DKittelson(UMinnesota) Ethanol HCCI · 2020. 3. 13. · • Homogeneous charge compression ignition (HCCI) engines utilize a ... – Hydrogen injection - ethanol used was the primary

Center for Diesel Research

Nanoparticle emissions from an ethanol fueled HCCI engine

David B. Kittelson and Luke FranklinCenter for Diesel Research

Department of Mechanical EngineeringUniversity of Minnesota

Cambridge Particle Meeting21 May 2010

University Engineering DepartmentTrumpington Street, Cambridge, UK



Outline

• Introduction

• Experimental apparatus

• Dilution sensitivity

• Results– Engine performance

– Variable intake temperature

– Role of solid particles

– Preliminary hydrogen results

• Conclusions


Renewable fuel research

• Ethanol / H2 HCCI

• Ethanol / H2 Diesel

• Synthesis gas HCCI / PCCI / fumigation

• DME Diesel

• FAME, ULSD, and hydro-treated vegetable oil in Caterpillar ACERT Diesel

• Cold flow filter plugging with FAME

• Butanol Diesel / SI


HCCI

• Homogeneous charge compression ignition (HCCI) engines utilize acombination of high compression ratio and premixed highly dilute charge to achieve low temperature premixed combustion that avoids both soot formation and significant NOx formation but CO and hydrocarbon emissions are high

• It is difficult to utilize this type of combustion at high engine loads and it is difficult to control the timing of the combustion process.

• We explored three means of controlling the combustion timing andmeasured the resulting gaseous and particle emissions– Intake air heating– Exhaust gas recirculation– Hydrogen injection - ethanol used was the primary fuel because it can easily be

reformed to make hydrogen

• Number and mass emissions of nanoparticles were of the same order as those from contemporary Diesel engines without aftertreatment but the particles were nearly all volatile


Typical engine exhaust particle size distribution by mass, number and surface area

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

1 10 100 1,000 10,000

Diameter (nm)

Nor

mal

ized

Con

cent

ratio

n (

1/C t

otal

)dC

/dlo

gDp

Number Surface Mass

Fine ParticlesDp < 2.5 µm

Ultrafine ParticlesDp < 100 nm

NanoparticlesDp < 50 nm

Nuclei Mode - Usually forms from volatile precursors as exhaust dilutes and cools

Accumulation Mode - Usually consists of carbonaceous agglomerates and adsorbed material

Coarse Mode - Usually consists of reentrained accumulation mode particles, crankcase fumes

PM10Dp < 10 µm

In some cases this mode may consist of very small particles below the range of conventional instruments, Dp < 10 nm

2pDNS π= 6/

3pDNm ρπ=

Kittelson, D.B. 1998. “Engines and Nanoparticles: A Review,” J. Aerosol Sci., Vol. 29, No. 5/6, pp. 575-588, 1998


Carbonaceous agglomerates comprise most of the mass from Diesel engines but are largely eliminated by HCCI

metallic ash

semi volatile droplets

Without Exhaust Aftertreatment


Outline

• Introduction







• Conclusions


Experiment apparatus

PM Emissions Instrumentation

•CPC, SMPS EEPS

Gas Phase Emissions Instrumentation

•NOX, CO, HC, CO2, O2

Dilution System

Engine

Dynamometer

The test engine is a modified 2005 model year Isuzu medium duty engine. The base engine is a 5.3 liter, 4 cylinder engine, turbocharged, aftercooled with common rail fuel injection.


Engine modifications for HCCI

• Turocharger and aftercooler removed

• Common rail Diesel fuel injection not used

• Primary fuel ethanol preheated to improve atomization

• Independent control of EGR, air temperature, hydrogen, ethanol

• Closed loop controlled thermal system capable of maintaining temperatures of 150 °C

• MoTeC engine management system used for fuel injector control

EGR Manifold

Main EGR Line

EtOH Injectors EtOH Fuel Rail

H2 Fuel Rail

H2 Injectors

Intake Manifold

Thermal Management System

EGR Control

Temperature Feedback


Particles were measured with a nano DMA and a 3025 ultrafine CPC configured to scan from 2 to 64 nm


A catalytic stripper was used to differentiate volatile and solid particles

• Recent stripper design– Stripper consists of a 2 substrate catalyst* followed by a cooling coil

– The first substrate removes sulfur compounds

– The second substrate is an oxidizing catalyst

– Diffusion and thermophoretic losses present but well defined*Catalysts were provided by Johnson-Matthey

Kittelson, D. B.; Watts, W. F.; Savstrom, J. C.; Johnson, J. P. Influence of catalytic stripper on response of PAS and DC. J. Aerosol Sci. 2005, 36, 1089–1107.


Sampling and dilution system

Nano SMPS, other instruments

Primary dilution air temperature, 25 – 45 C

Primary dilution tunnel temperature 25 – 45 C

Secondary dilution air temperature, 25 C

Dilution ratios, primary = 18, secondary = 15Residence time ~ 1.5 sec


Outline

• Introduction







• Conclusions


The first thing we wanted to do was to establish dilution conditions – dilution sensitivity

0.0E+00

2.0E+08

4.0E+08

6.0E+08

8.0E+08

1.0E+09

1.2E+09

1.4E+09

1 10 100Dp (nm)

dN/d

logD

p (p

artic

les/

cm3 )

S1=25°C, T =25°C S1=35°C, T =25°C S1=45°C, T =25°CS1=25°C, T =35°C S1=35°C, T =35°C S1=45°C, T =35°C


The first thing we wanted to do was to establish dilution conditions – dilution sensitivity

1.0E+05

1.0E+06

1.0E+07

1.0E+08

1.0E+09

1.0E+10

1 10 100 1000Dp (nm)

dN/d

logD

p (p

artic

les/

cm3 )

S1=25°C, T =25°C S1=35°C, T =25°C S1=45°C, T =25°CS1=25°C, T =35°C S1=35°C, T =35°C S1=45°C, T =35°C


Comparison with earlier Diesel dilution sensitivity experiments

1.00E+05

1.00E+06

1.00E+07

1.00E+08

1.00E+09

1.00E+10

1 10 100 1000

Dp (nm)

DN

/DLo

g D

p (P

art./

cm³)

Tdil (32 °C) Tdil (48 °C) Tdil (65 °C)

Residence Time ~ 400 ms, Primary DR ~ 12Humidity Ratio ~ 0.0016

1600 rpm, 50% load

1.0E+05

1.0E+06

1.0E+07

1.0E+08

1.0E+09

1.0E+10

1 10 100 1000

Dp (nm)dN

/dlo

gDp

(par

ticle

s/cm

3 )S1=25°C, T =25°C S1=35°C, T =25°C S1=45°C, T =25°CS1=25°C, T =35°C S1=35°C, T =35°C S1=45°C, T =35°C

Abdul-Khalek, I., D.B. Kittelson, and F. Brear. 1999. “The Influence of Dilution Conditions on Diesel Exhaust Particle Size Distribution Measurements,” SAE Paper No. 1999-01-1142, 1999.

The sensitivity to dilution conditions is somewhat less than we have observed with Diesel nanoparticles. We decided to go with intermediate tunnel and dilution air temperatures, 35 and 35 C, respectively


Outline

• Introduction







• Conclusions


Variation of output with intake temperature for 3 fixed fueling rates, 1500 rpm

0

20

40

60

80

100

120

140

90 100 110 120 130 140 150 160

Intake Temperature (°C)

Bra

ke T

orqu

e (N

m)

λ = 5

λ = 3.75

λ = 3.0


Outline

• Introduction







• Conclusions


Ethanol HCCI with varying Intake Temperature, λλλλ~4.5, 1500 RPM, No EGR

0.0E+00

2.0E+08

4.0E+08

6.0E+08

8.0E+08

1.0E+09

1.2E+09

1.4E+09

1.6E+09

1.8E+09

2.0E+09

1 10 100

DP (nm)

dN/d

logD

P (

part

icle

s/cm

3 )

T=110

T=120

T=130

T=140

T=150

T=160



0

1000

2000

3000

4000

5000

6000

90 100 110 120 130 140 150 160


CO

and

HC

(pp

m)

0

2

4

6

8

10

12

14

16

18

20

NO

x (p

pm)

CO

HC

NOx



0.0E+00

2.0E+08

4.0E+08

6.0E+08

8.0E+08

1.0E+09

1.2E+09

1.4E+09

1.6E+09

1.8E+09

2.0E+09

1 10 100

DP (nm)

dN/d

logD

P (

part

icle

s/cm

3 )

T=90

T=100

T=110

T=120

T=130



0

1000

2000

3000

4000

5000

6000

90 100 110 120 130 140 150 160


CO

and

HC

(pp

m)

0

2

4

6

8

10

12

14

16

18

20

NO

x (p

pm)

CO

HC

NOx



0.0E+00

5.0E+08

1.0E+09

1.5E+09

2.0E+09

2.5E+09

3.0E+09

3.5E+09

4.0E+09

4.5E+09

1 10 100

DP (nm)

dN/d

logD

P (

part

icle

s/cm

3 )

T=90

T=100

T=108

T=110



0

1000

2000

3000

4000

5000

6000

90 100 110 120 130 140 150 160


CO

and

HC

(pp

m)

0

2

4

6

8

10

12

14

16

18

20

NO

x (p

pm)

CO

HC

NOx


Summary total number emissions

0.0E+00

2.0E+08

4.0E+08

6.0E+08

8.0E+08

1.0E+09

1.2E+09

TIn = 90 TIn = 100 TIn = 110 TIn = 120 TIn = 130 TIn = 140 TIn = 150 TIn = 160

Inlet Temperature °C

Tot

al N

umbe

r (p

artic

les/

cm3 )

Low Load Mid Load 1Mid Load 2


Summary total estimated mass emissions – these are at Diesel engine levels

0.0E+00

1.0E+03

2.0E+03

3.0E+03

4.0E+03

5.0E+03

6.0E+03

TIn = 90 TIn = 100 TIn = 110 TIn = 120 TIn = 130 TIn = 140 TIn = 150 TIn = 160

Inlet Temperature °C

Tot

al M

ass

(µµ µµg

/m3 )

Low Load Mid Load 1Mid Load 2


Outline

• Introduction







• Conclusions


What about solid particles – here are some results with and without the catalytic stripper at light load

0.0E+00

2.0E+08

4.0E+08

6.0E+08

8.0E+08

1.0E+09

1.2E+09

1 10 100

DP (nm)

dN/d

logD

P (

part

icle

/cm

3 )

Tin=120 Tin=120, CSTin=140 Tin=140, CSTin=160 Tin=160, CS Hot Mo Hot Mo, CS

Solid particles

Hot Mo refers to hot motoring with no fuel –atomized lube oil


Solid particles from previous slide 10x scale

0.0E+00

2.0E+07

4.0E+07

6.0E+07

8.0E+07

1.0E+08

1.2E+08

1 10 100

DP (nm)

dN/d

logD

P (

part

icle

/cm

3 )

Tin=120, CS

Tin=140, CS

Tin=160, CS

Hot Mo, CS

Hot Mo refers to hot motoring with no fuel –atomized lube oil. Why are there apparently more lube oil ash particles present during motoring?


Comparison with solid particles from a modern Diesel. HCCI nucleation mode particles much smaller but in higher concentration.

1.0E+05

1.0E+06

1.0E+07

1.0E+08

1.0E+09

1.0E+10

1 10 100 1000Dp (nm)

dN/d

logD

p (p

artic

le/c

m3)

Mode 2Mode 2 CSMode 5Mode 5 CS

1.0E+05

1.0E+06

1.0E+07

1.0E+08

1.0E+09

1.0E+10

1 10 100 1000DP (nm)

dN/d

logD

P (

part

icle

/cm

3 )

Tin=120Tin=120, CSTin=140Tin=140, CSTin=160 Tin=160, CS Hot MoHot Mo, CS


Outline

• Introduction







• Conclusions


Ethanol HCCI with varying fraction H 2 energy input, λλλλ~4.5, 1500 rpm, T intake = 130° C

0.0E+00

1.0E+08

2.0E+08

3.0E+08

4.0E+08

5.0E+08

6.0E+08

1 10 100DP (nm)

dN/d

logD

P (

part

icle

s/cm

3 )

H2 = 0%

H2 = 5%

H2 = 10%

H2 = 15%

H2 = 20%

H2 = 25%


Hydrogen HCCI with varying intake temperature, λλλλ~5, 1500 rpm, 50 N-m

0.00E+00

1.00E+08

2.00E+08

3.00E+08

4.00E+08

5.00E+08

6.00E+08

1 10 100DP (nm)

dN/d

logD

P (

part

icle

s/cm

3 )

H2, Tin = 95

H2, Tin = 100

H2, Tin = 105

Hot motoring


Outline

• Introduction







• Conclusions


Conclusions

• Significant mass and number emissions observed– Most of material between 10 and 50 nm– Nearly all volatile– Some solid particles between 3 and 10 nm– Particle emissions do not correlate with HC and CO emissions– Significant particle formation even with pure H2 fuel

• Lube oil must play an important role • Need to consider detailed in cylinder temperature history and impact on lube related

particles• Should explore other lube oil formulations and oil atomization mechanisms

• This is a work in progress – data collection and analysis continues– In-cylinder pressure measurements for heat release rates and IMEP– Variable EGR results– Additional hydrogen tests– This system could be test bed for lube oil generated particles with non sooting

systems, HCCI, DME, CNG, H2


Related work on HCCI particle emissions

-Increased EGR-decreased total PM

-Lack of dilution monitoring/control reported

DMS500

Gasoline

Mixed hot/cold intake streams, variable valve timing

Misztal et al (2009)

-NO2:NOX ≈12-17%

-VOF 75-90% for low load HCCI

-no nucleation mode PM present

-no dilution conditions reported

-HCCI showed more accum. mode PM and less nucl. mode PM than DISI

-Mid load HCCI yielded more and larger accum. mode PM than DISI operation

Findings

SMPS 3071A ,with 3022 CPC

DMS500SMPS, 2 stage dilutionInstrumentation

low sulfur(

Documents

DKittelson(UMinnesota) Ethanol HCCI · 2020. 3. 13. · • Homogeneous charge compression ignition (HCCI) engines utilize a ... – Hydrogen injection - ethanol used was the primary