Analysis of Parallel Flow Double Pipe Heat Exchanger using GW70/Cu Nanofluids

Abstract

CFD analysis is used to calculate the Nusselt number, overall heat transfer, and convective heat transfer coefficients of glycerol-water-based Cu nanofluids running in a parallel flow double pipe heat exchanger. The analysis employs a single-phase fluid approach method. The heat exchanger model was created using the Ansys 19.0 workbench. In a laminar developing flow zone, heat transfer studies with nanofluids at three flow rates (680<Re<1900) are carried out. A 500 mm long concentric double pipe heat exchanger with ID=10.2 mm, OD= 12.7 mm tube dimensions and annulus dimensions of ID=17.0 mm, OD= 19.5 mm is used for testing. The tube and annulus materials are made of copper. The three particle volume concentrations used in this investigation were 0.2 percent, 0.6 percent, and 1.0 percent. Hot water has mass flow rates of 0.2, 0.017, and 0.0085 kg/s in the tube, whereas nanofluids have mass flow rates of 0.03, 0.0255, and 0.017 kg/s in the annulus. Nanofluids have an average temperature of 36°C, whereas hot water has an average temperature of 58°C. The overall heat transfer coefficient and convective HTC of 1.0 percent copper nanofluids at 0.03 kg/s are increased by 26.2 and 46.2 percent, respectively, as compared to base liquid. When the experimental results are compared to CFD values, they are found to be quite similar.