Browse Publications Technical Papers 2014-32-0108
2014-11-11

A Potentiality of Dedicated EGR in SI Engines Fueled by Natural Gas for Improving Thermal Efficiency and Reducing NO x Emission 2014-32-0108

Recently, a potentiality of Dedicated EGR (D-EGR) concept SI engine has been studied. This concept engine had four cylinders and operated with exhaust gas supplied from the single cylinder to the intake manifold. Compared with conventional SI engines, it was able to increase thermal efficiency and decrease CO, HC, and NOx emission by the high D-EGR ratio 0.25.
In this study, numerical analysis of a SI engine with D-EGR system with various D-EGR ratios was conducted for detailed understanding the potentiality of this concept in terms of thermal efficiency and NOx emission. #1 cylinder of assumed engine was used as D-EGR cylinder that equivalence ratio varied from 0.6 to 3.4. Entire exhaust gas from #1 cylinder was recirculated to the other cylinders. The other cylinders run with this exhaust gas and new premixed air and fuel with various equivalence ratios from 0.6-1.0. To study the effect of D-EGR ratio, the number of engine cylinders was considered from 3 to 6, same meaning with D-EGR ratio 0.5-0.2. A Laminar burning velocity and a flame temperature were considered to analyze thermal efficiency and NOx emission.
The results show that D-EGR system is able to make a similar level of thermal efficiency to that of conventional SI engines. NOx emission were reduced by decreasing flame temperature while the laminar burning velocity was increased without flame temperature rising due to the influence of H2 and CO that were included in EGR gas as intermediates.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
We also recommend:
TECHNICAL PAPER

CNG / Methane-Combustion Kinetics (without N2) and Frozen Equilibrium in Radical-Ignition Reduced Compression Ratio D.I. Diesel Engines Using Pistons with Micro-Chambers

2004-01-1677

View Details

TECHNICAL PAPER

Resolving EGR Distribution and Mixing

2002-01-2882

View Details

TECHNICAL PAPER

Conversion of a Diesel Engine for Gaseous Fuel Operation at High Compression Ratio

910849

View Details

X