核电厂消防管道电磁周向导波技术研究

Research on Electromagnetic Circumferential Guided Wave of Fire Water Pipes in Nuclear Power Plant

针对核电厂中大量以法兰连接的薄壁消防管道内壁球形腐蚀坑快速、可靠的检测需求,根据频散曲线及常见缺陷尺寸选择S1周向导波,对φ219mm×6.5mm管道上加工的不同直径、不同深度的球形孔进行透射信号及反射信号的研究。结果表明S1导波对不同尺寸的球形孔具有较为广泛的缺陷响应,2次扫查即可完成对管道的100%检测,灵敏度最高可达0.55%CSA(截面损失率),具备较高的检测效率及可靠性。

In view of the rapid and reliable detection requirements of a large number of spherical corrosion pits on the inner wall of thin-walled flanged pipes in nuclear power plants,the inspection parameters of electromagnetic circumferential guided waves are determined according to the dispersion curves and common defect dimensions,and the transmission and reflection signals of spherical holes with different diameters and depths machined on the φ219 mm×6.5 mm pipes are studied.The results show that S1 guided waves have a wide range of defect responses to spherical holes of different sizes.It can complete 100% detection of the pipes at most two scans,with a maximum sensitivity of 0.55% CSA(section loss rate),which has a high detection efficiency and reliability.