著者

石田 正弘 陳 之立 植木 弘信 山田 武

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.61, no.590, pp.3518-3523, 1995-10-25 (Released:2008-03-28)

参考文献数

11

被引用文献数

1

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To reduce the level of exhaust emissions and to improve the ignition characteristics, the effect of pilot injection on combustion was examined experimentally in a turbocharged direct-injection diesel engine, and was analyzed theoretically using a two-zone combustion model. The pilot injection effect was compared with the combustion in the injection without pilot injection and also with the effect of fuel additive as an ignition improver in two kinds of fuel : high-quality fuel having a cetane index of 57 and low-quality fuel having that of 40. It is found that the pilot injection effectively reduces ignition delay at the retarded injection timing, under the low-load condition, and in the case of low-cetane fuel. The ignition delay of the main injection is reduced to about a half of that of the injection without pilot injection by the pilot injection with the short interval between pilot and main injection. The ignition delay of the low-cetane fuel is reduced to that of the high-quality fuel by a small amount of pilot injection, or by adding 1% of the ignition improver.

著者

山本 昌平 坂口 大作 植木 弘信 石田 正弘

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集B編 (ISSN:18848346)

巻号頁・発行日

vol.79, no.799, pp.380-389, 2013 (Released:2013-03-25)

参考文献数

16

被引用文献数

5

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In order to realize a premixed compression ignition (PCI) engine by utilizing bio-alcohol, combustion characteristics of bio-alcohol blended with gas oil were compared between ethanol and n-butanol in a diesel engine. The effects of the ethanol blend ratio and the butanol blend ratio on ignition delay, premixed combustion, diffusion combustion, fuel consumption and exhaust emissions such as smoke density, nitrogen oxide (NOx) and so on were investigated experimentally. It is found that ethanol almost burns out together with low evaporation temperature composition of gas oil in the premixed combustion period and the heat release in the diffusion combustion is based on mainly high evaporation temperature composition of gas oil, then, soot is formed in the diffusion combustion of gas oil. On the other hand, a part of butanol burns in the diffusion combustion, and the combustion of butanol in the diffusion stage is not the cause of soot formation. Butanol is more useful in diesel engine compared with ethanol because butanol can be blended with gas oil without surface-active agent, and fuel consumption and smoke are almost equal in both blend fuels if the alcohol blend ratio is the same.