanger thermally couples the cooling loop to the water. The Stirling engine has a first end thermally coupled to an interior of the hot box and a second end thermally coupled to the cooling loop. The coolant pump modifies a rate of heat removal from the second end of the Stirling engine based on a pump control signal. A thermal management controller monitors a temperature of a cathode outlet of the SOFC, and modifies the pump control signal to maintain the temperature of the cathode outlet within a temperature range.

Abstract: Embodiments described herein provide for in-place refueling of reactant sources for submersible vehicles that utilize fuel cells. In one embodiment, the vehicle includes a pressure hull that maintains a pressure boundary between an interior surface and an exterior surface, and includes a fuel cell. The vehicle includes a reactant source tank for the fuel cell that includes a fill port for transferring a reactant source to the reactant source tank. The vehicle includes a pressure hull penetrator that traverses from the exterior surface to the interior surface utilizing a passage through the pressure hull. The pressure hull penetrator maintains the pressure boundary between the exterior surface and the interior surface. The vehicle includes a fill tube coupled to the fill port of the reactant source tank that traverses through the pressure hull penetrator to the exterior surface, and an electrically non-conductive sleeve surrounding the fill tube.

Abstract: Embodiments described herein provide for in-place refueling of reactant sources for submersible vehicles that utilize fuel cells. In one embodiment, the vehicle includes a pressure hull that maintains a pressure boundary between an interior surface and an exterior surface, and includes a fuel cell. The vehicle includes a reactant source tank for the fuel cell that includes a fill port for transferring a reactant source to the reactant source tank. The vehicle includes a pressure hull penetrator that traverses from the exterior surface to the interior surface utilizing a passage through the pressure hull. The pressure hull penetrator maintains the pressure boundary between the exterior surface and the interior surface. The vehicle includes a fill tube coupled to the fill port of the reactant source tank that traverses through the pressure hull penetrator to the exterior surface, and an electrically non-conductive sleeve surrounding the fill tube.

Abstract: A process control system includes a storage chamber, a fuel cell in fluid communication with the storage chamber via a feed line, a suction dampening drum in fluid communication with the fuel cell via a product line, a compressor in fluid communication with the suction dampening drum and the storage chamber, a recycle line disposed between the feed line and the product line, and a pressure controller disposed in the recycle line. When the fuel cell is in an electrolysis mode, the pressure controller may be operated to maintain a minimum pressure level inside the drum.

Abstract: A Reversible Solid Oxide Fuel Cell (RSOFC) system includes a Reversible Solid Oxide Fuel Cell (RSOFC) unit, a bi-directional alternating current/direct current (AC/DC) converter, coupled to the RSOFC unit, a common bus, coupled to the bi-directional AC/DC converter and to a power grid, and a plurality of RSOFC subsystems, coupled to receive power only through the common bus. The RSOFC unit has a fuel cell mode, wherein the RSOFC unit produces electrical power from fuel, and an electrolysis mode, wherein the RSOFC unit consumes electrical power to produce the fuel. The bi-directional AC/DC converter is coupled to the RSOFC unit, and is configured to convert direct current (DC) electrical power produced by the RSOFC unit into outgoing alternating current (AC) power, and to convert incoming AC power into DC power for consumption by the RSOFC unit in electrolysis mode.

Abstract: A method for passively removing water from a stream of hydrogen gas includes receiving a stream of hydrogen gas that is water-saturated, having an initial pressure below about 1 psig and an initial temperature above about 25° C., compressing the stream of hydrogen gas to an elevated pressure, chilling the compressed stream of hydrogen gas to a low temperature, and condensing water from the compressed and chilled stream of hydrogen gas until the water content of the stream of hydrogen gas is below about 100 ppm.

Abstract: A method for transitioning between fuel cell and electrolysis modes in a Reversible Solid Oxide Fuel Cell (RSOFC) system includes measuring and recording sensor data indicating a status of components associated with an RSOFC system coupled to an electrical power grid, the system comprising an RSOFC unit, a hydrogen compression system, a hydrogen storage system, and a water supply, determining a state of the RSOFC system based on the sensor data through a conditional logic algorithm, and transitioning the RSOFC system between the fuel cell mode and the electrolysis mode based upon the sensor data and the system state.

Abstract: Embodiments described herein provide for heat reclamation and temperature control of a SOFC for a submersible vehicle. The vehicle includes a SOFC, a hot box that surrounds the SOFC, a cooling loop, and a Stirling engine. The cooling loop has a heat exchanger and a coolant pump. The heat exchanger thermally couples the cooling loop to the water. The Stirling engine has a first end thermally coupled to an interior of the hot box and a second end thermally coupled to the cooling loop. The coolant pump modifies a rate of heat removal from the second end of the Stirling engine based on a pump control signal. A thermal management controller monitors a temperature of a cathode outlet of the SOFC, and modifies the pump control signal to maintain the temperature of the cathode outlet within a temperature range.