Fabrication and Performance Analysis of an Improved Solar Still

摘要

In this paper, a detail comparison of the design, fabrication, cost and water production analysis between an oldTubular Solar Still (TSS) and improved (new) one is presented. Since the cover material, a vinyl chloride sheet,of the old TSS was a little bit heavy, expensive and cannot be formed into a desirable size easily, a highly durablepolythene filmwas adopted as the cover of the new TSS. The newTSS ismade of cheap and locally acquisitionedlightweightmaterials. Consequently, the weight and cost of the new TSS were noticeably reduced and the durabilitywas distinctly increased. A few field experiments on the new TSS were carried out in Fukui (Japan) andMuscat (Oman) and the observed results are compared with the old one. The water production flux is proportionalto the temperature difference inside the still. Evaporation mass transfer coefficients (MTCs) and heattransfer coefficients (HTCs) are higher than those of condensation. Convection HTCs are much lower thanthose of evaporation/condensation. Finally, a linear relation is newly found between the total HTCs and MTCs.