Low compression ratio diesel engines fueled with biodiesel by using spark-induced compression ignition
Low compression ratio diesel engines fueled with biodiesel by using spark-induced compression ignition
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DOI：
10.1177/1468087414542888
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发表时间：
2015-06
影响因子：
2.5
通讯作者：
K. Yamane;Chihiro Kondo;Daichi Kondo;K. Kawasaki
中科院分区：
文献类型：
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作者：
K. Yamane;Chihiro Kondo;Daichi Kondo;K. Kawasaki
本研究的目的是展示一种新颖的燃烧系统，在该系统中，在低压缩比的直喷柴油发动机中，通过火花放电进入在长点火延迟时间内形成的预混合物中，从而引发自燃。通过改变火花正时、喷射正时、当量比和燃油量，研究了火花放电对自燃过程的影响。使用的燃料是月桂酸甲酯，这是一种脂肪酸甲酯，相对易挥发，并且比标准柴油具有更高的点火质量。单缸共轨直喷柴油机的结果表明，火花诱导压缩点火燃烧的容积效率为34%。在这项研究中，自燃正时通过火花放电提前，并通过火花正时控制在5°曲柄角内。我们还通过光学带通滤波器、图像增强器和电荷耦合器件相机的组合，使用直接高速摄影和 OH 自由基化学发光光谱观察了定容燃烧容器中的火花诱导压缩点火燃烧火焰。结果表明，火花诱导压缩点火不是通过火花点火引起的火焰传播发生的，而是通过喷雾预混合物的自燃发生的。还明显的是，自燃是由喷射流在火花塞处形成的 OH 自由基的传输引起的。
The objective of this study was to demonstrate a novel combustion system in which autoignition is induced by spark discharge into a pre-mixture formed during a long ignition delay time in a direct injection diesel engine with a low compression ratio. The effects of spark discharge on the autoignition process were investigated by changing the spark timing, injection timing, equivalence ratio and fuel amount. The fuel used was lauric acid methyl ester, a fatty acid methyl ester that is relatively volatile and exhibits higher ignition quality than standard diesel fuel. The results obtained with a single-cylinder common-rail direct injection diesel engine show that spark-induced compression ignition combustion was obtained with a volumetric efficiency of 34%. In this study, the autoignition timing was advanced by spark discharge and was controlled by the spark timing within 5° crank angle. We also observed the spark-induced compression ignition combustion flame in a constant volume combustion vessel using direct high-speed photography and OH radical chemiluminescence spectroscopy by means of a combination of an optical band-pass filter, an image intensifier and a charge-coupled device camera. The results showed that spark-induced compression ignition occurs not by flame propagation due to spark ignition but by autoignition of a spray pre-mixture. It was also evident that autoignition is induced by transportation of OH radicals formed at the spark plug by the spray flow.