stuttgart.de of heat-integrated exhaust

Institute for Chemical Process Engineering: www.icvt.uni-stuttgart.de

Institute for Chemical Process EngineeringProf. Dr.-Ing. U. Nieken

Böblingerstr. 72, 70199 Stuttgart, Germany

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Object-oriented modelling,

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Object-oriented modelling,

dynamic simulation and optimization

of heat-integrated exhaust purification systems

with ProMoT and DIANA

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MODEGAT

September 14 - 15, 2009, Karlsruhe, Germany

Jens Bernnat* , Matthias Rink, Ute Tuttlies, Ulrich Nieken

and Gerhart Eigenberger

Institute for Chemical Process Engineering: www.icvt.uni-stuttgart.deInstitute for Chemical Process Engineering: www.icvt.uni-stuttgart.de

Outline

1. Introduction

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2. Modelling and Simulation

with ProMoT and Diana

3. Simulation Results - Examples

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4. Summary and Outlook

MODEGAT Karlsruhe J. Bernnat et al. - Object-oriented modelling with ProMoT and DIANA15.09.2009


1. Automotive exhaust purification – state of the art

Diesel-

state of the art �� multi-component exhaust lines

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NOx-storage-reduction catalystT = 250 - 450°C(sulphur removal: T ≈ 750°C)

Diesel soot filter(regeneration atT ≈ 450 - 750°C)

Diesel-oxidation-T > 250°C

Exhaust temperature:

EGR-Valve

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Exhaust temperature:150 – 800°C


Commercial tools for simulation available


1. Exhaust purification – heat-integrated approach

Exhaust treatment separated from engine control

in one compact, autonomous exhaust treatment unit

outlet DOCNSC

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sidewise

engine

exhaust in

fuel burnerair

fuel

HEX DSF

engine • Full flexibility of equation based modelling

necessary (programming languages)

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necessary (programming languages)

• Convenience of “block oriented” tool preferred

��Lack of commercial tools


1. Heat integrated concepts – modeling approaches

Modular approach: Models reusable for different

constellations, complex system to solve library

exhaust out NSC

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cleaning

devices

HEX

burner

pipesFully integrated approach: new models and

extensive numerical studies necessary

exhaust out NSC

DOC

DSF

burner

exhaust in

heat exchanger

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pipes

sensors

observer

...

extensive numerical studies necessary

NSC

DOCburner

exhaust in

exhaust out

heat exchanger

DSF


1. Heat integrated concepts – modeling approaches

Requirements:

• easy set-up of model constellations

and simulation scenarios

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and simulation scenarios

• user-friendly “block-oriented” modelling

• flexibility of equation based modelling

• efficient solvers for complex coupled DAE problems

• full access to the source code

• efficient tools for parameter estimation,

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• efficient tools for parameter estimation,

optimization and numerical analysis

��our choice: ProMoT and DIANA


2. ProMoT and DIANA

(Max Planck Institute Dynamics of Complex Technical Systems, Magdeburg)

�Equation-based modelling

�DAE (index 1)

Modelling tool ProMoT

(Process Modelling Tool)

counter current heat-exchanger

DOCoutlet channel

inlet channel

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�Object-oriented concept

�Multiple inheritance

�Aggregation

�Model implementation

�Graphical modelling with GUI

engine burnerDOC

mixing module

burner

inlet channelengine

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ambient heat-exchanger


2. ProMoT and DIANA



�DAE (index 1)



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�Aggregation



�Text-based in language MDL

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�Equation analysis and optimization

�Symbolic differentiation in ProMoT


2. ProMoT and DIANA


Simulation tool DIANA

(Dynamic sImulation And Numerical Analysis Tool)


�DAE (index 1)

�Equation based models

�Object-oriented architecture



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�Aggregation



�Text-based in language MDL

�Modular and extensible

�Efficient numerical kernel

(solvers based on free code)

�Control via scripts

�Contains methods for

dynamic simulation and

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�Equation analysis and optimization

�Symbolic differentiation in ProMoT

numerical analysis

• free for academic groups under GNU General Public License

• full access to source, good support (MPI) and extensibility


3. Simulation Results – Heat-integrated system

Favorable mode of operation:

1) Fast start-up of the unit

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Two showcases how to use DIANA concerning

heat-integrated exhaust purification systems

2) Keep unit in ignited mode

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Dynamic simulation of heat-up

under drive-cycle conditions

to show behaviour of the system

Steady-state continuation

to show theoretical limits

of ignited states


3. Simulation Results – Example 1

Heat-up under drive cycle conditions (no cold-start application!)

Comparison of three system set-ups (Diesel):

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DOC (stand alone)

a) DOC with cold start burner

b) HEX with DOC and cold start burner �� heat-integrated system

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Set point: C350T INDOC °= C400T IN

DOC °=

Source: CaPoC8 Brussels; J. Bernnat et. al. - Heat integrated concepts for automotive exhaust purification


3. Dynamic Simulation –

Heat-up under drive cycle conditions

200

250

300

te

mp

era

ture

[°C

] speed

temperature engine outspeed[km/h]

300

400

500

tem

pera

ture

[°

C]

DOC out (with HEX and FB)

DOC out (with FB)

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Fast heat-up due to efficient use of the burner

0 200 400 6000

50

100

150

time [s] during 4 ECE15 cycles

te

mp

era

ture

[°C

]

60

40

20

00 200 400 600

0

100

200

300

time [s]

tem

pera

ture

[°

C]

engine out

DOC out

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Concerning DIANA:

Easy and fast set-up of simulation scenario

Efficient simulation of different coupled systems under drive-cycle conditions


3. Simulation Results – Example 2

Second Example: Steady-state continuation: stability of operation states

Simple model of integrated system for exhaust after treatment of CNG-engine*

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Simple model of integrated system for exhaust after treatment of CNG-engine*

counter-current

inlet

outlet

insulation

housing

catalyst section

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counter-current heat exchanger

catalyst section (hot side)

*www.ingas-eu.org

Counter-current heat exchanger with partially catalytically coated walls


3. Steady-state continuation – principlew

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Source: Mykhaylo Krasnyk, DIANA — An object-oriented tool for nonlinear analysis of

chemical processes, Max Planck Institute for Dynamics of Complex Technical Systems


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3. Steady-state continuation in two parameters

400Inflow temperature vs. fuel concentration

Variable: Temperature, Methane Concentration

Constant: 100 kg/h

0.2

0.4

0.6

0.8

1

Conversion vs. inflow temperature

Co

nvers

ion

[-]

upper stable branch

unstable branch

lower stable branch

2000 ppm

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200

300

400

Infl

ow

tem

pera

ture

[°° °° C

]

Cusp gives the

limits of ignition

and extinction

ignition line

extinction line

100 200 300 400 500 600

0

0.2

Inflow temperature [°°°° C]

Co

nvers

ion

[-]

2000 ppm

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0 2000 4000 6000 8000 100000

100

Methane concentration [ppm]

Infl

ow

tem

pera

ture

[

2000 ppm

extinction line


3. Steady-state continuation in two parameters

400Inflow temperature vs. fuel concentration

Variable: Temperature, Methane Concentration

Constant: 100 kg/h

0.2

0.4

0.6

0.8

1


Co

nvers

ion

[-]

upper stable branch

unstable branch

lower stable branch

2000 ppm

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200

300

400

Infl

ow

tem

pera

ture

[°° °° C

]

Cusp gives the

limits of ignition

and extinction

ignition line

extinction line

100 200 300 400 500 600

0

0.2


Co

nvers

ion

[-]

2000 ppm

1


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0 2000 4000 6000 8000 100000

100

Methane concentration [ppm]

Infl

ow

tem

pera

ture

[

extinction line

100 200 300 400 500 600

0

0.2

0.4

0.6

0.8

1


Co

nvers

ion

[-]

850 ppm

850 ppm


3. Steady-state continuation – CNG

4000

5000

Inle

t co

ncen

trati

on

Meth

an

e [

pp

m]

From the limit points we can extract more useful information! e.g.

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2000

3000

4000

Inle

t co

ncen

trati

on

Meth

an

e [

pp

m]

300 kg/h

200 kg/h

100 kg/h

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100 200 300 400 500 6000

1000

Inlet temperature [°°°° C]

Inle

t co

ncen

trati

on

Meth

an

e [

pp

m]

50 kg/h10 kg/h


4. Summary and outlook

• Object-oriented, equation-based modelling

• Flexible and fast set-up of model configurations

Summary:

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• Flexible and fast set-up of model configurations

• Easy set–up of simulation scenarios

• ProMoT1) and DIANA1)

• Advanced numerical packages for system design

• Simulation results

Outlook:

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1) Max Planck Institute for Dynamics of Complex Technical Systems

• Extension of model library

• Analysis and optimization of after treatment systems

• Development of control strategies


Acknowledgement:

Support of the

• Deutsche Forschungsgemeinschaft (DFG),

European Community (EU)

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Thank you for your kind attention!

• European Community (EU)

• MPI Magdeburg

is gratefully acknowledged.

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Questions?


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stuttgart.de of heat-integrated exhaust