叶尖定时旋转叶片实时振动测量技术

Real-time vibration measurement based on tip-timing for rotating blades

设计了一套基于叶尖定时传感的旋转叶片振动测量系统。系统主要由光电传感系统、数据采集与预处理系统、叶片振动数据处理系统三部分组成。叶尖定时传感器采用单根光纤发射、多光纤接收的 Y 型结构,并用高性能专用集成芯片完成弱光信号的放大检测,使传感器信噪比大于500,信号带宽大于 50MHz。利用 CPLD 和 DSP 技术,实现了叶尖定时信号的高速实时采集与处理;建立了同步共振条件下叶片振动的数据处理模型,实现了叶片振动的实时监测。整套测量系统在现场某大型压气机上进行了原理性验证,在转速高达 9210rpm的情况下测得的同步共振最大幅值为 0.4231mm,接近于同等条件下国外的测量结果,从而验证了整套测量系统的可靠性。

A vibration measurement system based on tip-timing for rotating blades is designed. The system is composed of three subsystems: an optical sensor system, a data collecting and preprocessing system, and a real-time data processing system. The tip-timing sensor, with a Y type structure for transmitting with single fiber and receiving with fiber bundles can implement the detection of faint light signals by using a high performance integrated chip. This design makes the SNR bigger than 500 and the bandwidth bigger than 50 MHz. In addition, the high-speed real-time collection and processing of tip-timing signals are realized with CPLD and DSP devices; the blade synchronous vibration signals are monitored synchronously by means of modeling the data processing model. The principle of measurement has been validated on some big type turbine engines. The synchronous resonance amplitude measured is as 0.4231 mm at high speed up to 9210 rpm. Experimental data of field test proves that this method effective and reliable.