国六天然气发动机NOx排放测量的不确定度评定及分析  

Uncertainty Evaluation and Analysis of NOx Emissions Measurement from China VI Natural Gas Engine

作　　者：李娜 闫鹏勇 邱君 高涛[1] 汪晓伟 吴春玲 Li Na;Yan Pengyong;Qiu Jun;Gao Tao;Wang Xiaowei;Wu Chunling(CATARC Automotive Test Center(Tianjin)Co.,Ltd.,Tianjin 300300;China Automotive Technology and Research center Co.,Ltd.,Tianjin 300300)

机构地区：[1]中汽研汽车检验中心(天津)有限公司,天津300300 [2]中国汽车技术研究中心有限公司,天津300300

出　　处：《中国汽车》2024年第1期39-46,共8页China Auto

摘　　要：基于某满足国六排放标准的重型天然气发动机的NOx污染物比排放测量结果,结合参考文献和试验室实际检验情况,给出了重复性测量、测功机设备、排放分析设备、全流稀释系统、NOx湿度校正系数等方面引入的不确定度的评定过程。对评定结果分析发现个别影响因素引入的不确定度的计算过程不符合其工作原理,误差类型的处理比较模糊以及存在原始数据为检定和剔除离群值的情况。最终,本文从设备和标准气体参与影响的作用原理出发,对NOx污染物比排放测量结果进行了重新评定,给出了对评定结果影响最大的2个因素和评定过程注意事项,为试验室开展类似的不确定度评定提供了借鉴作用。Based on the specific emissions of NOx from a heavy-duty natural gas engine that meets the China VI standard,combined with references and actual laboratory testing,the evaluation process of uncertainty were given from the repeatability measurement,dynamometer equipment,exhaust analyzer,full-flow dilution system,NOx humidity correction factor.The analysis of evaluation results shows that the calculation process of uncertainty introduced by individual influencing factors does not conform to its working principle,the processing of error types is fuzzy,and the original data is not verified and the outlier is removed.Finally,based on the principle that equipment and standard substances participate in the influence,this paper re-evaluates the measurement results of specific NOx emission,and gives the two factors that have the greatest impact on the evaluation results and the precautions in the evaluation process,which provides a reference for the laboratory to carry out similar uncertainty assessment.

关 键 词：不确定度评定 天然气发动机 NOx比排放 国六排放 标准气体 离群值 

分 类 号：U46[机械工程—车辆工程]