Today, we are faced with the problems of global warming and fossil fuel depletion, and they have led to the enforcement of new emissions regulations. Direct-injection spark-ignition engines are a very promising technology that can comply with the new regulations. These engines offer the advantages of better fuel economy and lower emissions than conventional port-injection engines. The use of liquefied petroleum gas (LPG) as the fuel reduces carbon emissions because of its vaporization characteristics and the fact that it has lower carbon content than gasoline. An experimental study was carried out to investigate the combustion process and emission characteristics of a 2 l spray-guided LPG direct-injection engine under lean operating conditions. The engine was operated at a constant speed of 2000 rpm under 0.2 MPa brake mean effective pressure (BMEP), which corresponds to a common operation point of a passenger vehicle. Combustion stability, which is the most important component of engine performance, is closely related to the operation strategy and it significantly influences the degree of fuel consumption reduction. In order to achieve stable combustion with a stratified LPG mixture, an interinjection spark ignition (ISI) strategy, which is an alternative control strategy to two-stage injection, was employed. The effects of the compression ratio on fuel economy were also assessed; due to the characteristics of the stratified LPG mixture, the fuel consumption did not reduce when the compression ratio was increased.

References

References
1.
United Nations Environment Programme
,
2009
, “
Moving Towards a Climate Neutral UN the UN System's Footprint and Efforts to Reduce It
,” Nairobi, Kenya, DTI/1516/GE.
2.
Harada
,
J.
,
Tomita
,
T.
,
Mizuno
,
H.
,
Mashiki
,
Z.
, and
Ito
,
Y.
,
1997
, “
Development of Direct Injection Gasoline Engine
,”
SAE
Paper No. 970540.
3.
Iwamoto
,
Y.
,
Noma
,
K.
,
Nakayama
,
O.
,
Yamauchi
,
T.
, and
Ando
,
H.
,
1997
, “
Development of Gasoline Direct Injection Engine
,”
SAE
Paper No. 970541.
4.
Spicher
,
U.
,
Reissing
,
J.
,
Kech
,
J. M.
, and
Gindele
,
J.
,
1999
, “
Gasoline Direct Injection (GDI) Engines-Development Potentialities
,”
SAE
Paper No. 1999-01-2938.
5.
Zhao
,
F.
,
Lai
,
M.-C.
, and
Harrington
,
D.
,
1999
, “
Automotive Spark-Ignited Direct-Injection Gasoline Engines
,”
Prog. Energy Combust. Sci.
,
25
(
5
), pp.
437
562
.
6.
Alkidas
,
A. C.
, and
El Tahry
,
S. H.
,
2003
, “
Contributors to the Fuel Economy Advantage of DISI Engines Over PFI Engines
,”
SAE
Paper No. 2003-01-3101.
7.
van Basshuysen
,
R.
,
2009
,
Gasoline Engine With Direct Injection: Processes, Systems, Development, Potential
,
Vieweg + Teubner in GWV Fachverlage GmbH
,
Wiesbaden, Germany
.
8.
Zhao
,
F.-Q.
,
Lai
,
M.-C.
, and
Harrington
,
D. L.
,
1997
, “
A Review of Mixture Preparation and Combustion Control Strategies for Spark-Ignited Direct-Injection Gasoline Engines
,”
SAE
Paper No. 970627.
9.
Oh
,
S.
,
Kim
,
S.
,
Bae
,
C.
,
Kim
,
C.
, and
Kang
,
K.
,
2002
, “
Flame Propagation Characteristics in a Heavy Duty LPG Engine With Liquid Phase Port Injection
,”
SAE
Paper No. 2002-01-1736.
10.
Lee
,
E.
,
Park
,
J.
,
Huh
,
K. Y.
,
Choi
,
J.
, and
Bae
,
C.
,
2003
, “
Simulation of Fuel/Air Mixture Formation for Heavy Duty Liquid Phase LPG Injection (LPLI) Engines
,”
SAE
Paper No. 2003-01-0636.
11.
Kajiwara
,
M.
,
Sugiyama
,
K.
,
Sagara
,
M.
,
Mori
,
M.
,
Goto
,
S.
, and
Alam
,
M.
,
2002
, “
Performance and Emissions Characteristics of an LPG Direct Injection Diesel Engines
,”
SAE
Paper No. 2002-01-0869.
12.
Lee
,
S.
,
Kusaka
,
J.
, and
Daisho
,
Y.
,
2003
, “
Mixture Formation and Combustion Characteristics of Directly Injected LPG Spray
,”
SAE
Paper No. 2003-01-1917.
13.
Myung
,
C.-L.
,
Choi
,
K.
,
Kim
,
J.
,
Lim
,
Y.
,
Lee
,
J.
, and
Park
,
S.
,
2012
, “
Comparative Study of Regulated and Unregulated Toxic Emissions Characteristics From a Spark Ignition Direct Injection Light-Duty Vehicle Fueled With Gasoline and Liquid Phase LPG (Liquefied Petroleum Gas)
,”
Energy
,
44
(
1
), pp.
189
196
.
14.
Oh
,
S.
,
Lee
,
S.
,
Choi
,
Y.
,
Kang
,
K.-Y.
,
Cho
,
J.
, and
Cha
,
K.
,
2010
, “
Combustion and Emission Characteristics in a Direct Injection LPG/Gasoline Spark Ignition Engine
,”
SAE
Paper No. 2010-01-1461.
15.
Chang
,
W.-S.
,
Kim
,
Y.-N.
, and
Kong
,
J.-K.
,
2007
, “
Design and Development of a Spray-Guided Gasoline DI Engine
,”
SAE
Paper No. 2007-01-3531.
16.
Baecker
,
H.
,
Kaufmann
,
A.
, and
Tichy
,
M.
,
2007
, “
Experimental and Simulative Investigation on Stratification Potential of Spray-Guided GDI Combustion Systems
,”
SAE
Paper No. 2007-01-1407.
17.
Park
,
C.
,
Kim
,
S.
,
Kim
,
H.
, and
Moriyoshi
,
Y.
,
2012
, “
Stratified Lean Combustion Characteristics of a Spray-Guided Combustion System in a Gasoline Direct Injection Engine
,”
Energy
,
41
(
1
), pp.
401
407
.
18.
Szekely
,
G. A.
, and
Alkidas
,
A. C.
,
2005
, “
Combustion Characteristics of a Spray-Guided Direct-Injection Stratified-Charge Engine With a High-Squish Piston
,”
SAE
Paper No. 2005-01-1937.
19.
Park
,
C.
,
Park
,
Y.
,
Oh
,
S.
,
Lee
,
Y.
, and
Kim
,
T. Y.
,
2013
, “
Effect of Injection Timing Retard on ISI Strategy in Lean-Burning LPG Direct Injection Engines
,”
SAE
Paper No. 2013-01-2636.
20.
Park
,
C.
,
Park
,
Y.
,
Oh
,
S.
,
Lee
,
Y.
,
Kim
,
T. Y.
,
Kim
,
H.
,
Choi
,
Y.
, and
Kang
,
K.-Y.
,
2013
, “
Emission Characteristics of Gasoline and LPG in a Spray-Guided-Type Direct Injection Engine
,”
SAE
Paper No. 2013-01-1323.
21.
Costa
,
R. C.
, and
Sodré
,
J. R.
,
2011
, “
Compression Ratio Effects on an Ethanol/Gasoline Fuelled Engine Performance
,”
Appl. Therm. Eng.
,
31
(
2–3
), pp.
278
283
.
22.
Mehdi
,
S. N.
,
Reddy
,
D. N.
, and
Reddy
,
A. S.
,
2000
, “
Energy Conservation in Two-Stroke Spark Ignition Engines by Varying the Compression Ratio
,”
Energy Sustainable Dev.
,
4
(
2
), pp.
53
57
.
23.
Heywood
,
J. B.
,
1988
,
Internal Combustion Engine Fundamentals
,
McGraw-Hill
,
New York
.
24.
Stone
,
R.
,
2012
,
Introduction to Internal Combustion Engines
,
Palgrave Macmillan
,
Basingstoke, UK
.
25.
Park
,
C.
,
Lim
,
G.
,
Lee
,
S.
,
Kim
,
C.
, and
Choi
,
Y.
,
2013
, “
Effects of the Ignition Timing Retard and the Compression Ratio on the Full-Load Performance and the Emissions Characteristics of a Heavy-Duty Engine Fuelled by Hydrogen-Natural-Gas Blends
,”
Proc. Inst. Mech. Eng., Part J
,
227
(
9
), pp.
1295
1302
.
26.
Lim
,
G.
,
Lee
,
S.
,
Park
,
C.
,
Choi
,
Y.
, and
Kim
,
C.
,
2014
, “
Effect of Ignition Timing Retard Strategy on NOx Reduction in Hydrogen-Compressed Natural Gas Blend Engine With Increased Compression Ratio
,”
Int. J. Hydrogen Energy
,
39
(
5
), pp.
2399
2408
.
27.
Lim
,
G.
,
Lee
,
S.
,
Park
,
C.
,
Choi
,
Y.
, and
Kim
,
C.
,
2013
, “
Effects of Compression Ratio on Performance and Emission Characteristics of Heavy-Duty SI Engine Fuelled With HCNG
,”
Int. J. Hydrogen Energy
,
38
(
11
), pp.
4831
4838
.
28.
Park
,
C.
,
Kim
,
S.
,
Kim
,
H.
,
Lee
,
S.
,
Kim
,
C.
, and
Moriyoshi
,
Y.
,
2011
, “
Effect of a Split-Injection Strategy on the Performance of Stratified Lean Combustion for a Gasoline Direct-Injection Engine
,”
Proc. Inst. Mech. Eng., Part J
,
225
(
10
), pp.
1415
1426
.
29.
Piock
,
W. F.
,
Weyand
,
P.
,
Wolf
,
E.
, and
Heise
,
V.
,
2010
, “
Ignition Systems for Spray-Guided Stratified Combustion
,”
SAE
Paper No. 2010-01-0598.
30.
Yang
,
V.
,
2000
, “
Modeling of Supercritical Vaporization, Mixing, and Combustion Processes in Liquid-Fueled Propulsion Systems
,”
Proc. Combust. Inst.
,
28
(
1
), pp.
925
942
.
31.
Givler
,
S. D.
, and
Abraham
,
J.
,
1996
, “
Supercritical Droplet Vaporization and Combustion Studies
,”
Prog. Energy Combust. Sci.
,
22
(
1
), pp.
1
28
.
32.
Lacaze
,
G.
, and
Oefelein
,
J. C.
,
2012
, “
A Non-Premixed Combustion Model Based on Flame Structure Analysis at Supercritical Pressures
,”
Combust. Flame
,
159
(
6
), pp.
2087
2103
.
33.
Schwarz
,
C.
,
Schünemann
,
E.
,
Durst
,
B.
,
Fischer
,
J.
, and
Witt
,
A.
,
2006
, “
Potentials of the Spray-Guided BMW DI Combustion System
,”
SAE
Paper No. 2006-01-1265.
34.
Kim
,
S.-J.
,
Kim
,
Y.-N.
, and
Lee
,
J.-H.
,
2008
, “
Analysis of the In-Cylinder Flow, Mixture Formation and Combustion Processes in a Spray-Guided GDI Engine
,”
SAE
Paper No. 2008-01-0142.
35.
Husted
,
H. L.
,
Piock
,
W.
, and
Ramsay
,
G.
,
2009
, “
Fuel Efficiency Improvements From Lean, Stratified Combustion With a Solenoid Injector
,”
SAE
Paper No. 2009-01-1485.
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