THERMODYNAMIC PERFORMANCE OF SOLAR-POWERED IDEAL ABSORPTION CYCLES

The use of ideal absorption cycles with external heat transfer irrever sibilities to obtain the performance limits of solar-operated absorpti ons systems is considered in this paper. The absorption machine is rep resented by the three-heat-reservoir ideal cycle and it is supplied wi th energy from a solar collector-storage system. Analytical expression s are obtained for the coefficient of performance, the cooling capacit y, the entropy production and the second-law efficiency of the system. The results obtained for cycles with external heat transfer irreversi bilities and for fully reversible cycles are compared with those obtai ned by detailed simulation of the absorption machine. Externally irrev ersible cycles are found to give realistic upper limits to the cooling capacity and the coefficient of performance of solar-powered absorpti on cooling systems. (C) 1997 Published by Elsevier Science Ltd.