Thermal Performance of Low Flux Solar Collectors Using Al2O3– H2O Based Nanofluids

Abstract

Due to the growing demand of energy and lesser availability of fossil fuels, it shifts our concern towards Renewable energy sources. From all of the sources available to us solar energy is the best option with minimum environmental impact. But the problem lies in efficiently collecting and converting this energy into something useful form. The present study has been carried out to increase the efficiency of the solar collector by using new type of solar collector(DASC-Direct absorption Solar collector) and different class of fluids called(Nanofluids). In conventional type of flat plate solar collectors we get three resistances whereas in DASC these three resistances are reduced to one. In the present work we have evaluated the collector efficiency using water and Al2O3 nanofluid with volume concentration .005% and .05% at different mass flow rates 60,80 and 100ml/hr. Also the variation of temperature difference with time is also plotted. By performing the experiment it has been found that the efficiency of the flat plate DASC using Al2O3 nanofluid is 3-4% more than using the water. Whereas if we compare two concentrations of Nanofluids, at higher concentrations the tendency of the nanoparticles to settle down is higher. By varying the mass flow rate and varying the volume concentration of nanoparticles in nanofluids the variation in collector efficiency and temperature difference are studied. At last the comparison of efficiency graphs of Al2O3 and Cuo Nanofluids at same concentration are done.