Numerical investigation of the effects of nano fluid use on flow and heat transfer in a cross flow shell and tube heat exchanger

In this study, the effects of nanofluid usage on heat transfer in a cross-flow body-and-tube type heat exchanger were numerically investigated. In the shell and tube type heat exchanger, water at 20oC and TiO2/water nanofluids at 0.3, 0.5 and 0.75 volumetric ratios were used in the pipe. Oil flow is used at 150oC and 80oC on the body side. In order to obtain the appropriate network structure in the numerical solution, the heat transfer coefficients of 5 different network structures at the selected point were compared with the heat transfer coefficients found with the help of the Sieder-Tate relation and the most suitable network structure was used. In order to check the accuracy of the numerical solution, the heat transfer coefficients at the selected 4 points along the pipe were compared with the heat transfer coefficients found with the help of the Sieder-Tate equation and it was found to be in harmony. In the numerical solution, the average heat transfer coefficient for water was 2779.19 W/m2K, 2923.25 W/m2K for 0.3 TiO2/water nanofluid, 4659.28 W/m2K for 0.5 TiO2/water nanofluid, and 12073.26 W/m2K for 0.75 TiO2/water nanofluid. In the solutions obtained in this way, it was observed that the heat transfer coefficient increased as the nanofluid ratio increased.