Abstract:
Safe water supply is not universal, thus a huge gape exists between the availability and consumption rates of clean water, leading to an abnormal water scarcity and health disasters. The possible solution to balance this supply demand rate is sea water desalination. Main challenge is to efficiently harness the enormous potential of sea water with cost effective technology. To meet the ever increasing demands of fresh water, humidification dehumidification water desalination system (HDH) driven by the cheapest solar energy is a promising technology. To enhance the thermal efficiency the system comprises of independent components for all functions like heating, evaporation and condensation.
In this research, different HDH water desalination systems are modelled and analyzed using TRNSYS and performances are compared. Parametric optimization is done and the productivity is improved by using a rotary desiccant dehumidifier and increasing the humidification rate. The Asian metronome weather file was used for initial air properties and radiation data. The heating fluid water is circulated through the system in an open air open water cycle and the simulations results showed that water temperature from the collector outlet depends on the global solar radiations and temperature and flow rate of the inlet feed water. Preheating the feed water up to 10°C significantly increased the output. Collector type and area are also one of the important factors that affect the productivity. Evacuated tube collector of 1m2 area produced more condensate per hour as compared to flat plate collector of 1.5m2 area. The productivity was significantly increased using the rotary desiccant dehumidifier and more than 8kg/hr fresh water condensate was produced.
