Study on concentric tube heat exchanger heat transfer performance using Al2O3 – water based nanofluids

In the present study, the heat transfer characteristics of Al2O3 – water nanofluids as a coolant used in concentric tube heat exchanger are presented. The heat exchanger is fabricated from copper concentric inner tube with a length of 1000 mm. The nanofluids are the mixture of water as base fluid and Al2O3 particles in nanorange. The results obtained from the nanofluids cooling in concentric tube heat exchanger are compared with those from base fluids. The effects of inlet flow rate of hot fluids, Reynoldʹs number and composition of nanofluids on concentric tube heat exchanger are considered. It is observed that average heat transfer rates for nanofluids as cooling media are higher than those for the water as cooling media, and this increases with concentration of nanofluidsʹ composition. The results of this study have technological importance for the efficient design of concentric tube heat exchanger to enhance cooling performance at low heat flux cooling systems.