Abstract

The conversion of existing heavy-duty diesel engines to lean natural-gas (NG) spark ignition can be achieved by replacing the diesel injector with a spark plug and fumigating the NG into the intake manifold. While the original fast-burn diesel chamber will offset the lower NG flame speed, it will result in a two-stage combustion process (a stage inside and another outside the bowl). However, experimental data at more advanced spark timing, equivalence ratio of 0.8, and mean piston speed of 6.5 m/s suggested an additional combustion stage (i.e., three combustion stages). A three-dimensional (3D) computational fluid dynamics (CFD) simulation and a zero-dimensional triple Wiebe-function model were used to better understand the phenomena. While 78% fuel burned inside the bowl, burning rate reduced significantly when the flame approached the squish entrance and the bowl bottom. Moreover, the triple Wiebe-function indicated that the burn inside the squish was also divided into two separate combustion stages, due to the particularities of in-cylinder flow before and after top dead center. The first stage was fast and took place inside the compression stroke. The second took place in the expansion stroke and produced a short-lived increase in the burning rate, probably due to the increasing squish height during the expansion stroke and the increased combustion-induced turbulence, hence the third heat-release peak. Overall, these findings support the need for further investigations of combustion characteristics in such converted engines, to benefit their efficiency and emissions.

References

1.
Gupta
,
M.
,
Bell
,
S.
, and
Tillman
,
S.
,
1996
, “
An Investigation of Lean Combustion in a Natural Gas-Fueled Spark-Ignited Engine
,”
ASME J. Energy Resour. Technol.
,
118
(
2
), pp.
145
151
.10.1115/1.2792706
2.
 
Weaver
,
C. S.
,
1989
, “
Natural Gas Vehicles—A Review of the State of the Art
,”
SAE Paper No. 892133
.10.4271/892133
3.
 
Zuo
,
C.
, and
Zhao
,
J.
,
2001
, “
Development of Diesel Engines Fuelled With Natural Gas
,”
SAE Paper No. 2001-01-3505
.10.4271/2001-01-3505
4.
Reyes
,
M.
,
Tinaut
,
F. V.
,
Gimenez
,
B.
, and
Perez
,
A.
,
2015
, “
Characterization of Cycle-to-Cycle Variations in a Natural Gas Spark Ignition Engine
,”
Fuel
,
140
, pp.
752
761
.10.1016/j.fuel.2014.09.121
5.
Stocchi
,
I.
,
Liu
,
J.
,
Dumitrescu
,
C. E.
,
Battistoni
,
M.
, and
Grimaldi
,
C. N.
,
2019
, “
Effect of Piston Crevices on the Numerical Simulation of a Heavy-Duty Diesel Engine Retrofitted to Natural-Gas Spark-Ignition Operation
,”
ASME J. Energy Resour. Technol.
,
141
(
11
), p.
112204
.10.1115/1.4043709
6.
 
Meyer
,
R.
,
Meyers
,
D.
,
Shahed
,
S. M.
, and
Duggal
,
V. K.
,
1992
, “
Development of a Heavy Duty on-Highway Natural Gas-Fueled Engine
,”
SAE Paper No. 922362
.10.4271/922362
7.
Heywood
,
J. B.
,
1988
,
Internal Combustion Engine Fundamentals
,
McGraw-Hill
,
New York
.
8.
Li
,
H.
, and
Karim
,
G. A.
,
2005
, “
Exhaust Emissions From a Gas-Fuelled SI Engine
,”
Int. J. Green Energy
,
2
(
1
), pp.
129
145
.10.1081/GE-200051319
9.
 
Jones
,
M. K.
, and
Heaton
,
D. M.
,
1989
, “
Nebula Combustion System for Lean Burn Spark Ignited Gas Engines
,”
SAE Paper No. 890211
.10.4271/890211
10.
Liu
,
J.
,
2018
, “
Investigation of Combustion Characteristics of a Heavy-Duty Diesel Engine Retrofitted to Natural Gas Spark Ignition Operation
,”
Ph.D. dissertation
, West Virginia University, Morgantown, WV.10.33915/etd.3713
11.
Dumitrescu
,
C. E.
,
Padmanaban
,
V.
, and
Liu
,
J.
,
2018
, “
An Experimental Investigation of Early Flame Development in an Optical SI Engine Fueled With Natural Gas
,”
ASME J. Eng. Gas Turbines Power
,
140
(
8
), p.
082802
.10.1115/1.4039616
12.
Donateo
,
T.
,
Tornese
,
F.
, and
Laforgia
,
D.
,
2013
, “
Computer-Aided Conversion of an Engine From Diesel to Methane
,”
Appl. Energy
,
108
, pp.
8
23
.10.1016/j.apenergy.2013.03.002
13.
Liu
,
J.
, and
Dumitrescu
,
C. E.
,
2019
, “
Combustion Partitioning Inside a Natural Gas Spark Ignition Engine With a Bowl-in-Piston Geometry
,”
Energy Convers. Manage.
183
, pp.
73
83
.10.1016/j.enconman.2018.12.118
14.
Liu
,
J.
, and
Dumitrescu
,
C. E.
,
2019
, “
Methodology to Separate the Two Burn Stages of Natural-Gas Lean Premixed-Combustion Inside a Diesel Geometry
,”
Energy Convers. Manage.
,
195
, pp.
21
31
.10.1016/j.enconman.2019.04.091
15.
Elgin
,
R. C.
,
Turner
,
C. W.
, and
Hagen
,
C. L.
,
2013
, “
Combustion Chamber Design Considerations for a Compression Ignition Engine to Spark Ignited Natural Gas Engine Conversion
,”
Western States Section of the Combustion Institute—Fall Technical Meeting
,
Fort Collins, CO
, Oct. 7–8, Paper No. 13F-41.
16.
 
Verma
,
I.
,
Bish
,
E.
,
Kuntz
,
M.
,
Meeks
,
E.
,
Puduppakkam
,
K.
,
Naik
,
C.
, and
Liang
,
L.
,
2006
, “
CFD Modeling of Spark Ignited Gasoline Engines—Part 1: Modeling the Engine Under Motored and Premixed-Charge Combustion Mode
,”
SAE Paper No. 2016-01-0591
.10.4271/2016-01-0591
17.
Han
,
Z.
, and
Reitz
,
R. D.
,
1995
, “
Turbulence Modeling of Internal Combustion Engines Using RNG k-ε Models
,”
Combust. Sci. Technol.
,
106
(
4–6
), pp.
267
295
.10.1080/00102209508907782
18.
Yakhot
,
V.
, and
Orszag
,
S. A.
,
1986
, “
Renormalization Group Analysis of Turbulence. I. Basic Theory
,”
J. Sci. Comput.
,
1
(
1
), pp.
3
51
.10.1007/BF01061452
19.
 
Fan
,
L.
,
Li
,
G.
,
Han
,
Z.
, and
Reitz
,
R. D.
,
1999
, “
Modeling Fuel Preparation and Stratified Combustion in a Gasoline Direct Injection Engine
,”
SAE Paper No. 1999-01-0175
.10.4271/1999-01-0175
20.
Peters
,
N.
,
2000
,
Turbulent Combustion
,
Cambridge University Press
,
Cambridge, UK
.
21.
 
Tan
,
Z.
, and
Reitz
,
R. D.
,
2003
, “
Modeling Ignition and Combustion in Spark-Ignition Engines Using a Level Set Method
,”
SAE Paper No. 2003-01-0722
.10.4271/2003-01-0722
22.
Tan
,
Z.
, and
Reitz
,
R. D.
,
2006
, “
An Ignition and Combustion Model Based on the Level-Set Method for Spark Ignition Engine Multidimensional Modeling
,”
Combust. Flame
,
145
(
1–2
), pp.
1
15
.10.1016/j.combustflame.2005.12.007
23.
 
ANSYS
,
2016
, “
ANSYS Forte 17.2
,”
ANSYS
,
San Diego, CA
.
24.
Yasar
,
H.
,
Soyhan
,
H. S.
,
Walmsley
,
H.
,
Head
,
B.
, and
Sorusbay
,
C.
,
2008
, “
Double-Wiebe Function: An Approach for Single-Zone HCCI Engine Modeling
,”
Appl. Therm. Eng.
,
28
(
11–12
), pp.
1284
1290
.10.1016/j.applthermaleng.2007.10.014
25.
Yeliana
,
Y.
,
Cooney
,
C.
,
Worm
,
J.
,
Michalek
,
D. J.
, and
Naber
,
J. D.
,
2011
, “
Estimation of double-Wiebe Function Parameters Using Least Square Method for Burn Durations of Ethanol-Gasoline Blends in Spark Ignition Engine Over Variable Compression Ratios and EGR Levels
,”
Appl. Therm. Eng.
,
31
(
14–15
), pp.
2213
2220
.10.1016/j.applthermaleng.2011.01.040
26.
Tolou
,
S.
,
Vedula
,
R. T.
,
Schock
,
H.
,
Zhu
,
G.
,
Sun
,
Y.
, and
Kotrba
,
A.
,
2018
, “
Combustion Model for a Homogeneous Turbocharged Gasoline Direct-Injection Engine
,”
ASME J. Eng. Gas Turbines Power
,
140
(
10
), p.
102804
.10.1115/1.4039813
27.
Cooney
,
C.
,
Worm
,
J.
,
Michalek
,
D.
, and
Naber
,
J.
,
2018
, “
Wiebe Function Parameter Determination for Mass Fraction Burn Calculation in an Ethanol-Gasoline Fuelled SI Engine
,”
J. KONES
,
15
(
3
), pp.
567
574
.https://kones.eu/ep/2008/vol15/no3/JO%20KONES%202008%20NO.%203%20VOL.%2015%20VELIANA.pdf
28.
Xu
,
S.
,
Anderson
,
D.
,
Hoffman
,
M.
,
Prucka
,
R.
, and
Filipi
,
Z.
,
2017
, “
A Phenomenological Combustion Analysis of a Dual-Fuel Natural-Gas Diesel Engine
,”
Proc. Inst. Mech. Eng., Part D
,
231
, pp.
66
83
.10.1177/0954407016633337
29.
Liu
,
J.
, and
Dumitrescu
,
C. E.
,
2019
, “
Single and Double Wiebe Function Combustion Model for a Heavy-Duty Diesel Engine Retrofitted to Natural-Gas Spark-Ignition
,”
Appl. Energy
,
248
, pp.
95
103
.10.1016/j.apenergy.2019.04.098
30.
 
Liu
,
J.
, and
Dumitrescu
,
C. E.
,
2019
, “
Multiple Combustion Stages Inside a Heavy-Duty Diesel Engine Retrofitted to Natural-Gas Spark-Ignition Operation
,”
ASME Paper No. GTP-19-1227
.10.1115/GTP-19-1227
31.
Liu
,
J.
, and
Dumitrescu
,
C. E.
,
2019
, “
Improved Thermodynamic Model for Lean Natural-Gas Spark-Ignition in a Diesel Engine Using a Triple Wiebe Function
,”
ASME J. Energy Resour. Technol.
,
142
(
6
), p.
062303
.10.1115/1.4045534
You do not currently have access to this content.