| 英文摘要 |
The plan focuses on the research, estimation and establishment of the pollution control strategy for over 6 millions of automobiles in use in our country; in this year, the three major objects of the plan are as follows: 1. the estimation of the feasibility of adding the on-board diagnostic (OBD) system to the current periodical automobile inspection process and the establishment of the relevant projects thereof; 2. the selective emission pollution test operation for automobiles conforming to the environmentally-friendly 4th emission standard; 3. The collection operation of the current automobile particulate matter control statuses in US and Europe for automobiles with gasoline direction injection (GDI) engine.
In this year, the plan has acquired 5,375 pieces of OBD test data in total; the statistics result shows self-use van, business sedan or other kinds of automobiles with high VMT will have higher breakdown rate. Among the automobiles with diagnostic trouble codes, the most codes are the international universal codes related to the dynamical system. Among the abnormal items of the readiness status (RS), the most items are the catalyst sensor and the oxygen sensor. According to the selective test results for the last two years, the breakdown rate of the automobiles belonging to self-use sedan manufacturing in 2008 slightly increases; it is suggested to keep observing the change of the relation between the automobile age and breakdown rate. According to the research of the plan, it is suggested to add the inspection item of visually inspecting the malfunction indicator lamp (MIL) to the current periodical inspection process or make the coasting emission standard stricter.
The plan collects the selective test results of the automobiles meeting the 4th emission standard in recent years, which show 23 automobiles with OBD malfunction code obtain eligible emission test value from the periodical inspection; however, the emission test values of 17 of these automobiles exceed the emission standard for new automobile, and the over standard rate is about 74%, which show the OBD test items have higher pollution discrimination than the current emission inspection standard. Among these samples, the pollution over standard rate of the automobiles with abnormal catalyst is highest, which is up to 100%. Among the three controlled pollutants, the NOx has highest over standard rate, which is up to 69%; it is obvious that the OBD can effectively detect the abnormal situations of catalyst and NOx.
According to the literature collection results of the automobiles with GDI engine and PM control, US and Europe, currently, have yet to implement the PM emission measurement and control in the periodical automobile inspection. However, it is feasible to monitor the gasoline particulate filter (GPF) of automobiles in order to reduce the PM emission; it is possible to simultaneously solve the PM emission problem of the automobiles with GDI engine by controlling the OBD function statuses of the automobiles in use.
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