REDUCTION OF EMISSIONS WITH PROPANE ADDITION TO A DIESEL ENGINE

다국어 초록 (Multilingual Abstract)

Recent studies on dual-fuel combustion in compression–ignition (CI) engines, also known as diesel engines,fall into two categories. In the first category are studies focused on the addition of small amounts of gaseous fuel to CI engines.
In these studies, gaseous fuel is regarded as a secondary fuel and diesel fuel is regarded as the main fuel for combustion. The objectives of these studies typically involve reducing particulate matter (PM) emissions by using gaseous fuel as a partial substitution for diesel fuel. However, the addition of gaseous fuel raises the combustion temperature, which increases emissions of nitrogen oxides (NOx). In the second category are studies focused on reactivity-controlled compression–ignition (RCCI) combustion. RCCI combustion can be implemented by early diesel injection with a large amount of low-reactivity fuel such as gasoline or gaseous fuel. Although RCCI combustion promises lower NOx and PM emissions and higher thermal efficiency than conventional diesel combustion, it requires a higher intake pressure (usually more than 1.7 bars) to maintain a lean fuel mixture. Therefore, in this study, practical applications of dual-fuel combustion with a low air–fuel ratio (AFR),which implies a low intake pressure, were systemically evaluated using propane in a diesel engine. The characteristics of dualfuel combustion for high and low AFRs were first evaluated. The proportion of propane used for four different operating conditions was then increased to decrease emissions and to identify the optimal condition for dual-fuel combustion. Although the four operating conditions differ, the AFR was maintained at 20 (Φ approximately equal to 0.72) and the 50% mass fraction burned (MFB 50) was also fixed. The results show that dual-fuel combustion can reduce NOx and PM emissions in comparison to conventional diesel combustion.

참고문헌 (Reference)

1 박세익, "디젤 예혼합 압축착화 엔진에서 배기가스 재순환과 과급의 영향" 한국자동차공학회 14 (14): 58-64, 2006

2 Ladommatos, N., "The dilution, chemical, and thermal effects of exhaust gas recirculation on diesel engine emissions -Part 4: Effects of carbon dioxide and water vapor" SAE 1997

3 Shi, Y., "Optimization of a heavy-duty compression-ignition engine fueled with diesel and gasoline-like fuels" 89 : 3416-3430, 2010

4 Kimura, S., "New combustion concept for ultraclean and high-efficiency small DI diesel engines" SAE 1999

5 Akihama, K., "Mechanism of the smokeless rich diesel combustion by reducing temperature" SAE 2001

6 Curran, S., "In-cylinder fuel blending of gasoline/diesel for improved efficiency and lowest possible emissions on a multi-cylinder lightduty diesel engine" SAE 2010

7 Kim, D. S., "In-cylinder CO and UHC imaging in a light-duty diesel engine during PPCI low-temperature combustion" SAE 2008

8 Splitter, D., "High efficiency, low emissions RCCI combustion by use of a fuel additive" SAE 2010

9 Nieman, D. E., "Heavy-duty RCCI operation using natural gas and diesel" SAE 2012

10 Kumar, R., "Heat release based adaptive control to improve low temperature diesel engine combustion" SAE 2007

11 Hasegawa, R., "HCCI combustion in DI diesel engine" SAE 2003

12 Hanson, R., "Fuel effects on reactivity controlled compression ignition (RCCI) combustion at low load" SAE 2011

13 Kim, H. J., "Experimental Researches for the Emission Reduction by Propane Addition on Dual Fuel Diesel Engine" Mechanical and Aerospace Engineering of Seoul National University 2012

14 Papagiannakis, R. G., "Emission characteristics of high speed, dual fuel, compression ignition engine operating in a wide range of natural gas/diesel fuel properties" 89 : 1397-1406, 2010

15 Saleh, H. E., "Effect of variation in LPG composition on emissions and performance in a dual fuel diesel engine" 87 : 3031-3039, 2008

16 Koci, C. P., "Detailed unburned hydrocarbon investigations in a highly-dilute diesel low temperature combustion regime" SAE 2009

17 Kokjohn, S., "Characterization of dualfuel PCCI combustion in a light-duty engine" 2010

18 Kamran Poorghasemi, "An investigation on effect of high pressure post injection on soot and NO emissions in a DI diesel engine" 대한기계학회 26 (26): 269-281, 2012

19 Liu Yu, "An experimental study on the effects of impingement-walls on the spray and combustion characteristics of SIDI CNG" 대한기계학회 26 (26): 2239-2246, 2012

20 Liu, C., "An experimental and numerical investigation of the combustion characteristics of a dual fuel engine with a swirl chamber" SAE 2007

21 Spindt, R. S., "Air-fuel ratios from exhaust gas analysis" SAE 1965