1. CO2 progress and issues on the control system Lukasz Zwalinski – PH/DT 13.04.2010

2. There will be one PCO with 3 option modes driven by allowance table Plant operation L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010 StopStand-ByRun Stopx1x Stand-By1x1 Run11x Switch between modes is executed manually by the operator request. Stop(Option Mode 1) All devices are in safety position. Stand-By(Option Mode 2) Operator can safely move system from “warm” environmental conditions to the state where accumulator is cooled down. Run(Option Mode 3) Run is defined as an option in which plant is fully operated and tested structure can be entered with certain inlet enthalpy. PCO is in run Order One PCO Alarm is blocked Push button to open sequencer panel PCO is in manual mode Current selected option mode

3. Plant operation In option mode Stand-By we can distinguish stepper with 4 steps associated 2 Start up 1 CO 2 PCO T2 Cool down loop Safety position 3 0 Cool down accumulator T3 T0 Start up request Cool down request Cool down accumulator request T1 T0 Safety position – It is preparation step before plant start up. Before first operation accumulator will be filled up to 75% of volume. This step in P-h diagram Fig.3 is somewhere along 22 0 C isotherm in the 2-phase region. Pump inlet temperature will be 22 0 C. Pump head and system pressure will be about 60 Bar. In this step all objects are switched off. Start up – accumulator is heated up to 27 0 C and the system pressure increase to the corresponding saturation pressure 67 bar. In the first stage of plant operation set-point selection has to be done manually by the operator. When this condition is fulfilled, loop should be filled with liquid and then pump might be manually switched on. The liquid level in accumulator will decrease. 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 CO 2 is out of the 2-phase region flowing sub-cooled liquid in to the pump. Cool down accumulator – starting the accumulator cooling spiral will drop the pressure and the liquid temperature to the desired set point. The vapor in the accumulator will condense; therefore the liquid level will start to increase. Transition conditions: T0 = Not Run Order OR Not Option Mode Stand-by T1 = Run Order & Option Mode Stand-by T2 = Run Order & Option Mode Stand-by & liq. circulation is achieved  Pump ON & FT1901 > 0.0 T3 = Run Order & Option Mode Stand-by & TT1110 – 3 0 C < TT sat (calculated from PT1104) L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010

4. PCO alarms PCO alarms: Start interlock: all requests are blocked when ON, prevents the object from starting SI1 – NOT Option Mode Selected; [0s delay] Temporary Stop interlock: sends OFF request to the object when ON (Resetting does not require the intervention of the operator If Run-order was active before interlock appear then after the elimination of interlock source Run-order becomes active automatically) TS1 – NOT 24V PS01 Status OK; [0s delay] Full Stop interlock: sends OFF request to the object & waits acknowledge when ON (Restarting requires the elimination of the interlock and the operator attending to do it. If Run-order was active before interlock appear then after the elimination of interlock source Run- order rest deactivated) Run-order – indicate that the object start is requested and there is no interlock. FS1 – NOT (Process Stop Button OK AND Process Stop OK); [0s delay] FS2 – Chiller Pressure Switch Low = 1 OR Pressure Switch High = 1 [0s delay] FS3 – Pump Thermal Switch TS1101 [5s delay] L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010

5. Accumulator Control PT1103 Acc. T sp PC1104 MV SP EH1104 Out High limit Out Low limit Low limit High limit 0% Dynamically calculated f(R th ) 0 ÷ 100 % PC1105 Out Low limit Out High limit MV SP P sat (Tsp) CV1104 Low limit High limit Dynamically calculated f(sub-cool) 0 ÷ -100 % 0% OutO IF Out1 + Out2 > 0 Then EH1104 Active Else CV1105 Active Analog Digital Object PWM 0 ÷100% PWM 0 ÷100% L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010

6. Accumulator Control calculated every 5s Thermal resistance: CO2_B158_PC1104minRth50 mK/W CO2_B158_PC1104maxRth75 mK/W CO2_B158_ PC1104OutHmin25 % CO2_B158_ PC1104OutHmax100 % subcool = T sat (PT1103) – TT1110 Sub cooling: CO2_B158_PC1401scH5 K CO2_B158_PC1401scL3 K CO2_B158_ PC1401OutLmin-10 % CO2_B158_ PC1401OutLmax-100 % L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010

7. Accumulator Control L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010

8. Logic STOP Stand-By Run Safty position Start-upCool down loop Cool down accumulator EH1101 Pump oil bathOFF Reg TT1101 SP= EH1102 DumperOFF Reg TT1102 SP = EH1104 AccumulatorOFF Reg PT1103 SP=27C Reg PT1103 EH1301 ChillerOFF ON EH1903 after supply/return HXOFF IF TT1103 -2 0 C ≤ T sat (PT1105) Positon request = (h requested - h 3 ) * Ø m CV1105OFF Reg PT1103 SP= PumpOFF IF TT1110 – 3C < TTsat(calculated from PT1104) THEN ON ChillerOFF Chiller = ON L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010

9. Enthalpy control Ø m = Q experimet / (h 5 - h 4 ) Q heater = (h requested - h 3 ) * Ø m It is not possible directly control the enthalpy in a PID loop. The enthalpy can be derived from measured pressure and temperature only when the state point is present in the liquid phase which means that measured temperature should be at least 2 0 C lower than calculated T sat. Because the enthalpy of point 3 and 3’ (Fig.3) can be in the 2-phase area calculation procedure have to use previous measurements from state point 2 (Fig3.). The PLC is calculating enthalpy from measured temperature TT1103 and pressure PT1105 and it’s on only if TT1103 -2 0 C ≤ T sat (PT1105) is true. L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010

10. UNICOS user interface L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010

11. 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 (98%) 5 – Code compilation 6 – Loading to PLC 7 – Commisionig & operation All generated files will be kept in Subversion Version Control (SVN) service. L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010

12. Log-in account to PC and PVSS L.Zwalinski – PH/DT CO2 test stand control system 12.04.2010 More topics to discus: common login to PC login to PVSS and privileges enthalpy search method (are there any formulas to calculate enthalpy form measured temperature and pressure or only NIST tables)