CFD Simulation of Porosity and Particle Diameter Influence on WalltoBed Heat Transfer in Trickle Bed Reactors

Walltobed (or walltofluid) heat transfer issues in trickle bed reactors (TBR) has an important impact on operation and efficiency in this category of reactors. In this study, the hydrodynamic and thermal behavior of trickle bed reactors was simulated by means of computational fluid dynamics (CFD) technique. The multiphase behavior of trickle bed reactor was studied by the implementation of the EulerianEulerian multiphase approach. Also, bed porosity effect was modeled by porosity function method. In order to study the effect of operating parameters on walltobed heat transfer, the influence of catalyst particle diameter and catalytic bed porosity was investigated on walltobed Nu number. The results showed that the enhancement of catalytic bed porosity from 0.36 to 0.5 decreases the Nu number about 15% due to a reduction of liquid velocity adjacent to the reactor wall. Also, the increase of particle diameter from 4 to 6 millimeter decreases walltobed Nu number about 15% owing to a reduction in liquid phase volume fraction.