Engine experiments were carried out to study the impact of multiple pilot injections of a diesel fuel on dual-fuel combustion with a premixed ethanol fuel, using compression ignition. Because of the contrasting volatility and the reactivity characteristics of the two fuels, the appropropriate scheduling of pilot diesel injections in a high-pressure direct-injection process is found to be effective for improving the clean and efficient combustion of ethanol which is premixed with air using a low-pressure port injection. The timing and duration of each of the multiple pilot injections were investigated, in conjunction with the use of exhaust gas recirculation and intake air boosting to accommodate the variations in the engine load. For correct fuel and air management, an early pilot injection of fuel acted effectively as the reactivity improver to the background ethanol, whereas a late pilot injection acted deterministically to initiate combustion. The experimental results further revealed a set of pilot injection strategies which resulted in an increased ethanol ratio, thereby reducing the emission reductions while retaining a moderate pressure rise rate during combustion.
JhavarRRutlandC. Effects of mixing on early injection diesel combustion. SAE paper 2005-01-0154, 2005.
2.
BenajesJMolinaSNovellaRBelarteE. Evaluation of massive exhaust gas recirculation and Miller cycle strategies for mixing-controlled low temperature combustion in a heavy duty diesel engine. Energy2014; 71: 355–366.
3.
KurtzEMFosterDE. Identifying a critical time for mixing in a direct injection diesel engine through the study of increased in-cylinder mixing and its effect on emissions. Int J Engine Res2004; 5(3): 247–256.
4.
HanXZhengMWangJ. Fuel suitability for low temperature combustion in compression ignition engines. Fuel2013; 109: 336–349.
5.
DimitriouPPengZWangWet al. Effects of advanced injection strategies on the in-cylinder air–fuel homogeneity of diesel engines. Proce IMechE Part D: J Automobile Engineering2015; 229(3): 330–341.
6.
ThringR. Homogeneous-charge compression-ignition (HCCI) engines. SAE paper 892068, 1989.
7.
SplitterDReitzRHansonR. High efficiency, low emissions RCCI combustion by use of a fuel additive. SAE paper 2010-01-2167, 2010.
8.
ReitzRDuraisamyG. Review of high efficiency and clean reactivity controlled compression ignition (RCCI) combustion in internal combustion engines. Prog Energy Combust Sci2015; 46: 12–71.
9.
SuHMosbachSKraftMet al. Two-stage fuel direct injection in a diesel fuelled HCCI engine. SAE paper 2007-01-1880, 2007.
10.
de OjedaWZoldakPEspinosaRKumarR. Development of a fuel injection strategy for diesel LTC. SAE paper 2008-01-0057, 2008.
11.
HelmantelADenbrattI. HCCI operation of a passenger car common rail DI diesel engine with early injection of conventional diesel fuel. SAE paper 2004-01-0935, 2004.
12.
ZhengMKumarR. Implementation of multiple-pulse injection strategies to enhance the homogeneity for simultaneous low-NOx and -soot diesel combustion. Int J Thermal Sci2009; 48: 1829–1841.
13.
LujanMGuardiolaCPlaBReigA. Switching strategy between HP (high pressure)- and LPEGR (low pressure exhaust gas recirculation) systems for reduced fuel consumption and emissions. Energy2015; 90: 1790–1798.
14.
JungYParkSBaeC. Effect of oxygen concentration on highly diluted charge compression ignition combustion in an optical engine. Appl Thermal Engng2015; 90: 538–550.
15.
ZhengMReaderGHawleyG. Diesel engine exhaust gas recirculation – a review on advanced and novel concepts. Energy Conversion Managmt2004; 45: 883–900.
16.
ChoKHanMWagnerRSluderC. Mixed-source EGR for enabling high efficiency clean combustion modes in a light-duty diesel engine. SAE paper 2008-01-0645, 2008.
17.
KhalefMSobaAKorsgrenJ. Study of EGR and turbocharger combinations and their influence on diesel engine’s efficiency and emissions. SAE paper 2016-01-0676, 2016.
18.
DivekarPChenXTjongJZhengM. Energy efficiency impact of EGR on organizing clean combustion in diesel engines. Energy Conversion Managmt2016; 112: 369–381.
19.
LuXHanDHuangZ. Fuel design and management for the control of advanced compression-ignition combustion modes. Prog Energy Combust Sci2011; 37: 741–783.
AsadUKumarRZhengMTjongJ. Ethanol-fueled low temperature combustion: a pathway to clean and efficient diesel engine cycles. Appl Energy2015; 157: 838–850.
22.
VibhanshuVKumarNMishraCet al. Experimental investigation of diesel engine fueled with jatropha oil blend with ethanol. SAE paper 2013-24-0105, 2013.
23.
GaoTDivekarPAsadUet al. An enabling study of low temperature combustion with ethanol in a diesel engine. J Energy Resour Technol2013; 135: 042203-1–042203-8.
24.
ZhangFZeraati RezaeiSXuHShuaiS. Experimental investigation of different blends of diesel and gasoline (dieseline) in a CI engine. SAE paper 2014-01-2686, 2014.
25.
SolakaHAronssonUTunerMJohanssonB. Investigation of partially premixed combustion characteristics in low load range with regards to fuel octane number in a light-duty diesel engine. SAE paper 2012-01-0684, 2012.
26.
KokjohnSHansonRSplitterDReitzR. Experiments and modeling of dual-fuel HCCI and PCCI combustion using in-cylinder fuel blending. SAE paper 2009-01-2647, 2009.
27.
JungSIshidaMYamamotoHet al. Enhancement of NOx–PM trade-off in a diesel engine adopting bio-ethanol and EGR. Int J Automot Technol2010; 11(5): 611–616.
28.
GaoTJefticMBrydenGet al. Heat release analysis of clean combustion with ethanol ignited by diesel in a high compression ratio engine. SAE paper 2016-01-0766, 2016.
29.
PedrozoVMayINoraMet al. Experimental analysis of ethanol dual-fuel combustion in a heavy-duty diesel engine: an optimisation at low load. Appl Energy2016; 165: 166–182.
30.
HanXTjongJWangMet al. Renewable ethanol use for enabling high load clean combustion in a diesel engine. SAE paper 2013-01-0904, 2013.
31.
ZhengMTanYReaderGet al. Prompt heat release analysis to improve diesel low temperature combustion. SAE paper 2009-01-1883, 2009.
32.
OgawaHShibataGKatoTZhaoP. Dual fuel diesel combustion with premixed ethanol as the main fuel. SAE paper 2014-01-2687, 2014.
33.
ManenteVJohanssonBTunestalP. Partially premixed combustion at high load using gasoline and ethanol, a comparison with diesel. SAE paper 2009-01-0944, 2009.
