Single slope solar distiller performance using metallic nanofluids

Abstract

Solar distillation is a thermal process used to produce freshwater from brackish or saline water by absorbing solar radiation. The single slope solar distiller has a design with a single slope cover to condensate the generated vapor and guide the water to the distillation vessel. On the other hand, metallic nanofluids (NF) are candidates to improve the thermo-optical performance of solar energy collectors due to the high optical absorption of sunlight and high thermal conductivity. In this work, we explore silver, gold, and copper NFs to increase the performance of a single slope solar distiller. The NFs were synthesized using chemical routes to obtain NFs containing spherical nanoparticles with size about 40 nm and volume fractions of φ=0.001%. The specific water production and the base, basin, cover and ambient temperatures were recorded along the day, and the results were in agreement with the predicted values obtained from the energy balance equations. Water production enhancements of 28.2%, 19.2%, and 22.0% were obtained using Au, Ag, and Cu nanofluids, respectively. The solar distiller using Au-NF exhibited the best performance, with a maximum instantaneous thermal energy efficiency enhancement of 28.9% without changes in the colloidal stability during the experiments.