MODELING CAVITATION OF OIL-CONTAINING MEDIA IN VARIOUS HYDRODYNAMIC CONFIGURATIONS

Abstract

Increasing the depth of crude oil refining at domestic and foreign refineries is an important technological challenge under conditions of a growing share of heavy crude feedstock. This study presents the results of numerical modeling of hydrodynamic cavitation in various cavitation device configurations intended for the treatment of crude oil and oil-containing media. Four hydrodynamic cavitator designs were considered: a conventional Venturi nozzle, a modified Venturi nozzle with a conical flow body, a cavitator with cylindrical flow bodies, and a multichamber cavitator with sequentially arranged expansion chambers. The calculations were performed using ANSYS CFX with a two-phase “liquid oil–oil vapor” mixture model, a cavitation model based on the Rayleigh–Plesset equation, and the standard k–ε turbulence model. Pressure, velocity, and vapor-phase volume fraction distributions, as well as the spatial localization of the cavitation zone, were analyzed as comparative criteria. The results demonstrated that the geometry of the flow section significantly affects the intensity, extent, and location of the cavitation region. The most favorable results were obtained for the cavitator with cylindrical flow bodies. At flow velocities of 0.7–0.9 m/s, a developed cavitation cloud was formed predominantly in the central part of the channel and remained separated from the walls by a liquid-phase layer. This configuration provides high cavitation activity while reducing the potential risk of cavitation erosion. Particular attention was paid to comparing cavitation intensity with the extent of cavitation contact with the device surfaces. Options for integrating cavitation devices into the process flow scheme of crude oil preparation and primary refining were proposed. Potential effects of cavitation treatment, including intensified degassing and a possible increase in the yield of light fractions, were discussed. The obtained results provide a basis for further experimental validation, optimization of cavitator geometry, and evaluation of its performance under actual process conditions.