NDIR方法应用于汽油车NO排气检测的试验研究

为改善在用点燃式轻型汽车简易工况NO排气检测准确性,将NDIR检测法应用于NO的排放检测。采用比对测试方法,在184辆在用轻型汽油车的ASM排放检测中,同时采用NDIR方法与通用的电化学法进行排气NO浓度测试。测试结果表明,对于NO检测,NDIR方法与工况的跟随性较电化学方法好,电化学方法测试响应时间较NDIR方法滞后7~8s。采用有限差分法对两种检测方法的检测灵敏度进行分析,得出NDIR法的灵敏度为11.87,电化学法为6.97。分析NDIR法、电化学法两种检测方法下NO测试浓度值的相关性,发现两者高度线性相关,相关系数为0.98。研究结果表明NDIR方法完全适用于ASM工况NO排气浓度检测,其检测准确率较电化学方法高。

Application of NDIR on NO Measurement for Gasoline Car

The NDIR measurement method was applied to improve the NO measurement accuracy of light‐duty gasoline car under simple operating mode .NO emissions of 184 light‐duty gasoline cars were measured with NDIR and electrochemical method respectively according to ASM standard .The results show that the NDIR method has better following behavior for op‐erating conditions ,that is 7~8 s faster than the electrochemical method .The measurement sensitivity analysis of finite differ‐ence method shows that the sensitivity of electrochemical method and NDIR method is 6 .9 and 11 .87 respectively .It is further found that the correlation coefficient between measured NO emissions with NDIR and electrochemical method is as high as 0 .98 ,which proves that the NDIR method is appropriate for NO measurement of ASM conditions and can improve the meas‐urement accuracy .