Solar energy is very useful in the process of desalination especially for areas that suffer from a
lack of clean water resources. In recent years, many people have been using solar still. Therefore
the raising of the productivity and efficiency of solar still represents the most important problems
that need further research. The present work aims to study the effect of preheating the water entering
to still and the effect of reducing pressure inside the still on the productivity of the solar
still. Therefore in present work two identical single basin typical double slope solar stills of the
inner basin dimensions for each still 2 m × 1 m × 0.08 m, have been designed and fabricated with
mild steel plate. One of them is conventional solar still and the other is modified with flat plate
collector and vacuum pump to study the effect of preheating and vacuum on the performance of
solar still. The experimental measurements are made to enhance the solar still productivity by
firstly preheating the water entering the still using flat plate collector and secondly by integrating
the still basin with vacuum pump. The results show that preheating the water entering the still increases
the water productivity by amount about 27.7% - 29.3%. The results also show that decreasing
pressure inside the still using vacuum pump improves the solar still water productivety
by amount about 21.8% - 23.9%. |
