On entropy generation in thermoelectric devices

In this paper, a comparison between the Entropy Generation Minimization met hod and the Power Maximization technique is presented. The assessment is pe rformed by analyzing, as a typical example of direct conversion heat engine s, the thermoelectric generator. The effects of heat-leak and finite-rate h eat transfer on the performance of the generator, which is modeled as a Car not-like engine with internal irreversibilities, are studied. Even though b oth methods lead to the same conclusions, the entropy generation minimizati on method, when applied for such an inherently irreversible device, is show n to be less straight forward than the power maximization technique requiri ng careful accounting of the different sources of irreversibility. Moreover , the entropy generation rate vs. efficiency behavior of the generator reve als that the efficiency at minimum entropy generation rate and the maximum efficiency are distinct. (C) 2000 Elsevier Science Ltd. All rights reserved .