Performance analysis of proposed solar HDH water desalination systems for hot and humid climate cities

Transient performance analysis and investigation of three proposed solar powered humidification-dehumidification (HDH) water desalination systems: single stage (SS), double stages (DS) and modified double stages (MDS) systems are presented for hot and humid cities. Open/closed modes of operations of the systems are also investigated. A parametric study of the hourly and daily systems performance is presented at various operating parameters. The results reveal that: (i) inserting solar collectors in HDH systems for air and water heating substantially enhances the system's performance; (ii) the fresh water productivity of all systems at open mode of operation increases with increasing the outdoor air temperature and humidity; (iv) at low outdoor humidity, the system's performance at closed mode of operation is higher than those at open mode of operation and the opposite is true at high outdoor humidity; (v) comparing between the three systems, MDS system (open mode) can produce fresh water of 350 kg/day with GORday of 1.63 and its fresh water productivity enhances with 86.7% and 34% than SS and DS systems, respectively; and (vi) using control system, the performance of the proposed systems can be maximized by changing between the open/closed mode of operations according to the outdoor conditions.