Performance enhancement in hybrid static power generation by AMTEC–TEG systems: Energy, exergy, and interactions analyses and optimizations

Abstract

Alkali metal thermal electric converter (AMTEC) and thermoelectric generator (TEG) are two static energy conversion devices with attractive attributes including high scalability and the ability to utilize renewable energy sources. The present study analytically simulates and optimizes the performance of a novel hybrid AMTEC–TEG system from energy and exergy perspectives. The study scrutinizes interactions between the two devices, exergy destruction sources, solutions toward enhancing exergy efficiency, and the impacts of the heat sink, not accomplished in the open literature. The results reveal that exergy loss within the AMTEC condenser is the main source of exergy destruction; nonetheless, there exists a number of optimal designs by which the TEG can effectively recover this lost exergy. Also, the results show that a simple fin-fan or a passive heat exchanger can be sufficient for cooling the hybrid system while protecting the hybrid system’s valuable features like static and maintenance-free operation. The maximum values of energy and exergy efficiencies and generated power, attained within an improved load-following range for the hybrid system, are respectively 35.6%, 47.8%, and 8136 W. Furthermore, comparisons with similar systems acknowledge the superiority of the proposed hybrid system. Overall, the hybrid system is seen to be of high potential as a flexible, modular, static power generation system whose advantages are thoroughly discussed alongside its weaknesses, providing beneficial information for future studies.