摘要
为预防日益严重的锅炉水冷壁高温腐蚀,在300 MW燃煤锅炉上研究了近壁面气氛分布规律,结合不同气氛下水冷壁材料12Cr1Mo V的高温腐蚀动力学试验数据,预测了不同温度、气氛、腐蚀层开裂周期下的高温腐蚀速率,从而提出不同运行时间下锅炉水冷壁腐蚀的倾向判断标准;建立了腐蚀速率与H_2S浓度、腐蚀时间和腐蚀层开裂周期的关系式,并以腐蚀膜开裂周期12 h和24 h为例,求得了近壁面气氛的许用浓度。研究结果表明,近壁面硫化氢(H_2S)浓度与一氧化碳(CO)浓度成正比,而与氧气(O_2)浓度成反比;高温腐蚀速率与时间符合抛物线关系,与温度符合阿雷尼乌斯定律;只要将近壁面气氛控制在对应的H_2S许用浓度范围以内,就可以预防严重高温腐蚀的发生。
To prevent the increasingly serious problems of high temperature corrosion of water walls in boilers,the research on the distribution of the near wall atmosphere is carried out in a 300MW boiler.With the test data of high temperature corrosion kinetics of the water wall materials 12Cr1MoV,the corrosion rate under different temperature,atmosphere and cracking period of corrosion layer is forecasted such that the corrosion tendency standard of water walls in boilers at different running time is put forward.The relationship between the corrosion rate and the H2S concentration,the corrosion time and the cracking period of the corrosion film is established,and the limiting concentration of atmosphere near walls is obtained with the cracking period of 24 h and 48 h as examples.The results show that the concentration of H2S near walls is proportional to the concentration of CO,but inversely proportional with the concentration of O2.The high temperature corrosion rate change with time follows the parabolic law,while the change with temperature complies with the Arrhenius law.and the change with H2S concentration follows the exponential law.As long as the atmosphere near walls is controlled within the limiting concentration range,the serious high temperature corrosion could be prevented.
作者
许伟刚
谭厚章
刘原一
魏博
惠世恩
XU Weigang;TAN Houzhang;LIU Yuanyi;WEI Bo;HUI Shi’en(School of Mechanical Engineering,Changzhou University,Changzhou 213164,China;Key Laboratory of Thermo-Fluid Science and Engineering of MOE(Xi’an Jiaotong University),Xi’an 710049,China)
出处
《中国电力》
CSCD
北大核心
2018年第7期113-119,共7页
Electric Power
关键词
燃煤锅炉
水冷壁
高温腐蚀
硫化氢
腐蚀判据
腐蚀膜开裂
coal fired boiler
water walls
high temperature corrosion
H2S
corrosion judging standard
cracking of corrosion film
