降低压缩比改善HCII燃烧中高负荷特性的试验研究

Experimental investigation of improving HCII combustion at medium and high load by reducing compression ratio

均质混合气引燃(HCII)燃烧方法具有高效率低排放的特点,但是在中高负荷工况条件下,汽油比例受到粗暴燃烧的限制。本文采用降低压缩比方法以改善HCII中高负荷燃烧粗暴的问题,并在重型多缸柴油机上进行了试验验证。结果表明,将压缩比由18降为16能够有效控制发动机的最高燃烧压力,拓展汽油比例的范围,由此明显改善了HCII在中高负荷的燃烧和排放特性,尤其是碳烟排放的降幅在特定工况能够接近50%。本文研究结果对其他双燃料发动机也有一定参考价值。

Homogeneous charge induced ignition (HCII) combustion can achieve low emissions and high efficiency. However, the gasoline ratio of HCII combustion at medium and high load is limited by rough combustion. In this paper, a lower compression ratio was utilized to relieve the rough combustion at medium and high load. This strategy was verified by experiments on a heavy-duty multi-cylinder engine. The results showthat by reducing the compression ratio from 18 to 16 the peak in-cylinder pressure is effectively reduced and thegasoline ratio range can be obviously extended. Thus, the combustion and emission characteristics of HCII atmedium and high load are noticeably improved. The reduction of soot emissions at specific operating conditions can be close to 50%. These results also have reference value for other dual fuel engines.