Simulating Bubbling Bed Combustors Using Two-Fluid Models

4 Simulating Bubbling Bed Combustors Using Two-Fluid Models 

In this section the application of multiphase flow theory to model the performance of fluidized bed reactors is outlined. A number of models for fluidized bed reactor flows have been established based on solving the average fundamental continuity, momentum and turbulent kinetic energy equations. The conventional granular flow theory for dense beds has been reviewed in chap 4. However, the majority of the papers published on this topic still focus on pure gas-particle flows, intending to develop closures that are able to predict the important flow phenomena observed analyzing experimental data. Very few attempts have been made to predict the performance of chemical reactive processes using this type of model. 

According to Enwald Almstedt [40], the existing ensemble averaged two-fluid model closures for bubbling beds, developed by Simonin and co-workers (e.g., [123, 122, 33, 11, 64, 65, 7, 8, 126, 9, 100]), Drew [35], Drew and Lahey [36], and the group at Chalmers University of Technology (e.g., [39, 108, 109, 110, 40, 41]), are frequently divided into four different model classes. 

With increasing model complexity, these model versions are  

The continuity and momentum equations that are common for these model versions are listed below. The model equations adopted for non-reactive mixtures can be deduced from the more general formulations (3.293) and (3.296), respectively. 

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