Status Update on Ducted Fuel Injection - Sandia National ...
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SAND2020-6379PE
Status Update on Ducted Fuel Injection
Charles J. Mueller, Christopher W. Nilsen,
Drummond E. Biles, & Boni F. Yraguen
Sandia National Laboratories, Livermore, California
Research supported by: U.S. Dept. of Energy, Vehicle Technologies Office
Program managers: Kevin Stork, Michael Weismiller, & Gurpreet Singh
Co-Optima Mini-Symposium: MCCI Fuels
Online
Sandia National Laboratories is a multimission laboratory managedJune 23,
and operated 2020
by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned
subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
Objective: Maintain all the desirable attributes
of conventional diesel combustion (CDC)...
practical 0 02
high
cost
effective
clean secure
easy to 0.0 5
thermal control ign.
eff'ncy Typical soot/NOx
timing
•• trade-off curve for
low
HC & CO
• high
power ut 001
CDC
emiss'ns
• • density +1
o
•• •
low cyclic durable & 0 005 •
•
variability reliable
fuel
flexible
• 2 4 6
N Ox [gilk1APh]
...with 10X 100X lower soot & nitrogen oxides(NOx)emissions
...while harnessing synergies with sustainable, home-grown fuels.
Fig.6.
Ducted fuel injection (DFI)shows
promise for achieving this vision.
• DFI is a simple, mechanical approach to
improving diesel combustion Bunsen and Roscoe,
— Motivated by Bunsen burner concept Phil. Trans. Royal Soc.
London 147:355-380,
1857.
Ducted fuel injection (DFI)shows Basic idea: inject the fuel spray
promise for achieving this visior down a small tube aligned
with the spray axis
• DFI is a simple, mechanical approach for
improving diesel combustion
Fuel-injector tip
— Motivated by Bunsen burner concept
Duct
— A refinement of CDC —> behaves similarly
• Recent engine exp'ts have shown DFI:
1. Is effective at curtailing/eliminating soot
2. Can break the soot/NOx trade-off with dilution
3. Is synergistic with dilution for emis'ns & effic'cy Liquid fuel
4. Is both compatible with current diesel fuel & Vapor-fuel/charge-gas mixture
synergistic with oxygenated sustainable fuels Autoignition zone
5. Is easy to control 1 / Products of rich combustion
6. Performs well across a range of loads — Diffusion flame
Thermal NO production zone
7. Outperforms CDC under cold-start conditions
Mueller et al., doi:10.1016/j.apenergy.2017.07.001
1. DFI dramatically curtails
soot production in engine
experiments.
CDC i DFI
Duct
Little to
no soot
\LFuel-injector tip Piston bowl rim
Liquid fuel
Vapor-fuel/charge-gas mixture
Autoignition zone
• Soot and soot precursors
Diffusion flame S. Ashley, https://www.scientificamerican.com/
Thermal NO production zone article/can-diesel-finally-come-clean/
2. With DFI, NOx can be controlled via dilution without
excessive soot, breaking the soot/NOx trade-off.
0.1
O 21 mol% 02
Soot/NOx trade-off curve for O 18
0.08
conventional diesel combustion O 16 DFI
O 14 data
0.06 O 12
Current
8 0.04 US EPA
cr)
on-road
limits
0.02
/ Dilution
■
10-1 10° 10'
NO3([g/kWh]
riP
3. DFI is synergistic with dilution.
X02
• DFI shows generally lower emissions & higher CDC Ei 12%
— El 14%
efficiencies vs. CDC as dilution T. DFI has: — III 16%
iii 18%
— Lower soot, HC, & CO emiss. at const. X02 16% CI 21%
— Lower NOx at minimum feasible X02 level _
—nim,J lin.. lii ..I
— Higher fuel-conversion efficiency as X02 level '
,1--4-(/),:r cr)
-'1.00C‘i
r- pa,Co c.o
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. r•-:c.1,-.-6 ci,- ,-ci
cid,-olo c`l c'00 -C‘Ortc0 00000f .7.7;7.7.7
_ .- 00000
X02 = intake-oxygen
mole fraction 1=1
DFI
lit = fuel-conversion
efficiency
Four-duct config., DFI relative to CDC ,_,TH rirmii _will
1200 rpm, Tr.00.
'0. 1". co. .L0
0(.0.1- cn,-
cs1-701.3)
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0000
ai oivr ci?Lo't~ ri
OTO nN
c‘i • • dd.-cod Qqci'cl0 ocspicsicti oodOci 77444-
—6.7 bar IMEPg ruirnrncd TT'? r"..- sf?sPcifF.`0.51 c?()iv? '
9c?' R2 -
.- 00000
vvvvv -
ANO1 Moot AESINL ANC ACO NOIL SmA ESN_ HIC CO Mr
rig rA] nrei LOW
4. DFI is synergistic with oxygenated renewable fuels,
lowering SINL by another 10X relative to petro-diesel.
SINL = spatially
1 integrated natural
\1\-CFB luminosity, a measure
of hot, in-cylinder soot
CDC CFB = No. 2 diesel
DFI OM. 1•Min
fuel MD25 = 25 vol%
effect biodiesel surrogate
MD25
T25 = 25 vol% tri-
T25 propylene glycol mono-
methyl ether
DFI
0 15 30 45 0 15 30
Crank Angle[deg ATDC] Crank Angle[deg ATDC]
• Changing from CDC to DFI lowers SINL more than adding 25 vol% of either oxy.
• Fuel effect is larger for DFI than for CDC(on a percentage basis)
5. DFI is easy to control; its heat release is similar to CDC.
DOli = indicated
120 DFI - (i.e., commanded)
duration of infn
Four-duct config.,
1200 rpm,
2.4 - 8.7 bar IMEPg
I MEPg = gross
20 indicated
0 mean effective
pressure
0 15 30 45 0 15 30 45
Crank Angle [deg] Cr nk Angle[deg]
• Ignition timing & load are easily controlled by changing injection timing
• DFI has larger premixed burns & shorter combustion durations than CDC
6. DFI performs well across a range of loads.
• Soot is 50 - 90% Nie for DFI across the sweep CDC
_
• NOx is 2 - 11% T & 74 is 0.3 — 3.0% le for DFI
— Both can be improved via dilution
• HC & CO are lower for DFI when DOI; is longer
• DFI performance generally T with longer DOI;
..,...1 1111 :611
- 0, x. cu
c2 _ ,_
,_ q CD
_.
Tr Tr o) CD
0000 C' CD
01 CC! 111 1.11
C) 03 C.0 03
T- .- CV CV
II li.
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0006
C
)'''
7 c0 h co
CO ,- .,. 1
.
nim
h c,-)r-. N:
(
69? ;7.
66 e57. DFI outperforms CDC at simulated cold-start cond's.
• Emissions & efficiency. DFI has:
— Lower soot, HC, & lower/similar CO
— Lower NO), at min. intake-manifold temp.(IMT
— Similar rif vs. CDC
• DFI should work well for cold-starts & at
cond's below catalyst light-off temp.
I
CDC
N. CD
Ii
71- N CO
. 0
DFI
. o o o
000
II
Cr) CO O LO
CO CO
CV CV
I MT
CO 0
00
LO v CO
o
CO CV
1 •71- •71-
1I
Four-duct config., • 50° C
0 70° C
1200 rpm 0 90° C
6.7 — 7.0 bar IMEPg
16% X02 DFI relative to CDC
C
CO CY) 71- C N 0 LO 0 -71-
71- OD 0 CO G) 0 ui co 0)
. 0) 0
0
00
O o
CO N N
CO G) cr) O 4 4 co. c 0 CD
o o
O O O 71-
r- r- 9 9 9
v v v
ANO. ASoot AXSINL AHC ACO ATI NO1 Soot ).:S1NL HC CO /If
[%1 [%] [%] [%} rA1 WkWit] [gfM] [a.u.] [gfkINh] [g/kwh] [%]Low
Summary & conclusion Cost
• Ducted fuel injection (DFI):
— Is conceptually simple Technically Secure
DFI
— Is effective at curtailing/eliminating soot Viable
— Can break the soot/NOx trade-off with dilution
— Has improved emissions & efficiency with dilution
— Is fully compatible with conventional diesel fuel
Clean
— Is synergistic with oxygenated sustainable fuels
— Is easy to control & performs well across a range of loads
— Outperforms CDC under cold-start conditions
DFI with oxygenated, sustainable fuels provides a promising potential path to
practical, clean, & sustainable vehicles & machines for the future.Next steps
o o o
• FY20
— Blends of butylal & hexyl hexanoate in commercial base diesel fuel
► Ignition-delay effects
► Molecular-structure effects
► Oxygen-content effects (25 vol%)
• FY21
— Blends of hydroxyalkanoate ether ester (HEE) in two base fuels
► Effect of changing base diesel fuel from commercial diesel to HTL/ETD
o Commercial diesel fuel
o 70 vol% high-temperature liquefaction (HTL) diesel + 30 vol% ethanol-to-diesel (mixture of
branched alkanes, to prevent fuel solidification at high rail pressures)
► CDC vs. DFI effects
► Oxygen-content effects (25, 50, 75 vol% HEE in HTL/ETD)ra Additional information on Sandia DFI research • 1st paper in Applied Energy: https://www.sciencedirect.com/science/article/pii/S0306261917308644 • 2nd paper in Applied Energy: https://www.sciencedirect.com/science/article/pii/S0306261918307888 • 1st results from DFI engine experiments: https://saemobilus.sae.org/content/03-12-03-0021/ • YouTube video for R&D 100 Special Recognition Silver Medal in "Green Tech": https://youtu.be/ldijtRUZeLw • Scientific American article: https://www.scientificamerican.com/article/can-diesel-finally-come-clean/ • 2nd results from DFI engine experiments: https://saemobilus.sae.org/content/03-13-03-0023/
fuel inj
DFI experiments have been vahre sort
cylinder head
conducted using one-, two-,
& four-duct configurations.
metal
cylinder
liner
• Key duct parameters D2L12G36
— Inner diameter(D [mm])
ightfrom
— Length (L[mm]) combustion
chamber
— Standoff distance (G [mm])
— Inlet/outlet shape (Greek letter)EP
DFI is viable over a range of operating conditions with
conventional diesel fuel.
Engine speed 1200 rpm
Load (gross IMEP) 2.4 — 8.7 bar
Fuel No. 2 S15 cert. diesel
Injector tip 4 x 0.108 mm x 140°
Injection pressure 80, 180, 240 MPa
Intake-02 mole fraction 12, 14, 16, 18, 21%
lnj. duration (commanded) 1.5, 2.5, 3.5, 4.5 ms
4D2L12G35 duct configuration
Start of combustion timing -5.0, +5.0 CAD ATDC
Intake manifold abs. press. 2.0, 2.5, 3.0 bar
Roughly corresponding to:
Intake manifold temperature 50, 70,90 °C
• 1.3, 1.6, 2.0 bar
Coolant temperature 50, 70,90 °C
• 13, 31, 49 °C
Fired cycles per run 180
in a metal engine with 17:1 CR
Runs per condition >3You can also read
