Abstract: This invention relates to a fuel cell system comprising a fuel cell stack and a heat exchanger wrapped around the stack. The fuel cell stack comprises a fuel cell that operates at high elevated temperatures, such as a solid oxide fuel cell; the fuel cell can have a tubular configuration and comprise a pair of concentrically arranged electrode layers sandwiching a concentrically arranged electrolyte layer. The heat exchanger wraps around the fuel cell stack and comprises a flexible, thermally conductive first layer and an overlapping flexible, thermally conductive second layer spaced from the first layer. The first and second layers define adjacent annular oxidant supply and oxidant exhaust channels when wrapped around the stack.

Abstract: This invention relates to a solid oxide fuel cell system comprising at least one longitudinally extending tubular solid oxide fuel cell and a longitudinally extending heater mounted in thermal proximity to the fuel cell to provide heat to the fuel cell during start up and during operation as needed. The heater and fuel cell can be encased within a tubular thermal casing; the inside of the casing defines a first reactant chamber for containing a first reactant, such as oxidant. The fuel cell comprises a ceramic solid state electrolyte layer and inner and outer electrode layers concentrically arranged around and sandwiching the electrolyte layer. The outer electrode layer is fluidly communicable with the first reactant, and the inner electrode layer is fluidly isolated from the first reactant and fluidly communicable with a second reactant, such as fuel.

Abstract: This invention relates to a solid oxide fuel cell system comprising at least one longitudinally extending tubular solid oxide fuel cell and a longitudinally extending heater mounted in thermal proximity to the fuel cell to provide heat to the fuel cell during start up and during operation as needed. The heater and fuel cell can be encased within a tubular thermal casing; the inside of the casing defines a first reactant chamber for containing a first reactant, such as oxidant. The fuel cell comprises a ceramic solid state electrolyte layer and inner and outer electrode layers concentrically arranged around and sandwiching the electrolyte layer. The outer electrode layer is fluidly communicable with the first reactant, and the inner electrode layer is fluidly isolated from the first reactant and fluidly communicable with a second reactant, such as fuel.

Abstract: This invention relates to a fuel cell system comprising a fuel cell stack and a heat exchanger wrapped around the stack. The fuel cell stack comprises a fuel cell that operates at high elevated temperatures, such as a solid oxide fuel cell; the fuel cell can have a tubular configuration and comprise a pair of concentrically arranged electrode layers sandwiching a concentrically arranged electrolyte layer. The heat exchanger wraps around the fuel cell stack and comprises a flexible, thermally conductive first layer and an overlapping flexible, thermally conductive second layer spaced from the first layer. The first and second layers define adjacent annular oxidant supply and oxidant exhaust channels when wrapped around the stack.

Abstract: A thermophotovoltaic device (10) includes an energy source (12) compatible with thermophotovoltaic cells and thermophotovoltaic cells (14). A filter (16), adapted to filter out long wavelength energy, is positioned between the energy source (12) and the thermophotovoltaic cells (14). The filter (16) has dual walls (30 & 32) with a low conductivity space (34) between the walls (30 & 32) which is adapted to break the convection heat transfer path from the energy source (12) to the thermophotovoltaic cells (14).

Abstract: This invention relates to controlling a load-following solid oxide fuel cell system such that the fuel cells in the system are operating within an acceptable electrochemical reaction efficiency. The system has a controller that is programmed to detect a load change on a fuel cell stack, and when the load decreases, reduces the fuel flow rate to the stack or deactivates one or more fuel cells in the stack such that the stack operates within an acceptable electrochemical reaction efficiency range corresponding to the decreased load; and when the load increases, the controller increases the fuel flow rate to the stack or activates fuel cells in the stack such that the stack operates within the acceptable electrochemical reaction efficiency range.

Abstract: This invention relates to a tubular direct methanol fuel cell. The fuel cell includes: a tubular inner electrode, a tubular outer electrode located concentrically around the inner electrode, and an annular electrolyte conduit located concentric to and in between the inner and outer electrodes. The inside of the inner electrode is a reactant conduit that is fluidly communicable with a first reactant source such that a first reactant is transmittable therethrough. The outside surface of the outer electrode is fluidly communicable with a second reactant source such that a second reactant is transmittable over the outside surface of the outer electrode. The annular electrolyte conduit is fluidly communicable with a fluid electrolyte source such that a fluid electrolyte is transmittable therethrough. One reactant is methanol-containing fuel, and the other reactant is oxidant.