Efficiency of a Flat-plate Solar Collector with Water-based MWCNT Nanofluids

摘要

In this paper, the efficiency of a flat-plate solar collector with water-based multi walled carbon nanotube (MWCNT) nanofluids is analytically evaluated by using simplified analytical solution of a nondimensionalized 2-D heat equation incluiding the measured exticition coefficient of the nanofluids. The water-based MWCNT nanofluids are prepared as a solar thermal energy absorbing medium and their extinction coefficients are experimentally measured by means of the Lambert-Beer law. To clearly identify the key parameters and also to assess the efficiency of the solar collector, nondimensionalized 2-D heat equation is solved and the simplified solution of dimensionless temperature is presented at a fixed wavelength. Based on the results, the efficiencies of nanofluid solar collector are estimated. We report that the efficiency of nanofluid-based solar colletor increases with particle loadings and exceeds traditional collector's efficiency after 0.012 vol.%.