Performance Evaluation of the Delphi Non-Thermal Plasma ... · PDF fileDynamics & Propulsion Innovation Center Performance Evaluation of the Delphi Non-Thermal Plasma System Under

Dynamics & Propulsion Innovation Center

Performance Evaluation of the Delphi Non-Thermal Plasma System Under Transient and Steady State Conditions

8th Diesel Engine Emission Reduction ConferenceSan Diego, CaliforniaAugust 25-29, 2002

Joseph V. Bonadies, Joachim Kupe, Galen B. Fisher, Craig L. DiMaggio, David A. Goulette, Thomas W. Silvis, Mark Hemingway, William J. LaBarge

Delphi Corporation

Darrell R. Herling, Monty R. Smith, John G. Frye, Mark A. GerberPacific Northwest National Laboratory


Acknowledgements

California Energy Commission Diesel Emissions Carl Moyer Demonstration Program

Jerry Wiens


Test Vehicle ConfigurationNTP Assisted Catalyst Evaluation

u 2000 European production vehicle with 2.2 L common rail engine – Delphi development EMS– Production FIE– Euro 3 emission certification

u System Configuration – DPF + Reactor + Catalysts

u 20 Cell Parallel Plate NTP Reactor– 15.4cc active area

u 2.5 liter SiC DPF (non-catalyzed)

u DeNOx Catalyst (Stabilized)– Ag Al2O3 (1.67L) (Catalyst 1)– Ag Ba-Y-Z (3.35L) (Catalysts 2 & 3)– Pt oxidation (0.98L) (Catalyst 4)

u Power Supply – 220VAC – Power control based on Speed/Load– 15KHz Pulse Density Modulation (PDM)– Power supply efficiency 80% from wall to gas


Pulse Density Modulation (PDM)Power Delivery Control

u Pulse density modulation power control– Fixed Amplitude (6kV peak)– Automatic resonant frequency control (Fc » 15 – 20 kHz)– Variable repetition rate based on speed/load

u US Patent 6,423,190 pulse density modulation for uniform barrier discharge in a non-thermal plasma reactor


Vehicle Exhaust Configuration

56cm6689

99119127142158

Catalyst NTP DPF


0

10

20

30

40

50

60

70

80

90

100

0 200 400 600 800 1000 1200

Time(sec)

NO

->N

O2

Co

nve

rsio

n (%

)

0

50

100

150

200

250

300

350

400

450

500

Tem

per

atu

re (d

eg C

)

Reactor Efficiency

Reactor Inlet Temp

Vehicle Speed

NTP Reactor EfficiencyMVEG Cycle

• NO to NO2 conversion > 90% over ECE


Net NTP ReactorNO Conversion Efficiency

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 200 400 600 800 1000 1200

Time (s)

Cu

mu

lati

ve N

O (

g)

0

50

100

150

200

250

300

350

400

450

500

Wh

slp

d(k

ph

)

NO Reactor In CumulativeNO Reactor Out CumulativeWhlspd

67%

80%

• 80% cumulative NO to NO2 conversion up to mid EUDC• 67% cumulative NO to NO2 overall


0

100

200

300

400

500

600

700

800 810 820 830 840 850 860 870 880 890 900

Time(sec)

NO

(pp

m),

NO

x(p

pm

), V

ehic

le S

pee

d(k

ph

)

NO

NOx

HC

Vehicle Speed

In-cylinder Post Injection TimingNTP Reactor Outlet

• Transient control provides HCs from post injection that arrive at plasma and catalyst ahead of NOx spike

Post Injected HC

Modal NOx


0

200

400

600

800

1000

1200

1400

0 200 400 600 800 1000 1200

Time

Po

wer

(wat

ts),

Veh

icle

Sp

eed

(kp

h)

Avg Wall Power

Avg Reactor Power

Vehicle Speed

NTP Power Consumption

• Transient control of NTP power demonstrated• 350 Watt average over MVEG


Fuel Economy Penalty

u Power Consumption– Fuel Economy Penalty: 5 %

u Post Injected HC– Fuel Economy Penalty: 3 %

u Total Fuel Economy Penalty = 8 %


NTP Assisted Catalysis NOx Performance


0

100

200

300

400

500

600

700

0 100 200 300 400 500 600 700 800

Time(sec)

NO

x(p

pm

)

0

50

100

150

200

250

300

350

400

450

500

Tem

per

atu

re (d

eg C

), V

ehic

le S

pee

d (k

ph

)

Engine Out NOx

Tailpipe NOx

Catalyst Inlet Temp

Catalyst Outlet Temp

Vehicle Speed

Adsorption Desorption NOx Reduction

NOx Concentration ECE

Prep: 3 hot MVEG + cold soak

• NOx adsorption, desorption, and then reduction through ECE cycle


0

100

200

300

400

500

600

700

800

900

1000

800 850 900 950 1000 1050 1100 1150 1200

Time(sec)

NO

x(p

pm

)

0

50

100

150

200

250

300

350

400

450

500

Tem

per

atu

re (d

eg C

), V

ehic

le S

pee

d (k

ph

)

Engine Out NOx

Tailpipe NOx

Catalyst Inlet Temp

Catalyst Outlet Temp

Vehicle Speed

NOx Concentration EUDC

• Low NOx efficiencies during high speed portion of EUDC• Large NOx desorption during final deceleration


Catalyst Bed TemperaturesC395 MVEG Run #470 Stabilized ABBP Catalyst - Run #1

w/ NTP & w/ Diesel Post InjectionCatalyst Temperatures

0

100

200

300

400

500

600

0 200 400 600 800 1000 1200

Time(sec)

Tem

per

atu

re(d

egC

), V

ehic

le S

pee

d(k

ph

)

Catalyst INCatalyst OutVehicle SpeedCat 1Cat 2Cat 3Cat 4

• Catalyst bed temperatures stay below 300° C until last 100 s of MVEG• Emphasizes the performance of the low temperature zeolite catalyst


0

10

20

30

40

50

60

70

80

90

100

150 200 225 250 300 350 400 450

Catalyst Temperature (C)

NO

x R

edu

ctio

n E

ffic

ien

cy (%

)

SGB Concentration200 ppm NO500 ppm C3H610% O25% H2O7% CO2Balance N2

Test ConditionWith NTP at a constant 150CSV = 38k/h for each brick or

19k/h total

Synthetic Gas Bench (SGB) Catalyst Performance

NOx Reduction Efficiency of Ag-alumina + Ag-Ba-Y-zeolite Catalyst(1 washcoated brick of the alumina followed by 1 brick of the zeolite)

• Synthetic gas bench (SGB) testing used to identify candidate catalysts


Engine Dyno Steady State PerformanceC3H6 vs Post Injection - 150°C

Stabilized Catalyst1200 RPM, 27Nm, 97ppm NO, 150ppm NOx

-20

0

20

40

60

80

100

Ag Al2O3 Ag Ba Y Zeolite

NO

x C

on

vers

ion

(%)

w/ 500 ppm C3H6 w/NTP stabilized

w/ Post Injection w/NTP stabilized

Performance with C3H6agrees with SGB testing

Space VelocityAg Al2O3 40k/hrAg BaYZ 20k/hr

• With HC from post-injection, <20% NOx conversion • 50% NOx conversion similar on dyno and SGB with 500 ppm propene• Near 15% with only propene & no NTP


Engine Dyno Steady State PerformanceC3H6 vs Post Injection - 350°C

Dyno TestingStabilized Catalyst

2000 RPM, 68Nm, 200ppm NO, 200 ppm NOx

-20

0

20

40

60

80

100

Ag Al2O3 Ag Ba Y Zeolite

NO

x C

on

vers

ion

(%)

Performance with C3H6 < half of SGB testing at 38 K h-1

w/ 500 ppm C3H6 w/NTP stabilized

w/ Post Injection w/NTP stabilized

Space VelocityAg Al2O3 100k/hrAg BaYZ 50k/hr

• With HC from post-injection, negative NOx conversion • NOx conversion @ 100 K h-1 SV expected to be less than SGB data @ 38 K h-1


NTPR Acetaldehyde ProductionEngine Dyno Steady State

0102030405060708090

150C 350C

NTP inlet Temp (C)

CH

3CH

O P

rod

uct

ion

(p

pm

)

PostInject

Propene

Acetaldehyde is the most efficient reductant used by these NOx catalysts

• With post injection, insufficient appropriate HC species exist in the exhaust to yield sufficient acetaldehyde

[97 ppm EO NO] [200 ppm EO NO]


u 15 % NOx total system efficiency over MVEG cycle – 30 % ECE, 3% EUDC– NOx adsorption and desorption affected catalyst efficiencies– Ag Al2O3 catalyst not fully exercised due to low exhaust temperature

u Reactor exhibits good NO->NO2 conversionuGreater than 85% HC and 62% CO efficiency on cold

MVEG with low temperature oxidation catalyst as rear bricku Diesel post injection calibration improved reactor efficiency

during transientsuModest power levels are seen at low speed/load steady

state operating points

Vehicle Test Summary


DPF Regeneration


DPF Dynamometer Testing


0

2

4

6

8

10

12

0 10 20 30 40 50 60

Time ( Hours )

DP

F P

ress

ure

Dro

p (

kPa

)

0

10

20

30

40

50

60

Soo

t Loa

ding

( g

ram

s )

NTP-DPF DPF only NTP-DPF Soot DPF only Soot

26.6 gms

38.1 gms

11.0 kPa

6.7 kPa

7.3

9.5

30.1

20.2

12.8 14.6 17.719.1

21.7 24.2

EO NOx: 347 ppm EO NO: 301 ppm EO HC: 22 ppm

Speed / Load: 2000 RPM / 85 Nt m Engine Flow: 43 gm/sec

EO PM: 1.7 gm/hr No EGR DPF (Type / Size): SiC / 4.1 liter

Reactor Power: 600 Watts Reactor NO2 Efficiency: 16.2%

DPF Regeneration305 C DPF Inlet Temperature

• Continuous regeneration occurs at 305 C with ~100 ppm NO2 in exhaust • DPF backpressure and soot loading reduced with NTP compared to DPF only


DPF RegenerationSummary

u NTP reactor reduces exhaust PM mass 20% to 30%

u Continuous regeneration of a non-catalyzed DPF was demonstrated with the NTP reactor

u Three-way interaction exists between:– Soot loading– DPF inlet temperature– NO2 concentration


Conclusions

u NTP Reactor & Power Supply performance is acceptable– Potential to reduce power consumption with short pulse power supply

u NTP assisted catalysis has low NOx performance over transient MVEG emission cycle

– Catalysts tested are too selective for the hydrocarbon species present in the exhaust

– NOx adsorption and desorption is a major challenge– Catalyst durability and performance requires much more development

resources

u NTP has the potential to enable continuous regeneration of a non-catalyzed DPF, given the proper levels of temperature, soot loading, and NO2

Documents

Performance Evaluation of the Delphi Non-Thermal Plasma ... · PDF fileDynamics & Propulsion Innovation Center Performance Evaluation of the Delphi Non-Thermal Plasma System Under