| 摘要 |
Various example approaches are described, one of which includes a method for controlling injection of gaseous and liquid fuel to a cylinder during engine starting. Specifically, gaseous fuel is injected during or before an intake stroke of the cycle to form a well-mixed overall lean air-fuel mixture, and then liquid fuel is directly injected to the cylinder at least during one of a compression and expansion stroke of the engine cycle to form a rich air-fuel cloud near the spark plug, where a spark initiates combustion of the injected fuels. In one example, the rich cloud enables additional spark retard, and thus faster catalyst light-off, while maintain acceptable combustion stability of the gaseous fuel. |
