Optimization of the TIEC/AMTEC cascade cell

Abstract

A mathematical modeling of a system consisting of a cascade of a thermionic energy conversion (TIEC) device and an alkali metal thermal to electric converter (AMTEC) device has been performed to optimize the efficiency of the cell. The TIEC is heated by electron bombardment, which converts heat partially into electricity and rejects the remaining. The AMTEC utilizes this reject heat of the TIEC. Cascading these two cells provides lots of advantages. A mathematical model of the cascade converter has been developed to analyze the effects of key parameters such as power level, heat fluxes, and temperatures. In this effort, a 12-node system of nonlinear simultaneous equations has been constmcted which is solved by MATHCAD and a locally optimized efficiency has been derived. Thus, efficiency of the cascaded cell is improved, so that it is greater than the highest efficiency among the TIEC and AMTEC and lower than the sum of their individual efficiencies. The results were compared with the previous program written for the same problem.