Downsized-Boosted Gasoline Engine with Exhaust Compound and Lean Advanced Combustion
This article presents the experimental results obtained with a disruptive engine platform, designed to maximize the engine efficiency through a synergetic implementation of downsizing, high compression-ratio, and importantly exhaust-heat energy recovery in conjunction with advanced lean/dilute low-temperature type combustion. The engine architecture is a supercharged high-power output, 1.1-liter engine with two-firing cylinders and a high compression ratio of 13.5:1. The integrated exhaust heat recovery system is an additional, larger displacement, non-fueled cylinder into which the exhaust gas from the two firing cylinders is alternately transferred to be further expended. The main goal of this work is to implement advanced lean/dilute combustion while minimizing NOx emissions and addressing the transition between the operating modes. The combustion modes include well-mixed charge compression-ignition at low-load, and a mixed-mode combustion strategy at higher loads.