- Title
- CFD-DEM simulation of particle mixing and segregation in a chemical looping combustion system under cold flow conditions
- Creator
- Alghamdi, Y. A.; Peng, Z. B.; Doroodchi, E.; Moghtaderi, B.
- Relation
- 21st International Conference on Fluidized Bed Combustion (21st FBC). Proceedings of the 21st International Conference on Fluidized Bed Combustion (Naples, Italy 03-06 June, 2012) p. 1058-1065
- Publisher
- MCM Congressi
- Resource Type
- conference paper
- Date
- 2012
- Description
- This work is concerned with the development of a two dimensional Eulerian-Lagrangian based model to investigate mixing and segregation of binary mixtures of particles with different sizes and densities in a gas-solid fluidized bed. Specifically, the mixing and segregation behaviour of particle systems consisting of binary mixtures of glass beads (density of 2462 kg/m³ and size of 116 μm) and polyethylene particles (density of 939 kg/m³ and 234, 278, 328 μm in size) were examined. Simulations were carried out under hydrodynamic conditions pertinent to the fuel reactor of a cold flow model of a 10 kWth chemical looping combustion system. The particles motion was modelled by discrete element model (DEM) whilst the gas flow field was solved using the computational fluid dynamics (CFD) method. A two-way coupling algorithm was applied to take into account gas-particle interactions. The influence of boundary conditions and the sensitivity of domain size were tested. The model was then used to examine effects of the superficial gas velocity on the mixing/segregation behaviour of particles in terms of mixing index. The results showed that small domain sizes (i.e. with the width of the 2D domain size being a quarter of the fluidized bed diameter) can be used effectively in combination with the periodic boundary conditions to capture the overall mixing and segregation behaviour of binary system of particles in a large scale fluidized bed system. Also it was demonstrated that the domain size has minor influence on simulation results when using periodic boundary conditions. Moreover increasing the size of polyethylene particles in the binary mixture was found to decrease the mixing index resulting in poor mixing. Finally simulation results were compared with the experimental data under bubbling fluidized bed conditions. A reasonable agreement between the experimental data and the model predictions of the mixing index was obtained.
- Subject
- CFD-DEM; two-way coupling; binary mixture; different sizes and densities; particle mixing and segregation; gas-solid fluidized bed
- Identifier
- http://hdl.handle.net/1959.13/1307167
- Identifier
- uon:21352
- Identifier
- ISBN:9788889677834
- Language
- eng
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