Effect of Polyoxymethylene Dimethyl Ethers/Diesel Blends on Fuel Properties and Particulate Matter Oxidation Activity of A Light-Duty Diesel Engine

摘要

Polyoxymethylene dimethyl ethers (PODE) was blended in diesel at volume ratios of 0 %, 10 %, 20 %, and 30 % (denoted as P0, P10, P20, and P30). The experimental study was carried on an unmodified YD480Q diesel engine. An engine exhaust particle sizer was introduced to analyze the particulate matter (PM) concentration and particle size distribution of diesel engine emission. The evaporation-oxidation characteristics of the PODE/diesel blends and the effect of the fuel blends on the oxidative activity of PM were investigated by thermogravimetric analysis and Arrhenius theorem. The results showed that blending PODE in diesel improved the evaporation-oxidation characteristics of the fuel and decreased the apparent activation energy of the fuel blends. PODE played a positive role in reducing PM emissions. The particle total number concentration of P30 decreased 28.29 similar to 66.60 % and the particle total volume density decreased 54.16 similar to 80.06 % compared to diesel. The particle size distribution shifted to a smaller particle size as the PODE blending ratio was increased. The mass fraction of the volatile substances (VS) increased and the mass fraction of the dry soot (DS) decreased by employing PODE as a diesel additive. Also, the oxidation activity of VS increased as the PODE blending ratio was increased. The oxidation activity of DS climbed to the peak when the PODE blending ratio was 20 % and then decreased.