Effect of intake oxygen enrichment on particle size distribution from a DI diesel engine

Abstract

The characteristics of particle size distribution in the exhaust gas of a four-cylinder turbo-charged diesel engine were studied. The oxygen concentration of the intake air was controlled by flow valve and oxygen sensor. Particle size distributions were measured with a fast particle analyzer (DMS500). Particulate matter number concentration, size distribution characteristics, geometric mean diameter (GMD), surface area distribution and volume, distribution were studied with the intake oxygen concetration at 21%, 22%, 23% and 24% under steady-state engine operating conditions. The results indicated that, under the same operation condition, the peak values of accumulative particulate matter number and mass concentration decrease with the increase of the intake oxygen volume; also particulate geometry mean diameter, surface area density and particle volume density decrease while the nuclei mode particle number concentration and small-diameter particles show a slight increase.