The Study Of The Technologies Of Hybrid SMCR/SCR Used On410t/h Power Plant Boiler

Pollutant NOx emission is an increasing threat to environment and human health, which becomes an urgent problem to be solved. Coal combustion in power plant is a major source of NOx. Many control methods have emerged as the times require for solving the NOx emission problem. One of these is hybrid selective non-catalytic reduction/selective catalytic reduction (SNCR/SCR). To achieve a NOx emission rate of≤50mg/m3(NH3slip rate of≤5ppm) which is less than the guide line of the government,the410t/h boiler of one power plant have been modified with the technologies of hybrid SNCR/SCR prior to the installation of the combustion modifications.This paper focuses on a series of study of the modification. First the innovation suggestion that additionally reduce the NOx emission rate is bringed forward based on the testing that demonstrate the SNCR. system’s ability to reduce NOx emissions. According to the core of the subject, the innovation scheme that homogenize the composition of the flue gas to promote optimal ammonia utilization and NOx reduction across the relatively small SCR catalyst through high speed steam is seted up based on a study about the homogenization of NH3in the flue gas. NOx emission experiment is conducted after innovation to analyze the effect of such factors as injection of urea reburning coal rate, steam disturbance and coal pulverizer operation mode on NOx emission,and the regulation proposals to control NOx emission are mentioned. A elementary study aiming at the effect on the equipments located just downstream of the SCR,ESP and FGD is carried out also. Finally,base on above work, further work on the hybrid NOx control system for reduced NOx emissions are also presented.