Abstract: A method of operating a fuel cell system includes providing fuel and air to a stack of fuel cells located in a hotbox, operating the stack to generate an anode exhaust and a cathode exhaust, in a startup mode, providing a first amount of the anode exhaust and the cathode exhaust to an anode tail gas oxidizer (ATO) located in the hotbox to oxidize the anode exhaust and to generate heat which is provided to the stack, and in a steady-state mode, stopping providing the anode exhaust to the ATO or providing to the ATO a second amount of the anode exhaust which is smaller than the first amount, and providing the anode exhaust and the cathode exhaust outside the hotbox.

Abstract: A fuel cell system conduit assembly includes a dielectric tube having a first end and a second end, a metallic first flange press-fit to the first end of the dielectric tube, a metallic second flange press-fit to the second end of the dielectric tube, a first snap ring disposed between the first flange and the dielectric tube, and a second snap ring disposed between the second flange and the dielectric tube.

Abstract: A fuel cell system includes at least one electrochemical pump separator to separate hydrogen and carbon dioxide from a fuel exhaust stream.

Abstract: A fuel cell system includes at least one spark igniter containing an insulated cable where at least a first end of the insulated cable is positioned within a reaction zone of the fuel cell system. A power supply is configured to provide a direct current (DC) voltage to the at least one spark igniter such that a spark is generated at the first end of the insulated cable.

Abstract: A fuel cell column includes a plurality of fuel cell stacks, at least one fuel manifold configured to provide fuel to the plurality of fuel cell stacks, and at least one heat sink insert located between adjacent fuel cells of the plurality of fuel cell stacks. A fuel cell column including at least one heat sink insert located between adjacent fuel cell stacks of the column may reduce the peak temperatures of the fuel cell stacks adjacent to the heat sink inserts and may provide a smaller temperature distribution within the fuel cell stacks and within the column as a whole.

Abstract: Various embodiments of a reactant feed and return assembly, such as an anode splitter plate (ASP), are provided for facilitating reactant feed flow in a solid oxide fuel cell (SOFC) stack system. Embodiments include a reactant feed and return assembly including at least one nozzle structure along a flow path of a reactant feed to a fuel cell stack. The at least one nozzle structure may include a width dimension that decreases along the flow path of the reactant. The at least one nozzle structure of the assembly may accelerate the reactant feed as it enters the adjacent fuel cell stack and may provide the reactant feed with sufficient kinetic energy to negate the effects of an increase in viscous resistance along the reactant flow path through the fuel cell stack.

Abstract: A method of operating a fuel cell system includes providing an anode exhaust from a fuel cell stack to a water injector, supplying water to the water injector, and injecting the water from the water injector into the anode exhaust to vaporize the water and generate a humidified anode exhaust.

Abstract: A method of operating a fuel cell system includes providing fuel and air to a stack of fuel cells located in a hotbox, operating the stack to generate an anode exhaust and a cathode exhaust, in a startup mode, providing a first amount of the anode exhaust and the cathode exhaust to an anode tail gas oxidizer (ATO) located in the hotbox to oxidize the anode exhaust and to generate heat which is provided to the stack, and in a steady-state mode, stopping providing the anode exhaust to the ATO or providing to the ATO a second amount of the anode exhaust which is smaller than the first amount, and providing the anode exhaust and the cathode exhaust outside the hotbox.

Abstract: A fuel cell system anode tail gas oxidizer (ATO) includes an inner ATO wall, an outer ATO wall, and a first catalyst ring disposed in a chamber formed between the inner ATO wall and the outer ATO wall. The first catalyst ring includes an inner wall, an outer wall, and a matrix disposed between the inner wall and the outer wall and loaded with an oxidation catalyst.

Abstract: A fuel cell system includes a fuel cell stack, an anode tail gas oxidizer (ATO), an ATO injector configured to mix a first portion of an anode exhaust from the fuel cell stack with a cathode exhaust from the fuel cell stack and to provide a mixture of the first portion of the anode exhaust and the cathode exhaust into the ATO, an anode exhaust conduit which is configured to provide the first portion of the anode exhaust into the ATO injector, and cathode exhaust conduit which is configured to provide at least a portion of the cathode exhaust from the fuel cell stack into the ATO injector. The ATO injector includes injector tubes or injection apertures.

Abstract: A fuel cell system includes a fuel cell stack, an anode tail gas oxidizer (ATO), an ATO injector configured to mix a first portion of an anode exhaust from the fuel cell stack with a cathode exhaust from the fuel cell stack and to provide a mixture of the first portion of the anode exhaust and the cathode exhaust into the ATO, an anode exhaust conduit which is configured to provide the first portion of the anode exhaust into the ATO injector, and cathode exhaust conduit which is configured to provide at least a portion of the cathode exhaust from the fuel cell stack into the ATO injector. The ATO injector includes injector tubes or injection apertures.

Abstract: A fuel cell stack fuel plenum includes a base plate including an inlet hole and an outlet hole, a dielectric layer disposed on the base plate and including an inlet hole and an outlet hole, a cover plate disposed on the dielectric layer and including an inlet hole and an outlet hole, a seal plate disposed on the cover plate and including an inlet hole and an outlet hole, and a manifold plate disposed on the seal plate. The manifold plate includes a bottom inlet hole and a bottom outlet hole formed in a bottom surface of the manifold plate, top outlet holes and top inlet holes formed in opposing sides of a top surface of the manifold plate, outlet channels fluidly connecting the top outlet holes to the bottom inlet hole, and inlet channels fluidly connecting the top inlet holes to the bottom outlet hole.

Abstract: A fuel cell column includes first and second fuel cell stacks, a fuel manifold disposed between the first and second fuel cell stacks and configured to provide fuel to the first and second fuel cell stacks, and first and second dielectric separators located between the fuel manifold and the respective first and second fuel cell stacks, and configured to electrically isolate the respective first and second fuel cell stacks from the fuel manifold. The first and second dielectric separators each include a top layer of a ceramic material, a bottom layer of the ceramic material, a middle layer disposed between the top and bottom layers and including a material having a lower density and a higher dielectric strength than the ceramic material, and glass or glass ceramic seals which connect the middle layer to the top and bottom layers.

Abstract: A fuel cell device includes at least one fuel cell column containing first and second fuel cell stacks, a fuel manifold located between the first and second fuel cell stacks and configured to provide fuel to the first and second fuel cell stacks, and a dielectric material located to electrically isolate the first and second fuel cell stacks from the fuel manifold.

Abstract: A method of operating a fuel cell system includes providing an anode exhaust from a fuel cell stack to a water injector, supplying water to the water injector, and injecting the water from the water injector into the anode exhaust to vaporize the water and generate a humidified anode exhaust.

Abstract: A method of operating a fuel cell system includes providing an anode exhaust from a fuel cell stack to a water injector, supplying water to the water injector, and injecting the water from the water injector into the anode exhaust to vaporize the water and generate a humidified anode exhaust.

Abstract: A fuel cell column includes first and second fuel cell stacks, a fuel manifold disposed between the first and second fuel cell stacks and configured to provide fuel to the first and second fuel cell stacks, and first and second dielectric separators located between the fuel manifold and the respective first and second fuel cell stacks, and configured to electrically isolate the respective first and second fuel cell stacks from the fuel manifold. The first and second dielectric separators each include a top layer of a ceramic material, a bottom layer of the ceramic material, a middle layer disposed between the top and bottom layers and including a material having a lower density and a higher dielectric strength than the ceramic material, and glass or glass ceramic seals which connect the middle layer to the top and bottom layers.

Abstract: A fuel cell system conduit assembly includes a dielectric tube having a first end and a second end, a metallic first flange press-fit to the first end of the dielectric tube, a metallic second flange press-fit to the second end of the dielectric tube, a first snap ring disposed between the first flange and the dielectric tube, and a second snap ring disposed between the second flange and the dielectric tube.

Abstract: A fuel cell system includes a plurality of fuel cell stacks or columns, each fuel cell stack or column containing a plurality of fuel cells, and at least one pressure drop tool located in a fuel path of at least one first fuel cell stack or column but not in a fuel path of at least one second fuel cell stack or column.

Abstract: One method of operating a fuel cell system including splitting a cathode exhaust from one or more fuel cell stacks in the system into a majority cathode exhaust stream comprising more than 50% of the cathode exhaust and a first cathode exhaust bypass stream, providing the majority cathode exhaust stream to an inlet of an anode tail gas oxidizer (ATO) containing a catalyst and providing the first cathode bypass stream downstream of the catalyst such that it bypasses the catalyst. Another method includes providing an air inlet stream to the SOFC system via a main air inlet, providing the air inlet stream from the main air inlet to a cathode recuperator, and providing a cooling medium to a heat exchanger to cool the cathode recuperator.