In view of the inaccurate ammonia spray amount and large delay problems occured during operation of SCR denitrification control systems

the main factor affecting the ammonia spraying amount control are analyzed.The main influence factors are determined by leading factor analysis on NOxconcentration at the SCR reactor entrance.On this basis

the prediction model of NOxformation at the SCR reactor entrance was established and introduced into the ammonia spraying flow control system.The practical engineering application shows that

the operating parameters determined by the leading factor analysis can predict the change of NOxconcentration

and the ameliorated control system can effectively improve the control characteristics of the SCR denitrification system.The NOxconcentration at the SCR reactor outlet is still in good control effect when the NOxconcentration at the SCR reactor entrance has a large fluctuation.