Advanced Petroleum Based Fuel Effects in HCCI (Agreement 13415) · 2008-04-23 · Biodiesels from a Variety of Sources in HCCI Combustion. Presented at the AOCS International Congress

Advanced Petroleum Based Fuel Effects in HCCI(Agreement 13415)

Bruce Bunting, Jim Szybist, Scott Sluder, Scott Eaton, Sam Lewis, and John Storey

Research supported by DOEFuel Technology Program,Kevin Stork and Dennis Smith are DOE management team

THIS PRESENTATION DOES NOTCONTAIN ANY PROPRIETARY

OR CONFIDENTIAL INFORMATION

Managed by UT-Battellefor the Department of Energy

Advanced Petroleum Based Fuel Effects in HCCI

• Goals and objectives

• 2007 reviewer feedback

• Barriers addressed

• Approach

• Accomplishments

• Technology transfer

• Summary

• Activities for next year

2 Managed by UT-Battellefor the Department of Energy

Goals and objectives

• Define tradeoffs and performance of fuels in advanced combustionregimes to support decisions related to future fuels and engineswith emphasis on: • Fuel economy • Fuel chemistry and properties • Engine control and emissions control • Both gasoline and diesel engines are being studied

• Advanced petroleum based fuels (APBF) are primarily derived frompetroleum crude, but may utilize non-traditional processing and may contain non-petroleum components

• This is a companion project to another covering non-petroleum based fuels (NPBF) which is reported separately


2007 reviewer comments

• Expand studies to include surrogate fuels … more chemical or specific molecular effects … more bulk vs. species specific effects …pre-screening using kinetic modeling – Added kinetic modeling and surrogates to research with refinery

based fuels – Added advanced statistics to allow performance analysis of

complex, real fuels • Get more students involved

– We are open to joint work, but have limited funding for university research. Please contact us with ideas or opportunities.

• Reviewer positive comments – “Work is vital if LTC is to succeed, well aligned with DOE goals, tie

between advanced combustion and fuel chemistry is essential,variety of fuels and engines being considered makes results universal, excellent database being created, good engagement andcollaboration with energy companies and OEMs, focus on datamining and statistics is a good approach, comparing full boilingrange fuels to surrogates is very valuable”


Barriers addressed

• The development of new engines and combustion regimes isbeing driven by need for greater fuel efficiency and reduced emissions – Research to date indicates that advanced combustion is

more sensitive to fuel variations

• Fuels research is needed to support decisions about future fuels, new fuel sources, and development of advanced engines

• New engines will need to provide robust performance across a wider range of fuels and conditions – Greater diversity of fuel sources – ‘World engines’

• Engines will need ability to compensate for fuel changes


INTAKE AIR HEATER

ATOMIZING INJECTOR

ENGINE

BELT DRIVE

CONSTANT SPEEDMOTORING DYNO

INTAKE AIR HEATER

ATOMIZING INJECTOR

ENGINE

BELT DRIVE


Mercedes 1.7L and Motoring Dyno

INTAKE AIR HEATER

ATOMIZING INJECTOR

ENGINE

BELT DRIVE


Approach • Use a variety of research engines

– Mercedes 1.7 and GM 1.9 for PCCI / HECC studies

– Single cylinder engines forHCCI: to emphasize fueleffects and minimize fuel sample requirements

• Study wide variety of both refineryfuels and surrogate blends

• Use statistical analysis to minedata in order to develop a broaderunderstanding of fuel behaviorand to extract information relative to complex, market fuels

• Apply kinetic modeling asappropriate


INTAKE AIR HEATER

ATOMIZING INJECTOR

ENGINE

BELT DRIVE

CONSTANT SPEED MOTORING DYNO

Mercedes 1.7L and Motoring Dyno

Accomplishments / progress / results

• Optimum engine efficiency is achieved by correctly matching a fuel toengine characteristics – Combustion phasing (MFB50) typically optimum at 5 to 10°ATDC – Must also avoid excessive rates of cylinder pressure rise and NOx

and high levels of CO and HC due to combustion quenching • Variable compression ratio is an effective control strategy for HCCI

engines and is capable of rapid control changes • Advanced statistical analysis (principal components analysis) is ideal

for analyzing fuel and engine performance data to deal with thenumber of correlated variables typically found in real fuels

• Octane and cetane numbers remain major variables for fuel definition for HCCI, but fuel chemistry also plays a significant role in combustioncharacteristics

• CRADA with Reaction Design for Model Fuels Consortium provides access to kinetic modeling tools and another dimension of application for our fuels research data


60

Fuel effects and diesel HCCI

• Engine managementwill need to compensate for fuelcetane number

• ISFC, ITE, and NOX all deteriorate with ‘heavy’ fuels

– Higher density – Higher T50 – Higher aromatics – Lower LHV

• Joint study withCummins and BP


CETANE SPECIFIC GRAVITY

% MONO AROMATIC

% POLY AROMATIC T50 LHV

CETANE 1.00

SPECIFIC GRAVITY -0.41 1.00

% MONO AROMATIC -0.67 0.00 1.00

% POLY AROMATIC -0.31 0.97 -0.17 1.00

T50 0.14 0.74 -0.48 0.78 1.00

LHV 0.59 -0.96 -0.25 -0.90 -0.56 1.00

INTAKE TEMPERATURE VS. CETANE FOR BEST ISFC

R2 = 0.9279

50

100

150

200

250

300

30 35 40 45 50 55

CETANE NUMBER

INTA

KE

TEM

PE

RAT

UR

E, d

eg C

HEATING VALUE EFFECT

R2 = 0.40

0.00

0.50

1.00

1.50

2.00

19,000 19,200 19,400 19,600 19,800 20,000

heating value, btu/lb

NO

x, g

/kg

fuel

DENSITY EFFECT

R2 = 0.54

195 200 205 210 215 220 225 230

0.81 0.83 0.85 0.87 0.89

density

ISFC

, g/k

Wh

HIGHER RON

2121Straight run naphthaStraight run naphtha Gasoline HCCI –20 RON = 64.720 RON = 64.7

1919 VCR is a good control for HCCI1818

1717 • Temperature and CR are 1616 interchangeable for control 1515

1414 • VCR provides faster 1350 100 150 200

1350 100 150 200 2121250250 response than temperature

Intake TemperatureIntake Temperature (C( )C) 20% cert gasoline20% cert gasoline 20 RO20 N = 70.9RON = 70.9

Com

pres

sion

Rat

ioC

ompr

essi

on R

atio

• Higher RON requires higher

Com

pres

sion

Rat

ioC

ompr

essi

on R

atio 1919 temperature and/or CR1818

1717 • Un-throttled operation1616 requires higher temperature1515

1414 and/or CR 1313 2121

50 100 150 200 25050 100 150 200 250Intake Temperature (C) Intake Temperature (C)2020

Com

pres

sion

Rat

ioC

ompr

essi

on R

atio 1919

Red = un-throttled1818(lambda 2.1 to 2.6)1717

20% ethanol20% ethanol Blue = constant16 RO16 N = 79.8RON = 79.8lambda (2.1)1515

1414

131350 100 150 200 25050 100 150 200 2509 Managed by UT-Battelle

for the Department of Energy Intake Temperature (C)Intake Temperature (C)

Effect of CR on efficiency is not ‘more is better’• Efficiency increases with compression ratio, until rate of

cylinder pressure rise increases heat loss from combustion chamber

• Cooling losses (from simple heat balance) increase with higherrate of cylinder pressure rise, which can occur from higher CR,more advanced timing, and/or higher intake temperature

100100 55

WWBrake WorkBrake Workbrakbrake WWFriction WorkFriction Workfrictionfriction 508080

Ener

gy D

istr

ibut

ion

(%)

Ener

gy D

istr

ibut

ion

(%)

45 6060

QSensibleQSensible exh,senexh,senEnergy inEnergy in ChemicalChemicalQQ

exh,chemexh,chemEnergy inEnergy in Q

(%)

cool 40

40 Exhaust40 ExhaustExhaustExhaust 35

20 Cooling20 Cooling 30 QQLossesLossescooco lol

00 25 355 TDC 365 370 375355 TDC 365 370 375 0 5 10 15 20

CA 5CA 05 0 PRR m ax

(bar/deg)


FACE fuels - Fuels for advanced combustion engines

• DOE funded, CRC administrated, multiple national labs

• Specify and supply standard sets of diesel and gasoline fuelsfor advanced combustion research

– Diesels designed, manufactured, in analysis – Gasolines designed, out for bid

• ORNL has diesel fuels in house – Running in HCCI on single cylinder research engine


– Running in HECC on Mercedes 1.7 engine

Ignitability

VolatilityChemistry

Cetane Number

Aro

mat

s

T90(°C

) 30 45

20

35

270

340

8

Aro

ma

ic

1, 2006 diesel fuel

3

5

2

4

6

7 Center (of cube)

Cetane Number

tics

T90(°C

)30 45

2035

270

340

1, 2006 diesel fuel

3

5

2

84

6

7 Center (of cube)

Stoichiometric HCCI, ignition improvers, and TWC

• Ignition improver (TBP, EHN) does improve gasoline HCCI ignition– High doses required – may not be

commercially feasible– EHN also increases NOx emissions

• High EGR HCCI engines can be run atstoichiometric condition– Opens the door for use of TWC for

high load NOx control and light load CO and HC control

– Very challenging application foraged catalysts• Low exhaust temperatures • High CO and HC

– Control issues with stoichiometric operation

– Loss of fuel economy withstoichiometric operation

• Research results will be presented atSandia MOU meeting next month


TWC action, 457-521 deg.C cat in

0

10

20

30

40

50

60

70

80

90

100

0.96 0.98 1.00 1.02 1.04 1.06 1.08 1.10

lambda

% re

duct

ions

% CO % HC %NOX

3 bar IMEP, ISFC vs. Lambda

215

220

225

230

235

240

245

0.95 1 1.05 1.1 1.15 1.2

lambda

IS FC

, gm

/kw

-hr

TWC CONVERSION VS. LAMBDA

ISFC VS. LAMBDA

Advanced statistics for understanding fuels related data

• We are using principal components analysis (PCA) – Past use at ORNL for analysis of fuels and emissions data – Independent variables are resolved into orthogonal

eigenvectors – Allows inclusion of all variables, it is not necessary to

choose between multiple correlated variables – Maintains correlations between independent variables as

they exist in the original data – Well suited for the analysis of fuels and engines, which

often have multiple correlated variables • We build model into a simulator format so that experiments can

be ‘rerun’ on a computer to focus on specific effects or operating conditions – Still can’t extrapolate beyond limits of the experimental data

• Bonus project – re-analysis of AVFL13 HCCI gasoline results


Cooperative research program withReaction Design for Model Fuels Consortium

• Gain access to comprehensive set of kinetic modeling tools

• Provides another dimension of usefulness for our fuels and engine data – OEM and energy company members – Some results will be jointly published

• ORNL contribution - studies of diesel and gasoline range surrogate fuels

– Mining of past data – Parametric modeling studies – Gasoline, diesel, and bio-fuel surrogate blend experiments

• Gasoline experiments complete


Technology transfer

• Funds-in project with Cummins and BP – HECC and HCCI fuel effects and engine optimization

• Funds-in project with major energy company

• CRADA with Reaction Design for Model Fuels Consortium

• Presentations, technical papers

• APBF/NPBF, Invited speaker at 4 fuels and combustion related workshops and symposia in 2007 (SAE HCCI Symposium, AOCS World Biodiesel Congress, Univ. of Wisconsin Future Fuels Symposium, and Oil Sands Research RoadmapWorkshop)

• Reanalysis of AVFL13 data using PCA


2007 APBF/NPBF publications and presentations• Bunting, Strategies for Optimization of Engines, Fuels, and Aftertreatment. ERC

Research Symposium, University of Wisconsin, June 2007. • Szybist, McFarlane, and Bunting, Comparison of Simulated and Experimental

Combustion of Biodiesel Blends in a Single Cylinder Diesel HCCI Engine, SAE technical paper 2007-01-4010.

• Szybist and Bunting., The Use of Fuel Chemistry and Property Variations to Evaluate the Robustness of Variable Compression as a Control Method for Gasoline HCCI, SAE technical paper 2007-01-0224.

• Szybist and Bunting, The Effects of Fuel Composition and CR on Thermal Efficiency in an HCCI Engine, SAE paper 2007-01-4076.

• Bunting, Eaton, Szybist, Crawford, Yu, and Wolf, The Performance of B20 Biodiesels from a Variety of Sources in HCCI Combustion. Presented at the AOCS International Congress on Biodiesel, November 2007.

• Bunting, Wildman, Szybist, Lewis, and Storey, Fuel Chemistry and CetaneEffects on Diesel Homogeneous Charge Compression Ignition Performance, Combustion, and Emissions. International Journal of Engine Research, vol 8, p 15-27, 2007.

• Szybist and Bunting, Compression Ratio, Lambda, and Fuel Composition Effects on Gasoline-Range HCCI. Combustion MOU Presentation, February 2007.

• Oil sands research roadmap workshop, deer talk, presentation to diesel crosscut


Summary

• Optimum engine efficiency is achieved by correct matching of a fuel toengine characteristics – combustion phasing (MFB50) in the range of 5 to 10°ATDC – balance excessive rates of cylinder pressure rise and NOx against

high levels of CO and HC due to combustion quenching

• Variable compression ratio is a effective combustion control strategyfor HCCI engines and is capable of rapid control changes

• Advanced statistics in the form of PCA allows analysis of correlatedfuel variables, which are often present in market fuels

• Octane and cetane numbers are major variables for fuel definition forHCCI, but fuel chemistry plays a larger role in than it does inconventional combustion

• The Reaction Design Model Fuels Consortium allows ORNL access tolatest kinetic modeling tools and provides another avenue ofapplication for ORNL fuels research data


Activities for next year

• Continue to study effects of fuel properties and chemistry onHCCI combustion for real and surrogate fuels

• Determine more definite rules for matching fuels and engines in order to achieve maximum fuel efficiency

• Develop understanding of how engines can be controlled tocompensate for varying fuel properties in order to maximum economy while meeting other requirements

• Continue to mine past data as we learn new things


Reviewer summary

• Support goal of petroleum displacement – Define performance characteristics of new fuels and new combustion

regimes, with emphasis on fuel economy. Help support decision making about future directions.

• Approach – Diverse engine platforms, wide range of fuels, surrogates and refinery

fuels, statistical analysis, kinetic modeling • Technical accomplishments and progress

– Match of engine and fuels to achieve optimum efficiency – Wide range of fuels studied – Multiple platforms

• Tech transfer / market transformation – Funds-in projects, CRADA, publications

• Next year’s plans – Continue data mining, modeling, experimentation, efficiency analysis

• Noteworthy aspects / barriers – Statistics applied to market fuels, surrogates and modeling for deeper

understanding


Documents

Advanced Petroleum Based Fuel Effects in HCCI (Agreement 13415) · 2008-04-23 · Biodiesels from a Variety of Sources in HCCI Combustion. Presented at the AOCS International Congress