| 摘要 |
<p>An engine management system (36) regulates the quantity of fuel supplied to the cylinders of an internal combustion system having an NOX trap (38) in its exhaust. The NOx trap (38) contains materials which absorb NOx produced during lean fuelling and release NOx during rich fuelling. In a lean burn mode the engine (10) is run with a lean air/fuel ratio with intermittent purge operations. Each purge operation includes cycles (46, 47, 48) of alternate rich and lean fuelling, to give more efficient and cleaner purges.</p> |
