1. Investigation of Submodels in Computational Fluid Dynamics Simulations of a Large-Scale Pulverized-Coal-Fired Furnace: Significant Role of H2
- Author
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Kazuhiro Watanabe, Takamasa Ito, Toshiyuki Suda, Toshiro Fujimori, and Juwei Zhang
- Subjects
Baseline case ,Scale (ratio) ,Pulverized coal-fired boiler ,business.industry ,Chemistry ,020209 energy ,General Chemical Engineering ,Energy Engineering and Power Technology ,Coal combustion products ,02 engineering and technology ,Computational fluid dynamics ,Combustion ,Fuel Technology ,020401 chemical engineering ,0202 electrical engineering, electronic engineering, information engineering ,Char ,0204 chemical engineering ,business ,Process engineering - Abstract
Certain simplified submodels of coal combustion, whose precision can be inadequate for certain situations, are widely used in computational fluid dynamics (CFD) simulations of a pulverized-coal-fired furnace. A large-scale furnace was simulated to explore the effects of certain advanced submodels. Comparing the simulation results in four cases to different submodels shows that the ignitability of burners is closely linked to the amount of H2 generated. In the baseline case, which disregards H2, we obtained very poor ignitability for all burners. Using a four-step mechanism instead of a two-step mechanism for volatile combustion and considering the char gasification (C–H2O) and detailed composition of volatiles are all clearly likely to improve ignitability. Meanwhile, superior ignitability also increases the heat absorbed by walls, reduces gas temperatures at the furnace exit, and reduces CO in the furnace. CO can also be increased by accounting for char gasification (C–CO2) and the detailed composition o...
- Published
- 2016
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