分别在1 000 MW和600 MW超临界机组直流锅炉给水系统进行了加氧处理工艺试验,考察给水低氧量(氧质量浓度＜ 30 μg/L)处理控制给水系统腐蚀的可行性.在给水系统钝化膜形成阶段和钝化膜形成后分别进行了给水低氧量处理试验,结果表明在钝化膜形成阶段应保持较高的给水加氧量;在钝化膜形成后,保持给水氧的质量浓度10～20 μg/L能够维持钝化膜长期稳定,使给水系统得到保护;为防止疏水系统管路腐蚀,给水采取低氧量处理时应将给水pH值控制在9.3以上,不宜再低.%The oxygenated treatment experiments are carried out in the high-pressure feedwater system of the once-through boilers for 1 000-MW and 600-MW supercritical units to study the feasibility of inhibiting corrosion in the feedwater system by low-oxygen treatment (oxygen mass concentration ＜30 μg/L). The low-oxygen feedwater treatment experiments are conducted for the feedwater system separately when and after the passivation film is formed,. The results show that the amount of oxygen added to the feedwater must be kept at a higher levelduring the passivation film formation. Once the passivation film comes out, it can stay long and stable with the oxygen mass concentration ranging between 10 and 20 μg/L for the protection of the feedwater system. Aiming at inhibiting the corrosion of draining systems, the pH value of the feedwater should be maintained above 9.3 when the low-oxygen treatment is applied.
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