核电站蒸汽发生器传热管电磁超声导波自动化检测系统设计

蒸汽发生器传热管作为高温气冷堆核电站一回路压力边界的关键部件，承担着热交换及辐射屏障的重要作用，其结构完整性严重影响核电安全运行。针对该类特殊结构传热管的在役检查难题，设计了专用的电磁超声导波自动化检测系统，研制了内置单点检测式的磁场增强型电磁超声导波探头，开发了采用模块化组件的五轴联动多自由度自动运载装置，提出了基于机器视觉的管孔动态定位方法，建立了蒸汽发生器全尺寸模拟体试验平台并开展了定位精度测试与缺陷检测试验。试验结果表明所设计的自动化检测系统可实现任意位置目标管孔的高精度定位及自动行走，可识别模拟体上异种钢焊缝处与距离检测端约60 m处的刻槽缺陷，有效检测范围覆盖传热管全长，有望为高温气冷堆核电站蒸汽发生器特殊结构传热管的质量健康评价提供技术支撑。

Design of electromagnetic ultrasonic guided wave automatic detection systemfor heat exchange tubes of steam generator in nuclear power plants

The heat exchange tubes of the steam generator, as a key component of the pressure boundary in the primary circuit of the high temperature gas-cooled reactor nuclear power plant, plays an important role in heat exchange and radiation barrier, and its structural integrity seriously affects the safe operation of nuclear power. In response to the in-service detection difficulties of this type of special structure heat exchange tubes, a dedicated electromagnetic ultrasonic guided wave automatic detection system has been designed, a magnetic field enhanced electromagnetic ultrasonic guided wave probe with built in single point detection has been developed, a five axis linkage multi degree of freedom automatic transport device with modular components has been developed, a dynamic positioning method for tube holes based on machine vision has been proposed, a full-scale simulation test platform for steam generator was established, and positioning accuracy test and defects detection test were carried out. The experimental results indicate that the designed automated detection system can achieve high-precision positioning and automatic walking of target tube holes at any position, and can identify the notch defects at the weld of dissimilar steel and about 60 m away from the detection end on the simulator. The effective detection range covers the entire length of the heat exchange tubes, which is expected to provide technical support for the quality and health evaluation of the special structure heat exchange tubes of the steam generator in high temperature gas-cooled reactor nuclear power plants.