Nuclear power plant secondary circuit thermodynamic system ethanolamine and ammonia cooperative control method

Abstract

The invention belongs to the technical field of nuclear power plant chemistry, and particularly relates to a nuclear power plant secondary circuit thermodynamic system ethanolamine and ammonia cooperative control method. According to the method, an ethanolamine solution and an ammonia solution are added into a secondary circuit thermodynamic system to control the ethanolamine concentration and theammonia concentration in the main feed water of the secondary circuit thermodynamic system in a coordinated manner, so that the requirement that the pH value of the secondary circuit thermodynamic system is controlled to be 9.60-9.80 is met, wherein the concentration of ethanolamine in the main feed water is 1-2.5 mg / kg, and the ammonia concentration in the main feed water is 5-1.5 mg / kg. According to the invention, after the method is implemented, the pH value of the whole secondary circuit thermodynamic system is controlled to be 9.60-9.80, the iron content of the secondary circuit is obviously reduced, the iron content of the main feed water is reduced by about 30%, the hydrophobic iron content of the steam-water separation reheater is reduced by about 87%, and the amount of sludge flushed out from the secondary side of the steam generator is reduced by about 35%, so that the effect is remarkable.

Description

technical field [0001] The invention belongs to the technical field of nuclear power plant chemistry, and in particular relates to a method for synergistic control of ethanolamine and ammonia in a secondary circuit thermal system of a nuclear power plant. Background technique [0002] Steam generator (SG) is one of the important core equipment of nuclear power plant, and it is also the pressure boundary of the primary circuit. The integrity of the steam generator heat transfer tube is directly related to the safety of nuclear power plant operation. Statistics show that most of the failures of steam generators in nuclear power plants are related to the damage and cracking of heat transfer tubes, and more than 80% of the damage and cracking of heat transfer tubes are caused by corrosion. Corrosion often occurs in the stagnation area of ​​the steam generator with sludge deposits, and the sludge deposits in the steam generator mainly come from the corrosion of the thermal system...

AI Technical Summary

Problems solved by technology

Due to the small vapor-liquid partition coefficient of ethanolamine, it tends to be distributed in the liquid phase when used. Using ethanolamine alone cannot balance the pH control of the secondary loop thermal system, and at the same time, the concentration of ethanolamine in SG sewage will also increase significantly. For the design For power plants with continuous operation of the desalting bed of the steam generator blowdown system, the operating burden of the desalting bed is greatly increased; in addition, because ethanolamine is heated and decomposed to produce a small amount of organic acid, the overall conductivity of the second loop of ethanolamine is increased, affecting The positive conductivity control of the secondary circuit thermal system causes great interference to the judgment of condenser seawater leakage and the judgment of other anion impurities entering the secondary circuit and steam generator