| 摘要 |
Introducing gaseous fuel upstream of an intake valve displaces air with fuel leading to reduced power. Pressurizing gaseous fuel to introduce only after an intake valve closes requires special equipment increasing engine cost and time required to pressurize fuel. A method and apparatus are disclosed for introducing gaseous fuel into a combustion chamber of an engine. The method comprises dividing the engine map into three distinct operating regions. When operating in a low load region, gaseous fuel is introduced to the combustion chamber during an intake stroke before an intake valve closes. When operating in a high load, low-speed region, gaseous fuel is directly injected during a compression stroke after the intake valve is closed. When operating in a high load, high-speed region, gaseous fuel is introduced both before and after the intake valve closes. |
