Ultra-low emission reconstruct of denitrification system based on NO_x uniformity test of SCR reactor
LI Tong;Datang Northeast Electric Power Test & Research Institute;
A 350 MW thermal power unit in northeastern China is taken as the research object, and the performance of the SCR reactor of denitrification system after ultra-low emission reconstruct is tested. Using the data obtained by drawing contour lines and line graphs, the distribution characteristics of outlet and inlet flue gas flow and NO_x concentration field of SCR reactor were studied and analyzed. The results shows that the average efficiency of the denitration system is 97.37%, and the average NO_x concentration at the outlet of the SCR reactor is 13.31 mg·m~(-3),which has reached the design requirement(efficiency ≥91.1%, outlet concentration ≤40 mg·m~(-3)), and the overall denitrification performance is pretty good. It is known from the results that the uniformity of the inlet NO_x concentration is good. the dispersion of NO_x,concentration at the outlet flue of the A and B side reactors were31.49% and 56.90%, which are more than the design value(≤15%), so the outlet NO_x distribution is uneven.This technical reconstruct makes the SCR reactor outlet NO_x concentration to meet the ultra-low emission limit requirements(≤50 mg·m~(-3)), but in the spray ammonia optimization adjustment, the ammonia injection grid cleaning and catalyst pressure control and other aspects of the existence of defects. On the basis of adding new catalyst layer,there is still room for improvement in the dredging of the catalyst layer, the automatic control of ammonia injection,the checking and modification of the flue gas flow field.
【CateGory Index】： X773