针对超临界机组低压末级带冠叶片在运行过程中轴向振动位移与径向叶顶间隙变化难以精确同步测量的技术难题,本文提出一种基于双电涡流差分测量方案。通过在叶片顶部机匣布置两支轴向位置不同的传感器同步采集动态电涡流信号,对信号间所包含的差模与共模特征进行分离,有效解耦叶片的轴向振动位移量与径向叶顶间隙变化量。该方法能实现对带冠叶片轴向振动与径向间隙的同时监测,克服传统单电涡流测试的局限性,为汽轮机末级带冠叶片运行状态评估与健康监测提供了更加可靠、精准的技术手段。

Addressing the challenge of simultaneous precision measurement of axial vibration displacement and radial tip clearance in supercritical unit LP-stage shrouded blades, this paper proposes a dual-eddy-current differential measurement scheme. Two axially displaced sensors mounted on the casing simultaneously acquire dynamic signals. The differential and common-mode components are then separated to decouple the axial vibration from radial clearance changes. This method enables concurrent monitoring, overcoming the limitations of single-sensor eddy current testing and providing a more reliable and accurate means for condition assessment and health monitoring of these blades.