【作者】 刘强；

【导师】 张乐福； 王宏；

【作者基本信息】 上海交通大学 ， 核能与核技术工程， 2007， 硕士

【摘要】 压水堆核电站所采用汽轮机为饱和蒸汽型汽轮机,其低压缸末级叶片很容易发生水蚀,如果叶片出现问题导致故障会给核反应堆运行造成运行瞬态事件,因此对核电站安全性、经济性都有着严重威胁。本文主要针对汽轮机末级叶片的水蚀问题展开研究,系统地分析了叶片水蚀的成因和机理,从叶片的设计理念、运行工况、选材、结构和刚性等方面总结了防止或减轻水蚀的防护措施。本课题以综合解决秦山二期650MW核电机组低压缸末级叶片出现的水蚀问题为目标,在理论和试验研究的基础上,联系运行实践,通过对各种修复及防护方法的对比,找到尽可能合理可行的水蚀叶片修复和减轻叶片水蚀的办法,致力于实际问题的解决,以实现公司效益的最大化。论文根据叶片水蚀机理、防护措施和秦山二期650MW汽轮机低压缸末级叶片具体情况的综合分析,确定水蚀叶片的修复方法采用钎焊法更换司太立合金片的方法解决,为了验证司太立合金片钎焊的可靠性,在哈尔滨汽轮机厂进行了现场试验。本文针对在秦山二期核电站现场实施的要求,制定了叶片水蚀程度评估标准、现场更换工艺规范、操作程序和质量评定标准等,并依据此对水蚀叶片进行了修复及更换司太立合金片的工作。经过运行一个周期后的实际效果比较,证明更换末级叶片司太立合金片的方法是可行的,有利于提高电厂经济性,同时也表明,本文提出的水蚀程度评判标准、修复工艺、操作规程和质量评判标准都是合理的,对于核电厂汽轮机末级水蚀叶片现场实施修复过程具有较好的指导作用。更多还原

【Abstract】 Water erosion occurs frequently at the last stage blades of saturated steam turbine in PWR power plant. The erosion in blades would induce unexpected transient during plant operation, threatening the safety and economy of plant. The author systematically analyzed the factors affecting erosion rate in the aspects of designing, operation, material, structure and rigidity. Methods for erosion protection were summarized based on the survey of literatures, aiming at maximizing the performance of the nuclear power plant.The objective of this thesis was to find the general means to solve the problem of erosion of last stage blades of QINSHAN Phase II Nuclear Power Plant. By comparison of various methods of erosion protection and repair of the eroded blades, braze welding was decided to be utilized to as the priority method to repair the eroded blades. The process for braze welding was verified in Harbin Turbine Co. Ltd., before on-site execution. Criteria and procedures for evaluation of the extent of erosion on the blade, as well as the process for on-site replacement of the stellite strip and methods for quality assurance of repair activity, have been set before performing the repair action. Accoring to the pre-determined procedures, eroded blade repair and stellite strip replacement action were performed during the previous refueling outage.After one operation cycle, the replaced Stellite strip on the Last Stage Blades were inspected during outage. It was confirmed that degree of water erosion on the replaced strip satisfiable to the technical requirement, proving that the proposed evaluation criteria, repairing process, procedures and quality assurance of the eroded blade are practicable, and can be adopted as the guidance for on-site assessment and repair of eroded turbine last stage blades.更多还原