超超临界参数下水分子本身具有很强的氧化性,能使锅炉水冷壁管形成致密坚固的垢.以某电厂2×600 MW超超临界机组化学清洗为例,根据锅炉垢样特性,选用了3种复合有机酸,进行静态、动态酸洗模拟试验,测定了不同配方下水冷壁的腐蚀速率,并按动态试验的结果确定了酸洗方案.最终选定了由2％羟基乙酸与0.5％氟化钠组成并添加缓蚀剂的复合有机酸进行化学清洗,腐蚀速率及腐蚀量皆符合标准,清洗效果良好.%Water molecules under ultra-supercritical conditions have strong oxidizing nature, which makes boiler water wall tubes form dense scale. Based on the analysis of the scale composition for the two 600-MW ultra-supercritical units at one power plant, the static and dynamic simulation tests are conducted with three sorts of organic acids. And the corrosion rate and corrosion quantity of the metal piece are determined respectively. Following the dynamic simulation test result, 2% glycolic acid and 0.5% sodium fluoride with a certain amount of inhibitor is chosen as the cleaning agent for the two units. After cleaning, both the corrosion rate and corrosion quantity meet the related standard, which indicates that the cleaning effect is satisfactory.
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