Modeling of a conventional solar still with draft and humidification-dehumidification process

A conventional solar still equipped with a self sustainable humidification-dehumidification open air flow stream to enhance the system productivity was investigated. This modification maintained higher temperature difference between the saline water to be evaporated and the condensing surface. Accordingly, higher driving force for the evaporation-condensation processes was provided. This was achieved by insulating the condensing surface from the incoming radiation and by the continuous removal of the latent heat of condensation by the cooling water. Water production of 2.34 L/m².day was obtained by the modified solar still. Thermodynamic relations and mass and energy balances were utilized in modeling the operation of the system. The accuracy of the experimental results was validated against a linear model. Variations in the enormous parameters that influence solar studies limited the value of the coefficient of determination for the lumped efficiency of the system at 0.74. Factors that affected the still performance were highlighted, and recommendations for future improvements were made.