GT Conference 2017: Simulation Tool for Predictive Control ... · © FH AACHEN UNIVERSITY OF...

© FH AACHEN UNIVERSITY OF APPLIED SCIENCES 09. October 2017 | 1

GT Conference 2017:Simulation Tool for Predictive Control Strategies for an ORC-System in Heavy Duty Vehicles

October 09-10, 2017

Dipl.-Ing. Jörg Kreyer M.Sc. FH Aachen

Prof. Dr.-Ing. Thomas Esch FH Aachen


• Scientific questions and solution methods

• Model intention and model features

• Data acquisition for heavy duty truck

• GT-Model presentation

• Longitudinal vehicle model incl. ORC-model

• 1-D engine model

• Predictive control strategies for ORC-system

• Summery and outlook

Content

GT Conference 2017


Scientific questions

• How can a non-stationary heat offering in the commercial vehicle be used to reduce fuel consumption?

• Which potentials offer route and environmental information among with predicted speed and load trajectories to increase the efficiency of a ORC-System?

Methods

• Desktop bound holistic simulation model for a heavy duty truck incl. an ORC System

• Prediction of massflows, temperatures and mixture quality (AFR) of exhaust gas

GT Conference 2017Scientific questions and solution methods


Radiator 1D-fuid components and control parameters

• Engine

• Injection and combustion

• EGR and TC

• Cooling circuit

• Pump and thermostat control

• Coupled Retarder

• ORC-System

• Working fluid: Ethanol

• Using of EGR and EAT Heat

• Electrical regeneration

• Actuators:

• ORC Fluid pump

• Split- and Bypassvalves

GT Conference 2017Model intention / Model features

Heat exchanger after EAT

T

G

M

Condenser

Massflow split valve

Bypass valve

Compen-sation tank

ORC pump

Generator/Expander

M

C

Retarder

Batterie

CAC

Recuperator

ORC cooling pump

CAC: Charge Air coolerEGR: Exhaust gas recirculationEAT: Exhaust aftertreatment

Heat exchanger after EGR

cooling pump


Vehicle configuration

• Actros 1845 LS / OM 471

• 330 kW @ 1800 RPM

• 2200 (2400 Top Torque) Nm @ 1100 RPM

• Displacement: 12,81 ltr. / 6 cylinder in-line

• Maximum Efficiency: ηeff = 46%

• EURO 6

• Gearbox: 12 gears

• 3 axes tarpaulin trailer

• Overall vehicle mass: 31700 kg

GT Conference 2017Data acquisition for heavy duty truck



TV

ሶ𝐕 𝐩 𝐓

ሶ𝐕 𝐩 𝐓𝐩 𝐓 𝐓

𝐩 𝐓

𝐓𝐓

λ 𝐩 𝐓 𝐓

𝐩 𝐓

Fleet-

board

𝐩 𝐓

λ 𝐩 𝐓

𝐩 𝐓

ሶ𝐦𝑳

RadiatorRetarder

CAC

EAT

EGR

FPI

CAC: Charge Air coolerEGR: Exhaust recirculation coolerFPI: Fuel post injectionEAT: Exhaust aftertreatment

distance radar

𝐩

Measuring scope:

• Temperature, pressure, AFR

• Analysation of video data

• Mass- and volume flow

• Bosch HFM 7-25.0

• Volumeflow radiator and retarder

• Venturi nozzle for AGR

J1939 Protocol / OBD II:

• diver load demand

• indicated engine load

• engine speed

• Friction torque

• Injection amount

• Injection begin

Volume flow radiator

Airflow before intake filter Venturi nozzle for EGR

Dashboard information

OBD II


Autobahn cycle: Aachen (AC)

Characterized by:

• High density of construction side

• High speed restrictions

• Less road gradient

Autobahn cycle: Aachen-Frankfurt-Aachen (AC-F-AC)

Characterized by:

• Traffic congestion

• Less speed restrictions

• High road gradient

Aldenhoven Testing Center (ATC) and Rural Road (RR)

• Stationary load points

• Cast down curves

• Breaking tests


0

160

320

480

640

800

0

20

40

60

80

100

0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 6 6,5 7 7,5

Gra

die

nt of

road [

m]

Vehic

le s

peed

[km

/h]

Driving time [h]

ATC

AC-F-AC

RR

0

500

1000

1500

2000

2500

400 800 1200 1600 2000

Teff

[Nm

]

Engine speed [RPM]

Full load curve

Top Torque

Load points ATC

Load Points CR

0160320480640800

020406080

100

0 0,5 1 1,5 2

Gra

die

nt of ro

ad

[m]

Vehic

le s

peed

[km

/h]

Driving time [h] Vehicle speed [km/h]Gradient of road [m]

AC


Status of the model development

• Vehicle dynamics, transmission and clutch controller

• Forward simulation done by driver model

• Fuel Consumption and heat release done by engine state model

• Operating characteristics of fluid systems: ORC and cooling circuit via Feed-forward controller

GT Conference 2017Longitudinal vehicle model incl. ORC-model

Model overview

ORC circuit model with single heat

input and recuperator

0

1

2

3

4

5

6

0 2000 4000 6000

ORC P

ow

er

outp

ut

[kW

]

Driving duration [s]

Transient Turbine Power Output

for Autobahncycle Aachen (AC)


GT-POWER Engine Modell OM 471

• Manifold desigen

• Valve timing

• Combustion

• EGR and Turbocharger performace control

GT Conference 2017Modelling: 1D GT-POWER engine model / OM 471

4321 5 6

CAC EGR

C TEGR

valve

EGR

throttle

1

1,5

2

2,5

3

3,5

4

4,5

5

0 0,2 0,4 0,6 0,8

Pre

ssure

Rato

[-]

Massflow [kg/s]

0,15

0,2

0,25

0,3

0,35

0,4

1,5 2,5 3,5 4,5M

assflow

[kg/s

]

Pressure Ratio Turbine [-]

ηmin=0,602ηmax=0,692

Turbocharger Maps

Source: Daimler AG,

2017 www.roadstars.mercedes-benz.com

0

500

1000

1500

2000

2500

Teff

[Nm

]

600 800 1000

Engine Speed [RPM]

400 1200 1400 1600 1800 2000

EGR Throttle position

nmin= 120000 1/minnmax= 30000 1/min

ηmin=0,61ηmax=0,78



Simulated Exh. massflow [g/s]

0

600 800 1000 1200 1400 1600 1800 2000400

500

1000

1500

2000

2500Measured exh. massflow [g/s]

0

600 800 1000 1200 1400 1600 1800 2000400

500

1000

1500

2000

2500

2,5

1,5

3,5

3

2

1

0,5

0

500

1000

1500

2000

2500

26

24

22

20

26

28

3432

30

2424

26

26

28

Simulated EGR Rate [%]

0

600 800 1000 1200 1400 1600 1800 2000400

500

1000

1500

2000

2500

600 800 1000 1200 1400 1600 1800 2000

Engine Speed [RPM]

400

Measured EGR Rate [%]

Teff

[Nm

]

0

10

20

30

40

50

60

1 2 3 4 5 6 7 8 9 10

EG

R R

ate

[%

]

Load Point [#]

EGR Rate (MEASUREMENT)

EGR Rate (SIMULATION)

0

50

100

150

200

250

300

350

1 2 3 4 5 6 7 8 9 10

m_Ex [

g/s

]

Load Point [#]

m_Ex (MEASUREMENT)

m_Ex (SIMULATION)

Engine Speed [RPM]

Teff

[Nm

]

Engine Speed [RPM]

Teff

[Nm

]

Engine Speed [RPM]

Teff

[Nm

]

Increasing Peff

Increasing Peff


0

100

200

300

400

500

600

700

1 2 3 4 5 6 7 8 9 10

T_AT [

°C]

Load Point [#]

T_AT (MEASUREMENT)

T_AT (SIMULATION)

0

100

200

300

400

500

600

700

1 2 3 4 5 6 7 8 9 10

T_BT [°

C]

Load Point [#]

T_BT (MEASUREMENT)

T_BT (SIMULATION)

Simulated Temp. after turbine [°C]

0

600 800 1000 1200 1400 1600 1800 2000400

500

1000

1500

2000

2500


Simulated Temp. before turbine [°C]

0

600 800 1000 1200 1400 1600 1800 2000400

500

1000

1500

2000

2500

Measured Temp. after turbine [°C]

0

600 800 1000 1200 1400 1600 1800 2000400

500

1000

1500

2000

2500

400

Measured Temp. bevor turbine [°C]

0

600 800 1000 1200 1400 1600 1800 2000400

500

1000

1500

2000

2500

550

500

450

400

350

300

350

300

250

200

Teff

[Nm

]

Increasing Peff

Increasing Peff

Engine Speed [RPM]

Teff

[Nm

]

Engine Speed [RPM]

Teff

[Nm

]

Engine Speed [RPM]

Teff

[Nm

]

Engine Speed [RPM]


Description of predictive control strategy:

• Multi-physical model vehicle (GT-SUITE)

• Restriction for the system behavior

• Energy prediction for the ORC system

• Basic controller and model predictive control (MPC) of ORC system

GT Conference 2017Predictive control strategies for ORC-system

Map based longitudinal vehicle

predictor model

GT model conventional

vehicle

GT model vehicle incl. ORC System

Load

𝛼, 𝑓𝑅, 𝑇𝑢,𝑝𝑢

Natural

Environment

Designed

Environment

𝑣𝑟𝑒𝑠

𝒙𝟏

𝒙𝟐n

Teff

TA

Prediciton of exhaust-enthalpy

ሶ𝒎A

n

Teff

Sim

ula

ted

Maps

Contr

olli

ng o

f

actu

ato

rs

Engine speed

Constraint optimization problem

T(t)

ሶ𝑚𝐴 tλ(t)

Restrictions:

• max. ORC fluid temperatures

• EGR temperature


Map based longitudinal vehicle predictor model:

• Designed Environment

• Legal speed restrictions

• Speed restrictions by traffic

• Natural Environment

• Road gradient:

• Roll resistance:

• Ambient conditions:

• Temperatur caclulation Map-based with first order delay element PT1:

Predictive control strategies for ORC-system

GT Conference 2017

DriverBalance of forces

Engine

Veh. Drivetrain

Load

n

𝑓𝑅𝑇𝑢𝑝𝑢

α

𝑖𝑔𝑒𝑠

Natural

Environment

Designed

Environment

𝑣𝑟𝑒𝑠

𝑣(𝑡)𝑎(𝑡) 1

𝑠

GT Power based lookup tables

𝑡𝑜𝑟𝑞𝑢𝑒

n

𝑑𝑈

𝑑𝑡=

𝑑

𝑑𝑡𝑐 ∙ 𝑚𝑤∙ Δ𝑇

ሶ𝑄𝑑𝑖𝑠𝑠

ሶ𝑚𝐸𝑥 ∙ 𝑐𝑝 ∙ 𝑇𝑖𝑛

ሶ𝑚𝐸𝐺𝑅 ሶ𝑚𝐸𝑥

𝑇𝐸𝑥𝑇𝐸𝐺𝑅

𝐿𝑜𝑎𝑑

PT1 PT1

ሶ𝐻𝑖𝑛 =

ሶ𝑚𝐸𝑥 ∙ 𝑐𝑝 ∙ 𝑇𝑜𝑢𝑡

ሶ𝐻𝑜𝑢𝑡 =

𝑓𝑅

𝑇𝑢, 𝑝𝑢

α

Engine

Torque


GT Conference 2017Predictive control strategies for ORC-system

100

200

300

400

500

600

Tem

pera

ture

befo

r tu

rbin

e[°

C]

-40

-20

0

20

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000

Absolu

te

devia

tion [

%]

Driving Time [s]

100

150

200

250

300

350

400

Tem

pera

tur

aft

er

EAT [

°C]

0

40

80

120

160

200

0

20

40

60

80

100

Gra

die

nt of

road [

m]

Vehic

le s

peed

[km

/h]

Driving profile: Autobahn Cycle AC Vehicle speed [km/h]Gradient of road [m]

-80

-40

0

40

Absolu

te

devia

tion

[%]

Measured

Simulated

Measured

Simulated


GT Conference 2017Summary and outlook

Summery

• A simulation tool for ORC performance analyzation in heavy duty trucks is created

• A strategy for energy prediction to ORC system was presented

• A data base of real driving data has been brought up

Next Steps

• Combining of 1-D engine model with driveline, coolant and ORC sub-systems

• Development of feed-backward controller for ORC system

© FH AACHEN UNIVERSITY OF APPLIED SCIENCES 09. October 2017

FH Aachen

Dipl.-Ing. (FH) Jörg Kreyer M.Sc.

European Centre for Sustainable Mobility

Aachener-und-Münchener Allee 1

52064 Aachen

[email protected]

T +49. 241. 6009 52827

F +49. 241. 6009 52489

FH Aachen

Prof. Dr.-Ing. Thomas Esch

European Centre for Sustainable Mobility

Hohenstaufenallee 6

52064 Aachen

[email protected]

T +49. 241. 6009 52369

F +49. 241. 6009 52680

mailto:[email protected]

mailto:[email protected]

GT Conference 2017: Simulation Tool for Predictive Control ... · © FH AACHEN UNIVERSITY OF...

Documents

Transcript of GT Conference 2017: Simulation Tool for Predictive Control ... · © FH AACHEN UNIVERSITY OF...