Full-loop study of a dual fluidized bed cold flow system: Hydrodynamic simulation and validation
| Autor: | Huy Nguyen, Cong Binh Dinh, Meng Yuan Tsai, Yi Shun Chen, Shu San Hsiau, Chien Yuan Su, Hou Peng Wan |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Wood gas generator
business.industry General Chemical Engineering Flow (psychology) 02 engineering and technology Mechanics Static pressure Computational fluid dynamics 010402 general chemistry 021001 nanoscience & nanotechnology Residual 01 natural sciences 0104 chemical sciences Volumetric flow rate Circulation (fluid dynamics) Mechanics of Materials Fluidized bed Environmental science 0210 nano-technology business |
| Zdroj: | Advanced Powder Technology. 32:670-682 |
| ISSN: | 0921-8831 |
| Popis: | The unsteady behaviors of the air-silica sand flow in a lab-scale dual fluidized bed gasification cold flow system have been studied. A two-dimensional computational fluid dynamics full-loop model with poly-size distribution in solid phases was developed as an innovation of this study to investigate the effects of crucial parameters on system hydrodynamics. The results showed a decrease in the mixture static pressure from the bottom to the upper regions of the system, which maintained the system operations stable. The riser air inlet velocity and the gasifier static bed height were found to play considerable roles in enhancing the total sand flow rates. The same tendencies in the prediction and experiment of both the mixture pressure and the sand flow rate showed the feasibility of the proposed model. Besides, the residual evaluation enhanced data reliability and supported model validation. Especially, undesirable phenomena possibly occurring in the system operation under improper conditions could also be predicted. Accordingly, the inventory of bed material and the fluidizing gas flow rates should be suitably regulated to maintain pressure balances, trouble-free continuous flow, optimal sand circulation rate, and low solids loss. Furthermore, the obtained results in this study can be used as a reference for optimizing the designs and operational conditions of large-scale plants. |
| Databáze: | OpenAIRE |
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