Introduction of Exergy Concepts Using Intuitive Methods

Abstract

Exergy or availability concepts in steady flow are presented in an intuitive manner through use of physical models and accompanying property diagrams. The concept of exergy is explained through the use of reversible steady flow shaft work. The Gouy -Stodola theorem is proven and the processes illustrated using property diagrams. Finally, a comparison is made of the Carnot cycle operated as an engine, as a refrigerator and as a heat pump and exergetic efficiencies are shown for each. The exergetic and energetic Sankey balance diagrams for each of the three cycles are combined and compared to show the similarities and differences in the use of the exergetic method.

The maximum cooling density of a realistic Stirling refrigerator

“…The influence of finite-rate heat transfer and regenerative losses on the performance of a Stirling refrigerator for an ideal or Van der Waals gas as the working substance was investigated by Chen and Yan [16]. Petrescu et al [17] have published an analysis including the combined effects of heat and work irreversibility.…”