CFD modeling analysis of a vertical gas liquid separator

Two-phase vertical separators are conventionally used in the oil and gas industry for primary gas-liquid separation. An efficient gas-liquid separation is important to avert downstream process equipment problems and also to meet required export quality. This paper presents a compact vertical gas-liquid separator design with an inlet cyclone and a perforated baffle plate internal configuration. The effects of inlet volume fraction variation at 0.75 m/s inlet velocity on the separation performance were investigated. The evaluation was carried out for four different inlet liquid volume fractions (0.1, 0.15, 0.2, and 0.3) by means of Computational Fluid Dynamics (CFD) modeling. ANSYS Fluent 2019 R3 was used to simulate the turbulent two-phase flow, with the Eulerian mixture and Re-Normalization Group k-epsilon models used to evaluate the complex multi-flow separation process. The simulation results then revealed the effects of inlet stream fluid volume fraction variations on separation efficiency. The separation efficiency decreased with increasing inlet Liquid Volume Fraction (LVF). The highest separation efficiency is obtained as 99.9% when the inlet LVF is between 0.1 and 0.2, and 11.63% at LVF of 0.3. Hence, the optimum inlet fluid volume fraction for this study compact geometry separator was identified at the studied inlet conditions and recommendations for future work based on the result of this study computational analysis was presented.