An experimental investigation was performed on the effect of injection strategy on the combustion, exhaust emission characteristics and the particle size distribution in a small direct-injection (DI) compression ignition engine fueled with a biodiesel-ethanol blended fuel. The results obtained from the experiment of the particle distributions for the blended fuel are compared with that of diesel fuel. In addition to the distribution of the particles, exhaust emissions, such as oxides of nitrogen $(NOx)$, hydrocarbon (HC), and carbon monoxide (CO) emissions, and combustion characteristics under different injection parameters were investigated. The injection parameters in terms of first injection mass and second injection mass were varied to investigate the combustion and emission reduction in the biodiesel and ethanol blended fuel. The results show that the first combustion and heat release generated from the first injection, and then the second injected fuel rapidly combusted with an extremely short ignition delay. The maximum combustion pressures and heat releases of a biodiesel-ethanol blend are generally higher than those of the ultra-low sulfur diesel (ULSD) in all cases, regardless if an equal quantity of fuel is injected. The soot and $NOx$ emissions for a blend are relatively lower than the ULSD at all test ranges. In addition, HC and CO emissions for a blend also indicated relatively low levels compared with those of the ULSD. Double injection cases for biodiesel-ethanol blend, the number concentrations of larger size particles which are closely related to the weight of smoke emissions mass were significantly reduced.

1.
McCormic
,
R. L.
,
Tennant
,
C. J.
,
Hayes
,
R. R.
,
Black
,
S.
, and
Sharp
,
C.
, 2005, “
Regulated Emissions From Biodiesel Tested in Heavy Duty Engines Meeting 2004 Emission Standards
,” SAE Paper No. 2005-01-2200.
2.
Lee
,
C. S.
,
Park
,
S. W.
, and
Kwon
,
S. I.
, 2005, “
An Experimental Study on the Atomization and Combustion Characteristics of Biodiesel-Blended Fuels
,”
Energy Fuels
0887-0624,
19
, pp.
2201
2208
.
3.
Sharp
,
C. A.
,
Howell
,
S. A.
, and
Jobe
,
J.
, 2000, “
The Effect of Biodiesel Fuels on Transient Emissions From Modern Diesel Engine-Part I: Regulated Emissions and Performance
,” SAE Paper No. 2000-01-1967.
4.
Park
,
S. H.
,
Yoon
,
S. H.
,
Suh
,
H. K.
, and
Lee
,
C. S.
, 2008, “
Effect of the Temperature Variation on Properties of Biodiesel and Biodiesel-Ethanol Blends Fuels
,”
Oil Gas Sci. Technol.
,
63
(
6
), pp.
737
745
.
5.
Choi
,
Y.
, and
Reitz
,
R. D.
, 1999, “
An Experimental Study on the Effect of Oxygenated Fuel Blends and Multiple Injection Strategies on DI Diesel Engine Emissions
,”
Fuel
0016-2361,
78
, pp.
1303
1317
.
6.
Suh
,
H. K.
,
Roh
,
H. G.
, and
Lee
,
C. S.
, 2008, “
Spray and Combustion Characteristics of Biodiesel/Diesel Blended Fuel in a Direct Injection Common-Rail Diesel Engine
,”
ASME J. Eng. Gas Turbines Power
0742-4795,
130
, p.
032807
.