轻型汽油车国六排放标准可行性研究

Study on probability of compliance with China 6 standard for the emission from light duty gasoline vehicles

研究了国五排放水平的缸内直喷(GDI)汽油车和普通进气道喷射(PFI)汽油车按照国六排放标准规定的测试规程在常温(23℃)和低温(-7℃)冷启动下污染物的排放特性。结果表明:PFI汽油车的CO和HC排放量比GDI汽油车高4.3%~39.5%,NOx、颗粒物质量(PM)和颗粒物数量(PN)排放量低69.8%~82.7%。由于GDI汽油车PN的排放量较高,与PFI汽油车相比,达到国六排放标准的难度更大。2种汽油车低速时各种气态污染物的排放量远高于中速、高速和超高速,但PFI汽油车NOx排放量在超高速下比中速和高速有所增高,仅比低速下低约22.2%。

The emission characteristics of the gasoline direct injection （ GDI）vehicle and the common port fuelinjection （ PFI ）gasoline vehicle at China 5 emission level were studied under the test procedure of roomtemperature （ 23 ℃）and low temperature （- 7 ℃）coldstart according to China 6 standard. The results show thatthe CO and HC of PFI vehicles are about 4. 3%39. 5% higher than those of GDI vehicles,and the emission ofNOx ,particulate matter （ PM）and particulate number （ PN）is about 69. 8%82. 7% lower. Because of the highemission of PN,GDI vehicles are more difficult to reach China 6 standard than PFI ones. In term of speeds,theemission of various gaseous pollutants at low speed is much higher than that at medium speed,high speed and superhigh speed. However,NOx emissions at super high speeds have increased,only about 22. 2% lower than that oflow speed.