IMPROVED OSC AMTEC GENERATOR DESIGN TO MEET GOALS OF JPL'S CANDIDATE EUROPA ORBITER MISSION

摘要

The preceding paper described OSC's initial designs of 'AMTEC power systems, consisting of one or two generators, each with 2, 3, or 4 General Purpose Heat Source (GPHS) modules and with 16 refractory AMTEC cells containing 5 Beta Alumina Solid Electrolyte (BASE) tubes; and presented the effect of heat input and voltage output on the generator's BOM evaporator and clad temperatures and on its EOM system efficiency and power output. Comparison of the computed results with JPL's tentative goals for the Europa Orbiter mission showed that all of the initial 16-cell design options yielded either excessive evaporator and clad temperatures or insufficient EOM power to satisfy those mission goals. The present paper describes modified OSC generator designs with different numbers of AMTEC cells, cell diameters, cell lengths, cell materials, BASE tube lengths, and number of tubes per cell These efforts succeeded in identifying generator designs with only half the number of AMTEC cells which - for the same assumptions - can produce EOM power outputs substantially in excess of JPL's goals for NASA's Europa Orbiter mission while operating well below the prescribed BOM limits on evaporator and clad temperature; and revealed that lowering the emissivity of the generator's housing to raise the cells' condenser temperatures can achieve substantial additional performance improvement. Finally, the report culminates in programmatic recommendations.