Contributing to the improvement of the production of solar still

Solar still can be considered as a promising desalination system to produce distilled water with quality good enough for drinking and irrigation in remote areas due to its simplified design, low maintenance, extended life time, and low capital cost. In addition, among the nonconventional methods to disinfect the polluted water, the solar distillation is considered as one of the most prominent methods. The productivity of the solar still is determined basically by the temperature of water in the basin and the glass temperature. Various active methods have been tested to increase the temperature of the basin, so as to improve the productivity of solar still. In this work, an energy storing material is used in the basin, a flat plate solar collector and a separate condenser are coupled with the solar still to increase the daily productivity by increasing the temperature of the water during the day and to store the hot water excess that would extend water desalination beyond sunset. The models of the different sections of the unit are developed from the governing heat and mass transfer equations. These models will be used for sizing the system. The numeric simulation with the developed models allows the study of the relation among the different control parameters of the unit that would evaluate its performance. An economic analysis was carried out, since it concerns the final cost of produced water, to determine both the cost of fresh water production and the payback period of an experimental setup.