Comprehensive numerical and experimental analysis of dynamic gas-liquid separator with various oil-gas ratios

Abstract

Dynamic gas-liquid separator is a critical equipment extensively utilized in oil extraction, the nuclear industry, and chemical engineering. The operating parameters, such as flow rate and oil-gas ratio, can vary significantly in real-world applications. To enhance the separator’s performance, this study employs the computational fluid dynamics (CFD)–population balance model (PBM) method to investigate how different oil-gas ratios affect the internal flow field and the overall performance of the dynamic gas-liquid separator. An experimental platform was constructed to test various oil-gas ratios, and the numerical results were compared with experimental data to validate the numerical model's accuracy and reliability. The findings indicate a positive correlation between the oil-gas ratio and both separation performance and energy consumption. As the oil-gas ratio increases, the internal flow field becomes more stable, which is conducive to gas-liquid separation, thereby enhancing the separator's efficiency. However, this also leads to increased energy consumption due to the higher liquid phase volume fraction, necessitating greater power to maintain stable operation. For instance, when the Q_o=60 m³‧d^-1 and ε increases from 0.5 to 2.5, the degassing rate, power and pressure difference of the separator increase by 20.24 %, 210.03 % and 176.67 %, respectively. Interestingly, while the separator’s degassing rate decreases with a higher flow rate, the deoiling rate improves. The optimal separation efficiency was achieved at a flow rate of 140 m³·d⁻¹, where the degassing and deoiling rates reached 95.21 % and 93.97 %, respectively. As the flow rate continues to rise, the fluid volume per unit time, energy consumption, power requirements, and differential pressure also increase. Based on these findings, prediction equations for separator performance across various oil-gas ratios were developed. These equations offer a valuable theoretical foundation for designing, operating, and optimizing high-performance dynamic separators, contributing to the efficiency and sustainability of industrial applications.