Prediction of air preheater blockage and optimized anti-clogging method of water injection and ammonia injection

Abstract

The invention discloses a method for predicting the blockage of an air preheater and optimizing the blockage prevention by spraying water and ammonia, comprising: (1) establishing the initial deposition temperature of ABS and SO2 3 Concentration and NH 3 Concentration product [SO 3 ]*[NH 3 ] associated database and NH 3 AS initial deposition temperature and SO in excess condition 3 Concentration [SO 3 ] associated database; (2) perform SO on the inlet of the air preheater in the actual power plant flue 3 with NH 3 concentration test; (3) the characteristic parameters of the flue gas to be tested [SO 3 ]*[NH 3 ], [SO 3 ] Compared with the established ABS and AS deposition temperature database, according to the corresponding mapping relationship, the initial deposition characteristic temperature of ABS and AS of the flue gas to be measured is obtained; (4) According to the predicted ABS deposition temperature, intelligently adjust the high-pressure water nozzle to At the corresponding position, spray water on the air preheater to prevent the air preheater from being blocked due to ABS deposition. The method is accurate, efficient, and low-cost, and can effectively solve the SO in coal-fired flue gas. 3 Air preheater ABS blockage caused by reaction with fugitive ammonia.

Description

technical field [0001] The invention relates to the field of preventing blockage of a tail flue air preheater, and more particularly, to a method for predicting blockage of an air preheater and optimizing water spraying and ammonia spraying. Background technique [0002] The coal used in coal-fired power plants usually contains a certain amount of S element, which is mainly converted into SO during the combustion process of the boiler 2 , accompanied by 1-2% SO 2 further oxidized to SO 3 . In the tail gas treatment process, selective catalytic reduction denitrification (SCR) is widely used. SCR process will have SO about 0.5-2% 2 Further catalytic oxidation to SO by V / W / Ti catalyst 3 . SO 3 Very active, SO 3 It will react with the fugitive ammonia in the flue gas to generate ammonium bisulfate (ABS) and ammonium sulfate (AS) and other substances. [0003] Among them, ammonium hydrogen sulfate is liquid in the air preheater temperature range, very viscous, and will d...

AI Technical Summary

Problems solved by technology

The existing technology mainly uses electric heat to decompose ammonia bisulfate, which requires a large number of electric wires to be arranged on the corrugated plate of the air preheater. The actual operation process consumes a lot of power, and the temperature of the corrugated plate of the air preheater is increased, resulting in smoke in the air preheater. The temperature field of the gas changes accordingly, which may affect the normal operation of the unit

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