Abstract: Our cylindrical TPV generator uses low bandgap PV cells mounted on circuits in a polygonal array around an IR emitter. The combustion gases are completely contained within the radiant tube burner. The PV array is mounted inside a leak-tight envelope cooled on its outer surface by either water or air flow. Flanges on either end of this PV array container allow for hermetic seals. A folded back coaxial emitter support tube provides a long path length limiting thermal conduction along its cylindrical wall from the very hot emitter section to the cooled seal flange. In our improved cylindrical TPV generator, we provide for a low temperature catalytic after-burn by providing a perforated turnaround plate coupling between the inner disk stack and the outer disk stack. This perforated turnaround plate provides a small amount of combustion air for the after-burn. A catalyst coating can be provided on the hotter surface of the outer finned disks. The after-burn occurs in the outer finned disk stack.

Abstract: Our cylindrical TPV generator uses low bandgap PV cells mounted on circuits in a polygonal array around an IR emitter. The combustion gases are completely contained within the radiant tube burner. The PV array is mounted inside a leak-tight envelope cooled on its outer surface by either water or air flow. Flanges on either end of this PV array container allow for hermetic seals. A folded back coaxial emitter support tube provides a long path length limiting thermal conduction along its cylindrical wall from the very hot emitter section to the cooled seal flange. In our improved cylindrical TPV generator, we provide for a low temperature catalytic after-burn by providing a perforated turnaround plate coupling between the inner disk stack and the outer disk stack. This perforated turnaround plate provides a small amount of combustion air for the after-burn. A catalyst coating can be provided on the hotter surface of the outer finned disks. The after-burn occurs in the outer finned disk stack.

Abstract: A hydrocarbon thermophotovoltaic (TPV)electric generator insert has applications as a replacement burner to retrofit existing appliances. The retrofitted appliance is thus upgraded to either a cogeneration or self-powered unit. The design of the TPV burner insert is independent of the appliance to be retrofitted except for external adapters and can be easily retrofitted to any appliance design requiring a hydrocarbon burner. The burner uses fully premixed air and fuel near stoichiometry to attain a short duration, high intensity burn through optically dense porous ceramic emitters. The emitters attain temperatures between 1300° and 1500° C. The infrared radiation is collected by low bandgap photovoltaic cells with optical response at least out to a wavelength of 1.7 micrometers such as GaSb cells to produce DC power. The circuit cooling system uses fans or circulating water for cooling.

Abstract: A shingle circuit array and a method of assembling the shingle circuit is provided. The array has a shingle circuit with a substrate, an insulation film layer, a metal layer and TPV cells connected to the metal layer in series forming a shingle pattern with terraces. The substrate is of CTE matched material. The metal layer may be copper pads deposited on the terraces. The TPV cells are bonded to the copper pads and may be GaSb cells. Substrate materials include AlSiC or a Cu/Invar/Cu laminate sheet. The AlSiC material may be a microstructure having a continuous Al-metal phase with a discrete SiC particulate phase. The substrate may also be an enameled cast-iron substrate. The shingle circuit array may be provided in a TPV generator.

Abstract: The present invention is a hydrocarbon fired thermophotovoltaic furnace having a non-fused silica tube. In a preferred embodiment, the furnace has an infrared emitter tube having a top end and a bottom end and a substantially transparent non-fused silica window tube having a closed top end. The window tube is positioned concentrically around the infrared emitter tube, and the infrared emitter tube is in fluid communication with the window tube. The window tube is preferably composed of Lucalox (alumina or Chromolux), magnesia, yterria, titania, spinel, stablized zirconia or yterria alumina garnet. In another preferred embodiment, the furnace has a radiator tube having a top end and a bottom end and an infrared emitter tube having a closed top end. The infrared emitter tube is positioned concentrically around the radiator tube, and the radiator tube is in fluid communication with the infrared emitter tube. Fluid flows from the inner tube to the outer tube.

Abstract: Thermophotovoltaic (TPV) electric power generators have emitters with infrared (IR) outputs matched with usable wavelengths for converter cells. The emitters have durable substrates, optional refractory isolating layers, conductive refractory metal or inter-metallic emitter layers, and refractory metal oxide antireflection layers. SiC substrates have tungsten or TaSi2 emitter layers and 0.14 micron HfO2, ZrO2, Al2O3, Ta2O5 and TiO2 antireflection layers used as IR emitters for GaSb converter cells in TPV generators.

Abstract: A shingle circuit array and a method of assembling the shingle circuit is provided. The array has a shingle circuit with a substrate, an insulation film layer, a metal layer and TPV cells connected to the metal layer in series forming a shingle pattern with terraces. The substrate is of CTE matched material. The metal layer may be copper pads deposited on the terraces. The TPV cells are bonded to the copper pads and may be GaSb cells. Examples of substrate materials include AlSiC or a Cu/Invar/Cu laminate sheet. The AlSiC material may be a microstructure having a continuous Al-metal phase with a discrete SiC particulate phase. The shingle circuit array may be provided in a TPV generator.

Abstract: A small and light cylindrical thermophotovoltaic generator uses gaseous fuels, a counter flow heat exchanger, regenerator and low bandgap photovoltaic cells. In the fuel injection system, with preheated air from a recuperator, fuel combustion begins immediately when the fuel and air first meet. A hot and compact burn results from complete and rapid fuel and air mixing. A venturi necks down the air flow, and a chemically etched jet shim disk creates over 150 small fuel jet streams. The emitter geometric configuration provides good hot gas energy transfer to the IR emitter. Four alternate emitter configurations accomplish the good heat transfer. One emitter is a composite SiC with integrally formed internal fins which extend into the combustion chamber. The photovoltaic converter assembly has good spectral control, good high rate but lightweight heat removal and high current-carrying capability, while maintaining low parasitic IR absorption.

Abstract: A thermophotovoltaic generator apparatus includes a thermophotovoltaic converter assembly and a cooling fan positioned beneath the assembly for generating an updraft around the assembly. A fuel source is connected to the converter assembly by a fuel line. A new control system, which may include a non-metallic electrode for flame sensing and, regulates flow of fuel from the fuel source to the converter assembly. A housing encloses the cooling fan and the converter assembly. The converter assembly includes a fuel injector cup having a fuel inlet connected to the fuel source and a fuel outlet. A combustion chamber is positioned above the cup for receiving fuel from the fuel outlet and for allowing hydrocarbon combustion. A combustion fan is positioned between the cup and the cooling fan for generating an updraft into the combustion chamber. An infrared emitter is positioned around the combustion chamber for emitting infrared radiation when heated by combustion gases resulting from the hydrocarbon combustion.

Abstract: A hydrocarbon fired room heater with thermophotovoltaic electric generator has high power outputs without cell overheating and failure. The unit includes a burner for generating a hydrocarbon flame, a catalytic emitter positioned in the hydrocarbon flame for emitting infrared radiation when heated by the flame, a receiver positioned around the catalytic emitter for receiving the infrared radiation and for converting the infrared radiation to electric power, an exhaust chimney positioned adjacent the receiver, and air draw ducts having uncovered tops, upper parts, and lower parts and positioned adjacent the chimney and the receiver for directing heat up and away from the receiver. The chimney is positioned directly above the top edge of the receiver, and the air draw ducts are positioned adjacent the receiver and chimney for defining air draw channels. Each air draw duct is a generally U-shaped member having a pair of side walls and a boundary wall extending between the side walls.

Abstract: A thermophotovoltaic generator provides a greater power output while maintaining a compact, simplistic structure. The generator includes a burner having adjustable fuel and air flows, an infrared radiation emitter suspended above the flame nozzle of the burner and a cylindrical receiver surrounding the emitter. The emitter is a conical infrared emitter connected to the burner by wires. The emitter is positioned above the burner nozzle such that the emitter is immersed in the generated hydrocarbon flame. The emitter material catalyzes combustion on its surface. Infrared energy radiated by the heated emitter is collected by a cylindrical receiver that completely encircles the emitter. The receiver includes a flexible circuit having an inner surface, an outer surface, opposite ends, top and bottom edges and bending regions. First and second rows of low bandgap cells are connected to the top and bottom edges of the circuit, respectively, away from the bending regions.

Abstract: In the present invention, a thermophotovoltaic electric power generator is described. It contains low bandgap photovoltaic cells sensitive in the infrared out to at least 1.7 microns and a broadband infrared emitter with a shortpass IR filter located between the cells and the emitter to recycle the nonuseful IR back to the emitter. Several specific IR filter designs as well as filter/cell and filter/emitter combinations are described all of which improve the overall generator conversion efficiency.