Hydrocyclone Separation Efficiency Modeled by Flow Resistances and Droplet Trajectories

The growing demand to optimize the deoiling performance for offshore oil & gas gives the incentive to improve existing control solutions by means of model-based control solutions. This paper proposes a separation efficiency grey-box model of a deoiling hydrocyclone. Grey box modeling of deoiling hydrocyclones aims to combine knowledge from fluid dynamics with the data-driven parameter estimation to yield better accuracy than black-box derived models while keeping the computational load much lower than CFD-simulations. The model has to be reasonably accurate in all likely operating conditions and be computed in real-time, in order to be beneficial for advanced model-based control. The developed grey-box model is based on flow resistance and oil droplet trajectory analysis. The model functionally describes how the valve openings, inflow rates, and PDR set-points affect separation efficiency of the considered generic deoiling hydrocyclone. The results are reasonable and provide a fundamental overview of how the operational conditions affect separation efficiency. The model can be extended to account for changes in the axial velocity distribution, coalescence and breakup of droplets. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.