摘要
为探究电站锅炉管表面氧化膜剥落问题,本文基于ANSYS流固耦合方法建立温度场与应力场分布计算模型,以T91合金为研究对象,分析不同工况下的温度和应力响应。首先,计算100%负荷稳态下的T91温度场与应力场分布;进而重点研究动态调峰过程,模拟60 s内温度线性下降90℃过程中瞬态温度场和应力场演化特性;最后对比分析汽温60 s内阶跃下降、曲线下降过程中动态响应。结果表明:稳态工况下,氧化膜径向应力最大,环向应力次之,轴向应力最小。动态调峰过程中,蒸汽温度骤降,显著加剧氧化膜应力波动。线性降温模式应力峰值出现在降温末期,且氧化膜峰值应力随时间变小。阶梯降温模式通过分段控温有效抑制应力波动幅度,曲线降温模式通过函数控制入口蒸汽降温速率,使其逐渐降低,产生的应力幅值小于线性降温过程,显著降低了氧化膜剥落的风险。
To investigate the peeling mechanism of surface oxide films on power station boiler tubes,this study establishes a computational model for temperature and stress field distribution using the ANSYS fluid-solid coupling method.Taking T91 as the research object,the temperature and stress responses under various operating conditions were analyzed.First,the steady-state temperature and stress field distributions in T91 under 100% load were calculated.Subsequently,the analysis focused on the dynamic peak shaving process,simulating the evolution characteristics of the transient temperature and stress fields during a linear 90℃ temperature drop within 60 seconds.Finally,the dynamic responses during stepwise and curvilinear steam temperature drops in 60 seconds were compared.The results indicate that under steady-state conditions,the radial stress in the oxide film is the largest,followed by circumferential stress,with axial stress being the smallest.During the dynamic peak shaving process,a rapid drop in steam temperature significantly exacerbates stress fluctuations in the oxide film.In linear cooling mode,the stress peak occurs at the end of the cooling process,and the peak stress decreases over time.Stepwise cooling effectively suppresses stress fluctuation amplitude through segmented temperature control,while curvilinear cooling gradually reduces the inlet steam cooling rate via functional control.Both alternative methods yield smaller stress amplitudes than linear cooling,significantly reducing the risk of oxide film peeling.
作者
魏道君
杨晓明
陈张杨
朱忠亮
曾洁
张天翼
WEI Daojun;YANG Xiaoming;CHEN Zhangyang;ZHU Zhongliang;ZENG Jie;ZHANG Tianyi(Shandong Branch of China Huadian Co.,Ltd.,Jinan 250013,China;Laicheng Power Plant,Huadian Power International Co.,Ltd.,Jinan 250013,China;School of Energy,Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China)
出处
《失效分析与预防》
2025年第6期485-496,共12页
Failure Analysis and Prevention
基金
中国科协青年人才托举工程项目(KH24010471)。
关键词
高温受热面管
蒸汽侧氧化膜
有限元分析
氧化膜应力
high-temperature heating surface tubes
steam-side oxide film
finite element analysis
oxide film stress
