Graphical exergy study on single stage absorption heat transformer

Abstract

A single stage absorption heat transformer (SAHT) is analyzed with the aid of a graphical exergy methodology based on energy-utilization diagrams (EUDs). This analysis provides detailed information on internal phenomena such as the driving forces and the distribution of the exergy loss in each subsystem. Two cases with different flow ratios are investigated. They show that the exergy loss in the premixing process in the absorber is very large. To reduce that exergy loss, a multiple-compartment absorber in close-to-equilibrium operation is proposed. This scheme can give high temperature for useful heat even when a low flow ratio is applied.