Detailed analysis of fin-and-tube evaporators

Abstract

This paper is devoted to the presentation of a new model for fin-and-tube evaporators, focusing on the solid core simulation and its integration with a quasi-homogeneous two-phase flow model for the in-tube refrigerant flow. Special attention is dedicated to separated in-tube flow patterns (stratified, stratified-wavy), because of their importance in liquid overfeed evaporators and the impact on the solid core temperature distribution. The paper presents the solid core formulation and numerical method, the intube two-phase flow model, and describes the proposed integration algorithm between them. A selected single-tube case is analysed in full detail, showing the impact of stratified flow on the fin and tube temperature distributions. Additional studies are finally presented on fin-tube contact aspects as thermal contact resistance and partial contact.