Solar driven double-effect absorption cycles for sub-zero temperatures

Abstract

This paper presents a theoretical study of a solar driven double-effect absorption system with ammonia–lithium nitrate for sub-zero evaporation temperatures. The performance of a double-effect parallel flow ammonia based absorption system with lithium nitrate as absorbent is investigated. This includes the determination of the effect of the strong solution distribution on performance. A ratio of 0.65 appears to be the most advantageous. The paper also presents the dynamic performance of a double-effect ammonia–lithium nitrate absorption system driven by solar energy under Mediterranean summer conditions. The solar energy is obtained by horizontal N–S parabolic trough solar collectors because they can deliver high temperatures that are required to drive the double-effect absorption system. Simulations of the solar absorption systems with a hot storage are performed in order to supply the cooling load of a pork slaughterhouse with maximum cooling load of 600 kW.