Enhancement of Heat Transfer Using Fe_3O_4/Water Nanofluid with Varying Cut-Radius Twisted Tape Inserts

摘要

An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe_3O_4 nanofluid. In this work an experimental analysis on twisted tape inserts with varying cut-radius in Hair pin heat exchanger using Fe_3O_4 water based nanofluid is presented. Experimental data is generated at the mass flow rates of ranging from 0.05Kg/s to 0.25Kg/s and the Reynolds number ranging between 3000 to 25000. where as the flow rate of the hot fluid in the annulus is maintained constant (0.1Kg/s). The Heat transfer coefficient and corresponding friction factors required for performance analysis are determined for various particle volume concentrations of 0.01% and 0.03%. The Nusselt number of entire pipe for 0.03% concentrations of nanofluid with radius of cut, r=6 insert of H/D=3 is enhanced by 32.01% as compared water. The friction factor of entire pipe for 0.03% concentration of nanofluid with radius of cut, r=6 twisted tape insert of H/D=3 is enhanced by 1.21 times as compared to water. The results of the investigation shows an enhancement in the performance parameter of the heat exchanger namely heat transfer coefficient friction factor with an increase in volume concentration of the nanofluid.