• 한국분무공학회지
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• 제17권4호
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• pp.178-184
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• 2012

The aim of this study was to compare the spray characteristics of a typical fuel (100% diesel, DME) and diesel-DME blended fuel in a constant volume combustion chamber (CVCC). The typical fuel (100% diesel, DME) and diesel-DME blended fuel spray characteristics were investigated at various ambient pressures (pressurized nitrogen) and fuel injection pressures using a common rail fuel injection system when the fuel mixture ratio was varied. The fuel injection quantity and spray characteristics were measured including spray shape, penetration length, and spray angle. Common types of injectors were used.

• 한국자동차공학회논문집
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• 제21권4호
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• pp.1-7
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• 2013

DME spray characteristics were investigated about varied ambient pressure and fuel injection pressure using the DME common rail fuel injection system when the nozzle holes diameter is varied. The common rail fuel injection system with DME cooling system was used since DME has properties of compressibility and vaporization in atmospheric temperature. The fuel injection quantity and spray characteristics were measured. The spray analysis parameters were spray shape, penetration length, and spray angle at six nozzle holes. Three types of injector were used, the nozzle holes diameter were 0.166 mm (Injector 1), 0.250 mm (Injector 2), and 0.250 mm with enlargement of orifice hole from 0.6 mm to 1.0 mm (Injector 3). The fuel injection pressure was varied by 5MPa from 35 to 70MPa when the ambient pressure was varied 0, 2.5, and 5MPa. When using Injector 3 in comparison to the others, the DME injection quantity was increased 1.69 ~ 2.02 times. Through this, it had the similar low heat value with diesel which was injected Injector 1. Among three types of injector, Injector 3 had the fastest development velocity of penetration length. In case of spray angle, Injector 2 had the largest spray angle. Through these results, only the way enlargement the nozzle holes diameter is not the solution of DME low heat value problem.

• 한국자동차공학회논문집
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• 제20권2호
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• pp.90-97
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• 2012

It is investigated of the DME spray characteristics about varied ambient pressure and fuel injection pressure using the common rail fuel injection system when the nozzle holes diameter is varied. The common rail fuel injection system and fuel cooling system is used since DME has compressibility and vaporization in atmospheric temperature. The fuel injection quantity and spray characteristics were measured. The spray was analyzed of spray shape, penetration length, and spray angle at the six nozzle holes. The 2 types injector were used, the one was 0.166 mm diameter the other one was 0.250 mm diameter. The ambient pressure which is based on gage pressure was 0 MPa, 2.5 MPa, and 5 MPa. The fuel injection pressure was varied by 5 MPa from 35 MPa to 70 MPa. When using the converted injector, compared to using the common injector, the DME injection quantity was increased 127 % but it didn't have the same heat release. Both of the common and converted injector had symmetric spray shapes. In case of converted injector, there were asymmetrical spray shapes until 1.2 ms, but after 1.2 ms the spray shape was symmetrical. Compared with the common and converted injector, the converted injector had shorter penetration length and wider spray angle than the common injector.

• 한국산학기술학회논문지
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• 제14권7호
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• pp.3127-3134
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• 2013

본 연구는 DME 연료를 사용할 수 있도록 변경된 엔진의 제어 알고리즘, 로직구성 및 차량상태에서 검증결과를 나타낸 것으로써, 제어구조 및 자동코드 생성기법에 의한 제어로직 설계과정과 제어 맵을 소개하고 최종적으로 제어의 신뢰성 및 성능을 검증한 것이다. 제어구조는 운전자 요구를 엔진발생토크로 구현하기위한 분사제어부와 배기가스 및 동력특성을 만족시키기 위한 공기제어 시스템부로 크게 구성되며, 제어로직은 제어응답성을 향상시키기 위하여 각 제어 기능별로 앞먹임 및 뒤먹임 제어부로 설계되었고, 앞먹임 제어부의 제어 맵은 엔진모델을 이용하여 생성한 뒤, 이를 엔진 및 차량 시험과정에서 보정하였다. 개발된 제어기를 장착하여 차량 시험모드를 완주하였으며, EGR, VGT 및 분사시기 보정에 의하여 배출가스 저감효과를 확인하였다.