Performance evaluation of an air-cooled heat exchange system for hybrid nanofluids

This study used an acetylene flame synthesis system to prepare hybrid carbon nanofluids (HCNFs) containing amorphous carbon, graphene oxide, and graphite-2H as a working fluid for heat exchange applications. In addition, sodium dodecyl sulfate was added to the prepared HCNFs as a dispersant to reinforce their dispersion and suspension performance. The basic characteristics of the HCNFs were measured and analyzed. Finally, the HCNFs were applied in a cooling system with an air-cooled heat exchanger (ACHE) to evaluate the pumping power consumption, heat exchange capacity (Q̇_ex), and system efficiency factor (SEF) of the ACHE under turbulent flow. The results show that the pumping power and ̇_ex of the ACHE cooling system increased with the HCNF concentration under all experimental conditions. The maximum enhancements in Q̇_ex and SEF for the HCNFs at 0.02 wt.% were respectively approximately 13.0% and 11.7% at a flow rate of 2.0 L/min (compared with those of water).