摘要
针对汽轮机高温紧固螺栓的蠕变、疲劳及蠕变-疲劳交互作用三种失效模式,以某典型中压联合汽阀螺栓为例对影响螺栓蠕变寿命、疲劳寿命以及蠕变与疲劳交互作用时的寿命的因素进行了计算、分析。分析表明:中压联合汽阀螺栓的预紧应力对螺栓的蠕变损伤量有较大的影响,预紧应力增加则所产生的蠕变损伤量增加;调峰运行方式下,疲劳寿命随着螺栓热应力的增加而降低增加。螺栓的螺纹固定端第1圈螺纹应力集中对蠕变寿命和疲劳寿命有较大影响。中压联合汽阀螺栓剩余寿命可安全运行6个检修周期,不能满足机组设计寿命的要求,需要采取降低参数运行、缩短检验周期或者在6个检修周期后更换中压联合汽阀螺栓的措施。
In view of the three failure modes of creep, fatigue and creep-fatigue interaction of high-temperature fastening bolts of steam turbines, the factors affecting the creep life, fatigue life and life of bolts when creep and fatigue interact were calculated and analyzed using a typical medium-pressure combined steam valve bolt as an example. The analysis shows that: the preload stress has a greater impact on the amount of creep damage to the bolt, a 10% increase in preload stress increases the creep damage by more than 23.0%;the two-shift operation mode is the main factor affecting the fatigue life of high temperature bolts, and the threaded fixed end of the bolt has a greater impact on the fatigue life of the first turn of thread stress concentration. The assessment of the life of the medium pressure combined valve bolts: in consideration of the stress concentration, the remaining life of the medium pressure combined valve bolts can be safely operated for 6 service cycles, which cannot meet the requirements of the design life of the unit, it is necessary to take measures to reduce the parameters of operation, shorten the inspection cycle or replace the medium pressure combined valve bolts after 6 service cycles.
作者
张艳飞
谢宝奎
管伟康
ZHANG Yanfei;XIE Baokui;GUAN Weikang(Inner Mongolia Electric Power Research Institute,Hohhot Inner Mongolia 010020,China;North Institute of Materials Science and Engineering,Baotou Inner Mongolia 014034,China;Inner Mongolia Energy Research Technology Center Co.,Ltd.,Baotou Inner Mongolia 014030,China)
出处
《宁夏电力》
2022年第2期55-60,70,共7页
Ningxia Electric Power
基金
内蒙古电力科学研究院科技项目(51241180013)。
关键词
高温螺栓
蠕变寿命
疲劳寿命
寿命评估
high temperature bolt
creep life
fatigue life
life evaluation
