What is Exergy

In the last decades an exergetic analysis became increasingly popular because this analysis identifies the location, magnitude and sources of thermodynamic inefficiencies. A conventional exergetic analysis, however, does not consider (a) the real potential for improving a system nor (b) the interactions among the components of the system. The interactions among different components of the same system can be estimated and the quality of the conclusions obtained from an exergetic evaluation can be improved, when the exergy destruction (irreversibilities) within each system component are split into endogenous/exogenous and avoidable/ unavoidable parts. We call this advanced exergetic analysis. The purpose of this chapter is to demonstrate that the advanced exergetic analysis is a practical method that allows engineers to extract useful information and conclusions and to develop ideas and solutions that cannot be suggested by other methods. In this chapter the conventional and advanced exergetic analysis are applied to an air refrigeration machine.