压水堆蒸汽发生器传热管微动损伤监测关键技术研究

Monitoring the fretting wear of pressurized water reactor steam generator(SG) tubes plays a significant role in accurately obtaining the fretting wear state of SG tubes and predict its service life, optimizing the design of SG tubes and improving the safety co-efficiency of pressurized water reactor. The key of monitoring the fretting wear of tubes is to use the force sensor to measure the fretting wear between tubes and the tube pad, but the common-used force sensor can’t satisfy that demand due to its work temperature and volume issues. In terms of that problem, the project aims to design a high-temperature and high-pressure miniature fiber optic force sensor based on white light interferential optic fiber Fabry-Perot principle, study the micro-process and the integrative package technology of micro sensor optical path, investigate the temperature- and pressure- proof package technology of sensors and finally make out the right sensors. On the base, according to the feature of the newly-designed force sensor, this project aims to design a multi-channel high-speed fiber force sensor demodulation system, study out the solution of the mode obstruction issues of sensor optical path (multimode fiber), realize the functional limit of the existing fiber Fabry-Perot demodulation system and achieve the target of sampling frequency 10KHz and accuracy 0.1N, the high-precision and high-speed demodulation with multi-channel synchronous speed 5ns, and carry on confirmatory experiment on the steam generator model. The research findings will provide a new technical means for monitoring the fretting wear of pressurized water reactor steam generator tubes.

压水堆蒸汽发生器传热管微动损伤监测，可以准确获悉传热管微动状态，预测其使用寿命；有利于优化蒸汽发生器设计，进而提高压水堆安全系数，具有重要意义。传热管微动损伤监测的关键是利用力传感器测试传热管和管座间的微动磨损，常用的力传感器因工作温度和体积限制无法满足这一测试要求。针对这一问题，本项目拟基于白光干涉型光纤法珀传感原理设计高温、高压、微型光纤力传感器，研究微型传感光路的微加工和一体化装配技术；研究传感器的耐高温、高压封装技术；并最终加工出该传感器。在此基础上，本项目拟根据新设计的力传感器特征，设计多通道高速光纤力传感器解调系统；研究解决传感光路（多模光纤）中的模式干扰问题；突破现有光纤法珀解调系统性能限制，实现采样频率10KHz、精度0.1N、多通道同步精度5ns的高精度、高速解调；并在蒸汽发生器模型上开展验证实验。研究成果可为压水堆蒸汽发生器传热管监测提供一种新的技术手段。

压水堆蒸汽发生器传热管微动损伤监测，可以准确获悉传热管微动状态，预测其使用寿命；有利于优化蒸汽发生器设计，进而提高压水堆安全系数，具有重要意义。传热管微动损伤监测的关键是利用力传感器测试传热管和管座间的微动磨损，常用的力传感器因工作温度和体积限制无法满足这一测试要求。针对这一问题，本项目成功研发出基于白光干涉型光纤法珀传感原理的微型光纤力传感器及其解调系统。完成了微型法珀力传感器的光路的微加工和一体化装配技术、传感器的耐高温、高压封装技术，成功实现了该传感器的批量加工；解决了传感光路（多模光纤）中的模式干扰问题，突破现有光纤法珀解调系统性能限制，实现了高精度、高速解调的解调系统；该系统性能为：力传感器的测量范围为0-200N，固有频率为15kHz；光纤法珀解调仪实现了六通道同步采样，采样频率达到10kHz，测量量程为0-200N，力分辨率为0.1N。合作单位中国核动力研究设计院反应堆工程研究所利用该系统在“华龙一号”蒸汽发生器全尺寸全流量模拟回路上进行了流致振动实验，首次获取了传热管的微动径向撞击力信号，对于分析和研究传热管的失效具有重要的价值。该系统的成功研制和使用，证明了光纤法珀传感系统在核电应用领域具有较强的应用前景，能够解决传统传感系统不能够解决的关键检测问题，为核电站的安全运行提供技术支撑。