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均质混合气压燃(HCCI)燃烧受爆震和NO_x排放的限制,高负荷拓展是一个难题。本文提出利用理论空燃比SICI组合燃烧作为汽油机中高负荷运行区域的高效低污染燃烧模式。在试验台架上研究了理论空燃比SICI组合燃烧的排放特性及其对三效催化剂(TWC)转换性能的影响。研究发现,通过外部EGR与点火控制相结合,理论空燃比SICI组合燃烧可以在指示平均有效压力(IMEP)0.65～0.82MPa范围内稳定实现;与传统SI燃烧相比,理论空燃比SICI组合燃烧燃油经济性提高近10%,NO_x排放降低80%以上,但HC排放有所增加;SICI组合燃烧与传统SI燃烧类似,TWC空燃比特性的高效区间在理论空燃比附近,但对HC排放的催化能力提出了更高的要求。
Homogeneous mixed-pressure combustion (HCCI) combustion by knocking and NO_x emissions limit, high-load expansion is a problem. In this paper, a high efficiency and low pollution combustion mode using the combined SICI combustion of the theoretical air-fuel ratio as the high-load operating region of the gasoline engine is proposed. The emission characteristics of the stoichiometric SICI combustor combustion and its effect on the conversion performance of a three-way catalyst (TWC) were investigated on a test bench. The results show that the combination of external EGR and ignition control can stably achieve the stoichiometric air-fuel ratio (SICI) combination combustion within the range of 0.65-0.82MPa, indicating the mean effective pressure (IMEP). Compared with the conventional SI combustion, the stoichiometric SICI combustion fuel The economy improved by nearly 10%, NO_x emission decreased by more than 80%, but the HC emission increased. The combustion of SICI combustor was similar to that of conventional SI combustion. The high efficiency range of TWC was close to the theoretical air-fuel ratio, but the catalytic capacity of HC emission Put forward higher requirements.