Device and method for monitoring concentration of sulfur trioxide in coal-fired flue gas on line

Abstract

The invention relates to the field of monitoring of coal-fired flue gas pollutants and discloses a device and a method for monitoring the concentration of sulfur trioxide in coal-fired flue gas on line. The device is used for synchronously sampling the coal-fired flue gas in two paths; the first path of flue gas is filtered and then is directly introduced into a flue gas analyzer to analyze components of raw flue gas; the second path of flue gas is filtered and then is introduced into a reactor for storing solid salt particles to be subjected to chemical reaction to generate gas which has relatively stable properties and is easy to detect; then the gas is introduced into the flue gas analyzer to analyze components of the reacted flue gas; and finally, the concentration of the sulfur trioxide in the flue gas is calculated through comparing the difference of the components of the flue gas in the raw flue gas and the reacted flue gas. The device and the method have a simple principle; anda complicated sulfur trioxide sampling link is avoided through indirect measurement, the measurement period is greatly shortened and personal errors in a sample analysis process are reduced. Furthermore, the flue gas analyzer can be used for continuously measuring on line, so that continuous online monitoring of the sulfur trioxide can be realized through a simple computer function.

Description

technical field [0001] The invention relates to the technical field of monitoring coal-burning flue gas pollutants, in particular to an on-line monitoring device and method for sulfur trioxide concentration in coal-burning flue gas. Background technique [0002] Sulfur trioxide (SO 3 ) mainly comes from two aspects: on the one hand, part of the sulfur dioxide (SO 2 ) will be further oxidized to generate SO 3 . On the other hand, in order to control nitrogen oxides (NO x ) emissions, most power plants are now equipped with selective catalytic reduction (SCR) denitrification systems, and the catalysts used in SCR denitrification systems are used to reduce NO x At the same time, it will also catalyze the oxidation of part of SO 2 Generate SO 3 . Some studies have shown that after the SCR denitrification system, the SO in the flue gas 3 content will be doubled. [0003] With the flue gas flow, the SO in the flue gas 3 reacts with water vapor to form sulfuric acid (H 2...

AI Technical Summary

Problems solved by technology

The above methods all need to take samples first and then measure, which has the disadvantages of long measurement period, complicated equipment and process, and large human error.

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