Dynamically coupling computational fluid dynamics (CFD) and steady-state model (SSM) for simulating industrial coke drum and temperature prediction

The delayed coking process is crucial for heavy oil decarbonization and needle coke production. However, experimental measurements of the temperature, internal flow field and yields for products of the coke drum are challenging due to the extreme high operation temperature and pressure, thus the precise regulation is critically difficult. In this study, a ternary-phase computational fluid dynamics (CFD) model is proposed, which treats the gas, liquid, and solid phases (coke) as independent continuous medium and incorporates the models of fluid dynamics, heat transfer and chemical reaction. The model was used to characterize the heterogenous distribution of coke, gas velocity or temperature and analyze the influence of operating temperature, gas flow field on the product yields. However, it requires great amounts of computational time to simulate industrial delayed coking reactor for single working cycle (that is usually operated over 12 h). Therefore, a steady-state model (SSM) and CFD simulations were integrated to develop a multiscale computation strategy of CFD-SSM, where SSM can provide the initial condition of temperature and chemical component for CFD while the heterogeneous reaction rates of lumped-model was revised with CFD. A comparison between the CFD-SSM and industrial measurement of temperature profiles within 12 h operation was conducted to validate the efficiency and accuracy of the new model. The present research makes a great progress in simulating the industrial coke drum and provides key theoretical insights into the coke growth for temperature operation.