Intergration of Seawater Desalination in a Solar Heat Transformer: Analysis by the First and Second Law of Thermodynamics

Abstract

In this paper, an attempt has been made to study the combination: flat plate solar collectors, a single effect heat transformer and desalination system used to provide a seaside house with drinking water. Mathematical models of the solar flat plate collectors (FPC), absorption heat transformer (AHT) operating with the H2O-LiBr solution and the overall desalination system (WP) were developed to simulate the performance of this combination system. The energy and exergy analysis is carried out for each component of the system. All exergy losses that exist in this solar desalination system are calculated. Energy and exergy efficiencies are estimated.The energy efficiency of WP is higher then that for FPC and AHT. An acceptable thermal efficiency of 0.62 is obtained. From the view point of energy the combination FPC-AHT for desalination is an interesting system. Considering the overall desalination plant, the FPC is the component in which the highest exergy loss is generated.Exergetic efficiency of AHT increases slightly with an increase in the time of day. The daily exergetic efficiency of WP is higher then that for FPC and lower than that for AHT. An average value of exergetic efficiency of WP is 0.124. This small value of the exergetic efficiency of FPC is due to the important amount of exergy destructed in FPC. From the view point of exergy analysis and excluding the effect of exergy destructed in the FPC the combination FPC-AHT for desalination is an interesting system.