一种涡扇发动机测温R型热电偶高精度采集方案

A high precision acquisition scheme of R-type thermocouple for temperature measurement of turbofan engine

设计了一种涡扇发动机测温R型热电偶高精度采集方案。根据热电偶中间温度定理,结合数字电子控制器实际运行场景,选取温度可测量的控制器插头作为热电偶传感器的冷端,这种新型冷端补偿方法解决了数字电子控制器内外温度差带来的冷端测量误差。同时,通过分析热电偶分度表,分段选取不同插值表,采用线性拟合评估方法,保证了软件运算速率和计算精度。利用FLUKE多功能检验仪,对R型热电偶信号采集回路进行了验证。结果表明,其性能指标满足要求,对于工程应用是一个合理可行的方案。

A kind of R-type thermocouple temperature acquisition scheme for turbofan engine was designed.According to the intermediate temperature theorem of thermocouple and combining with the actual operation scenario of digital electronic controller,the controller plug whose temperature can be measured was selected as the cold end of the thermocouple sensor.As a new cold end compensation method,the cold end measurement error caused by the temperature difference between the inner part and the outer part of the digital electronic controller was solved.At the same time,the operation rate and the calculation accuracy of the software were guaranteed by analyzing the thermocouple graduation table,selecting different interpolation tables in different sections and using the linear fitting evaluation method.The R-type thermocouple signal acquisition circuit was verified by the FLUKE multifunctional calibrator.The results show that its performance indicators meet the requirements,thus it is a reasonable and feasible scheme for engineering application.