摘要
针对火电机组深度调峰变工况过程中蒸汽温度大幅变化,引起机组部分结构热应力大幅增加,结构加速损坏,安全事故频发的问题,以300 MW汽轮机调节级转子为对象,利用Ansys软件对叶片热应力、气动力和离心力进行分析。首先对叶根部位开展结构优化,大幅消除常规计算普遍存在的不合理局部应力集中现象;然后研究揭示了火电机组深度调峰过程稳态和瞬态等不同情况下调节级温度场、应力场的分布规律及其对机组安全性能的影响特性。研究结果表明:稳态工况不同喷嘴组温差50℃时,最大等效应力升高约24%;瞬态工况升负荷速率5%THA/min比2%THA/min引起转子低周疲劳损伤提升约3倍;相较于稳态工况,每天增加一次速率2%THA/min从半负荷到满负荷的升负荷过程,综合损伤提升38%左右。
Under deep peak shaving and variable operating conditions of thermal power units,significant changes in steam temperature have caused a significant increase in thermal stress in some structures of the units,which accelerated structural damage,and resulted in frequent safety accidents.To solve these problems,by taking the regulating stage rotor of a 300 MW steam turbine as the object,and Ansys software is used to analyze the thermal stress,aerodynamic force,and centrifugal force of the blades.Firstly,structural optimization is carried out on root of the blade to significantly eliminate the unreasonable local stress concentration phenomenon commonly found in conventional calculations.Then,the distribution laws of temperature and stress fields in the regulating stage under different conditions such as steady-state and transient during the deep peak shaving process of thermal power units are revealed.Moreover,the effects of the temperature and stress fields on safety performance of the unit are also investigated.The results indicate that,the maximum equivalent stress increases by about 24%under steady-state conditions with temperature difference of different nozzle groups of 50℃.The transient load increase rate of 5%THA/min is about three times higher than that of 2%THA/min,causing low cycle fatigue damage to the rotor.Compared with steady-state operating conditions,increasing the load once a day at a rate of 2%THA/min from half load to full load increases the overall damage by about 38%.
作者
陈思远
黄畅
王卫良
吕俊复
柯希玮
刘志东
马庆中
CHEN Siyuan;HUANG Chang;WANG Weiliang;LYU Junfu;KE Xiwei;LIU Zhidong;MA Qingzhong(MOE Key Lab of Disaster and Control in Engineering,International Energy School(Energy and Electricity Research Center),Jinan University,Zhuhai 519070,China;Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China;Shanxi Research Institute of Huairou Laboratory,Taiyuan 030006,China;Guangdong Zhuhai Jinwan Power Generation Co.,Ltd.,Zhuhai 519050,China;Shanxi Guojin Coal Power Co.,Ltd.,Jiaocheng 030500,China)
出处
《热力发电》
CAS
CSCD
北大核心
2024年第10期106-113,共8页
Thermal Power Generation
基金
珠海市产学研合作项目(2220004003010)
中央高校基本科研业务费专项资金资助(21622420)。
关键词
深度调峰
调节级
汽轮机转子
热应力
蠕变疲劳
deep peak shaving
regulating stage
steam turbine rotor
thermal stress
creep and fatigue
