Exergy analysis of network systems at steady state

Abstract

Abstract The thermodynamic exergy concept is applied to the input-output flow analysis of network systems at steady state. Exergy versions of the concepts of throughflow, total system throughflow, path length and cycling index are introduced. The exergy version of total system throughflow for irreversible processes is always larger than that for reversible processes. Relationships between exergy path length for irreversible processes and that for reversible processes parallel relationships between path length due to exergy annihilation in a system and that due to exergy outflow to the environment. Relationships between exergy cycling index for irreversible processes and that for reversible processes parallel relationships between cycling index due to exergy annihilation in a system and that due to exergy outflow to the environment. Thus, is spite of the fact that entropy and exergy have opposite properties, it is shown that they manifest similar patterns for network laws. This paper and a previous one by the author provide, for the first time, the input-output flow analysis of networks dealing with non-conservative quantities.