March 6 - 8, 2017 | Berlin
LEADING ENGINEERING SIMULATION CONFERENCE
The Gas-Liquid Cylindrical Cyclone (GLCC) is one of the main alternative of conventional vessel-type separators of a two-phase gas-liquid mixture, since it is more compact, simple and has a lower footprint. The main objective of this study is to use CFD modelling, in STAR-CCM+® software using VOF model, in order to evaluate the effect of geometrical modifications in the reduction of LCO and GCU.
CFD simulations for single-phase flow are carried out in order to validate the swirling flow from experimental data acquired by Erdal (2001). Axial and tangential velocities profiles are compared, obtaining fair agreement. CFD simulations for two-phase flow were done under zero net liquid flow. The average liquid holdup is compared with Kanshio (2015) experimental data. A good agreement is obtained between experimental data and CFD simulations, with RMS errors around 13%.
An experimental setup is built in order to validate a CFD model. LCO data is acquired and pressure transmitters are used at each outlet. An error below 6% is obtained comparing CFD simulations with experimental data. Once the model is validated, five geometrical variables are tested with CFD. Those variables are the inclination angle of inlet, the height of inlet, the effect of a dual inlet, the influence of a nozzle at the inlet and the effect of a volute inlet with rectangular slot. The best options of the evaluated levels are an angle of 27°, the inlet located 10 cm above the center, a dual inlet with 20 cm of spacing between both inlets, a nozzle of 3.5 cm of diameter and a volute inlet of 15% of pipe area. The combination of these options in the same geometry reduced LCO in 98%. Finally, the swirling decaying is studied with vector velocities profiles and is found that liquid has a greater impact than gas.