HD desalination by heat rejected from solar cooling systems

The paper reports the results of a performance analysis of an integrated cooling-desalination system driven by solar energy. In typical solar cooling plants, solar energy is used to drive absorption chillers providing cooling energy. Due to relatively low COP values, a large amount of heat is rejected from the chiller at low temperature. Such low grade heat can be properly used to drive a low temperature HD (Humidification-Dehumidification) desalinator. Two simulation procedures have been developed to model the absorption chiller and the HD desalinator under design and off-design conditions. By using such codes, the performance of the system has been investigated for a 50 kW cooling capacity, by varying temperature and mass flow rate of the sea water. Such procedures have been also included within TRNSYS environment to perform a transient simulation of the system, composed by a lithium-bromide absorption chiller, a solar collector field, an hot storage tank and an HD desalination unit. The plant off-design simulation has been carried out for typical meteorological conditions of Southern Italy, with ambient temperature and solar radiation variations, on a daily base.