Application of pilot-scale prepared Fe2O3 water-based nanoﬂuid in a direct tube solar collector
Volume Title: 1
Department of Chemical Engineering, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
The widespread implementation of nanofluids in solar-thermal systems is currently hindered by their complex synthesis and their high capital cost. In this regard, this study focused on application of planetary ball milling as a low cost and eco-friendly procedure for the large scale preparation of Fe2O3 water-based nanofluid applicable in solar collectors. The solar thermal system included a direct tube solar collector (L: 1.8 m, ID: 0.05 m), a circulating refrigerator bath, two thermometers and a peristaltic pump, in which, the working fluid flowed through the collector in different flow rates (01., 0.2, 0.3, 0.4 and 0.5 L/min). The collector efficiency using Fe2O3/water nanofluid and pure water was obtained and compared under the same conditions, when the inlet temperature was temporally fixed for all the experiments. The collector efficiency with the nanofluid has grown significantly compared to the pure water and this growth decreased with increasing flow rate. At a flow rate of 0.1 L/min, Fe2O3 water-based nanofluid (0.025 vol.%) was able to enhance the collector efficiency 4.6 times more than that of the pure water.