| 摘要 |
<p>The present invention is particularly well suited for purifying exhaust from relatively large lean burn diesel engines. A computer controlled injector (20) intermittently injects an optimal amount of NOx reducing fluid into the exhaust passageway (11) from the engine (12). The optimal amount corresponds to an amount that will achieve optimal NOx reduction rates for the given engine operating condition and exhaust temperature. A computer (16) periodically senses the engine operating condition and the exhaust temperature, and calculates the appropriate injection amount. With appropriate deNOx and oxidation catalysts located downstream from the injector (20), the exhaust purification system (10) of the present invention has the ability to greatly reduce NOx content of the exhaust while maintaining HC emissions at acceptable levels.</p> |
