南宁市小排量乘用车排放超标原因分析及改进方案研究

发布时间：2018-08-03 20:55

【摘要】：近年来,随着汽车工业的发展,我国汽车保有量以已超过1.84亿辆,而小排量乘用汽车保有量达1.47亿辆。南宁市作为广西壮族自治区省会城市,是中国连接东盟各国的桥头堡,是中国西南出口道路的重要枢纽,是"一带一路"的重要组成城市。南宁市整体的空气状况随在法律规定的范围内,但是NOx、HC等污染物的排放量也不容忽视,对人类的健康和大气环境造成了威胁。本文课题来源为南宁市2014年重大专项城市环境综合防治适宜技术研究及应用示范中的《南宁市机动车尾气排放超标治理技术路线研究及应用示范》。本文以南宁市小排量乘用车作为研究对象,对南宁市范围内小排量乘用车的排放特征、污染物组成、生成机理以及排放超标原因和维修改进措施等问题展开研究。具体工作和研究如下:1.分析南宁市小排量乘车的种类构成,并确定为重点研究对象。2.针对南宁市的亚热带季风性气候特点和城市路况特点等地理因素,研究CO、HC、NOx这三种有害气体的生成机理。3.研究了导致南宁市小排量乘用车排放超标的原因,并运用FAHP对最为常见的故障对排放的影响程度进行计算研究,得出影响程度排序为:三元催化器失效发动机积炭过多EGR系统异常进气系统异常氧传感器故障。4.采用集中型检测和分散型维修的改进方案,在检测时采用ASM稳态加载法。维修时,装有OBD的车辆先根据故障码排查故障,未装有OBD的主要考虑故障对排放的影响程度和车龄导致的常见故障的影响,并采用相应措施改善排放。
[Abstract]:In recent years, with the development of automobile industry, the number of cars in China has exceeded 184 million, while that of small displacement passenger vehicles has reached 147 million. As the capital city of Guangxi Zhuang Autonomous region, Nanning City is a bridgehead between China and ASEAN countries. Nanning is an important hub of export road in southwest China and an important constituent city of "Belt and Road". The whole air condition of Nanning is within the scope of the law, but the emission of pollutants such as no _ XO _ HC can not be ignored, which poses a threat to human health and atmospheric environment. This paper comes from the research and application demonstration of the appropriate technology for comprehensive urban environmental control in Nanning in 2014, and the application demonstration of the technical route of vehicle exhaust emission exceeding the standard in Nanning. In this paper, the small displacement passenger vehicle in Nanning City is taken as the research object. The characteristics of emission, the composition of pollutants, the formation mechanism, the cause of the emission exceeding the standard and the maintenance improvement measures of the small displacement passenger vehicle in Nanning are studied. Specific work and research are as follows: 1. This paper analyzes the species composition of small displacement cars in Nanning City, and determines that it is the key research object. 2. In view of the geographical factors such as the climate characteristics of subtropical monsoon and urban road conditions in Nanning, the formation mechanism of three harmful gases, COHCOHCN _ x, was studied. The causes of excessive emission of small displacement passenger cars in Nanning are studied, and the influence of the most common faults on emissions is calculated by using FAHP. The order of influence is as follows: the failure rate of ternary catalytic converters is too much carbon deposit in engine, the abnormal oxygen sensor fault of abnormal intake system in EGR system. 4. The improved scheme of centralized inspection and dispersive maintenance is adopted, and ASM steady loading method is used in testing. In maintenance, the vehicle with OBD is checked according to the fault code first, and the influence of the fault on the emission and the common fault caused by the age of the vehicle is considered in the absence of OBD, and the corresponding measures are adopted to improve the emission.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X734.2;U464.134.4

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