ENTROPY PRODUCTION ANALYSIS AND EXPERIMENTAL CONFIRMATION OF ABSORPTION SYSTEMS

Absorption chillers, heat pumps and heat transformers exploit thermal power input to satisfy a variety of refrigeration and heating applicat ions, as well as to boost the temperature of low-grade heat. Can one a rrive at accurate predictions of system performance with a simple anal ytic irreversible thermodynamic model? In capturing the essential phys ics of the problem, that model would be required to provide a predicti ve and diagnostic tool and to permit determination of optimal absorpti on system operating conditions. We derive such a model and check its v alidity against experimental data and computer simulation results from a variety of commercial absorption units. We reinforce the observatio n that commercial units appear to have evolved empirically such that m aximum efficiency is realized under design conditions. The failure of a host of previously-published endo-reversible thermodynamic models to account for fundamental qualitative features and accurate predictions of system behavior is documented with computer simulation results and experimental performance data. (C) 1997 Elsevier Science Ltd and IIR.