A novel one-dimensional model to predict fin efficiency of continuous fin-tube heat exchangers

Abstract

The objective of this contribution is to present a novel one-dimensional (1D) model to predict the heat transfer rate from (or to) continuous fin-and-tube heat exchangers. In this model, called two equivalent radial fins (1D-TERF), it is proposed to represent the thermal behavior of the continuous two dimensional (2D) fin by employing two thermally independent sections of radial fins, while keeping the total surface area of the actual fin and the outer perimeter of the tube. The two geometrical free parameters of the model are obtained by matching the two first terms of the series describing the actual fin efficiency at low values of the modulus, Φ=ℓh/(kδ). It is demonstrated that the 1D-TERF model with this criterion allows estimating the fin efficiency with a higher level of precision than any other literature alternative (as the radial equivalent fin model and the sector method) over a wide range of conditions (i.e., values of Φ between 0 and infinity) for circular tubes with in-line and staggered layouts in an extensive range of geometric ratios.