传热管表面裂纹应力强度因子影响研究

Research on the Effect of Stress Intensity Factor of Heat Transfer Tube Surface Crack

针对蒸汽发生器传热管表面裂纹存在的应力腐蚀开裂问题,对传热管表面裂纹的应力强度因子进行了研究。利用解析法验证了有限元计算的准确性,对传热管表面裂纹在不同长度、深度、角度以及壁面温差条件下的应力强度因子分布及变化趋势进行了分析总结。计算结果表明:传热管表面裂纹主要为张开型裂纹,当裂纹与轴向夹角为0°时裂纹对传热管影响最大,其应力强度因子沿裂纹最深点呈对称分布,随裂纹长度、深度呈非线性增长,与温差呈线性增长。计算结果为传热管寿命评估及可靠性分析提供了参考。

Aiming at the problem of stress corrosion cracking existing in the surface cracks of steam generator heat transfer tubes,the stress intensity factors of the surface cracks of heat transfer tubes are studied.The accuracy of finite element calculation is verified by analytical method.The distribution and variation trend of stress intensity factor of heat transfer tube surface crack un⁃der different length,depth,angle and temperature difference are analyzed and summarized.The calculation results show that the surface cracks of the heat transfer tube are mainly open cracks,and the stress intensity factors are symmetrically distributed along the deepest point of the crack.When the angle between the crack and the axial direction is 0°,the crack has the greatest impact on the heat transfer tube,which increases nonlinearly with the crack length and depth,and linearly with the temperature difference.The calculated results provide a reference for the life evaluation and reliability analysis of heat transfer tubes.