A generalized drag Law for heterogeneous gas-solid flows in fluidized beds

Dai, Qi; Chen, Cheng; Qi, Haiying

doi:10.1016/j.powtec.2015.05.030

Cited by 15 publications

(9 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Then, H D was used in the simulation to include the drag reduction caused by the particle clusters. [ 32–34 ]…”

Section: Simulation Modelsmentioning

confidence: 99%

“…The QC‐EMMS drag model was used to calculate H D in this study. [ 32–34 ] The model introduced a sub‐model for the cluster solid holdup, ε sc , into the EMMS equations. [ 32 ] The ε sc sub‐model can be seen as follows:

ε_{sc} = ε_{s} + normalΨ \frac{211.74 {ε_{s}}^{2}}{e^{{((), 3.098 ε_{s} + 0.9398)}^{2}} - 2.42} ((), ε_{s, italicmf} - ε_{s})

…”

Section: Simulation Modelsmentioning

confidence: 99%

“…[ 32 ] The predicted results were more consistent with experimental data than those predicted by the conventional homogeneous drag model. [ 32–34 ] Therefore, the QC‐EMMS model should be used in such work in order to enhance simulation accuracy. Its adaptability should also be further examined as to simulations for various gasification conditions.…”

Section: Introductionmentioning

confidence: 99%

“…[ 30 ] Among these models, the QC‐EMMS drag model, based on energy‐minimization multi‐scale (EMMS) theory, exhibits high accuracy and wide applicability. [ 31–34 ] The model accurately reproduced the heterogeneous flow states caused by the particle clusters. [ 32 ] The predicted results were more consistent with experimental data than those predicted by the conventional homogeneous drag model.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Self Cite

View full text Add to dashboard Cite

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.

show abstract

“…Then, H D was used in the simulation to include the drag reduction caused by the particle clusters. [ 32–34 ]…”

Section: Simulation Modelsmentioning

confidence: 99%

ε_{sc} = ε_{s} + normalΨ \frac{211.74 {ε_{s}}^{2}}{e^{{((), 3.098 ε_{s} + 0.9398)}^{2}} - 2.42} ((), ε_{s, italicmf} - ε_{s})

…”

Section: Simulation Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Self Cite

View full text Add to dashboard Cite

show abstract

“…Numerical simulation has been extensively used to study the internal flow and reaction states in a coal gasifier, and it is an effective way to predict the load characteristics. − Some numerical studies have reported the variations of gasification parameters such as carbon conversion and effective syngas yield with the load in the burner gasifier where the gas–solid flow is dilute. − However, in a dense gas–solid flow of the CFB gasifier, load change brings more challenges to the modeling of flow and reaction processes in the reactors. The change of load will seriously affect the properties of the gas in the reactor, thus influencing the structure of heterogeneous particle clusters in CFB − and then the reduction of momentum transfer between particles and gas, i.e., gas–solid drag. , The drag reduction will surely affect the simulation accuracy of fluidization and then the reaction processes. Hence, the drag model used in simulations is required for a high generalization capability to ensure the drag calculation accuracy under different load conditions.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of Load Characteristics of a CFB Coal Gasifier by Using the Generalized Drag Model

Huo

Liu

et al. 2020

Energy Fuels

Self Cite

View full text Add to dashboard Cite

The load characteristics of a large circulating fluidized bed (CFB) coal gasifier were simulated by using the Eulerian− Eulerian method with the generalized drag model, QC-EMMS. The simulations predicted the gas−solid two-phase flows and coal gasification in a 60 m high CFB gasifier for 50, 80, and 100% loads. The results show that the simulated pressure drop, temperatures, and syngas compositions at the 50% load agree well with the field test data. The solid mass circulation rate and the H 2 /CO ratio then increase linearly with the increasing load. The average temperature in the riser decreases slightly by 4% with the increasing load. The yield of effective syngas per ton coal stabilizes at 465 Nm 3 /t for loads over 80%. The study verifies that the QC-EMMS drag model can be used to accurately simulate the complicated gas−solid reaction processes in a large industrial CFB.

show abstract

Continuum theory for dense gas-solid flow: A state-of-the-art review

Wang

2020

Chemical Engineering Science

249

View full text Add to dashboard Cite

A generalized drag Law for heterogeneous gas-solid flows in fluidized beds

Cited by 15 publications

References 13 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

Numerical Study of Load Characteristics of a CFB Coal Gasifier by Using the Generalized Drag Model

Continuum theory for dense gas-solid flow: A state-of-the-art review

Contact Info

Product

Resources

About