Eventos Anais de eventos
CONEM 2022
XI Congresso Nacional de Engenharia Mecânica - CONEM 2022
Experimental and numerical study of two-phase slug flow in a long vertical pipe
Submission Author:
Gabriela Pereira Toledo , SP
Co-Authors:
Gabriela Pereira Toledo, Ricardo Augusto Mazza
Presenter: Gabriela Pereira Toledo
doi://10.26678/ABCM.CONEM2022.CON22-0498
Abstract
In a two-phase flow, the phases can be arranged in different flow patterns depending on pipeline geometry and each phase’s superficial velocities (JG and JL). The slug flow occurs in many industrial situations, such as nuclear reactors, oil extraction from wells, and power plants, among other applications. The upward vertical slug pattern is characterized by concentric elongated bubbles followed by an aerated liquid slug, creating a quasi-periodic flow. The bubble and tube have almost the same diameter. Due to the wide practical use, it is clear the importance of developing studies to better understand the slug flow characteristics along the pipe. Different from horizontal flows, vertical flows need a longer length to reach a fully developed flow. There are few experimental data involving air-water flow in vertical pipes with more than one measurement point along the line in the literature. Even in these studies, the test section is short. This paper aims to study the progression of the slug flow of air-water in a long vertical test section. The experiment was carried out on a line of ID 23.4 mm and a dimensionless length of 1,434D. The experimental setup has three stations equipped with pressure sensors. The pressure sensor measures the pressure gradient, and the void fraction is determined using the quick close valves technique. The experimental results are compared with a semi-analytical model to assess the model’s prevision capabilities. The drift relation for the data is analyzed. The numerical model agreed with the experimental data from a long vertical test section, showing less than a 5% deviation for the pressure gradient.
Keywords
Slug Flow, air-water flow, pressure gradient, void fraction
