Thermodynamic analysis of a sorption refrigeration system with and without internal heat recovery

Abstract

Results obtained from thermodynamic analysis of a solid sorption refrigeration system with and without internal heat recovery (IHR) employing ammonia as the refrigerant are presented. Four combinations of salts, namely MgCl2/SrCl2, MgCl2/CaCl2, CaCl2/SrCl2 and CaCl2/CaCl2, are studied for systems with internal recovery. The system chosen is the one that can produce ice at 2108C using a waste heat source available at 613 K. Energy and entropy balance equations are applied to analyse each of the processes to estimate the individual heat transfer and entropy generation rates for all the systems. Effects of the sorbent and reactor mass are duly considered. Results show that among the four combinations studied, CaCl2/CaCl2 cycle yields the highest coefficient of performance and specific cooling output per kilogram of the salt. Cooling/heating of the generator/absorber results in significant entropy generation in all the systems. IHR improves the performance significantly.