摘要 |
Over a lower part of the power range from tick over up to a transition point, engine power is varied by varying the quantity of the main injection and there after the main injection of fuel is supplemented by a secondary introduction of the same or a different fuel. With secondary fuel introduction the main injection timing is progressively retarded to compensate for reduced ignition delay. The secondary fuel introduction may be in the form of vapourised fuel injected onto an exhaust gas recirculation valve (Fig. 8) or a glow plug in the intake manifold (Fig. 9). |