Optimal distribution of heat exchanger area for maximum efficient power of thermoelectric generators

Abstract

Based on the multi-element thermoelectric generator model established in the previous literature, finite-time thermodynamic theory is used to deduce the efficient power expression of the thermoelectric generator. For a fixed number of thermoelectric elements and total heat exchanger area, the maximum efficient power is obtained by optimizing heat exchangers area distribution and output current. The effects of the number of thermoelectric elements and the total heat exchanger area on the maximum efficient power are analyzed. The results show that there is an optimal heat exchangers area distribution and an optimal output current to maximize the efficient power of the thermoelectric generator. Thermal efficiency at maximum efficient power is always better than at maximum power output. The total heat exchanger area is increased from 0.03 m2 to 0.09 m2, the maximum efficient power is increased from 0.02 W to 0.26 W, and the corresponding optimal output current and optimal heat exchangers area distribution are increased by 138% and 6.7%, respectively. In the actual designing process of the thermoelectric generator, the influences of the number of thermoelectric elements, the total heat exchanger area, the output current and the heat exchangers area distribution on its performance should be considered.