Method for operating a nitrogen oxide storage catalyst in a diesel engine
    22.
    发明授权
    Method for operating a nitrogen oxide storage catalyst in a diesel engine 有权
    在柴油发动机中操作氮氧化物储存催化剂的方法

    公开(公告)号:US07670577B2

    公开(公告)日:2010-03-02

    申请号:US12090936

    申请日:2006-10-19

    IPC分类号: B01D53/56 B01D53/94

    CPC分类号: F01N3/0871 Y02T10/20

    摘要: A nitrogen oxide storage catalytic converter which is operated for a relatively long time at low exhaust-gas temperatures in the range between 120 and 250° C. exhibits a decreasing storage capacity as a result of incomplete regeneration at said temperatures. In order to re-establish the original storage capacity of the catalytic converter which is operated in this way, two-stage regeneration is proposed, wherein the storage catalytic converter is initially partially regenerated at the low exhaust gas temperature by means of a switch from the lean mode to the rich mode, and wherein subsequently, with rich exhaust gas again, the exhaust-gas temperature of the engine is raised into a range of between 300 and 400° C. for complete regeneration.

    摘要翻译: 在120-250℃的低废气温度下操作较长时间的氮氧化物储存催化转化器,由于在所述温度下的不完全再生,表现出降低的储存能力。 为了重新建立以这种方式运行的催化转化器的原始储存能力,提出了两级再生,其中储存催化转化器最初在低废气温度下部分地通过从 稀模式到富模式,并且随后再次具有浓排气,发动机的排气温度升高到300-400℃之间,以完全再生。

    METHOD FOR THE REACTIVATION OF THERMALLY AGED NITROGEN OXIDE STORAGE CATALYTIC CONVERTERS
    23.
    发明申请
    METHOD FOR THE REACTIVATION OF THERMALLY AGED NITROGEN OXIDE STORAGE CATALYTIC CONVERTERS 有权
    热老化氧化物储存催化转化器的反应方法

    公开(公告)号:US20090131243A1

    公开(公告)日:2009-05-21

    申请号:US11995590

    申请日:2006-07-15

    IPC分类号: B01J38/06

    摘要: Nitrogen oxide storage catalysts are used for removing the nitrogen oxides present in the lean-burn exhaust gas of lean-burn engines. Here, the purifying action is based on the nitrogen oxides being stored in the form of nitrates by the storage material of the storage catalyst during a lean-burn operating phase of the engine and the previously formed nitrates being decomposed in a subsequent rich-burn operating phase of the engine and the nitrogen oxides which are being liberated again being reacted with the reducing exhaust gas constituents over the storage catalyst to form nitrogen, carbon dioxide and water. Storage catalysts are thermally aged by high temperatures. The aging is due to sintering of the catalytically active noble metal components of the catalyst and to formation of compounds of the storage components with the support materials. According to the invention, the formation of compounds of the storage materials can be largely reversed by treatment of the storage material with a gas mixture comprising nitrogen dioxide and/or carbon dioxide and water vapor at temperatures of from 300 to 500° C. The reactivation can be carried out either directly on the vehicle by setting appropriate exhaust gas conditions or during a routine service by removal of the catalyst from the vehicle and treatment with a gas mixture in an appropriate apparatus.

    摘要翻译: 氮氧化物储存催化剂用于除去贫燃发动机的稀燃废气中存在的氮氧化物。 这里,净化作用是基于在发动机的稀薄燃烧操作阶段期间由储存催化剂的储存材料以硝酸盐的形式储存的氮氧化物,并且先前形成的硝酸盐在随后的富燃烧操作中被分解 再次释放的发动机和氮氧化物的相与还原废气成分反应,形成氮气,二氧化碳和水。 储存催化剂通过高温热老化。 老化是由于催化剂的催化活性贵金属组分的烧结以及用载体材料形成储存组分的化合物。 根据本发明,存储材料的化合物的形成可以通过在包含二氧化氮和/或二氧化碳和水蒸汽的气体混合物中在300-500℃的温度下处理储存材料而大大地逆转。再活化 可以直接在车辆上进行,通过设定适当的废气条件或者在例行服务期间通过从车辆中除去催化剂并在合适的装置中用气体混合物进行处理。

    Method for Operating a Nitrogen Oxide Storage Catalytic Converter in a Motor Vechicle with Consideration of Regional Fuel Qualities
    24.
    发明申请
    Method for Operating a Nitrogen Oxide Storage Catalytic Converter in a Motor Vechicle with Consideration of Regional Fuel Qualities 审中-公开
    在考虑区域燃料质量的汽车机器中操作氮氧化物储存催化转化器的方法

    公开(公告)号:US20080314030A1

    公开(公告)日:2008-12-25

    申请号:US12158099

    申请日:2006-11-22

    IPC分类号: F01N9/00

    摘要: The fuel qualities for vehicles differ, for example, in Europe on a regional basis. This applies in particular to the sulphur content of the fuel. If vehicles with modern lean engines or with diesel engines which are equipped with nitrogen oxide storage-type catalytic converters in order to reduce the nitrogen oxide content in their exhaust gas pass through regions with a sulphur content in the fuel which is above the sulphur content which is specified for the vehicle, the engine controller will correspondingly frequently initiate desulphurization of the storage-type catalytic converter after the vehicle has been refuelled with this fuel. Any desulphurization entails an increased level of fuel consumption and greater ageing of the catalytic converter. It is proposed to avoid these adverse effects in that in lean motors the engine controller switches to stoichiometric operation in such a case, and in a diesel engine said engine controller prevents the desulphurization. The information about the region in which the vehicle is moving at a particular time can be transmitted to the engine controller by a navigation system.

    摘要翻译: 车辆的燃料质量在欧洲区域不同。 这尤其适用于燃料的硫含量。 如果配备有氮氧化物存储型催化转化器以减少其废气中的氮氧化物含量的现代精益发动机或柴油发动机的车辆通过燃料中硫含量高于硫含量的区域 为车辆指定,发动机控制器将相应地频繁地启动储存型催化转化器在车辆加油之后的脱硫。 任何脱硫都需要增加燃料消耗水平和催化转化器的老化。 建议避免在这种情况下,在稀薄电动机中,发动机控制器切换到化学计量操作的这些不利影响,并且在柴油发动机中,所述发动机控制器防止脱硫。 关于车辆在特定时间移动的区域的信息可以由导航系统发送到发动机控制器。

    EXHAUST EMISSION CONTROL SYSTEM FOR LEAN ENGINES AND METHOD FOR OPERATING THE SYSTEM
    28.
    发明申请
    EXHAUST EMISSION CONTROL SYSTEM FOR LEAN ENGINES AND METHOD FOR OPERATING THE SYSTEM 审中-公开
    排气发动机排气控制系统及运行系统的方法

    公开(公告)号:US20100037597A1

    公开(公告)日:2010-02-18

    申请号:US12519989

    申请日:2007-12-21

    IPC分类号: F01N9/00 F01N3/023 F01N3/10

    摘要: An emission control system for the cleaning of the exhaust gases of a lean burn engine with two or more cylinders comprises a first exhaust leg for the exhaust gases of a first group of cylinders and a second exhaust leg for the exhaust gases of a second group of cylinders. A nitrogen oxide storage catalyst is arranged in each exhaust leg. The two exhaust legs are combined downstream of the storage catalysts at a confluence to form a common exhaust leg. The common exhaust leg contains an SCR catalyst. The first and second groups of cylinders are each supplied alternately in periodic intervals with lean and rich air/fuel mixtures. Lean or rich exhaust gases are thus obtained in the combustion in the cylinders and released into the corresponding exhaust legs. Lean and rich exhaust gases are adjusted with respect to one another so as to result in a lean exhaust gas after the combination of the exhaust gases in the common exhaust leg. The regeneration of the storage catalysts may result in the formation of ammonia, which is stored by the SCR catalyst and reacted with nitrogen oxides which pass through the storage catalysts in an unwanted manner during the storage phases.

    摘要翻译: 用于清洁具有两个或多个气缸的稀薄燃烧发动机的废气的排放控制系统包括用于第一组气缸的排气的第一排气支管和用于第二组气缸的废气的第二排气支管 气瓶。 在每个排气支管中设置氮氧化物储存催化剂。 两个排气支路在汇合处在储存催化剂的下游组合以形成共同的排气支路。 普通排气支架含有SCR催化剂。 第一组和第二组汽缸分别以稀薄和浓缩的空气/燃料混合物以周期性间隔交替供应。 因此,在气缸中的燃烧中获得精益或浓缩的废气,并将其排放到相应的排气支管中。 精益和丰富的废气相对于彼此进行调节,以便在共同排气支路中排出的废气组合之后产生贫乏的废气。 储存催化剂的再生可导致氨的形成,其由SCR催化剂储存并与在储存阶段期间以不期望的方式通过储存催化剂的氮氧化物反应。

    Method for monitoring the nitrogen oxide storage capacity of a nitrogen oxide storage catalyst used in the form of a primary catalytic converter
    29.
    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
    30.
    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。