Reduction of Diesel Emission by

using High Pressure Loop EGR

and Low Pressure Loop EGR

Yuzo aoyagi

Masayuki Kobayashi

New A.C.E. Institute Co., Ltd.

2530 Karima, Tsukuba-shi, Ibaraki Pref.

305-0822, Japan

Title

Contents

1. Target and Engine Spec.

2. New Technologies

3. Fuel and Lubricant

4. Combination of HP and LP EGR

5. JE05 Transient Test Result

6. Summary

2

Contents

Target of Super Clean Diesel (SCD)

No. Item Content

1 NOx

PM (g/kWh)

0.2

0.01 w/ After-treatment

1.0

0.10 w/o After-treatment

2 CO2 (g/kWh) 670~680

3 Power Same or Better

4 Noise Same or Better

3

Explain of the “SCD”

SCD Engine configurations

Configurations

Engine Type DI, In-Line 6

Bore × Stroke Φ122 mm × 150 mm

Displacement 10,520 cm3

Compression Ratio 15.3

Swirl Ratio 1.0 ~ 9.0

Injection Nozzle Φ0.139 mm × 8-155°

Target

Max

Output

Engine Speed 2000 rpm

Output 298{405} kW {PS}

BMEP 1.7 MPa

Max

Torque

Engine Speed 1400 rpm

Output 1842{188} Nm {kgm}

BMEP 2.2 MPa

4

2011-01-0369

Contents

1. Target and Engine Spec.

2. New Technologies

3. Fuel and Lubricant

4. Combination of HP and LP EGR

5. JE05 Transient Test Result

6. Summary

5

Contents

Combustion Concept

SCD Concept

No. Concept

1 Lean Combustion (Burning by much O2 amount

and low combustion temperature)

2 High Boosting (Burning in high density air)

3 Fuel Injection at high Density Air (Reduction of peak fuel/air ratio)

4 High Pressure Fuel Injection (Smoke reduction by fine atomization)

5 High BMEP (Reduction of friction and heat loss)

6 Wide speed range and High Rate of EGR

(Drastic NOx reduction)

6

7

New Tech

6. Pair of big EGR cooler

1. SCD T/C

9. After treatment ・De-NOx cat. ・DOC ・DPF ・NOx sensor ・λ Sensor

2. Pmax=20MPa

・Cyl. head

・Cyl. head GKT

・Cyl. Block

・FCD piston

2. Shallow dish C/C

8. Variable swirl

3. Injector

4.5. HP-EGR & LP-EGR

3. Pinj=200MPa common rail Supply pump

10. SCD ECU for JE05

7. VVA & High boost 4 valve

New Technologies Adopted in SCD

Photos of the VGT VGT

Current SCD VGT

8

Compressor Compressor

Turbine Turbine

SCD Turbocharger

2011-01-0369

VGT compressor map

Current SCD VGT

9

Comparison of Compressor Map

SCD Turbocharger

SCD Engine at Exhaust Side

Supplementary information 8

10

New ENG Block diagram

11

VVA

VGT

Swirl Valve

Reed Valve

After-treatmentLP-EGR Cooler

LP-EGR Valve

O2Sen.Boost Sen.

Inte

rC

oo

ler

Fuel Injector

LN

T+

CO

CD

PF

NO

xS

en

so

rB

ack

Pre

ssu

reV

alv

e

HP-EGR ValveHP-EGR Cooler

TI Engine Layout

SCD After-treatment system

After-treatment system

LNT DOC

Pressure and Temperature SensorsExhaust Gas

DPF

Type Volume Quantity

De-NOx Catalyst 8.5L（Φ10.5”×6”） 2

Diesel Oxidation Catalyst 8.5L（Φ10.5”×6”） 1

Diesel Particulate Filter 17.0L（Φ10.5”×12”） 1

12

Contents

1. Target and Engine Spec.

2. New Technologies

3. Fuel and Lubricant

4. Combination of HP and LP EGR

5. JE05 Transient Test Result

6. Summary

13

Contents

Fuel and Lubricant Specifications 1

Category Property Category Property

Density 15°C g/cm3 0.8212 Elements mass % C 86.1

Kinematic H 13.8 mm2/s Viscosity 30℃

3.244 H 13.8

O -

Flash Point °C 66.0 N <0.1

Cetane Index （JIS K2280）

59.0 Components vol. %

Saturates 81.3

Olefins 0.0

Cetane Number 58.2 Aromatics 18.7

Distillation IBP 170.5 Mono- 17.5

5% 190.5 Di- 1.0

10% 201.5 Tri- 0.2

50% 273.0 Calorific Value kJ/kg 45990

90% 333.0 Lower Calorific kJ/kg Value

43100 EP 360.5

Sulfur mass ppm 7

Lubricity HFRR（WS1.4） μm 272

14 Fuel Properties

Fuel and Lubricant Specifications 2

Category Properties

Density 15°C g/cm3 0.859

Flash Point (COC) °C 226

Kinematic

Viscosity

40°C 68.82

100°C 10.55

Pour Point °C -35.0

Sulfuric Ash Content mass % 1.00

Sulfur mass % 0.26

15

Lubricant oil Properties

Contents

1. Target and Engine Spec.

2. New Technologies

3. Fuel and Lubricant

4. Combination of HP and LP EGR

5. JE05 Transient Test Result

6. Summary

16

Contents

Explanation of

High Pressure EGR Index (HPI)

Explanation of HPI

17

HPI % =

HP-EGR Rate

Total EGR Rate (HP-EGR+LP-EGR)

×100

HPI =100% ; HP-EGR only HPI = 70% ; HP-EGR 70% + LP-EGR 30% HPI = 0% ; LP-EGR only

For Example

Sm

oke

FS

N

BS

NO

x g

/kW

h

BS

FC

g/k

Wh

BS

FC

g/k

Wh

Sm

oke

FS

N

Total EGR rate % BSNOx g/kWh

HPI=100%

Around 1% increase

HPI=60%

Around 50% reduction

Ne BMEP SOC Pinj. VGT/N

= 1200 rpm = 0.83 MPa = TDC = 160 MPa = 78% Close

Effect of EGR on Steady State Test 18

HPI=100% HPI= 60% HPI= 30% HPI= 0%

with BPCV with BPCV with BPCV

Fixed VGT nozzle position

Steady state test with fixed VGT 1

Sm

oke

FS

N

BS

NO

x g

/kW

h

BS

FC

g/k

Wh

BS

FC

g/k

Wh

Sm

oke

FS

N

Total EGR rate % BSNOx g/kWh

T/C

Sp

ee

d

×1

0rp

m

Ga

kg

/min

In

take

O2%

P

3 k

Pa

(Ga

ge

)

Gt

kg

/min

P

b k

Pa

(Ga

ge

) E

xce

ss A

ir

Ra

tio

VG

T

Clo

sin

g %

P

ME

P M

Pa

FSN=0.5 HPI=100%

FSN=0.5 HPI=60%

Steady state test with fixed VGT 2 Total EGR rate %

T/C

Speed

×1

0rp

m

Ga k

g/m

in

Inta

ke O

2%

P

3 k

Pa(G

age

)

Gt

kg

/min

P

b k

Pa

(Ga

ge

) E

xce

ss A

ir

Ra

tio

V

GT

Clo

sin

g %

P

ME

P M

Pa

Ne BMEP SOC Pinj. VGT/N

= 1200 rpm = 0.83 MPa = TDC = 160 MPa = 78% Close

HPI=100% HPI= 60% HPI= 30% HPI= 0%

with BPCV with BPCV with BPCV

T/C

Sp

ee

d

×1

0rp

m

Ga

kg

/min

In

take

O2%

P

3 k

Pa

(Ga

ge

)

Gt

kg

/min

P

b k

Pa

(Ga

ge

) E

xcess A

ir

Ra

tio

V

GT

Clo

sin

g %

P

ME

P M

Pa

Combination of HP & LP EGR

Fixed VGT

nozzle position

19

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

0 5 10 15 20 25

Pre

ss

ure

Ra

tio

Volumetric flow m3/min

Operating points on the compressor map 2

EGR rate 15%

19%

21%

25%

23%

(HPI=10~42%)

20

Ne Load

= 800,1000,1200 1400,2000 rpm = 100%

Combination of HP & LP EGR

Contents

1. Target and Engine Spec.

2. New Technologies

3. Fuel and Lubricant

4. Combination of HP and LP EGR

5. JE05 Transient Test Result

6. Summary

21

Contents

Result of the emissions at transient test cycle with after-treatment

JE05 Transient Test Result ×

10rp

m

NO

x p

pm

To

rqu

e N

m

Ne

rp

m

Op

acity %

T/C

Sp

ee

d

×1

0 r

pm

Time sec

×10rp

m

NO

x p

pm

To

rqu

e N

m

Ne

rp

m

Op

acity %

T/C

Sp

ee

d

×1

0 r

pm

Time sec

Previous Setting (HP-EGR)

Improved Setting (HP-EGR and LP-EGR)

* without after-treatment

22

0.00

0.05

0.10

0.15

0 0.5 1 1.5

PM

g/k

Wh

NOx g/kWh

withDPF

with DPF&LNT

Target using after-treatment

Result of the emissions at transient test cycle with after-treatment

0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5

PM

g/k

Wh

NOx g/kWh

HP-EGR

HP-EGR(Base)

+LP-EGR+Inj. Timing

+ValveTiming+VGT

(a)

(b)

ENG out target

0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5

PM

g/k

Wh

NOx g/kWh

HP-EGR

HP-EGR(Base)

+LP-EGR+Inj. Timing

+ValveTiming+VGT

(a)

(b)

ENG out target

0.00

0.05

0.10

0.15

0 0.5 1 1.5

PM

g/k

Wh

NOx g/kWh

withDPF

with DPF&LNT

Target using after-treatment

0.00

0.05

0.10

0.15

0 0.5 1 1.5

PM

g/k

Wh

NOx g/kWh

withDPF

with DPF&LNT

Target using after-treatment

23

JE05 Transient Test Result

Summary (1/2)

The effects of VGT, HP-EGR, LP-EGR, and each device on steady state and transient operations were verified using a super clean diesel engine. The following results are obtained. 1) Important technologies such as high-pressure

fuel injection of 200 MPa, a high boost pressure ratio up to 5 with the new VGT, and an EGR system of HP-EGR and LP-EGR, which enables a large amount of EGR, were selected as effective measures to reduce exhaust emissions by the JE05 transient test.

Conclusion 1

24

2) Combining HP-EGR and LP-EGR, as in this study’s EGR system, is proposed. It increases the EGR rate at a medium load up to 35%. Finally, a low NOx value such as NOx=1.0 g/kWh without an aftertreatment is obtained. 3) The EGR system of HP-EGR and LP-EGR used for this study has performance that increases EGR while maintaining BSFC and the boost pressure and decreases NOx and PM simultaneously, not only in the steady- state condition but also in the transient condition.

Conclusion 2

25 Summary (2/2)

Acknowledgements

The authors acknowledge that this study has been

supported by New A.C.E. and the Next Generation

Low-Emission Vehicle Project by the Ministry of

Land, Infrastructure and Transport, Japan.

We also express our deepest gratitude to people

and companies who kindly cooperated with

component development, fabrication and experiment

in this project.

END

Acknowledgements

26