advanced ca for euro 4

8/10/2019 Advanced CA for EURO 4

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Advanced Combustion

Analysis for reducingemissions and fuel

consumption

Race to EURO 4

Pune, 18. July 2006

Franz Murr

AVL List GmbHGraz / Austria


2/70

Race to EURO 4, Advanced Combustion Analysis FM / MIV

content

current situation

link between combustion and emission

examples for combustion with high emissions

how to assess emissions from combustion analysis?

accuracy requirements for the measurement chain

optical methods for emission reduction

conclusion


3/70


current situation

Pollution

Legislation

EURO2

EURO3

EURO4

beyond EURO4 ?


4/70Race to EURO 4, Advanced Combustion Analysis FM / MIV

current situation

Oil Price

Car Buyer

less fuel

consumption



current situation

link between combustion and emissionexamples for combustion with high emissions

how to assess emissions from combustion analysis?accuracy requirements for the measurement chain


conclusion




misfiringmisfiring

knockknock

steep temp / pressure risesteep temp / pressure rise

too early combustiontoo early combustion

too late combustiontoo late combustion

partial combustionpartial combustion

(wall film, condensation/cold(wall film, condensation/coldcomponents, overcomponents, over fuelingfueling, fat, fat

mixture, improper spray / geometry,mixture, improper spray / geometry,

)

HCHC

NOxNOx

NOxNOx

NOxNOx

HC, PM, sootHC, PM, soot

HC, PM, sootHC, PM, soot

)



basics of emissions reduction

NOxNOx

PM, sootPM, soot

HC

temp reductiontemp reduction -- EGREGR

premixed flamepremixed flame

nono unburntunburnt fuel, stablefuel, stable

combustion

HC

combustion



options for emission and fuel reduction

improved fuel qualityimproved fuel quality

lubricationlubrication -- less frictionless friction

exex--gas after treatmentgas after treatment direct fuel injectiondirect fuel injection

injection timinginjection timing

lean / very lean mixturelean / very lean mixture

multimulti--pulse fuel injectionpulse fuel injection

improved transientimproved transient

calibrationcalibration(cold start, acceleration, de(cold start, acceleration, de--))

load exchange optimisationload exchange optimisation

combustion chamber designcombustion chamber design



Influence of injection parameters

Power/Torque

Appl.EffortHC PM NoiseNOX

High Injection Pressure

Late Start of Injection

Pilot Injection

Injection Rate Control

Nozzle Hole Quality

Post Injection

Negative EffectPositive Effect



external emission measurement

analyser for gaseousanalyser for gaseous

componentscomponents

measurement ofmeasurement of

particulate matterparticulate matter

calculation of thecalculation of the

smoke numbersmoke number


11/70


internal emission measurement

fast relieve valvesfast relieve valves

cylinder pressurecylinder pressuremeasurementmeasurement

optical methodsoptical methods


12/70


fast relieve valves

advantage:advantage:

exact gas analysisexact gas analysispossiblepossible

disadvantage:disadvantage:

emission constituentsemission constituents

change rapidly over CA

soot production

change rapidly over CA


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cylinder pressure measurement


precise analysis of eachprecise analysis of each

cylinder in highestcylinder in highest

resolutionresolution

disadvantage:disadvantage:no direct emissionno direct emission

measurementmeasurement -- goodgood

understanding ofunderstanding ofcombustion processcombustion process

needed to read data

injection timing

needed to read data


14/70


optical methods


optimised methods foroptimised methods fordifferent problems;different problems;

direct access to differentdirect access to different

causes of emissionscauses of emissions


less introduced methodsless introduced methods


15/70


current situation



how to assess emissions from combustion analysis?accuracy requirements for the measurement chain


conclusion


16/70


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optical measurements flame okay

pcyl

flame

intensity

Radius is CA axis

Exhaust

Inlet

cylinder pressure and

flame intensity traces in

one diagram

polar diagram of 40 flame

intensity traces perfect angular

isotropy ideal

combustion


19/70


optical measurements diffuse flame

Radius is CA axis

Exhaust

Inlet

pcyl

flame

intensity

cylinder pressure and

flame intensity traces in

one diagram

polar diagram of 40 flame

intensity traces disturbed angular

isotropy flame anomaly,

diffuse flame


20/70


conditions at engine start

Mixture conditions at cold start.Schematic by Toyota, SAE

950074

Premixed combustion:

A/F = 1, all fuel evaporated

Ignition:

some fuel vapor

present near spark plug

diffuse combustion:

fuel film, very bright flame,

but low rate of heat release


21/70


reasons for bad combustion

Mixture conditions at cold start.

Schematic by Toyota, SAE

950074

-180 -90 0 90 180 27

Liquid film combustion:very bright flame,

but low rate of heat release

Premixed combustion:

pressure rise

as volume charge burns

Ignition: little fuel vapor near

spark plug causes small flame

Ignition phase disturbed by

overfuelliing, fuel droplets

hitting the flame kernel


22/70


impact of injection pressure

5 deg CA

300 bar

800 bar

medium injection pressure

some turbulence better soot burn off

low injection pressure

little turbulence

slow soot burn off

fast soot burn off 1000 bar

high injection pressure

increased turbulence

complete soot burn off

1 deg CA

slow soot burn off

AVL research engine with VisioScope


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current situation



how to assess emissions from

combustion analysis?



conclusion

f i i d f l t


25/70


causes for emissions and fuel waste

Gasoline engine: inadequate air/fuel ratio

insufficient mixture preparation

glow ignition

misfiring knock

late combustion

Diesel engine:

inadequate air/fuel ratio

improper spray geometry

high pressure rise (early combustion) insufficient mixture preparation

late combustion

AVL research engine with VisioScope

b ti ti i d i ib ti ti i d i i


26/70


combustion timing and emissionscombustion timing and emissions

NOX

HC

%

-- 44 -- 33 -- 22 -- 11 00 11 22 33 44 55 66deg CA

260260

220220

180180

140140

100100

6060

Em

ission

advanced retardedlowest SFC

SOI =SOI =

start of injectionstart of injection


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Basic Engine Data


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Basic Engine Data

ignition / injection mapignition / injection map

emission mapemission map

fuel consumption mapfuel consumption map

noise mapnoise map

exhaust temperature mapexhaust temperature map

......

influence of combustion on emissions


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influence of combustion on emissions

--100100 --8080 --6060 --4040 --2020 00 2020 4040 6060 8080 100100

soft combustionsoft combustion

-- lowlow NOxNOx

-- low noiselow noise

-- increased sootincreased soot

-- high HChigh HC

stiff combustionstiff combustion

-- highhigh NOxNOx

-- high noisehigh noise

RateofHe

atRelease


30/70

gasoline DI strategies


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gasoline DI strategies

SplitSplit--InjectionInjection PostPost--InjectionInjectionPrePre --InjectionInjection

Catalyst Heating(Startup, Idle)

Torque Increase(Full Load)

Efficiency Increase

Emmission

Reduction

Operating Mode

Change

DeNOX Cat.

Sulfur Removal

Combustion StabilityImprovement

tools for combustion evaluation


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tools for combustion evaluation


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current situation



accuracy requirements for the measurement

chain


conclusion

reason for high measurement accuracy


34/70


reason for high measurement accuracy

Consumption and emissions as function of DOI

1515 2020 2525 3030 3535 4040 deg CA

290290

285285

280280

275275

270270

265265

260260

Fuelconsum

ption

5

10

20

15

g/kWh

S

Duration of injection1515 2020 2525 3030 3535 4040 deg CA

3030

2525

2020

1515

1010

55

00

SOOT

g/h

20

15 10 5

S

Duration of injection

S = Start of Injection

emission as function of injection timing


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emission as function of injection timing

S = Start of Injection

1515 2020 2525 3030 3535 4040 deg CA

66

55

44

33

22

11

00

NOX

g/kWh

20

15 10

S


5

1515 2020 2525 3030 3535 4040 deg CA

1,21,2

1,01,0

0,80,8

0,60,6

0,40,4

0,20,2

00

HC

g/kWh

5 10

20

15

S


The Precision Measurement Chain


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The Precision Measurement Chain

efficient data

postprocessing

the measurement chain

consists of several

elements, each one

contributing to theoverall error !

high-speed

data acquisition

intelligentsignal conditioning

precise pressure

transducers


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Precision

Pressure Measurement

sensors - typical errors


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yp

}cylinderpres

sure

cylinderpres

sure

bar

bar

pp--pprefref

bar

bar

6060

4040

2020

00

--180180 00 180180 360360 540540

--22

44

66

00

Crank angleCrank angle degdeg

Testedsensor

IMEP error = 95.5 %heat rate error > 100 %

Error oftest sensor p-pref

Reference

sensor

Pressure differencep-pref = 3 - 8% error

linearity error

thermal sensitivity shift

cyclic (thermal) drift

IMEP stability

mounting error

acoustic noise from

adapters

acceleration noise

calibration error

GaPO4 the ideal crystal for combustion


39/70


4 y

200 300 400 500temperature [C]

2.4

2.0

0 100 600

sensitivity[pC/N]

5.0

4.8

4.9

4.7

GaPO4 optimized

GaPO4 x-cut

quartz x-cut2.3

2.2

2.1

quartz optimized

5.1

temperature stable (up to 400 C) crystal


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wide range of 4.7 to 7 mm sensors


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accuracy comparable to

10 mm water cooled

sensors less mounting space

required

integration into sparkplug or glow plug

no water cooling

required

convenient mounting with adapters


42/70


Precision measurement in

glow plug adapters

easy mounting no change in combustion

chamber volume

no pipe oscillations due to sort

passage bore suitable for all kind of calibration

and testing work


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intelligent signal conditioning


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-360 -300 -240 -180 -120 -60 0 60 120 180

range setting

bandwidth

drift compensation

ground loop noise

sensor setting

calibration error

cable noise and

leakage

3066A02

[bar]

-4

0

4

8

12

16

20

24

28

32

36

Amplifiers - typical errors

CDM[deg]

Amplifiers - filtering error


45/70


Crank angleCrank angle degdeg

Filtering of ground loop noise

resulting errors with low pass 12 kHz:

pmax = 1%, dp/dmax = 15%, IMEP = 0%

MFB 50% = 0,6%, SOC = 0.5 %resulting errors with low pass 6 kHz:

pmax = 2%, dp/dmax = 27%, IMEP = 0%

MFB 50% = 0%, SOC = 1,5 %

AVL microIFEM - the perfect solution


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no low pass filtering required due

to noise suppression design

no drift error because of perfect

drift compensation

all settings remote controlled

automatic best range setting by

integrated sensor identification

wide temperature range -30 .. +

60C

high speed data acquisition


47/70


offset correction methods

filtering

calculation method

calculation range

synchronisation error

errors in data acquisition

cylinder pressure correction


48/70


Zero Line Correction error = 0.35 bar

resulting errors:

pmax = 2%, IMEP = 0%

MFB 50% = 9%, EOC = 33.6%

cylinder pressure correction


49/70


TDC Correction error = 1 deg CA

resulting errors:

pmax = 0,12%, IMEP = 1.4%,MFB 50% = 7%, EOC = 4.2%

IndiAdvanced Combustion Analyser


50/70


family of proven systems high degree of flexibility

guided set-up with many

control functions

on-line control functions

for signal quality check

standardised algorithm for

signal calibration, zero linecorrection and TDC

determination

intelligent data processing software


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Features:

intuitive graphical interfaces for- parameterisation

automatic adjustments

(e.g. consideration of intakepressure)

integrated plausibility checks

predefined functions

- calculation

- automation

IndiComIndiCom

Log-pV Diagram for error check


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VOLUME [log V]VOLUME [log V]

-- 0,80,8

-- 0,40,4

0,00,0

0,40,4

0,80,8

1,21,2

1,61,6

2,02,0

-- 1,01,0 -- 0,80,8 -- 0,60,6 -- 0,40,4 -- 0,20,2 0,00,0

PCYL1[logbar]

PCYL1[logbar]

Error Causes: Zero Level

too high:

too low:

TDC

too early: too low

too late: too high

Compression Ratio

too high: too low

too low: too high

1

..PolytropicPolytropic CoefficientCoefficient

~ 1,32~ 1,32 GasolineGasoline

~ 1,37 Diesel~ 1,37 Diesel

error in zero level correction


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-- 0,80,8

-- 0,40,4

0,00,0

0,40,4

0,80,8

1,21,2

1,61,6

2,02,0

-- 1,01,0 -- 0,80,8 -- 0,60,6 -- 0,40,4 -- 0,20,2 0,00,0

PCYL1[log

bar]

PCYL1[log

bar]

bar

CATDC

PCyl too low

Pcyl too high

VOLUME [log V]VOLUME [log V]

+/- 500 mbar Zero Level Error are clearly visible!

evaluation of multiple injection


54/70


N eed

le_li

ft[%

]

Cyl _

pre

ssu

re[

bar

]

NOx reduction

noise reduction

HC/smoke reduction

ROHR

MBF

SOI, EOI, DOI

SOC, EOC

flame temp

Pcyl

Needle Lift

SOI

EOI

DOI

comparison of achieved improvements


55/70


min

meanmax

var%

min

mean

maxvar%

min

mean

maxvar%

Crank Angle [deg]]

Cyl1 Cyl2 Cyl3 Cyl4

location of cycles with bad combustion


56/70


Misfiring

IME

P

[bar]

Unstable

Combustion

Cylinder


57/70


current situation





conclusion

more advanced tools - injection analysis


58/70


spray geometryspray geometry

VisioScopeVisioScope

mixture preparationmixture preparation

VisioFlameVisioFlame// VisioFEMVisioFEM

flame propagationflame propagation

VisioFlameVisioFlame

EGREGR GCAGCA


59/70

optical measurements

Vi i TVi i T


60/70



full information overfull information over

entire cylinder crossentire cylinder cross

section with highest CAsection with highest CA



only two dimensionalonly two dimensional

information; expensiveinformation; expensiveequipmentequipment

VisioTomoVisioTomo

15.56 KW

15.08 KW

14.48 KW up to 120 channelsup to 120 channels


Vi i l tiVi i l ti


61/70



good information overgood information over


section with highest CAsection with highest CA



lower spatial resolutionlower spatial resolution

VisiolutionVisiolution

14%

8%

up to 40 channelsup to 40 channels


Vi i S tVi i S t


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rough information overrough information over


section and goodsection and good

information on flameinformation on flame

around spark plug witharound spark plug with

highest CA resolutionhighest CA resolution


lowest spatial resolutionlowest spatial resolution

VisioSetVisioSet

-60CA

140

up to 8 channelsup to 8 channels


63/70

VisioFEM


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Urgent statement of a leading diesel car producer:

Our CR injection systems operated in stationary engine tests

we manage to optimise for low soot and NOx.

But we do not understand how to optimise CR in transient mode!

How much pilot, pre- main- post injection ?

How many crank angle degrees in between ?How do we adapt to changing load, boost pressure, residual gas ?

We need a real time, crank angle resolved transient data

acquisition for soot and NOx.

optical sensor in

glow plug adapter

fibre optics cable

optical amplifier

600nm 950nm

how to read the data?

we get traces of


65/70

... we get traces of

- injection- cylinder pressure

- flame intensity

flame intensity

amount of soot

two-colour flame

evaluation

temperature / NOx

= f (EOI)

trend verification with

Filter Smoke Number (FSN)0

0.02

0.04

0.06

0.08

0.1

0.120.14

0.16

0.18

-15 -10 -5 0

FSN

0.05

0.1

0.15

0.2

0.25

D_

VFEM

-rel.units

IMEP:

5 bar

EOI5

figure of merit

USP and benefits


66/70


0

5

10

15

20

0 100 200 300cycle nr.

IMEP

bar

IMEP

opacity

transient operation

visio-soot

transient operation possibletransient operation possible

correlation between integralcorrelation between integral

value acquired at test bedvalue acquired at test bed

andand VisioFEMVisioFEM resultsresults

easyeasy handlinghandling

cyclecycle resolvedresolved resultsresults

added value


67/70


fits perfectly into

AVL Indicating measuring chain

full integration in IndiCom

(parameterisation, calculation

and

data display)

application hints for the user


68/70


current situation






conclusion


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conclusion optical measurement


70/70


optical methods can be

applied with for detailed

combustion analysis

effects not visible with

pressure analysis can be

studied in detail giving adeeper understanding of

the actual combustion

tailored solutions for

typical problems available

advanced ca for euro 4

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