Yancong Liu - Academia.edu (original) (raw)
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Papers by Yancong Liu
Powder Technology, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Processes, 2020
The difference of gas-solids flow between a circulating fluidized bed (CFB) downer and riser was ... more The difference of gas-solids flow between a circulating fluidized bed (CFB) downer and riser was compared by computational particle fluid dynamics (CPFD) approach. The comparison was conducted under the same operating conditions. Simulation results demonstrated that the downer showed much more uniform solids holdup and solids velocity distribution compared with the riser. The radial non-uniformity index of the solids holdup in the riser was over 10 times than that in the downer. In addition, small clusters tended to be present in the whole downer, large clusters tended to be present near the wall in riser. It was found that the different cluster behavior is important in determining the different flow behaviors of solids in the downer and riser. While the particle residence time increased evenly along the downward direction in the downer, particles with both shorter and longer residence time were predicted in the whole riser. The nearly vertical cumulative residence time distribution...
Powder Technology, 2019
The interactions of gas and solids are important in determining the flow structures in the Circul... more The interactions of gas and solids are important in determining the flow structures in the Circulating Fluidized Bed (CFB) downer. Proper description of the interphase drag model is thus crucial for simulating the downer. Considering that cluster with several numbers of particles can be present in the downer, an interphase drag model was developed by considering the dynamic equilibrium of the amount of particles in and out of the cluster in the downer, which was then incorporated into the Computational Particle Fluid Dynamics (CPFD) model. CPFD simulation results show that the predicted particle flow behaviors are in good agreements with experimental data under different operating conditions. Solids circulation rate and gas velocity can significantly affect particle flow behaviors especially in the acceleration region near the inlet. More amounts of particles flow faster in the center while a few part of particles flow slower near the wall, resulting that the particle residence time is shorter and uniform in the center and longer near the wall. The residence time distribution (RTD) curve of particles is narrower with a higher peak in the downer than in the riser. Simulation results indicate that less back-mixing of particles is present in the downer, and the flow structure in the downer approximates the ideal plug flow. The present method considering the cluster effect is reasonable in predicting the flow behavior and RTD of particles in the downer.
Powder Technology, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Processes, 2020
The difference of gas-solids flow between a circulating fluidized bed (CFB) downer and riser was ... more The difference of gas-solids flow between a circulating fluidized bed (CFB) downer and riser was compared by computational particle fluid dynamics (CPFD) approach. The comparison was conducted under the same operating conditions. Simulation results demonstrated that the downer showed much more uniform solids holdup and solids velocity distribution compared with the riser. The radial non-uniformity index of the solids holdup in the riser was over 10 times than that in the downer. In addition, small clusters tended to be present in the whole downer, large clusters tended to be present near the wall in riser. It was found that the different cluster behavior is important in determining the different flow behaviors of solids in the downer and riser. While the particle residence time increased evenly along the downward direction in the downer, particles with both shorter and longer residence time were predicted in the whole riser. The nearly vertical cumulative residence time distribution...
Powder Technology, 2019
The interactions of gas and solids are important in determining the flow structures in the Circul... more The interactions of gas and solids are important in determining the flow structures in the Circulating Fluidized Bed (CFB) downer. Proper description of the interphase drag model is thus crucial for simulating the downer. Considering that cluster with several numbers of particles can be present in the downer, an interphase drag model was developed by considering the dynamic equilibrium of the amount of particles in and out of the cluster in the downer, which was then incorporated into the Computational Particle Fluid Dynamics (CPFD) model. CPFD simulation results show that the predicted particle flow behaviors are in good agreements with experimental data under different operating conditions. Solids circulation rate and gas velocity can significantly affect particle flow behaviors especially in the acceleration region near the inlet. More amounts of particles flow faster in the center while a few part of particles flow slower near the wall, resulting that the particle residence time is shorter and uniform in the center and longer near the wall. The residence time distribution (RTD) curve of particles is narrower with a higher peak in the downer than in the riser. Simulation results indicate that less back-mixing of particles is present in the downer, and the flow structure in the downer approximates the ideal plug flow. The present method considering the cluster effect is reasonable in predicting the flow behavior and RTD of particles in the downer.