ENHANCEMENT OF PERFORMANCE OF SOLAR FLAT PLATE COLLECTOR USING NANOFLUIDS

Abstract

With increasing pace of development burden on convectional sources such as coal, oil and natural gas is increasing day by day. One of the most serious problems confronting the future use of coal is the Kyoto Protocol greenhouse gas reduction targets. The increase in the value of fossil fuels and speedy depletion of standard energy sources are major reasons among the key energy issues. Solar collector, as a sort of green and renewable energy device, will sort out the problem of these energy issues. Low efficiency and high price of solar collectors when compared to traditional devices persuade scientists and engineers to make effort to enhance performance of solar collectors. The performance of a solar collector depends on absorber plate design, insolation, insulation and losses, type of glass, base fluid etc. Nanofluid, the suspension of nanoparticles into a basefluid, has predominant characteristics as a result of nanoparticles tiny size and high extent. Using Nanofluid instead of conventional fluid improves heat transfer as well as optical and thermal properties, efficiency, transmission and extinction coefficient of solar collector. The enhancement in performance of solar collector using Al2O3 (20nm) nanofluid in comparison to conventional fluid has been studied here. For the testing purpose a flat plate solar collector was fabricated. The mass flow rate was varied from 0.5 l.p.m to 2.5 l.p.m (0.5, 1.0, 1.5, 2.0 & 2.5) and volume fraction of nanofluid was varied from 0.01 vol.% to 0.15 vol.% (0.01, 0.02, 0.04, 0.075 & 0.15). Experiments were carried out with stable nanofluid. The optimum condition for maximum efficiency was found to be 2.0 l.p.m and 0.15 vol.%. The efficiency was found to increase from 46.3 % to 73.1 %. A maximum rise in temperature of 22 0C was obtained for 0.5 l.p.m and 0.15 vol.% nanofluid and 14 0C in case of water.