Heat transfer performance of nanofluids in facility heating applications

Abstract

"Nanofluids are a class of fluids comprised of a base fluid with nanoparticles in a colloidal suspension. These fluids have been shown to exhibit substantially higher thermal conductivity than their corresponding base fluids. Investigation is required to determine if this property may be exploited for the purpose of improving the performance of systems employing liquid heat transfer. Detailed analyses of CuO/60% ethylene glycol and Al₂O₃/60% ethylene glycol nanofluids' heat transfer properties were conducted to determine if they provide a net benefit in commercial facility heating systems. The analyses employed previously developed correlations for nanofluid thermophysical, fluid dynamic and heat transfer properties. Computational models were also developed to characterize the performance of hydronic finned tube heaters and air heating coils with nanofluids, and to compare the nanofluids' performance with that of their base fluids. Several aspects of heat transfer performance were analyzed including heating output, frictional pressure loss, and associated pumping power. These data are analyzed to determine if the selected nanofluids can improve heating output, reduce required liquid pumping power or reduce the size of heating equipment. The analyses predict that the nanofluids examined exhibit superior heat transfer performance to that of the base fluids under certain conditions"--Leaf iii