The present study uses numerical simulations to explore the use of hydrated (wet) ethanol for reactivity controlled compression ignition (RCCI) operation in a heavy duty diesel engine. RCCI uses in-cylinder blending of a low reactivity fuel with a high reactivity fuel and has demonstrated significant fuel efficiency and emissions benefits using a variety of fuels, including gasoline and diesel. Combustion timing is controlled by the local blended fuel reactivity (i.e., octane number), and the combustion duration can be controlled by establishing optimized gradients in fuel reactivity in the combustion chamber. In the present study, the low reactivity fuel was hydrated ethanol while the higher reactivity fuel was diesel. First, the effect of water on ethanol/water/diesel mixtures in completely premixed HCCI combustion was investigated using GT-Power and single-zone CHEMKIN simulations. The results showed that the main impact of the water in the ethanol is to reduce the initial in-cylinder temperature due to vaporization cooling. Next, multi-dimensional engine modeling was performed using the KIVA code at engine loads from 5 to 17 bars IMEP at 1300 rev/min with various grades of hydrated ethanol and a fixed diesel fraction of the total fuel. The results show that hydrated ethanol can be used in RCCI combustion with gross indicated thermal efficiencies up to 55% and very low emissions. A 70/30 ethanol/water mixture (by mass) was found to yield the best results across the entire load range without the need for EGR.

References

References
1.
Pimentel
,
D.
, 2001, “
The Limits of Biomass Energy
,”
Encyclopedia of Physical Science and Technology
, Vol.
2
,
3rd ed.
,
Academic Press
,
New York
, pp.
159
171
.
2.
Shapouri
,
H.
,
Duffield
,
J. A.
, and
Wang
,
M.
, 2003, “
The Energy Balance of Corn Ethanol Revisited
,”
Trans. ASAE
,
46
(
4
), pp.
959
968
.
3.
Shapouri
,
H.
,
Duffield
,
J. A.
, and
Graboski
,
M. S.
, 1995, “
Estimating the Net Energy Balance of Corn Ethanol
,” USDA Economic Research Service.
4.
Flowers
,
D. L.
,
Aceves
,
S. M.
, and
Frias
,
J. M.
, 2007, “
Improving Ethanol Life Cycle Energy Efficiency by Direct Utilization of Wet Ethanol in HCCI Engines
,”
SAE
Paper No. 2007-01-1867.
5.
Najt
,
P. M.
, and
Foster
,
D. E.
, 1983, “
Compression-Ignited Homogeneous Charge Combustion
,”
SAE Paper No. 830264
.
6.
Tsurushima
,
T.
,
Kunishima
,
E.
,
Asaumi
,
Y.
, and
Aoyagi
,
Y.
, 2002, “
The Effect of Knock on Heat Loss in Homogeneous Charge Compression Ignition Engines
,”
SAE
Paper No. 2002-01-0108.
7.
Megaritis
,
A.
,
Yap
,
D.
, and
Wyszynski
,
M. L.
, 2007, “
Effect of Water Blending on Bioethanol HCCI Combustion With Forced Induction and Residual Gas Trapping
,”
Energy
,
32
, pp.
2396
2400
.
8.
Bessonette
,
P. W.
,
Schleyer
,
C. H.
,
Duffy
,
K. P.
,
Hardy
,
W. L.
, and
Liechty
,
M. P.
, 2007, “
Effects of Fuel Property Changes on Heavy-Duty HCCI Combustion
,”
SAE
Paper No. 2007-01-0191.
9.
Inagaki
,
K.
,
Fuyuto
,
T.
,
Nishikawa
,
K.
, and
Nakakita
,
K.
, 2006, “
Dual-Fuel PCI Combustion Controlled by In-Cylinder Stratification of Ignitability
,”
SAE
Paper No. 2006-01-0028.
10.
Kokjohn
,
S. L.
,
Hanson
,
R.
,
Splitter
,
D.
, and
Reitz
,
R. D.
, 2009, “
Experiments and Modeling of Dual-Fuel HCCI and PCCI Combustion Using In-Cylinder Fuel Blending
,”
SAE
Paper No. 2009-01-2647.
11.
Splitter
,
D.
,
Kokjohn
,
S. L.
,
Rein
,
K.
,
Hanson
,
R.
,
Sanders
,
S.
, and
Reitz
,
R. D.
, 2010, “
An Optical Investigation of Ignition Processes in Fuel Reactivity Controlled PCCI Combustion
,”
SAE
Paper No. 2010-01-0345.
12.
Hanson
,
R.
,
Kokjohn
,
S. L.
,
Splitter
,
D.
, and
Reitz
,
R. D.
, 2010, “
An Experimental Investigation of Fuel Reactivity Controlled PCCI Combustion in a Heavy-Duty Engine
,”
SAE
Paper No. 2010-01-0864.
13.
Splitter
,
D.
,
Hanson
,
R.
,
Kokjohn
,
S. L.
, and
Reitz
,
R. D.
, 2010, “
Improving Engine Performance by Optimizing Fuel Reactivity With a Dual Fuel PCCI Strategy
,”
Proceedings of the THIESEL Conference on Thermo and Fluid Dynamic Processes in Diesel Engines
, September 14–17, Valencia, Spain.
14.
Reitz
,
R. D.
,
Hanson
,
R.
,
Splitter
,
D.
, and
Kokjohn
,
S. L.
, 2010, “
Engine Combustion Control via Fuel Reactivity Stratification
,” University of Wisconsin WARF Patent Application No. P100054US.
15.
Kokjohn
,
S. L.
, and
Reitz
,
R. D.
, 2010, “
Characterization of Dual-Fuel PCCI Combustion in a Light-Duty Engine
,”
Proceedings of the International Multi-Dimensional Engine Modeling User’s Group Meeting
.
16.
Amsden
,
A. A.
, 1997, “
KIVA-3V: A Block-Structured KIVA Program for Engines With Vertical or Canted Valves
,” Los Alamos National Laboratory Report No. LA-13313-MS.
17.
Kee
,
R. J.
,
Rupley
,
F. M.
, and
Miller
,
J. A.
, 1989, “
Chemkin-II: A Fortran Chemical Kinetics Package for the Analysis of Gas Phase Chemical Kinetics
,” Sandia Report No. SAND 89-8009.
18.
Beale
,
J. C.
, and
Reitz
,
R. D.
, 1999, “
Modeling Spray Atomization With the Kelvin-Helmholtz/Rayleigh-Taylor Hybrid Model
,”
Atomization Sprays
,
9
, pp.
623
650
.
19.
Ra
,
Y.
, and
Reitz
,
R. D.
, 2003, “
The Application of a Multicomponent Droplet Vaporization Model to Gasoline Direct Injection Engines
,”
Int. J. Engine Res.
,
4
, pp.
193
218
.
20.
Abani
,
N.
,
Munnannur
,
A.
, and
Reitz
,
R. D.
, 2008, “
Reduction of Numerical Parameter Dependencies in Diesel Spray Models
,”
J. Eng. Gas Turbines Power
,
130
, p.
032809
.
21.
Han
,
Z.
, and
Reitz
,
R. D.
, 1995, “
Turbulence Modeling of Internal Combustion Engines Using RNG k-e Models
,”
Combust. Sci. Technol.
,
106
, pp.
267
295
.
22.
Ra
,
Y.
, and
Reitz
,
R. D.
, 2008, “
A Reduced Chemical Kinetic Model for IC Engine Combustion Simulations With Primary Reference Fuels
,”
Combust. Flame
,
155
, pp.
713
738
.
23.
Ra
,
Y.
, and
Reitz
,
R. D.
, 2011, “
A Combustion Model for IC Engine Combustion Simulations With Multi-Component Fuels
,”
Combust. Flame
,
158
, pp.
69
90
.
24.
Kong
,
S. C.
, and
Reitz
,
R. D.
, 2007, “
Modeling Diesel Spray Flame Liftoff, Sooting Tendency, and NOx Emissions Using Detailed Chemistry With Phenomenological Soot Model
,”
J. Eng. Gas Turbines Power
,
129
, pp.
245
251
.
25.
Sun
,
Y.
, 2007, “
Diesel Combustion Optimization and Emissions Reduction Using Adaptive Injection Strategies (AIS) With Improved Numerical Models
,” Ph.D. thesis, University of Wisconsin-Madison, Madison, WI.
26.
Dempsey
,
A. B.
, and
Reitz
,
R. D.
, 2011, “
Computational Optimization of a Heavy-Duty Compression Ignition Engine Fueled With Conventional Gasoline
,”
SAE
Paper No. 2011-01-0356.
27.
Gamma Technologies, 2009, GT Suite v7.0, Gamma Technologies, Inc., Westmont, IL.
28.
Reaction Design, 2006, CHEMKIN 4.1, San Diego, CA.
29.
Mack
,
J. H.
,
Aceves
,
S. M.
, and
Dibble
,
R. W.
, 2009, “
Demonstrating Direct Use of Wet Ethanol in a Homogeneous Charge Compression Ignition (HCCI) Engine
,”
Energy
,
34
, pp.
782
787
.
30.
Fieweger
,
K.
,
Blumenthal
,
R.
, and
Adomeit
,
G.
, 1997, “
Self-Ignition of S.I. Engine Model Fuels a Shock Tube Investigation at High Pressure
,”
Combust. Flame
,
109
, pp.
599
619
.
31.
Curran
,
H. J.
,
Dunphy
,
M. P.
,
Simmie
,
J. M.
,
Westbrook
,
C. K.
, and
Pitz
,
W. J.
, 1992, “
Shock Tube Ignition of Ethanol, Isobutene, and MTBE: Experiments and Modeling
,”
Proceedings of the Twenty-Fourth International Symposium on Combustion
, pp.
769
776
.
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