压缩点火天然气发动机工作性能试验

围绕影响单一燃料天然气发动机压缩着火启动、运转和排放特性的相关因素进行了试验研究。设计开发了新型燃烧系统,通过台架试验研究了不同的辅助加热温度、隔热措施、进气温度及EGR对着火燃烧及排放的影响。试验结果表明电热塞温度、进气温度及主副燃烧室之间的通道直径对发动机的着火和起动性有显著的影响;可以实现仅利用电热塞辅助加热即可在常温进气条件下起动发动机。合适的EGR率可以降低HC和NOx排放量,同时可以稳定天然气发动机的燃烧过程。

Experimental Investigation on Operation Characteristics of the Compression Ignition CNG Engine

This paper introduced a new combustion system of the compression-ignition CNG engine, which was developed by the authors. The low heat rejection separate combustion chamber and compound gas injection system were employed in the new combustion system. The assistant heating temperature, the ceramic coating of combustion chamber, the intake air heating temperature and the effect of EGR on combustion and emission were studied. The results showed that heating temperature of the ceramic glow plug, the intake air and divided chamber geometry all had obvious influence on combustion and emission. The CNG engine could be started at the ordinary temperature just with the ceramic glow plug. The appropriate ratio of EGR could reduce HC and NOx exhaust, and could keep the combustion process of the CNG engine stabilization.