Gaseous Emissions and Particle Microstructure Characteristics of PODE/Diesel Blend Fuel.

Polyoxymethylene dimethyl ethers (PODE) has good application prospects as an alternative to diesel fuel with a great potential to achieve clean combustion on diesel engines. In current study, the effects of PODE/diesel blends with PODE volume fraction at 10 %, 20 % and 30 % on performance and emission characteristics are investigated on a common-rail diesel engine under different engine loads. The particle size distribution and microstructure characteristics of the combustion particles are also analized. Results show that the PODE/diesel blends have shorter ignition delay, higher in-cylinder maximum burst pressure and advanced heat release. The brake thermal efficiency increases slightly with the increment of PODE blending ratio. There is a simultaneous improvement in CO, HC and soot emissions when fueling blend fuels. A more obvious shifting tendency toward the direction of small particle size can be found in number concentration, mass density and mass cumulative distribution of particles with increment of PODE. The microstructure of the blend fuels combustion particles is mainly in the form of agglomerates. Compared with diesel fuel, combustion particles of blend fuels have bigger layer spacing and microcrystalline curvature as well as smaller crystallite size, also the box dimension of the particles and the degree of agglomeration increase. [ABSTRACT FROM AUTHOR]