Axial Concentration Profiles and NO Flue Gas in a Pilot-Scale Bubbling Fluidized Bed Coal Combustor
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- 作者：Luí ; s A. C. Tarelho ; Manuel A. A. Matos ; and Fernando J. M. A. Pereira
- 刊名：Energy & Fuels
- 出版年：2004
- 出版时间：November 2004
- 年：2004
- 卷：18
- 期：6
- 页码：1615 - 1624
- 全文大小：1029K
- 年卷期：v.18,no.6(November 2004)
- ISSN：1520-5029
文摘
Atmospheric bubbling fluidized bed coal combustion of a bituminous coal and anthracite withparticle diameters in the range 500-4000 
m was investigated in a pilot-plant facility. Theexperiments were conducted at steady-state conditions using three excess air levels (10, 25, and50%) and bed temperatures in the 750-900 
C range. Combustion air was staged, with primaryair accounting for 100, 80, and 60% of total combustion air. For both types of coal, high NOconcentrations were found inside the bed. In general, the NO concentration decreased monotonically along the freeboard and toward the exit flue; however, during combustion with high airstaging and low to moderate excess air, a significant additional NO formation occurred near thesecondary air injection point. The results show that the bed temperature increase does not affectthe NO flue gas concentration significantly. There is a positive correlation between excess airand the NO flue gas concentration. The air staging operation is very effective in lowering theNO flue gas, but there is a limit for the first stage stoichiometry below which the NO flue gasstarts rising again. This effect could be related with the coal rank.
m was investigated in a pilot-plant facility. Theexperiments were conducted at steady-state conditions using three excess air levels (10, 25, and50%) and bed temperatures in the 750-900 C range. Combustion air was staged, with primaryair accounting for 100, 80, and 60% of total combustion air. For both types of coal, high NOconcentrations were found inside the bed. In general, the NO concentration decreased monotonically along the freeboard and toward the exit flue; however, during combustion with high airstaging and low to moderate excess air, a significant additional NO formation occurred near thesecondary air injection point. The results show that the bed temperature increase does not affectthe NO flue gas concentration significantly. There is a positive correlation between excess airand the NO flue gas concentration. The air staging operation is very effective in lowering theNO flue gas, but there is a limit for the first stage stoichiometry below which the NO flue gasstarts rising again. This effect could be related with the coal rank.