Performance analysis of a novel solar desalination system – Part 2: The unit with sensible energy storage with thermal insulation and cooling system

Abstract

Solar assisted desalination systems have an unequivocal potential to meet water demand with their eco-friendly, sustainable and low cost features in the face of the decrease in water resources and increasing costs worldwide. In this context, a wide range of design aspects have been considered so far in literature aiming at enhancing current performance figures of solar still systems notably water productivity. In the first step of this research, such an attempt has been done to devise and construct a novel domestic solar still unit integrated with sensible heat storage and booster reflector. Thermal performance of the first design has been extensively evaluated through outdoor tests, and the water productivity figures have been noted for different sky conditions. Within the scope of the present study, previous design is extended to some structural and operational modifications, and the enhancement in performance figures is discussed. A temperature-controlled low-cost water spray cooling system is integrated to the aperture glazing of the unit to expedite the evaporation–condensation process, and the body is externally insulated except aperture glazing to reduce heat losses and maximise the thermal energy content of saline water in the system during the desalination period. The results reveal that compared to the findings of the previous study; average efficiency of water productivity is improved by 112.7% with 1.34 l/m2day. In this study, the thermal efficiency of the system is determined to be 21.37%. It is also achieved from the findings that further enhancements in water productivity can be achieved if the slope angle of aperture glazing is optimised.