Efficiency-Optimized Dual Fuel Engine with in-cylinder … · we start with yes. efficiency-optimized dual fuel engine with in-cylinder gasoline/cng blending thomas wallner riccardo

WE START WITH YES.

EFFICIENCY-OPTIMIZED DUAL FUEL ENGINE WITH IN-CYLINDER GASOLINE/CNG BLENDING

THOMAS WALLNERRICCARDO SCARCELLI

JAMES SEVIKMICHAEL PAMMINGER

CHRIS POWELLArgonne National Laboratory

RONALD A. REESE, IIASIM IQBALFCA US LLC

STEVE WOOLDRIDGEBRAD BOYER

Ford Motor Company

June 9, 2016

This presentation does not contain any proprietary, confidential, or otherwise restricted information

Project ID: FT046 DOE Sponsor: Kevin Stork

ACKNOWLEDGEMENT OF FEDERAL SUPPORT AND DISCLAIMER

Acknowledgment: “This research is funded by DOE's Vehicle Technologies Program, Office of Energy Efficiency and Renewable Energy through an award based on the FY 2014 Vehicle Technologies Program Wide Funding Opportunity Announcement DE-FOA-0000991 (0991-1822).”Disclaimer: “This presentation was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express of implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government of any agency thereof.”

Critical Assumptions and Issues

2

OVERVIEW

Budget Total project funding

DOE: $1M 20% in-kind cost share

Funding in FY15: $512k Funding in FY16: $320k Funding in FY17: $168k

Timeline Project start: October 2014 Project end: March 2017 Percent complete: 50%

Barriers Limited NG infrastructure and

refueling station availability currently presents one of the main barriers to large-scale introduction of CNG in light-duty (LD) applications.

Existing data and models for engine efficiency, emissions, and performance based on fuel properties and fuel-enabled engine designs or operating strategies are inadequate.

Partners FCA US LLC Ford Motor Company

Approach Accomplishments Collaboration Future workRelevance

3

RELEVANCE DOE ARPA-e MOVE is working towards aggressive goals for natural gas

at-home-refueling and on-board storage Today’s NG vehicles have lower fuel economy (FE) compared to gasoline

counterparts despite the higher knock resistance of natural gas Bi-fuel vehicles use natural gas until depleted and then switch to gasoline

thereby leaving overall fuel consumption reduction potential untapped


ARPA-e MOVE program goals*

*ARPA-e MOVE program overview. 2012.

0

10

20

30

40

50

60

UDDSCold Start

UDDSHot Start

HWFET US06 US06City

US06Highway

Fuel

eco

nom

y [m

pge,

mpg

]

Civic Gasoline [mpg] Civic Natural Gas [mpge]

*Anderson, J., et al., ‘Performance and Efficiency Assessment of a Production CNG Vehicle Compared to Its Gasoline Counterpart,’

SAE Paper 2014-01-2694, 2014, doi:10.4271/2014-01-2694.

Gasoline/NG Vehicle FE Comparison *

4

PROJECT OBJECTIVES

What? Demonstrate the benefits of natural gas direct injection and targeted in-

cylinder gasoline/CNG blending on engine efficiency and performance Develop vehicle level blending strategies to maximize attainable fuel

economy benefits adhering to limited on-board NG supply constraints Why?

Reduce petroleum consumption of light-duty spark-ignition engine vehicles by at least 50%

How? Petroleum displacement Relative engine efficiency improvement in excess of 10% Retrofitability requirements Anticipated payback period of less than 36 months 10% improvement in power density over the PFI baseline


5

MILESTONES AND DECISION POINTSMonth/Year Description Status

Dec 2014 NG DI Hardware available for integration on research engine Completed

March 2015 Injector gas jet characteristics validated against X-ray data Completed

June 2015 Baseline maps established with neat fuels Completed

Sept 2015 Baseline maps established in blended operation Completed

Sept 2015 Predictive engine simulation validated against experimental data Completed

Sept 2015 Successful demonstration of potential of blended approach Completed

Dec 2015 Design criteria and development targets quantified Completed

March 2016 Hardware freeze for optimized combustion system design Completed

June 2016 Optimized hardware available for implementation

Sept 2016 Performance established with optimized configuration

Sept 2016 Efficiency improvement of optimized system demonstrated

Dec 2016 Vehicle level control strategy identified

March 2017 Demonstrate FOA Project Goals


6

Task Partner Duration 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

1 6

1.1 Chrysler 3

1.2 Argonne 2

1.3 Argonne 6

2 12

2.1 Ford 4

2.2 Argonne 2

2.3 Argonne 3

2.4 Argonne 3

2.5 Argonne 6

3 6

3.1 All 3

3.2 Argonne 6

3.3 All 3

4 6

4.1 Ford 3

4.2 Argonne 3

5 6

5.1 All 3

5.2 All 3

Deliverable Milestone Go/No-Go Decision FOA Goal Demonstration

Phase I Phase II Phase III

Procure/provide NG DI hardware

Characterize CNG jets using Argonne's X-ray diagnostics

Title

Characterization of NG DI injector

Simulate mixture formation and combustion process

Determine evaluation criteria/development targetsPerform simulations to determine optimized engine configuration

Evaluate design options/feasibility

Perform 3D-CFD simulations to validate gaseous jet characteristics

Design/modify cylinder head to accommodate NG DI hardwareImplement NG DI hardware on single-cylinder engine

Develop baseline engine maps (gasoline, CNG)

Develop baseline engine maps (blended operation)

Evaluation of experimental baseline and concept potential

Virtual combustion system optimization

Experimental validation of optimized combustion system

Vehicle level analysis and cost assessment

Perform engine tests on optimized hardware

Develop vehicle level strategy/estimate vehicle level potential

Perform cost analysis

Design/build optimized engine hardware

APPROACHApproach Accomplishments Collaboration Future workRelevance

Characterize NG DI jets using x-ray diagnostics to validate CFD simulations Determine validity of the

proposed concept experimentally

Develop optimized design to maximize

concept benefits

Evaluate optimized configuration and

generate efficiency mapsDetermine vehicle level control strategy and fuel

economy potential

7

X-RAY INJECTOR GAS JET MEASUREMENTS

8

)--".&%3( )%%.,-'#*3,2/4*( !.''&5."&$./( 6+4+"2(7."8(92'2:&/%2(

!! Outward opening NG injector !! Pressure ratios typical for engine

operation (injector rated at 16 bar) !! Evaluate cases with wall

interaction (engine experiments include central and side NG injector location)

Pressure, bar(Condition( Injection

Argon$Ambient Nitrogen$

Energizing time [ms]$ Barrier$

1( 10$ 1$ 2$ No$2( 15$ 1$ 2$ No$3( 10$ 2$ 2$ No$

1-B( 10$ 1$ 2$ Yes$2-B( 15$ 1$ 2$ Yes$

INJECTOR GAS JET SIMULATION VALIDATIONApproach Accomplishments Collaboration Future workRelevance

Successfully validated CFD simulations against X-ray data for free jets as well as impinging jets at several pressure ratios

Developed best practice (grid resolution, boundary conditions) to achieve good agreement while limiting computational time

Current minimum mesh size in engine simulations is 125µm

9

EXPERIMENTAL SETUPApproach Accomplishments Collaboration Future workRelevance

Single-cylinder research engineDisplacement L 0.6264Stroke mm 100.6Bore mm 89.04Compression ratio - 10.5:1Valve configuration - 4, 40° Pent RoofSpark plug - NGK, 0.7 mm gapTumble ratio - 0.6

Experimental matrixEngine speed rpm 1500, 2000, 2500IMEP (net) bar 3.2, 5.6, 8.0, WOTSOI DI °CA BTDC Sweep, 120-360SOI PFI °CA BTDC Sweep, 150-630

10

BASELINE MAPS WITH NEAT FUELSApproach Accomplishments Collaboration Future workRelevance

Retarded ignition starting at 8 bar IMEP reduces ITE for E10 PFI (only 33.2% ITE at WOT and 1500 rpm)

NG DI shows high ITE (39.1%) at WOT and 1500 rpm due to efficient combustion phasing

Highly efficient WOT operation with NG DI compared to E10 PFI results in 18%relative increase in ITE

Result is beyond project target of 10% higher efficiency for NG DI

High efficiency operation and direct injection allow increased WOT performance resulting in 1.3 bar (12%) higher IMEP with NG DI compared to E10 PFI

NG DI (side)E10 PFI

Efficiency difference

12%

11

SUCCESSFUL DEMONSTRATION OF POTENTIAL OF BLENDED APPROACH

12

)--".&%3( )%%.,-'#*3,2/4*( !.''&5."&$./( 6+4+"2(7."8(92'2:&/%2(

!! Induced turbulence due to direct injection is capable of extending EGR dilution tolerance

!! Best performance shown by fueling the engine with 25% NG !! 25% NG shows 0.5% higher

ITE compared to E10 PFI !! 6% higher EGR dilution

tolerance for 25% NG compared to E10 PFI by maintaining 3% COVIMEP

!EGR=6%

0.5%

SUCCESSFUL DEMONSTRATION OF POTENTIAL OF BLENDED APPROACH


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40

9

10

11

-540 -360 -330 -300 -270 -240 -210 -180 -150 -120 -90

1

2

3

4

50

10

20

30

40

ITE

[%]

E10 PFI 25% NG 50% NG 75% NG NG DI

IMEP

[bar

] C

OV IM

EP [%

]

SOI [°aTDC]

0.0

0.1

0.2

0.3

0.4 Exhaust Valve Event Intake Valve Event

AI 50

[°C

A]

E10 and 25% NG require retarded ignition in order to avoid knocking

No knock mitigating measures when engine is fueled with 50% NG (or more)

WOT performance can be significantly increased when NG is injected after (or at) IVC

Highest IMEP (more than 11bar) can be achieved using 50% NG in its current configuration (CR=10.5)

13

PREDICTIVE ENGINE SIMULATION VALIDATED AGAINST EXPERIMENTAL DATA


Predicted effect of DI injection timing on mixture homogeneity and efficiency Correlated DI location effect on turbulence (TKE) with measured Flame

Development Angle (FDA) and Combustion Duration Provided insight for the optimization of in-cylinder mixing and turbulence

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35

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40

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3

5

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360 330 300 270 240 210 180 150 120 Com

bust

ion

Dur

atio

n [°

CA

]

Flam

e D

evel

opm

ent A

ngle

[°C

A]

SOI [°CA BTDC]

CentralSide

1500 rpm5.6 bar IMEPMBT Timing

TKE (CFD) and Comb Duration

Largest difference between center and side is at SOI 240

14

0

50

100

150

200

250

300

-300 -270 -240 -210 -180 -150 -120 -90 -60 -30

TKE

[m2 /s

2 ]

Crank Angle [°CA]

Side injection (outward opening)Central injection (outward opening)

SOI120

SOI240

SOI120

SOI300

SOI300

SOI240

1500 RPM5.6 bar IMEP

0

5

10

15

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25

30

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50

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

Volu

me

Frac

tion

[%]

Equivalence Ratio, ɸ

Side injection (outward opening)Central injection (outward opening)

SOI300

SOI240

SOI120

SOI120

SOI240

SOI300

1500 RPM5.6 bar IMEP25°CA BTDC

DESIGN CRITERIA AND DEVELOPMENT TARGETSApproach Accomplishments Collaboration Future workRelevance

Derive quantifiable metrics from 3D-CFD mixture formation simulations Trade-off: Maximize mixture homogeneity while maintaining high levels of

(injection-induced) charge motion

Fully homogenous air/fuel mixture desirable for complete combustion

Increased turbulent kinetic energy desirable

for faster combustion

15

0

50

100

150

200

250

300

-300 -270 -240 -210 -180 -150 -120 -90 -60 -30

TKE

[m2 /s

2 ]

Crank Angle [°CA]

Side injection (outward opening)Central injection (outward opening)Central injection, multi-hole (3h-45deg)Central injection, multi-hole (3h-60deg)


0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

-50 -45 -40 -35 -30 -25

ɸSt

anda

rd D

evia

tion

[-]

Crank Angle [°CA]

Side injection (outward opening)Central injection (outward opening)Central injection, multi-hole (3h-45deg)Central injection, multi-hole (3h-60deg)

SOI120

SOI300 SOI240

SOI300SOI240

SOI120

SOI300

SOI240

SOI120SOI120

SOI240

SOI300


ANALYSIS OF DESIGN PARAMETERSApproach Accomplishments Collaboration Future workRelevance

Injector design and location Central vs. side, outward opening vs. multi-hole

Intake design Influence of charge motion

Compression ratioGood homogeneity with

multi-hole nozzles despite late injection

Multi-hole nozzles and late injection increase

turbulent kinetic energy

16

HARDWARE FREEZE FOR OPTIMIZED COMBUSTION SYSTEM DESIGN


Increase compression ratio from 10.5:1 baseline to 12.5:1 and 14.5:1 Increase tumble ratio from 0.6 to 1.5 for improved dilution tolerance Focus on side NG DI location for outward opening injector Evaluate inward opening injector concept in central NG DI location

0

10

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60

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90

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110

120

130

-140 -120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120 140

Cylin

der P

ress

ure

[bar

]

Crank Angle [°CA]

CR16.6

CR15.5

CR14.5

CR13.5

CR12.5

CR11.5

CR10.5

Ppeak threshold

NG DI SideSpeed = 2500rpmIntake pressure = 14.5psiCylinder Mass, WHT modeland Combustion Duration constant for all CR's(taken from the CR 10.5 measurements)

17

RESPONSE TO REVIEWER COMMENTS

This project is a new start and has not previously been reviewed at an Annual Merit Review


18

COLLABORATION AND COORDINATION Jointly proposed project in response to FY 2014 Vehicle Technologies

Program Wide Funding Opportunity Announcement (DE-FOA-0000991)


Injection hardware Technical guidance

Engine hardware Technical guidance

Engine experiments CFD simulations

Bi-weekly conference callsSeveral in-person meetings

Quarterly progress reports to DOEJoint publications

19

REMAINING CHALLENGES AND BARRIERS

Identify main operational parameters (injection strategy incl. timing and number of pulses) for optimized engine configuration (compression ratio, in-cylinder flow, injector configuration) that yield maximum benefits

Derive approach to predict minimum NG level in the fuel blend to avoid knocking combustion as a function of speed, load and compression ratio

Design, build and evaluate optimized configuration adhering to project and technical boundary conditions

Translate single-cylinder engine results into vehicle level fuel economy data and establish vehicle level in-cylinder gasoline/CNG blending strategy to maximize fuel economy benefits

Estimate vehicle level fuel economy gains compared to baseline cases Perform cost assessment and payback calculations


20

PROPOSED FUTURE WORK

Complete experimental evaluation of in-cylinder blending concept with optimized configuration

Design vehicle level control strategy targeting maximum overall efficiency while adhering to project goals and limitations


3 6

3.1 All 3

3.2 Argonne 6

3.3 All 3

4 6

4.1 Ford 3

4.2 Argonne 3

5 6

5.1 All 3

5.2 All 3

Deliverable Milestone Go/No-Go Decision FOA Goal Demonstration

p

Determine evaluation criteria/development targetsPerform simulations to determine optimized engine configuration

Evaluate design options/feasibility

Virtual combustion system optimization

Experimental validation of optimized combustion system

Vehicle level analysis and cost assessment

Perform engine tests on optimized hardware

Develop vehicle level strategy/estimate vehicle level potential

Perform cost analysis

Design/build optimized engine hardware

Evaluate optimized configuration and

generate efficiency mapsDetermine vehicle level control strategy and fuel

economy potential

21

SUMMARY

Collaborative research project between FCA US LLC, Ford Motor Company and Argonne National Laboratory designed to evaluate an Efficiency-Optimized Dual Fuel Engine with In-Cylinder Gasoline/CNG Blending

Successfully demonstrated the efficiency and performance potential of the proposed concept and developed tools and a pathway towards assessing an optimized configuration including vehicle level simulations

Project is on schedule and has a clearly defined path to on-time completion


Project goal Target Status Target metPower density improvement 10% 13%

10.0 (NG PFI) to 11.3 bar (NG DI) IMEPYes

Efficiency improvement 10% 18%33.2 (E10 PFI) to 39.1% ITE (NG DI)

Yes

Retrofitability Yes Engine/system design complete YesPetroleum reduction 50% Not started (task 5) TBDPayback period 36 months Not started (task 5) TBD

22

TECHNICAL BACK-UP SLIDES

LEFT BLANK INTENTIONALLY

Technical Back-Up Slides

23

X-RAY MEASUREMENT DETAILSTechnical Back-Up Slides

Focused beam in raster-scan mode

Beam size 5 x 6 µm FWHM Divergence 3 mrad H x 2 mrad V Beam size constant across spray Time resolution: 3.68 µs Each point an average of 32-256

injection events Beer-Lambert law to convert x-ray

transmission to mass/area in beam

24

FUEL AND NG DI INJECTOR SPECIFICATIONSTechnical Back-Up Slides

Natural Gas (CNG)CH4, C2H6, CO2, N2 mol% 94, 3, 2, 1Methane number - 90.7Lower heat value MJ/kg 46.93Stoichiometric A/F Ratio - 16.2

Gasoline (E10)C, H, O wt% 82.08, 14.13, 3.79AKI (RON+MON)/2 - 87.2Lower heat value MJ/kg 42.017Stoichiometric A/F Ratio - 14.1

NG DI Injector Concept Outward Opening Multi-holeStatus Hardware tested Simulation onlyPressure range 6 – 16 barAsymmetry option No YesNozzle design changes No YesDiameter, tip 7.5 mmDiameter, maximum 21 mm

25

BASELINE MAPS WITH NEAT FUELS(NG PFI VS DI)

Similar efficiencies for bothfueling strategies

NG DI delivers significantlyhigher WOT IMEPcompared to NG PFI

NG DI achieved an IMEP of11.3bar at 1500rpm and WOT

Project target of 10% higher powerdensity for NG DI compared to NGPFI was exceeded

NG DI (side)NG PFI

Efficiency difference

13%


26

PREDICTIVE ENGINE SIMULATION VALIDATED AGAINST EXPERIMENTAL DATA Predicted effect of DI injection timing on mixture homogeneity and efficiency Correlated DI location effect on turbulence (TKE) with measured Flame

Development Angle (FDA) and Combustion Duration Provided insight for the optimization of in-cylinder mixing and turbulence

1

2

3

4

5

6

7

8

33.0

33.5

34.0

34.5

35.0

35.5

36.0

36.5

360 330 300 270 240 210 180 150 120

CO

V IM

EP [%

]

Indi

cate

d Th

erm

al E

ffici

ency

[%]

SOI [°CA BTDC]

SideCentral

1500 rpm5.6 bar IMEP

φ (CFD) and ITE

Largest difference between center and side is at SOI 120


27

COMPARATIVE EFFICIENCY ANALYSISTechnical Back-Up Slides

36.5%35.1%

36.2% 35.6%

3.0%

2.5%

2.5% 2.8%

5.0%

5.4%

5.9% 6.1%

1.3%

2.2%

1.4% 1.1%

0.6% 1.0%0.4% 0.7%

34

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47

NG DISOI -120°aTDCSOI -300°aTDC

IMEP 5.6 barSpeed 1500 rpm

SOI -540°aTDC

Effi

cien

cy/L

osse

s [%

]

IC RC HL GE IND

SOI -240°aTDC

E10 PFI

Theoretical efficiency similar for all conditions (CR, Gamma, Residuals)

Incomplete Combustion (IC) losses account for unburned fuel species

Real Combustion (RC) losses include combustion duration and phasing

Faster flame speeds of gasoline result in benefits compared to early NG DI (SOI -300°aTDC), later DI results in stratification affecting both, IC and RC

Heat Loss (HL) increase with later NG DI operation due to induced turbulence resulting from the injection event

Gas Exchange (GE) losses higher for E10 PFI compared to NG DI due to increased throttling requirements stemming from changes in mixture calorific value, charge cooling (E10 PFI vs. NG DI at SOI -120°aTDC) and air displacement with open valve natural gas injection

28

Documents

Efficiency-Optimized Dual Fuel Engine with in-cylinder … · we start with yes. efficiency-optimized dual fuel engine with in-cylinder gasoline/cng blending thomas wallner riccardo