07_Dynamic_Plant_Simulation_T.pdf

7/29/2019 07_Dynamic_Plant_Simulation_T.pdf

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1 D. Krenz / HDB / z3641.ppt

Linde Engineering

Dynamic Plant Simulation

Tehran, September 26th 2005

Dieter Krenz

Linde Engineering


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Linde EngineeringThe plant control system, plant tuning,operator training and the plant operatingpoint influences the overall plant result

HYCO plants have different topology

Several feeds, fuel gases, parallel trains etc. A control system shouldmeet the special plant topology

The operator knowledge is the key for a smooth plant operation

Training of the operator is a precondition for a good plant operation

A plant consists of many valves and controller

Tuning of these control loops have a great impact on the dynamicplant behavior

The plant operating point is responsible for the plant profit

Changing feed situations can lead to different best plant operatingpoints


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Linde EngineeringLinde applies simulation for training,control system design, tuning andoptimization

Simulation models are used for

Training

Control system design

Tuning of PID controller and plant units

Automatic plant start up

Best plant operation


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Linde EngineeringDynamic simulation reducescommissioning time andminimizes trail and error

Advantages

tests and demonstration of plant behavior already before plantstart-up

time consuming tests with the real plant can be done much

faster with a dynamic simulation model

reduced test activities with the real plant during commissioning

Overall Benefit

reduced commissioning time less trail and error

Best operation point


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Linde EngineeringLinde uses commercially availablesimulation as well ascustomized simulations in Excel

The purpose of the simulation defines the simulation tool

Excel for simulations of HYCO plants (reformer, shift reaction,simplified cold box, etc.)

Commercially available simulation packages such as HYSYSare used for studies

Lindes simulation tool OPTISIM when the accuracy of

property data is significant (Cold Box)


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Linde Engineering

Linde set up the simulation in orderto give the customer a easy to use tool

The simulation set up with EXCEL is flexible and user friendly

The simulation model is tailored to the actual plant and includesonly the major mass and energy balance. No special knowledge

necessary to use the simulation model

Easy to use simulation model with a comprehensive user interfacewhich can be modified in the look and feel

Both dynamic and steady state models are available


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Linde Engineering

Simulation set up in HYSYS

5m3

6m3

6m3

60m3

5m3

5m3

320m3

5m3


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Linde EngineeringA dynamic simulation showsthe expected plant behaviorbefore commissioning

Feed

H2/CO

in OXO

OXO

H2

to Shift


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Linde Engineering

Simulation set up in EXCEL (partly)

13797.2kg/h 38.0bar

13788 kg/h 1.0bar

4415.6kg/h

50.0% 4413 kg/h 1.30bar

76.3%

3.56mol% ch4

6803.4kg/h 15.8% 29.55mol% H2O

6800 kg/h 1.36mol% 1.30bar 44.16mol% h2

2.75mol% 1025.9cel 14.67mol% CO

7.92mol% CO2

0.15mol% N2 875 cel

40.0bar 67.2% 28.6bar 26.6bar 874.0cel

600 cel

0.94828 ch4 397 cel 100.0% 9.03MW

0 H2O 29 bar co2 ref 1.0bar 250 cel

0.0291 h2 7959 kg/h

0 CO

0.000485 CO2 2.0kg/h

0 C2H4 7959 kg/h 70000.0kg/h

0.009457 C2H6 70000 kg/h

0.0006 C3H6 51.8% 60.7% 81.3% 0.0% 0.0% 0.0%

0.003301 C3H8

0 C4H8

0.000641 i-C4H100.000621 n-C4H10 0.0% 1452.3kg/h 757.3kg/h 1090.6kg/h 0.0kg/h 0.0kg/h 0.0kg/h

0.000214 C5H12 1463 kg/h 758 kg/h 1072 kg/h 0 kg/h 0 kg/h 0 kg/h

0.0000388 C6H14

0.007864 N2 0.0kg/h

-21 kg/h

40.0bar

v

Feed

1

v

v

reformer

steam

co2imp

v ng v pg v tg v h2 v co v co2

v

air

co2rec

mp

tc

v pcbox

prereformer

v st. pref


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Linde Engineering

Well trained operator makeless errors in plant operation

Class room training is organized in the steps

Definition of the training goals

Explanation and demonstration of the process basics

Group work with the aid of a training simulator

discussion


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Linde Engineering

Example of Linde class room trainingwith dynamic simulation

1const30000.0kg/h flow in

periode100.0sec 30000.0kg/h

amplitude FIN2500.0kg/h 50.0% SP3

29500.79950.0%

2 KP PV3 FOUT2

360 TI 30000.2kg/h0 TD

44.7% OP3

0

10

20

30

40

50

60

0 100 200 300 400

time

PV3,SP3andOP3

PV3

OP3

SP3

drum MAN

AUTO

LC1

v

LC1

const

sinus

flow in

27000

27500

28000

28500

29000

29500

30000

30500

31000

0 100 200 300 400

time

FIN2andFOUT2

FIN2

FOUT2


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Linde EngineeringOur HYCO plant control systemsare successfully used indifferent plant topologies

The frequent operation of a plant load change is done totally automaticby Lindes control system

The control system calculates all setpoints (flows, O2, steam,

feed etc.) based on simplified or rigorus models

The operator has only to enter the target values for the products

If one plant unit trips the rest of the plant remains running

Changes of heating values are compensated for in a special heatvalue loop


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Linde Engineering

RemoteSP =

33000 kg/h

RemoteSP =

132000 kg/h

TC

Reformer

FC

FC

PC

FCFC

NG = 1500 kg/hFeed =

15000 kg/h

RemoteSP =

45000 kg/h

RemoteSP =

15000 kg/h

SP

Load

Steam

Feed

Min

Steam

FC

Air = 132000 kg/h

RemoteSP =

1500 kg/h

air /

purge

air /

gas

Reformer Load And Fuel Gas Control Training

820.5 celInternalSP =

45000 kg/h

InternalSP =

15000 kg/h

Internal SP =1500 kg/h



START

Simulation

STOP

Simulation

AUTO

AUTO

AUTO AUTOAUTO

MAN

AI O2 = 2.4 %

Excess

Air

Min

Air

Purge = 33000 kg/h

Steam =

45000 kg/h

InternalSP =

45000 kg/h

InternalSP =

15000 kg/h

InternalSP =1500 kg/h



InternalSP =820.5 cel

Load

controldetails

Air/temp

control

details 14 3 1.10000 75000

80 3 25000

Feedforward

8

+

TC-Out =

0 kg/h

Init OFFHOLD

Simulation

help on

Example of a reformer control systemfor demonstration of principle controlsystem features


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Linde Engineering

Control and simulationof a standard H2 plant

Reformer CO shift PSAH2 ProductFeed

Plant topology:

Control system:Based on the target value for the H2 product the setpoints for steam,

feed, temperatures, O2 etc are calculated via feedforward andfeedback

Simulation:

Based on a simplified energy and mass balance there are steady stateand dynamic simulation available


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Linde Engineering

Control and simulation of a HYCO Plant

Reformer MDEA Adsorber Cold Box

PSA

CO Product

H2 Product

Feed

Plant topology:

Control system:

Based on the target values for the products H2 and COthe setpoints for steam, feed, temperatures, O2 aswell as the flows and temperature setpoints in thecold box are calculated via feedforward andfeedback

Simulation:Based on a simplified energy and mass balancethere are steady state and dynamic simulationavailable


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Linde Engineering

Plant topology:

Control system:

Based on the target values for the products H2and OXO the setpoints for steam, feed,temperatures, O2 MDEA cycle flows,membrane pressure etc are calculated via

feedforward and feedback

Simulation:

Load changes have been simulated in HYSYS

POX CO-Shift MDEA Membrane

PSA Compressor

cooling

OXO Product

H2 Product

Feed

Control and simulation of aHYCO Plant with POX and membrane


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Linde Engineering

Plant topology:

Control system:

Based on the target values for the products H2 and CO the load is automaticallydistributed to CO shift and cold box. The setpoints for steam, feed,temperatures and O2 as well as the flow and temperature setpoints in the

cold box are calculated via feedforward and feedback.

Simulation:

Steady state simulation

Reformer CO-Shift PSA

MDEA

CO Product

H2 ProductFeed

Cold Box

Control and simulation of aHYCO Plant with POX and membrane


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Linde Engineering

ProductsPlant

FI

Controller

for correction

+Calculation

of

Setpoints

for the

Plant

Setpoint

Products

MeasurementSetpoint

Feedforward

Independent Plant

inputs such as

Reformer Load

CO2 Recycle etc

Calculation of independent plant inputs such as reformer load etc. basedon operator setpoint for the products

adjustment of all significant controller as a function of plant load byfeedforward

deviations between setpoints for products and actual measured productsare compensated by a controller

A General load control conceptis applied to all plant topologies


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Linde Engineering

setpoint

syngas temperature

Controller settings are responsiblefor the plant dynamic

step response isunstable

step response isexcellent

step response is tooslow

Reformer

TC

Fuel gas

control

TimeTime Time


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Linde Engineering

setpoint

syngastemperature

A dynamic simulation of thecontrol loop leads to anexcellent behavior in a short time

step response isexcellent

Reformer

TC

Fuel gascontrolTime

dynamic simulation based onmeasurements

Leads to the best overallresponse with minimum workin the real plant and minimum

trail and error


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Linde Engineering

Model Identification by setting V, TS, TOT and/or KI

Model EquationY_MOD = V*(1 - exp(-(t-TOT)/TS)) + KI*(t-TOT)

V TS TZ KI Delta_U Abtastzeit

20 1250 240 0 1000 50

0

5

10

15

20

-10 -1 450 950 1450 1950 2450

0

200

400

600

800

1000

1200

Y_MES

Y_MOD

Delta_U

Go To Control Hilfe Einblenden

A two step procedure with Lindestuning programm leads to bestcontroller settings in minimum time

PID-CONTROLLER TUNING

Setpoint DisIn DisOut

10 PID-Controller Periodend.1000 Plant Periodend.100

KP = 1 Amplitude200.0 Vertrkung 20 Amplitude0.0

TN = 800 Anstiegszeit 1250

SP TD = 0 PlantIN= Totzeit 240 PlantOut

PID_OUT+DisIN Integrations. 0

PID_OUT HIGH / LOW PV HIGH LOW SCALING PV=PlantOut+DisOUT

MH=50000.0 -ML=50000.0 PVH=1000.0 PVL=0.0

Sim.-zeit

3600.0 sec

Abtastzei t

1.0 sec

Zufallssignal

-ZinMin=0.1

ZinMax=0.1

Kin=0.0

ZouMin=0.0

ZouMax=0.0

Kou=0.0

0

2

4

6

8

10

12

14

0 494.2 988.5 1482.7 1976.9 2471.2 2965.4 3459.6

-500

0

500

1000

1500

PlantOut

SP

DisOut

PlantIn

DisIn

Input PlantInput Plant Model

Hilfe Einblenden

Model identification based onplant measuremnts

Dynamic simulation of theclosed loop


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Linde EngineeringDynamic Simulation is usedfor tuning of complex systemssuch as a steam system

PC-hh

SGTCOND

SGTEXTR:

cond

HP Header

MP Header

LP Header

HP-steamreformer.

HP-steamsyngas cooler.

MP-steam

co shift.

FC

Dilution steamreformer PC

PC-h

Auxilaryboiler

SGC

loadcontrol

FC

LP export

PC-h

TG

COND

TG

EXTR:

cond

PC

G

Power

PC-hh

PC-hh PC

FI

FI


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Linde Engineering

Simulation set up of asteam system simulation


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Linde Engineering

An automatic plant start up / shut-down with the aid of a sequence.

A sequence itself will perform valve and/or controller open/close/rampingin the same way as described in the operating manual and

is organized in steps such as purging, heating, feed in etc.

Before the next step will be executed the previous one must be finishedsuccessfully. This is checked by comparing actual with expected operatingconditions.

In case of an error (failed check) the sequence will hold. The operator will fixthe problem and resume the sequence.

The operator can hold and resume the sequence at any time.

Automatic Plant Start Up


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Linde Engineering

A PFD serves as visualization of all stepsvalve open/close is indicated by green/red

actions are yellow with a descriptiontransitions are blue with a description

Automatic Plant Start Up


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Linde EngineeringA plant model enables the plant operatorto change major plant variables andverify the best operating point

Independent plantinputs such as feed

composition

Plant Model

Observation of thepredicted products and

selection of theoperating point which

promises the best plantresult

Variation of plantvariables such as

steam/feed, reformeroutlet temperature etc.


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Linde Engineering

Example for a HYCO plant modelfor the operating point calculation

O2 0.00%

AC2104 O2-SP

1.22mol% 1.22mol% 0.00%

0.00% 0 kg/h

0 kg/h flue gas H2-Product

steam T2118 0 kg/h

FC2106 987 cel 0 Nm3/h

0 kg/h 0.00% F. 0.0kmol/h

D/C 28.6bar 0 kg/h

3.00kg/kg 855 cel 330 cel 0.00%

reformer 0.00% 0.00% shift 0.0kmol/h psa

co2=0.00mol% co2=0.00mol%580 cel co2=0.00mol% co2=0.00mol%

0.00% co2=0.00mol% co2=0.00mol% purge gas

feed co2=0.00mol% T co2=0.00mol% 0 kg/h

0.0kmol/h 855 cel dry ch4 0.000mol

FC2103 dry h2o 0.000mol

0 kg/h 0.00% h2 0.000mol0 kg/h 0.00% co 0.000mol

0.00% air co2 0.000mol

0 kg/h n2 0.000mol

Einsatzzusammensetzung 250 cel

0 ch4 0 49.22MJ/kg 9.73MJ /k g FC2115

0 H2O 0 Erdgas DWA Restg 0 kg/h

0 h2 0 0 kg/h

0 CO 0

0 CO2 0 0 kg/h 0 kg/h

0 C2H4 0 FC2119 FC24030 C2H6 0 0 kg/h 0 kg/h

0 C3H6 0 0.00% 0.00%

0 C3H8 0

0 C4H8 00 i-C4H10 0

0 n-C4H10 0

0 C5H12 0

0 C6H14 0

0 N2 0.0082

1.00 1.00

combustion

steam

D/C

Steam or D/C

feed

Production

feed / Producti

ON (to flar)

OFF (no flare

purge gas to flare

Man Auto

o2

Man Auto

temperatur

NSG

RUG

Einsatztyp

M1

M2

M3 HG1 HG2

Heizgastyp

HG3 HG4 HG5

wie Einsatz

aus HG-Typ

Heizgaswahl

Man Auto

ch2.sp


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Linde EngineeringLindes simulation models are easyto use and lead always to a improvedand smooth plant operation

Simulation models are tailored to your plant can run on normal PChardware and can be used immediately without any programmingwork

The operator can learn with simulation models the process behaviorwithout endangering the real plant. The Excel models are especiallygood because of their user interface (similar to the DCS) and the lowinvestment coasts

The plant tuning is done with simulation models in order to reduce

trail and error. This results in best plant operation under changingplant conditions.


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Linde Engineering

Thank you for your Attention.

Documents

07_Dynamic_Plant_Simulation_T.pdf