Effect of PODE on Emission Characteristics of a China VI Heavy-Duty Diesel Engine

With its high cetane number and oxygen content, polyoxymethylene dimethyl ether (PODE) can promote engine combustion and reduce particulate emissions, which has become a key research object of diesel surrogate fuel. This study further explores the effects of blending PODE on emission characteristics of a China VI diesel engine. Diesel/PODE blends with the PODE volume blending ratios of 10%, 20% and 30% have been experimentally investigated in a China VI heavy-duty diesel engine at 1900 rpm and four different loads. Furthermore, the effects of EGR rates (Exhaust Gas Recirculation) rates (0–20%) on combustion and emission characteristics have been also discussed at 1700 r/min engine speed and 50% engine load condition. An exhaust gas analyzer and a particle counter were used to collect NOx, CO and THC emissions and particulate number (PN) emissions. The results show that the CO and THC emissions can be significantly reduced with the increase in the mixing ratio of PODE. Additionally, the particle number concentration can be also reduced, especially at low and high loads. The NOx emissions can be improved by increasing EGR rates. Interestingly, there is a trade-off relationship between PN and NOx emissions. In general, blending PODE can effectively reduce NOx and PN emissions simultaneously.