Synergistic precise control device and method for automatic oxygen addition and ammonia addition for water supply in power plant

Abstract

A synergistic precise control device and method for automatic oxygen addition and ammonia addition for water supply in a power plant are disclosed. The device includes an automatic oxygen addition andammonia addition synergistic controller, a fed water oxygen addition system and a condensed water ammonia addition system, and mainly includes a PLC automatic oxygen addition and ammonia addition synergistic controller, an oxygen addition pressure reducing valve, an oxygen addition electromagnetic regulating valve, an oxygen addition pressure stabilizer, an ammonia addition metering pump, and other components. A fed water hydrogen conductivity signal is inputted to the PLC automatic oxygen addition and ammonia addition synergistic controller; when the fed water hydrogen conductivity is less than 0.15 [mu]S / cm, the appropriate oxygen amount and ammonia amount are controlled; when the fed water hydrogen conductivity is higher than 0.15 [mu]S / cm, an oxygen addition electric turn-off valve isturned off to stop oxygen addition and the ammonia amount is properly increased. Feedforward PID regulation is performed on oxygen addition according to a result of comparing a measured value of thedissolved oxygen content in fed water with a set value of the dissolved oxygen content by adopting a unit load as feedforward, thus achieving precise oxygen addition control. Feedforward PID regulation is performed on ammonia addition according to a result of comparing a measured value of conductivity of a deaerator inlet with a set value of the conductivity by adopting a unit load as feedforward,thus achieving precise ammonia addition control.

Description

technical field [0001] The invention relates to the technical field of chemical oxygenation and ammonia addition in a water vapor system of a power plant, in particular to a coordinated and precise control device and method for automatic oxygenation and ammonia addition to water supply. Background technique [0002] In order to suppress the corrosion of the water vapor system of the super (super) critical unit of the power plant and ensure the safe and stable operation of the unit, the super (super) critical unit usually adopts the synergistic treatment of oxygen addition and ammonia addition, in which the oxygen addition treatment is to prevent the formation and deposition of corrosion products, There are obvious advantages in prolonging the operating cycle of the mixed-bed hydrogen type in the finishing treatment. [0003] Oxygen in the thermal system water has a dual role, it is both a cathodic depolarizer and an anode passivator. When oxygen acts as a cathodic depolariz...

AI Technical Summary

Problems solved by technology

However, at present, when power plants should add oxygen and when should ammonia be added, how to control the amount of oxygen and ammonia added depends on manual adjustment, and it is impossible to achieve coordinated control to achieve the optimal control effect

[0004] Due to various reasons, the water vapor quality of the power plant changes and does not meet the oxygen addition conditions. If the operator cannot stop the oxygen addition in time and increase the ammonia addition amount, it will lead to the reaction of accelerating the corrosion of the water vapor system. When the water vapor quality of the unit is qualified At the same time, if you continue to use the oxidative full-volatility treatment method of only adding ammonia, it will also be detrimental to the safety and economy of the unit.

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