Optimum Solar-Powered HDH Desalination System for Semi-Isolated Communities

For semi-isolated communities, fresh water may be scarce; however, brackish water or seawater can be easily accessed. This provides a drive to develop optimum-cost desalination system for such communities. This paper presents the optimization of a water-heated solar-powered humidification-dehumidification (HDH) desalination system with variable saline water flow rate. The design variables include the sizing of solar collector, storage tank and its internal heat exchanger, humidifier and dehumidifier. A program was developed to predict performance based on selected weather data file and optimize the system for minimum unit cost of produced fresh water. System cost is predicted via different first-order estimators. A tailored optimization technique is used and compared to a genetic algorithm procedure in the design optimization for local climate and market. A case study develops an optimum desalination plant for the Red Sea near the city of Hurgada and compared to previously developed system.