Productivity enhancement of solar still by using porous absorber with bubble-wrap insulation

The present work involves a solar water de-salting system with carbon impregnated foam (CIF) with bubble-wrap (BW) insulation for fresh water productivity enhancement. The said solar water de-salting system is single slope solar still (SSSS) of area 0.50 m². Four identical SSSSs were constructed and the performance was evaluated in the same climatic conditions of Chennai (13.08°N latitude, 80.27°E longitude). The CIF of diameter 0.17 m and thickness of 0.015 m was allowed to float on the water surface. Since the CIF was open pore and hydrophilic, the floating absorbers acted as thermal storage and increased the evaporative surface area of the basin. The temperature distributions on the floating absorbers are investigated with computational fluid dynamics (CFD) analysis. The result shows that the simulation of temperature distribution has good agreement with experimentally recorded data. Three modes of operation were tested: (i) SSSS without insulation, (ii) SSSS with BW insulation and (iii) SSSS-CIF with BW insulation. The results were compared with a conventional solar still (CSS) with sawdust insulation. The climatic parameters like wind, ambient temperature, solar radiation and internal temperatures of the SSSS were measured at frequent intervals of time. The water quality tests were carried out and their results were compared with rain water samples. The results showed that the productivity of the SSSS without insulation, SSSS with BW insulation, SSSS-CIF with BW insulation and CSS with sawdust insulation are 1.9 l/m²/day, 2.3 l/m²/day, 3.1 l/m²/day and 2.2 l/m²/day, respectively.