A FALLACIOUS ARGUMENT IN THE FINITE-TIME THERMODYNAMICS CONCEPT OF ENDOREVERSIBILITY

Finite time thermodynamics is a well established field of applied ther modynamics. The key assumption of this approach is the validity of the concept of endoreversibility. In this article, a hypothesis is formul ated, and subsequently formally proved, that this concept rests on a f allacious argument. The concept of endoreversibility is inherently inc onsistent with the postulated set of assumptions because the internal reversibility of a thermal system appears to be contradictory to an ex istence of external finite area heat exchangers that communicate with the endoreversible internal part across the finite temperature gaps. T he irreversibilities contributed by the system components are inherent ly interconnected. As a consequence, the maximum power efficiency betw een the given temperature levels T-L and T-H>T-L, as predicted by fini te time thermodynamics assuming that the heat input into the system is free to vary, i.e., 1-(T-L/T-H)(1/2) is incorrect. In addition, the m agnitude of this figure of merit may be even smaller compared to the e fficiency of a real system. (C) 1998 American Institute of Physics.