Extending the EMMS-bubbling model to fluidization of binary particle mixture: Parameter analysis and model validation

Ahmad, Nouman; Tong, Ying; Lu, Bona; Wang, Wei

doi:10.1016/j.ces.2019.02.016

Cited by 24 publications

(14 citation statements)

References 48 publications

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“… Gas‐solid drag modelling: The characteristics of particle clustering in the polydisperse flow are more complicated than those in the monodisperse flow with single particle size, which brings more difficulties in accurately describing the drag reduction caused by particle clusters. [ 41,42 ] Although some studies have developed the drag model for binary‐particle gas‐solid flow, [ 41,42 ] these models are not able to accurately describe the drag in industrial systems with wide and continuous particle‐size distribution. The kinetic theory of the polydisperse granular flow: In the Eulerian‐Eulerian numerical approach, the solid‐phase stress tensor is solved by the kinetic theory of the granular flow. [ 35,36 ] As the original theory was developed based on the monodisperse flow, some studies extended it to polydisperse flow conditions.…”

Section: Simulation Modelsmentioning

confidence: 99%

Numerical analysis of the operating characteristics of a large‐scale CFB coal‐gasification reactor with the QC‐EMMS drag model

Liu

Huo

et al. 2020

Can J Chem Eng

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The operating characteristics of a 60 m high industrial circulating fluidized bed (CFB) coal‐gasification reactor were investigated numerically based on the Eulerian‐Eulerian approach. The QC‐EMMS drag model was used to describe the gas‐solid drag reduction caused by particle clusters. The simulations predicted the overall characteristics of fluidization and gasification inside the CFB reactor riser. The simulated results are in agreement with measured data from the field test. Then, the numerical model was used to analyze the influences of the steam/coal ratio, pulverized coal‐particle size, and operating pressure. The results show that each of the three operating parameters has a great impact on different performance parameters, such as the solid mass circulation rate, the H2/CO ratio, the effective syngas yield, and the average bed temperature. The predicted data were then correlated to provide supports for optimizing the operations of large‐scale CFB coal gasifiers.

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Section: Simulation Modelsmentioning

confidence: 99%

Numerical analysis of the operating characteristics of a large‐scale CFB coal‐gasification reactor with the QC‐EMMS drag model

Liu

Huo

et al. 2020

Can J Chem Eng

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“…However, modeling of this multi-phase interactive structure is a challenging problem that even the complex-algorithm Computational Fluid Dynamics (CFD) models do not give the exact solution [1,2]. The evolution of these models is running continuously to touch mesoscopic aspects related to the complex nature of the real phenomenon [3][4][5]. However, the CFD models still require a long time and a high computation cost to carry out a comprehensive validation with various experimental cases.…”

Section: Introductionmentioning

confidence: 99%

A Conservative Macroscopic Model for Binary-mixture Fluidized Beds

Alagha

Szentannai

2021

Period. Polytech. Chem. Eng.

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Two approaches are commonly used for modeling the vertical mixing of binary-mixture fluidized beds, Computational Fluid Dynamics (CFD) and macroscopic modeling. A common realization of the latter one is the Gibiralo–Rowe (G-R) model, which uses the Two-Phase Theory. This macroscopic model obviously overperforms CFDs regarding computational cost; however, determining its coefficients is a still challenging issue. Although several methods were published for solving this, the general problem with most of them remains their neglecting the conservation of mass. In the present new procedure, the mass conservation is applied to correct the values of the G-R model coefficients estimated from known equations. The present model was validated on a wide variety of fluidized bed systems. The results show that this conservative and macroscopic model gives more accurate predictions than the recently published other macroscopic models, and this one is, in general, better than the CFD model from the perspective of prediction accuracy as well.

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“…[15][16][17][18][19][20][21][22][23][24][25] However, the sub-grid models applied for polydispersed bubbling gas-solid flow are still in their preliminary stages and there are still many problems to be settled in this area. [26][27][28][29][30] Structure-based drag models, which consider the influence of meso-scale structures on the inter-phase drag force within BFBs, have been considered as a potential means of simulating nonuniform monodispersed gassolid flow. [15][16][17]19] Recently, efforts have been made to extend structure-based drag models for monodispersed gas-solid systems to the polydispersed gas-solid systems.…”

Section: Introductionmentioning

confidence: 99%

“…Some researchers have made attempts to extend the energy minimization multi-scale (EMMS) drag model based on monodispersed gas-solid systems to compute the binary gas-solid systems. [26][27][28][29][30] Under the framework of the EMMS method, each phase contained two types of particles and surrounding fluidized media. The extended EMMS drag model enabled the pronounced movement of bubbles to be identified, and thus it predicts the segregation behaviour better than the conventional drag model.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Simulation of binary particle segregation for bubbling fluidized beds using polydispersed structure‐based drag model extended from a monodispersed model

Jia

Zou

et al. 2020

Can J Chem Eng

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A bubble structure‐based drag model developed for the monodispersed system has been extended to simulate bi‐dispersed bubbling fluidized beds. Both dense phase and dilute phase are considered to be comprised of two types of particles with different sizes. The derivation of the structure‐based drag coefficient for individual particle based on the force equilibrium principle is proved to be independent of the volume fractions (εsi) of particle i. The multi‐fluid model in the commercial software Ansys Fluent is employed to evaluate the polydispersed drag model for the segregation of binary gas‐particle flows in a bubbling fluidized bed. It is shown that the simulation results predicted by the new structure‐based drag model are in reasonable agreement with experimental data with a 6.34% root mean square error (RMSE). The new structure‐based model can capture the particle distribution at the top region of the fluidized bed well. The bubble behaviour can also be captured by the new model well.

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Extending the EMMS-bubbling model to fluidization of binary particle mixture: Parameter analysis and model validation

Cited by 24 publications

References 48 publications

Numerical analysis of the operating characteristics of a large‐scale CFB coal‐gasification reactor with the QC‐EMMS drag model

Numerical analysis of the operating characteristics of a large‐scale CFB coal‐gasification reactor with the QC‐EMMS drag model

A Conservative Macroscopic Model for Binary-mixture Fluidized Beds

Simulation of binary particle segregation for bubbling fluidized beds using polydispersed structure‐based drag model extended from a monodispersed model

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