ETHANOL INTERNATIONAL WORKSHOP 2012 - Fapesp · ETHANOL INTERNATIONAL WORKSHOP 2012 COLD START...
Transcript of ETHANOL INTERNATIONAL WORKSHOP 2012 - Fapesp · ETHANOL INTERNATIONAL WORKSHOP 2012 COLD START...
ETHANOL INTERNATIONAL WORKSHOP 2012
COLD START EMISSIONS OF
ETHANOL FUELLED VEHICLES
Prof. Luís Carlos Monteiro Sales, D.Sc
Prof. José Ricardo Sodré, Ph.D.
04/10/2012
• Introduction
• Cold start technologies
• Simultaneous heating of intake air and
injected ethanol
• Cold start time
• Cold start emissions
• Conclusions
OUTLINE
• Ethanol properties cause difficult cold start and
warm-up operation, with impacts on engine emissions
• Ethanol vaporization requires twice the energy
required by gasoline (0.744 MJ/l 0.325 MJ/l)
• Ethanol-fuelled engines do not start at temperatures
below 13°C, while gasoline-fuelled engines can start
at temperatures as low as - 40°C
• Ethanol vaporization temperature is 78°C, while the
light gasoline components can vaporize from 40°C
INTRODUCTION
PHYSICAL-CHEMICAL PROPERTIES
OF ETHANOL AND GASOLINE
PARAMETERS E22 HYDROUS ETHANOL
Density (kg/m3) 740 810
Low heating value (kcal/kg) 9400 5970
Stoichiometric air/fuel ratio 13.07 : 1 8.70 : 1
Chemical structure C6.39H13.60O0.61 C2H6.16O1.08
Carbon content (wt %) 76.7 50.59
Hydrogen content (wt %) 13.6 12.98
Oxygen content (wt %) 9.7 36.42
Evaporation temperature (ºC) 40 to 220 78
Latent heat of vaporization (kcal/kg) 105 237
Motor octane number 80 87
• Use of E85 blends
• Gasoline introduction through a calibrated hole
• Gasoline introduction through an extra fuel injector
• Gasoline introduction through an extra fuel injector
and common rail
• Ethanol heating in the fuel injectors
• Ethanol heating in the fuel injectors plus intake air
heating
• Aim at reduced cold start time and cold start
emissions
COLD START TECHNOLOGIES FOR
FLEXIBLE FUEL VEHICLES
CALIBRATED HOLE AND EXTRA FUEL
INJECTOR TECHNOLOGIES
Furo calibrado Furo Calibrado
CALIBRATED HOLE EXTRA FUEL INJECTOR
COLD START TIME FOR
DIFFERENT CONFIGURATIONS
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
TEMPO (s)
0
250
500
750
1000
1250
1500
1750
2000V
EL
OC
IDA
DE
(re
v/m
in)
CONFIGURAÇÃO 1CONFIGURAÇÃO 2CONFIGURAÇÃO 3CONFIGURAÇÃO 4
EXTRA FUEL INJECTOR WITH
COMMON RAIL TECHNOLOGY
• 950 W electric resistance required to
heat ethanol in four injectors
• Cold start below 5C between 2.0 s
and 4.0 s
• Cold start time for intake air heating
only using 600 W electric resistance
between 10 s and 27 s
ETHANOL HEATING IN THE FUEL
INJECTORS
ETHANOL JET FLOW
CHARACTERISTICS
NO HEATING HEATED INJECTOR
TOTAL HYDROCARBON AND
CARBON MONOXIDE EMISSIONS
Tempo (s)
TH
C a
cu
mu
lad
o(g
)
sem aquecimento
antes do catalisador
velocidade
no ciclo
com aquecimento
antes do catalisador
sem aquecimento
depois do catalisador
com aquecimento
depois do catalisador
Tempo (s)
TH
C a
cu
mu
lad
o(g
)
sem aquecimento
antes do catalisador
velocidade
no ciclo
com aquecimento
antes do catalisador
sem aquecimento
depois do catalisador
com aquecimento
depois do catalisador
Tempo (s)
CO
ac
um
ula
do
(g)
sem aquecimento
antes do catalisador
velocidade
no ciclo
com aquecimento
antes do catalisador
sem aquecimento
depois do catalisador
com aquecimento
depois do catalisador
Tempo (s)
CO
ac
um
ula
do
(g)
sem aquecimento
antes do catalisador
velocidade
no ciclo
com aquecimento
antes do catalisador
sem aquecimento
depois do catalisador
com aquecimento
depois do catalisador
• Catalytic converter efficiency is low during the
first 55 s after cold start
• During this period HC and CO concentrations
account for about 40% and 30% of the total
amount during FTP-75 emission test schedule
• Aldehyde emissions are about 70% of the total
amount during emission test cycle
• NOX emissions during cold start is very low
CHARACTERISTICS OF POLLUTANT
EMISSIONS DURING COLD START
SIMULTANEOUS HEATING OF ETHANOL
INJECTORS AND INTAKE AIR
• Production vehicle powered by a 1.4-liter, 8-
valve, flex fuel engine operating with hydrous
ethanol
• Cold start tests at 0ºC
• Emission tests following FTP-75 cycle at 25ºC
• Simultaneous heating of ethanol injectors and
intake air activated 8.0 s before cold start
• Ethanol injection pressure 3.5 bar
EXPERIMENTAL METHODOLOGY
COLD START TIME AT 0C
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
TIME (s)
0
250
500
750
1000
1250
1500
1750
2000
2250E
NG
INE
SP
EE
D (
rev/m
in)
-10
0
10
20
30
40
50
60
70
80
TE
MP
ER
AT
UR
E (
oC)
MIXTURE TEMPERATURE AT INTAKE PORTETHANOL TEMPERATURE AT INJECTORAIR TEMPERATURE AFTER HEATERENGINE SPEED
TIME-RESOLVED RELATIVE
HYDROCARBON EMISSIONS
0 100 200 300 400 500
TIME (s)
0.00
0.03
0.06
0.09
0.12
0.15
0.18
0.21IN
ST
AN
TA
NE
OU
S H
C/T
OT
AL
HC
(%
) HEATED INTAKE AIR AND ETHANOLCONVENTIONAL COLD START SYSTEM
TIME-RESOLVED RELATIVE
CARBON MONOXIDE EMISSIONS
0 100 200 300 400 500
TIME (s)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90IN
ST
AN
TA
NE
OU
S C
O/T
OT
AL
CO
(%
) HEATED INTAKE AIR AND ETHANOLCONVENTIONAL COLD START SYSTEM
TIME-RESOLVED RELATIVE OXIDES
OF NITROGEN EMISSIONS
0 100 200 300 400 500
TIME (s)
0.000
0.020
0.040
0.060
0.080
0.100IN
ST
AN
TA
NE
OU
S N
OX/T
OT
AL
NO
X (
%)
HEATED INTAKE AIR AND ETHANOLCONVENTIONAL COLD START SYSTEM
RAW EXHAUST HC, CO AND NOX
EMISSIONS AFTER COLD START
THC CO NOX
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0C
ON
CE
NT
RA
TIO
N (
g/k
m)
HEATED INTAKE AIR AND ETHANOLCONVENTIONAL COLD START SYSTEMRAW EMISSIONS, COLD 505
POST-CATALYST EXHAUST HC, CO, NOX AND
CHO EMISSIONS AFTER COLD START
HC CO NOX CHO
0.00
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00C
ON
CE
NT
RA
TIO
N (
g/k
m)
HEATED INTAKE AIR AND ETHANOLCONVENTIONAL COLD START SYSTEMPOST-CATALYTIC CONVERTER, COLD 505
POST-CATALYST EXHAUST HC, CO, NOX
AND CHO EMISSIONS FOR FULL CYCLE
THC CO NOX CHO
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
CO
NC
EN
TR
AT
ION
(g
/km
)
HEATED INTAKE AIR AND ETHANOLCONVENTIONAL COLD START SYSTEMPOST-CATALYTIC CONVERTER, FULL FTP-75 CYCLE
• The use of 300 W electric resistance to heat the intake air together
with 150 W electric resistances to heat ethanol injectors allowed for
satisfactory cold start time
• At 0°C the cold start time defined by the period from ignition key
switch until the engine reached 800 rev/min was 1.7 s, which is 15%
below acceptable standards
• Simultaneous ethanol and intake air heating produced significant
reductions on raw exhaust HC and CO emissions, especially in the
first 150 s of the U.S. FTP-75 test schedule
• Catalytic converter efficiency for HC and CO reduction was also
increased with heated intake air and ethanol
• NOX and aldehyde emissions were not significantly altered by the
new cold start system
CONCLUSIONS
ACKNOWLEDGMENTS