$*5,&8/785$/(1*,1((5,1*
EFFECT OF IGNITION TIMING ON EMISSIONS OF
63$5.,*1,7,21(1*,1(86,1*()8(/
Maris Gailis, Vilnis Pirs
Latvia University of Agriculture
maris.gailis@llu.lv; vilnis.pirs@llu.lv
Abstract
7KLVH[SHULPHQWDOVWXG\DVVHVVHVWKHLQÀXHQFHRILJQLWLRQWLPLQJRQHPLVVLRQVIURPDSURGXFWLRQIRXUF\OLQGHUSRUW
injection spark ignition engine. The aim of this research was to evaluate the necessity of ignition timing correction
ZKHQWKHUHJXODUJDVROLQHYHKLFOHLVEHLQJDGDSWHGIRUWKHXVHRI(IXHO7HVWVZHUHFRQGXFWHGLQWKH$OWHUQDWLYH
)XHOV5HVHDUFK/DERUDWRU\RI/DWYLD8QLYHUVLW\RI$JULFXOWXUHLQ'HFHPEHU7KHHQJLQHZDVIXHOOHGZLWKWKH
HWKDQROJDVROLQH EOHQG ( RU WKH FRPPHUFLDO JDVROLQH$7KH HQJLQH ZDV WHVWHG ZLWKLQ D YHKLFOH LQ D FKDVVLV
G\QDPRPHWHULQVWHDG\VWDWHFRQGLWLRQVZKLFKUHVHPEOHGULYLQJDWNPK and 90 km h. The original engine
FRQWUROXQLWZDVUHSODFHGZLWKDSURJUDPPDEOHRQH(QJLQHRXWDQGWDLOSLSHH[KDXVWJDVVDPSOHVZHUHWDNHQDQG
DQDO\VHGZLWKD)7,5W\SHDQDO\VHU$9/6(6$0&DUERQPRQR[LGH&2XQEXUQHGK\GURFDUERQV+&QLWURJHQ
R[LGHV12[DFHWDOGHK\GHDQGXQEXUQHGHWKDQROHPLVVLRQYROXPHWULFVKDUHLVSUHVHQWHG&2+&DQGDFHWDOGHK\GH
HPLVVLRQVZHUHQRWDIIHFWHGE\YDULDWLRQRIWKHLJQLWLRQWLPLQJZLWKLQWKHWHVWHGUDQJH12[DQGHWKDQROHPLVVLRQV
ZHUHUHGXFHGZLWKWKHLJQLWLRQWLPLQJUHWDUG7KHHPLVVLRQVRI&2+&DQG12[ZHUHUHGXFHGZKHQWKHHQJLQHZDV
IXHOOHGZLWKWKH(IXHOFRPSDULQJZLWKWKHJDVROLQHXVH,JQLWLRQWLPLQJRSWLPL]HGIRUWKHJDVROLQHZDVIRXQG
VXLWDEOHIRUWKH(IXHOIURPWKHHPLVVLRQDQDO\VHVSRLQW
.H\ZRUGV: ethanol, ignition timing advance, emissions.
,QWURGXFWLRQ
The biofuels are increasingly used as the energy
source in the light passenger vehicles. The biofuels are
considered as renewable energy source and contribute
to the reduction of the greenhouse gas emissions
&RVWDJOLRODHWDO7KHHWKDQROKDVEHHQNQRZQ
as a suitable fuel for the spark ignition engines since
the 19th century. Currently all commercially available
JDVROLQHLQ/DWYLDLVEOHQGHGZLWKWKHHWKDQROLQ
m·mYROXPHUDWLR2QHRIWKHEHQH¿WVRIHWKDQROXVH
DVDIXHOLVWKHUHGXFWLRQRIGHSOHWLRQRIQRQUHQHZDEOH
energy resources. By adding ethanol, oxygen is
blended into the fuel which favours the combustion of
the gasoline, reducing toxicity of the emissions. The
use of pure ethanol as the fuel is problematic due to
WKHHQJLQHFROGVWDUWGLI¿FXOWLHVEHORZƒ&*DVROLQH
RQUDWLRP·m is added to anhydrous ethanol to
facilitate cold starting and act as a denaturing agent.
5HVXOWHGIXHOLVGHVLJQDWHG(DQGLVDYDLODEOHLQWKH
service stations in many parts of the world, including
Latvia. Due to the physiochemical differences of
JDVROLQHDQGHWKDQROWKHXVHRI(UHTXLUHVYHKLFOH
adaptation. Specially designed production vehicles
)OH[LEOH )XHO 9HKLFOHV RU ))9 FDQ XVH JDVROLQH
(RUPL[WXUHRIERWKLQDQ\UDWLR,WLVSRVVLEOHWR
FRQYHUWUHJXODUJDVROLQHYHKLFOHIRUXVHRI(IXHO
1RUPDOO\ VXFK FRQYHUWLQJ LV OLPLWHG WR LQFUHDVH RI
the fuel supply. Ignition parameters are usually left
unchanged.
Engine tailpipe emissions of the vehicle,
FRQYHUWHGWRXVHRI(PXVWEHDVORZDVSRVVLEOH
and certainly within legal limits. Depending on the
vehicle production date, different standards apply
IRU DFFHSWDEOH OHYHO RI FHUWDLQ VRFDOOHG µUHJXODWHG¶
212
emission gas components. Currently those emission
JDV FRPSRQHQWV DUH QLWURJHQ R[LGHV 12[ FDUERQ
PRQR[LGH &2 WRWDO K\GURFDUERQV +& QRQ
PHWKDQH K\GURFDUERQV 10+& DQG SDUWLFXODWH
matter (PM). Ignition timing is known to be one
of the factors that affect engine emissions (Heywood,
&RPEXVWLRQ RI WKH DLUIXHO PL[WXUH LQ WKH
combustion chamber must occur in a certain
moment of engine operating phase, to push piston
GRZQZDUGV DQG HI¿FLHQWO\ FRQYHUW FKHPLFDO HQHUJ\
into mechanical energy. Due to the delay of ignition
and duration of the combustion, ignition spark must
be supplied with certain advance, depending on the
engine design and operating conditions. Peak cylinder
pressure and therefore temperature of combustion and
exhaust gases are affected by spark timing. Timing,
which provides maximal peak cylinder pressure, also
provides maximal brake torque (MBT) (Heywood,
'HSHQGLQJRQWKHHQJLQHGHVLJQFRQGLWLRQVRI
MBT may not provide optimally balanced emissions.
Usually in production engines ignition timing is
retarded from MBT. Retarded timing lowers burning
temperature and increases temperature of exhaust
JDVHV/RZHUEXUQLQJWHPSHUDWXUHFDQGHFUHDVH12[
emissions. Increased exhaust gas temperature can
UHGXFHK\GURFDUERQHPLVVLRQV+H\ZRRG
K. Silaipillayarputhur and S.A. Idem (2011)
found that combustion duration increases with the
engine speed. As combustion duration increases,
engine output power decreases, because the cycle
diagram further deviates from ideal Otto cycle. If
the combustion duration increases, ignition advance
must be also increased to maximize engine output
5(6($5&+)25585$/'(9(/230(1792/80(
())(&72),*1,7,217,0,1*21(0,66,2162)
63$5.,*1,7,21(1*,1(86,1*()8(/
SRZHU'HOD\RILJQLWLRQDQGFRPEXVWLRQÀDPHVSHHG
LV GLIIHUHQW IRU HWKDQRO DQG JDVROLQH /DPLQDU ÀDPH
VSHHGRIUHJXODUJDVROLQHLVPVDQGPV for
HWKDQRO+DUDDQG7DQRXH7XUQHUHWDO
Therefore, using ignition advance parameters, which
DUH RSWLPDO IRU JDVROLQH RSHUDWLRQ ZLOO OHDG WR QRQ
optimal operation on fuel with high ethanol content,
VXFKDV(
C. Sayin (2012) evaluated the impact of varying
spark timing on the performance and emissions
of a gasoline engine. He found a decrease of brake
WKHUPDOHI¿FLHQF\DQGLQFUHDVHRIEUDNHVSHFL¿FIXHO
consumption, emissions of CO and hydrocarbons
(HC), when gasoline with higher research octane
QXPEHU 521 WKDQ WKH UHTXLUHPHQW RI DQ HQJLQH
was used at a nominal spark timing. The increase
RI LJQLWLRQ DGYDQFH IRU JDVROLQH ZLWK KLJKHU 521
boosted engine power and decreased emissions of CO
and HC, and decreased fuel consumption.
7 7RSJO HW DO VWXGLHG WKH HIIHFWV RI
JDVROLQH DQG JDVROLQHHWKDQRO EOHQGV RQ D VLQJOH
cylinder spark ignition engine performance and
emissions. Experiments were conducted at a constant
speed in wide open throttle mode. They concluded
WKDWXVLQJ(IXHOLJQLWLRQWLPLQJKDGWREHUHWDUGHG
by 4 degrees, comparing to the use of pure gasoline
E0, to achieve maximal brake torque. The increase of
ethanol content in the fuel led to a decrease of exhaust
gas temperature. CO emissions were reduced with
an increase of ethanol content. They found increase
of HC emissions with increase of ethanol content.
Slight decrease of HC emissions was found when the
ignition timing was retarded.
17UN|]HWDOFRQGXFWHGH[SHULPHQWVRQ
F\OLQGHUFDUEXUHWWRU6,HQJLQHXVLQJ(IXHO7KH\
investigated the effect of ignition timing advance on
the engine performance and emissions. They reported
best engine performance and emissions when ignition
timing was advanced by 4 degrees, comparing to use
RISXUHJDVROLQH12[HPLVVLRQVZHUHLQFUHDVHGZLWK
increase of ignition advance, CO and CO2 emissions
were mainly unaffected and HC emissions increased
with ignition retarding.
From the literature review, the impact of the spark
WLPLQJRQHPLVVLRQVRI6,HQJLQHUXQQLQJRQ(IXHO
is not clearly studied. Some researchers are conducting
experiments with carburettor engines, in wide open
throttle mode. Wide open throttle operating conditions
are rarely used in real life. Results of optimal ignition
timing for high ethanol content fuel, comparing with
gasoline are contradictory. The authors of this study
investigated the effect of ignition timing advance on
modern SI engine emissions in conditions, which
resemble regular driving. The aim of this research is
WRHYDOXDWHWKHQHFHVVLW\RILJQLWLRQWLPLQJ¿QHWXQLQJ
IRU ( ZKHQ WKH UHJXODU JDVROLQH HQJLQH LV EHLQJ
0DULV*DLOLV9LOQLV3LUV
DGDSWHGIRUXVHZLWK(2QO\WKHHIIHFWRQHPLVVLRQV
is investigated.
0DWHULDOVDQG0HWKRGV
Tests were performed using two different fuels,
purchased at the commercial fuel stations. Main
properties of the test fuels were obtained from the
FHUWL¿FDWHV SURYLGHG E\ WKH IXHO VXSSOLHUV *DVROLQH
$RI(1VWDQGDUGKDGUHVHDUFKRFWDQHQXPEHU
521 PRWRU RFWDQH QXPEHU 021 DQG
HWKDQROFRQWHQWP m(KDG521DQG021
DERYHHWKDQROFRQWHQWP m.
Conventional port injection SI engine was used.
7KH VSHFL¿FDWLRQV RI WKH HQJLQH DQG WKH YHKLFOH DUH
listed in Table 1. The original engine control module
(&8ZDVUHSODFHGE\DSURJUDPPDEOH(&89(06
9WRPDLQWDLQWKHHQJLQHRSHUDWLQJSDUDPHWHUVZLWKLQ
the required limits. The original narrowband oxygen
sensor was replaced by a wideband sensor Bosch LSU
4.2. The original catalytic converter was retained.
Table 1
0DLQVSHFL¿FDWLRQVRIWHVWDXWRPRELOH
Parameter
Model
,GHQWL¿FDWLRQQXPEHU
Date of production
Engine
9DOXH
Renault Twingo
9)&$(
7\SH')F\OLQGHU
YDOYH
Displacement volume,
1149
cm
Piston bore / stroke,
mm
9ROXPHWULFFRPSUHVVLRQ
ratio
Gearbox
7\SH-%JHDUPDQXDO
)LQDOGULYH
Gear ratios
4th JHDU
WKJHDU
The engine was tested within the automobile. Load
conditions were simulated in the laboratory on the
edgy current roll type chassis dynamometer Mustang
0' 7KH H[KDXVW JDV WHPSHUDWXUH (*7 ZDV
measured in engine exhaust manifold. Engine exhaust
emission gas samples were taken before the catalytic
converter and from the tailpipe. Composition of
exhaust gas was analysed with the Fourier transform
LQIUDUHG VSHFWURPHWHU )7,5$9/ 6(6$0$ EHDP
of wide spectrum infrared light is passed through the
cooled and dried sample gas. The amount of energy
DEVRUEHG DW HDFK VLJQL¿FDQW ZDYHOHQJWK LV DQDO\VHG
Signatures of absorbed wavelength and relation of
DEVRUEHG HQHUJ\ WR WKH YROXPH RI WKH VSHFL¿F JDV
component was recorded during factory calibration
of the equipment. Composition and concentration of
5(6($5&+)25585$/'(9(/230(1792/80(
())(&72),*1,7,217,0,1*21(0,66,2162)
63$5.,*1,7,21(1*,1(86,1*()8(/
0DULV*DLOLV9LOQLV3LUV
the sample gas is determined using matrix calculation
methods, comparing sample and calibration data.
Measurement system allows for simultaneous
PHDVXUHPHQW RI JDV FRPSRQHQWV ZLWK VDPSOLQJ
rate 1 Hz. Results of the testing were expressed as a
concentration timeline in volume unit share, parts per
PLOOLRQ SSP 9ROXPH VKDUHV RI WRWDO +& DQG 12[
ZHUH FDOFXODWHG E\ $9/ 6(6$0 V\VWHP VRIWZDUH
The results are not directly comparable to the results,
obtained using other methods.
Wheel speed, power and torque were recorded
using chassis dynamometer control software. The
HQJLQH VSHHG H[KDXVW JDV WHPSHUDWXUH DQG DLUIXHO
ratio were registered with ECU monitoring software
9(067XQH
Dynamometer was set at a constant speed mode,
WKURWWOH RSHQLQJ ZDV ¿[HG WR UHDFK WKH UHTXLUHG
SUHVVXUH LQ WKH LQOHW PDQLIROG 9DULDWLRQ RI ZKHHO
power and torque between different test conditions
ZDVVWDWLVWLFDOO\LQVLJQL¿FDQWDQGEH\RQGWKHSUHFLVLRQ
of chassis dynamometer measurement system.
Before testing, the ignition timing advance
was mapped for maximal break torque (MBT) at
VWRLFKLRPHWULF DLUIXHO UDWLR IRU ERWK IXHOV ( DQG
gasoline. Detonation limits were not reached at chosen
test conditions. Series of road tests were performed
WR¿QGHQJLQHORDGFRQGLWLRQVIRUWZRW\SLFDOGULYLQJ
PRGHVDWNPāK and 90 km·h steady driving on
DÀDWURDG$OOWHVWVZHUHSHUIRUPHGDWVWRLFKLRPHWULF
DLUIXHO UDWLR 7KUHH WHVW SRLQWV RI LJQLWLRQ WLPLQJ
advance, expressed in crank degrees before top dead
centre (CA BTDC), at both driving modes were used:
x Timing set by vehicle producer for gasoline
(nominal timing);
x 7LPLQJ IRU PD[LPDO EUDNH WRUTXH IRU (
0%7(
x Timing for maximal brake torque for gasoline
0%7$
Testing was conducted in steady state conditions,
listed in Table 2.
Table 2
7HVWFRQGLWLRQV
Parameter
:KHHOVSHHGNPîK
Engine speed, min
Gear
:KHHOEUDNHWRUTXH1îP
Wheel brake power, kW
Ignition timing advance,
nominal setting, degrees CA
BTDC
Ignition timing advance, MBT
(GHJUHHV&$%7'&
Ignition timing advance, MBT
gasoline, degrees CA BTDC
214
Settings 1
4th
Settings 2
90
WK
The vehicle was driven on the chassis dynamometer
LQ VHOHFWHG FRQGLWLRQV IRU VHFRQGV EHIRUH WKH
actual measuring started. Each test lasted 40 seconds
DQGZDVUHSHDWHGWLPHV$ULWKPHWLFPHDQRIYDOLG
WHVWUHVXOWVZDVXVHGDVDUHVXOW&RQ¿GHQFHLQWHUYDOV
ZHUHFDOFXODWHGIRUFRQ¿GHQFHOHYHO
5HVXOWVDQG'LVFXVVLRQ
Temperature of the exhaust gases depends on an
average temperature in the combustion chamber and
timing of combustion in the engine cycle. Decrease
of EGT is attributed to higher ignition timing
advance (Fig. 1). Higher ignition advance increases
maximal pressure and peak temperature in
FRPEXVWLRQ FKDPEHU +H\ZRRG 7KLV HIIHFW
GRHV QRW GLUHFWO\ UHÀHFW RQ (*7 $V ZLWK KLJKHU
timing advance combustion starts earlier in the engine
cycle, larger part of oxidation reaction chain takes
place inside the cylinder, which causes decrease
of EGT. Ethanol has higher heat of evaporation
comparing to gasoline (Turner et al., 2011). It can be
attributed to the decrease of EGT when engine was
WHVWHGZLWK(IXHO
)LJXUH7HPSHUDWXUHRIHQJLQHRXWH[KDXVWJDVHV
ignition timing: ȃ«ȏ«ȃ«
Hydrocarbon emissions consist of unburned fuel
in gaseous state. HC emissions are largely caused
E\ SDUWLDO RU FRPSOHWH PLV¿UH (PLVVLRQV RI +& DUH
known to increase in light load, low engine speed
conditions (Sayin, 2012). Chain of oxidation reactions
of hydrocarbons continues during exhaust stroke and
outside of the cylinder. Therefore variations of HC
emissions are related to variations of EGT (Heywood,
+&HPLVVLRQVZHUHLQVLJQL¿FDQWO\DIIHFWHGE\
changing of ignition timing at selected test conditions
IRUERWKIXHOV)LJ)LJ
5(6($5&+)25585$/'(9(/230(1792/80(
())(&72),*1,7,217,0,1*21(0,66,2162)
63$5.,*1,7,21(1*,1(86,1*()8(/
0DULV*DLOLV9LOQLV3LUV
200
200
150
81
77
80
100
50
54
50
400
239
238
238
285
301
286
600
Volume Unit Share, cm3˜m-3
˜
652
669
671
800
250
b
111
118
106
930
944
942
Volume Unit Share, cm3˜m-3
˜
1 000
a
220
214
231
300
1 200
50
0
0
A95 50
E85 50 A95 90 E85 90
Testing Mode
A95 50
E85 50 A95 90 E85 90
Testing Mode
6 000
4 000
2 000
0
4 000
b
3 404
3 635
3527
3 805
3 688
3784
5 000
5 368
5 072
5378
6 000
5 893
5 634
5830
˜
Volume Unit Share,
10 070
9 982
10059
7 000
cm3˜m-3
8 000
a
8 506
8 684
8836
Volume Unit Share, cm3˜m-3
10 000
8 328
7 456
8311
˜
12 000
9 394
9 766
9423
Figure 2. HC volume share:
DHQJLQHRXWEWDLOSLSHLJQLWLRQWLPLQJȃ«ȏ«ȃ«
3 000
2 000
1 000
0
A95 50
A95 50
E85 50 A95 90 E85 90
Testing Mode
E85 50 A95 90 E85 90
Testing Mode
)LJXUH&2YROXPHVKDUH
DHQJLQHRXWEWDLOSLSHLJQLWLRQWLPLQJȃ«ȏ«ȃ«
5(6($5&+)25585$/'(9(/230(1792/80(
˜
+H\ZRRG7KHDPRXQWRI&2HPLVVLRQVZHUH
LQVLJQL¿FDQWO\DIIHFWHGE\YDULDWLRQRILJQLWLRQWLPLQJ
ZLWKLQ WKH WHVWHG UDQJH )LJ )LJ 7KH DPRXQW
RI&2HQJLQHRXWHPLVVLRQVZHUHUHGXFHGE\
FRPSDULQJ(XVHZLWKJDVROLQH
7KH SULQFLSDO VRXUFH RI 12 DQG 122 (which are
VXPPHGDV12[LVWKHR[LGDWLRQRIQLWURJHQGXULQJ
the peak temperature phase at the beginning of the
H[SDQVLRQVWURNH(PLVVLRQVRI12[DUHQRWDGLUHFW
product of fuel combustion but rather a side effect.
,JQLWLRQ WLPLQJ KDV D VLJQL¿FDQW LQÀXHQFH RQ WKH
combustion temperature.
If the timing is retarded, ignition places combustion
in a later point of engine cycle, when the piston has
˜
˜
˜
$SSDUHQWO\ PLV¿UH UDWH GLG QRW FKDQJH ZLWKLQ
the tested ignition timing range. Slight increase of
exhaust gas temperature with ignition timing retard
did not have effect on the reduction of HC emissions.
+&HQJLQHRXWHPLVVLRQVZHUHUHGXFHGE\E\
YROXPHXVLQJ(LQVWHDGRIJDVROLQH)LJ+LJKHU
EGT, engine speed and load in 90 km h test mode
were attributed to the reduction of HC emissions.
CO formation is one of the steps of burning of
hydrocarbons. Oxidation of CO to CO2 requires
UHODWLYHO\ KLJK WHPSHUDWXUH DERYH . :KHQ WKH
temperature in the combustion chamber falls as a result
of advancement of expansion stroke, some amount of
CO is not oxidised and forms part of exhaust gases
())(&72),*1,7,217,0,1*21(0,66,2162)
63$5.,*1,7,21(1*,1(86,1*()8(/
52
31
17
24
11
10
1
500
20
0
1
1 000
30
10
1 500
24
25
˜
40
35
50
42
b
Volume Unit Share, cm3˜m-3
2 000
1 468
1 782
1827
2 500
1 788
2 005
2165
3 000
˜
Volume Unit Share, cm3˜m-3
3 500
60
a
2 404
2 542
2838
2 863
3 061
3319
0DULV*DLOLV9LOQLV3LUV
0
A95 50
E85 50 A95 90 E85 90
A95 50
Testing Mode
)LJXUH12[YROXPHVKDUH
E85 50 A95 90 E85 90
Testing Mode
DHQJLQHRXWEWDLOSLSHLJQLWLRQWLPLQJȃ«ȏ«ȃ«
20
0
2.5
1.6
1.6
1.4
1.1
0.9
0.7
1
0.6
2
1.4
3
1.2
0.9
32
32
35
60
40
b
˜
80
Volume Unit Share, cm3˜m-3
81
83
85
98
a
2.8
112
100
38
39
39
Volume Unit Share,
95
˜
120
cm3˜m-3
4
0
A95 50
E85 50 A95 90 E85 90
A95 50
E85 50
A95 90
E85 90
)LJXUH$FHWDOGHK\GHYROXPHVKDUH
Testing
Mode
Testing Mode
DHQJLQHRXWEWDLOSLSHLJQLWLRQWLPLQJȃ«ȏ«ȃ«
˜
˜
LQVWHDG RI JDVROLQH DW RULJLQDO VSDUN WLPLQJ DQGGHJUHHV&$%7'&DFFRUGLQJO\ZDVQRWHG
IRU HQJLQHRXW DQG IRU WDLOSLSH
emissions.
Aldehydes in the engine combustion chamber
DUH IRUPHG E\ FOHDYDJHV RI && RU &+ ERQGV
of hydrocarbons at high temperatures and partial
R[LGDWLRQRIHWKDQRO:DJQHUDQG:\V]\QVNL
The amount of acetaldehyde is known to raise with
increase of ethanol content in fuel (Kumar et al.,
2011). Test results demonstrated agreement with that
LQHQJLQHRXWHPLVVLRQV)LJ
˜
˜
already started downward movement. Peak pressure
and temperature is therefore reduced (Heywood,
7HVW UHVXOWV VKRZHG D VLJQL¿FDQW GHSHQGHQFH
RI 12x emissions on the spark timing (Fig. 4; Fig.
5HWDUGLQJ RI LJQLWLRQIURP 0%7 SRLQW GHFUHDVHG
12[ HPLVVLRQV LQ DOO WHVW FRQGLWLRQV 5HGXFHG 12[
HPLVVLRQ OHYHO ZDV REVHUYHG ZKHQ ( ZDV XVHG
instead of gasoline. This can be explained by lower
peak temperature in the combustion chamber. The
original ignition timing, tuned for lower emissions
XVLQJ JDVROLQH ZDV DOVR HIIHFWLYH ZKHQ ( ZDV
XVHG 7KH UHGXFWLRQ RI 12[ HPLVVLRQV XVLQJ (
5(6($5&+)25585$/'(9(/230(1792/80(
())(&72),*1,7,217,0,1*21(0,66,2162)
63$5.,*1,7,21(1*,1(86,1*()8(/
0DULV*DLOLV9LOQLV3LUV
35
50
0
E85 50
22
20
15
5
10
4
100
25
9
150
b
14
˜
Volume Unit Share,
cm3˜m-3
183
164
200
175
250
30
241
232
˜
Volume Unit Share,
cm3˜m-3
300
a
13
291
350
5
0
E85 90
Testing Mode
E85 50
E85 90
Testing Mode
)LJXUH8QEXUQHGHWKDQROYROXPHVKDUH
DHQJLQHRXWEWDLOSLSHLJQLWLRQWLPLQJȃ«ȏ«ȃ«
100
a
90
73
68
70
80
63
60
47
50
40
34
30
22
20
10
b
90
11
37
32
21
14
Reduction by volume, %
Reduction by volume, %
80
100
98
0
0
70
64
60
69
63
50
50
39
40
35 37
30
20
18 16
11
16
10
0
NOx
HC
CO
Emission Gas Components
NOx
HC
CO
Emission Gas Components
)LJXUH&RPSDULVRQRIUHGXFWLRQRIUHJXODWHGHPLVVLRQVXVLQJ(ZLWKGLIIHUHQWLJQLWLRQWLPLQJ
DWLPLQJIRU0%7IRU(DQGQRPLQDOWLPLQJIRUJDVROLQHEQRPLQDOWLPLQJIRU(DQGJDVROLQH
test conditions: ȃNPuhHQJLQHRXWȃNPuh tailpipe,
ȃ 90 km uhHQJLQHRXWȏ 90 km uh tailpipe.
Analysis of tailpipe emissions showed high
HI¿FLHQF\ RI R[LGLVLQJ FDWDO\WLF FRQYHUWHU LQ WKH
removal of acetaldehyde emissions. Emission levels
DW WDLOSLSH GLG FRUUHODWH GLUHFWO\ ZLWK HQJLQHRXW
emissions of acetaldehyde. From the results it was
concluded, that the ignition timing has no statistically
VLJQL¿FDQWHIIHFWRQHPLVVLRQVRIDFHWDOGHK\GH
Emissions of unburned ethanol were tested only
ZLWK ( IXHO 5HWDUGHG LJQLWLRQ WLPLQJ DWWULEXWHG
WR WKH UHGXFWLRQ RI HWKDQRO HQJLQHRXW DQG WDLOSLSH
emissions in 90 km h WHVW PRGH )LJ ,W FDQ EH
explained with a higher average temperature in the
combustion chamber and exhaust gases due to higher
speed and load. When the exhaust gas temperature is
high enough for oxidation of ethanol, the variation of
temperature, caused by ignition timing, takes effect.
Retarding of the ignition timing moves the start of
ignition later in engine cycle, exhaust gas temperature
is higher, and the amount of unburned ethanol is
reduced in emissions.
5(6($5&+)25585$/'(9(/230(1792/80(
0DULV*DLOLV9LOQLV3LUV
())(&72),*1,7,217,0,1*21(0,66,2162)
63$5.,*1,7,21(1*,1(86,1*()8(/
Ignition timing for maximal brake torque using 1LWURJHQR[LGHHPLVVLRQVZHUHUHGXFHGE\
IRUHQJLQHRXWDQGIRUWDLOSLSHHPLVVLRQV
(LQHQJLQHRSHUDWLQJFRQGLWLRQVZKHUHGHWRQDWLRQV
XVLQJ(IXHODWQRPLQDOVSDUNWLPLQJFRPSDULQJ
do not occur, have to be retarded, comparing to similar
to maximal brake torque timing.
JDVROLQHVHWXS5HJXODWHGHPLVVLRQVXVLQJ(ZHUH
found to be reduced, comparing to gasoline use in the 4. 8QEXUQHG HWKDQRO HQJLQHRXW HPLVVLRQV ZHUH
UHGXFHGE\LQNPK test mode at nominal
tested steady state conditions. When adapting regular
spark timing comparing to maximal brake torque
JDVROLQHYHKLFOHIRUWKHXVHRI(WKHLJQLWLRQWLPLQJ
timing.
for steady state operation can be left unchanged, at
least from the emission analysis point. The impact of The emissions of the unburned hydrocarbons,
carbon monoxide and nitrogen oxides were
the ignition timing on the output parameters of cold
UHGXFHGLQVWHDG\VWDWHWHVWFRQGLWLRQVXVLQJ(
VWDUWDQGG\QDPLFGULYLQJXVLQJ(LVDVXEMHFWIRU
fuel, comparing to the gasoline use.
future work.
The amount of acetaldehyde was increased up to
LQ WKH HQJLQHRXW HPLVVLRQV XVLQJ ( IXHO
Conclusions
when compared with the gasoline use.
1. 9ROXPHWULF VKDUH RI WKH XQEXUQHG K\GURFDUERQV
carbon monoxide and acetaldehyde emissions Ignition timing, adjusted by the test vehicle’s
manufacturer for gasoline use, was found suitable
ZDVLQVLJQL¿FDQWO\DIIHFWHGE\WKHYDULDWLRQRIWKH
IRU(IURPWKHHPLVVLRQDQDO\VHVSRLQW
ignition timing within the tested range.
2. The exhaust gas temperate increased with ignition
timing retard and was higher when the gasoline
ZDVXVHGFRPSDULQJWR(XVH
References
1. &RVWDJOLROD0$'H6LPLR/,DQQDFFRQH63UDWL09&RPEXVWLRQHI¿FLHQF\DQGHQJLQHRXW
emissions of a S.I. engine fueled with alcohol/gasoline blends. Applied EnergySS±
2. +DUD77DQRXH./DPLQDUÀDPHVSHHGRIHWKDQROQKHSWDQHLVRRFWDQHDLUPL[WXUHV$YDLODEOH
DWKWWSZZZ¿VLWDFRPHGXFDWLRQFRQJUHVVVFSDSHUVIVFSGI)HEUXDU\
+H\ZRRG-%Internal Combustion Engine Fundamentals0F*UDZ+LOO1HZ<RUNS
4. .XPDU61D\HN0.XPDU$7DQGRQ$0RQGDO3$OGHK\GHNHWRQHDQGPHWKDQHHPLVVLRQV
from motor vehicle exhaust. American Chemical Science JournalSS±
Sayin C. (2012) The impact of varying spark timing at different octane numbers on the performance and
emission characteristics in a gasoline engine. FuelSS±
Silaipillayarputhur K., Idem S.A. (2011) Spark advance effects in spark ignition engines. Journal of
Applied Global ResearcheSS±
7RSJO7<FHVX+6dLQDU&.RFD$7KHHIIHFWVRIHWKDQRO±XQOHDGHGJDVROLQHEOHQGVDQG
ignition timing on engine performance and exhaust emissions. EnergySS±
7XUQHU';X+&UDFNQHOO5)1DWDUDMDQ9&KHQ;&RPEXVWLRQSHUIRUPDQFHRIELRHWKDQRODW
various blend ratios in a gasoline direct injection engine. FuelSS±
9. 7UN|]1(UNXú%øKVDQ.DUDPDQJLO06UPHQ$$UVODQR÷OX1([SHULPHQWDOLQYHVWLJDWLRQ
RIWKHHIIHFWRI(RQHQJLQHSHUIRUPDQFHDQGHPLVVLRQVXQGHUYDULRXVLJQLWLRQWLPLQJVFuelSS
±
10. :DJQHU7:\V]\QVNL0$OGHK\GHVDQGNHWRQHVLQHQJLQHH[KDXVWHPLVVLRQV±DUHYLHZJournal
of Automobile Engineering, 210, pp. 109 – 122.
5(6($5&+)25585$/'(9(/230(1792/80(