Final Presentation

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TRAINING ON NEW GAS STATION CONTROL SYSTEMS, INSTRUMENTATION AND DETECTION SYSTEMS

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Final Presentation

  1. 1. NEFT DASHLARI GCSII <ul><li>TRAINING ON NEW GAS STATION CONTROL SYSTEMS, INSTRUMENTATION AND DETECTION SYSTEMS </li></ul>
  2. 2. PRESENTATION <ul><li>SPEACHER: Mandarini Salvatore </li></ul><ul><li>COMPANY: RENCO </li></ul><ul><li>visit our web site. www.renco.it </li></ul>
  3. 3. PRESENTATION <ul><li>SPEACHER: Mandarini Salvatore </li></ul><ul><li>COMPANY: RENCO </li></ul><ul><li>visit our web site. www.renco.it </li></ul>
  4. 4. ACRONYMS <ul><ul><li>DCS: Distribute Control System; </li></ul></ul><ul><ul><li>ESD: Emergency Shut Down; </li></ul></ul><ul><ul><li>SDV: Shut Down Valve; </li></ul></ul><ul><ul><li>BDV: Blow Down Valve; </li></ul></ul>
  5. 5. MAIN PROCESS DATA <ul><ul><li>Gas Flow: 3.6 MM Scm/day: </li></ul></ul><ul><ul><li>Pressure: </li></ul></ul><ul><ul><ul><li>Inlet: 4,5-6 bara; </li></ul></ul></ul><ul><ul><ul><li>Outlet: 35-58 bara. </li></ul></ul></ul><ul><ul><li>Temperature: </li></ul></ul><ul><ul><ul><li>Inlet: 5-25 °C; </li></ul></ul></ul><ul><ul><ul><li>Outlet: ~ 45°C. </li></ul></ul></ul><ul><ul><li>Water content. </li></ul></ul><ul><ul><ul><li>Inlet: 0,4 g/Scm; </li></ul></ul></ul><ul><ul><ul><li>Outlet: Water dew point -5°C @ 58 bar. </li></ul></ul></ul>
  6. 6. DCS SUB -SYSTEMS <ul><li>The compressor station is divided is Subsystems: </li></ul><ul><ul><li>Sub-system Main Headers </li></ul></ul><ul><ul><li>Sub-system HP Fuel Gas Header </li></ul></ul><ul><ul><li>Sub-systems Fuel Gas HP, LP </li></ul></ul><ul><ul><li>Sub-system Seal Gas HP, LP </li></ul></ul><ul><ul><li>Sub-system Turbines HP. LP </li></ul></ul><ul><ul><li>Sub-system Glycol Regeneration System </li></ul></ul><ul><ul><li>Sub-system Glycol Regeneration Utility System </li></ul></ul>
  7. 7. DCS SYSTEM <ul><li>The Compressor Station can be controlled in the Following Way: </li></ul><ul><li>Semiautomatic; (Professional User) </li></ul><ul><ul><li>Automatic; (Basic User) </li></ul></ul><ul><ul><li>Manual; (Professional User) </li></ul></ul>
  8. 8. <ul><ul><li>In semi automatic operating mode the operator can leads the single sub system status in a defined state. </li></ul></ul><ul><ul><li>Each “Sub-system” is controlled by “ PROCEDURE”. In Semiautomatic operating mode Static and Dynamic procedure of sub </li></ul></ul><ul><ul><li>systems involved are executed by DCS Control system. </li></ul></ul><ul><ul><li>The sub system dynamic states represent transitions between two static states of the same sub system. </li></ul></ul><ul><ul><li>During the execution of Dynamic Procedure commands and check up are carried out sequentially by DCS Control system. </li></ul></ul><ul><ul><li>During the execution of Static Procedure conditions are continuously checked up by DCS Control system. </li></ul></ul><ul><ul><li>Closing and Opening valves commands are not enabled on valves faceplate if the relative subsystem is in Semi automatic </li></ul></ul><ul><ul><li>operating mode and only the “CASCATE” valves operating mode on faceplate is active. </li></ul></ul>SEMIAUTOMATIC: (PROFESSIONAL USER)
  9. 9. TRANSITION RULES BETWEEN STATES <ul><ul><li>The gas compression plant is decomposed in several sub-systems </li></ul></ul><ul><ul><li>and at any sub systems is associated a state variable that </li></ul></ul><ul><ul><li>defines the current condition. </li></ul></ul><ul><ul><li>DCS has to check the operator request to switch from a state </li></ul></ul><ul><ul><li>to another. </li></ul></ul><ul><ul><li>Not all states are reachable starting from a generic state. </li></ul></ul><ul><ul><li>At the beginning of each procedure in order to allow the </li></ul></ul><ul><ul><li>requested transition the actual state check up shall be carried </li></ul></ul><ul><ul><li>out. </li></ul></ul><ul><ul><li>At the end of each procedure the system will provide to update </li></ul></ul><ul><ul><li>the value of state variable of process sub system. </li></ul></ul><ul><ul><li>The process sub-systems can be in Unknown state: </li></ul></ul><ul><ul><ul><ul><li>UNKNOWN: Dynamic state generated by a </li></ul></ul></ul></ul><ul><ul><ul><ul><li>TIMEOUT or an ERROR. </li></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><li>UNKNOWN state is reachable starting from each </li></ul></ul></ul></ul><ul><ul><ul><ul><li>state in presence of TIMEOUT/ERRORS. </li></ul></ul></ul></ul><ul><ul><li>At the end of each procedure the system will provide to </li></ul></ul><ul><ul><li>update the value of state variable of process sub-system. </li></ul></ul><ul><ul><li>When the sub-system state is UNKNOWN all the alarms are </li></ul></ul><ul><ul><li>armed. </li></ul></ul><ul><ul><li>Hysteresis is necessary to avoid continuous changeover. </li></ul></ul>
  10. 10. <ul><ul><li>ABORT: In case of abnormal exit from an automatic procedure (abort) the state variable shall be set to </li></ul></ul><ul><ul><li>the previous static status (the value of the state variable had at the beginning of the dynamic procedure </li></ul></ul><ul><ul><li>itself) </li></ul></ul><ul><ul><li>ERROR: In case of a malfunction of the system response is detected, an error state is generated. </li></ul></ul><ul><ul><li>ALARM ONLY: The signals that generate this effect, does not affect the proceeding of the sequence. </li></ul></ul><ul><ul><li>CALL: Sequence Jump to another dynamic procedure of the same sub-system. </li></ul></ul>KEYWORDS
  11. 11. <ul><ul><li>When a step of dynamic transition can't finish within a determinate time interval (TIMEOUT), or an </li></ul></ul><ul><ul><li>ERROR occurred, DCS produces an interrupt with indications of the cause and gives choice to the operator </li></ul></ul><ul><ul><li>to change the status to UNKNOWN or to force the process system in SAFETY CONDITION. </li></ul></ul><ul><ul><li>The Safety Condition of process sub-system is the final condition of the automatic safety procedures. </li></ul></ul><ul><ul><li>When the state is UNKNOWN or the control mode is MANUAL, the DCS tries continuously to recognize </li></ul></ul><ul><ul><li>the new status (one of the defined static states). </li></ul></ul><ul><ul><li>If this is possible the UNKNOWN status changes to the recognized one. </li></ul></ul><ul><ul><li>Operator can understand what forbid the status recognition looking at Status Table. </li></ul></ul><ul><ul><li>Status Table is a graphic page where, for each automatic procedure and for each relevant static status, </li></ul></ul><ul><ul><li>are listed the involved conditions with a back color associated: red when the condition is unsatisfied, green </li></ul></ul><ul><ul><li>otherwise. </li></ul></ul>TIME OUT/ERROR
  12. 12. State Recognized Procedure <ul><ul><li>In normal plant working conditions (automatic or Semi automatic operation mode), SRP is disabled for process </li></ul></ul><ul><ul><li>sub-plant that are on dynamic state and activated for process sub-plant that are in static state. </li></ul></ul><ul><ul><li>For last cases, SRP checks the setting of the process sub-plant and in case the state doesn’t recognized, </li></ul></ul><ul><ul><li>the state variable is set to UNKNOWN. </li></ul></ul><ul><ul><li>The “known state” lost may be caused by an operator manual interventions and/or ESD interventions and/or </li></ul></ul><ul><ul><li>faults and/or loosing of signals that identify a static state (Static state not recognized) </li></ul></ul><ul><ul><li>ESD interrupt, are “unforeseen events”. </li></ul></ul><ul><ul><li>Dynamic procedures in Semi automatic mode will be available again only for those process sub-plant which </li></ul></ul><ul><ul><li>have the state variable different to UNKNOWN; </li></ul></ul><ul><ul><li>An exception at this rule is for the dynamic procedures which bring the process sub-plant in safety condition </li></ul></ul><ul><ul><li>(DEPRESSURIZATION, STOPPING, COLD CATCH). </li></ul></ul><ul><ul><li>These dynamic procedure in Semi automatic mode must be reacheble from any state and must be execute in </li></ul></ul><ul><ul><li>any case, independently from process sub-system state (unconditional procedures). </li></ul></ul>
  13. 13. State Recognized Matrix <ul><ul><li>State Recognized Matrix shows, for any process sub-plant, all possible Static States in relationship with main items. </li></ul></ul><ul><ul><li>Any row contains, then, necessary and sufficient conditions in order that a specific state may be recognized. </li></ul></ul><ul><ul><li>In case that a condition is insignificant for state recognized, this will be marked with “ / “. </li></ul></ul><ul><ul><li>The SRP, starting from the first row, has to execute all the check list in the column and compare the result with the relative value; </li></ul></ul><ul><ul><li>In case the check of ALL conditions is true the state associated to the row is set like current sub-plant state. </li></ul></ul><ul><ul><li>In case the check is false, next row will be examined. </li></ul></ul><ul><ul><li>If any state is recognized, at the end of the loop, state variable of process sub-plant will be set as UNKNOWN. </li></ul></ul>
  14. 14. VENT MONITORING <ul><ul><li>If manual mode is requested by operator when process sub-system is in pressurized state, it is possible that a vent line is opened by operator for some time and the pressure falls near atmospheric value. </li></ul></ul><ul><ul><li>If, after that, the operator closes the vent valve and pressurizes the sub-system again without purging it, the process fluid may be contaminated. </li></ul></ul><ul><ul><li>When the auto mode will be selected again the control system has no information about this circumstance. </li></ul></ul><ul><ul><li>To avoid this shall be define a new variable/flag VENT_MONITORING used for monitoring the situation described. </li></ul></ul><ul><ul><li>This variable is SET during the PRESSURIZATION and RESET if the pressure fall bellow a minimum value. </li></ul></ul><ul><ul><li>However it shall be possible for the operator to force VENT_MONITORING STATUS by a dedicated push button in manual mode. </li></ul></ul>
  15. 15. <ul><ul><li>The “VENT MONITORING” procedure is &quot;always running&quot;. </li></ul></ul><ul><ul><li>It means these procedures run in parallel mode to all the other ones foreseen for this plant sub-system, even when manual mode is selected. </li></ul></ul><ul><ul><li>Obviously automatic procedures are written so that no mismatch can happen with the always running procedures. </li></ul></ul>ALWAYS RUNNING PROCEDURES
  16. 16. EMERGENCY <ul><ul><li>During normal operation the DCS takes the control of SDV/BDV valves and all equipments. </li></ul></ul><ul><ul><li>When a cause of Emergency shutdown is activated the ESD system take the control of some shutdown/ blow down valves and equipment. </li></ul></ul><ul><ul><li>When the ESD action is terminated the DCS tries to recognize the new status (one of the defined static states). </li></ul></ul><ul><ul><li>If this is possible the UNKNOWN status changes to the recognized one, otherwise an alert message is sent to operator. </li></ul></ul>
  17. 17. HP FUEL GAS HEADER SUB-SYSTEM <ul><ul><li>The process sub-system can be in Depressurization state: </li></ul></ul><ul><ul><ul><ul><li>DEPRESSURIZATION: Dynamic state which allows to vent process fluid. </li></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><li>DEPRESSURIZATION dynamic state allows the transition from any state to DEPRESSURIZED. </li></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to DEPRESSURIZED status during the execution of DEPRESSURIZATION procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Turbine LP A,B – HP A,B Seal Gas sub systems shall be isolated and inlet valves “SDV – 3X50“ shall be closed.. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas sub system inlet valve “SDV – 3140“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas sub system vent valve “BDV – 3139“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>TIMEOUT shall be expired. </li></ul></ul></ul></ul></ul>
  18. 19. HP FUEL GAS HEADER SUB-SYSTEM <ul><ul><li>The process sub-system can be in Depressurized state: </li></ul></ul><ul><ul><ul><ul><li>DEPRESSURIZED: Static state with inlet HP fuel valve closed and vent line open. </li></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><li>DEPRESSURIZED state can be achieved by completing the procedure of DEPRESSURIZATION. </li></ul></ul></ul></ul><ul><ul><li>SAFETY CONDITION of process sub-system, that represents the final condition of automatic protection </li></ul></ul><ul><ul><li>procedures, coincides with DEPRESSURIZED state. </li></ul></ul><ul><ul><li>In order to maintain the DEPRESSURIZED SUB SYSTEM status essentially the following conditions shall be verified : </li></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas sub system inlet valve “SDV – 3140“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas sub system vent valve “BDV – 3139“ shall be open. </li></ul></ul></ul></ul></ul>
  19. 20. HP FUEL GAS HEADER SUB-SYSTEM <ul><ul><li>The process sub-system can be in Pressurization state: </li></ul></ul><ul><ul><ul><ul><li>PRESSURIZATION: Dynamic state which allows the purging of trapped air and the pressurization of process sub-system. </li></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><li>PRESSURIZATION dynamic state allows the transition from DEPRESSURIZED to PRESSURIZED. </li></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to PRESSURIZED status during the execution of PRESSURIZATION procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Pipeline pressure “PIT-3134” shall be above the set point.. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>VBD10-3137 shall be open and operator shall confirm it.. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas sub system inlet valve “SDV – 3140“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas purging shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas sub system vent valve “BDV – 3139“ shall be closed when purging TIMEOUT is expired. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Vent_Monitoring_3 variable status shall be set. </li></ul></ul></ul></ul></ul>
  20. 21. <ul><ul><li>The “VENT MONITORING” procedure is &quot;always running“ and if the conditions showed hereafter are </li></ul></ul><ul><ul><li>verified during its execution a Vent_Monitoring_3 variable reset shall be carried out to avoid a process </li></ul></ul><ul><ul><li>fluid contamination: </li></ul></ul><ul><ul><ul><ul><li>HP Fuel Gas sub system inlet valve “BDV – 3139“ is open & HP Fuel Gas sub system inlet valve </li></ul></ul></ul></ul><ul><ul><ul><ul><li>“ SDV – 3140“ is closed. </li></ul></ul></ul></ul><ul><ul><li>In case the operator is operating in manual mode it shall be possible for the operator to force </li></ul></ul><ul><ul><li>VENT_MONITORING_3 STATUS by a dedicated push button which is active / inactive whether all HP </li></ul></ul><ul><ul><li>Fuel gas header sub-system vent monitoring conditions are verified. </li></ul></ul>HP FUEL GAS HEADER SUB-SYSTEM
  21. 24. HP FUEL GAS HEADER SUB-SYSTEM <ul><ul><li>The process sub-system can be in Pressurized state: </li></ul></ul><ul><ul><ul><ul><li>PRESSURIZED: Static state with inlet HP fuel valve open and vent line closed. </li></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><li>PRESSURIZED state can be achieved by completing the procedure PRESSURIZATION. </li></ul></ul></ul></ul><ul><ul><li>In order to maintain the PRESSURIZED SUB SYSTEM status essentially the following conditions shall be verified : </li></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas sub system inlet valve “SDV – 3140“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas sub system vent valve “BDV – 3139“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Pipeline pressure “PIT-3134” shall be above the set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Vent_Monitoring_3 variable status shall be set. </li></ul></ul></ul></ul></ul>
  22. 25. HP FUEL GAS HEADER SUBSYSTEM <ul><ul><li>EMERGENCY </li></ul></ul><ul><ul><li>If the ESD system force the SHUTDOWN of SDV-3140 or BDV-3139 the state variable of the HP Fuel Gas </li></ul></ul><ul><ul><li>Header sub-system that control the valves above mentioned and equipment shall be changed to UNKNOWN by </li></ul></ul><ul><ul><li>means of the state RECOGNITION procedure. </li></ul></ul>
  23. 26. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Depressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZZATION dynamic state which leads to STOPPED PRESSURIZED state. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>This state can be always achieved from all the states on the request of operator. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZATION dynamic state allows the transition from any state to STOPPED </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZED. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to STOP DEPRESSURIZED status during the execution of </li></ul></ul><ul><ul><li>DEPRESSURIZATION procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system inlet valves “SDV – 3X30“ & “SDV – 3X31“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system vent valve “BDV – 3X40“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3X30” shall be below the set point. </li></ul></ul></ul></ul></ul>
  24. 28. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Stopped Depressurized state: </li></ul></ul><ul><ul><ul><ul><ul><li>STOPPED DEPRESSURIZED: turbine stopped, SDVs inlet valves “SDV – 3X30“ & “SDV – 3X31“ </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>closed, vent line “BDV – 3X40“ valves opened. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>STOPPED DEPRESSURIZED state can be achieved by completing the procedure of </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZATION. </li></ul></ul></ul></ul></ul><ul><ul><li>The SAFETY CONDITION of process sub-system corresponds to the STOPPED DEPRESSURIZED state. </li></ul></ul><ul><ul><li>In order to maintain the STOP DEPRESSURIZED SUB SYSTEM status essentially the following conditions shall be verified: </li></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system inlet valves “SDV – 3X30“ & “SDV – 3X31“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system vent valves “BDV – 3X40“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3X30” shall be below the set point. </li></ul></ul></ul></ul></ul>
  25. 29. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Pressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZATION: dynamic state with delivery valves “SDV – 3X30“ open and vent line “BDV – 3X40“ valves </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>before open (purging) and after closed. It leads to STOPPED PRESSURIZED state. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZATION dynamic state allows the transition from STOPPED DEPRESSURIZED to STOPPED </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZED. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to STOP PRESSURIZED status during the execution of PRESSURIZATION </li></ul></ul><ul><ul><li>procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Manual valves “VBD10-3X10” & “ VBB70” shall be open and operator shall confirm it.. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas Header conditions showed hereafter in State Recognized matrix shall be verified.. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>At the beginning Fuel Gas sub system inlet valve “SDV – 3X30“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas purging shall be carried out . </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas vent valve “BDV – 3X40“ shall be closed when the purging TIMEOUT is expired. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3X30” shall be above the set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Vent_Monitoring_1 variable status shall be set. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system inlet valve “SDV – 3X30“ shall be closed. </li></ul></ul></ul></ul></ul>
  26. 31. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>The “VENT MONITORING” procedure is &quot;always running“ and if the conditions showed hereafter are verified during its execution a Vent_Monitoring_1 variable reset shall be carried out to avoid a process fluid contamination : </li></ul></ul><ul><ul><ul><ul><li>Fuel Gas process sub plant pressure “PIT – 3X30“ is below the threshold. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Fuel Gas sub system inlet valve “SDV – 3X30“ is open & Hp Fuel Gas Header sub system is not purged ( VENT_MONITORING_3 shall be reset ). </li></ul></ul></ul></ul><ul><ul><li>In case the operator is operating in manual mode it shall be possible for the operator to force VENT_MONITORING_1 STATUS by a dedicated push button which is active / inactive whether all Fuel gas header sub-system vent monitoring conditions are verified. </li></ul></ul>
  27. 32. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Stopped Pressurized state: </li></ul></ul><ul><ul><ul><ul><ul><li>STOPPED PRESSURIZED: turbine stopped, SDVs inlet valves “SDV – 3X30“ & “SDV – 3X31“ closed, vent line </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>valve “BDV – 3X40“ closed. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>STOPPED PRESSURIZED state can be achieved by completing the procedures of STOPPING or </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZATION. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the STOPPED PRESSURIZED SUB SYSTEM status essentially the following conditions shall be verified : </li></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system inlet valves “SDV – 3X30“ & “SDV – 3X31“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system vent valve “BDV – 3X40“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Vent_Monitoring_1 variable status shall be set. </li></ul></ul></ul></ul></ul>
  28. 34. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Starting state: </li></ul></ul><ul><ul><ul><ul><ul><li>STARTING: dynamic state whom leads to RUN HP/HL state. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>STARTING dynamic state allows the transition from STOPPED PRESSURIZED to RUN HP/LP. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to RUN HP or RUN LP during the execution of START procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>If LP Fuel Gas Header conditions showed hereafter in State Recognized matrix are verified Fuel Gas sub system inlet valve “SDV – 3X31“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If the conditions regarding LP Fuel Gas Header are not verified HP Fuel Gas Header conditions showed hereafter in State Recognized matrix shall be verified & Fuel Gas sub system inlet valve “SDV – 3X30“ shall be open.. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3X30” shall be above the set point. </li></ul></ul></ul></ul></ul>
  29. 35. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Run HP state: </li></ul></ul><ul><ul><ul><ul><ul><li>RUN HP: operating functioning with gas feeding from the H.P. FUEL GAS HEADER. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>RUN HP can be achieved by completing the procedures of STARTING or SWITCHING. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the RUN HP SUB SYSTEM status essentially the following conditions shall be verified: </li></ul></ul><ul><ul><ul><ul><ul><li>Vent_Monitoring_1 variable status shall be set. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Pipeline pressure “PIT-3X30” shall be above the set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system vent valve “BDV – 3X40“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system inlet valve “SDV – 3X31“ shall be closed and “SDV – 3X30“ valve shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If LP Fuel Gas Header conditions showed hereafter in State Recognized matrix are verified a calling to </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>SWITCHING procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If the conditions regarding LP Fuel Gas Header are not verified, HP Fuel Gas Header conditions showed </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>hereafter in State Recognized matrix shall be verified & Fuel Gas sub system inlet valve “SDV – 3X30“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Turbine actual speed shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>TRIGGER_x variable status shall be set if the Turbine actual speed is higher than set point. </li></ul></ul></ul></ul></ul>HP
  30. 36. <ul><ul><li>The process sub-system can be in Run LP state: </li></ul></ul><ul><ul><ul><ul><ul><li>RUN LP: operating functioning with gas feeding from the L.P. FUEL GAS HEADER. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>RUN LP can be achieved by completing the procedures of STARTING or SWITCHING. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the RUN LP SUB SYSTEM status essentially the following conditions shall be verified : </li></ul></ul><ul><ul><ul><ul><ul><li>Vent_Monitoring_1 variable status shall be set. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Pipeline pressure “PIT-31X4” shall be above the set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system vent valve “BDV – 3X40“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fuel Gas sub system inlet valve “SDV – 3X31“ shall be open and “SDV – 3X30“ valve shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If the conditions regarding LP Fuel Gas Header are NOT verified, HP Fuel Gas Header conditions showed hereafter in State Recognized matrix shall be verified and a calling to SWITCHING procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Turbine actual speed shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>TRIGGER_x variable status shall be set if Turbine actual speed is higher than set point. </li></ul></ul></ul></ul></ul>FUEL GAS HP, LP SUBSYSTEMS LP
  31. 37. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>The timer T91 is the maximum time that the fuel gas system can operate in RUN status with the Turbine stopped. </li></ul></ul><ul><ul><li>If the timer T91 expires the Fuel Gas status is forced to STOP immediately. </li></ul></ul><ul><ul><li>The flag named TRIGGER_x is set when the turbine is started ; from this time, the timer has no effect, and if again </li></ul></ul><ul><ul><li>the turbine is stopped, the fuel gas system is forced to STOPPING immediately. </li></ul></ul><ul><ul><li>The flag TRIGGER_x shall be reset automatically if the state is not RUN or UNKNOWN. </li></ul></ul><ul><ul><li>To avoid the risk to close the fuel gas while the turbine is running, if a turbine speed state is not defined (serial link in </li></ul></ul><ul><ul><li>bad status) the trigger function is disabled. </li></ul></ul>HP
  32. 38. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>SWITCHING PROCEDURE </li></ul></ul><ul><ul><li>The process sub-system can be in Run HP state: </li></ul></ul><ul><ul><ul><ul><li>SWITCHING: dynamic state which leads from RUN_HP state to RUN_LP state and vice versa. </li></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><li>SWITCHING procedure allow transition from RUN HP to RUN LP (and vice versa) according to process </li></ul></ul></ul></ul><ul><ul><ul><ul><li>conditions. When it is possible the system give the preference to RUN_LP mode. </li></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to RUN HP or RUN LP during the execution of Switching procedure essentially </li></ul></ul><ul><ul><li>the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Every time a switching procedure calling is carried out when HP Fuel Gas sub system actual status is RUN </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>HP the HP Fuel Gas sub system inlet valve “SDV – 3X31“ shall be open & the HP Fuel Gas sub system inlet </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>valve “SDV – 3X30“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Every time a switching procedure calling is carried out when HP Fuel Gas sub system actual status is RUN </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>LP the HP Fuel Gas sub system inlet valve “SDV – 3X30“ shall be open & the HP Fuel Gas sub system inlet </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>valve “SDV – 3X31“ shall be closed. </li></ul></ul></ul></ul></ul>
  33. 39. RUN HP
  34. 40. RUN LP
  35. 41. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Stop state: </li></ul></ul><ul><ul><ul><ul><li>STOPPING: dynamic state whom leads to STOPPED PRESSURIZED state. </li></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><li>STOPPING dynamic state allows the transition from RUN LP/HP to STOPPED PRESSURIZED. </li></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to STOP PRESSURIZED during the execution of STOP procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><li>Fuel Gas sub system inlet valves “SDV – 3X30“ & “SDV – 3X31“ shall be closed. </li></ul></ul></ul>
  36. 43. <ul><ul><li>LP FUEL SELECTOR </li></ul></ul><ul><ul><li>A SOFTWARE SELECTOR always active is foreseen that enable/disable the automatic switching from RUN_HP to RUN_LP operations when the operator push the button showed hereafter. </li></ul></ul><ul><ul><li>If the selector is disabled by means the operator when the operation is just in RUN_LP mode, the transition to RUN_HP mode is forced. </li></ul></ul><ul><ul><li>Furthermore when the selector is disable by means the operator the STARTING operation will be performed only by using HP fuel gas header. </li></ul></ul>FUEL GAS HP, LP SUBSYSTEMS
  37. 44. ELECTRIC FUEL GAS HEATER <ul><ul><li>A stand alone procedure manages the fuel gas heater. </li></ul></ul><ul><ul><li>When the LOCAL/REMOTE switch of the Heater Control Panel is in LOCAL, an alarm shall be generated, the TIC controller shall be disabled and the ON/OFF command to the heater shall be in OFF state. </li></ul></ul><ul><ul><li>When the LOCAL/REMOTE switch of the Heater Control Panel is in REMOTE position, the fuel gas heater shall be started if the following conditions are satisfied: </li></ul></ul><ul><ul><ul><ul><ul><li>Fuel gas flow rate “FT-3X14” shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>One of the SDV-3X30 and SDV-3X31 valves shall be open or both valves shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The set point of electric fuel gas heater depends on the SDV valve opened: the higher set point is </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>related to SDV-3931 opened. </li></ul></ul></ul></ul></ul><ul><ul><li>If there is a switching between the SDV valves the set point changes accordingly. </li></ul></ul>
  38. 45. ELECTRIC FUEL GAS HEATER <ul><ul><li>When the LOCAL/REMOTE switch of the Heater Control Panel is in LOCAL or Heater Control Panel is switched off the TIC controller AUTO or CASCATE operating mode shall be disabled and the TIC controller MANUAL operating mode shall be enable. </li></ul></ul><ul><ul><li>In Manual MODE the operator can change the controller output. </li></ul></ul><ul><ul><li>In AUTO mode the operator can changes the controller set point in a predetermined range. </li></ul></ul><ul><ul><li>In CASCATE mode the set point is fixed. </li></ul></ul>
  39. 46. FUEL GAS HP, LP SUBSYSTEMS <ul><ul><li>EMERGENCY </li></ul></ul><ul><ul><li>If the ESD system force the SHUTDOWN of SDV-3X30 or SDV-3X31 or BDV-3X40 valves the state variable of the Fuel Gas HP-LP sub-systems that control the valves above mentioned and equipment shall be changed to UNKNOWN by means of the state RECOGNITION procedure. </li></ul></ul>
  40. 47. SEAL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Depressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZATION: Dynamic state which allows to vent process fluid. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZATION dynamic state allows the transition from any state to DEPRESSURIZED. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to DEPRESSURIZED status during the execution of DEPRESSURIZATION procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Gas compressor LP A,B – HP A,B shall not be pressurized (ST_Case_Pressurized signal shall be reset).. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Seal Gas sub system inlet valve “SDV – 3X50“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Seal Gas vent valve “BDV – 3X52“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3X53” shall be lower than set point. </li></ul></ul></ul></ul></ul>
  41. 49. SEAL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Depressurized state: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZED: Static state with inlet seal gas feed valve “SDV – 3X50“ closed (properly this state certifies a NOT-PRESSURIZED process sub-system). </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZED state can be achieved by completing the procedure of DEPRESSURIZATION. </li></ul></ul></ul></ul></ul><ul><ul><li>SAFETY CONDITION of process sub-system, that represents the final condition of automatic protection procedures, coincides with DEPRESSURIZED state. </li></ul></ul><ul><ul><li>In order to maintain the DEPRESSURIZED SUB SYSTEM status essentially the following conditions shall be verified : </li></ul></ul><ul><ul><ul><ul><ul><li>Seal Gas sub system inlet valve “SDV – 3X50“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Seal Gas vent valve “BDV – 3X52“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3X53” shall be lower than set point. </li></ul></ul></ul></ul></ul>
  42. 51. SEAL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Pressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZATION: Dynamic state which allows the purging of trapped air and the pressurization of process sub-system. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZATION dynamic state allows the transition from DEPRESSURIZED to PRESSURIZED. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to PRESSURIZED status the execution of PRESSURIZATION procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>HP Fuel Gas good conditions shall be verified. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Seal Gas sub system inlet valve “SDV – 3X50“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Seal Gas purging shall be carried out . </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Seal Gas vent valve “BDV – 3X52“ shall be closed when the purging TIMEOUT is expired. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3X53” shall be above the set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Vent_Monitoring_2 variable status shall be set. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3X53” shall be above the set point. </li></ul></ul></ul></ul></ul>
  43. 52. SEAL GAS HP, LP SUBSYSTEMS <ul><ul><li>The “VENT MONITORING” procedure is &quot;always running“ and if the conditions showed hereafter are </li></ul></ul><ul><ul><li>verified during its execution a Vent_Monitoring_2 variable reset shall be carried out to avoid a process </li></ul></ul><ul><ul><li>fluid contamination : </li></ul></ul><ul><ul><ul><ul><li>Seal Gas process sub plant pressure “PIT – 3X53“ is below the threshold. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Seal Gas sub system inlet valve “SDV – 3X50“ is open & Hp Fuel Gas Header sub system is not </li></ul></ul></ul></ul><ul><ul><ul><ul><li>purged. </li></ul></ul></ul></ul><ul><ul><li>In case the operator is operating in manual mode it shall be possible for the operator to force </li></ul></ul><ul><ul><li>VENT_MONITORING_2 STATUS by a dedicated push button which is active / inactive whether all HP </li></ul></ul><ul><ul><li>Fuel gas header sub-system vent monitoring conditions are verified. </li></ul></ul>
  44. 54. SEAL GAS HP, LP SUBSYSTEMS <ul><ul><li>The process sub-system can be in Pressurized state: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZED: Static state with seal gas inlet feed valve open and seal gas vent valve closed. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZED state can be achieved by completing the procedure of PRESSURIZATION. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the PRESSURIZED SUB SYSTEM status essentially the following conditions shall be verified : </li></ul></ul><ul><ul><ul><ul><ul><li>Seal Gas sub system inlet valve “SDV – 3X50“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Seal Gas sub system vent valve “BDV – 3X52“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3X53” shall be above the set point. </li></ul></ul></ul></ul></ul>
  45. 56. SEAL GAS HP, LP SUBSYSTEMS <ul><ul><li>EMERGENCY </li></ul></ul><ul><ul><li>If the ESD system force the SHUTDOWN of SDV-3X50 or BDV-3X52 the state variable of the Seal Gas HP-LP sub-systems that control the valves above mentioned and equipment shall be changed to UNKNOWN by means of the state RECOGNITION procedure. </li></ul></ul>
  46. 57. <ul><ul><li>The process sub-system can be in Depressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZATION: dynamic state which leads to STOP DEPRESSURIZED state. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZATION dynamic state allows the transition from any state to STOP DEPRESSURIZED. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to DEPRESSURIZED status during the execution of DEPRESSURIZATION procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Slug Catcher inlet valve “SDV-3111” shall be closed </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Loading line bypass valve “SDV-3112” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Discharge pipeline vent valve “BDV-3135” shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Station delivery line valve “SDV-3134” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3113” upstream the Slug Catcher shall be under the set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3114” & “PIT-3115” in the Inter stage Headers shall be under the set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3123” within the Filter Separator shall be under the set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3133” at the station discharge shall be under the set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The PID-3133 regulator shall be set in AUTO with a predetermined set point. </li></ul></ul></ul></ul></ul>MAIN HEADER SUBSYSTEMS
  47. 62. MAIN HEADER SUBSYSTEMS <ul><ul><li>The process sub-system can be in Pressurized state: </li></ul></ul><ul><ul><ul><ul><ul><li>STOP DEPRESSURIZED: turbine stopped with outlet valves “SDV-3134” closed, inlet valve “SDV-3111” closed, vent line “BDV-3135” valve opened. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>STOP DEPRESSURIZED state can be achieved by completing the procedure of DEPRESSURIZATION. </li></ul></ul></ul></ul></ul><ul><ul><li>The SAFETY CONDITION of process sub-system (which is the final condition of the automatic safety procedures) corresponds to the STOP DEPRESSURIZED state. </li></ul></ul><ul><ul><li>In order to maintain the STOP DEPRESSURIZED SUB SYSTEM status essentially the following conditions shall be verified: </li></ul></ul><ul><ul><ul><ul><ul><li>Loading line bypass valve “SDV-3112” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Slug Catcher inlet valve “SDV-3111” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Station delivery line valve “SDV-3134” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Discharge pipeline vent valve “BDV-3135” shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3113” upstream the Slug Catcher shall be lower than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3114” & “PIT-3115” in the Inter stage Headers shall be lower than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3123” within the Filter Separator shall be lower than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3133” at the station discharge shall be under the set point. </li></ul></ul></ul></ul></ul>
  48. 63. MAIN HEADER SUBSYSTEMS <ul><ul><li>The process sub-system can be in Pressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZATION: dynamic state which allows the purging of trapped air and the pressurization of process sub-system. It leads to STOP PRESSURIZED state. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZATION dynamic state allows the transition from STOP DEPRESSURIZED to STOP PRESSURIZED. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to STOPPED PRESSURIZED status during the execution of PRESSURIZATION procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Manual valves “VBD10-3125”, “VBD10-3127”, “VBD10-3126” on MAK-3120 filter separator Skid , “VBD10-3615” , </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>“ VBD10-3616”, “VBD10-3617” on Dehydration Skid and “VBD10-3621”, “VBD10-3142”, “VBD10-3143” shall be closed and valves on Main Header shall be open and operator shall confirm it.. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>At the beginning Loading line bypass valve “SDV-3112” shall be open & fluid pressure “PIT-3113”, </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>“ PIT-3114”, “PIT-3115”, “PIT-3123”, “PIT-3133 shall be lower than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Main Header sub system purging shall be carried out . </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Discharge pipeline vent valve “BDV–3135“ shall be closed when the purging TIMEOUT is expired. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Differential pressure “PDS-3112” across the Slug Catcher inlet valve “SDV-3111” shall be lower than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Slug Catcher inlet valve “SDV-3111” shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Loading line bypass valve “SDV-3112” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3113”, “PIT-3114”, “PIT-3115”, “PIT-3123”, “PIT-3133 shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Vent_Monitoring_4 variable status shall be set. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The PID-3133 industrial regulator shall be set in AUTO with a predetermined set point. </li></ul></ul></ul></ul></ul>
  49. 65. MAIN HEADER SUBSYSTEMS <ul><ul><ul><li>If the MAK-3120 is BY-PASSED, during the execution of PRESSURIZATION sequence, it is requested to operator the </li></ul></ul></ul><ul><ul><ul><li>confirmation of VBD10-3125 CLOSED, VBD10-3127 CLOSED, VBD10-3126 OPEN. </li></ul></ul></ul><ul><ul><ul><li>If the MAK-3120 is ON-DUTY ,during the execution of PRESSURIZATION sequence, it is requested to </li></ul></ul></ul><ul><ul><ul><li>operator the confirmation of: VBD10-3125 OPEN, VBD10-3127 OPEN, VBD10-3126 CLOSED. </li></ul></ul></ul><ul><ul><ul><li>Operator can by-pass the filter separator by insert a password into the ESD. </li></ul></ul></ul><ul><ul><ul><li>This password switch off the checking of DCS and ESD on the filter separator to avoid possible alarms. </li></ul></ul></ul><ul><ul><ul><li>The same password has to be inserted to come back, to enable again DCS and ESD checking. </li></ul></ul></ul><ul><ul><ul><li>When checking is enabled again the DCS shall leads the sub system status to unknown and SRP shall be run to recognize the plant sub-system state. </li></ul></ul></ul>
  50. 66. MAIN HEADER SUBSYSTEMS <ul><ul><li>If the Glycol Dehydration Skid is BY-PASSED, during the execution of PRESSURIZATION sequence, it is requested to </li></ul></ul><ul><ul><li>operator the confirmation of: VBD10-3616 CLOSED, VBD10-3617 CLOSED, VBD10-3615 OPEN </li></ul></ul><ul><ul><li>Operator can by-pass the Glycol Dehydration Skid by insert a password into the ESD. </li></ul></ul><ul><ul><li>This password switch off the checking of DCS and ESD on the filter separator to avoid possible alarms. </li></ul></ul><ul><ul><li>The same password has to be inserted to come back, to enable again DCS and ESD checking. </li></ul></ul><ul><ul><li>When checking is enabled again the DCS shall leads the sub system status to unknown and SRP shall be run to recognize the plant sub-system state. </li></ul></ul><ul><ul><li>However this password shall not take effect on the glycol regeneration utility system. </li></ul></ul><ul><ul><li>If the Glycol Dehydration Skid is ON-DUTY, during the execution of PRESSURIZATION sequence, it is requested to </li></ul></ul><ul><ul><li>operator the confirmation of: VBD10-3616 OPEN, VBD10-3617 OPEN, VBD10-3615 CLOSED </li></ul></ul>
  51. 67. MAIN HEADER SUBSYSTEMS <ul><ul><ul><li>A dedicated procedure &quot;always running“ manages the drainage operations of the discharge filter separator and the slug catcher. </li></ul></ul></ul><ul><ul><ul><li>These procedures maintain the liquid between two defined level by operating the discharge filter separator control valves LV-3121A and LV-3122A and the slug catcher control valves LV-3114A. </li></ul></ul></ul><ul><ul><ul><li>Hysteresis is necessary to avoid continuous changeover. </li></ul></ul></ul><ul><ul><ul><li>A PID industrial controls the valve PV-3133 which regulates the pressure at the station discharge. </li></ul></ul></ul>
  52. 68. MAIN HEADER SUBSYSTEMS <ul><ul><li>The “VENT MONITORING” procedure is &quot;always running“ and if the following conditions are verified during its execution a Vent_Monitoring _4 variable reset shall be carried out to avoid a process fluid contamination : </li></ul></ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3113” upstream the Slug Catcher is lower than set point. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3114” or “PIT-3115” in the Inter stage Headers is lower than set point. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3123” within the Filter Separator is lower than set point. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3133” at the station discharge is lower than set point. </li></ul></ul></ul></ul><ul><ul><li>In case the operator is operating in manual mode it shall be possible for the operator to force VENT_MONITORING_4 STATUS by a dedicated push button which is active / inactive whether all HP Fuel gas header sub-system vent monitoring conditions are verified. </li></ul></ul>
  53. 70. MAIN HEADER SUBSYSTEMS <ul><ul><li>The process sub-system can be in Stop Pressurized state: </li></ul></ul><ul><ul><ul><ul><ul><li>STOP PRESSURIZED: turbine stopped, outlet valves “SDV-3134” closed, inlet valve “SDV-3111” opened, </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>vent line “BDV-3135” valve closed. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>STOP PRESSURIZED state can be achieved by completing the procedures of STOPPING and </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZATION. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the STOP PRESSURIZED SUB SYSTEM status essentially the following conditions shall be verified : </li></ul></ul><ul><ul><ul><ul><ul><li>Loading line bypass valve “SDV-3112” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Slug Catcher inlet valve “SDV-3111” shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Station delivery line valve “SDV-3134” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Discharge pipeline vent valve “BDV-3135” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3113” upstream the Slug Catcher shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3114” & “PIT-3115” in the Inter stage Headers shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3123” within the Filter Separator shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3133” at the station discharge shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Vent_Monitoring_4 variable status shall be set. </li></ul></ul></ul></ul></ul>
  54. 75. MAIN HEADER SUBSYSTEMS <ul><ul><li>The process sub-system can be in Starting state: </li></ul></ul><ul><ul><ul><ul><ul><li>STARTING: dynamic state whom leads to RUN state. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>STARTING dynamic state allows the transition from STOP PRESSURIZED to RUN. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to RUN status during the execution of STARTING procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Differential pressure across the station delivery line valve “SDV-3134” shall be lower than set point.. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Station delivery line valve “SDV-3134” shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3113” upstream the Slug Catcher shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3114” & “PIT-3115” in the Inter stage Headers shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3123” within the Filter Separator shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3133” at the station discharge shall be higher than set point. </li></ul></ul></ul></ul></ul>
  55. 76. MAIN HEADER SUBSYSTEMS <ul><ul><li>The process sub-system can be in RUN state: </li></ul></ul><ul><ul><ul><ul><ul><li>RUN: operating functioning (compressors running and on load). </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>RUN state can be achieved by completing the procedure of STARTING. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the RUN SUB SYSTEM status essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Loading line bypass valve “SDV-3112” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Slug Catcher inlet valve “SDV-3111” shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Station delivery line valve “SDV-3134” shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Discharge pipeline vent valve “BDV-3135” shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The fluid pressure “PIT-3113” upstream the Slug Catcher shall be above the set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Vent_Monitoring_4 variable status shall be set. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>At least one compressor shall be in ON LOAD status. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>TRIGGER_x variable status shall be set if one compressor is operating in ON LOAD status. </li></ul></ul></ul></ul></ul>
  56. 77. MAIN HEADER SUBSYSTEMS <ul><ul><li>The timer T141 is the maximum time that the main header system can operate in RUN status ( with </li></ul></ul><ul><ul><li>station discharge valve opened ) without ON-LOAD turbines. If the timer T141 expires the main header </li></ul></ul><ul><ul><li>status is forced to STOPPING immediately. </li></ul></ul><ul><ul><li>The flag named TRIGGER_y is set when the first turbine reach the On-load status; from this time, the timer has no </li></ul></ul><ul><ul><li>effect, and if again no turbines is ON-LOAD, the main header status is forced to STOPPING immediately. </li></ul></ul><ul><ul><li>The flag TRIGGER_x shall be reset automatically if the state is not RUN or UNKNOWN. </li></ul></ul><ul><ul><li>This function is used to avoid the backflow of gas from the pipeline to the compression station through the check </li></ul></ul><ul><ul><li>valve. </li></ul></ul><ul><ul><li>To avoid the risk to close the station discharge valve “ SDV - 3134 “ while a turbine is ON-LOAD, if a turbine </li></ul></ul><ul><ul><li>state is not defined (serial link in bad status) the trigger function is disabled. </li></ul></ul>
  57. 78. MAIN HEADER SUBSYSTEMS <ul><ul><li>The process sub-system can be in STOPPING state: </li></ul></ul><ul><ul><ul><ul><ul><li>STOPPING: dynamic state whom leads to STOP PRESSURIZED state. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>STOPPING dynamic state allows the transition from RUN to STOP PRESSURIZED. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to STOPPED PRESSURIZED status during the execution of STOPPING procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Station delivery line valve “SDV-3134” shall be open. </li></ul></ul></ul></ul></ul>
  58. 81. <ul><ul><li>EMERGENCY </li></ul></ul><ul><ul><li>If the ESD system force the SHUTDOWN of SDV-3111 or SDV-3112 or SDV-3134 or BDV-3135 the state variable of the Main Header sub-system that control the valves above mentioned and equipment shall be changed to UNKNOWN by means of the state RECOGNITION procedure . </li></ul></ul>MAIN HEADER SUBSYSTEMS
  59. 82. GLYCOL UTILITY SUBSYSTEMS <ul><ul><li>The process sub-system can be in Depressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZATION: Dynamic state with delivery valve “ SDV – 3138 ” closed. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZATION dynamic state allows the transition from any state to </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZED. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to DEPRESSURIZED status during the execution of </li></ul></ul><ul><ul><li>DEPRESSURIZATION procedure essentially the following conditions and actions shall be verified and </li></ul></ul><ul><ul><li>followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Glycol regeneration utility sub system inlet valve “SDV – 3138“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3138” shall be lower than set point. </li></ul></ul></ul></ul></ul>
  60. 85. GLYCOL UTILITY SUBSYSTEMS <ul><ul><li>The process sub-system can be in Pressurized state: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZED: Static state with delivery valve “ SDV – 3138 “ closed (properly this state certifies a NOT-PRESSURIZED process sub-system). </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>DEPRESSURIZED state can be achieved by completing the procedure of DEPRESSURIZATION. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the DEPRESSURIZED SUB SYSTEM status essentially the following conditions shall be verified : </li></ul></ul><ul><ul><ul><ul><ul><li>Glycol regeneration utility sub system inlet valve “SDV – 3138“ shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3138” shall be lower than set point. </li></ul></ul></ul></ul></ul>
  61. 87. GLYCOL UTILITY SUBSYSTEMS <ul><ul><li>The process sub-system can be in Depressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZATION: Dynamic state with delivery valve “ SDV – 3138 “ opened. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZATION: Dynamic state which allows the transitions from DEPRESSURIZED to </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZED. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to PRESSURIZED status during the execution of PRESSURIZATION </li></ul></ul><ul><ul><li>procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>Pipeline pressure “PIT-3134” shall be above the set point.. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Glycol regeneration utility sub system inlet valve “SDV – 3138“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3138” shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Purging TIMEOUT shall be expired. </li></ul></ul></ul></ul></ul>
  62. 89. GLYCOL UTILITY SUBSYSTEMS <ul><ul><li>The process sub-system can be in Pressurized state: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZED: Static state with delivery valve “ SDV – 3138 “ open. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>PRESSURIZED state can be achieved by completing the procedure of PRESSURIZATION. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the PRESSURIZED SUB SYSTEM status essentially the following conditions shall be verified : </li></ul></ul><ul><ul><ul><ul><ul><li>Glycol regeneration utility sub system inlet valve “SDV – 3138“ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Process sub plant pressure “PIT-3138” shall be higher than set point. </li></ul></ul></ul></ul></ul>
  63. 92. GLYCOL UTILITY SUBSYSTEMS <ul><ul><li>Operator can by-pass the gas dehydration system by operating the manual valves VBD10-3615, 3616, 3617. </li></ul></ul><ul><ul><li>In this case the operator must insert a password into the ESD system. </li></ul></ul><ul><ul><li>However this password shall not take effect on the glycol regeneration utility system. </li></ul></ul>
  64. 93. <ul><ul><li>EMERGENCY </li></ul></ul><ul><ul><li>If the ESD system force the SHUTDOWN of SDV-3138 the state variable of the Glycol Utility sub-system that control the valve above mentioned and equipment shall be changed to UNKNOWN by means of the state RECOGNITION procedure . </li></ul></ul>GLYCOL UTILITY SUBSYSTEMS
  65. 94. GLYCOL UTILITY SYSTEM <ul><ul><li>Gas forwarded though line 1”-A10-080-FG-12114 to the regeneration skid is used for two services: </li></ul></ul><ul><ul><ul><li>as stripping gas for regeneration purpose; </li></ul></ul></ul><ul><ul><ul><li>as blanketing  in order to preserve glycol from atmosphere contamination. </li></ul></ul></ul><ul><ul><li>When the gas flow is 0, the stripping gas is not necessary, but the gas for blanketing is still necessary. </li></ul></ul><ul><ul><li>For this reason is considered not correct to close the SDV-3138 when the station flow is 0 and the gas out of our battery limit is cold. </li></ul></ul><ul><ul><li>In order to avoid that cold gas at high pressure is forwarded to regeneration skid, generating problem on PCV 3134/3135 it is better to adopt the following procedure: </li></ul></ul><ul><ul><ul><li>Close 1” valves  3826 and 3828 (SEE P&ID 7035-PH-0410). These valves are on the stripping gas line, if these valves are closed the gas flow through SDV-3138 and PCV-3134/3135 is very low. </li></ul></ul></ul><ul><ul><ul><li>Depressurize the part of pipe between discharge station valve SDV-3134 and SOCAR’s manual valve at 20 bar. </li></ul></ul></ul><ul><ul><li>In this way the Differential Pressure across PCV3134/3135 is low and the possibility to damage the PCV is reduced. </li></ul></ul>
  66. 97. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>The process sub-system can be in Cold Catch state: </li></ul></ul><ul><ul><ul><ul><ul><li>COLD CATCH: Dynamic state after START command and STAND BY command disable. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>COLD CATCH allows the transition from RUNNING state to READY state. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to READY status during the execution of COLD CATCH procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>DCS shall disables START command “XS-3610A” and Stand by command “XS-3610B” to PLC Glycol Control System. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends REMOTE signal “UL-3610D” to DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends “READY TO START” signal “UL-3610A” to DCS before TIMEOUT will expire. </li></ul></ul></ul></ul></ul>
  67. 98. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>The process sub-system can be in Ready state: </li></ul></ul><ul><ul><ul><ul><ul><li>READY: Static state result of the fact that PLC whom controls the skid is ready to start. (Default state). </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>READY state is reachable after COLD CATCH procedure (or like default status). </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the READY SUB SYSTEM status essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends REMOTE signal “UL-3610D” to DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends “READY TO START” signal “UL-3610A” to DCS. </li></ul></ul></ul></ul></ul>
  68. 99. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>PLC Glycol system sends the “ READY TO START ” signal </li></ul></ul><ul><ul><li>“ UL-3610A” to DCS when the following conditions are verified: </li></ul></ul><ul><ul><ul><li>When SDV 3613B, SDV 3614B, SDV 3707 close PLC </li></ul></ul></ul><ul><ul><ul><li>command is active, close limit switch feedback </li></ul></ul></ul><ul><ul><ul><li>signal shall be reached in a predetermined time. </li></ul></ul></ul><ul><ul><ul><li>Emergency shut down from PLC shall not be active. </li></ul></ul></ul><ul><ul><ul><li>Shut down from ESD system “XSD-3610” shall not be </li></ul></ul></ul><ul><ul><ul><li>active. </li></ul></ul></ul><ul><ul><ul><li>The instrument air pressure “PSL 3713” shall be inside a </li></ul></ul></ul><ul><ul><ul><li>predetermined range. </li></ul></ul></ul><ul><ul><ul><li>The contactor glycol level “LSHH-3614B” shall be inside a </li></ul></ul></ul><ul><ul><ul><li>predetermined range. </li></ul></ul></ul><ul><ul><ul><li>If one of the conditions above mentioned is not verified </li></ul></ul></ul><ul><ul><ul><li>a “ Glycol Dehydration Package Trip shall occurred”. </li></ul></ul></ul><ul><ul><ul><li>The contactor glycol level “LSLL-3613B” shall be </li></ul></ul></ul><ul><ul><ul><li>inside a predetermined range. </li></ul></ul></ul><ul><ul><ul><li>The pressure outlet pump “PAHH-3714” shall be inside a </li></ul></ul></ul><ul><ul><ul><li>predetermined range. </li></ul></ul></ul><ul><ul><ul><li>The Glycol Flush Drum pressure “PT 3717” & level </li></ul></ul></ul><ul><ul><ul><li>“ LAH 3705” & “LAH 3709” shall be inside a </li></ul></ul></ul><ul><ul><ul><li>predetermined range. </li></ul></ul></ul><ul><ul><ul><li>The glycol accumulator level “LALL 3713” shall be inside a </li></ul></ul></ul><ul><ul><ul><li>predetermined range. </li></ul></ul></ul><ul><ul><ul><li>When PLC Glycol control system sends start </li></ul></ul></ul><ul><ul><ul><li>“ OBB-3710A/B” pump command to MCC the “OBB-3710A” </li></ul></ul></ul><ul><ul><ul><li>glycol pump running feedback signal shall be reached by </li></ul></ul></ul><ul><ul><ul><li>PLC Glycol Control system in a predetermined time. </li></ul></ul></ul><ul><ul><ul><li>“ Alarm Glycol Pump “OBB-3710A” or OBB-3710B not </li></ul></ul></ul><ul><ul><ul><li>occurred”. </li></ul></ul></ul><ul><ul><ul><li>When PLC Glycol control system sends start command to </li></ul></ul></ul><ul><ul><ul><li>MCC the ELECTRICAL HEATER running feedback signal </li></ul></ul></ul><ul><ul><ul><li>shall be reached in a predetermined time. </li></ul></ul></ul><ul><ul><ul><li>“ Alarm Electrical Heater not occurred”. </li></ul></ul></ul><ul><ul><ul><li>PLC shall not receives the ELECTRICAL HEATER NOT </li></ul></ul></ul><ul><ul><ul><li>READY signal from Electrical Heater. </li></ul></ul></ul><ul><ul><ul><li>(LSLL-3712; TSHH-3716; .. SEE FIGURE) </li></ul></ul></ul>
  69. 106. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>The process sub-system can be in Depressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>PREHEATING: Dynamic state after STAND BY command. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>PREHEATING allows the transition from READY state to HOT state. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to HOT status during the execution of PREHEATING procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends REMOTE signal “UL-3610D” to DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If Glycol regeneration utility sub system inlet pressure “PIT-3138” is not higher than a predetermined set point a calling to “Cold Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If Contactor outlet pressure “PIT-3133” is not higher than a predetermined set point a calling to “Cold Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>DCS shall sends “STAND BY” command “XS-3610B” to PLC Glycol Control System. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends “HOT STATUS” signal “UL-3610B” to DCS . </li></ul></ul></ul></ul></ul>
  70. 107. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>PLC Glycol system switch on the Electrical Heater when the following conditions are verified: </li></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall receives the STAND BY command “XS-3610B” from DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Electrical Heater shall sends Remote signal to PLC Glycol Control System. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>“ Alarm Electrical Heater shall not occurred”. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>“ Glycol Dehydration Package Trip shall not occurred”. </li></ul></ul></ul></ul></ul>
  71. 109. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>The process sub-system can be in HOT state: </li></ul></ul><ul><ul><ul><ul><ul><li>HOT: Static state result of the fact that PLC whom controls the skid has completed the preheating procedure. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>HOT state is reachable after HOT CATCH from RUNNING state or after PREHEATING procedure from READY. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the HOT SUB SYSTEM status essentially the following conditions and actions shall be verified and followed through : </li></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends REMOTE signal “UL-3610D” to DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If Glycol regeneration utility sub system inlet pressure “PIT-3138” is not higher than a predetermined </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>set point a calling to “Cold Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If Contactor outlet pressure “PIT-3133” is higher than a predetermined set point a calling to “Cold </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends “HOT STATUS” signal to DCS. </li></ul></ul></ul></ul></ul>
  72. 110. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>PLC Glycol system sends to DCS the HOT signal when the following conditions are verified: </li></ul></ul><ul><ul><ul><ul><ul><li>LIC 3613A & LIC 3706 level controller AUTO operating mode shall be set. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The pressure outlet pump “PAHH 3714” shall be inside a predetermined range. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The Glycol Flush Drum pressure “PT 3717” & level “LAH 3705” shall be inside a predetermined range. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The glycol accumulator level “LALL 3713” shall be inside a predetermined range. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>“ Alarm Glycol Pump “OBB-3710A” or “OBB-3710B” shall not occurred”. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>“ Glycol Dehydration Package Trip shall not occurred”. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PLC shall receives the STAND BY command “XS-3610B” from DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The Glycol Reboiler temperature “TT 3712” shall be inside a predetermined range. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The contactor glycol level “LSHH 3613B” shall be inside a predetermined range. </li></ul></ul></ul></ul></ul>
  73. 111. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>The process sub-system can be in Depressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>STARTING: Dynamic state after START command. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>STARTING allows the transition from HOT state to RUNNING state. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to RUNNING status during the execution of STARTING procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends REMOTE signal “UL-3610D” to DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If Glycol regeneration utility sub system inlet pressure “PIT-3138” is not higher than a predetermined set point a calling to “Cold Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If Contactor outlet pressure “PIT-3133” is not higher than a predetermined set point a a calling to “Cold Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Flow rate “FIT-3132” on Main Header System shall be available.. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>DCS shall sends the START command “XS-3610A” to PLC Glycol Control System. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends “RUNNING” signal “UL-3610E” to DCS. </li></ul></ul></ul></ul></ul>
  74. 112. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>PLC Glycol Control System switch on the OBB-3710A or OBB-3710B glycol pump when the following conditions are </li></ul></ul><ul><ul><li>verified: </li></ul></ul><ul><ul><ul><ul><ul><li>PLC shall receives the START command “XS-3610A” from DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The Glycol pump “OBB-3710A” or “OBB-3710B” shall be selected. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The pressure outlet pump “PAHH 3714” shall be inside a predetermined range. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The Glycol accumulator level “LALL 3713” shall be inside a predetermined range. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The Glycol Reboiler temperature TT 3712” shall be inside a predetermined range. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The contactor Glycol level “LSHH 3613B” shall be inside a predetermined range. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>“ Alarm Glycol Pump “OBB-3710A” or “OBB-3710B” shall not occurred”. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>“ Glycol Dehydration Package Trip shall not occurred”. </li></ul></ul></ul></ul></ul>
  75. 114. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>The process sub-system can be in Running state: </li></ul></ul><ul><ul><ul><ul><ul><li>RUNNING: Static state result of the fact that PLC whom controls the skid is in running mode. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>RUNNING state is reachable after STARTING procedure from HOT state. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the RUNNING SUB SYSTEM status essentially the following conditions shall be verified : </li></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends REMOTE signal “UL-3610D” to DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If Glycol regeneration utility sub system inlet pressure “PIT-3138” is not higher than a predetermined set point a calling to “Cold Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If Contactor outlet pressure “PIT-3133” is not higher than a predetermined set point a calling to “Cold Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If a flow rate “FIT-3132” is not available on Main Header System a calling to “Hot Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends “RUNNING” signal “UL-3610E” to DCS. </li></ul></ul></ul></ul></ul>
  76. 115. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>PLC Glycol system sends RUNNING signal “UL-3610A“ to DCS when the following conditions are verified: </li></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall receives the START command “XS-3610A“ from DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>At least one Glycol Pump “OBB-3710A” or “OBB-3710B” shall be running. </li></ul></ul></ul></ul></ul>
  77. 116. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>The process sub-system can be in Depressurization state: </li></ul></ul><ul><ul><ul><ul><ul><li>HOT CATCH: Dynamic state after START command disable (STOP). </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>HOT CATCH allows the transition from RUNNING state to HOT state. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to HOT status during the execution of HOT CATH procedure essentially the following conditions and actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>DCS shall disables START command “XS-3610A” to PLC Glycol Control System. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PLC Glycol Control System shall sends REMOTE signal “UL-3610D” to DCS. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If Glycol regeneration utility sub system inlet pressure “PIT-3138” is not higher than a </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>predetermined set point a calling to “Cold Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>If Contactor outlet pressure “PIT-3133” is not higher than a predetermined set point a calling to “Cold Catch” procedure shall be carried out. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Glycol Control System shall sends “HOT STATUS” signal “UL-3610B” to DCS. </li></ul></ul></ul></ul></ul>
  78. 118. GLYCOL REGENERATION SUBSYSTEMS <ul><ul><li>EMERGENCY </li></ul></ul><ul><ul><ul><ul><li>When Glycol regeneration skid shutdown XSD-3610 signal is forced the state variable of the Glycol Reg. sub-system shall be changed to UNKNOWN by means of the state RECOGNITION procedure. </li></ul></ul></ul></ul>
  79. 119. GLYCOL SYSTEM CONTROLLERS <ul><ul><li>PLC Glycol control system enables the Temperature controller “TIC-3712” set point of 0 C when at least one of the </li></ul></ul><ul><ul><li>following conditions is verified: </li></ul></ul><ul><ul><ul><ul><li>Heater Control Panel shall not send REMOTE signal “UL-3710C” to PLC Glycol Control System. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>DCS shall not sends START command “XS-3610A” to PLC Glycol Control System & PLC Glycol Control System </li></ul></ul></ul></ul><ul><ul><ul><ul><li>shall not sends START command to Heater Control Panel. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Shut down from ESD system shall not be active. </li></ul></ul></ul></ul><ul><ul><li>PLC Glycol control system enables the Temperature controller “TIC-3712” set point of 80 C when the following </li></ul></ul><ul><ul><li>conditions are verified: </li></ul></ul><ul><ul><ul><ul><li>DCS shall not sends START command “XS-3610A” to PLC Glycol Control System & PLC Glycol Control System </li></ul></ul></ul></ul><ul><ul><ul><ul><li>shall sends START command to Heater Control Panel. </li></ul></ul></ul></ul><ul><ul><li>PLC Glycol control system enables the Temperature controller “TIC-3712” set point of 200 C when the following </li></ul></ul><ul><ul><li>conditions are verified: </li></ul></ul><ul><ul><ul><ul><li>DCS shall sends START command “XS-3610A” to PLC Glycol Control System & PLC Glycol Control System </li></ul></ul></ul></ul><ul><ul><ul><ul><li>shall sends START command to Heater Control Panel. </li></ul></ul></ul></ul>
  80. 120. GLYCOL SYSTEM CONTROLLERS <ul><ul><li>Temperature controller “TIC-3710” AUTO operating mode is enabled when the following conditions are verified: </li></ul></ul><ul><ul><ul><ul><li>DCS shall sends START command “XS-3610A” to PLC Glycol Control System. </li></ul></ul></ul></ul>
  81. 121. GLYCOL SYSTEM CONTROLLERS <ul><ul><ul><li>Level controller “LIC 3706” AUTO operating mode is enabled when the following conditions are verified: </li></ul></ul></ul><ul><ul><ul><ul><ul><li>DCS shall sends STAND BY command “XS-3610B” to PLC Glycol Control System. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The contactor glycol level “LALL 3708” shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The Glycol Flush Drum pressure “PT 3717” shall be higher than set point. </li></ul></ul></ul></ul></ul>
  82. 122. GLYCOL SYSTEM CONTROLLERS <ul><ul><li>Flow controller “FIC 3700” AUTO operating mode is enabled when the following conditions are verified : </li></ul></ul><ul><ul><ul><ul><ul><li>DCS shall sends START command “XS-3610A” to PLC Glycol Control System. </li></ul></ul></ul></ul></ul><ul><ul><li>If the pump “OBB-3710A” is running, the changeover to pump “OBB-3710B” is performed when the following conditions are verified: </li></ul></ul><ul><ul><ul><ul><ul><li>The pump “OBB-3710A” shall be selected. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>“ Alarm Glycol Pump “OBB-3710A” shall occurred”. </li></ul></ul></ul></ul></ul>
  83. 123. GLYCOL SYSTEM CONTROLLERS <ul><ul><ul><li>Level controller “LIC 3613A” AUTO operating mode is enabled when the following conditions are verified: </li></ul></ul></ul><ul><ul><ul><ul><ul><li>DCS shall sends STAND BY command “XS-3610B” to PLC Glycol Control System. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The contactor glycol level “LSLL 3613B” shall be higher than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The Glycol Flush Drum level “LAH 3709” shall be lower than set point. </li></ul></ul></ul></ul></ul>
  84. 124. TURBINE LP A,B – HP A,B SUBSYSTEMS <ul><ul><li>The process sub-system can be in STOPPING state: </li></ul></ul><ul><ul><ul><ul><li>STOPPING Dynamic state which leads to READY state. </li></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><li>STOPPING is a dynamic state that allows the transition from any state to READY state. </li></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to READY during the execution of STOPPING procedure essentially the following conditions & actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><li>DCS shall forces the STOP command “ XS – 3X44 ” to UCP turbine control system. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Turbine Cool down shall be initiated and UCP control system shall sends the Cool down signal to DCS. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Turbine speed shall be lower than set point. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>DCS shall removes STOP command to UCP control system and cooler stopping timer shall be started up. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>N cooler motors shall not be fault. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>UCP turbine control system shall sends the “ READY TO RUN “ signal to DCS. </li></ul></ul></ul></ul><ul><ul><li>STOPPING </li></ul></ul><ul><ul><li>TRUE </li></ul></ul>
  85. 125. TURBINE LP A,B – HP A,B SUBSYSTEMS <ul><ul><li>The process sub-system can be in Ready state: </li></ul></ul><ul><ul><ul><ul><ul><li>READY: Static state with turbine stopped and ready to start. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>READY state is reachable after STOPPING procedure. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the READY SUB-SYSTEM status essentially the following conditions shall be verified & actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>At least N cooler motors shall not be fault </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Turbine actual speed shall be lower than set point. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>UCP turbine control system shall sends the “ READY TO RUN “ signal to DCS. </li></ul></ul></ul></ul></ul>
  86. 126. TURBINE LP A,B – HP A,B SUBSYSTEMS <ul><ul><li>The process sub-system can be in STARTING state: </li></ul></ul><ul><ul><ul><ul><li>STARTING: Dynamic state which leads to IDLE state from READY state. </li></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><li>STARTING is a dynamic state that allows the transition from READY state to IDLE state. </li></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to IDLE during the execution of STARTING procedure essentially the following conditions & actions shall be verified and followed through; </li></ul></ul><ul><ul><ul><ul><li>The variable HAW_START status shall be checked and updates to ON status if it is in OFF status. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Cooler motors starting shall be carried out sequentially and at the end of this phase the variable HAW_START shall be reset to off status. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>HP Turbines: Main Header HP suction pressure shall be higher than set point. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>DCS shall selects NGP control (Manual) and sends remote speed set point to UCP turbine control system. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>DCS shall sends START command “ XS – 3X40 “ to UCP turbines control system. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>UCP turbine control system shall sends the “ READY TO LOAD “ signal to DCS. </li></ul></ul></ul></ul><ul><ul><li>STARTING </li></ul></ul>
  87. 127. <ul><ul><ul><ul><li>The turbine control from DCS is possible only if the serial link connection working rightly. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>The turbine commands from DCS to the turbine are enabled only if the turbine CONTROL MODE from UCP is in REMOTE. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>In this case, if the sub-system is in SEMI-AUTOMATIC, the turbine status is controlled by using the NGP or suction pressure </li></ul></ul></ul></ul><ul><ul><ul><ul><li>set point control mode. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>To pilot the Turbine in IDLE state, the control is set to MANUAL (NGP) with a set-point of 80%, while to pilot the LP Turbine </li></ul></ul></ul></ul><ul><ul><ul><ul><li>in ON-Load state the control is set to AUTO (suction pressure) with a set-point of 445 kPa ( 1600 Kpa for HP Unit ). </li></ul></ul></ul></ul><ul><ul><ul><ul><li>For this reason, in SEMI-AUTOMATIC mode, the set-point are locked and the operator can not change it. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>If the sub-system is in MANUAL, the turbine state can be change by operator from DCS changing the NGP or PRESSURE </li></ul></ul></ul></ul><ul><ul><ul><ul><li>set point values. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>If the CONTROL MODE from UCP is in LOCAL or AUX no command are possible to the operator from DCS with the exception </li></ul></ul></ul></ul><ul><ul><ul><ul><li>of the STOP. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Whichever control mode is used, the automatic state recognize procedure is active to identify the turbine status. </li></ul></ul></ul></ul>TURBINE LP A,B – HP A,B SUBSYSTEMS
  88. 128. TURBINE LP A,B – HP A,B SUBSYSTEMS <ul><ul><li>To avoid an overload on the electrical system caused by inrush current, the motors of each cooler are started at </li></ul></ul><ul><ul><li>different time sequentially. </li></ul></ul><ul><ul><li>Furthermore, the variable HAW_START is used to postpone the coolers motors starting, if another cooler is in the starting phase. </li></ul></ul><ul><ul><li>If the starting phase is interrupted in asynchronous mode the variable shall be reset. </li></ul></ul><ul><ul><li>The variable HAW_START is a common parameter for all the turbine logic sequence. </li></ul></ul><ul><ul><li>The coolers motor could be started/stopped manually by the operator also if the sub-system is in Semi-auto mode. </li></ul></ul><ul><ul><li>The cooler motors status is maintained when the operation mode is switched from Semi-auto to manual and vice-versa. </li></ul></ul><ul><ul><li>The automatic cooler starting sequence is executed: </li></ul></ul><ul><ul><ul><ul><li>When the operation mode is semi-automatic and the automatic state recognize procedure, identify a new state that require gas cooling (on-load or idle states) and sub system goes from UNLNOWN state to STAND-BY or </li></ul></ul></ul></ul><ul><ul><ul><ul><li>ON LOAD state by executing the Cooler procedure. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>During STARTING dynamic phase; </li></ul></ul></ul></ul><ul><ul><ul><ul><li>During PWR-OFF phase at power recovery. </li></ul></ul></ul></ul>
  89. 129. TURBINE LP A,B – HP A,B SUBSYSTEMS <ul><ul><li>When all cooler motors are switched off the “TIC-3X33” controller AUTO or CASCATE operating mode shall be disabled and the TIC controller MANUAL operating mode shall be enable. </li></ul></ul><ul><ul><li>In Manual MODE the operator can change the controller output. </li></ul></ul><ul><ul><li>In AUTO mode the operator can changes the controller set point in a predetermined range. </li></ul></ul><ul><ul><li>In CASCATE operating mode the set point is fixed. </li></ul></ul>
  90. 130. TURBINE LP A,B – HP A,B SUBSYSTEMS <ul><ul><li>The process sub-system can be in IDLE state: </li></ul></ul><ul><ul><ul><ul><ul><li>IDLE: The unit is operating at idle set point speed (typical: 50-60% NPT or 72-78% NGP). </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>IDLE state is reachable after STARTING procedure from READY state or after UNLOADING </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>procedure from ON-LOAD state. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>IDLE state is also reachable after an electrical fault with PWR-OFF procedure. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the IDLE SUB-SYSTEM status essentially the following conditions shall be verified & actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>The minimum of N cooler motors shall be running. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>UCP turbine control system shall sends the “ READY TO LOAD “ signal to DCS. </li></ul></ul></ul></ul></ul>
  91. 131. TURBINE LP A,B – HP A,B SUBSYSTEMS <ul><ul><li>The process sub-system can be in LOADING state: </li></ul></ul><ul><ul><ul><ul><li>LOADING: Dynamic state which leads to ON-LOAD state. </li></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><li>LOADING is a dynamic state that allows the transition from IDLE state to ON-LOAD state. </li></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to ON LOAD during the execution of LOADING procedure essentially the following conditions & actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><li>UCP turbine control system shall sends CONTROL REMOTE signal to DCS. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Station discharge valve SDV 3134 shall be open.. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>HP Turbines: At least one LP turbine shall be in ON LOAD status.. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>DCS shall selects suction pressure control (AUTO) and sends to UCP turbine control system suction pressure set point command. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>UCP turbine control system shall sends the “ ON LOAD “ signal to DCS. </li></ul></ul></ul></ul><ul><ul><li>LOADING </li></ul></ul>
  92. 132. TURBINE LP A,B – HP A,B SUBSYSTEMS <ul><ul><li>The process sub-system can be in ON-LOAD state: </li></ul></ul><ul><ul><ul><ul><ul><li>ON-LOAD: The unit is operating at suction pressure set point. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>ON-LOAD state is reachable after LOADING procedure from IDLE state. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to maintain the IDLE SUB-SYSTEM status essentially the following conditions shall be verified & actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><ul><li>The minimum of N cooler motors shall be running. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>HP Turbines: At least one LP turbine shall be in ON LOAD status. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>UCP turbine control system shall sends the “ ON LOAD “ signal to DCS. </li></ul></ul></ul></ul></ul>
  93. 133. TURBINE LP A,B – HP A,B SUBSYSTEMS <ul><ul><li>The process sub-system can be in UNLOADING state: </li></ul></ul><ul><ul><ul><ul><ul><li>UNLOADING: Dynamic state which leads to IDLE state from ON-LOAD state. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>UNLOADING is a dynamic state that allows the transition from ON-LOAD state to IDLE state. </li></ul></ul></ul></ul></ul><ul><ul><li>In order to update the SUB SYSTEM status to IDLE during the execution of UNLOADING procedure </li></ul></ul><ul><ul><li>essentially the following conditions & actions shall be verified and followed through; </li></ul></ul><ul><ul><ul><ul><ul><li>DCS shall selects NGP control (MANUAL) and it shall sends remote speed set point to UCP turbine control system. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>UCP turbine control system shall sends the “ READY TO LOAD “ signal to DCS. </li></ul></ul></ul></ul></ul><ul><ul><li>UNLOADING </li></ul></ul>
  94. 134. TURBINE LP A,B – HP A,B SUBSYSTEMS <ul><ul><li>The process sub-system can be in Power Off state: </li></ul></ul><ul><ul><ul><ul><ul><li>PWR-OFF: Dynamic state that, if the turbine was running, leads to IDLE state in case of electrical fault. </li></ul></ul></ul></ul></ul><ul><ul><li>Following are showed the possible transitions: </li></ul></ul><ul><ul><ul><ul><ul><li>PWR-OFF is a dynamic state that allows the transition from any state to static state IDLE or READY </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>state by calling the STOPPING procedure. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>This transition is called automatically when a power failure is detected and shall not available in manual </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>mode. </li></ul></ul></ul></ul></ul><ul><ul><li>During the execution of PWR-OFF procedure essentially the following conditions & actions shall be verified and followed through: </li></ul></ul><ul><ul><ul><ul><li>DCS shall performs the Cooler motors stopping sequentially by forcing the variable HAW_START to the off state </li></ul></ul></ul></ul><ul><ul><ul><ul><li>and shall forces STOP command “XS – 3244” to UCP turbine Control system. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>DCS shall selects NGP control (MANUAL) and it shall sends remote speed set point to UCP turbine control system. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>When electrical power supply change back normal if Compressor speed is lower than set point, serial link status is good and Stopping Cooler timer is expired the stopping procedure is called and started up otherwise the following </li></ul></ul></ul></ul><ul><ul><ul><ul><li>conditions & actions shall be verified and followed through: </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>DCS shall performs the Cooler motors starting sequentially by forcing the variable HAW_START to ON state. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>The minimum of “N” cooler motors shall be running. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>DCS shall removes Stop command to PLC and reset from UCP shall be achieved. </li></ul></ul></ul></ul></ul><ul><ul><li>POWER OFF </li></ul></ul>
  95. 135. <ul><ul><ul><li>The COOLDOWN FORCING operation is an always run procedure which is active even if the system is in manual mode and guarantees the </li></ul></ul></ul><ul><ul><ul><li>safety operation of compressor by the checking of vital process parameters of the system. </li></ul></ul></ul><ul><ul><ul><li>The normal stop forcing is removed only when the cause is disappeared. </li></ul></ul></ul><ul><ul><ul><li>A local CD_X variable is used to force the Stop command “XS – 3X44” to the OFF state and to release it at the end of the alarm. </li></ul></ul></ul><ul><ul><ul><li>During the execution of COOLDOWN FORCING procedure if one of the following conditions are not verified the stopping procedure is </li></ul></ul></ul><ul><ul><ul><li>called and started up, </li></ul></ul></ul><ul><ul><ul><li>DCS shall forces STOP command “ XS – 3X44 ” to PLC , sets the local CD_X variable to the OFF state and </li></ul></ul></ul><ul><ul><ul><li>the Cool down of the unit shall initiate. </li></ul></ul></ul><ul><ul><ul><ul><ul><li>Main Header vent valve BDV - 3135 shall be closed. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Main Header subsystem shall be purged. (Vent_Monitoring_4 <> 0). </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Seal Gas Pressure PIT – 3X53 shall be higher than a predetermined setpoint. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Delta pressure across the inlet turbine valve “ SDV – 3X14 “ shall be below the max pressure value allowable. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Main Header station discharge valve “ SDV -3134 “ shall be open. </li></ul></ul></ul></ul></ul><ul><ul><ul><li>If the condition above mentioned are verified and Compressor speed is lower than set point or Main Header station discharge valve </li></ul></ul></ul><ul><ul><ul><li>SDV – 3134 is open DCS shall removes the Stop command “ XS – 3X44 “ to PLC and sets the local CD_X variable to the ON state. </li></ul><

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