The selective non-catalytic reduction(SNCR) denitrification system in waste incinerator unit has the characteristics of large delay and large inertia

and poor stability of denitration control caused by complex changes in characteristics and composition of waste as well as large fluctuation of combustion conditions. To solve these problems

automatic control strategy of the SNCR denitrification system based on intelligent feedforward is designed. Based on the cascade PID control

this control strategy adopts the intelligent feedforward structure which combines the model prediction feedforward based on partial least squares(PLS) with the key variable feedforward

and uses the model prediction error self-correction method to ensure the accuracy and stability of model prediction.The control strategy is applied to a 500 t/d waste incineration unit

and the application results show that

before the intelligent denitrification control system was put into service

the fluctuation of NO_x emission mass concentration was large. The relative standard deviation(RSD) of NO_x mass concentration within the statistics period was 19.81%

and the proportion of the instantaneous NO_x emission mass concentration less than 150 mg/m~3 was 95.62%. After the intelligent denitrification control system was put into service

the RSD of NO_x mass concentration within the statistics period was 12.40%

and the proportion of the instantaneous NO_x emission mass concentration less than 150 mg/m~3 was 99.31%. The fluctuation of NO_x emission mass concentration reduced significantly

and the control stability was significantly improved. The average daily ammonia intake flow rate and the average total ammonia intake decreased by 38.81% and 38.82% in the statistical time

indicating the stable

economic and environmental protection operation of the SNCR denitrification system in waste incinerator were realized.