Numerical Investigation on Heat Transfer Performance Using Therminol-55 Fluid in an Internally Six Head Ribbed Tube

Abstract

For the last several decades, rising energy value and higher material cost coerced researchers all around the world to discover innovative ways of increasing heat transfer performance in all kinds of heat exchangers (HXs). Thermal and hydraulic performance of heat exchanger can be improved in various ways such as change of geometry of the tubes, change of heat transfer fluid etc. In this paper the thermo-hydraulic performance of smooth tube, internally four head ribbed tube has been described and from the analysis of the simulation results a new design of the model has been developed that is internally six head ribbed tube. Through simulation and calculation, the convective heat transfer coefficient and Nusselt number of Therminol 55 in a smooth tube, four head and six head ribbed tube has been determined. Comparison between smooth tube and internally four head and six head ribbed tube has been done which shows that the hast transfer rate of internally four head ribbed tube is increased by 8.2-13.2 percent as compared to the smooth one and heat transfer rate of internally six head ribbed tube is increased by 1.85-2.88 percent as compared to four head ribbed tube. Numerical simulation of three dimensional flow of Therminol 55 heat transfer fluid validates that the heat transfer is improved as the rib valley gives a high heat transfer rate by ribs based on Renormalization group (RNG) k-ε turbulent model in the internally four head ribbed tube.