Modified active solar distillation system employing directly absorbing Therminol 55–Al2O3 nano heat transfer fluid and Fresnel lens concentrator.

Abstract This paper reports the design and construction of a modified active solar distillation system (MSDS) and comparison of its performance parameters with that of a conventional solar still (CSS). MSDS consists of a solar still, a Fresnel lens concentrator with an evacuated receiver tube and a serpentine loop type heat exchanger. Al 2 O 3 –Therminol-55 nanofluid (nHTF) is used as the heat transfer fluid in the solar collector loop. Various performance parameters of MSDS and CSS such as saline water temperature, hourly yield and total yield have been compared under the ambient and solar conditions prevailing at Trichy. The experimental results indicate the hourly yield of MSDS with 0.1% nHTF is 45–250.27% more than CSS, and the total yield of MSDS with 0.1% nHTF is 12.190 L/m2 day compared to 3.48 L/m2 day for CSS. The daily efficiency of MSDS is found to vary with volumetric concentration of nanofluid, and maximum efficiency of 53.55% is obtained for 0.1% nHTF. Estimated cost for production of one litre-distilled water is approximately 1.54 INR for CSS and 1.41 INR for MSDS. MSDS developed in this study is found to be a better alternative to the CSS still due to its high productivity and cost-effectiveness. Highlights • Performance of the modified solar distillation system (MSDS) is evaluated experimentally. • Total freshwater yield enhanced by 250.27% for MSDS compared to conventional solar still. • The daily average efficiency of MSDS is found varying with the concentration of nano fluid. • MSDS can lead to better alternatives to replace the conventional solar still. [ABSTRACT FROM AUTHOR]