Structural design and optimization of two segmented asymmetrical thermoelectric generator for heat pipe cooled reactor application

Abstract

As deep space and deep sea exploration continues, the requirements for energy systems are constantly increasing. Small reactors, with their high endurance, high reliability and high energy density, are ideal choices. The heat pipe reactor, as a small nuclear reactor with great potential, has received widespread attention from the academic community. Thermoelectric generators (TEG) are commonly used thermalto-electric energy conversion devices in heat pipe reactors and play an important role in static energy conversion. This study employs COMSOL Multiphysics software to conduct finite element simulation analysis on TEG, comprehensively considering factors such as contact resistance, contact thermal resistance, and external resistance that affect TEG performance. The relationship between the leg shape and the thermoelectric power generation performance of two segmented inverted circular truncated cone and circular-X TEG are analyzed and the key factors affecting their thermoelectric conversion performance are summarized. In terms of stress analysis, both types can shift the stress from hot end to cold end, to adapt to the welding process. For two segmented inverted circular truncated cone TEG, when the ratio of the max and min cross-sections is 0.83, it can cause a decrease in thermal stress on the interfaces with few efficiency decrease. For two segmented circular-X TEG, their efficiency increases monotonically as the minimum cross-sectional radius decreases. When the ratio of the max and min cross-sections is 0.83, both the conversion efficiency and the stability of the working state are improved.