Anti-corrosion and anti-scaling integrated control system and method for thermal equipment of power plant

Abstract

The invention discloses an anti-corrosion and anti-scaling integrated control system and method for thermal equipment of a power plant. According to the system, an economizer inlet pipeline is provided with an online conductivity meter, and a deaerator inlet, an economizer inlet and a high-pressure heater drainage pipeline are each provided with an online dissolved oxygen meter. When the measuredvalue of the economizer inlet on-line dissolved oxygen meter is lower than the lower limit of a set value or higher than the upper limit of the set value, a PLC increases or decreases the ammonia adding amount on the condensed water fine treatment outlet main pipe, and when the measured value of the economizer inlet on-line conductivity meter is lower than the lower limit of the set value or higher than the upper limit of the set value, the PLC increases or decreases the oxygen adding amount of feed water on a descending pipe of the deaerator, so that the dissolved oxygen and the direct conductivity at the economizer inlet are made to be within the optimal control range. And when the high-pressure heater hydrophobic dissolved oxygen is lower than the lower limit value or higher than the upper limit value, the PLC increases or decreases the oxygen adding amount on the high-pressure heater hydrophobic pipeline, so that the high-pressure heater hydrophobic oxygen content is made to be within the control range. And integrated control over corrosion prevention and scale prevention of the thermal equipment is achieved.

Description

technical field [0001] The invention relates to the field of anti-corrosion and anti-scaling of thermal equipment in a power plant, in particular to an integrated control system and control method for anti-corrosion and anti-scaling of thermal equipment in a power plant. Background technique [0002] At present, many units in power plants adopt AVT full volatilization treatment under the chemical water condition. By adding ammonia water, the pH value of the economizer inlet feed water is controlled above 9.2, and the carbon steel surface protective film Fe is reduced under the condition of hydrazine deoxidation. 3 o 4 Solubility, thereby inhibiting corrosion. But AVT operation has a big flaw. Ultra (super) critical unit, the feed water is fully volatilized, and the Fe formed on the metal surface 3 o 4 Loose protective film, high solubility, and poor protection lead to a series of problems, such as high iron content of corrosion products in water vapor, high fouling rate ...

AI Technical Summary

Problems solved by technology

Ultra (super) critical unit, the feed water is fully volatilized, and the Fe formed on the metal surface 3 o 4 Loose protective film, high solubility, and poor protection lead to a series of problems, such as high iron content of corrosion products in water vapor, high fouling rate of water wall, rapid rise of boiler pressure difference, blockage of water wall orifice and high drain regulating valve , The finishing operation cycle is short, the mixed bed regeneration is frequent, etc., which seriously affect the safety and economy of the unit operation

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