DESIGN AND APPLICATIONS OF CLOSE-SPACED THERMIONIC CONVERTERS WITH NOVEL ISOTHERMAL ELECTRODES

IT WILL BE DEMONSTRATED IN PHASE I BY ANALYSIS AND EXPERIMENT THAT ELECTRODES FOR THERMIONIC CONVERTERS HAVING HEAT PIPES INCORPORATED IN THE ELECTRODE STRUCTURE ACCOMMODATE HIGH INTERELECTRODE HEAT FLUX WITHOUT DISTORTION. THESE RESULTS WILL ENABLE CLOSE-SPACED CONVERTERS WITH ELECTRODE GAPS OF 5 UM OR SMALLER. SUCH A CONVERTER CAN BE 13% EFFICIENT WITH AN EMITTER TEMPERATURE OF ONLY 1300 K. THIS IS A NEW APPROACH TO ENHANCED ENERGY CONVERSION EFFICIENCY WHICH CAN SIGNIFICANTLY INCREASE OVERALL EFFICIENCY OF POWER GENERATION AT COMPETITIVE COST. THE ANALYSIS OF THE ELECTRODES WILL CONSIDER HEAT TRANSFER, MECHANICAL DEFORMATION, AND THERMIONIC PERFORMANCE. TRADE-OFF OF HEAT FLUX AND PHYSICAL DIMENSIONS WILL LEAD TO AN OPTIMUM DESIGN. EXPERIMENTS WILL USE LASER INTERFEROMETRY TO CHARACTERIZE AND CONFIRM THE CAPABILITIES OF THE ISOTHERMAL ELECTRODE. AN APPLICATION STUDY WILL QUANTIFY THE COMMERCIAL BENEFITS THAT CAN REASONABLY BE EXPECTED FROM THIS IMPROVED PERFORMANCE, WHICH CAN BE COMMERCIALIZED IN THIS DECADE. FOLLOW-ON WORK WOULD INCLUDE FABRICATION OF AN OPERATING MODULE OF CLOSE-SPACED THERMIONIC CONVERTERS WITH THE ISOTHERMAL ELECTRODES.