Against the actual situation of mixed coal combustion in thermal power plants

NO emission characteristics of the single and mixed coal combustion were investigated on a drop tube furnace. Moreover

the effects of the excess air ratio

CO_2 mass concentration

fuel ratio FC/V and temperature on NO emission characteristics were analyzed.The results show that

when the excess air ratio increased from 0.8 to 1.4

the NO emission of the selected coals increased while that of the CO decreased. A higher mass concentration of CO in the flue gas corresponds to a lower NO emission concentration. Co-firing the pulverized coals can improve the pollutant emission characteristics. The NO emission concentration of the coal in O_2/CO_2 atmosphere is about 30%~40% lower than that in O_2/N_2 atmosphere.As the CO_2 mass concentration increased from 20% to 50%

the NO emission mass concentration of the selected coal decreased

while the CO emission mass concentration increased

and the magnitude of the changes are not large. With the increasing temperature

the NO emission mass concentration increased in both O_2/CO_2 atmosphere and O_2/N_2 atmosphere.At the same temperature and for the same kind of coal

the NO emission mass concentration in O_2/N_2 atmosphere is higher than that in O_2/CO_2 atmosphere. In different atmospheres and at different heating segments

the NO emission concentration curve changed with different slopes. At low and high temperatures

the NO emission concentration showed different trends with the increasing FC/V. At high temperatures

as the nitrogen content in the fuel increased

the NO emission concentration increased but the conversion rate declined.