Abstract :

The heat exchanger performance of a system can be enhancedemploying a combination of passive strategies, particularly nanofluids and varied structures of fins geometries. These methods can enhance the heat transfer coefficient and consequently reduce the weight of the system. In this paper, the effect of fin geometry and nanofluids in Plate Fin Heat Exchangers (PFHE) are studied by numerical analysis. The forced convective heat transfer performance is evaluated in terms of Nanofluid Thermal Performance Number ( NTPN), Nusselt number and Colburn j factor.Pressure drop characteristics is estimated in terms of Fanning friction factor ‘f’ of the CNT-H2O nanofluid in the turbulent zone of Reynolds number in the range 3000 to 7500. Thermo-hydraulic performance variations with rectangular fin geometry and volume fraction 3% to 5% of the nanoparticles in nanofluid is analyzed.Performance of the nanofluids are also compared with the performance of pure water. It has been observed that heat transfer enhancement using nanofluid is more than 20%. A correlation of Fanning friction factor ‘f’ and Colburn j factor with geometry of fin, Reynolds number and volume fraction of nanofluid is developed. This correlation is the heart of the rating and design of PFHEs.