الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
The present work deals with studying and modeling of solar stills. The basic idea of the work is to check the production of a simple still for solar distillation (desalination) that has no moving parts and does not use any other source of energy. The still is basically a rectangular basin filled with black or blackened solid material that acts as the solar energy collector. Experiments were carried out during the months from May to August. The different materials used as collecting media are black plastic balls made of polyamide with different diameters, steel balls painted black and black or dark gravel. The experiments investigated the effect of changing initial water volume, water to ball volumetric ratio and black solid material diameters on the productivity and the efficiency of the still. The highest volume of distillate water was obtained with 4mm diameter plastic balls, and water to ball ratio 1.8, this rate was 4 m³/m² day with an average efficiency of 49%. It was also found that solids with high heat c2p3city gives better rates of distillation and higher efficiency in the after noon hours, A mathematical model \vas developed and used to predict the performance of the still. It was found that the predicted results are in good agreement with the experimental results. The percentage deviation is less than 10% of glass, water and solid temperature for all types of solids. And less than 20% for volume of water collected for experiment with spherical solid. But with gravel which has non uniform shape, a correction factor must be included in the model. Finally the still was used for desalination of sea water and give almost the same rate of production at the best conditions.