Intake charge dilution effects on control of nitric oxide emission in a hydrogen fueled SI engine
Intake charge dilution effects on control of nitric oxide emission in a hydrogen fueled SI engine
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DOI：
10.1016/j.ijhydene.2006.09.039
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发表时间：
2007-08
影响因子：
7.2
通讯作者：
V. Subramanian;J. Mallikarjuna;A. Ramesh
中科院分区：
文献类型：
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作者：
V. Subramanian;J. Mallikarjuna;A. Ramesh
虽然氢燃料火花点火发动机可以在高的热效率下运行，HC和CO的排放几乎为零，但高水平的NOx暴露问题。燃烧温度高和使用的混合气稀薄是原因。本文研究了进气中添加N2、CO2和热EGR气体作为稀释剂对歧管喷射氢燃料点燃式发动机NO排放的影响。氮气作为稀释剂在低负荷时不那么有效，同时引入少量，但在较高负荷时非常有效，其中混合物变得更富，稀释效果（氧气消耗）显著。另一方面，二氧化碳是一种良好的稀释剂，具有相对较好的热效应和稀释效应，在所有输出区域都能有效控制NO排放。然而，这是以牺牲热效率为代价的。再循环的热废气既含有N2又含有蒸汽，其效率介于N2和CO2之间。总的来说，N2是最有效的，因为对于给定的允许NO排放水平，它对热效率的影响最小。因此，冷EGR可能是一个很好的选择。在所有情况下，一个良好的控制系统是必要的，以提供正确数量的稀释剂。
Though hydrogen fueled spark ignition engine can operate at high thermal efficiency with almost zero emission of HC and CO, the high level of NOxposes problems. The high combustion temperature and lean mixtures used are the reasons. In this work, the effect of N2, CO2and hot EGR gas as diluents in the intake charge to suppress NO emission in a manifold injected hydrogen fueled SI engine was studied. Nitrogen as a diluent is not so effective at low loads while inducting smaller amounts, but very effective at higher loads where the mixture becomes richer and the dilution effect (oxygen depletion) is significant. On other hand, carbon dioxide is a good diluent with relatively better thermal effect and diluent effect and effectively controls NO emission at all output regions. However this is at the expense of thermal efficiency. Recirculating hot exhaust gas which contains both N2and steam comes in between N2and CO2in terms of its effectiveness. On the whole N2is the most effective as it has minimum impact on thermal efficiency for a given level of permissible NO emission. Thus it is felt that cold EGR could be a good option. In all cases, a good control system is necessary to supply correct quantity of diluent.