Sources of CO and UHC Emissions in Low-Temperature Diesel Combustion Systems Sandia National Laboratories C R F Dae Choi, Will Colban, Isaac Ekoto Duksang Kim, Sanghoon Kook Paul Miles, Seungmook Oh Michael Andrie, Dave Foster, Chad Koci Roger Krieger, Rick Opat, Sung Wook Park Youngchul Ra, Rolf Reitz University of Wisconsin ERC Russ Durrett, Manuel Gonzalez John Pinson, Bob Siewert General Motors R&D Work supported by: US DOE Ofce of Vehicle Technologies Gurpreet Singh, Program Manager General Motors Corporation GM-UW CRL & SNL Agreement FI083070326 DEER 2008, August 4-7, Dearborn, Michigan
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Sources of CO and UHC Emissions in Low-Temperature Diesel … · Sources of CO and UHC Emissions in Low-Temperature Diesel Combustion Systems Sandia National Laboratories CR F Dae
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Sources of CO and UHC Emissions in Low-Temperature Diesel Combustion Systems
Sandia National Laboratories CRF
Dae Choi, Will Colban, Isaac Ekoto
Duksang Kim, Sanghoon Kook
Paul Miles, Seungmook Oh
Michael Andrie, Dave Foster, Chad Koci
Roger Krieger, Rick Opat, Sung Wook Park
Youngchul Ra, Rolf Reitz
University of Wisconsin ERC
Russ Durrett, Manuel Gonzalez
John Pinson, Bob Siewer t General Motors R&D
Work supported by: US DOE Office of Vehicle Technologies
Gurpreet Singh, Program Manager
General Motors Corporation
GM-UW CRL & SNL Agreement FI083070326
DEER 2008, August 4-7, Dearborn, Michigan
We focus on early-injection, PCI-like combustion systems
Toyota
"smokeless”
combustion
(SAE 2001-01-0655)
AVL HCLI systems
(MTZ, Sept 2003)
16
14
12
10
8
6
4
2
0 1000 1500 2000 2500 3000 3500
Speed [RPM]
Load
[bar
]
Conventional Diesel Combustion
HPLI, Highly Premixed Late Injection
HCLI, Homogeneous Charge Late Injection
HPLI
HCLI
Injec ion Heat Release
Heat Release Injection
TDC
Low-temperature combustion
systems are attractive because:
t -PX /0x and PM emissions are
obtained simultaneously
t 5IFZ FNQMPZ Ucombustion sy
ZQJDBM EJFTFMstem FIE & Bo
wl
geometry
t $PNCVTUJPO UJNJOH JT DCZ UIF JOKFDUJPO FWFOU
POUSPMMFE
However:
t 5IFZIJHI $
PGUFO TVòFS GS PN B GVFM FDPOPNZ QFOBMUZ BTTPDJBUFE XJUI
0 BOE 6)$ FNJTTJPOT
t 5IFZ BSF BQQMJDBCMF P WFS POMZ B MJNJUFE TQFFE�MPBE S BOHF
CO and UHC emissions can stem from cool, fuel-lean regions as well as fuel rich regions
Constant φ & T, P = 60 bar, Δt=2 ms, 21% O 2 Soot/NOx contours from Kitamura, et al., JER 3, 2002
4
CCO 15% Soot 10%
5%
1%
500 ppm
NTC region
88 g/kgfuel
NOx
5000 ppm
10002
3
Equ
ival
ence
Rat
io
CO [g / kg-fuel ]
1500
500
1
0
0600 1000 1400 1800 2200 2600
Temperature [K]
4
UHC 15%
10%
Soot
5%
1%
500 ppm
NTC regi 20on g/kg-fuel
NOx
5000 ppm
100
10
3
2
1Equ
ival
ence
Rat
io
0600 1000 1400 1800 2200 2600
Temperature [K]
UH
C [ g / kg-fuel ]
1000
1
t -PX 6)$ DBO S FTVMU FWFO GS PN P WFS�SJDI S FHJPOT
t 'PS MFBO NJYUVSFT U FNQFSBUVSFT BCPWF ���� , ���� , XJMM GVMMZ P YJEJ[F $ 0 6)$
t 6)$ BMTP TUFNT GS PN D PPM 5 � ��� , S FHJPOT B U BMM FRVJWBMFODF S BUJPT
How will EGR influence the kinetics of CO and UHC oxidation?
CO @ constant φ & T, P = 60 bar , Δt=2 ms 4
2200 2600
15%
10%
5%
1%
Soot
500 ppm
5000 ppm
NOx
10% O2
15% O2
21% O2
3
2
1
0 600 1000 1400 1800
Temperature [K]
EGR hardly impacts CO
yield from constant T, P
simulations
CO emissions impacted
only in low
temperature crevice
regions
E
qu v
a en
ce R
at o
The isothermal constraint prevents heat
release from raising the temperature and
increasing the heat release rate
An adiabatic treatment (with pressure
matched to experiment) is more repre
sentative of regions away from walls
2000
1800
21% O2
15% O2
10% O2
21% O2
15% O2
10% O2
88 g/kg-fuel
CO oxidation
threshold
UHC oxidation
threshold
20 g/kg-fuel
1600
1400
1200
UH
C_
EI
[g/k
g-f
ue
l]
CO
_E
I [
g/k
g-f
ue
l]
T
[K
] m
ax
1200
1000
800
600
400
200
0
250
200
150
100
50
0 0 0.1 0.2 0.3 0.4 0.5 0.6
Equivalence Ratio φ
t 5 IF QFBL U FNQFSBUVSF OFFEFE U P P YJEJ[FUHC & CO is independent of dilution
t %JMVUJPO TJHOJöDBOUMZ JODSFBTFT UIF FRVJWBlence ratio needed to reach this temperature
Engine & experiment
Intake
Lasersheet
Exhaust
Line-imaging FOV
PLIF-imaging FOV
Removeable Mirror Laser
sheetICCD Filter
������ON ��ON�'8).�
PI MAX ICCD
t������CZ�����SFTPMVUJPO
t�����OT�HBUF
Princeton Instruments
ICCD-576E
t������CZ����
t�����OT�HBUF
Mirror
Collection lens
SPEX 270M Spectrometer
t������UP�����ON�#1
t����ON�SFTPMVUJPO
Bosch CRI2.2 Common Rail FIE
/P[[MF� ��IPMF �����¡ ������<DN�������T>
3BJM�1SFTTVSF� ����CBS
'VFM� 64����EJFTFM�GVFM
GM 1.9l cylinder head
#PSF� �����NN4USPLF� �����NN(FPNFUSJD�$3� ����
&òFDUJWF�$3� ����
Optical piston retains
prototype GM
designed bowl
2-d PLIF Images:
1-d, spectrally-resolved: 30°CA
1 1.5 bar
0.8 CO
3.0 bar 0.6
0.4
0.2 4.5 bar
0
Radius [mm] 0 5 10 15 20 25 30 35 40
Nor
mal
ized
CO
[ - ]
Experimental PLIF images are corrected for distortion and laser sheet inhomogeneity
Clearance volume reference grid
Back-lit bowl reference grid
Before correction
Reference grid images in both the clearance volume