Browse Publications Technical Papers 2001-01-3634
2001-09-24

Effects of Fuel Injection Characteristics on Heat Release and Emissions in a DI Diesel Engine Operated on DME 2001-01-3634

In this study, an experimental investigation was conducted using a direct injection single-cylinder diesel engine equipped with a test common rail fuel injection system to clarify how dimethyl ether (DME) injection characteristics affect the heat release and exhaust emissions.
For that purpose the common rail fuel injection system (injection pressure: 15 MPa) and injection nozzle (0.55 × 5-holes, 0.70 × 3-holes, same total holes area) have been used for the test. First, to characterize the effect of DME physical properties on the macroscopic spray behavior: injection quantity, injection rate, penetration, cone angle, volume were measured using high-pressure injection chamber (pressure: 4MPa). In order to clarify effects of the injection process on HC, CO, and NOx emissions, as well as the rate of heat release were investigated by single-cylinder engine test. The effects of the injection rate and swirl ratio on exhaust emissions and heat release were also investigated.
Those two parts of the study (injection test and single-cylinder engine test) showed that the 5-hole injection nozzle has faster atomization and quicker vaporization around the spray core. It promotes premixed combustion but results in greater HC and CO emissions when a large quantity of fuel is injected. With the 3-hole injection nozzle, at the beginning of the spray development, showed a little longer spray penetration, wider spray angle and bigger spray volume than that of the 5-hole nozzle. It takes time to form the fuel atomization, which inhibits premixed combustion and results in an increase of unburned components at small quantity of fuel injection.
With the 3-hole injection nozzle, a higher injection rate results in a longer ignition delay, allowing spray to be distributed in a combustion chamber more extensively. A higher injection rate shows shorter combustion duration and improved cycle efficiency. When a large quantity of fuel is injected, an increase in swirl ratio enhances spray distribution and air-fuel mixture, therefore contributing to the reduction of HC and CO emissions with the 5-hole injection nozzle in particular. Due to the difference in injection and combustion process of the nozzles, at a large quantity of fuel injection, the 3-hole injection nozzle with an equivalent energy consumption rate of the 5-hole injection nozzle results in less NOx emissions.

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.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Durable Coating Technology for Lunar Dust Protection and Mitigation

2006-01-2205

View Details

TECHNICAL PAPER

Experiments and Multi-Dimensional Simulation of Dual-Fuel Diesel/Natural Gas Engines

2007-24-0124

View Details

TECHNICAL PAPER

Approaches to Solve Problems of the Premixed Lean Diesel Combustion

1999-01-0183

View Details

X