基于非分散红外-转化炉法的氮氧化物组分含量测定装置测量不确定度分析

Uncertainty Analysis of Nitrogen Oxide Component Analyzer Using Non-Dispersive Infrared-Conversion Furnace Method

对非分散红外-转化炉法的氮氧化物组分含量测定装置的不确定度的主要来源进行了分析和评估,提出基于转化法的氮氧化物组分测定装置测量烟气中总氮氧化物不确定度的评定方法,并按照JJF1059.1-2012《测量不确定度评估与表示》的提供的方法,结合具体示例进行了不确定度分量和合成标准不确定度的评定和计算,并最终报告了装置测量的扩展不确定度。研究结果表明,采用该非分散红外-转化炉法的氮氧化物组分含量测定装置测量烟气中氮氧化物总量,其测量结果的相对扩展不确定度为Urel=1.4%(k=2)。该研究所确定的不确定度评定方法,充分考虑了氮氧化物转化炉转化效率和烟气中氮氧化物组分构成特点对氮氧化物总量测量的不确定度影响,从而提高了氮氧化物测定装置对烟气中氮氧化物组分总量测定的科学性和有效性。

The main sources of uncertainty of the nitrogen oxide component content measurement device of the non-dispersive infrared with conversion furnace method were analyzed and evaluated.And then the uncertainty evaluation method of measurement by nitrogen oxide component detection device based on conversion method is presented,which utilized to measure the total nitrogen oxides in the flue gas.In accordance with the method provided in JJF 1059.1-2012"Evaluation and Expression of Uncertainty in Measurement",the evaluation and calculation of the uncertainty component,the combined standard uncertainty was carried out with a specific example.Finally,the expanded uncertainty of the device was also reported.The results showed that the relative expanded uncertainty of the measurement result is reported as Urel=1.4%(k=2).The uncertainty evaluation method determined in this study has taken into account the influence of the conversion efficiency of the nitrogen oxide conversion furnaces on the uncertainty of the total nitrogen oxide measurement,as well as the composition characteristics of nitrogen oxides in the flue gas.This work would improve the scientificity and validity of the measurement for the total amount of nitrogen oxide components in the flue gas.