Ammonia spraying amount control method and system for selective catalytic reduction (SCR) flue gas denitration system

Abstract

The invention discloses an ammonia spraying amount control method and system for a selective catalytic reduction (SCR) flue gas denitration system. A hearth combustion NOx data model and a SCR reaction mechanism are combined, an ammonia spraying amount calculation model is established, model parameters are identified by operation data and the model parameters are adjusted timely, ammonia sprayingfeedforward amount is calculated through the and a control system is introduced, so that the ammonia spraying amount control quality is improved, and the adjusted instantaneity and accuracy of the ammonia spraying amount is guaranteed. When a continuous emission monitoring system (CEMS) is demarcated or purged, feedforward control weight is adjusted by a feedforward coefficient, meanwhile, the feedback effect is weakened, and thus the influence of the working condition change of the CEMS on the ammonia spraying amount control is avoided.

Description

technical field [0001] The invention relates to the technical field of selective catalytic reduction flue gas denitrification, in particular to an ammonia injection amount control method and system for an SCR flue gas denitrification system. Background technique [0002] Selective Catalytic Reduction (SCR) flue gas denitrification is a widely used denitrification technology, and the amount of ammonia injection is an important factor affecting its denitrification efficiency. Too little ammonia injection will lead to insufficient catalytic reduction reaction, resulting in non-compliance of flue gas emissions. Excessive ammonia injection will increase the amount of ammonia escape, causing secondary pollution to the environment, causing corrosion to downstream equipment, and increasing operating costs. SCR flue gas denitrification device such as figure 1 shown. [0003] With the large-scale operation of new energy units, thermal power units need to further improve their load ...

AI Technical Summary

Problems solved by technology

When the purging or calibration is completed, the NOx concentration at the inlet changes instantaneously. Because iterative optimization requires a certain calculation time, the amount of ammonia injection cannot be adjusted in time, which may easily cause excessive emissions or excessive ammonia injection.

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