IMPROVED ENERGY EFFICIENCY IN ABSORPTION HEAT-PUMP THROUGH PROCESS MODIFICATION - PART II - THERMODYNAMIC POTENTIAL OF LIQUID-LIQUID-EXTRACTION OF AMMONIA-WATER MIXTURES

Extraction-system-attached (ESA) ammonia-water absorption heat pumps w ere derived from the conventional system as a strategy to improve the energy efficiency of the conventional ammonia-water absorption heat pu mp. The ESA absorption heal pumps were obtained by attaching a liquid- liquid extraction unit in the conventional system. Theoretical thermod ynamic simulation of the ESA and conventional ammonia-water absorption heat pumps showed that a higher COP and less irreversibility occur wh en the ammonia-water mixture is separated by the liquid extraction pro cess instead of the non-isothermal process used in the conventional sy stem. The ESA systems employing nitrobenzene as the extraction solvent gave the highest COP and the lowest irreversibility. (C) 1998 Publish ed by Elsevier Science Ltd. All rights reserved.