An evaluation of the efficacy of various coal combustion models for predicting char burnout [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 662 Technology of explosives, fuels, related products
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. National Nuclear Security Administration ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2016
• Mô tả vật lý: Size: p. 53-64 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 267773
• Chủ đề: 1. 01 coal, lignite, and peat; 2. �char oxidation; 3. �coal; 4. Combustion; 5. �simulation

Tóm tắt

 Coal combustion is comprised of several subprocesses including devolatilization and heterogeneous reactions of the coal char with O<
 sub>
 2<
 /sub>
 , CO<
 sub>
 2<
 /sub>
 , H<
 sub>
 2<
 /sub>
 O and potentially several other species. Much effort has been put forth to develop models for these processes which vary widely in both complexity and computational cost. This work investigates the efficacy of models for devolatilization and char reactions at either end of the complexity and cost spectrums for a range of particle sizes and furnace temperatures and across coal types. The overlap of simulated devolatilization and char consumption is also examined. In the gas phase, a detailed kinetics model based on a reduced version of the GRI 3.0 mechanism is used. The Char Conversion Kinetics and an�n<
 sup>
 th<
 /sup>
 -order Langmuir-Hinshelwood models are considered for char oxidation. The Chemical Percolation and Devolatilization and a two-step model are considered for devolatilization. Results indicate that high-fidelity models perform better at representing particle temperature and mass data across a wide range of O<
 sub>
 2<
 /sub>
 �concentrations as well as coal types. A significant overlap in devolatilization and char consumption is observed for both char chemistry and devolatilization models.