Parametric study on a vertical multiple-effect diffusion-typesolar still coupled with a heat-pipe solar collector

A parametric investigation was theoretically performed for the vertical multiple-effect diffusion-type solar still, which consists of a number of vertical partitions in contact with saline-soaked wicks with narrow gaps between the partitions, coupled with a heat-pipe solar collector. The proposed still has some advantages: the still's size is compact, the still can produce distilled water without electricity, and the productivity is greater than that of conventional multiple-effect diffusion-type solar stills. We theoretically predicted the optimum angle of the solar collector on the spring and autumn equinox and the summer and winter solstice days, and also performed parametric investigations of the design and operation conditions; it was found that productivity increased with an increase in the number of partitions and the temperature of the saline water fed to the wicks, and with a decrease in the ratio of the solar collector area to each partition area, the thickness of the diffusion gaps between partitions, and the feeding rate of saline water to the wicks.