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利用快速压缩装置进行了天然气直喷分层燃烧可行性的研究。结果表明 :天然气分层燃烧具有短的初期火焰发展期和主燃期以及高的燃烧压力。分层燃烧可使稀燃极限延伸到很小的当量比。由于过度分层 ,CO在当量比大于 0 .8时急剧增加 ,而 NOx 的峰值也因充量分层而出现在小当量比处。燃烧效率在当量比处于0 .1～ 0 .9范围时高于 0 .92 ,在极小当量比时由于未燃混合气淬熄 ,在当量比时由于过度分层而使燃烧效率降低。根据燃烧产物计算的燃烧效率与根据放热分析获得的燃烧效率一致。因此 ,天然气直喷分层燃烧在宽广的当量比范围内可望实现高效燃烧火花助燃发动机的宽广的高效燃烧。
The feasibility of direct injection stratified combustion of natural gas by using rapid compression device was studied. The results show that the stratified combustion of natural gas has short initial flame development period and main combustion period and high combustion pressure. Stratified combustion lean burn limit extends to a very small equivalence ratio. As a result of over-stratification, the CO increases sharply at an equivalence ratio greater than 0.8, and the peak of NOx also appears at a small equivalence ratio due to delamination. The combustion efficiency is higher than 0.92 when the equivalence ratio is in the range of 0.1 to 0.9, and the combustion efficiency is reduced due to excessive delamination at the equivalence ratio due to quenching of the unburnt gas mixture at the extremely equivalent ratio. The combustion efficiency calculated from the combustion products is consistent with the combustion efficiency obtained from the exothermic analysis. Therefore, direct injection stratified combustion of natural gas is expected to achieve broad and efficient combustion of a highly efficient combustion spark-assisted combustion engine over a wide equivalence ratio.