Analysis of heat transfer and pressure drop in helical finned tube bundles with computational fluid dynamics

In this study, numerical analysis of a helical finned tube heat exchanger was performed in the Ansys-Fluent computational fluid dynamics (CFD) package program. In the numerical analysis, a constant wall temperature was defined on the outer surface of the pipe and surrounding air was used as a fluid considering the outside of the pipe with fins. In the analysis, Nusselt number and friction factor were calculated according to the obtained outlet temperatures and pressure drop, with the inlet velocities calculated in the range of 5000-20000 Re number by changing parameters such as fin height, pipe diameter, fin thickness and blade pitch in numerical studies. In addition, numerical calculations were made for circular finned tube bundles using the same boundary conditions and variable parameters, and the results were compared with helical finned tube bundles. In the helical finned tube bundles, it has been seen that increasing the pipe diameter, fin pitch increases the heat transfer, besides increasing the fin height and fin thickness decreases the heat transfer. It has been also observed that increasing the fin thickness and fin pitch increases the friction factor, besides increasing the pipe diameter and fin height decreases friction factor. In addition, it was seen that the thermal performance of the helical finned tube bundle was better than the circular finned tube bundle, but it was determined that the pressure drop was higher. The verification of numerical results was performed by compared the experimental results in the literature and a good agreement was observed between results.