Effect of direct injection dimethyl ether on the micro-flame ignited (MFI) hybrid combustion and emission characteristics of a 4-stroke gasoline engine

Fu, Xue-Qing; He, Bang-Quan; Li, Hongtao; Chen, Tao; Xu, Si-Peng; Zhao, Hua

doi:10.1016/j.fuproc.2017.08.001

Cited by 16 publications

(12 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mechanism is based on five components (C 6 H 5 CH 3 , iC 5 H 12 , iC 8 H 18 , nC 5 H 12 , nC 7 H 16 ) gasoline surrogate mechanism, which comes from Lawrence Livermore National Laboratory (LLNL) [21]. This 207-species skeletal mechanism is validated under a wide range of conditions compared to the rapid compression machine (RCM) experimental data, and it has also been mentioned or verified widely in other research [22][23][24]. The mixture oil in this mechanism has similar properties to local oil products in Changchun, China, so the mechanism is suitable for this study and for future research.…”

Section: Experimental Methodsmentioning

confidence: 87%

Numerical Studies on the Action Mechanism of Combustion Intermediates and Free Radicals on Nitrogen Oxides under Oil-Water Blended Conditions

et al. 2018

Applied Sciences

View full text Add to dashboard Cite

The action mechanism of combustion intermediates and free radicals on nitrogen oxides have been evaluated. Based on chemical reaction dynamics and modern statistical theory, the subject was investigated by means of numerical simulation. A wide water/oil ratio and a wide air/fuel ratio were also taken into account. Some main conclusions were drawn that the reaction response of H 2 O 2 is lagged behind, with the increase of water mass fraction from 10% to 30%. The maximum generation rate is 2.77%, 5.67%, 8.38% and the maximum consumption rate is 3.55%, 6.80%, 13.01% lower than that without water. Water addition leads to decline of the maximum generation rate of NO, N 2 O, NO 2 by 15.24%, 9.21%, 14.78% on average. Further, the saliency factor is explored in the main reaction process depending on the correlation analysis and the sensitivity analysis method. According to the degree of the significance, OH > O > H 2 for NO, O > H 2 > OH > HO 2 for N 2 O, and OH > H 2 > O > H 2 O 2 > HO 2 for NO 2. In the case of oil-water blended, H + O 2 <=> O + OH and H 2 O 2 (+M) <=> 2OH(+M) promote the generation of OH and O at the beginning of the second stage, but H + O 2 (+M) <=> HO 2 (+M), HO 2 + OH <=> H 2 O + O 2 , H 2 O 2 + OH <=> H 2 O + HO 2 play an inhibitory role in the generation of OH and O.

show abstract

Section: Experimental Methodsmentioning

confidence: 87%

Numerical Studies on the Action Mechanism of Combustion Intermediates and Free Radicals on Nitrogen Oxides under Oil-Water Blended Conditions

et al. 2018

Applied Sciences

View full text Add to dashboard Cite

show abstract

“…The DME was pressurized by gaseous N 2 in a pressure vessel and supplied to the DI injector at the pressure of 40 bar, and the complete DME fueling system was designed and checked to avoid the formation of bubbles in the fuel lines. 22 The properties of gasoline and DME are shown in Table 2.…”

Section: Experimental Setup and Proceduresmentioning

confidence: 99%

“…20 Besides, its lack of C–C bonds and high oxygen content can achieve soot-free combustion due to low formation and high oxidation rates. 21 When injected into the premixed high octane fuel and air mixture, DME can ideally provide multiple auto-ignition sites to control and accelerate the ignition and shorten main combustion processes in a lean-burn mixture, which leads to the research and development of multi-point micro-flame-ignited (MFI) hybrid combustion, 22,23 in which multi-point flames are formed by auto-ignition of directly injected DME, and its released heat induces the auto-ignition of unburned premixed gasoline mixture. As reported earlier, direct injection (DI) of DME can enhance flame propagation in the early stage of combustion 24 and directly trigger auto-ignition of premixed gasoline mixture with hot burned gases through exhaust throttling, 25 or intake re-breathing by pilot intake valve open during the exhaust stroke.…”

Section: Introductionmentioning

confidence: 99%

“…Effects of single and split DI of DME on the MFI combustion were experimentally investigated at part loads when the first injection timing of DME is kept at −220 °CA ATDC and the second injection timing of DME is changed in the range from −60 °CA to −40 °CA ATDC at an excess air coefficient (Lambda) of 1.6. 22,23 Although the thermal efficiency of the gasoline engine in MFI combustion is higher than that in SI combustion, the raw NOx emissions in MFI combustion are generally in the range from 300 to 400 ppm. 22,23…”

Section: Introductionmentioning

confidence: 99%

“…22,23 Although the thermal efficiency of the gasoline engine in MFI combustion is higher than that in SI combustion, the raw NOx emissions in MFI combustion are generally in the range from 300 to 400 ppm. 22,23…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Multi-point micro-flame ignited hybrid lean-burn combustion of gasoline with direct injection dimethyl ether

et al. 2019

International Journal of Engine Research

Self Cite

View full text Add to dashboard Cite

Lean-burn combustion is effective in reducing fuel consumption of gasoline engines because of the higher specific heat ratio of the fuel lean mixture and reduced heat loss from lower combustion temperature. However, its application to real engines is hampered by the unstable ignition, high cyclic variability, and partial-burn due to slower combustion, as well as the restricted maximum lean-burn air/fuel ratio limit and the insufficiently low nitrogen oxides emission. Multi-point micro-flame-ignited hybrid combustion has been proposed and applied to extend the lean burn limit of premixed gasoline and air mixture. To achieve micro-flame-ignited combustion in premixed lean gasoline mixture formed by port fuel injection, a small amount of dimethyl ether is injected directly into the cylinder of a four-stroke gasoline engine to control and accelerate the ignition and combustion process so that the engine could be operated with the overall excess air coefficient (Lambda) of 1.9. The results show that heat release processes can be grouped into three forms, that is, ramp type, double-peak type, and trapezoid type. Regardless of single or split injections, direct injection timing of dimethyl ether dominates the features of heat release. The ramp type occurs at early injection timing while the double-peak type takes place at late injection timing. Trapezoid type appears between the above two types. Dimethyl ether injection timing controls the ignition timing and has less effect on combustion duration. Single injection of dimethyl ether leads to much earlier ignition timing and slightly longer combustion duration, forming higher nitrogen oxides emissions than the split injections. Ultra-low nitrogen oxides emissions and higher thermal efficiency are achieved in the ramp type combustion compared to the other two types of combustion in both injection approaches.

show abstract

Effects of second injection timing on combustion characteristics of the spark ignition direct injection gasoline engines with dimethyl ether enrichment in the intake port

Shi

Wang

et al. 2019

Energy

View full text Add to dashboard Cite

Effect of direct injection dimethyl ether on the micro-flame ignited (MFI) hybrid combustion and emission characteristics of a 4-stroke gasoline engine

Cited by 16 publications

References 27 publications

Numerical Studies on the Action Mechanism of Combustion Intermediates and Free Radicals on Nitrogen Oxides under Oil-Water Blended Conditions

Numerical Studies on the Action Mechanism of Combustion Intermediates and Free Radicals on Nitrogen Oxides under Oil-Water Blended Conditions

Multi-point micro-flame ignited hybrid lean-burn combustion of gasoline with direct injection dimethyl ether

Effects of second injection timing on combustion characteristics of the spark ignition direct injection gasoline engines with dimethyl ether enrichment in the intake port

Contact Info

Product

Resources

About