co2 progress and issues on the control system lukasz zwalinski – ph/dt 09.02.2009

CO2progress and issues on the

control system

Lukasz Zwalinski – PH/DT09.02.2009

Requirements for test stand:• 32 Analog Inputs • 4 Analog Outputs• 32 Digital Inputs • 32 Digital Outputs• SCADA system with long term logging

Requirements for CO2 test stand

L.Zwalinski – PH/DT CO2 test stand control system 10.02.2010

There will be one PCO with 3 option modes driven by allowance table

Plant operation


Stop Stand-By Run

Stop x 1 0

Stand-By 1 x 1

Run 1 1 x

Switch between modes is executed manually by the operator request.

Start interlock: all requests are blocked when ON

SI1 – NO Option Mode Selected

Temporary Stop interlock: sends OFF request to the object when ON

TS1 – NO 24V PS01 Status OK; [10s delay] Full Stop interlock: sends OFF request to the object & waits acknowledge when ON

FS1 – NO Process Stop Button OK OR NO Process Stop OK; [2s delay] FS2 – HPC Pressure Switch Low =1 OR Pressure Switch High =1 [5s delay] FS3 – Pump Thermal Switch TSL1101 [5s delay]

Configuration logic:FeedBackON = True IF CO2 PCO (Run Order & One of the option modes selected) FeedBackOFF = False IF NO CO2 PCO (Run Order & One of the option modes selected)

CO2 PCO

Plant operation


2

Start up1

CO2 PCO

T1

Cool down loop

Safety position

3

0

Cool down accumulator

T2

T0

T0

T0

Start up request

Cool down request

Cool down accumulator request

In option mode Stand-By we can distinguish stepper with 4 steps associated

Safety position It is preparation step before plant start up. All objects are switched off.

Start up Accumulator is heated up to 27C.

When TRUE loop should be filled with liquid and then pump might be switched on.

Cool down loop Once liquid circulation is achieved chiller might be switched on.

Accumulator is still kept at high pressure and the condenser will sub-cool the liquid.

This is important to assure that CO2 is out of the 2-phase region flowing sub-cooled liquid in to the pump.

Cool down accumulator starting the accumulator cooling spiral

Transition conditions:

T0 = Not Run Order OR Not Option Mode Stand-by

T1 = Run Order & Option Mode Stand-by & liquid circulation is achieved Pump ON & FT1901

> xx

T2 = Run Order & Option Mode Stand-by & TT1110 – 30C < TTsat(calculated from PT1104)

Accumulator Control

PT1103

Acc. Tsp

PIDMV

SPEH1104

Out High limit

Out Low limit Low limit

High limit

0%

Dynamically calculated f(Rth)0 ÷ 100 %

PID

Out Low limit

Out High limitMV

SP

Psat(Tsp)

CV1104

Low limit

High limit

Dynamically calculated f(sub-cool)0 ÷ -100 %

0%

OutO

OutO

IF > 0 Then EH ONELSE OFF

IF < 0 Then CV ONELSE OFF

Analog Digital Object

Analog Object

PWM

0÷100%

PWM

0÷100%


Accumulator Control

Power

TTR accuheaterth

calculated every 5s

Thermal resistance:

thth

ththnew RR

OutHOutHRROutHOutH

minmax

)(*max minmaxmin

CO2_B158_PC1104minRth 50 mK/WCO2_B158_PC1104maxRth 75 mK/WCO2_B158_ PC1104OutHmin 25 %CO2_B158_ PC1104OutHmax

100 %

subcool = Tsat(PT1103) – TT1110

Sub cooling:

LH

Lnew subcoolsubcool

OutLOutLsubcoolsubcoolOutLOutL

)(* minmax

min

CO2_B158_PC1401scH 5 K

CO2_B158_PC1401scL 3 K

CO2_B158_ PC1401OutLmin -10 %

CO2_B158_ PC1401OutLmax -100 %


Interlocks

Pump_ST1 IF TT1101 > ? oC Then Pump OFF

Pump_ST2 IF CB_Pump_OK = FALSE Then Pump OFF

HPC_ST1 IF TT1110 < -55oC Then HPC OFF

HPC_ST2 IF (PSL OR PSH) = TRUE Then HPC OFF

HPC_ST3 IF CB_HPC_OK = FALSE Then HPC OFF

EHHPC_ST1 IF CB_EHHPC_OK = FALSE Then EHHPC OFF

EHHPC_ST2 IF HPC.OffST = TRUE Then EHHPC OFF ????

EH1101_ST1 IF CB_EH_OK = FALSE Then Heater OFF

EH1101_ST2 IF TT1101 > threshold Then Heater OFF


EH1102_ST2 IF TT1102 > threshold Then Heater OFF

EH1102_ST3 IF TS = 1 Then Heater OFF


EH1903_ST2 IF TT11## > threshold Then Heater OFF


logic


STOPSafty

positionStart-up Cool down loop

Cool down accumulator

Run

EH1101 Pump oil bath OFF OFF Reg TT1101 SP= Reg TT1101 SP= Reg TT1101 SP= Reg TT1101 SP=

EH1102 Dumper OFF OFF Reg TT1102 SP = Reg TT1102 SP = Reg TT1102 SP = Reg TT1102 SP =

EH1104 Accumulator OFF OFFReg PT1103

SP=27CReg PT1103

SP=27COFF OFF

EH1301 Chiller OFF OFF OFF ON ON ON

EH1903 after supply/return HX OFF OFF OFF OFF OFF

IF TT1103 -20C ≤ Tsat(PT1105) AND Manual On Request

= True THEN EH1903 = ON

EH1903.AuPosR (Positon request =

power) (hrequested - h3) * Øm

CV1104 OFF OFF OFF OFF Reg PT1103 SP= Reg PT1103 SP=

Pump OFF OFF OFF

IF TT1110 – 3C < TTsat(calculated

from PT1104) THEN ON





Chiller OFF OFF OFF

IF TT1110 ≥ -55C Then Chiller = ON Else Chiller = OFF

IF TT1110 ≥ -55C Then Chiller = ON Else Chiller = OFF

IF TT1110 ≥ -55C Then Chiller = ON

Else Chiller = OFF

Enthalpy control

Øm = Qexperimet / (h5 - h4)

561 4

2 3

Enthalpy (kJ/kg)

Qheater = (hrequested - h3) * Øm

•It is not possible directly control the enthalpy in a PID loop.

•The enthalpy must be derived from measured pressure and temperature and always be present in the liquid phase which means that measured temperature should be at least 2C lower than calculated Tsat. IF TT1103 -2C ≤ Tsat(PT1105) THEN enthalpy calculation ON

•The enthalpy of point 3 can also be in the 2-phase area

• The PLC is calculating enthalpy of a point 2 from measured temperature (TT1103) and pressure (PT1105).

Tsat = B / [ln(P)-A]-C A = 10.77 B = -1956 C = 271.04


UNICOS user interface


Software preparation

SCADA server

Logic Generator

Instance Generator

Specyfication

SIEMENS PLC

UNICOS project creation:

1 – Exel specyfication preparation

2 – PLC hardware configuration

3 – PLC & PVSS instance generation

4 – Process logic programation

5 – Code compilation

6 – Loading to PLC

7 – Commisionig & operation

All generated files will be kept in Subversion Version Control (SVN) service.


co2 progress and issues on the control system lukasz zwalinski – ph/dt 09.02.2009

Documents

co2 test standl

run order option mode

st2if hpc

st2if cb

st1if cb

pump offhpc

heater offeh1102

button ok