Effect of mixture strength and injection timing on combustion characteristics of a direct injection hydrogen-fueled engine
Effect of mixture strength and injection timing on combustion characteristics of a direct injection hydrogen-fueled engine
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DOI：
10.1016/j.ijhydene.2013.01.092
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发表时间：
2013-03
影响因子：
7.2
通讯作者：
K. Hamada;M. Rahman;M. A. Abdullah;R. A. Bakar;A. Aziz
中科院分区：
文献类型：
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作者：
K. Hamada;M. Rahman;M. A. Abdullah;R. A. Bakar;A. Aziz
对火花点火直喷式发动机氢燃烧特性进行了试验研究。重点研究了混合气浓度和喷射时刻对氢气燃烧特性的影响。为此，在实验测试台上进行了实际测试。它最初是为优化直喷天然气发动机而设计的。试验台的试验结果包括不同工况下缸内压力、已燃质量分数和放热率的变化曲线。结果表明，混合气浓度越高，各测点的压力趋势越大。除此之外，由于火焰速度的增加，它表现出更快的燃烧速率的增加速率。然而，燃烧特性恶化，由于缺乏混合气分层与较早的喷射定时。得出的结论是，直喷定时是必不可少的，以实现更好的燃烧性能。此外，延迟火花点火正时对于避免在较浓混合气的情况下的异常燃烧和喷射的早期开始也是至关重要的。
An experimental investigation was performed to characterize the hydrogen combustion in a spark-ignition direct-injection engine. It was focused on the effects of mixture strength and injection timing on the characteristics of hydrogen combustion. For this purpose, the practical tests were carried out on an experimental test rig. It is originally designed for optimization of the direct-injection natural-gas engine. The experimental test-rig results comprised the traces for the in-cylinder pressure, mass fraction burned, and heat release rate under the different operation conditions. The results obtained show that the richer mixture condition produced higher pressure trends at all tested points. Besides that, it exhibited a faster rate of increase in combustion rate due to the increase of flame speed. However, the combustion characteristics deteriorated due to the lack of mixture stratification with earlier injection timing. It is concluded that direct-injection timing is essential to achieve better combustion performance. Moreover, retarding the spark ignition timing is also crucial to avoid abnormal combustion in the case of a richer mixture and early start on injection.