拉曼积分球原位检测燃油发动机尾气成分  

In Situ Detection of Fuel Engine Exhaust Components by Raman Integrating Sphere

作　　者：黄保坤 赵倩男 刘叶繁 朱琳 张鸿 张韫宏 刘艳[4] HUANG Bao-kun;ZHAO Qian-nan;LIU Ye-fan;ZHU Lin;ZHANG Hong;ZHANG Yun-hong;LIU Yan(School of Science,Jiangsu Ocean University,Lianyungang 222005,China;School of Electronic Engineering,Jiangsu Ocean University,Lianyungang 222005,China;Department of Chemistry,School of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing 102488,China;Laboratory of Advanced Energy and Power,Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]江苏海洋大学理学院,江苏连云港222005 [2]江苏海洋大学电子工程学院,江苏连云港222005 [3]北京理工大学化学与化工学院化学系,北京102488 [4]中国科学院工程热物理研究所能源动力研究中心,北京100190

出　　处：《光谱学与光谱分析》2023年第10期3310-3313,共4页Spectroscopy and Spectral Analysis

基　　金：国家重大科研仪器研制项目(42127806)资助。

摘　　要：燃油发动机的尾气成分检测对于发动机的状态判断、环境污染监测等具有重要参考价值。选择以95号汽油为燃料的除草机的发动机作为实验样机,将发动机排出的尾气直接吹向拉曼积分球光谱仪信号采集焦点,利用拉曼积分球光谱仪较高的气体检测限和定性、定量检测所有分子类气体的特点,对尾气中的气体分子成分进行检测。探测到尾气的气体成分主要包括N_(2)、O_(2)、CO_(2)、CO、未燃烧的汽油等。以氮气振动(2331 cm^(-1))的拉曼特征峰强度作为标准,对O_(2)(1553 cm^(-1))、CO_(2)(1285和1388 cm^(-1))、CO(2144 cm^(-1))、未燃烧的汽油(2894 cm^(-1))的拉曼光谱强度进行归一化处理,获得其相对拉曼特征峰强度。对比发现,空气和汽油挥发混合气的光谱中均未出现CO的特征峰,汽油挥发混合气中的O_(2)、CO_(2)含量与空气相比也没有明显变化,而CO_(2)费米共振峰1388和1285 cm^(-1)拉曼特征峰的相对强度比发生变化。除草机工作状态分为怠速、一档和二档,处于工作状态时,尾气成分中的O_(2)含量均比空气中含量低,可以定量分析发动机工作过程中消耗的O_(2)量。而燃油发动机从怠速加速到一档和二档的过程中,尾气中O_(2)含量相对增加。这是由于发动机档位的提升伴随着空气的进气量增大,则参与发动机燃烧的氧气比例相对减少。与此同时,尾气中CO_(2)含量相比于空气中的含量急剧增加,说明燃油发动机工作过程会产生大量的CO_(2),且随着档位的提升,发动机的动力增加,尾气中CO_(2)比例也逐渐增高。CO_(2)作为导致温室效应的主要原因,化石燃料的使用也是其主要来源之一。数据显示尾气中CO的含量与尾气中汽油的含量成正相关,说明燃烧不充分的时候,汽油剩余较多,CO作为不充分燃烧的产物,其含量也会增加。随着发动机档位的增加,N_(2)特征峰的绝对强度降低,这是因为发动机尾气温度升The detection of the exhaust gas components of a fuel engine has important reference values for engine condition determination and environmental pollution monitoring.For this study,a weedkiller engine powered by No.95 gasoline was chosen as the experimental prototype,and the exhaust gas from the engine was blown directly into the signal acquisition focus of the Raman integrating sphere spectrometer.The high gas detection limit and the ability of the Raman integrating sphere spectrometer to probe all molecular gas qualitatively and quantitatively have been used to probe the molecular component of the gas in the tails.The gas component detected in the trailing gas is dominated by N_(2),O_(2),CO_(2),CO,and unburned gas.The relative Raman characteristic peak intensities of O_(2)(1553 cm^(-1)),CO_(2)(1285 cm^(-1)and 1388 cm^(-1)),CO(2144 cm^(-1)),and unburned gasoline(2894 cm^(-1))were obtained by normalizing the Raman spectral intensities using the Raman characteristic peak intensity of nitrogen vibrations as a standard.It can be found that the characteristic peak of CO does not appear in the spectrum of volatile matter of air and gasoline,and the content of O_(2)and CO_(2)in volatile matter of gasoline does not change significantly compared with that of air,while the relative intensity ratio of Raman characteristic peak of CO_(2)Fermi formant 1388 and 1285 cm^(-1)change.The working state of a lawnmower is divided into idler,first and second gear.When operating,the O_(2)content in the exhaust components is all below that in the air,allowing quantitative analysis of the amount of O_(2)consumed during engine operation.The O_(2)content in the exhaust increases relatively when the fuel engine is increased from idle to first and second gear.It is because as the engine gear increases,so does the air intake,and the proportion of oxygen involved in engine combustion is relatively reduced.At the same time,the amount of CO_(2)in the tailpipe gas increases dramatically compared to the amount in the air,suggesting that the worki

关 键 词：发动机尾气 拉曼积分球 光谱仪 原位检测 

分 类 号：X851[环境科学与工程—环境工程]