CFD investigation of fouling mechanisms in the crude oil preheat network

Abstract

Fouling phenomena, generally related to heavy crude oils and bituminous petroleum fractions, nevertheless affects significantly the preheat train (PHT) of the light Algerian crude oil. In this study, a two dimensional model was developed using the computational fluid dynamic (CFD) method in order to investigate fouling behavior in the PHT of Algiers refinery. A fouling model was proposed specifically for the studied crude oil. The model includes a pseudo detailed chemical kinetic mechanism and it considers the deposition of inorganic matters. The proposed model was validated using the experimental results from literature. The simulation results show good agreements with the experimental data. The deposition mechanism of the two fouling routes was studied by analyzing the effect of flow velocity on the thermo-hydraulic conditions of near wall regions. The results indicate that the chemical reaction fouling is controlled by kinetic reaction process and the deposition of inorganic species is dominated by mass diffusion. The distribution of the initial fouling rate was evaluated along the entire heat exchangers network. The simulation results show that the inorganic process was predominant at the first heat exchanger and the chemical reaction fouling reaches its maximum at the PHT outlet.