著者

段 智久 橋本 正孝 浅野 一郎 奥村 哲平 鈴木 直樹

出版者

公益社団法人 日本マリンエンジニアリング学会

雑誌

マリンエンジニアリング (ISSN:13461427)

巻号頁・発行日

vol.44, no.2, pp.322-327, 2009 (Released:2012-04-20)

参考文献数

9

被引用文献数

3 3

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DME is the simplest ether and consists of oxygen and methyl. Because of its chemical and physical properties it is thought that DME could be one of the candidates as an alternative fuel in the internal combustion engine. The authors have been investigating the combustion characteristics of the mixed fuel comprising of Dimethyl ether and Marine Diesel Oil (JIS A-heavy oil). In the experiments, DME is mixed at the liquefied state with MDO inside a high pressure fuel tank pressured with nitrogen gas. Fuel supply lines are replaced with pressure resistant tubes, and the mixed fuel is supplied to the small direct injection diesel engine. We obtained the effect on the fuel injection characteristics to the mixed fuel combustion, in the diesel engine. The two different fuel injection rates are obtained by changing the injection nozzle opening pressure, that for the relatively lower case (9.0MPa) and higher (24.0MPa). The fuel injection pressure histories and the combustion characteristics, such as the combustion pressure and the exhaust emission, are examined for both the injection conditions. The average injection pressure increased with increased engine load in the lower nozzle opening pressure case. Whilst it is almost constant with the higher nozzle opening pressure case. It was concluded that ignition delay could be shortened by DME mixing. And NOx emissions were reduced in the higher engine load case, and with mixing DME for both nozzle opening pressure cases.

著者

橋本 正孝 段 智久 浅野 一朗 大谷 友人

出版者

公益社団法人 日本マリンエンジニアリング学会

雑誌

マリンエンジニアリング (ISSN:13461427)

巻号頁・発行日

vol.44, no.3, pp.456-462, 2009 (Released:2012-06-02)

参考文献数

3

被引用文献数

2 2

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Palm oil is being seriously looked at as one of the alternative fuels to fossil fuels, this being due to the aspect of vegetable oils and the so called carbon neutral state. However, at room temperature, the viscosity of palm oil is too high to apply as a fuel for the internal combustion engine. In this study, pure palm oil is mixed with fossil fuels, this in order to reduce the viscosity. In the experiment palm oil was blended with gas oil and then marine diesel oil, by weight ratio, and the kinematic viscosity of the mixed fuels were measured. In the cases of 20% palm oil used, and 50%, was found to be useable without any heating of the fuels. Engine performances, such as cylinder pressure histories and exhaust emissions, were examined with a pre-combustion chamber type diesel engine. We discovered that a palm oil blended fuel shows earlier ignition and shorter combustion period than gas oil or marine diesel oil. NOx emissions show a lower concentration for all palm blended cases, and the reduction ratio is proportional to the palm mixing amount. From these results, we can suggest that palm oil could be used for the diesel engine by mixing with the fossil fuels without heating the fuels.

著者

段 智久 橋本 正孝 浅野 一朗 中村 卓朗

出版者

The Japan Institute of Marine Engineering

雑誌

マリンエンジニアリング (ISSN:13461427)

巻号頁・発行日

vol.41, no.3, pp.438-443, 2006-05-01 (Released:2010-05-31)

参考文献数

6

被引用文献数

1

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Dimethyl Ether (DME) was mixed with waste vegetable oil to improve combustion and exhaust emissions in a high speed diesel engine. Past research has shown that the properties of DME, such as lower boiling point and higher cetane number, would affect atomization process and combustion progress of DME/Marine diesel oil blending fuel. In this study, the effect of mixing DME with waste vegetable oil was investigated by using the 4-stroke single cylinder direct injection diesel engine. The combustion pressure history, injection pressure, exhaust gas emissions were measured in variation with mixing ratio of DME and engine load. The emissions of smoke and nitrogen oxide were found to reduce with increase in mixing ratio of DME.

著者

段 智久 橋本 正孝 浅野 一朗 山縣 正史

出版者

The Japan Institute of Marine Engineering

雑誌

マリンエンジニアリング (ISSN:13461427)

巻号頁・発行日

vol.39, no.6, pp.409-414, 2004-06-01 (Released:2010-05-31)

参考文献数

2

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We improved the system of a high-speed single-acting 4-stroke diesel engine to allow it run on a mixed fuel comprised of A-heavy oil and DME (Di-Methl Ether), fuel components that discharge no soot, no SOx, and little NOx in combustion. The combustion pressure, rate of heat release, exhaust gas components, and other conditions were measured in experiments using diesel oil, A-heavy oil, and the mixed fuel comprised of DME and A-heavy oil.As a result, the ignition timing was earliest with diesel oil, median with the mixed fuel, and latest with A-heavy oil. Mixed fuel discharged a slightly reduced level of NOx. Overall, results indicated that the engine would require further improvements before long-term operation became possible.