红外线热成像在压水堆核电站二回路阀门壁厚检查中的应用

Application of Infrared Thermography in Valve Wall Thickness Inspection of Secondary Circuit in PWR Nuclear Power Plant

压水堆核电站的二回路系统功可以将饱和蒸汽的热能转换为机械能,并构成一个完整的热力循环,这样不仅能够保证汽轮机的安全,还能有效提高核电站的整体热效率。但是,在长时间的运行过程中,二回路系统中阀门阀体的敏感部位会受到不同程度的冲蚀,导致局部阀体减薄现象的发生。本文提出了一种红外线热成像技术在核电站二回路阀体壁厚检查上的工艺方法,并通过实验室和现场试验验证了该方法的有效性。结果表明,红外线热成像技术可以作为阀体壁厚检查的一种有效手段,适当的检测工艺可以有效的筛选出阀体可能减薄的区域,可以结合其他检测方法,综合判断减薄趋势。

The secondary circuit of PWR nuclear power plant can convert the heat energy of saturated steam into mechanical energy,and form a complete thermal cycle,which can not only ensure the safety of steam turbine,but also effectively improve the overall thermal efficiency of nuclear power plant.However,in long-term operation,the sensitive parts of valve body in the secondary circuit would be eroded to varying degrees,resulting in local valve body thinning.In this paper,an infrared thermography was proposed for the wall thickness inspection of valve body in the secondary circuit,and its effectiveness is verified by laboratory and field tests.The results show that infrared thermography can be used as an effective method for the wall thickness inspection of valve body,and appropriate detection technology can effectively screen out the possible thinning area of valve body.Combined with other detection methods,the trend of thinning can be estimated comprehensively.