In oil an‎d gas industry processes, the presence of multiphase flows challenges the performance of downstream equipment. These flows typically consist of a gas phase, a light liquid phase (gas condensate), an‎d a heavy liquid phase (water), whose separation is essential for the proper functioning of downstream units. Two separators operating at pressures of 44 an‎d 100 bar are used in the Parsian Gas Refinery, each experiencing operational issues. In the medium-pressure separator, some water is detected in the condensate outlet stream, leading to scale formation an‎d damage to downstream equipment. The high-pressure separator suffers from liquid carryover with the gas phase, which reduces the quality of the separated gas. To address these problems, the performance of both separators was analyzed numerically an‎d transiently using Computational Fluid Dynamics (CFD). The geometry of each separator was modeled in full scale an‎d meshed in three dimensions, an‎d the governing equations were solved in ANSYS Fluent using appropriate boundary conditions. The interface between the phases was tracked using the Volume of Fluid (VOF) model, an‎d turbulence was modeled using the RNG k–ε model. In the medium-pressure separator, the effects of adding an internal baffle an‎d changing the inlet flow rate were investigated. The results showed that the additional baffle improved flow calming, enhanced water dro‎plet settling, an‎d prevented their entrainment into the condensate outlet. Consequently, the water separation efficiency increased from 91.82% in the original configuration to 95.21% with the added baffle. Furthermore, reducing the inlet flow rate improved phase separation due to longer residence time, resulting in a separation efficiency of 99.16%. For the high-pressure separator, results indicated that the inlet geometry had a significant effect on the separation performance. Among the tested designs, the hemispherical inlet showed the best performance with a separation efficiency of about 74%, followed by the flat-plate type with about 60%. Additionally, increasing the distance between the inlet an‎d the deflector reduced the separation efficiency an‎d disrupted the optimal separation conditions, highlighting the importance of proper inlet device positioning for improved separator performance.

محسن نصراصفهاني

محسن محمدي , نسرين اعتصامي