A guidance method for steam soot blowing optimization of boiler air preheater

Abstract

The invention discloses a steam soot blowing optimization guidance method of a boiler air preheater, which calculates the deposition coefficient of ammonium bisulfate according to flue gas parameters, and judges the deposition tendency of ammonium bisulfate; Calculate the resistance coefficient of the air preheater to reflect the dust accumulation and blockage of the air preheater; obtain the correlation between the resistance coefficient of the air preheater and the ammonium bisulfate deposition coefficient, and use the ammonium bisulfate deposition coefficient to predict the dust accumulation and blockage trend of the air preheater, so as to realize the active Prevent soot blowing. The steam soot blowing optimization guidance method of the boiler air preheater provided by the present invention changes the original fixed frequency soot blowing mode, uses the ammonium bisulfate deposition coefficient as the feedforward parameter of the soot blowing operation, predicts the soot accumulation trend of the air preheater, and realizes active prevention of blowing Ash, to ensure the economical and safe operation of the unit, and at the same time, the operation of steam soot blowing is more reasonable, which can save steam consumption to a certain extent.

Description

technical field [0001] The invention belongs to the technical field of a steam soot blowing method for a boiler air preheater, and in particular relates to an optimization guidance method for steam soot blowing of a boiler air preheater. Background technique [0002] There are three types of dust accumulation in the existing boiler air preheater: [0003] Loose ash deposition: when the flue gas is on the medium-low temperature heating surface, the gaseous alkali metal finishes the condensation process, and the ash particles turn from a molten state to a solid state. At this time, the ash deposit is less viscous and loose in structure, and is easy to remove by steam soot blowing; [0004] Acid condensation and ash deposition: when the flue gas temperature is lower than the acid dew point temperature, sulfuric acid vapor condenses and adheres to the fly ash on the heated surface wall, which is not easy to be removed by soot blowing, resulting in low-temperature corrosion and c...

AI Technical Summary

Problems solved by technology

[0007] With the completion of the denitrification transformation, the impact of sulfuric acid on the corrugated plate of the air preheater and the deposition of dust has been reduced, while the effect of ammonium bisulfate on the bonding and deposition of dust has become more and more obvious. When the monitoring value of the resistance of the flue gas side of the air preheater starts to rise, it means that the deposited ash has begun to accumulate and scale. With the increase of the running time, the resistance of the air preheater will increase rapidly, which will restrict the load capacity of the unit in severe cases.

[0008] figure 1 It is the change curve of the flue gas side pressure drop of the air preheater after the denitrification transformation of an existing coal-fired boiler: about 15 days after it was put into operation, the pressure drop of the flue gas side of the air preheater on the B side rose from 1.3kPa to 1.8kPa; on the 20th day, The pressure drop on the flue gas side has risen rapidly to 2.4kPa, indicating that once ammonium bisulfate is deposited and scaled, the resistance of the air preheater will increase rapidly, and steam soot blowing will no longer be effective at this time

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