Experimental Investigation of Heat Transfer Enhancement and Flow of Spiral Coil Heat Exchanger for Ag, Cu and ZrO2 Nanofluids

Abstract

This investigation was carried out to study the effect of silver, copper, oxide zirconium – distilled water nanofluids on enhancement heat transfer in a shell and helically coiled tube heat exchanger by changing flow. This study was done by changing the parallel flow configuration into counter flow configuration under turbulent flow regime. The nanofluids (Ag, Cu and ZrO2 – distilled water) at0.5%,1%,2%,3% and 5% particle volume concentration were prepared by two step method. The nanofluid can be applied in helical coiled tube heat exchanger to enhancement heat transfer. The use of nanofluid (Ag, Cu and ZrO2 – DW) significant gives higher Nusselt number than distilled water base fluid. The presence of Ag, Cu and ZrO2 nanoparticles attributes to the generation of strong nanoconvection current and better mixing. Nanofluids that contain metal nanoparticles Ag, Cu show more enhancements compared to oxide nanofluids ZrO2 – DW The shear stress of nanofluids increases with an increase in concentration of nanoparticles for both parallel flow and counter flow. No much impact of changing flow direction on overall heat transfer coefficient and the nanofluids (Ag, Cu and ZrO2– DW) behaves as the Newtonian fluid for 0.5%, 1%, 2%, 3% and 5%. The pressure drop and friction factor of the nanofluid are approximately the same as those of water. This implies that the nanofluid incurs no penalty of pump power and may be suitable for practical application. This study indicated that the thermal performance from nanofluid (Ag – DW) is higher than (Cu – DW) and (ZrO2 – DW) due to higher thermal conductivity for the silver