基于CLD机动车尾气NO_x排放快速在线检测研究

Research on Rapid On-line Detection of NO_x Emission from Motor Vehicle Exhaust Based on CLD

NOx是机动车污染物排放的主要检测指标,是环境监测最重要的参数之一。该文根据NO与O3的化学发光反应机理实现机动车尾气NO分析,应用光电二极管的光电转换技术,代替传统的光子计数器,设计了低成本高集成度的机动车尾气NO排放快速在线检测系统,并对气体的流速、压强、反应温度等影响参数进行理论分析和实验验证。结果表明,低浓度的NO气体,其浓度与发光强度线性相关,发光强度随着气体的流速、压强、反应温度的增加,均会产生明显的增大,在系统0~3067.48 mg/m3的量程范围内,系统检测线性度为0.9992,检出限为1.23 mg/m3,标准偏差2.12%,系统结构简单,响应时间短,满足国家新出台的检测标准要求。

NOxas the main parameter of vehicle emission,it is one of the most important parameters of environmental monitoring.According to the chemiluminescence reaction mechanism of NO and O3,the NO analysis of vehicle exhaust is realized.The photoelectric conversion technology of photodiode is used instead of the traditional photon counter.A low-cost and highly integrated on-line detection system for vehicle emission NO emission is designed.Theoretical analysis and experimental verification of the influence parameters of gas flow rate,pressure and reaction temperature are carried out.The experimental results show that the concentration of low concentration NO gas is linearly related to the luminous intensity,and the luminous intensity increases obviously with the increase of gas flow rate,pressure and reaction temperature.The linearity of the system is 0.9992 in the range of 0~3067.48 mg/m3 of the system.The detection limit is 1.23 mg/m3,the standard deviation is 2.12%,the system structure is simple,and the response time is short,so as to meet the new national standards.