To realize ultra-low emission

coal-fired flue gas denitration of seven power plant was reformed. The mixture of low NOxcombustion technology and post-furnace selective catalytic reduction technology was utilized for the denitration system

in which the combustor of pulverized coal boiler

SCR denitration system

and induced fan were designed and modified accordingly. Moreover

the effect of excess air coefficient

the reactor temperature and ammonia-nitrogen mole ratio on denitration efficiency was investigated. The experimental results showed that when the temperature was controlled at about 360 ℃

the excess air coefficient was between 0.9-1.0

the ammonia-nitrogen ratio was about 1.2

the comprehensive denitration efficien

cy of the SCR system of power plant could reach more than 90 %

and the NO

x

concentration in flue gas outlet was below 45 mg/Nm

3

and the outlet temperature of flue gas of about 250-280 ℃

in line with environmental protection department emission targets.