The Journal of Science and Engineering Applications (JSEA)

Abstract

The shortage of potable water is the biggest problem of the world in this century because of 
the population growth and unsustainable water consumption rates.  About half of the world’s population in 
88 developing countries are affected by water crises which results in 80-90% of all diseases and 30% of all 
deaths. Since water shortage is directly related to poverty, low cost, especially solar, seawater desalination 
methods can help alleviate this trouble. 
In which present research, an experimental study was presented for a novel stepwise solar still 
accompanied by two units, a compound parabolic solar collector as a preheater and heat exchanger after 
condenser. A computer model has been developed, according to thermal energy balance equations to 
predict the transient performance of the system. The experimental in this study was achieved by 
constructing the test rig that verify the theoretical results by practically real field testing. 
Results achieved from this study demonstrate clearly the importance of rising the feed (saline water) 
temperature, increasing the condensation surface area and further heating of evaporation surface; Using 
new still absorber design, that increase the system productivity (91.3%) compared with the conventional 
solar still yield. This shows obviously that solar still output is affected largely by changing design 
parameters.