application of pilot-scale prepared fe2o3 water-based nanofluid in a direct tube solar collector

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#