利用原位集成热电偶技术精准测量涡轮叶片表面高温温度的方法探究及误差分析

Methods and error analysis of high temperature measurements on turbine blade surface using in-situ embedded sensors

为实现航空发动机涡轮叶片表面高温温度的精准测量,首先需要对涡轮叶片表面薄膜热电偶进行精确校准,而校准误差主要起源于被校准热电偶与标准热电偶之间存在的温度迟豫。为此,该文在测试样品表面成功原位集成薄膜热电偶和铂点热电偶,进行高温重复循环试验,以铂点热电偶为校准基准,对多次重复循环的实验数据进行整体拟合,形成热电压与温度的校准曲线。并且对每一个测量数据进行误差分析,对校准误差范围形成有效的预估。结果表明:采用上述方法可以减少标准热电偶和被校准热电偶之间的温度迟豫,使涡轮叶片表面集成的薄膜热电偶校准相对误差可以有效地控制在±3%之内。

In order to accurately measure the high temperature on the aero-engine turbine blade surface,the first thing is to accurately calibrate the thin film thermocouple on the sturbine blade surface.The calibration uncertainties mainly originate from the temperature delay between the calibrated thermocouple and the standard thermocouple.In this paper,thin film thermocouple and Pt point thermocouple are successfully integrated onto the blade surface to carry out high temperature repetitive and cycle test.With the in-situ Pt point thermocouple as the calibration standard,the experimental data of multiple repetitive cycles are fitted as a whole to form the calibration curve of thermal voltage and temperature.The errors of each measurement data are analyzed to form an effective prediction of the calibration error range.The results show that the temperature delay between the standard thermocouple and the calibrated thermocouple can be reduced by using the above method,and the relative error of the integrated thin film thermocouple on the turbine blade surface can be effectively controlled within±3%.