Modeling and Energy Analysis of Stepped-configuration Thermoelectric Generator System - - Transient modeling and performance analysis

Aiming at the poor performance of the traditional thermoelectric generator system, a stepped-configuration thermoelectric generator system coupling high-temperature and low-temperature thermoelectric devices is proposed. A transient model considering non-uniform temperature distribution is established to explore the influence of the filling factor on the performance and the energy flow distribution characteristics within the system. The results show that the heat exchanger efficiency monotonically increases with the filling factor, and the conversion efficiency and system efficiency have maximum values with the change of the filling factor. The maximum conversion efficiency and system efficiency are 5.81% and 1.93% respectively. The input flow rate emerges as the dominant factor governing energy distribution. After conducting large-scale system design, the maximum system efficiency is 3.26%, and the exhaust heat fraction is 14.8%. These results demonstrate that system upscaling effectively mitigates significant heat losses through exhaust.