CFD analysis of helically coiled tube for compact heat exchangers

Abstract

A helically coil-tube heat exchanger is generally applied in industrial applications due to its compact structure, larger heat transfer area and higher heat transfer capability, etc. The importance of compact heat exchangers (CHEs) has been recognized in aerospace, automobile, gas turbine power plants, and other industries for the last 60 years or more due to several factors as mentioned above. However flow and heat transfer phenomena related to helically coil-tube heat exchanger are very sophisticated. A computational fluid dynamics (CFD) methodology using ANSYS FLUENT 13.0 is used here to investigate effects of different curvature ratio on the heat transfer characteristics in a helically coil-tube. Simulation has been done for different curvature ratios of a helical coil tube by varying different inlet conditions like velocity-inlet and pressure-inlet for different flow and heat transfer conditions.‬ ‬Based on the simulation results, the complicated phenomena occurred within a helical coil-tube can be reasonably captured, including heat transfer behaviors from the entrance region, etc. For all the cases considered in this work, heat transfer coefficient, Nusselt number, pressure drop, Colburn factor and fRe are being computed and studied to analyze the heat transfer characteristics of a helical coil tube.