Abstract
This paper presents a literature based comparative analysis of the heat transfer performance of heat exchanger systems operating with nanofluids. The study synthesizes and compares the results reported in published experimental and numerical works for different types of heat exchangers: shell and tube and plate heat exchangers. The comparison is based on key parameters including exergy efficiency ηex, overall heat transfer coefficient U, and effectiveness ε. The results are presented as functions of the Reynolds number for laminar, transitional, and turbulent flow regimes, and for different types of nanofluids, including both mono and hybrid suspensions. The analysis shows that WC/DI nanofluids provide the highest overall heat transfer coefficient in plate heat exchangers with U = 1110 W/(m2K) at Re = 525, while 0.1 % Graphene/DI nanofluids achieve the best thermal performance in shell and tube heat exchangers exceeding U values of 0.4 % Fe3O4/DI:EG and 0.4 % ND/DI:EG by 85 W/(m2K) at Re = 3000. For plate heat exchangers 0.4 % ND/DI nanofluid demonstrate the highest effectiveness with ε equals to 62 % at Re = 570, whereas in shell and tube designs the best performance is obtained for 0.1 % GNP nanofluid with effectiveness reaching approximately 97.5 % at Re = 500. Furthermore, the Cu:ZnO/DI hybrid nanofluid achieved the highest exergy efficiency 66 % while other hybrid nanofluids exhibits exergy efficiencies lower by 31–34 % at a comparable Reynolds number. The results confirm the significant influence of nanofluid composition and Reynolds number in optimizing heat transfer efficiency.