Method for monitoring the nitrogen oxide storage capacity of a nitrogen oxide storage catalyst used in the form of a primary catalytic converter
    1.
    发明授权
    Method for monitoring the nitrogen oxide storage capacity of a nitrogen oxide storage catalyst used in the form of a primary catalytic converter 有权
    监测以一级催化转化器形式使用的氮氧化物储存催化剂的氮氧化物储存能力的方法

    公开(公告)号:US08230674B2

    公开(公告)日:2012-07-31

    申请号:US11722135

    申请日:2005-12-17

    IPC分类号: F01N3/00

    摘要: Modern exhaust-gas purification systems in motor vehicles with a lean-burn engine include a starting catalyst fitted close to the engine and a main catalyst arranged in the underbody region, with both the starting catalyst and the main catalyst being formed by nitrogen oxide storage catalysts. The nitrogen oxide storage catalysts are in each case regenerated by the engine being briefly switched from lean-burn mode to rich-burn mode when the nitrogen oxide concentration in the exhaust gas downstream of the storage catalysts rises above a predetermined value.The starting catalyst is exposed to particularly high temperatures and is therefore prone to faster ageing of its nitrogen oxide storage capacity than the main catalyst. To check the nitrogen oxide storage capacity of the starting catalyst, a regeneration which is due for the catalyst system is selected in such a way in terms of its duration and the extent to which the exhaust gas is enriched that substantially only the starting catalyst is regenerated, whereas the main catalyst is not. In this arrangement, the criterion for terminating this partial regeneration is the breakthrough of rich exhaust gas through the starting catalyst. After the engine has been switched back to lean-burn mode, the time which elapses until the concentration of nitrogen oxides in the exhaust gas downstream of the catalyst requires regeneration again is measured. The measured time is a measure of the remaining nitrogen oxide storage capacity of the starting catalyst.

    摘要翻译: 具有稀燃燃烧发动机的机动车辆中的现代废气净化系统包括安装在发动机附近的起动催化剂和布置在底体区域中的主催化剂,起始催化剂和主催化剂由氮氧化物储存催化剂形成 。 当存储催化剂下游的废气中的氮氧化物浓度升高到预定值以上时,氮氧化物储存催化剂在每种情况下都可通过发动机从稀燃模式短暂切换为富燃模式。 起始催化剂暴露于特别高的温度,因此比主催化剂容易发生氮氧化物储存容量的老化。 为了检查起始催化剂的氮氧化物存储容量,选择催化剂体系所致的再生,就其持续时间和废气浓缩程度而言,基本上只有起始催化剂被再生 ,而主催化剂不是。 在这种布置中,终止这种部分再生的标准是通过起动催化剂的富排气的突破。 在发动机已经切换回稀燃模式之后,测量在催化剂下游的废气中的氮氧化物浓度再次需要再次之前经过的时间。 测量时间是起始催化剂的剩余氮氧化物储存容量的量度。

    Method for regenerating nitrogen oxide storage catalysts
    2.
    发明授权
    Method for regenerating nitrogen oxide storage catalysts 有权
    氮氧化物储存催化剂再生方法

    公开(公告)号:US07905087B2

    公开(公告)日:2011-03-15

    申请号:US11995765

    申请日:2006-06-22

    IPC分类号: F01N3/00

    摘要: Nitrogen oxide storage catalytic converters for purifying the exhaust gas of lean-burn engines are periodically regenerated by switching the engine from lean-burn mode to rich-burn mode. After regeneration has taken place, the engine is switched back to lean-burn mode. At this time, rich exhaust gas is still flowing in the exhaust line from the engine to the catalytic converter, which rich exhaust gas is ejected via the catalytic converter into the environment by the following, lean exhaust gas. This leads to brief emissions peaks of the rich exhaust gas constituents and impairs the level of exhaust gas cleaning which can be obtained. In order to solve said problem, it is proposed to create oxidizing conditions by injecting air upstream of the storage catalytic converter, so that the rich exhaust gas constituents still flowing in the exhaust line upstream of the storage catalytic converter can be converted at the storage catalytic converter to form non-harmful products. The proposed method can lead to a considerable improvement in exhaust gas purification in particular in the case of catalytic converters which are already impaired in terms of their storage capacity through aging, and which must be regenerated significantly more frequently than fresh catalytic converters.

    摘要翻译: 通过将发动机从稀燃模式切换到富燃烧模式,周期性地再生用于净化贫燃发动机废气的氧化氮储存催化转化器。 发生再生后,发动机切换回稀燃模式。 此时,排气管道中的废气仍然从发动机流向催化转化器,其中,废气通过下列稀释废气通过催化转化器排放到环境中。 这导致了丰富的废气成分的短暂的排放峰值,并损害了可以获得的废气净化水平。 为了解决上述问题,提出了通过在储存催化转化器的上游喷射空气来产生氧化条件,使得能够在储存催化转化器的上游排出的排气管中仍然流动的富排气成分在储存催化剂 转换器形成无害产品。 所提出的方法可以导致废气净化的显着改进,特别是在催化转化器的情况下,其通过老化而在储存容量方面已经受损,并且必须比新鲜催化转化器显着更频繁地再生。

    Method for regeneration a nitrogen oxide storage catalyst
    3.
    发明授权
    Method for regeneration a nitrogen oxide storage catalyst 有权
    再生氮氧化物储存催化剂的方法

    公开(公告)号:US07832201B2

    公开(公告)日:2010-11-16

    申请号:US11722149

    申请日:2005-12-24

    IPC分类号: F01N3/00

    摘要: To remove the nitrogen oxides from the exhaust gas from lean-burn engines, these engines are equipped with a nitrogen oxide storage catalyst, which has to be regenerated frequently by the engine being briefly switched to rich-burn mode. The regeneration is usually initiated when the nitrogen oxide concentration downstream of the catalyst rises above a permissible value. In this context, there is a risk of the bed temperature of the catalyst during and after regeneration being pushed into a range with incipient thermal desorption of the nitrogen oxides on account of the heat which is released during the conversion of the nitrogen oxides by the reducing constituents of the exhaust gas. This can lead to increased nitrogen oxide emission both during the regeneration itself and after the engine has been switched back to lean-burn mode. To eliminate this problem, it is proposed to divide the rich-burn mode into two rich pulses which follow one another in time, the first rich pulse being of shorter duration than the second rich pulse.

    摘要翻译: 为了从贫燃发动机的排气中除去氮氧化物,这些发动机配备有氮氧化物储存催化剂,其必须经过发动机的短时间切换为富燃烧模式而频繁地再生。 当催化剂下游的氮氧化物浓度高于允许值时,通常开始再生。 在这种情况下,存在在再生期间和之后将催化剂的床温度推到具有氮氧化物的初期热解吸的范围内的风险,这是由于在氮氧化物转化期间释放的热量通过还原 排气成分。 这可以导致在再生期间和发动机已经切换回稀燃模式之后氮氧化物排放增加。 为了消除这个问题,提出将富燃烧模式分成时间上相互依赖的两个富脉冲,第一富脉冲的持续时间比第二富脉冲短。

    Method for Regenerating Nitrogen Oxide Storage Catalysts
    4.
    发明申请
    Method for Regenerating Nitrogen Oxide Storage Catalysts 有权
    再生氮氧化物储存催化剂的方法

    公开(公告)号:US20090145112A1

    公开(公告)日:2009-06-11

    申请号:US11995765

    申请日:2006-06-22

    IPC分类号: F01N9/00

    摘要: Nitrogen oxide storage catalytic converters for purifying the exhaust gas of lean-burn engines are periodically regenerated by switching the engine from lean-burn mode to rich-burn mode. After regeneration has taken place, the engine is switched back to lean-burn mode. At this time, rich exhaust gas is still flowing in the exhaust line from the engine to the catalytic converter, which rich exhaust gas is ejected via the catalytic converter into the environment by the following, lean exhaust gas. This leads to brief emissions peaks of the rich exhaust gas constituents and impairs the level of exhaust gas cleaning which can be obtained. In order to solve said problem, it is proposed to create oxidizing conditions by injecting air upstream of the storage catalytic converter, so that the rich exhaust gas constituents still flowing in the exhaust line upstream of the storage catalytic converter can be converted at the storage catalytic converter to form non-harmful products. The proposed method can lead to a considerable improvement in exhaust gas purification in particular in the case of catalytic converters which are already impaired in terms of their storage capacity through aging, and which must be regenerated significantly more frequently than fresh catalytic converters.

    摘要翻译: 通过将发动机从稀燃模式切换到富燃烧模式,周期性地再生用于净化贫燃发动机废气的氧化氮储存催化转化器。 发生再生后,发动机转回稀燃模式。 此时,排气管道中的废气仍然从发动机流向催化转化器,其中,废气通过下列稀释废气通过催化转化器排放到环境中。 这导致了丰富的废气成分的短暂的排放峰值,并损害了可以获得的废气净化水平。 为了解决上述问题,提出了通过在储存催化转化器的上游喷射空气来产生氧化条件,使得能够在储存催化转化器的上游排出的排气管中仍然流动的富排气成分在储存催化剂 转换器形成无害产品。 所提出的方法可以导致废气净化的显着改进,特别是在催化转化器的情况下,其通过老化而在储存容量方面已经受损,并且必须比新鲜催化转化器显着更频繁地再生。

    Method for monitoring the nitrogen oxide storage capacity of a nitrogen oxide storage catalyst used in the form of a primary catalytic converter
    5.
    发明申请
    Method for monitoring the nitrogen oxide storage capacity of a nitrogen oxide storage catalyst used in the form of a primary catalytic converter 有权
    监测以一级催化转化器形式使用的氮氧化物储存催化剂的氮氧化物储存能力的方法

    公开(公告)号:US20090229249A1

    公开(公告)日:2009-09-17

    申请号:US11722135

    申请日:2005-12-17

    IPC分类号: F01N11/00 G01M15/10

    摘要: Modern exhaust-gas purification systems in motor vehicles with a lean-burn engine include a starting catalyst fitted close to the engine and a main catalyst arranged in the underbody region, with both the starting catalyst and the main catalyst being formed by nitrogen oxide storage catalysts. The nitrogen oxide storage catalysts are in each case regenerated by the engine being briefly switched from lean-burn mode to rich-burn mode when the nitrogen oxide concentration in the exhaust gas downstream of the storage catalysts rises above a predetermined value.The starting catalyst is exposed to particularly high temperatures and is therefore prone to faster ageing of its nitrogen oxide storage capacity than the main catalyst. To check the nitrogen oxide storage capacity of the starting catalyst, a regeneration which is due for the catalyst system is selected in such a way in terms of its duration and the extent to which the exhaust gas is enriched that substantially only the starting catalyst is regenerated, whereas the main catalyst is not. In this arrangement, the criterion for terminating this partial regeneration is the breakthrough of rich exhaust gas through the starting catalyst. After the engine has been switched back to lean-burn mode, the time which elapses until the concentration of nitrogen oxides in the exhaust gas downstream of the catalyst requires regeneration again is measured. The measured time is a measure of the remaining nitrogen oxide storage capacity of the starting catalyst.

    摘要翻译: 具有稀燃燃烧发动机的机动车辆中的现代废气净化系统包括安装在发动机附近的起动催化剂和布置在底体区域中的主催化剂,起始催化剂和主催化剂由氮氧化物储存催化剂形成 。 当存储催化剂下游的废气中的氮氧化物浓度升高到预定值以上时,氮氧化物储存催化剂在每种情况下都可通过发动机从稀燃模式短暂切换为富燃模式。 起始催化剂暴露于特别高的温度,因此比主催化剂容易发生氮氧化物储存容量的老化。 为了检查起始催化剂的氮氧化物存储容量,选择催化剂体系所致的再生,就其持续时间和废气浓缩程度而言,基本上只有起始催化剂被再生 ,而主催化剂不是。 在这种布置中,终止这种部分再生的标准是通过起动催化剂的富排气的突破。 在发动机已经切换回稀燃模式之后,测量在催化剂下游的废气中的氮氧化物浓度再次需要再次之前经过的时间。 测量时间是起始催化剂的剩余氮氧化物储存容量的量度。

    Method for regeneration a nitrogen oxide storage catalyst
    6.
    发明申请
    Method for regeneration a nitrogen oxide storage catalyst 有权
    再生氮氧化物储存催化剂的方法

    公开(公告)号:US20090151329A1

    公开(公告)日:2009-06-18

    申请号:US11722149

    申请日:2005-12-24

    IPC分类号: F01N9/00

    摘要: To remove the nitrogen oxides from the exhaust gas from lean-burn engines, these engines are equipped with a nitrogen oxide storage catalyst, which has to be regenerated frequently by the engine being briefly switched to rich-burn mode. The regeneration is usually initiated when the nitrogen oxide concentration downstream of the catalyst rises above a permissible value. In this context, there is a risk of the bed temperature of the catalyst during and after regeneration being pushed into a range with incipient thermal desorption of the nitrogen oxides on account of the heat which is released during the conversion of the nitrogen oxides by the reducing constituents of the exhaust gas. This can lead to increased nitrogen oxide emission both during the regeneration itself and after the engine has been switched back to lean-burn mode. To eliminate this problem, it is proposed to divide the rich-burn mode into two rich pulses which follow one another in time, the first rich pulse being of shorter duration than the second rich pulse.

    摘要翻译: 为了从贫燃发动机的排气中除去氮氧化物,这些发动机配备有氮氧化物储存催化剂,其必须经过发动机的短时间切换为富燃烧模式而频繁地再生。 当催化剂下游的氮氧化物浓度高于允许值时,通常开始再生。 在这种情况下,存在在再生期间和之后将催化剂的床温度推到具有氮氧化物的初期热解吸的范围内的风险,这是由于在氮氧化物转化期间释放的热量通过还原 排气成分。 这可以导致在再生期间和发动机已经切换回稀燃模式之后氮氧化物排放增加。 为了消除这个问题,提出将富燃烧模式分成时间上相互依赖的两个富脉冲,第一富脉冲的持续时间比第二富脉冲短。