Hydrodynamic Characteristics of a Pilot-Scale Dual Fluidized Bed with Continuous Feeding and Discharging of Solids: Experiment and 3D Simulation

Zou, Zheng; Du, Zhan; Shao, Guoqiang; Liu, Qi; Xie, Zhaohui; Li, Hongzhong; Zhu, Qingshan

doi:10.1021/acs.iecr.9b02062

Cited by 5 publications

(1 citation statement)

References 56 publications

(89 reference statements)

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“…Likewise, Luo et al 22 carried out experiments and simulations on a pilot‐scale DFBG system to study the influence of solid inventory on the system hydrodynamics. Concerning this issue, Zou et al 23 analyzed the hydrodynamics and the loop‐seal characteristics of a DFB cold flow system with continuous feeding and discharging of solids by conducting both experiments and three‐dimensional (3D) computational fluid dynamics (CFD) simulation. Investigations of pressure profiles, solids recirculation flux, and gas leakage were conducted by Liu et al 24 to evaluate the hydrodynamic possibility of a DFB CFM.…”

Section: Introductionmentioning

confidence: 99%

Effect of sand particle size on the hydrodynamics of a dual fluidized bed cold flow system applied for waste‐to‐energy gasifiers

Dinh

Hsiau

et al. 2022

Intl J of Energy Research

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Summary Since the dual fluidized bed (DFB) system has been increasingly adopted for waste‐to‐energy gasification, a three‐dimensional computational fluid dynamics full‐loop model of a DFB cold flow system has been developed to predict the pressure and sand circulation rate (SCR) under various operating conditions. The pressure data were recorded at 18 specified points along the system height. In addition, the SCRs were determined at the two crucial positions connecting the riser and the gasifier and vice versa. The simulation results were then validated against the experimental data, taking into account the effects of the sand particle size (ds), the air inlet velocity in the riser (v0,riser), and the initial gasifier bed height (h0,gasifier). It could be observed in the riser that the flow structures of the smaller ds(s) were almost scattering patterns, while those of the bigger ones were mainly clusters. Compared with bigger ds(s), more homogeneous pressure distributions in the riser and higher bed expansion in the gasifier were obtained with smaller ones. A compromise between the system performance and pre‐treating cost for the feedstock particle sizes should be considered further to achieve the best system performance. On the other hand, the increases of the v0,riser and the h0,gasifier enhanced the gasifier bed pressure, facilitating the downward sand flow back to the riser via the LLS. Although some minor discrepancies existed between the simulation and experimental data, the predicted tendencies agreed well with the measured ones. It was also found that a system operating with ds = 500 μm, at v0,riser = 4.0 m/s and h0,gasifier = 0.25 m yielded stable flow characteristics and optimal global SCR. Moreover, some unexpected phenomena predicted and verified with the experimental observations could be avoided or minimized using suitable particle sizes of the feedstock and operating parameters. In sum, the better validation results with lower errors than our previous study, the more reasonable air‐sand flow patterns, and the substantial predictions of undesirable problems are the significant improvements of this study, providing valuable information for effectively designing and operating the practical DFB hot flow systems. Novelty Statement This study developed a 3D computational fluid dynamics full‐loop model of a DFB cold flow system for predicting the pressure and sand circulation rates under various operating conditions of particle size, inlet velocity, and initial bed height. The better validation results against the experimental data, the more reasonable air‐sand flow patterns, and the substantial predictions of undesirable problems are the significant improvements of this study, providing helpful information for designing and operating the DFB hot flow gasifiers.

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Section: Introductionmentioning

confidence: 99%