Power Generating Performance of Alkali Metal Thermoelectric Converter

Abstract

The alkali metal thermoelectric converter (AMTEC) utilizing the sodium ion conducting β″-alumina is a device to convert directly heat energy to electric energy. It is characterized by high conversion efficiencies, high power densities, no moving parts and low maintenance requirements. Because of these merits, AMTEC is one of the most promising candidate for aerospace power system, remote power station and dispersed small scale power station.
In this paper, the experimental results of the series connected cells and the theoretical considerations about internal resistances have been reported. For the single cell, the open voltage of 1.37V and the maximum power of 7.89W and maximum power density of 0.40W/cm² at the sodium temperature of 1, 077K have been obtained. For the series connected two cells, the open voltage of 2.60V and the maximum power of 12.3W at the sodium temperature of 1, 016K have been obtained. This power was about 90% of the sum power of two cells. This power decrease is due to the resistance of current collecting bus bar. It is necessary to optimize the current collecting bus bar considering the electrical resistance and heat conductance.