Wall Heat Transfer of a Small Blunt Body Immersed in a Fluidized Bed

Abstract

In the present study, heat transfer through the wall of a blunt body immersed in a fluidized bed was investigated. A Eulerian approach based on the kinetic theory was used to simulate the multiphase thermal flow, and the determined heat transfer coefficients indicated the existence of different heat transfer patterns in the different walls of the blunt body. It was observed that, with increasing inlet gas velocity, the time-area-averaged heat transfer coefficients of the walls of the bodies HC1-HC3 rapidly increased and then gradually decreased. However, the heat transfer patterns in the walls of the bodies HC4 and HC5, which were initially located outside the bed, were different. The peculiar heat transport phenomena were further investigated by statistical methods.

A numerical study on biomass fast pyrolysis process: A comparison between full lumped modeling and hybrid modeling combined with CFD

“…Accordingly, the reaction rate of the tar shows a higher magnitude near the wall as the tar is generated from biomass feedstock. The heat transfer rate is more increased between solid-solid interfaces than that of solid-gas interface (Choi, 2011(Choi, , 2012(Choi, , 2015. Hence, the higher heat transfer rate between solid-solid interfaces increases the emulsion temperature and finally enhances the primary degradation rate of the biomass.…”

“…5 and Table 3, respectively. To validate the present CFD method, a bubbling fluidized bed was calculated, and the results were compared with the experimental results (Hulme et al, 2005) as like earlier studies (Choi, 2011(Choi, , 2012(Choi, , 2015. The hydrodynamics and heat transfer behavior which are very important for the simulation of mixing and chemical reaction of gas-solid multiphase reacting flow are analyzed in the bubbling fluidized bed.…”