Small Cars Emissions Exceed The Standard Scheme Of Reason Analysis And Improvement In Nanning City

In recent years,with the development of automobile industry,car ownership in China has more than 184 million vehicles,while the small displacement passenger car retains the quantity amounts to 147 million.Nanning city which is the capital city of the Guangxi Zhuang Autonomous Region Province and Chinese connecting ASEAN bridgehead,is an important hub of Southwest Chinese exit road and an important component of "city Belt and Road Initiative".The overall air condition of Nanning is in the range of law,but the emission of pollutants such as HC,NOx and so on can not be ignored.It is a threat to human health and the environment.This paper is from Nanning city in 2014 for major projects of city environment comprehensive prevention and control of appropriate technology research and application demonstration of the "Nanning vehicle emissions exceed the standard control techniques research and application demonstration".This paper takes Nanning city small cars as the research object,which such as emission characteristics,pollutant composition,formation mechanism of the small displacement passenger cars in the Nanning area,the problems such as the cause of excessive discharge and maintenance and improvement measures are studied.Specific work and research are as follows:1.To analyze the current situation and development trend of the research on small displacement passenger cars at home and abroad,and to focus on the corresponding treatment plan to the problem of excessive discharge.2.In Nanning,the subtropical monsoon climate characteristics and city traffic characteristics such as geographical factors,formation mechanism of CO,HC,NOx the three kinds of harmful gases.3.By three kinds pollutant formation mechanism and garage practice to collect data on the cause of Nanning City,small cars emissions exceed the standard,and will use FAHP to the influence of common faults on emissions calculation.The influence degree of order:Three element catalytic converter failure>Too much engine coke>Abnormal EGR system>Inlet system anomaly>Oxygen sensor failure.4.Based on the improved scheme of centralized and decentralized maintenance,the ASM steady state loading method is adopted in the test.In maintenance time,the vehicle equipped with OBD first according to the fault code troubleshooting,equipped without the OBD of the main consideration of the impact of failure on the emission and the age of the common failure of the impact,and the use of appropriate measures to improve emissions.