空气/天然气λ对QHCCI燃烧过程影响的研究

A STUDY OF OPTIMIZATION OF THE AIR/FUEL RATIO AND IT'S EFFECT ON EXHAUST EMISSIONS OF A CNG PORT INJECTION QHCCI ENGINE

本文采用天然气气口顺序喷射、柴油引燃方式实现了基于天然气的准均质压燃着火燃烧过程（ＱＨＣＣＩ），本文研 究了气口喷射天然气／空气过量空气系数（λ）ＱＨＣＣＩ对燃烧过程的影响，分析了各种排放产物及燃油经济性同过量空气 系数（λ）、停缸数和引燃柴油量的关系。通过燃烧优化，发动机ＮＯｘ、颗粒和ＮＭＨＣ排放均达到了欧Ⅱ排放指标。

A QHCCI combustion process is realized by through sequential port injection of CNG, and electronically controlled diesel injection as pilot ignited fuel. The effects of A on combustion is studied in detail in this paper. for QHCCI combustion process, soot emission is greatly reduced and mainly depended on the quantity of diesel pilot injection, which keeps the feature of rich diffusion combustion. In addition to that the quantity of pilot diesel is also a strong fact effects NOx emission. As expected, as λ ...