Experimental Investigation of Double Pipe Heat Exchanger Performance based on Alumina and Copper Oxide Working Nanofluids

Abstract

The heat transfer performance of heat exchanger is greatly depending on the thermal conductivity and heat transfer capacity of the working fluid. One of the important methods to improve the thermal conductivity of the heat transfer fluid is by adding nano particles of materials with high thermal conductivity. In the present study, an experimental work was conducted to investigate the performance enhancement of double pipe heat exchanger using Alumina (Al2O3) and Copper oxide (CuO) nano particles mixed with engine oil as a working fluid. The thermal performance of heat exchanger was investigated at particles concentrations 0.05% and 0.1% of Al2O3 and CuO nano particles to determine the most effective factors on heat transfer enhancement. The results revealed that, the enhancement percentage in Nusselt number (Nu) for nanofluid at 0.05% particles concentration compared to pure oil was 9% and 6% for CuO and Al2O3 nanofluids respectively. While at 0.1% concentration, the enhancement percentage in Nu was about 17% and 15% for CuO and Al2O3 nanofluids respectively. The enhancement percentage in value of overall heat transfer coefficient for CuO nanofluid was 6.5% compared to Al2O3 nanofluid at 0.1% concentration. The enhancement percentage in the heat exchanger effectiveness was about 12% for CuO nanofluid compared with that for Al2O3 at 0.1% concentration. Adding the CuO and Al2O3 nano particles has improved the thermal conductivity of base fluid (oil) and led to a significant enhancement in heat transfer rate and thermal performance of the heat exchanger.