CAI combustion of gasoline and its mixture with ethanol in a 2-stroke poppet valve DI gasoline engine
CAI combustion of gasoline and its mixture with ethanol in a 2-stroke poppet valve DI gasoline engine
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DOI：
10.1016/j.fuel.2013.03.002
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发表时间：
2013-07
期刊：
影响因子：
7.4
通讯作者：
Yan Zhang;Hua Zhao;M. Ojapah;A. Cairns
中科院分区：
文献类型：
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作者：
Yan Zhang;Hua Zhao;M. Ojapah;A. Cairns
可控自动点火（CAI），又称均质充量压缩点火（HCCI），是降低汽车燃油消耗和氮氧化物排放的最有前途的燃烧技术之一。目前，CAI燃烧仅限于部分负荷工况，低负荷时容易发生失火，高负荷时容易发生爆震燃烧，且缺乏有效的燃烧过程控制手段。如何将CAI发动机的工作范围从高负荷向满负荷扩展，从低负荷向怠速扩展，使其满足整车循环的要求，已成为CAI/HCCI技术产业化面临的关键问题之一。此外，这种燃烧模式应该与不同的燃料兼容，并且在必要时可以切换回传统的火花点火操作。在本文中，CAI操作演示了一个二冲程汽油直喷（GDI）发动机配备了一个提升阀机构。结果表明，在二冲程循环中，可容易地实现CAI燃烧，并且与四冲程循环操作相比，CAI燃烧的范围可显著地扩展。此外，还研究了乙醇浓度对二冲程CAI工作范围、燃烧过程、排放和效率的影响。
Controlled Auto Ignition (CAI), also known as Homogeneous Charge Compression Ignition (HCCI), is one of the most promising combustion technologies to reduce the fuel consumption and NOx emissions. Currently, CAI combustion is constrained at part load operation conditions because of misfire at low load and knocking combustion at high load, and the lack of effective means to control the combustion process. Extending its operating range including high load boundary towards full load and low load boundary towards idle in order to allow the CAI engine to meet the demand of whole vehicle driving cycles, has become one of the key issues facing the industrialisation of CAI/HCCI technology. Furthermore, this combustion mode should be compatible to different fuels, and can switch back to conventional spark ignition operation when necessary. In this paper, the CAI operation is demonstrated on a 2-stroke gasoline direct injection (GDI) engine equipped with a poppet valve train. The results shown that the CAI combustion can be readily achieved in the 2-stroke cycle of a poppet valve engine and the range of CAI combustion can be significantly extended compared to the 4-stroke cycle operation. In addition, the effects of ethanol concentration on 2-stroke CAI operational range, combustion process, emissions and efficiencies are studied and presented.