Session: 01-01-01 Automotive Flows

Paper Number: 89309

89309 - System Dynamics and Tomography-Based Control of a Gas-Liquid Inline Swirl Separator 

Swirl-based separators are widely used in the separation of two-phase flows with phases of different densities, e.g. in the oil and gas industry. The separation is based on the centrifugal forces associated with the swirl motion, pushing the light phase to the center and  dividing the original mixture into a light-phase core and a heavy-phase annulus, which are captured at two separate outlets equipped with control valves. Due to the complex (unsteady) dynamics of the flow and fluctuations in the upcoming mixture, real-time controllers are required in order to keep an optimal separation. Traditionally, the control is based on pressure measurements at the boundaries of the separator. However, pressure is only indirectly related to the actual  separation. A more direct (and potentially more effective) control variable is given by the distribution of phases inside the separator, which can be monitored using soft-field tomography. This idea is explored in this work using an air-water inline-swirl separator facility equipped with an Electrical Resistance Tomography (ERT) sensor. The position and size of the air core is determined in real-time using a newly developed fast ERT reconstruction algorithm. The dynamics of the system was studied for a pair of gas-liquid flow rates, subjected to different disturbances in the upcoming mixture and different valve actions. This lead to the determination of the “transfer function” of the process, which was used to design a PI controller. The approach was successful and the control strategy implemented allowed to keep the air core near the set-point in the presence of disturbances in the air flowrate reaching the separator.

Presenting Author: Matheus Garcia TU Delft