通过试验的方法,开展了多脉冲喷射模式下不同燃烧控制参数对重型柴油机低温燃烧过程影响的规律性研究,并通过这些参数的耦合作用优化出了多脉冲喷射模式下的最佳工况点.研究结果表明,在该喷射模式下获得了超低的NOx和碳烟(Soot)排放,同时维持了较高的指示热效率,且低温燃烧模式下积聚态微粒的平均粒径大小在40～65tm内,核态微粒的平均粒径大小在12～18 nm内.研究还发现,大EGR率时,NOx和Soot的排放率受共轨压力的影响较小,但积聚态的微粒数浓度随轨压的增大而减小.%Experimentally studied the effects of different combustion control parameters on Iow temperature combustion of a heavy duty diesel engine under the multi-pulse injection mode and obtained the best operation point by optimizing parameters in this injection mode. Results show that this mode can simultaneously achieve ultra-low NOx and Soot emissions, and at the same time keeps high values of IMEP and indicated thermal efficiency. The average particle size of accumulation mode is in the range of 40 to 65 nm, while the average particle size of nucleation mode is in the range of 12 to 18 nm. Results also show that NOx and Soot emissions are less affected by common-rail pressure under large EGR rate, but the particle number concentration of accumulation mode decreases with the increase of common-rail pressure.
展开▼
