Experimental study and economic evaluation of various techniques for increasing fresh water production in a cascade solar water desalination unit

In this paper, a cascade solar desalination unit with external reflector designed and built and experimented in eigth days. In order to increase the production of fresh water, various techniques were applied such as 1) installing a number of finns on the stairs and on the waterway to create hot spots as a new idea, 2) use of internal reflectors at the base of the stairs and 3) use of an external condenser for increasing condensation rate of produced vapor. Then, the under study system was experimented in eight configuration using combination of above techniques and the experimental results were presented as well as the results of economical analysis. The results showed use of the finns led to the most amount of fresh water although the rest of techniques significantly increased the product. It is worth mentioning that use of the finnes led to fresh water with the lowest cost of product in value of 1343.1 Rials/lit. On the other hand, the system with an external condenser had the maximum efficiency and the system with the finns has the third place among the eight study configuration.