Estudo numérico e experimental do escoamento bifásico líquido-gás em um distribuidor

Abstract

In the oil industry, two-phase separators are used in the phase separation process, however these separators (GLCC, VASPS, Pazflor, among others) have large dimensions, making their handling, installation and maintenance difficult. The size of these separators is proportional to the flow that flows through them, só an alternative to reduce the geometry would be the implementation of a previous distributor capable of equitably distributing the flows that arrive in the separator. Thus, in this work the dynamics of vertical upward liquid-gas two-phase flow in a distribution system is studied. This distribution system is composed of a condicionator, a cyclonic camera and four outlets – with the aid of experimental tests and three-dimensional transient numerical simulations. In the experimental tests were used wire-mesh sensors and a high-speed camera for the flow characterization. Numerical simulations were performed using the commercial software ANSYS – CFX R19.1. The balance equations were discretized using the finite volume based on finite elements method. For the numerical modeling was used the inhomogeneous eulerian-eulerian two-fluid model, with the SST turbulence model and the compressive scheme for capture the liquid-gas interface. The grid test was the same for the experiments and numerical simulations with the liquid surface velocity ranging from 0.5 to 1.5 m/s and the gas surface velocity ranging from 0.07 to 0.92 m/s. For these velocity pairs, the efficiency of the distribution system in question for the dispersed bubble flow pattern and the transition between dispersed and slug flow was evaluated. From the experimental results it was concluded that the distribution system can divide the flow evenly for the bubble pattern, spherical cap and transition to slug flow, with maximum deviation of 2.3% and minimum of 0.43%. The numerical model developed satisfactorily reproduced the physics and behavioral observed experimentally.