1994 Fiscal Year Final Research Report Summary
Development of a Premixture Combustion Type Diesel Engine Using a Microhole Injection Nozzle
| Project/Area Number |
04555047
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thermal engineering
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
KAMIMOTO Takeyuki Tokyo Inst.of Tech.Faculty of Eng, Professor, 工学部, 教授 (00016429)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAMURA Hideo Isuzu Ceramics Research Inst.Co., LTD,Director, セラミックス研究所, 取締役
IIDA Norimasa Keio Univ., Faculty of Science and Eng, Associate Professor, 理工学部, 助教授 (60137982)
IKEGAMI Makoto Kyoto Univ., Faculty of Eng, Professor, 工学部, 教授 (70025914)
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| Project Period (FY) |
1992 – 1994
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| Keywords | Microhole nozzle / Laser Drilling / High Pressure Fuel Injection / Diesel Combustion / Exhaust Emissions |
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| Research Abstract |
The objective of this study is to reduce the soot and NOx emissions from diesel engines keeping the thermal efficiency high. For this purpose, we proposed a new combustion concept of diesel engines, which burns premixture like more uniform mixtures than that of conventional diesel combustion. This concept will be achieved by a combination of a multiple micro-hole nozzle, having an orifice diameter of one tenth of that of the conventional nozzle, with high-pressure fuel injection system. In this study, the following results were obtained :
(1) We succeeded to make the multiple micro-hole nozzle with an orifice diameter of 0.06 mm by a laser drilling.
(2) The effects of orifice size on ignition delay and combustion were investigated using a rapid compression and expansion machine which has a combustion chamber with a bore size of 60 mm. The measurement results showed that decreasing orifice diameter from 0.15 mm to 0.06 mm shortens the ignition delay by 30% in a wide range of ambient pressure of 2.8MPa-8.5MPa. The measurement of combustion behavior with a micro-hole nozzle in a DI engine was also carried out and the results revealed that the ignition delay is shortened and smoke emission is reduced, but NOx emission is not reduced.
(3) A high-pressure diesel fuel injection system using spool acceleration and oil hammering was developed, and the performance of this injector was investigated. The results demonstrated that it is possible to control the initial injection rate and achieve the pilot-injection by changing the pre-lift of spool and double-acceleration of spool. This injection system was found useful for the study of the effect of injection rate on the formation of mixture in a spray flame with a micro-hole nozzle.
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