基于热电偶反串的温升效率测量不确定度分析

Uncertainty analysis of compressor temperature rise efficiency measurement based on thermocouple inversed connection

针对轴流压气机气动性能试验中存在的低压比温升效率评估问题,构建了常规测温方法与反串测温方法测量的温升效率不确定度数学分析模型,并采用某单级压气机真实试验数据进行了两种测温方法不确定度的对比分析。结果表明:相比常规测温方法,反串测温方法不仅消除了热电偶冷端环境温度测量引入的不确定度,还大幅降低了进口温度测量引入的不确定度,使温升效率测量不确定度减小幅度在30%以上。

In view of the problem of evaluating the temperature rise efficiency under low pressure ratio in the aerodynamic performance experiments of axial flow compressor,the uncertainty mathematics analysis models of temperature rise efficiency measured by the conventional method and a method with inversed connection of thermocouple were established respectively,and the uncertainties of temperature rise efficiency measured by two methods were analyzed com-paratively with real experimental data of a single stage compressor.The results showed that,compared with conventional method,the uncertainty of temperature rise efficiency with inversed connection of thermocouple was greatly reduced by more than 30%,by eliminating the uncertainty introduced by the cold end temperature measurement of thermocouple and reducing the uncertainty introduced by the inlet temperature measurement.