Comparison of experimental and computational study of the fluid dynamics in fluidized beds with agglomerates

Abstract

Particle agglomeration is one of the obstacles for successful application and commercial breakthrough of fluidized bed biomass gasification. The problem is generally associated with molten ash components that interact with the bed particles, forming agglomerates that interfere with the flow behavior. In this work experimental and computational study are combined in order to gain more insight into the fluid dynamics in a bubbling fluidized bed gasifier. The goal is to develop a Computational Particle Fluid Dynamic (CPFD) model that can be used in further investigations of the correlation between flow behavior and bed agglomeration during biomass gasification in fluidized beds. The experimental part was performed in a 20 kW laboratory scale bubbling fluidized bed system. The commercial CPFD software Barracuda Virtual Reactor (VR) version 17.4.1 was used for the computational study. Simulation results were compared to the experimental data in order to validate the CPFD model. Pressure drops predicted by the simulations were in good agreement with the experimental measurements, which indicate that the model is well capable of studying the fluid dynamics in a fluidized bed system.