火电厂锅炉管道金属内壁氧化膜的影响因素研究  

Research on the Characteristics of Metal Oxide Film on Piping Inner Walls of Power Plant Boilers

作　　者：黄万启[1] 李志刚[1] 张洪博[1] 曹松彦[1] 

机构地区：[1]西安热工研究院有限公司,陕西西安710032

出　　处：《中国电力》2013年第7期6-10,17,共6页Electric Power

摘　　要：研究给水加氧处理前后锅炉管壁金属氧化膜生成情况,以确定不同温度范围内金属氧化膜的主要影响因素。分析和比较了给水全挥发处理(AVT)工况和加氧处理(OT)工况下,省煤器和水冷壁管氧化膜的特点;通过试验台和现场研究数据,探讨了锅炉高温段氧化皮生成与剥离的成因。研究结果表明,纯水中加入的氧气使热力系统低温段(300℃以内)金属表面生成了具有保护作用的棕红色Fe2O3膜,这层Fe2O3膜需要连续供氧维持其稳定性;锅炉高温段受热面中18铬系列奥氏体不锈钢氧化皮剥落原因较为复杂,温度和材料本身应是主要影响因素。The formation of oxidation film on boiler tubes before and after oxygenation treatment （OT） is studied to figure out the major factors contributing to the metal surface oxide film within different temperature ranges. The characteristics of the oxide film on the economizer and water wall tubes are analyzed and compared under the conditions of feedwater all-volatile （reduction/oxidation） treatment-（AVT（R）/AVT（O）） and oxygenation treatment. The causes of metal oxidation and scale exfoliation in the high-temperature section of boilers are also explored with the data from both test bench and field testing. The results show that feeding oxygen to the water makes the metal surface form a redish brown Fe2O3coating layer in the low-temperature section of the thermal system（under 300℃）, and this layer requires continuous oxygen feeding to maintain its stability. The causes of scale exfoliation of 18Cr austenitic stainless steel in high-temperature sections are complex. Nevertheless, the temperature and the material itself are believed to be the major culprits.

关 键 词：锅炉管道 金属氧化膜 给水加氧处理 γ-Fe2O3膜 α-Fe2O3膜 氧化皮剥落 

分 类 号：TK224.9[动力工程及工程热物理—动力机械及工程] TM621.8[电气工程—电力系统及自动化]