Effect of Crankcase Blow-by on Particle Emission of Internal Combustion Engine

摘要

By controlling the flow of crankcase blow-by to atmosphere or intake system, number concentration of particle distribution was measured in a diesel engine and a gasoline direct injection engine (GDI engine). The effect of blow-by on particle emission was investigated in different conditions. EEPS (3090) exhaust particle spectrometer and exhaust dilution and measurement & control system were used in those tests. The results show that leading blow-by of crankcase into the intake system increases the particle number concentration peak value and develops new concentration peak area. For the diesel engine, blow-by mainly affects the concentration distribution of nuclei model particle and the accumulation mode particle less than 100nm; for the gasoline GDI engine, blow-by of crankcase mainly affects the concentration distribution of nuclei model particle. In addition, taking blow-by of crankcase into intake system leads to the increase in the total number concentration of particle in all conditions. For the diesel engine, the increase of total number concentration in the condition of middle and high amount of blow-by are 44.2%and 38.5%; for the gasoline GDI engine, the increase of total number concentration in the condition of low blow-by leakage reaches up to 93.8%.