Vertical Single-Effect Diffusion Solar Still Coupled with a Tilted Wick Still: An Experimental Study

A single-effect diffusion still, instead of a multiple-effect diffusion (MED) still, combined with a tilted wick (TW) still was investigated experimentally under actual weather conditions to investigate whether the natural convection can transport the vapor from the TW still to an MED still adequately. It was found that the single-effect still can be heated by vapor from the TW still and solar radiation absorbed on the single-effect still. From the experiments in summer and autumn, it was found that a MED still can be heated in both seasons whether the MED still absorbs solar radiation directly or not. The experimental results agreed with the calculation results. The total daily amount of distillate, Σmd,total, did not correlate with the daily horizontal solar radiation, ΣGday, but strongly correlated with daily solar radiation incident on the still, ΣGstill. The maximum of Σmd,total obtained in experiments was about 4.88 kg/m day when ΣGday and ΣGstill were 13.6 and 18.4 MJ/m day, respectively