Effect of glycerol ethoxylate as an ignition improver on injection and combustion characteristics of hydrous ethanol under CI engine condition
Effect of glycerol ethoxylate as an ignition improver on injection and combustion characteristics of hydrous ethanol under CI engine condition
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DOI：
10.1016/j.enconman.2015.03.116
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发表时间：
2015-07
影响因子：
10.4
通讯作者：
Ronnachart Munsin;Y. Laoonual;S. Jugjai;M. Matsuki;H. Kosaka
中科院分区：
文献类型：
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作者：
Ronnachart Munsin;Y. Laoonual;S. Jugjai;M. Matsuki;H. Kosaka
研究了乙氧基甘油作为点火改进剂在电喷发动机上对含水乙醇喷射和燃烧特性的影响。在快速压缩膨胀机(RCEM)上进行了喷雾燃烧试验，并利用基于Zeuch法的喷油速率测量装置研究了喷油特性。在RCEM中，喷油正时为21℃、4.4℃和900℃时，CI发动机的状态分别为压缩合成气的密度、压力和温度，其中80%的Ar和20%的氧气。这种情况相当于压缩比为22的实际CI发动机的空气等熵压缩。不含点火改进剂的含水乙醇(Eh95)和重型汽车专用乙醇(ED95：由含水乙醇和ED95商用添加剂组成)分别代表了电控发动机的低质量乙醇燃料和高质量乙醇燃料。所有的测试燃料都是在恒定的热输入下注入的。结果表明，添加点火改进剂改变了喷油特性，即喷油延迟期、喷油速率和含水乙醇的排放系数。重型汽车专用乙醇(ED95)和含5%甘油聚氧乙烯醚的含水乙醇(含5%GE)的全开针最大喷射速率比不含点火改进剂的含水乙醇(Eh95)低约10%。ED95和5%GE需要额外的喷射持续时间才能保持恒定的能量输入。点火改进剂显著改善了EH95的着火延迟期和放热率。点火改进剂对火焰温度的影响不大。KL系数与光路中的碳烟排放量大致成正比，测量的碳烟排放量受这些改进剂的影响。
This paper investigates the effects of glycerol ethoxylate as an ignition improver on injection and combustion characteristics of hydrous ethanol under a CI engine condition. Injection characteristics were investigated by an in-house injection rate measurement device based on the Zeuch method, while spray combustion has been performed in the rapid compression and expansion machine (RCEM). The CI engine condition indicated as density, pressure and temperature of compressed synthetic gas, consisting of 80% argon and 20% oxygen, at fuel injection timing in RCEM of 21 kg/m3, 4.4 MPa and 900 K, respectively. This condition is equivalent to the isentropic compression of air of the actual CI engine with compression ratio of 22. Hydrous ethanol without ignition improver (Eh95) and the ethanol dedicated for heavy duty vehicles (ED95: composed of hydrous ethanol with the commercial additive for ED95) are reference fuels representing low and high quality ethanol fuel for CI engines, respectively. All test fuels are injected at constant heat input. The results indicate that the additional ignition improvers change injection characteristics, i.e. injection delay, injection rate and discharge coefficient of hydrous ethanol. The maximum injection rates at fully opened needle for the ethanol dedicated for heavy duty vehicles (ED95) and hydrous ethanol with 5% glycerol ethoxylate (5%GE) are lower than that of hydrous ethanol without ignition improver (Eh95) by approximately 10%. Additional injection duration is required for ED95 and 5%GE to maintain a constant energy input. Ignition delay and heat release rate of Eh95 are significantly improved by ignition improvers. The effect of ignition improvers on flame temperature is minor. KL factor, which is approximately proportional to soot amount in the optical path, and the measured soot emission, are affected by these improvers.