| 摘要 |
Gaseous fuel. eg hydrogen, and intake air are delivered to a first intake port 252 of a cylinder of an i.c. engine and intake air without gaseous fuel is delivered to a second intake port 250 of the cylinder, the first port 252 separated from the second port 250. Further, the method includes inducting the fuel and intake air from the first port via a first intake valve 222, and the intake air from the second port via a second intake valve 220, where the first intake valve 222 is opened after, eg 20 to 60 crank degrees after, the second intake valve 220. The gaseous fuel may be delivered into the first port 252 by an injector 260 located downstream of the bifurcation of the intake ports 250, 252. The gaseous fuel thus enters the cylinder after the residual gas and hot metal have been cooled by the fuel-free air, reducing the likelihood of backfire. A variable cam timing system may be used to adjust valve opening timing and injection timing depending on judged potential for backfire. |
