相同氧含量醇类混合燃料燃烧和排放特性差异研究

An experimental study was conducted on a 4-cylinder, direct injection diesel engine at a constant engine speed under five loads to evaluate the effect of different ternary fuels on combustion and regulated emissions of the engine. Several alcohols, namely, methanol, ethanol, butanol and pentanol, were mixed separately with a blended fuel containing diesel and biodiesel to prepare four ternary fuels with same oxygen concentration, including methanol blend(DBM), ethanol blend(DBE), butanol blend(DBBu) and pentanol blend(DBP). Results show that use of methanol blend allows to have the highest combustion pressure in alcohol blends, while butanol blend has the highest heat release rate. Moreover, pentanol blend has the best CO and HC emissions in comparison with diesel fuel, while the optimal NO_x emissions result from the use of methanol blend. Ethanol blend has the most obvious effect on particle reduction, which can reduce particle concentration by 22.4% to 55.6% and particle size by 3.4% to 12.8% and minimizing the emissions of nucleation mode and accumulation mode particles, while pentanol blend maximizes the emissions of both particles(except for high loads).