蒸汽发生器炉管减薄规律初探

在4台蒸汽发生器辐射段炉管上分别选取多点进行管壁厚度测量，并根据测厚结果进行统计分析，找出在用蒸汽发生器的炉管管壁减薄规律：受热强度越大且位于蒸发段的炉管管壁减薄程度越明显。这是炉管长期处于高温环境下发生蠕变变形所致。如果再加上炉管的介质流动不畅或管壁结垢等因素，这个部位就容易发生炉管鼓包或爆管事故。爆管发生时破口特征为纵向破裂，表面有氧化皮。为保证蒸汽发生器安全、经济运行，要作好炉管蠕变变形测量；要对超期运行的炉管进行材质鉴定，作出金相分析；要保证炉管焊接质量，作好焊缝探伤，以及加强水质管理和炉管状态监测等。

Thinning pattern of steam generator tubes

Multipoint test of wall thickness of steam generator tubes on radiant section is carried out. Statistical analysis of the test data is made to find out the thinning pattern of the steam generator tubes. Tubes located on the evaporation section may get thinner more easily with high hot strength. The reasons lie in the bulges and puncture of the tubes resulted from the creep deformation at high temperature and bad circulation in the tubes and scaling. To ensure safe operahon of the steam generator, creep deformation of the tubes should be measured periodically with care, the quality of the tube material should be appraised, the welding quality of tubes should be ensured, and water quality management and tube condition monitoring should be strengthened.