Boiler supply water oxygenation process

Abstract

The invention discloses a boiler supply water oxygenation process. The phases of supply water oxygenation comprise a preliminary oxygenation phase and a later oxygenation phase; a transition point of the two phases is 12 months after beginning of supply water oxygenation; in the first month of the preliminary oxygenation phase, oxygen supply amounts at the outlet of a condensate polishing system and at the outlet of a deoxygenator are controlled in a range of 35 to 40 mu g / L and are then gradually reduced at an amplitude of 0.01 to 0.03% / month; in the later oxygenation phase, oxygen supply amounts at the outlet of the condensate polishing system and at the outlet of the deoxygenator are both controlled to be less than 30 mu g / L, a hydrogen amount at the inlet of the deoxygenator is stably controlled in a range of 0.2 to 0.4 mu g / L, and a hydrogen amount in main steam is stably controlled in a range of 0.4 to 0.8 mu g / L. The process provided by the invention can utmostly inhibit disadvantages of oxygenation on the basis of full usage of the advantages of oxygenation, effectively prevents tube explosion caused by falling of oxide skin and guarantees security, reliability and economical efficiency of boiler operation.

Description

technical field [0001] The invention relates to the technical field of boiler feedwater treatment, in particular to a boiler feedwater oxygenation treatment process. Background technique [0002] Under the anaerobic and high pH working conditions of boiler full volatile treatment, flow accelerated corrosion (FAC) is prone to occur in water supply and drainage systems, and the deposition rate of economizers and water walls is high. As a result, a series of problems have arisen, such as the rapid increase in pressure difference of the unit boiler due to scaling; high power consumption of the feed water pump; frequent blockage of the desuperheating water regulating valve and drain regulating valve; For this reason, a feed water oxygenation treatment process has been developed, that is, oxygen is added from the outlet of the condensed water treatment system and the outlet of the deaerator. Under the condition of flowing pure water, an appropriate amount of oxygen is used to form...

AI Technical Summary

Problems solved by technology

Its disadvantage is that the process controls the dissolved oxygen concentration in the main steam to ≤5μg / L in the constant oxidation stage, that is, controls the dissolved oxygen concentration in the main steam to a constant value of ≤5μg / L in the constant oxidation stage ( Control the oxygen addition amount at the outlet of the condensate treatment system at 50~1505μg / L, and at the same time control the oxygen addition amount at the feedwater pump inlet of the high pressure water supply system at 50~150μg / L), and in the constant oxidation stage with the system three The establishment of the protective film of ferric oxide will reduce the amount of oxygen consumed by the system, so in the late stage of constant oxidation conversion, it will cause excess oxygen, which will actually increase the amount of oxygen that reaches the high-temperature heating surface. In addition, the micro-oxygen operation in the process Reduce the oxygen addition amount of the high-pressure water system during the film replenishment stage so that the oxygen amount is only sufficient to repair and maintain the oxide film. The damage degree of the membrane is different from the oxidation state of the high-temperature heating surface, so the amount of oxygen required by the water supply system is different, which can easily cause insufficient or excessive oxygen addition in the high-pressure water system, which means that the process is not really effective. Precisely control the high temperature steam oxidation rate of the heating surface