Two-phase pressure drop during upward cross flow in triangular tube bundle

Escola de Engenharia de São Carlos, University of São Paulo, Av. Trabalhador Sao Carlense, 400, CEP 13566-590, São Carlos, São Paulo, Brazil – Mechanical Engineering Department. Phone number: +55 16 3373-9415

^a Corresponding author: fabio.kanizawa@usp.br

Abstract

This paper presents experimental results for pressure drop during air-water upward two-phase flow across horizontal triangular tube bundle. It is estimated that more than half of shell-and-tube heat exchangers in industry operate under two-phase flow conditions in the shell side. However the number of research and publications focused on external flow is considerably reduced when compared to intube flow. This study addresses experimental results for pressure drop during external flow of air and water mixtures across a triangular tube bundle counting with 19 mm OD tubes and 24 mm transverse pitch, for superficial velocities up to 0.553 and 10 m/s for water and air, respectively. For reduced mass velocities, the gravitational pressure drop parcel is dominant, consequently the adoption of an appropriate methodology for void fraction estimative is essential for accurate estimative of the gravitational pressure drop parcel. The experimental results are compared with predictive methods available in the open literature, and an analysis of this comparison is presented.