PM, NOx and CO2; A Three Dimensional Trade‐Off, as opposed to … · Diesel Engine Operating Strategies PM, NOx and CO2; A Three Dimensional Trade‐Off, as opposed to a single‐pollutant

Diesel Engine Operating Strategies

PM, NOx and CO2; A Three Dimensional Trade‐Off, as opposed to

a single‐pollutant minimization

www.vir2sense.com

Dr. C. Barro LAV / Vir2senseDr. P. Kyrtatos LAV / Vir2senseProf. Dr. Boulouchos LAVDr. P. Elbert IDSCProf. C. Onder IDSC

OutlineIntroduction

• Passenger car Diesel engines in the past 20 years

Operation Optimization

• Trade offs of state‐of‐the‐art engines

• Available tools for most beneficial operation

o Systematic Optimization

• Model based approach

Future solutions

Diesel Engine Operating Strategies / 20th NPC 2

History

Common RailPower

Particulate FilterAcceptance

Multiple InjectionsNoise

Source: CAR Uni Duisburg Essen

Share of Diesel and Gasoline Powered Cars in Germany

3Diesel Engine Operating Strategies / 20th NPC

HistoryComplexity / degrees of freedom increased

Exhaust

1996:Injection timingEGR Rate(Waste Gate)

2016:Injection timing main injectionInjection timing pilot injectionInjection timing post injectionInjection share pilot /main / postFuel pressureBoost pressureEGR rateEGR temperatureShare LP / HP EGRSwirl levelEngine dp

1996:(DOC)(O2 Sensor)

2016:DPFDOCSCR/LNTO2 Sensor x2NOx Sensor x2T Sensor x2dp Sensor(Soot Sensor)


NOx

PM

Euro 6

NOx

SFCCO2

Euro 6

NOx

SFCCO2

Euro 6

NOx

PM

Euro 6

Optimization for 3 Degrees of FreedomGoals:

• All available strategies for PM‐Nox‐SFC‐Trade‐off

• Systematic procedure

Start‐of‐injection (SOI)Exhaust gas recirculation (EGR)

Swirl (SWV)compressor

throttleintercooler

exhaust gas recirculation

turbine

injection

swirl valve


2016:Injection timing main injectionInjection timing pilot injectionInjection timing post injectionInjection share pilot /main / postFuel pressureBoost pressureEGR rateEGR temperatureShare LP / HP EGRSwirl levelEngine dp

Recorded Measurements# operating conditions = 31

In every operating point• (4 pts)• (4 pts)• (4 pts)= 4*4*4 = 64 pts

Total = 1984 measurements

800 1000 1200 1400 1600 1800 2000 2200 2400 2600 28000

50

100

150

200

250

300

350

Dre

hmom

ent i

n N

m

Drehzahl in rpm

WLTPNEDCArbeitspunkte


FVV Project 1140: Emission Optimized Diesel Engine, final report, part IDSC, 2015

Steady‐state optimization

Optimization criterion:1 1

Optimum inputs for engine control unit (EGR, SWV, SOI) are a function of operating point and strategy:

, , , argmin.

, , , ,

Interpolation on4D‐map

(EGR, SWV, SOI)


Weighting PM vs Fuel Weighting NOx vs Fuel/PM


Emission – Efficiency Trade –off


Trade off surface at 1250 rpm andlow load

Trade off line at 2000 rpm and(high) load

1

0

0 200 400 600 800 1000 12000

10

20

30

40

Soo

t em

issi

ons

in m

g/km

0 200 400 600 800 1000 12007.2

7.4

7.6

7.8

8

8.2

Nitrous oxides emissions in mg/km

Fuel

con

sum

ptio

n in

l/10

0km

PM=10.9

0.80.7

0.60.3

Eur

o 6

0 200 400 600 800 1000 12000

10

20

30

40

Soo

t em

issi

ons

in m

g/km

0 200 400 600 800 1000 12007.2

7.4

7.6

7.8

8

8.2


Fuel

con

sum

ptio

n in

l/10

0km

PM=10.9

0.80.7

0.60.3

Eur

o 6

0 200 400 600 800 1000 12000

10

20

30

40

Soo

t em

issi

ons

in m

g/km

0 200 400 600 800 1000 12007.2

7.4

7.6

7.8

8

8.2


Fuel

con

sum

ptio

n in

l/10

0km

Eur

o 6

Trade‐off in NEDC‐Cycle

Simulation Benchmark• Optimized

1 +3.0%

2 +1.3%

3 +3.4%

4 +4.9%

5 +4.8%

6 +2.7%

0 200 400 600 800 1000 12000

10

20

30

40

Soo

t em

issi

ons

in m

g/km

0 200 400 600 800 1000 12007.2

7.4

7.6

7.8

8

8.2


Fuel

con

sum

ptio

n in

l/10

0km

Eur

o 6

0 200 400 600 800 1000 12000

10

20

30

40

Soo

t em

issi

ons

in m

g/km

0 200 400 600 800 1000 12007.2

7.4

7.6

7.8

8

8.2


Fuel

con

sum

ptio

n in

l/10

0km

Eur

o 6



Virtual Sensor Concept

Heat release rate modelSuperimposing of 3 Vibe‐functions

Calculation of pressure evolution

evaluation of characteristics e.g. pressure and temp. at a certain °CA°CA of peak HRR

ECU‐Data

Air path ActuatorsSwirl valveEGR rateSOI (Squish)Air massEngine speedIntake pressure and temperature

Fuel pathInjection profileQuantity of main and pilot injectionFuel pressure

Virtual Sensors

Mean pressureIntegration of pdV IMEP

NOx modelrepresentative formation rate

NOx

Soot model3‐Phases: Formation, equilibrium and oxidation phase

Soot


Validation of the Virtual SensorsA B C

1200 1800 2400 rpm

~ 10 bar

~ 5 bar

~ 3 bar

321

BMEP

Crank angle [°CA a. GE TDC]240 280 320 360 400 440 480

Cyl

inde

r pre

ssur

e [b

ar]

0

20

40

60

80

100

Cylinder Pressure, Measured & Modelled based on HRR

Meas A1Model A1Meas A3Model A3Meas C3Model C3

AÖ

IVCEVO

1250 1300 1350 14000

100

200

soot

[mg/

m3 ]

virtual sensorsmeasurements

1250 1300 1350 14000

200400600800

NO

x [ppm

]

0 500 1000 1500 20000

1

2 x 106

cum

ulat

ive

soot

[-]

0 500 1000 1500 20000

5 x 107

timecum

ulat

ive

NO

x [-]


FVV Project 1140: Emission Optimized Diesel Engine, final report, part LAV, 2015

Calculated on‐line by ECU

Virtual Sensor based Optimization Goal:• Replace the 1984

measurement points with model input

• Easier conversion to a different engine

• Include more degrees of freedom

Quality of the solution depending on modelled sensitivity of actuators on emissions

0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

0.05

0.1

0.15

0.2

0.25

Soo

t [g/

kWh]

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5290

300

310

320

330

NOx [g/kWh]

BS

FC [g

/kW

h]

Measurement based

Model based

12Diesel Engine Operating Strategies / 20th NPCFVV Project 1140: Emission Optimized Diesel Engine, final report, 2015

SWV Sensitivity

Conclusion & OutlookOptimum Calibration• Best available trade‐off between soot, NOx and fuel consumption • Systematic procedure for optimum ECU calibration • Virtual sensor based calibration

o Using virtual sensors for Soot + NOx and IMEP

Future Work• Include more degrees of freedom (i.e boost pressure)• Adapt virtual sensors for alternative fuels• Include requirements from aftertreatment (i.e. exh. temperature, DPF

pressure, regeneration strategy, etc…) • Include transient cycles


Acknowledgements

Co‐Authors, for their contributionsSwiss Federal Office of Energy, for the financial supportFVV, for the financial support

You, for your kind attention


Documents

PM, NOx and CO2; A Three Dimensional Trade‐Off, as opposed to … · Diesel Engine Operating Strategies PM, NOx and CO2; A Three Dimensional Trade‐Off, as opposed to a single‐pollutant