Homogeneous charge compression iginition (HCCI) combustion allows for the use of fuels with octane requirements below that of spark-ignited engines. A reference gasoline was compared with iso-octane and a low octane blend of gasoline and 40% n-heptane, NH40. Experiments were conducted on a single cylinder engine operating with negative valve overlap (NVO). The fuel flow rate per cycle was compensated based on the lower heating value to maintain a constant energy addition across fuels. Iso-octane and gasoline demonstrated similar maximum load, achieving a gross IMEPg of ~430 kPa, whereas the NH40 demonstrated an increased IMEPg of ~460 kPa. The NH40 could be operated at a later phasing compared with the higher octane fuels, and exhibited a shorter burn duration at a given fueling rate and phasing. These results could be due to compositional differences, as NH40 required less NVO compared to iso-octane and gasoline, leading to less thermal and compositional stratification, as well as a higher O2 concentration and less residual gas. Additionally, the NH40 fuel demonstrated a higher intermediate temperature heat release than the higher octane fuels, potentially contributing to the shorter burn duration. Overall, these results demonstrate clear benefits to NVO enabled HCCI combustion with low octane fuels.

References

1.
Onishi
,
S.
,
Jo
,
H. S.
,
Shoda
,
K.
,
Jo
,
P. D.
, and
Kato
,
S.
,
1979
, “
Active Thermo-Atmoshphere Combustion (ATAC)—A New Combustion Processs for Internal Combustion Engines
,”
SAE
Technical Paper No. 790501.10.4271/790501
2.
Najt
,
P. M.
, and
Foster
,
D. E.
,
1983
, “
Compression-Ignited Homogeneous Charge Combustion
,”
SAE
Paper No. 830264.10.4271/830264
3.
Hildingsson
,
L.
,
Kalghatgi
,
G.
,
Tait
,
N.
,
Johansson
,
B.
, and
Harrison
,
A.
,
2009
, “
Fuel Octane Effects in the Partially Premixed Combustion Regime in Compression Ignition Engines
,”
SAE
Paper No. 2009-01-2648.10.4271/2009-01-2648
4.
Shibata
,
G.
, and
Urushihara
,
T.
,
2008
, “
Dual Phase High Temperature Heat Release Combustion
,”
SAE
Paper No. 2008-01-0007.10.4271/2008-01-0007
5.
Shibata
,
G.
, and
Urushihara
,
T.
,
2009
, “
Realization of Dual Phase High Temperature Heat Release Combustion of Base Gasoline Blends From Oil Refineries and a Study of HCCI Combustion Processes
,”
SAE
Paper No. 2009-01-0298.10.4271/2009-01-0298
6.
Yang
,
Y.
,
Dec
,
J.
,
Dronniou
,
N.
,
Sjöberg
,
M.
, and
Cannella
,
W.
,
2011
, “
Partial Fuel Stratification to Control HCCI Heat Release Rates: Fuel Composition and Other Factors Affecting Pre-Ignition Reactions of Two-Stage Ignition Fuels
,”
SAE
Paper No. 2011-01-1359.10.4271/2011-01-1359
7.
Yang
,
Y.
,
Dec
,
J.
, and
Dronniou
,
N.
,
2012
, “
Boosted HCCI Combustion Using Low-Octane Gasoline With Fully Premixed and Partially Stratified Charges
,”
SAE
Paper No. 2012-01-1120.10.4271/2012-01-1120
8.
Dec
,
J. E.
, and
Yang
,
Y.
,
2010
, “
Boosted HCCI for High Power Without Engine Knock and With Ultra-Low NOx Emissions—Using Conventional Gasoline
,”
SAE
Paper No. 2010-01-1086.10.4271/2010-01-1086
9.
Manofsky
,
L.
,
Vavra
,
J.
, and
Babajimopoulos
,
A.
,
2011
, “
Bridging the Gap Between HCCI and SI: Spark-Assisted Compression Ignition
,”
SAE
Paper No. 2011-01-1179.10.4271/2011-01-1179
10.
Olsson
,
J.
,
Tunestå
,
L. P.
,
Ulfvik
,
J.
, and
Johansson
,
B.
,
2003
, “
The Effect of Cooled EGR on Emissions and Performance of a Turbocharged HCCI Engine
,”
SAE
Paper No. 2003-01-0743.10.4271/2003-01-0743
11.
Babajimopoulos
,
A.
,
Challa
, V
.
,
Lavoie
,
G.
, and
Assanis
,
D.
,
2009
, “
Model-Based Assessment of Two Variable CAM Timing Strategies for HCCI Engines: Recompression vs. Rebreathing
,”
Proceedings of the ASME Internal Combustion Engine Division 2009 Spring Technical Conference
, Milwaukee, WI, May 3–6,
ASME
Paper No. ICES2009-76103.10.1115/ICES2009-76103
12.
Eng
,
J.
,
2002
, “
Characterization of Pressure Waves in HCCI Combustion
,”
SAE
Paper No. 2002-01-2859.10.4271/2002-01-2859
13.
Chang
,
J.
,
Güralp
,
O.
,
Filipi
,
Z.
,
Assanis
,
D.
,
Kuo
,
T.-W.
,
Najt
,
P.
, and
Rask
,
R.
,
2004
, “
New Heat Transfer Correlation for an HCCI Engine Derived From Measurments of Instantaneous Surface Heat Flux
,”
SAE
Paper No. 2004-01-2996.10.4271/2004-01-2996
14.
Woschni
,
G.
,
1967
, “
A Universally Applicable Equation for the Instantaneous Heat Transfer Coefficient in the Internal Combustion Engine
,”
SAE
Paper No. 67093
1
.
10.4271/670931
15.
Ortiz-Soto
,
E. A.
,
Vavra
,
J.
, and
Babajimopoulos
,
A.
,
2011
, “
Assessment of Residual Mass Estimation Methods for Cylinder Pressure Heat Release Analysis of HCCI Engines With Negative Valve Overlap
,”
Proceedings of the ASME 2011 Internal Combustion Engine Division Fall Technical Conference
, Morgantown, WV, October 2–5,
ASME
Paper No. ICES2011-60167.10.1115/ICEF2011-60167
16.
Lavoie
,
G. A.
,
Martz
,
J.
,
Wooldridge
,
M.
, and
Assanis
,
D.
,
2010
, “
A Multi-Mode Combustion Diagram for Spark Assisted Compression Ignition
,”
Combust. Flame
,
157
(
6
), pp.
1106
1110
.10.1016/j.combustflame.2010.02.009
17.
Sjöberg
,
M.
, and
Dec
,
J. E.
,
2005
, “
An Investigation Into Lowest Acceptable Combustion Temperatures for Hydrocarbon Fuels in HCCI Engines
,”
Proc. Combust. Inst.
,
30
(
2
), pp.
2719
2726
.10.1016/j.proci.2004.08.132
18.
Manofsky-Olesky
,
L.
,
Vavra
,
J.
,
Babajimopoulos
,
A.
, and
Assanis
,
D.
,
2012
, “
Internal Residual vs. Elevated Intake Temperature: How the Method of Charge Preheating Affects the Phasing Limitations of HCCI Combustion
,”
Proceedings of the ASME 2012 Internal Combustion Engine Division Spring Technical Conference
, Torino, Italy, May 6–9, Paper No. ICES2012-81127.
19.
He
,
X.
,
Donovan
,
M.
,
Zigler
,
B.
,
Palmer
,
T.
,
Walton
,
S.
,
Wooldridge
,
M.
, and
Atreya
,
A.
,
2005
, “
An Experimental and Modeling Study of Iso-Octane Ignition Delay Times Under Homogeneous Charge Compression Ignition Conditions
,”
Combust. Flame
,
142
(
3
), pp.
266
275
.10.1016/j.combustflame.2005.02.014
20.
Martz
,
J. B.
,
2010
, “
Simulation and Model Development for Auto-Ignition and Reaction Front Propagation in Low Temperature High-Pressure Lean-Burn Engines
,”
Ph.D.
thesis,
University of Michigan, Ann Arbor, MI
.
21.
Rothamer
,
D. A.
,
Snyder
,
J. A.
,
Hanson
,
R. K.
,
Steeper
,
R. R.
, and
Fitzgerald
,
R. P.
,
2009
, “
Simultaneous Imaging of Exhaust Gas Residuals and Temperature During HCCI Combustion
,”
Proc. Combust. Inst.
,
32
(
2
), pp.
2869
2876
.10.1016/j.proci.2008.07.018
22.
Sjöberg
,
M.
, and
Dec
,
J. E.
,
2004
, “
Comparing Enhanced Natural Thermal Stratification Against Retarded Combustion Phasing for Smoothing of HCCI Heat-Release Rates
,”
SAE
Paper No. 2004-01-2994.10.4271/2004-01-2994
23.
Hwang
,
W.
,
Dec
,
J.
, and
Sjoberg
,
M.
,
2008
, “
Spectroscopic and Chemical-Kinetic Analysis of the Phases of HCCI Autoignition and Combustion for Single- and Two-Stage Ignition Fuels
,”
Combust. Flame
,
154
(
3
), pp.
387
409
.10.1016/j.combustflame.2008.03.019
24.
Sjöberg
,
M.
, and
Dec
,
J. E.
,
2003
, “
Combined Effects of Fuel-Type and Engine Speed on Intake Temperature Requirements and Completeness of Bulk-Gas Reactions for HCCI Combustion
,”
SAE
Paper No. 2003-01-3173.10.4271/2003-01-3173
25.
Sjöberg
,
M.
, and
Dec
,
J. E.
,
2007
. “
EGR and Intake Boost for Managing HCCI Low-Temperature Heat Release Over Wide Ranges of Engine Speed
,”
SAE
Paper No. 2007-01-0051.10.4271/2007-01-0051
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