Engineering topics

O'Connor, Dennis

Publications and source records attributed to O'Connor, Dennis.

4 records

NASA NTRS1994

Current-Collecting Grids For AMTEC Electrodes

Photodeposition or sputter deposition of refractory metal in grid pattern on solid electrolyte of alkali-metal thermoelectric converter (AMTEC) prior to deposition of electrode decreases electronic resistance and increases current and peak power of converter significantly. Concept also applicable to other devices that include electrically conductive, porous electrodes; such as solid-state fuel cells and solid-state electrolysis cells.

Ryan, Margaret A.↗

NASA NTRS1992

Thermal-To-Electric Converter With Greater Power Density

Proposed design for alkali-metal thermal-to-electric converter (AMTEC) incorporates refinements to increase power density and reduce input temperature below typical prior design. Converter has compact, planar configuration. Cells stacked densely with remote condenser for thermal efficiency and high power density. Either liquid- or vapor-fed cells utilized. Heat fed-in at lower temperature.

Williams, Roger M.↗

NASA NTRS1991

AMTEC cell testing, optimization of rhodium/tungsten electrodes, and tests of other components

Electrodes, current collectors, ceramic to metal braze seals, and metallic components exposed to the high 'hot side' temperatures and sodium liquid and vapor environment have been tested and evaluated in laboratory cells running for hundreds of hours at 1100-1200 K. Rhodium/tungsten electrodes have been selected as the optimum electrodes based on performance parameters and durability. Current collectors have been evaluated under simulated and actual operating conditions. The microscopic effects of metal migration between electrode and current collector alloys as well as their thermal and electrical properties determined the suitability of current collector and lead materials. Braze seals suitable for long term application to AMTEC devices are being developed.

Williams, Roger M.↗

NASA NTRS1991

Performance projections of alternative AMTEC systems and devices

The alkali metal thermoelectric converted (AMTEC) converts heat to electrical power without moving parts. Attention is presently given to two AMTEC devices that have been optimized for conversion efficiencies of the order of 30 percent or more at 1100 K, in conjunction with high volumetric power densities. A 'tube-bundle' AMTEC configuration yields a peak power of 426 W/l; a flat-plate AMTEC system yields 2.4 W/l.

Underwood, Mark L.↗