• 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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• 제11권2호
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• pp.75-82
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• 2003

DME is a good alternative fuel to reduce the smoke remarkably when used in a diesel engine, while problems concerned with low lubricity and high compressibility exist. In the present study, single cylinder DI diesel engine was operated with neat DME and DME blended fuels which are DME-diesel blended fuel and DME-propane blended fuel. The results showed that the power of the neat DME and DME blended fuels was the same as that of pure diesel oil, and the specific energy consumption slightly increased. In addition, smoke emission was considerably reduced with the increase of DME content up to zero level, but NOx emission was slightly increased.

• 한국분무공학회지
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• 제18권2호
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• pp.73-80
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• 2013

The purpose of this study was compared the spray, combustion and emissions (NOx, CO, HC, smoke) characteristics of a typical fuel (100% Diesel, DME) and Diesel-DME blended fuel in a Constant Volume Chamber (CVC) and a single-cylinder DI diesel engine. Spray characteristics were investigated under various ambient and fuel injection pressures when the Diesel-DME blended ratio is varied. The parameters of spray sturdy were spray shape, penetration length, and spray angle. Common types of injectors having seven holes and made by Bosch were used. As of use, the typical fuel (100% Diesel, DME) and the blended fuel by mixture ratio 95:5, 90:10 (Diesel:DME) were used. The Injection pressure was fixed by 70.1MPa, when the ambient Pressure was varied 0.1, 2.6 and 5.1 MPa. The combustion experiments was conducted with single cylinder engine equipped with common rail injection system. injection pressure is 70 MPa. The amount of injected fuels is adjusted to obtain the fixed input calorie value as 972.2 J/cycle in order to compare with the fuel conditions.

• 한국수소및신에너지학회논문집
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• 제23권5호
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• pp.530-537
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• 2012

This work experimentally investigates that Diesel-DME blended fuel influences combustion characteristics and emissions (NOx, CO, HC, smoke) in a single-cylinder DI diesel engine. Diesel is used as a main fuel and DME is blended for the use of its quick evaporating characteristics. Diesel and DME are blended by the method of weight ratio. Weight ratios for Diesel and DME are 95:5 and 90:10 respectively and the both ratios have been used altogether in blended fuel. The experiments are conducted in this study single cylinder engine is equipped with common rail and injection pressure is 700 bar at 1200 rpm. The amount of injected fuels is adjusted to obtain the fixed input calorie value as 972.2 J/cycle in order to compare with the fuel conditions. DME is compressed to 15 bar by using nitrogen gas thus it can be maintained the liquid phase. In this study, different system compared others paper is common rail system, also there is combustion and emission about compared DME and diesel fuel. It is expected to be utilized about blended fuel.

• 에너지공학
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• 제24권4호
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• pp.33-41
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• 2015

DME는 높은 세탄가와 낮은 배출가스로 인하여 청정 디젤엔진 대체연료로 사용될 수 있고, LPG와 물리적 특성이 유사하기 때문에 혼합사용이 가능하다. 본 연구에서는 DME-LPG 혼합연료를 LPG 차량 연료에 적용한 실증평가를 수행하였다. 평가 차량으로는 LPG 연료 공급방식별로 액상연료공급방식(LPLi), 기상연료공급방식(LPGi), 분배식펌프 방식(Mixer type)의 LPG 자동차를 선택하였다. 배출가스(CO, THC, $NO_X$)와 연료소비효율에 대한 영향을 비교하기 위하여 LPG와 DME-LPG 혼합연료에 대한 성능평가를 수행하였다. 차량의 주행거리가 증가함에 따라 DME-LPG 혼합연료를 사용한 차량의 배출가스와 연료소비효율은 LPG 연료를 사용한 경우와 비교해서 동등한 수준으로 평가되었다.

• 한국자동차공학회논문집
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• 제17권5호
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• pp.53-60
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• 2009

In this study, LPG-blended DME fuel was experimentally investigated in CI(compression ignition) engine. In particular, performance, emissions characteristics (including hydrocarbon, CO, and NOx emissions), and combustion stability of engine fueled with LPG-blended DME fuel were examined. The extent of LPG fuel in the blended fuel was 0-40 wt%. Results showed that stable engine operation was possible in a wide range of engine loads on DME blended with maximum 30% of LPG by mass in a CI engine. Considering the results of the engine power output and exhaust emissions, blended fuel up to 30% of LPG by mass can be used as an alternative to diesel in a CI engine. LPG blended DME fuel is expected to have potential for enlarging the DME market.

• 한국자동차공학회논문집
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• 제22권4호
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• pp.55-64
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• 2014

This work was investigated on pilot injection strategy of blended fuels(Diesel-DME) for combustion and emissions in a single cylinder direct injection compression ignition engine. Diesel and DME were blended by the method of weight ratio. Weight ratios for diesel and DME were 95:05 and 90:10 respectively. dSOI between main and pilot injection timing was varied. A total amount of injected fuels(single injection) was adjusted to obtain the fixed BMEP as 4.2 bar in order to compare with the fuel conditions. Also, the amount of pilot injection fuel was varied by 5%, 10% and 20% of total injection fuel. The engine was equipped with common rail and injection pressure is 700 bar at 1200 rpm. As a result, when mixing ratio increase, indicated thermal efficiency was increased in comparison with DD 100 and CO, THC and smoke were lower than DD 100. The influence of reducing NOx by pilot injection was more effective than DD 100. When pilot injection quantity increase, abrupt increase of NOx was occured at pilot injection quantity of 20%.

• 한국분무공학회지
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• 제11권3호
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• pp.140-146
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• 2006

The objective of this work is to analyze the atomization and evaporation characteristics of dimethyl ether(DME) fuel for the application of HCCI diesel engine. In order to investigate the spray behavior of DME fuel, the macroscopic and microscopic characteristics were investigated in terms of spray development, spray tip penetration, impingement time, SMD, and axial mean velocity under the various injection timing and ambient conditions. For the illumination of spray, the spray visualization system was composed of a Nd:YAG laser and an ICCD camera and laser-sheet method was used. The atomization characteristics of DME fuel are analyzed by using phase Doppler particle analyzer (PDPA) system It was reveal that the spray development of DME is slower and rapidly disappeared as elapsed time after start of injection at the same injection duration. The impingement timing of diesel fuel was fester than that of DME fuel. The comparison of spray atomization characteristics in both fuels shows that diesel fuel has a large SMD value that DME.

• 한국자동차공학회논문집
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• 제14권4호
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• pp.84-91
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• 2006

In this study, the effect of EGR and fuel injection pressure on the characteristics of combustion and emission performance of the common-rail diesel engine is investigated using DME fuel as a smoke-free alternative fuel. Because the heating value and density of DME fuel are lower than those of diesel fuel, the injection duration of the DME engine is relatively longer than the injection duration of the diesel engine with the same injection pressure. However, the higher injection pressure can shorten the injection duration for the DME engine. Although the smoke level of the DME engine is much lower than that of the diesel engine, the NOx is at a level similar to that of the diesel engine. As a proposed solution for this, the EGR technique is empirically applied to the DME engine. In the experiments, the injection pressure was changed from 200bar to 400bar, and the EGR rate was limited under 40%. With the same injection timing and fuel amount, the experiment results indicated that the increase of injection pressure led to the increase of IMEP while decreasing HC and CO emissions. However, the NOx emission tends to increase as the injection pressure becomes higher. On the other hand, as the EGR rate was increased, NOx emission and A/F were reduced while the HC and CO emissions were increased. Because HC and CO emissions have the critical A/F point where the emissions of HC and CO are rapidly increased, it is proposed that the EGR rate must be limited under the critical EGR rate.

• 해양환경안전학회지
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• 제16권3호
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• pp.301-306
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• 2010

DME는 환경 친화적인 특성으로 인해 현재 전 세계적으로 주목을 받고 있다. 지금까지 DME는 매연을 적게 생산하는 청정 에너지라는 특성으로 인해 디젤 자동차의 주요 대체 에너지로서 연구되어 왔다. 이에 본 연구에서는 에틸렌 대향류 확산화염에 DME를 5%, 14% 및 30% 혼합했을 때, DME의 혼합 비율에 따른 매연의 수밀도 및 크기에 대한 영향을 조사하였다. 레이저 투과법 및 산란법을 이용해 수밀도 및 크기를 측정하였다. 그 결과 DME를 30% 혼합한 경우에는 매연이 감소한 반면, 5%와 14%의 혼합 비율에서는 매연이 증가하는 경향을 나타내었다. 이 결과는 DME가 매연 생성이 적은 청정 연료로 알려진 것과는 달리 에틸렌 확산화염 내에서는 DME의 혼합에 따라 매연 생성이 증가될 수 있다는 것을 의미한다.