Measured Performances of an Augmented [Double-Exposure Absorber-Plate] Single-Slope Solar Still
Abstract
Comparative measured performances of a double-exposure absorber-plate single-slope solar still and the conventional single-exposure solar still are reported. The single-slope basin-type solar still (SSBSS) is modified by attaching a semi-cylindrical reflector to its exposed base to obtain the Reverse-side Absorberplate solar still (RASS). Solar radiation thus impinges on the absorber plate from both the top-side and below. Outdoor tests were conducted on experimental models of both the RASS and the SSBSS of similar dimensions to obtain diurnal variations in absorber-plate temperatures, Tp, glass cover temperatures, Tgc, instantaneous distillate outputs, mw,inst, cumulative distillate distillate yields, Mw,cum, and cumulative still efficiencies, Șcum. Compared to the SSBSS, significantly higher absorber-plate temperatures were recorded by the RASS, and overall daily distillate yields from the RASS were up to 46% above those obtained from the SSBSS. However, the cumulative efficiencies of the RASS (26-29%) were lower than those of the SSBSS (3540%). The tests also showed that distillate yields from both stills were improved by increasing the initial masses of water contained in the stills.