Characterization of nanoparticles at the exhaust of a Common Rail Diesel engine by optical techniques and conventional method

Broadband ultraviolet-visible extinction and scattering spectroscopy (BUVESS) and Laser-Induced Incandescence (LII) were used at the undiluted exhaust of a Common-Rail diesel engine for detection, sizing and counting nanoparticles. BUVESS and LII are powerful in situ and non-intrusive techniques. BUVESS is based on multiwavelength extinction and scattering spectroscopy. It overcomes the intrinsic limitations of single wavelength techniques because it takes advantage of data at several wavelengths to retrieve primary particle size distribution with better accuracy. LII measures volume concentration and mean size of primary particles with a large measurement range, not limited by aggregate size. The optical results were compared with those obtained by conventional methods like opacimeter for mass concentration and Electrical Low Pressure Impactor (ELPI) for sizing. In this work, experimental investigations upstream and downstream Catalyzed Diesel Particulate Filter (CDPF) of 16 v - 1.9 l Common-Rail diesel engine were performed at different engine speeds and loads.