Emission Characteristics and Microscopic Morphology of Particles from a Gasoline Direct Injection Vehicle based on China Ⅵ Emission Regulation

Abstract:

The mass, cumulative quantity and micro-morphology of particulate matters from a China Ⅵ gasoline direct injection(GDI) vehicle during Worldwide Harmonized Light Vehicles Test Cycles (WLTC) have been researched experimentally. The results showed emission factors of particulate mass (PM) and particulate number (PN) were both lower than the regulation limits; The cumulative amount of particulate matters varied in three stages, which was significantly higher in the first 300s, the last 300s and 600～800s. The PN was much more when engine was started under cold condition; the accumulation from first 300s had been over the total amount of hot-engine operation. Particulate matters were mainly formed by basic carbon particles whose shapes were irregular. The basic carbon particles were composed of many microcrystalline carbon layers, the inner core was disordered while the outer shell was ordered; When basic carbon particles overlapped, some formed large particles and others formed large carbon particles. The characteristic parameters of basic carbon particles were all unmoral distribution, similar to the GDI engine; The distribution of basic carbon particles diameter, carbon crystal length and carbon crystal curvature were relatively concentrated and the values were all lower than test results of the engine bench.