다탄소알코올/경유 혼합 연료를 사용한 직분사식 디젤 엔진의 연소 특성 연구

다국어 초록 (Multilingual Abstract)

Alcohol, an oxygenated fuel, is a renewable fuel that can be originated from biomass and is effective in reducing pollutants from internal combustion engines. There have been many studies on the combustion characteristics of lower alcohols in diesel engines, but information on higher alcohols is relatively scarce. In this study, n-butanol, n-pentanol, n-octanol, and n-decanol were respectively added to diesel fuel to investigate the combustion and emission characteristics of a single-cylinder 4-stroke diesel engine. The concentration of each alcohol in the fuel blends was 10%, 30%, and 50% by volume. Experiments were conducted by varying the engine torque from 4 Nm to 12 Nm at the same engine speed of 1700 rpm. Results show the increasing trends of the brake thermal efficiencies with diesel/n-butanol and diesel/n-pentanol blends, but decreasing trends with diesel/n-octanol and diesel/n-decanol blends. The brake specific fuel consumption(BSFC) increased for all kinds of diesel/alcohol blends compared to standard diesel fuel. The concentration of nitrogen oxides(NOx) was generally reduced, but the trend of change in NOx concentration according to the proportion of alcohol was different. The concentration of carbon monoxide(CO) shows a similar tendency for standard diesel fuel and diesel/alcohol blends under the condition of brake mean effective pressure(BMEP) of 0.33 MPa or less but shows different trends according to the type of alcohol under the condition of BMEP of 0.42 MPa or higher. The concentration of unburned hydrocarbon (HC) increased significantly with diesel/n-butanol and diesel/n-pentanol blends with the alcohol proportion was 30% or higher, but the HC emissions are slightly reduced with diesel/n-octanol and diesel/n-decanol blends. Smoke opacity was reduced with all kinds of diesel/alcohol blends in all test conditions compared to standard diesel fuel, and the reduction rate of smoke opacity increased as the proportion of alcohol increased. To compare the performance of diesel engines, the maximum brake power was measured in the engine speed range of 1400-2500 rpm under full load conditions. Results show that the maximum brake power was the highest in standard diesel fuel, and the power decreased as the proportion of alcohol increased. The lowest power was measured with an alcohol proportion of 50% for all kinds of alcohols, and diesel/n-butanol blends generated the lowest power among alcohols

목차 (Table of Contents)

• Ⅰ. 서론 1
• Ⅱ. 실험 장치 및 방법 6
• 1. 실험 장치 6
• 2. 실험 방법 8
• Ⅲ. 실험 결과 및 고찰 10
• 1. 알코올 혼합 연료에 따른 디젤 엔진 출력 특성 10
• 2. 연소 특성 12
• 2.1 Brake thermal efficiency(BTE, 열효율) 12
• 2.2 Brake specific fuel consumption(BSFC, 제동연료소비율) 및 brake specific energy consumption(BSEC, 제동에너지소비율) 14
• 3. 알코올 연료에 따른 배기 특성 17
• 3.1 Nitrogen oxides (NOx, 질소산화물) 배출특성 및 배기온도 17
• 3.2 Carbon monoxide(CO, 일산화탄소) 배출 특성 20
• 3.3 Unburned hydrocarbon(HC, 미연 탄화수소) 배출 특성 23
• 3.4 Smoke opacity(스모크 불투명도) 특성 25
• Ⅳ. 결론 27