公开(公告)号：WO1996005417A1

公开(公告)日：1996-02-22

申请号：PCT/US1995010151

申请日：1995-08-08

Applicant: CATERPILLAR INC.

Inventor： CATERPILLAR INC. ,  LANE, William, H. ,  LEARNED, Daniel, J. ,  PETERSON, Randy, N. ,  SMITH, Aaron, L. ,  WHITE, Scott, T.

IPC: F01N03/28

CPC classification number: F01N3/2867 ,  B01D53/9409 ,  B01D53/9454 ,  B01D53/9472 ,  F01N3/2066 ,  F01N3/2828 ,  F01N3/2857 ,  F01N13/0097 ,  F01N13/017 ,  F01N2570/14 ,  F01N2610/03 ,  Y02A50/2344 ,  Y02T10/22 ,  Y02T10/24

Abstract: The present invention is particularly applicable to lean burn engines that produce exhaust containing insufficient amounts of unburned hydrocarbons to satisfactorily reduce NOx emissions without undermining engine performance. In the exhaust purification system (10), ethanol or another suitable hydrocarbon (19) is injected into the exhaust stream at an appropriate location between the engine and the catalytic converter (12). A deNOx catalytic converter (22, 122, 222) is positioned within the exhaust downstream from the ethanol injection point. The combination engine application, ethanol injection and suitable deNOx catalyst combine to reduce NOx to satisfactory levels without producing significant amounts of undesirable secondary nitrogen containing compounds. An oxidation catalytic converter (24, 124, 224) is positioned in the exhaust downstream from the deNOx catalytic converter (22, 122, 222). The oxidation catalyst serves to convert any remaining unburned hydrocarbons (19) into carbon dioxide and water. At the same time, only small amounts of secondary nitrogen compounds are converted back into NOx compounds upon passage through the oxidation catalyst. The end result being an overall reduction in both HC and NOx compounds particularly for lean burn engines to satisfactory levels.

Abstract translation: 本发明特别适用于生产含有不足量未燃碳氢化合物的排气的稀薄燃烧发动机，以令人满意地减少NOx排放而不损害发动机的性能。 在排气净化系统（10）中，在发动机和催化转化器（12）之间的适当位置将乙醇或其它合适的烃（19）注入废气流中。 脱硝催化转化器（22,122,222）位于乙醇注入点下游的排气口内。 组合发动机应用，乙醇注射和合适的脱硝催化剂组合以将NOx降低至令人满意的水平，而不产生显着量的不期望的次级含氮化合物。 氧化催化转化器（24,124,224）位于脱气催化转化器（22,122,222）下游的废气中。 氧化催化剂用于将任何剩余的未燃烧的烃（19）转化为二氧化碳和水。 同时，只有少量的次级氮化合物在通过氧化催化剂时转化回NOx化合物。 最终的结果是HC和NOx化合物的整体减少，特别是对于稀薄燃烧发动机，达到令人满意的水平。

公开(公告)号：WO1996006270A1

公开(公告)日：1996-02-29

申请号：PCT/US1995009955

申请日：1995-08-07

Applicant: CATERPILLAR INC.

Inventor： CATERPILLAR INC. ,  LANE, William, H. ,  PETERSON, Randy, N. ,  SMITH, Aaron, L. ,  WHITE, Scott, T. ,  LEARNED, Daniel, J.

IPC: F01N03/20

CPC classification number: F01N9/00 ,  B01D53/9495 ,  F01N3/2066 ,  F01N2260/024 ,  F01N2560/06 ,  F01N2570/14 ,  F01N2610/03 ,  F01N2610/08 ,  F01N2610/11 ,  F01N2610/146 ,  F01N2900/08 ,  Y02A50/2344 ,  Y02T10/22 ,  Y02T10/24 ,  Y02T10/47

Abstract: 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.

Abstract translation: 本发明特别适用于从相对较大的稀燃柴油发动机中净化废气。 计算机控制的喷射器（20）从发动机（12）间歇地将最优量的NOx还原流体喷射到排气通道（11）中。 最佳量对应于对于给定的发动机操作条件和排气温度将达到最佳NOx还原速率的量。 计算机（16）周期性地检测发动机工作状态和排气温度，并计算适当的喷射量。 利用位于喷射器（20）下游的合适的脱硝和氧化催化剂，本发明的排气净化系统（10）具有大大降低废气中的NOx含量的能力，同时将HC排放保持在可接受的水平。