Two-stage Fuel Direct Injection in a Diesel Fuelled HCCI Engine
Two-stage Fuel Direct Injection in a Diesel Fuelled HCCI Engine
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柴油 HCCI 发动机中的两级燃油直喷
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
C. Bae
中科院分区：
文献类型：
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作者：
Haiyun Su;S. Mosbach;M. Kraft;A. Bhave;S. Kook;C. Bae
双级燃油直喷技术具有扩大柴油均质压燃（HCCI）发动机工作范围和控制自燃提前角的潜力。在这项工作中，研究双喷射HCCI燃烧，随机反应器模型，基于概率密度函数（PDF）的方法，被利用。在直接喷射随机喷雾模型中引入了一个新的碰壁子模型。然后，对四冲程HCCI发动机上进行的燃烧参数和排放测量的模型进行验证。数值模拟的初步结果表明，在一定的工况条件下，两级喷射能够利用局部富油颗粒触发充量点火，从而延长HCCI的工作范围。此外，模拟和实验结果表明，存在一个最佳的第二喷射定时，以获得最大的发动机输出功，对于给定的燃料分流比的第二喷射定时对燃烧的影响。
Two-stage fuel direct injection (DI) has the potential to expand the operating region and control the autoignition timing in a Diesel fuelled homogeneous charge compression ignition (HCCI) engine. In this work, to investigate the dual-injection HCCI combustion, a stochastic reactor model, based on a probability density function (PDF) approach, is utilized. A new wall-impingement sub-model is incorporated into the stochastic spray model for direct injection. The model is then validated against measurements for combustion parameters and emissions carried out on a four stroke HCCI engine. The initial results of our numerical simulation reveal that the two-stage injection is capable of triggering the charge ignition on account of locally rich fuel parcels under certain operating conditions, and consequently extending the HCCI operating range. Furthermore, both simulated and experimental results on the effect of second injection timing on combustion indicate that there exists an optimal second injection timing to gain maximum engine output work for a given fuel split ratio.