Dual fuel engine combustion utilizes a high-cetane fuel to initiate combustion of a low-cetane fuel. The performance and emissions benefits (low NOx and soot emissions) of dual fuel combustion are well-known. Ignition delay (ID) of the injected high-cetane fuel plays a critical role in quality of the dual fuel combustion process. This paper presents experimental analyses of the ID behavior for diesel-ignited propane and diesel-ignited methane dual fuel combustion. Two sets of experiments were performed at a constant engine speed (1800 rev/min) using a four-cylinder direct injection diesel engine with the stock electronic conversion unit (ECU) and a wastegated turbocharger. First, the effects of fuel–air equivalence ratios (Фpilot ∼ 0.2–0.6 and Фoverall ∼ 0.2–0.9) on IDs were quantified. Second, the effects of gaseous fuel percent energy substitution (PES) and brake mean effective pressure (BMEP) (from 2.5 to 10 bars) on IDs were investigated. With constant Фpilot (>0.5), increasing Фoverall with propane initially decreased ID but eventually led to premature propane auto-ignition; however, the corresponding effects with methane were relatively minor. Cyclic variations in the start of combustion (SOC) increased with increasing Фoverall (at constant Фpilot) more significantly for propane than for methane. With increasing PES at constant BMEP, the ID showed a nonlinear trend (initially increasing and later decreasing) at low BMEPs for propane but a linearly decreasing trend at high BMEPs. For methane, increasing PES only increased IDs at all BMEPs. At low BMEPs, increasing PES led to significantly higher cyclic SOC variations and SOC advancement for both propane and methane. Finally, the engine ignition delay (EID), defined as the separation between the start of injection (SOI) and the location of 50% of the cumulative heat release, was also shown to be a useful metric to understand the influence of ID on dual fuel combustion. Dual fuel ID is profoundly affected by the overall equivalence ratio, pilot fuel quantity, BMEP, and PES. At high equivalence ratios, IDs can be quite short, and beyond a certain limit, can lead to premature auto-igniton of the low-cetane fuel (especially for a reactive fuel like propane). Therefore, it is important to quantify dual fuel ID behavior over a range of engine operating conditions.

References

References
1.
Karim
,
G. A.
,
2003
, “
Combustion in Gas Fueled Compression-Ignition Engines of the Dual Fuel Type
,”
ASME J. Eng. Gas Turbines Power
,
125
(
3
), pp.
827
836
.10.1115/1.1581894
2.
Sequera
,
A. J.
,
Parthasarathy
,
R. N.
, and
Golahalli
,
S. R.
,
2011
,
Effects of Fuel Injection Timing in the Combustion of Biofuels in a Diesel Engine at Partial Loads
,”
ASME J. Energy Resour. Technol.
,
133
(
2
), p.
022203
.10.1115/1.4003808
3.
Stewart
,
J.
,
Clarke
,
A.
, and
Chen
,
R.
,
2007
, “
An Experimental Study of the Dual-Fuel Performance of a Small Compression Ignition Diesel Engine Operating With Three Gaseous Fuels
,.
Proc. Inst. Mech. Eng., Part D (J. Automob. Eng.)
,
221
(
8
), pp.
943
956
.10.1243/09544070JAUTO458
4.
Srinivasan
,
K. K.
,
Krishnan
,
S. R.
,
Qi
,
Y.
,
Midkiff
,
K. C.
, and
Yang
,
H.
,
2007
, “
Analysis of Diesel Pilot-Ignited Natural Gas Low-Temperature Combustion With Hot Exhaust Gas Recirculation
,”
Combust. Sci. Technol.
,
179
(
9
), pp.
1737
1776
.10.1080/00102200701259882
5.
Srinivasan
,
K. K.
,
Mago
,
P. J.
,
Zdaniuk
,
G. J.
, and
Chamra
,
L. M.
,
2008
, “
Improving the Efficiency of the Advanced Injection Low Pilot Ignited Natural Gas Engine Using Organic Rankine Cycles
,”
ASME J. Energy Resour. Technol.
,
130
(
2
), p.
022201
.10.1115/1.2906123
6.
Karim
,
G. A.
,
1987
, “
The Dual Fuel Engine
,”
Automotive Engine Alternatives
,
R. L.
Evans
, ed.,
Plenum Press
,
New York
.
7.
Gurgenci
,
H.
, and
Aminossadati
,
S. M.
,
2009
, “
Investigating the Use of Methane as Diesel Fuel in Off-Road Haul Road Truck Operations
,”
ASME J. Energy Resour. Technol.
,
131
(
3
), p.
032202
.10.1115/1.3185350
8.
Papagiannakis
,
R. G.
, and
Hountalas
,
D. T.
,
2003
, “
Experimental Investigation Concerning the Effect of Natural Gas Percentage on Performance and Emissions of a DI Dual Fuel Diesel Engine
,”
Appl. Therm. Eng.
,
23
, pp.
353
365
.10.1016/S1359-4311(02)00187-4
9.
Krishnan
,
S. R.
,
Biruduganti
,
M.
,
Mo
,
Y.
,
Bell
,
S. R.
, and
Midkiff
,
K. C.
,
2002
, “
Performance and Heat Release Analysis of a Pilot-Ignited Natural Gas Engine
,”
Int. J. Eng. Res.
,
3
(
3
), pp.
171
184
.10.1243/14680870260189280
10.
Tao
,
Y.
,
Hodgins
,
K. B.
, and
Hill
,
P. G.
,
1995
, “
NOx Emissions From a Diesel Engine Fueled With Natural Gas
,”
ASME J. Energy Resour. Technol.
,
117
(
4
), pp. 290–296.10.1115/1.2835426
11.
Poonia
,
M. P.
,
Ramesh
,
A.
, and
Gaur
,
R. R.
,
1999
, “
Experimental Investigation of the Factors Affecting the Performance of a LPG—Diesel Dual Fuel Engine
,” SAE Paper No. 1999-01-1123.
12.
Bose
,
P. K.
, and
Banerjee
,
R.
,
2012
, “
An Experimental Investigation on the Role of Hydrogen in the Emission Reduction and Performance Trade-Off Studies in an Existing Diesel Engine Operating in Dual Fuel Mode Under Exhaust Gas Recirculation
,”
ASME J. Energy Resour. Technol.
,
134
(
1
),
012601
.10.1115/1.4005246
13.
Ramadhas
,
A. S.
,
Jayaraj
,
S.
, and
Muraleedharan
,
C.
,
2008
, “
Dual Fuel Mode Operation in Diesel Engines Using Renewable Fuels: Rubber Seed Oil and Coir-Pith Producer Gas
,”
Renewable Energy
,
33
(
9
), pp.
2077
2083
.10.1016/j.renene.2007.11.013
14.
Heywood
,
J. B.
,
1988
,
Internal Combustion Engine Fundamentals
,
McGraw-Hill, Inc.
,
New York, NY
, p.
915
.
15.
Bade Shrestha
,
S. O.
, and
Karim
,
G. A.
,
2006
, “
The Operational Mixture Limits in Engines Fueled With Alternative Gaseous Fuels
,”
ASME J. Energy Resour. Technol.
,
128
(
3
), pp.
223
–228.10.1115/1.2266267
16.
Nielson
,
O. B.
,
Qvale
,
B.
, and
Sorenson
,
S.
,
1987
, “
Ignition Delay in the Dual Fuel Engine
,” SAE Paper No. 870589.
17.
Karim
,
G. A.
,
Jones
,
W.
, and
Raine
,
R. R.
,
1989
, “
An Examination of the Ignition Delay Period in Dual Fuel Engines
,” SAE Paper No. 892140.
18.
Liu
,
Z.
, and
Karim
,
G. A.
,
1995
, “
The Ignition Delay Period in Dual Fuel Engines
,” SAE Paper No. 950466.
19.
Gunea
,
C.
,
Razavi
,
R. M.
, and
Karim
,
G. A.
,
1998
, “
The Effects of Pilot Fuel Quality on Dual Fuel Ignition Delay
,” SAE Paper No. 982453.
20.
Prakash
,
G.
, and
Ramesh
,
A.
,
1999
, “
An Approach for Estimation of Ignition Delay in a Dual Fuel Engine
,” SAE Paper No. 1999-01-0232.
21.
Gibson
,
C. M.
,
Polk
,
A. C.
,
Shoemaker
,
N. T.
,
Srinivasan
,
K. K.
, and
Krishnan
,
S. R.
,
2011
, “
Comparison of Propane and Methane Performance and Emissions in a Turbocharged Direct Injection Dual Fuel Engine
,”
ASME J. Eng. Gas Turbines Power
,
133
(
9
),
092806
.10.1115/1.4002895
22.
Kalghatgi
,
G. T.
,
Risberg
,
P.
, and
Angstrom
,
H. K.
,
2006
, “
Advantages of Fuels With High Resistance to Auto-Ignition in Late-Injection, Low-Temperature, Compression Ignition Combustion
,” SAE Paper No. 2006-01-3385.
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