Performance Investigation and Optimization of the Primary Separation Part of the Oil-Gas Separator

Oil-gas separators are significant in the safe and reliable operation of the natural gas storage system. The separation efficiency of the conventional primary separation part of the oil-gas separator was not high enough, causing the insufficient performance of the whole separator. Three modification schemes were proposed to optimize the primary separation part of the oil-gas separator, including adding a curved baffle at the entrance, forming a centrifugal separation through the tangential inlet, and forming a cyclone structure by adding an inner cylinder. The separation performance was obtained through the Eulerian–Lagrangian approach numerically. For each scheme, a variety of parameter combinations were designed by the orthogonal array and the structure with the highest separation efficiency was reasonably selected. The separation efficiency of the centrifugal structure was higher than that of the collision structure on the whole. To evaluate the feasibility of the practical application, the three structural schemes were compared coupled with the analytic hierarchy process (AHP) based on the separation efficiency, the pressure loss, the uniformity of filter inlet velocity, and the modification cost. The results showed that the scheme of adding a curved baffle with reasonable structural parameters at the entrance had better comprehensive performance, which could be used as the optimal scheme in improving the oil-gas separator applied in natural gas storage.