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Performance enhancement studies in a thermosyphon flat plate solar water heater with copper oxide nanofluid

Experiments were conducted on a thermosyphon type flat plate collector (FPC), inclined at 45o, for water heating application. Water and water based nanofluids were used as absorber fluid to gain heat from solar ray’s incident on the FPC. Nanofluids were prepared by adding Copper Oxide nanoparticles of 40-50nm size to the base fluid at 0.1, 0.2, 0.3 and 0.5 percentage by weight (z). The hot absorber fluid was made to circulate in the shell side of a heat exchanger, placed at the top of the FPC, where utility water was circulated inside a helically coiled copper tube. Temperatures at strategic locations in the FPC, working fluid, utility water inlet and outlet were measured. The nanofluid increases the collector efficiency with increasingz. A highest efficiency enhancement of 5.7% was observed for the nanofluid with z = 0.2 having a mass flow rate of 0.0033 kg/s. Three dimensional, steady state, conjugate heat transfer CFD analyses were carried out using the Ansys Fluent 15.0 software. Theoretically estimated buoyancy induced fluid flow rates were close with the CFD predictions and thus validates the computational methodology.
PAPER REVISED: 2015-12-28
PAPER ACCEPTED: 2016-01-11
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