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 (Q̇ex), and system efficiency factor (SEF) of the ACHE under turbulent flow. The results show that the pumping power and Q̇ex of the ACHE cooling system increased with the HCNF concentration under all experimental conditions. The maximum enhancements in Q̇ex 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).