A COMPARATIVE THERMODYNAMIC STUDY OF SORPTION SYSTEMS - 2ND LAW ANALYSIS

As a consequence of the phasing out of CFCs, sorption systems appear t o be potential candidates to replace vapour compression systems, Among st sorption systems there exists a choice between several systems, suc h as liquid absorption, solid adsorption and chemical reaction heat pu mps. Nevertheless, few comparative studies between these systems have been undertaken so far. It is the aim of this paper to present such a study based on combined first and second law thermodynamical analysis of the different cycles. Simple entropy generation processes explain w hy the basic cycles for these systems yield performances much lower th an the Carnot efficiency. The possibility of operating regenerative cy cles with internal heat recovery and higher efficiencies has also been considered for typical common base conditions. Different entropy gene ration considerations have been visualised, such as thermal coupling ( external/internal), non-uniform temperature component entropy producti on and other irreversible processes for the COP degradation in these s ystems, It is found that thermal coupling irreversibilities in solid s orption systems and other internal irreversibilities in liquid sorptio n systems with solution heat exchanger are dominant in the actual COP degradation with respect to the reversible Carnot COP. Copyright (C) 1 996 Elsevier Science Ltd and IIR