This study investigates the applicability of the method using an entropy balance by the Second Law of Thermodynam- ics to analyze and design thermal systems. The entropy method determines thermodynamic effectiveness of components by quantitative assessment of the irreversibilities associated with the processes involved. The entropy balance method has been used to analyze an absorption system of single stage chiller, a single and a double stage heat transformer with Lithium Bromide-Water as the working fluid.

The entropy method yields not only the same information as is conveyed by the methods of energy and exergy analysis, it also predicts clearly the influence of irreversibilities of individual components on the coefficient of performance and its effectiveness, based on the process properties, rather than on ambient conditions. Furthermore, this method is capable of presenting the overall distribution of the heat input by displaying the additional heat required to overcome irreversibility of each component without ambigui- A computer simulation code program for absorption systems has been developed, which makes it possible to model the systems and evaluate the performance of the systems with the methods of energy, exergy and entropy.