The conversion of fuel-N to NOx is the main contribution of modelling problem arising from coal combustion. This paper NOx from coal-fired industrial boilers and is the least-studied summarises the current understandi...The conversion of fuel-N to NOx is the main contribution of modelling problem arising from coal combustion. This paper NOx from coal-fired industrial boilers and is the least-studied summarises the current understanding of the mechanisms that account for the formation of NOx from fuel-N during coal combustion. Further experimentation on NOx emissions during bi- tuminous coal combustion was simulated with attention focused on the contribution of char-N and votatile-N to fuel-NOx through the Coal/Char combustion method. The critical analysis of this issue allowed for the identification of uncertainties and produced well-founded conclusions. The results indicated that fuel-NOx formation was a very complex physical-chemical pro- cess involving many competing mechanisms. These mechanisms included chemical reactions, convective mass transfer, heat transfer, adsorption and desorption. The contribution of char-N in this experiment varied between 30% and 70%. There may be a slight question as to the exact identity of the main contributor to fuel-NOx, and no definitive conclusion can be made as of yet This uncertainty is because the contribution of char-N to fuel-NOx was heavily affected by the combustion conditions and the contribution of char-N increased monotonically as temperature increased. There was a critical point in the relationship between particle size, air flow, 02 concentration and the contribution of char-N. The contribution of char-N increased with the increase of particle size and air flow initially when less than the critical value, and decreased when more than thecritical value. The contribution of char-N initially decreased when the 02 concentration was increased from 10% to 15% and increased more with the further increase in 02 concentration.展开更多
基金support was provided by Ministry of Environmental Protection of the People’s Republic of China (HBGY200709036)
文摘The conversion of fuel-N to NOx is the main contribution of modelling problem arising from coal combustion. This paper NOx from coal-fired industrial boilers and is the least-studied summarises the current understanding of the mechanisms that account for the formation of NOx from fuel-N during coal combustion. Further experimentation on NOx emissions during bi- tuminous coal combustion was simulated with attention focused on the contribution of char-N and votatile-N to fuel-NOx through the Coal/Char combustion method. The critical analysis of this issue allowed for the identification of uncertainties and produced well-founded conclusions. The results indicated that fuel-NOx formation was a very complex physical-chemical pro- cess involving many competing mechanisms. These mechanisms included chemical reactions, convective mass transfer, heat transfer, adsorption and desorption. The contribution of char-N in this experiment varied between 30% and 70%. There may be a slight question as to the exact identity of the main contributor to fuel-NOx, and no definitive conclusion can be made as of yet This uncertainty is because the contribution of char-N to fuel-NOx was heavily affected by the combustion conditions and the contribution of char-N increased monotonically as temperature increased. There was a critical point in the relationship between particle size, air flow, 02 concentration and the contribution of char-N. The contribution of char-N increased with the increase of particle size and air flow initially when less than the critical value, and decreased when more than thecritical value. The contribution of char-N initially decreased when the 02 concentration was increased from 10% to 15% and increased more with the further increase in 02 concentration.
