Performance analysis of alkali metal thermoelectric converter and segmented thermoelectric generator hybrid system based on a comprehensive model

Abstract The conceptual hybrid system combined alkali metal thermoelectric converter (AMTEC) and segmented thermoelectric generator (STEG) is a promising static thermal to electric conversion system. A comprehensive model and an effective iterative numerical solution method for the AMTEC/STEG hybrid system have been developed in this paper. The comprehensive model includes the AMTEC unit model and the STEG unit model. The good agreement between the model calculation results and those provided in the published reference show the correctness and accuracy of the models. The effect of beta’’ alumina solid electrolyte (BASE) temperature and condenser temperature on the system performance, the load following characteristic and nominal operation conditions have been investigated using the comprehensive model in this paper. According to the performance analysis results, 1173 K and 653 K are selected as BASE and condenser temperatures. When system input power is 249 kW, the peak conversion efficiency can reach 34.2%. The nominal operation point has been selected according to the optimal performance parameters and load following characteristic of the hybrid system, at the nominal operation point, the system electric power, conversion efficiency, current and voltage of AMTEC and STEG can reach 84 kW, 34.2%, 165.5 A, 448.3 V, 51.7 A, 356.5 V, respectively.