Application and discussion on entransy analysis of ammonia/salt absorption heat pump systems

Abstract

Abstract This study investigates the application of the entransy analysis in ammonia/salt absorption heat pump (AHP) systems. The results of the entransy analysis are compared with those of energy analysis and exergy analysis under typical and various operating conditions. Entransy dissipation and exergy loss in each component, as well as coefficient of performance (COP), exergy efficiency and entransy efficiency of systems, are discussed. The changing trends of entransy dissipation in each component are similar under various operating conditions. However, the entransy analysis performs better than the exergy analysis in evaluating the irreversible loss of each component. Moreover, the differences between the exergy analysis and entransy analysis are mainly in absorber, generator and SHE. Especially in the NH3/NaSCN system, the proportion of entransy dissipation in generator is 60.8%, which is almost twice of the proportion of exergy loss (34.9%). In addition, under various operating conditions, entransy efficiency and COP have roughly the same changing trend. Meanwhile, entransy efficiency is more reasonable than exergy efficiency in evaluating the performance of systems under the absorption temperature, which varies from 30°C to 50°C. These comparison results demonstrate that the entransy analysis is appropriate to evaluate the performance of ammonia/salt AHP systems and suitable for analyzing the irreversibility of each component.