Studies of multi-channel spark ignition of lean n-pentane/air mixtures in a spherical chamber
Studies of multi-channel spark ignition of lean n-pentane/air mixtures in a spherical chamber
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DOI：
10.1016/j.combustflame.2019.11.022
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发表时间：
2020-01
影响因子：
4.4
通讯作者：
Hao Zhao;Ningbo Zhao;Tianhan Zhang;Shuqun Wu;Guoming Ma;Chao Yan;Y. Ju
中科院分区：
文献类型：
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作者：
Hao Zhao;Ningbo Zhao;Tianhan Zhang;Shuqun Wu;Guoming Ma;Chao Yan;Y. Ju
本文提出了一种新颖的多通道火花点火策略。与典型的单火花点火技术相比，三通道火花点火技术使三个空间分离和时间同步的放电在保持总点火能量不变的情况下增加了点火核尺寸。研究了稀正戊烷/空气混合气在不同放电距离、不同压力和不同CO2稀释度的球形燃烧室中的三通道放电特性、着火核发展和着火概率，并与单通道火花进行了比较。实验结果表明，在所有试验条件下，与单通道放电相比，三通道火花提高了点火概率，并显著延长了贫油点火极限。此外，多通道火花的着火强化效果随着压力的降低、放电间隙的减小和CO2稀释度的增加而增大。采用详细的正戊烷动力学模型(Bugler等人，2017)进行了一维数值模拟，结果表明，使用多通道火花使燃料稀薄点火概率增加和最小点火能量降低是点火核尺寸比最小临界点火半径增大的结果。这项研究证实了在先进的低燃料内燃机上使用多通道火花的优势。
A novel ignition strategy using multi-channel sparks was developed in this paper. Compared with the typical single spark, the three-channel spark ignition technique enables three spatially separated and temporally synchronized discharges to increase the ignition kernel size while maintaining the same total ignition energy. The three-channel discharge characteristics, ignition kernel development, and ignition probability of lean n-pentane/air mixtures were studied and compared with those of single-channel spark in a spherical combustion chamber with different discharge distances, pressures, and CO2dilution levels. The experimental results show that the three-channel sparks increase the ignition probability and dramatically extend the fuel-lean ignition limits compared to the single-channel discharge under all tested conditions. Moreover, ignition enhancement effects of multi-channel sparks increase with the decrease of pressure, reduction of discharge gap, and increase of CO2dilution. One-dimensional numerical simulation was performed by using a detailed n-pentane kinetic model (Bugler et al., 2017) and the results revealed that the increase of fuel lean ignition probability and the decrease of the minimum ignition energy by using multi-channel sparks were the outcome of increased ignition kernel size compared to the minimum critical ignition radius. This present study confirms the advantages of using multi-channel sparks on advanced fuel-lean combustion engines.